diff --git a/y2015/control_loops/claw/claw.cc b/y2015/control_loops/claw/claw.cc
new file mode 100644
index 0000000..c1a734e
--- /dev/null
+++ b/y2015/control_loops/claw/claw.cc
@@ -0,0 +1,311 @@
+#include "y2015/control_loops/claw/claw.h"
+
+#include <algorithm>
+
+#include "aos/common/controls/control_loops.q.h"
+#include "aos/common/logging/logging.h"
+
+#include "y2015/constants.h"
+#include "y2015/control_loops/claw/claw_motor_plant.h"
+#include "aos/common/util/trapezoid_profile.h"
+
+namespace frc971 {
+namespace control_loops {
+
+using ::aos::time::Time;
+
+constexpr double kZeroingVoltage = 4.0;
+
+void ClawCappedStateFeedbackLoop::CapU() {
+  mutable_U(0, 0) = ::std::min(mutable_U(0, 0), max_voltage_);
+  mutable_U(0, 0) = ::std::max(mutable_U(0, 0), -max_voltage_);
+}
+
+double ClawCappedStateFeedbackLoop::UnsaturateOutputGoalChange() {
+  // Compute K matrix to compensate for position errors.
+  double Kp = K(0, 0);
+
+  // Compute how much we need to change R in order to achieve the change in U
+  // that was observed.
+  return -(1.0 / Kp) * (U_uncapped() - U())(0, 0);
+}
+
+Claw::Claw(control_loops::ClawQueue *claw)
+    : aos::controls::ControlLoop<control_loops::ClawQueue>(claw),
+      last_piston_edge_(Time::Now()),
+      claw_loop_(new ClawCappedStateFeedbackLoop(MakeClawLoop())),
+      claw_estimator_(constants::GetValues().claw.zeroing),
+      profile_(::aos::controls::kLoopFrequency) {}
+
+void Claw::UpdateZeroingState() {
+  if (claw_estimator_.offset_ratio_ready() < 1.0) {
+    state_ = INITIALIZING;
+  } else if (!claw_estimator_.zeroed()) {
+    state_ = ZEROING;
+  } else {
+    state_ = RUNNING;
+  }
+}
+
+void Claw::Correct() {
+  Eigen::Matrix<double, 1, 1> Y;
+  Y << claw_position();
+  claw_loop_->Correct(Y);
+}
+
+void Claw::SetClawOffset(double offset) {
+  LOG(INFO, "Changing claw offset from %f to %f.\n", claw_offset_, offset);
+  const double doffset = offset - claw_offset_;
+
+  // Adjust the height. The derivative should not need to be updated since the
+  // speed is not changing.
+  claw_loop_->mutable_X_hat(0, 0) += doffset;
+
+  // Modify claw zeroing goal.
+  claw_goal_ += doffset;
+  // Update the cached offset value to the actual value.
+  claw_offset_ = offset;
+}
+
+double Claw::estimated_claw_position() const {
+  return current_position_.joint.encoder + claw_estimator_.offset();
+}
+
+double Claw::claw_position() const {
+  return current_position_.joint.encoder + claw_offset_;
+}
+
+constexpr double kClawZeroingVelocity = 0.2;
+
+double Claw::claw_zeroing_velocity() {
+  const auto &values = constants::GetValues();
+
+  // Zeroing will work as following. At startup, record the offset of the claw.
+  // Then, start moving the claw towards where the index pulse should be. We
+  // search around it a little, and if we don't find anything, we estop.
+  // Otherwise, we're done.
+
+  const double target_pos = values.claw.zeroing.measured_index_position;
+  // How far away we need to stay from the ends of the range while zeroing.
+  constexpr double zeroing_limit = 0.1375;
+  // Keep the zeroing range within the bounds of the mechanism.
+  const double zeroing_range =
+      ::std::min(target_pos - values.claw.wrist.lower_limit - zeroing_limit,
+                 values.claw.zeroing_range);
+
+  if (claw_zeroing_velocity_ == 0) {
+    if (estimated_claw_position() > target_pos) {
+      claw_zeroing_velocity_ = -kClawZeroingVelocity;
+    } else {
+      claw_zeroing_velocity_ = kClawZeroingVelocity;
+    }
+  } else if (claw_zeroing_velocity_ > 0 &&
+             estimated_claw_position() > target_pos + zeroing_range) {
+    claw_zeroing_velocity_ = -kClawZeroingVelocity;
+  } else if (claw_zeroing_velocity_ < 0 &&
+             estimated_claw_position() < target_pos - zeroing_range) {
+    claw_zeroing_velocity_ = kClawZeroingVelocity;
+  }
+
+  return claw_zeroing_velocity_;
+}
+
+void Claw::RunIteration(const control_loops::ClawQueue::Goal *unsafe_goal,
+                        const control_loops::ClawQueue::Position *position,
+                        control_loops::ClawQueue::Output *output,
+                        control_loops::ClawQueue::Status *status) {
+  const auto &values = constants::GetValues();
+
+  if (WasReset()) {
+    LOG(ERROR, "WPILib reset! Restarting.\n");
+    claw_estimator_.Reset();
+    state_ = UNINITIALIZED;
+  }
+
+  current_position_ = *position;
+
+  // Bool to track if we should turn the motor on or not.
+  bool disable = output == nullptr;
+  double claw_goal_velocity = 0.0;
+
+  claw_estimator_.UpdateEstimate(position->joint);
+
+  if (state_ != UNINITIALIZED) {
+    Correct();
+  }
+
+  switch (state_) {
+    case UNINITIALIZED:
+      LOG(INFO, "Uninitialized.\n");
+      // Startup. Assume that we are at the origin.
+      claw_offset_ = -position->joint.encoder;
+      claw_loop_->mutable_X_hat().setZero();
+      Correct();
+      state_ = INITIALIZING;
+      disable = true;
+      break;
+
+    case INITIALIZING:
+      LOG(INFO, "Waiting for accurate initial position.\n");
+      disable = true;
+      // Update state_ to accurately represent the state of the zeroing
+      // estimator.
+      UpdateZeroingState();
+
+      if (state_ != INITIALIZING) {
+        // Set the goals to where we are now.
+        claw_goal_ = claw_position();
+      }
+      break;
+
+    case ZEROING:
+      LOG(DEBUG, "Zeroing.\n");
+
+      // Update state_.
+      UpdateZeroingState();
+      if (claw_estimator_.zeroed()) {
+        LOG(INFO, "Zeroed!\n");
+        SetClawOffset(claw_estimator_.offset());
+      } else if (!disable) {
+        claw_goal_velocity = claw_zeroing_velocity();
+        claw_goal_ +=
+            claw_goal_velocity * ::aos::controls::kLoopFrequency.ToSeconds();
+      }
+
+      // Clear the current profile state if we are zeroing.
+      {
+        Eigen::Matrix<double, 2, 1> current;
+        current.setZero();
+        current << claw_goal_, claw_goal_velocity;
+        profile_.MoveCurrentState(current);
+      }
+      break;
+
+    case RUNNING:
+      LOG(DEBUG, "Running!\n");
+
+      // Update state_.
+      UpdateZeroingState();
+      if (unsafe_goal) {
+        // Pick a set of sane defaults if none are specified.
+        if (unsafe_goal->max_velocity != 0.0) {
+          profile_.set_maximum_velocity(unsafe_goal->max_velocity);
+        } else {
+          profile_.set_maximum_velocity(2.5);
+        }
+        if (unsafe_goal->max_acceleration != 0.0) {
+          profile_.set_maximum_acceleration(unsafe_goal->max_acceleration);
+        } else {
+          profile_.set_maximum_acceleration(4.0);
+        }
+
+        const double unfiltered_goal = ::std::max(
+            ::std::min(unsafe_goal->angle, values.claw.wrist.upper_limit),
+            values.claw.wrist.lower_limit);
+        ::Eigen::Matrix<double, 2, 1> goal_state =
+            profile_.Update(unfiltered_goal, unsafe_goal->angular_velocity);
+        claw_goal_ = goal_state(0, 0);
+        claw_goal_velocity = goal_state(1, 0);
+      }
+
+      if (state_ != RUNNING && state_ != ESTOP) {
+        state_ = UNINITIALIZED;
+      }
+      break;
+
+    case ESTOP:
+      LOG(ERROR, "Estop!\n");
+      disable = true;
+      break;
+  }
+
+  // Make sure goal and position do not exceed the hardware limits if we are
+  // RUNNING.
+  if (state_ == RUNNING) {
+    // Limit goal.
+    claw_goal_ = ::std::min(claw_goal_, values.claw.wrist.upper_limit);
+    claw_goal_ = ::std::max(claw_goal_, values.claw.wrist.lower_limit);
+
+    // Check position.
+    if (claw_position() >= values.claw.wrist.upper_hard_limit ||
+        claw_position() <= values.claw.wrist.lower_hard_limit) {
+      LOG(ERROR, "Claw at %f out of bounds [%f, %f].\n", claw_position(),
+          values.claw.wrist.lower_limit, values.claw.wrist.upper_limit);
+    }
+  }
+
+  // Set the goals.
+  claw_loop_->mutable_R() << claw_goal_, claw_goal_velocity;
+
+  const double max_voltage = (state_ == RUNNING) ? 12.0 : kZeroingVoltage;
+  claw_loop_->set_max_voltage(max_voltage);
+
+  if (state_ == ESTOP) {
+    disable = true;
+  }
+  claw_loop_->Update(disable);
+
+  if (state_ == INITIALIZING || state_ == ZEROING) {
+    if (claw_loop_->U() != claw_loop_->U_uncapped()) {
+      double deltaR = claw_loop_->UnsaturateOutputGoalChange();
+
+      // Move the claw goal by the amount observed.
+      LOG(WARNING, "Moving claw goal by %f to handle saturation.\n", deltaR);
+      claw_goal_ += deltaR;
+    }
+  }
+
+  if (output) {
+    output->voltage = claw_loop_->U(0, 0);
+    if (state_ != RUNNING) {
+      output->intake_voltage = 0.0;
+      output->rollers_closed = false;
+    } else {
+      if (unsafe_goal) {
+        output->intake_voltage = unsafe_goal->intake;
+        output->rollers_closed = unsafe_goal->rollers_closed;
+      } else {
+        output->intake_voltage = 0.0;
+        output->rollers_closed = false;
+      }
+    }
+    if (output->rollers_closed != last_rollers_closed_) {
+      last_piston_edge_ = Time::Now();
+    }
+  }
+
+  status->zeroed = state_ == RUNNING;
+  status->estopped = state_ == ESTOP;
+  status->state = state_;
+  zeroing::PopulateEstimatorState(claw_estimator_, &status->zeroing_state);
+
+  status->angle = claw_loop_->X_hat(0, 0);
+  status->angular_velocity = claw_loop_->X_hat(1, 0);
+
+  if (output) {
+    status->intake = output->intake_voltage;
+  } else {
+    status->intake = 0;
+  }
+  status->goal_angle = claw_goal_;
+  status->goal_velocity = claw_goal_velocity;
+
+  if (output) {
+    status->rollers_open =
+        !output->rollers_closed &&
+        (Time::Now() - last_piston_edge_ >= values.claw.piston_switch_time);
+    status->rollers_closed =
+        output->rollers_closed &&
+        (Time::Now() - last_piston_edge_ >= values.claw.piston_switch_time);
+  } else {
+    status->rollers_open = false;
+    status->rollers_closed = false;
+  }
+
+  if (output) {
+    last_rollers_closed_ = output->rollers_closed;
+  }
+}
+
+}  // namespace control_loops
+}  // namespace frc971
diff --git a/y2015/control_loops/claw/claw.gyp b/y2015/control_loops/claw/claw.gyp
new file mode 100644
index 0000000..780f065
--- /dev/null
+++ b/y2015/control_loops/claw/claw.gyp
@@ -0,0 +1,89 @@
+{
+  'targets': [
+    {
+      'target_name': 'replay_claw',
+      'type': 'executable',
+      'variables': {
+        'no_rsync': 1,
+      },
+      'sources': [
+        'replay_claw.cc',
+      ],
+      'dependencies': [
+        'claw_queue',
+        '<(AOS)/common/controls/controls.gyp:replay_control_loop',
+        '<(AOS)/linux_code/linux_code.gyp:init',
+      ],
+    },
+    {
+      'target_name': 'claw_queue',
+      'type': 'static_library',
+      'sources': ['claw.q'],
+      'variables': {
+        'header_path': 'y2015/control_loops/claw',
+      },
+      'dependencies': [
+        '<(AOS)/common/controls/controls.gyp:control_loop_queues',
+        '<(DEPTH)/frc971/control_loops/control_loops.gyp:queues',
+      ],
+      'export_dependent_settings': [
+        '<(AOS)/common/controls/controls.gyp:control_loop_queues',
+        '<(DEPTH)/frc971/control_loops/control_loops.gyp:queues',
+
+      ],
+      'includes': ['../../../aos/build/queues.gypi'],
+    },
+    {
+      'target_name': 'claw_lib',
+      'type': 'static_library',
+      'sources': [
+        'claw.cc',
+        'claw_motor_plant.cc',
+      ],
+      'dependencies': [
+        'claw_queue',
+        '<(AOS)/common/controls/controls.gyp:control_loop',
+        '<(AOS)/common/common.gyp:time',
+        '<(AOS)/common/util/util.gyp:trapezoid_profile',
+        '<(DEPTH)/y2015/y2015.gyp:constants',
+        '<(DEPTH)/frc971/control_loops/control_loops.gyp:state_feedback_loop',
+        '<(DEPTH)/frc971/zeroing/zeroing.gyp:zeroing',
+      ],
+      'export_dependent_settings': [
+        'claw_queue',
+        '<(AOS)/common/controls/controls.gyp:control_loop',
+        '<(AOS)/common/common.gyp:time',
+        '<(AOS)/common/util/util.gyp:trapezoid_profile',
+        '<(DEPTH)/frc971/control_loops/control_loops.gyp:state_feedback_loop',
+        '<(DEPTH)/frc971/zeroing/zeroing.gyp:zeroing',
+      ],
+    },
+    {
+      'target_name': 'claw_lib_test',
+      'type': 'executable',
+      'sources': [
+        'claw_lib_test.cc',
+      ],
+      'dependencies': [
+        '<(EXTERNALS):gtest',
+        'claw_lib',
+        '<(DEPTH)/frc971/control_loops/control_loops.gyp:state_feedback_loop',
+        '<(AOS)/common/controls/controls.gyp:control_loop_test',
+        '<(AOS)/common/common.gyp:time',
+        '<(DEPTH)/frc971/control_loops/control_loops.gyp:position_sensor_sim',
+        '<(DEPTH)/frc971/control_loops/control_loops.gyp:team_number_test_environment',
+      ],
+    },
+    {
+      'target_name': 'claw',
+      'type': 'executable',
+      'sources': [
+        'claw_main.cc',
+      ],
+      'dependencies': [
+        '<(AOS)/linux_code/linux_code.gyp:init',
+        'claw_lib',
+      ],
+    },
+  ],
+}
diff --git a/y2015/control_loops/claw/claw.h b/y2015/control_loops/claw/claw.h
new file mode 100644
index 0000000..02e5398
--- /dev/null
+++ b/y2015/control_loops/claw/claw.h
@@ -0,0 +1,116 @@
+#ifndef Y2015_CONTROL_LOOPS_CLAW_H_
+#define Y2015_CONTROL_LOOPS_CLAW_H_
+
+#include <memory>
+
+#include "aos/common/controls/control_loop.h"
+#include "aos/common/time.h"
+#include "aos/common/util/trapezoid_profile.h"
+#include "frc971/control_loops/state_feedback_loop.h"
+#include "y2015/control_loops/claw/claw.q.h"
+#include "y2015/control_loops/claw/claw_motor_plant.h"
+#include "frc971/zeroing/zeroing.h"
+
+namespace frc971 {
+namespace control_loops {
+namespace testing {
+class ClawTest_DisabledGoal_Test;
+class ClawTest_GoalPositiveWindup_Test;
+class ClawTest_GoalNegativeWindup_Test;
+}  // namespace testing
+
+class ClawCappedStateFeedbackLoop : public StateFeedbackLoop<2, 1, 1> {
+ public:
+  ClawCappedStateFeedbackLoop(StateFeedbackLoop<2, 1, 1> &&loop)
+      : StateFeedbackLoop<2, 1, 1>(::std::move(loop)), max_voltage_(12.0) {}
+
+  void set_max_voltage(double max_voltage) {
+    max_voltage_ = ::std::max(0.0, ::std::min(12.0, max_voltage));
+  }
+
+  void CapU() override;
+
+  // Returns the amount to change the position goal in order to no longer
+  // saturate the controller.
+  double UnsaturateOutputGoalChange();
+
+ private:
+  double max_voltage_;
+};
+
+class Claw : public aos::controls::ControlLoop<control_loops::ClawQueue> {
+ public:
+  enum State {
+    // Waiting to receive data before doing anything.
+    UNINITIALIZED = 0,
+    // Estimating the starting location.
+    INITIALIZING = 1,
+    // Moving to find an index pulse.
+    ZEROING = 2,
+    // Normal operation.
+    RUNNING = 3,
+    // Internal error caused the claw to abort.
+    ESTOP = 4,
+  };
+
+  int state() { return state_; }
+
+  explicit Claw(
+      control_loops::ClawQueue *claw_queue = &control_loops::claw_queue);
+
+ protected:
+  virtual void RunIteration(const control_loops::ClawQueue::Goal *goal,
+                            const control_loops::ClawQueue::Position *position,
+                            control_loops::ClawQueue::Output *output,
+                            control_loops::ClawQueue::Status *status);
+
+ private:
+  friend class testing::ClawTest_DisabledGoal_Test;
+  friend class testing::ClawTest_GoalPositiveWindup_Test;
+  friend class testing::ClawTest_GoalNegativeWindup_Test;
+
+  // Sets state_ to the correct state given the current state of the zeroing
+  // estimator.
+  void UpdateZeroingState();
+  void SetClawOffset(double offset);
+  // Corrects the Observer with the current position.
+  void Correct();
+
+  // Getter for the current claw position.
+  double claw_position() const;
+  // Our best guess at the current position of the claw.
+  double estimated_claw_position() const;
+  // Returns the current zeroing velocity for the claw. If the subsystem is too
+  // far away from the center, it will switch directions.
+  double claw_zeroing_velocity();
+
+  State state_ = UNINITIALIZED;
+
+  // The time when we last changed the claw piston state.
+  ::aos::time::Time last_piston_edge_;
+
+  // The state feedback control loop to talk to.
+  ::std::unique_ptr<ClawCappedStateFeedbackLoop> claw_loop_;
+
+  // Latest position from queue.
+  control_loops::ClawQueue::Position current_position_;
+  // Zeroing estimator for claw.
+  zeroing::ZeroingEstimator claw_estimator_;
+
+  // The goal for the claw.
+  double claw_goal_ = 0.0;
+  // Current velocity to move at while zeroing.
+  double claw_zeroing_velocity_ = 0.0;
+  // Offsets from the encoder position to the absolute position.
+  double claw_offset_ = 0.0;
+
+  // Whether claw was closed last cycle.
+  bool last_rollers_closed_ = false;
+
+  ::aos::util::TrapezoidProfile profile_;
+};
+
+}  // namespace control_loops
+}  // namespace frc971
+
+#endif  // Y2015_CONTROL_LOOPS_CLAW_H_
diff --git a/y2015/control_loops/claw/claw.q b/y2015/control_loops/claw/claw.q
new file mode 100644
index 0000000..8da1c20
--- /dev/null
+++ b/y2015/control_loops/claw/claw.q
@@ -0,0 +1,81 @@
+package frc971.control_loops;
+
+import "aos/common/controls/control_loops.q";
+import "frc971/control_loops/control_loops.q";
+
+queue_group ClawQueue {
+  implements aos.control_loops.ControlLoop;
+
+  // All angles are in radians with 0 sticking straight out the front. Rotating
+  // up and into the robot is positive. Positive output voltage moves in the
+  // direction of positive encoder values.
+
+  message Goal {
+    // Angle of wrist joint.
+    double angle;
+    // Angular velocity of wrist.
+    float angular_velocity;
+    // Maximum profile velocity, or 0 for the default.
+    float max_velocity;
+    // Maximum profile acceleration, or 0 for the default.
+    float max_acceleration;
+    // Voltage of intake rollers. Positive means sucking in, negative means
+    // spitting out.
+    double intake;
+
+    // true to signal the rollers to close.
+    bool rollers_closed;
+  };
+
+  message Position {
+    PotAndIndexPosition joint;
+  };
+
+  message Output {
+    // Voltage for intake motors. Positive is sucking in, negative is spitting
+    // out.
+    double intake_voltage;
+    // Voltage for claw motor.
+    double voltage;
+
+    // true to signal the rollers to close.
+    bool rollers_closed;
+  };
+
+  message Status {
+    // Is claw zeroed?
+    bool zeroed;
+    // Did the claw estop?
+    bool estopped;
+    // The internal state of the claw state machine.
+    uint32_t state;
+    EstimatorState zeroing_state;
+
+    // Estimated angle of wrist joint.
+    double angle;
+    // Estimated angular velocity of wrist.
+    float angular_velocity;
+
+    // Goal angle of wrist joint.
+    double goal_angle;
+    float goal_velocity;
+    // Voltage of intake rollers. Positive means sucking in, negative means
+    // spitting out.
+    double intake;
+
+    // True iff there has been enough time since we actuated the rollers outward
+    // that they should be there.
+    bool rollers_open;
+    // True iff there has been enough time since we actuated the rollers closed
+    // that they should be there.
+    bool rollers_closed;
+  };
+
+  queue Goal goal;
+  queue Position position;
+  queue Output output;
+  queue Status status;
+};
+
+queue_group ClawQueue claw_queue;
+
diff --git a/y2015/control_loops/claw/claw_lib_test.cc b/y2015/control_loops/claw/claw_lib_test.cc
new file mode 100644
index 0000000..10fcc07
--- /dev/null
+++ b/y2015/control_loops/claw/claw_lib_test.cc
@@ -0,0 +1,347 @@
+#include <math.h>
+#include <unistd.h>
+
+#include <memory>
+
+#include "gtest/gtest.h"
+#include "aos/common/queue.h"
+#include "aos/common/time.h"
+#include "aos/common/controls/control_loop_test.h"
+#include "y2015/control_loops/claw/claw.q.h"
+#include "y2015/control_loops/claw/claw.h"
+#include "frc971/control_loops/position_sensor_sim.h"
+#include "y2015/constants.h"
+#include "frc971/control_loops/team_number_test_environment.h"
+
+using ::aos::time::Time;
+
+namespace frc971 {
+namespace control_loops {
+namespace testing {
+
+// Class which simulates the claw and sends out queue messages with the
+// position.
+class ClawSimulation {
+ public:
+  // Constructs a claw simulation.
+  ClawSimulation()
+      : claw_plant_(new StateFeedbackPlant<2, 1, 1>(MakeClawPlant())),
+        pot_and_encoder_(constants::GetValues().claw.zeroing.index_difference),
+        claw_queue_(".frc971.control_loops.claw_queue", 0x9d7452fb,
+                    ".frc971.control_loops.claw_queue.goal",
+                    ".frc971.control_loops.claw_queue.position",
+                    ".frc971.control_loops.claw_queue.output",
+                    ".frc971.control_loops.claw_queue.status") {
+    InitializePosition(constants::GetValues().claw.wrist.lower_limit);
+  }
+
+  void InitializePosition(double start_pos) {
+    InitializePosition(start_pos,
+        constants::GetValues().claw.zeroing.measured_index_position);
+  }
+
+  void InitializePosition(double start_pos, double index_pos) {
+    InitializePosition(start_pos,
+        // This gives us a standard deviation of ~9 degrees on the pot noise.
+        constants::GetValues().claw.zeroing.index_difference / 10.0,
+        index_pos);
+  }
+
+  // Do specific initialization for the sensors.
+  void InitializePosition(double start_pos,
+                         double pot_noise_stddev,
+                         double index_pos) {
+    // Update internal state.
+    claw_plant_->mutable_X(0, 0) = start_pos;
+    // Zero velocity.
+    claw_plant_->mutable_X(1, 0) = 0.0;
+
+    pot_and_encoder_.Initialize(start_pos, pot_noise_stddev, index_pos);
+  }
+
+  // Sends a queue message with the position.
+  void SendPositionMessage() {
+    ::aos::ScopedMessagePtr<control_loops::ClawQueue::Position> position =
+      claw_queue_.position.MakeMessage();
+    pot_and_encoder_.GetSensorValues(&position->joint);
+    position.Send();
+  }
+
+  // Simulates for a single timestep.
+  void Simulate() {
+    EXPECT_TRUE(claw_queue_.output.FetchLatest());
+
+    // Feed voltages into physics simulation.
+    claw_plant_->mutable_U() << claw_queue_.output->voltage;
+    claw_plant_->Update();
+
+    const double wrist_angle = claw_plant_->Y(0, 0);
+
+    // TODO(danielp): Sanity checks.
+
+    pot_and_encoder_.MoveTo(wrist_angle);
+  }
+
+ private:
+  ::std::unique_ptr<StateFeedbackPlant<2, 1, 1>> claw_plant_;
+  PositionSensorSimulator pot_and_encoder_;
+
+  ClawQueue claw_queue_;
+};
+
+class ClawTest : public ::aos::testing::ControlLoopTest {
+ protected:
+  ClawTest()
+      : claw_queue_(".frc971.control_loops.claw_queue", 0x9d7452fb,
+                    ".frc971.control_loops.claw_queue.goal",
+                    ".frc971.control_loops.claw_queue.position",
+                    ".frc971.control_loops.claw_queue.output",
+                    ".frc971.control_loops.claw_queue.status"),
+        claw_(&claw_queue_),
+        claw_plant_() {
+    set_team_id(kTeamNumber);
+  }
+
+  void VerifyNearGoal() {
+    claw_queue_.goal.FetchLatest();
+    claw_queue_.status.FetchLatest();
+    EXPECT_NEAR(claw_queue_.goal->angle,
+                claw_queue_.status->angle,
+                10.0);
+
+    EXPECT_TRUE(claw_queue_.status->zeroed);
+    EXPECT_FALSE(claw_queue_.status->estopped);
+  }
+
+  // Runs one iteration of the whole simulation.
+  void RunIteration(bool enabled = true) {
+    SendMessages(enabled);
+
+    claw_plant_.SendPositionMessage();
+    claw_.Iterate();
+    claw_plant_.Simulate();
+
+    TickTime();
+  }
+
+  // Runs iterations until the specified amount of simulated time has elapsed.
+  void RunForTime(const Time &run_for, bool enabled = true) {
+    const auto start_time = Time::Now();
+    while (Time::Now() < start_time + run_for) {
+      RunIteration(enabled);
+    }
+  }
+
+  // Create a new instance of the test queue so that it invalidates the queue
+  // that it points to.  Otherwise, we will have a pointed to
+  // shared memory that is no longer valid.
+  ClawQueue claw_queue_;
+
+  // Create a control loop and simulation.
+  Claw claw_;
+  ClawSimulation claw_plant_;
+};
+
+// Tests that the loop does nothing when the goal is our lower limit.
+TEST_F(ClawTest, DoesNothing) {
+  const auto &values = constants::GetValues();
+  ASSERT_TRUE(claw_queue_.goal.MakeWithBuilder()
+      .angle(values.claw.wrist.lower_limit)
+      .Send());
+
+  RunForTime(Time::InSeconds(6));
+
+  // We should not have moved.
+  VerifyNearGoal();
+}
+
+// NOTE: Claw zeroing is a little annoying because we only hit one index pulse
+// in our entire range of motion.
+
+// Tests that the loop zeroing works with normal values.
+TEST_F(ClawTest, Zeroes) {
+  // It should zero itself if we run it for awhile.
+  ASSERT_TRUE(claw_queue_.goal.MakeWithBuilder()
+      .angle(M_PI / 4.0)
+      .Send());
+
+  RunForTime(Time::InSeconds(6));
+
+  ASSERT_TRUE(claw_queue_.status.FetchLatest());
+  EXPECT_TRUE(claw_queue_.status->zeroed);
+  EXPECT_EQ(Claw::RUNNING, claw_queue_.status->state);
+}
+
+// Tests that claw zeroing fails if the index pulse occurs too close to the end
+// of the range.
+TEST_F(ClawTest, BadIndexPosition) {
+  const auto values = constants::GetValues();
+  claw_plant_.InitializePosition(values.claw.wrist.lower_limit,
+                                 values.claw.wrist.upper_limit);
+
+  ASSERT_TRUE(claw_queue_.goal.MakeWithBuilder()
+      .angle(M_PI / 4.0)
+      .Send());
+
+  // The zeroing is going to take its sweet time on this one, so we had better
+  // run it for longer.
+  RunForTime(Time::InMS(12000));
+
+  ASSERT_TRUE(claw_queue_.status.FetchLatest());
+  EXPECT_FALSE(claw_queue_.status->zeroed);
+  EXPECT_FALSE(claw_queue_.status->estopped);
+}
+
+// Tests that we can reach a reasonable goal.
+TEST_F(ClawTest, ReachesGoal) {
+  ASSERT_TRUE(claw_queue_.goal.MakeWithBuilder()
+      .angle(M_PI / 4.0)
+      .Send());
+
+  RunForTime(Time::InSeconds(6));
+
+  VerifyNearGoal();
+}
+
+// Tests that it doesn't try to move past the physical range of the mechanism.
+TEST_F(ClawTest, RespectsRange) {
+  const auto &values = constants::GetValues();
+  // Upper limit
+  ASSERT_TRUE(claw_queue_.goal.MakeWithBuilder()
+      .angle(values.claw.wrist.upper_hard_limit + 5.0)
+      .Send());
+
+  RunForTime(Time::InSeconds(7));
+
+  claw_queue_.status.FetchLatest();
+  EXPECT_NEAR(values.claw.wrist.upper_limit,
+              claw_queue_.status->angle,
+              2.0 * M_PI / 180.0);
+
+  // Lower limit.
+  ASSERT_TRUE(claw_queue_.goal.MakeWithBuilder()
+      .angle(values.claw.wrist.lower_hard_limit - 5.0)
+      .Send());
+
+  RunForTime(Time::InMS(6000));
+
+  claw_queue_.status.FetchLatest();
+  EXPECT_NEAR(values.claw.wrist.lower_limit,
+              claw_queue_.status->angle,
+              2.0 * M_PI / 180.0);
+}
+
+// Tests that starting at the lower hardstop doesn't cause an abort.
+TEST_F(ClawTest, LowerHardstopStartup) {
+  claw_plant_.InitializePosition(
+      constants::GetValues().claw.wrist.lower_hard_limit);
+  ASSERT_TRUE(claw_queue_.goal.MakeWithBuilder()
+      .angle(M_PI / 4.0)
+      .Send());
+  RunForTime(Time::InSeconds(6));
+
+  VerifyNearGoal();
+}
+
+// Tests that starting at the upper hardstop doesn't cause an abort.
+TEST_F(ClawTest, UpperHardstopStartup) {
+  claw_plant_.InitializePosition(
+      constants::GetValues().claw.wrist.upper_hard_limit);
+  ASSERT_TRUE(claw_queue_.goal.MakeWithBuilder()
+      .angle(M_PI / 4.0)
+      .Send());
+  // Zeroing will take a long time here.
+  RunForTime(Time::InSeconds(15));
+
+  VerifyNearGoal();
+}
+
+
+// Tests that not having a goal doesn't break anything.
+TEST_F(ClawTest, NoGoal) {
+  RunForTime(Time::InMS(50));
+}
+
+// Tests that a WPILib reset results in rezeroing.
+TEST_F(ClawTest, WpilibReset) {
+  ASSERT_TRUE(claw_queue_.goal.MakeWithBuilder()
+      .angle(M_PI / 4.0)
+      .Send());
+
+  RunForTime(Time::InSeconds(6));
+  VerifyNearGoal();
+
+  SimulateSensorReset();
+  RunForTime(Time::InMS(100));
+  ASSERT_TRUE(claw_queue_.status.FetchLatest());
+  EXPECT_NE(Claw::RUNNING, claw_queue_.status->state);
+
+  // Once again, it's going to take us awhile to rezero since we moved away from
+  // our index pulse.
+  RunForTime(Time::InSeconds(6));
+  VerifyNearGoal();
+}
+
+// Tests that internal goals don't change while disabled.
+TEST_F(ClawTest, DisabledGoal) {
+  ASSERT_TRUE(claw_queue_.goal.MakeWithBuilder()
+      .angle(M_PI / 4.0)
+      .Send());
+
+  RunForTime(Time::InMS(100), false);
+  EXPECT_EQ(0.0, claw_.claw_goal_);
+
+  // Now make sure they move correctly.
+  RunForTime(Time::InMS(1000), true);
+  EXPECT_NE(0.0, claw_.claw_goal_);
+}
+
+// Tests that the claw zeroing goals don't wind up too far.
+TEST_F(ClawTest, GoalPositiveWindup) {
+  ASSERT_TRUE(claw_queue_.goal.MakeWithBuilder()
+      .angle(M_PI / 4.0)
+      .Send());
+
+  while (claw_.state() != Claw::ZEROING) {
+    RunIteration();
+  }
+
+  // Kick it.
+  RunForTime(Time::InMS(50));
+  const double orig_claw_goal = claw_.claw_goal_;
+  claw_.claw_goal_ += 100.0;
+
+  RunIteration();
+  EXPECT_NEAR(orig_claw_goal, claw_.claw_goal_, 0.10);
+
+  RunIteration();
+
+  EXPECT_EQ(claw_.claw_loop_->U(), claw_.claw_loop_->U_uncapped());
+}
+
+// Tests that the claw zeroing goals don't wind up too far.
+TEST_F(ClawTest, GoalNegativeWindup) {
+  ASSERT_TRUE(claw_queue_.goal.MakeWithBuilder()
+      .angle(M_PI / 4.0)
+      .Send());
+
+  while (claw_.state() != Claw::ZEROING) {
+    RunIteration();
+  }
+
+  // Kick it.
+  RunForTime(Time::InMS(50));
+  double orig_claw_goal = claw_.claw_goal_;
+  claw_.claw_goal_ -= 100.0;
+
+  RunIteration();
+  EXPECT_NEAR(orig_claw_goal, claw_.claw_goal_, 0.10);
+
+  RunIteration();
+
+  EXPECT_EQ(claw_.claw_loop_->U(), claw_.claw_loop_->U_uncapped());
+}
+
+}  // namespace testing
+}  // namespace control_loops
+}  // namespace frc971
diff --git a/y2015/control_loops/claw/claw_main.cc b/y2015/control_loops/claw/claw_main.cc
new file mode 100644
index 0000000..d1b869c
--- /dev/null
+++ b/y2015/control_loops/claw/claw_main.cc
@@ -0,0 +1,11 @@
+#include "y2015/control_loops/claw/claw.h"
+
+#include "aos/linux_code/init.h"
+
+int main() {
+  ::aos::Init();
+  frc971::control_loops::Claw claw;
+  claw.Run();
+  ::aos::Cleanup();
+  return 0;
+}
diff --git a/y2015/control_loops/claw/claw_motor_plant.cc b/y2015/control_loops/claw/claw_motor_plant.cc
new file mode 100644
index 0000000..5f5c206
--- /dev/null
+++ b/y2015/control_loops/claw/claw_motor_plant.cc
@@ -0,0 +1,49 @@
+#include "y2015/control_loops/claw/claw_motor_plant.h"
+
+#include <vector>
+
+#include "frc971/control_loops/state_feedback_loop.h"
+
+namespace frc971 {
+namespace control_loops {
+
+StateFeedbackPlantCoefficients<2, 1, 1> MakeClawPlantCoefficients() {
+  Eigen::Matrix<double, 2, 2> A;
+  A << 1.0, 0.00482455476758, 0.0, 0.930652495326;
+  Eigen::Matrix<double, 2, 1> B;
+  B << 6.97110924671e-05, 0.0275544125308;
+  Eigen::Matrix<double, 1, 2> C;
+  C << 1, 0;
+  Eigen::Matrix<double, 1, 1> D;
+  D << 0;
+  Eigen::Matrix<double, 1, 1> U_max;
+  U_max << 12.0;
+  Eigen::Matrix<double, 1, 1> U_min;
+  U_min << -12.0;
+  return StateFeedbackPlantCoefficients<2, 1, 1>(A, B, C, D, U_max, U_min);
+}
+
+StateFeedbackController<2, 1, 1> MakeClawController() {
+  Eigen::Matrix<double, 2, 1> L;
+  L << 0.998251427366, 26.9874526231;
+  Eigen::Matrix<double, 1, 2> K;
+  K << 74.4310031124, 4.72251126222;
+  Eigen::Matrix<double, 2, 2> A_inv;
+  A_inv << 1.0, -0.00518405612386, 0.0, 1.07451492907;
+  return StateFeedbackController<2, 1, 1>(L, K, A_inv, MakeClawPlantCoefficients());
+}
+
+StateFeedbackPlant<2, 1, 1> MakeClawPlant() {
+  ::std::vector< ::std::unique_ptr<StateFeedbackPlantCoefficients<2, 1, 1>>> plants(1);
+  plants[0] = ::std::unique_ptr<StateFeedbackPlantCoefficients<2, 1, 1>>(new StateFeedbackPlantCoefficients<2, 1, 1>(MakeClawPlantCoefficients()));
+  return StateFeedbackPlant<2, 1, 1>(&plants);
+}
+
+StateFeedbackLoop<2, 1, 1> MakeClawLoop() {
+  ::std::vector< ::std::unique_ptr<StateFeedbackController<2, 1, 1>>> controllers(1);
+  controllers[0] = ::std::unique_ptr<StateFeedbackController<2, 1, 1>>(new StateFeedbackController<2, 1, 1>(MakeClawController()));
+  return StateFeedbackLoop<2, 1, 1>(&controllers);
+}
+
+}  // namespace control_loops
+}  // namespace frc971
diff --git a/y2015/control_loops/claw/claw_motor_plant.h b/y2015/control_loops/claw/claw_motor_plant.h
new file mode 100644
index 0000000..6cb9cdb
--- /dev/null
+++ b/y2015/control_loops/claw/claw_motor_plant.h
@@ -0,0 +1,20 @@
+#ifndef Y2015_CONTROL_LOOPS_CLAW_CLAW_MOTOR_PLANT_H_
+#define Y2015_CONTROL_LOOPS_CLAW_CLAW_MOTOR_PLANT_H_
+
+#include "frc971/control_loops/state_feedback_loop.h"
+
+namespace frc971 {
+namespace control_loops {
+
+StateFeedbackPlantCoefficients<2, 1, 1> MakeClawPlantCoefficients();
+
+StateFeedbackController<2, 1, 1> MakeClawController();
+
+StateFeedbackPlant<2, 1, 1> MakeClawPlant();
+
+StateFeedbackLoop<2, 1, 1> MakeClawLoop();
+
+}  // namespace control_loops
+}  // namespace frc971
+
+#endif  // Y2015_CONTROL_LOOPS_CLAW_CLAW_MOTOR_PLANT_H_
diff --git a/y2015/control_loops/claw/replay_claw.cc b/y2015/control_loops/claw/replay_claw.cc
new file mode 100644
index 0000000..50673e4
--- /dev/null
+++ b/y2015/control_loops/claw/replay_claw.cc
@@ -0,0 +1,24 @@
+#include "aos/common/controls/replay_control_loop.h"
+#include "aos/linux_code/init.h"
+
+#include "y2015/control_loops/claw/claw.q.h"
+
+// Reads one or more log files and sends out all the queue messages (in the
+// correct order and at the correct time) to feed a "live" claw process.
+
+int main(int argc, char **argv) {
+  if (argc <= 1) {
+    fprintf(stderr, "Need at least one file to replay!\n");
+    return EXIT_FAILURE;
+  }
+
+  ::aos::InitNRT();
+
+  ::aos::controls::ControlLoopReplayer<::frc971::control_loops::ClawQueue>
+      replayer(&::frc971::control_loops::claw_queue, "claw");
+  for (int i = 1; i < argc; ++i) {
+    replayer.ProcessFile(argv[i]);
+  }
+
+  ::aos::Cleanup();
+}
diff --git a/y2015/control_loops/drivetrain/drivetrain.cc b/y2015/control_loops/drivetrain/drivetrain.cc
new file mode 100644
index 0000000..22a5d48
--- /dev/null
+++ b/y2015/control_loops/drivetrain/drivetrain.cc
@@ -0,0 +1,777 @@
+#include "y2015/control_loops/drivetrain/drivetrain.h"
+
+#include <stdio.h>
+#include <sched.h>
+#include <cmath>
+#include <memory>
+#include "Eigen/Dense"
+
+#include "aos/common/logging/logging.h"
+#include "aos/common/controls/polytope.h"
+#include "aos/common/commonmath.h"
+#include "aos/common/logging/queue_logging.h"
+#include "aos/common/logging/matrix_logging.h"
+
+#include "y2015/constants.h"
+#include "frc971/control_loops/state_feedback_loop.h"
+#include "frc971/control_loops/coerce_goal.h"
+#include "y2015/control_loops/drivetrain/polydrivetrain_cim_plant.h"
+#include "y2015/control_loops/drivetrain/drivetrain.q.h"
+#include "frc971/queues/gyro.q.h"
+#include "frc971/shifter_hall_effect.h"
+
+// A consistent way to mark code that goes away without shifters. It's still
+// here because we will have shifters again in the future.
+#define HAVE_SHIFTERS 0
+
+using frc971::sensors::gyro_reading;
+
+namespace frc971 {
+namespace control_loops {
+
+class DrivetrainMotorsSS {
+ public:
+  class LimitedDrivetrainLoop : public StateFeedbackLoop<4, 2, 2> {
+   public:
+    LimitedDrivetrainLoop(StateFeedbackLoop<4, 2, 2> &&loop)
+        : StateFeedbackLoop<4, 2, 2>(::std::move(loop)),
+        U_Poly_((Eigen::Matrix<double, 4, 2>() << 1, 0,
+                 -1, 0,
+                 0, 1,
+                 0, -1).finished(),
+                (Eigen::Matrix<double, 4, 1>() << 12.0, 12.0,
+                 12.0, 12.0).finished()) {
+      ::aos::controls::HPolytope<0>::Init();
+      T << 1, -1, 1, 1;
+      T_inverse = T.inverse();
+    }
+
+    bool output_was_capped() const {
+      return output_was_capped_;
+    }
+
+   private:
+    virtual void CapU() {
+      const Eigen::Matrix<double, 4, 1> error = R() - X_hat();
+
+      if (::std::abs(U(0, 0)) > 12.0 || ::std::abs(U(1, 0)) > 12.0) {
+        mutable_U() =
+            U() * 12.0 / ::std::max(::std::abs(U(0, 0)), ::std::abs(U(1, 0)));
+        LOG_MATRIX(DEBUG, "U is now", U());
+        // TODO(Austin): Figure out why the polytope stuff wasn't working and
+        // remove this hack.
+        output_was_capped_ = true;
+        return;
+
+        LOG_MATRIX(DEBUG, "U at start", U());
+        LOG_MATRIX(DEBUG, "R at start", R());
+        LOG_MATRIX(DEBUG, "Xhat at start", X_hat());
+
+        Eigen::Matrix<double, 2, 2> position_K;
+        position_K << K(0, 0), K(0, 2),
+                   K(1, 0), K(1, 2);
+        Eigen::Matrix<double, 2, 2> velocity_K;
+        velocity_K << K(0, 1), K(0, 3),
+                   K(1, 1), K(1, 3);
+
+        Eigen::Matrix<double, 2, 1> position_error;
+        position_error << error(0, 0), error(2, 0);
+        const auto drive_error = T_inverse * position_error;
+        Eigen::Matrix<double, 2, 1> velocity_error;
+        velocity_error << error(1, 0), error(3, 0);
+        LOG_MATRIX(DEBUG, "error", error);
+
+        const auto &poly = U_Poly_;
+        const Eigen::Matrix<double, 4, 2> pos_poly_H =
+            poly.H() * position_K * T;
+        const Eigen::Matrix<double, 4, 1> pos_poly_k =
+            poly.k() - poly.H() * velocity_K * velocity_error;
+        const ::aos::controls::HPolytope<2> pos_poly(pos_poly_H, pos_poly_k);
+
+        Eigen::Matrix<double, 2, 1> adjusted_pos_error;
+        {
+          const auto &P = drive_error;
+
+          Eigen::Matrix<double, 1, 2> L45;
+          L45 << ::aos::sign(P(1, 0)), -::aos::sign(P(0, 0));
+          const double w45 = 0;
+
+          Eigen::Matrix<double, 1, 2> LH;
+          if (::std::abs(P(0, 0)) > ::std::abs(P(1, 0))) {
+            LH << 0, 1;
+          } else {
+            LH << 1, 0;
+          }
+          const double wh = LH.dot(P);
+
+          Eigen::Matrix<double, 2, 2> standard;
+          standard << L45, LH;
+          Eigen::Matrix<double, 2, 1> W;
+          W << w45, wh;
+          const Eigen::Matrix<double, 2, 1> intersection =
+              standard.inverse() * W;
+
+          bool is_inside_h;
+          const auto adjusted_pos_error_h =
+              DoCoerceGoal(pos_poly, LH, wh, drive_error, &is_inside_h);
+          const auto adjusted_pos_error_45 =
+              DoCoerceGoal(pos_poly, L45, w45, intersection, nullptr);
+          if (pos_poly.IsInside(intersection)) {
+            adjusted_pos_error = adjusted_pos_error_h;
+          } else {
+            if (is_inside_h) {
+              if (adjusted_pos_error_h.norm() > adjusted_pos_error_45.norm()) {
+                adjusted_pos_error = adjusted_pos_error_h;
+              } else {
+                adjusted_pos_error = adjusted_pos_error_45;
+              }
+            } else {
+              adjusted_pos_error = adjusted_pos_error_45;
+            }
+          }
+        }
+
+        LOG_MATRIX(DEBUG, "adjusted_pos_error", adjusted_pos_error);
+        mutable_U() =
+            velocity_K * velocity_error + position_K * T * adjusted_pos_error;
+        LOG_MATRIX(DEBUG, "U is now", U());
+      } else {
+        output_was_capped_ = false;
+      }
+    }
+
+    const ::aos::controls::HPolytope<2> U_Poly_;
+    Eigen::Matrix<double, 2, 2> T, T_inverse;
+    bool output_was_capped_ = false;;
+  };
+
+  DrivetrainMotorsSS()
+      : loop_(new LimitedDrivetrainLoop(
+            constants::GetValues().make_drivetrain_loop())),
+        filtered_offset_(0.0),
+        gyro_(0.0),
+        left_goal_(0.0),
+        right_goal_(0.0),
+        raw_left_(0.0),
+        raw_right_(0.0) {
+    // Low gear on both.
+    loop_->set_controller_index(0);
+  }
+
+  void SetGoal(double left, double left_velocity, double right,
+               double right_velocity) {
+    left_goal_ = left;
+    right_goal_ = right;
+    loop_->mutable_R() << left, left_velocity, right, right_velocity;
+  }
+  void SetRawPosition(double left, double right) {
+    raw_right_ = right;
+    raw_left_ = left;
+    Eigen::Matrix<double, 2, 1> Y;
+    Y << left + filtered_offset_, right - filtered_offset_;
+    loop_->Correct(Y);
+  }
+  void SetPosition(double left, double right, double gyro) {
+    // Decay the offset quickly because this gyro is great.
+    const double offset =
+        (right - left - gyro * constants::GetValues().turn_width) / 2.0;
+    filtered_offset_ = 0.25 * offset + 0.75 * filtered_offset_;
+    gyro_ = gyro;
+    SetRawPosition(left, right);
+  }
+
+  void SetExternalMotors(double left_voltage, double right_voltage) {
+    loop_->mutable_U() << left_voltage, right_voltage;
+  }
+
+  void Update(bool stop_motors, bool enable_control_loop) {
+    if (enable_control_loop) {
+      loop_->Update(stop_motors);
+    } else {
+      if (stop_motors) {
+        loop_->mutable_U().setZero();
+        loop_->mutable_U_uncapped().setZero();
+      }
+      loop_->UpdateObserver();
+    }
+    ::Eigen::Matrix<double, 4, 1> E = loop_->R() - loop_->X_hat();
+    LOG_MATRIX(DEBUG, "E", E);
+  }
+
+  double GetEstimatedRobotSpeed() const {
+    // lets just call the average of left and right velocities close enough
+    return (loop_->X_hat(1, 0) + loop_->X_hat(3, 0)) / 2;
+  }
+
+  double GetEstimatedLeftEncoder() const {
+    return loop_->X_hat(0, 0);
+  }
+
+  double GetEstimatedRightEncoder() const {
+    return loop_->X_hat(2, 0);
+  }
+
+  bool OutputWasCapped() const {
+    return loop_->output_was_capped();
+  }
+
+  void SendMotors(DrivetrainQueue::Output *output) const {
+    if (output) {
+      output->left_voltage = loop_->U(0, 0);
+      output->right_voltage = loop_->U(1, 0);
+      output->left_high = false;
+      output->right_high = false;
+    }
+  }
+
+  const LimitedDrivetrainLoop &loop() const { return *loop_; }
+
+ private:
+  ::std::unique_ptr<LimitedDrivetrainLoop> loop_;
+
+  double filtered_offset_;
+  double gyro_;
+  double left_goal_;
+  double right_goal_;
+  double raw_left_;
+  double raw_right_;
+};
+
+class PolyDrivetrain {
+ public:
+
+  enum Gear {
+    HIGH,
+    LOW,
+    SHIFTING_UP,
+    SHIFTING_DOWN
+  };
+  // Stall Torque in N m
+  static constexpr double kStallTorque = 2.42;
+  // Stall Current in Amps
+  static constexpr double kStallCurrent = 133.0;
+  // Free Speed in RPM. Used number from last year.
+  static constexpr double kFreeSpeed = 4650.0;
+  // Free Current in Amps
+  static constexpr double kFreeCurrent = 2.7;
+  // Moment of inertia of the drivetrain in kg m^2
+  // Just borrowed from last year.
+  static constexpr double J = 10;
+  // Mass of the robot, in kg.
+  static constexpr double m = 68;
+  // Radius of the robot, in meters (from last year).
+  static constexpr double rb = 0.9603 / 2.0;
+  static constexpr double kWheelRadius = 0.0515938;
+  // Resistance of the motor, divided by the number of motors.
+  static constexpr double kR = (12.0 / kStallCurrent / 2 + 0.03) / (0.93 * 0.93);
+  // Motor velocity constant
+  static constexpr double Kv =
+      ((kFreeSpeed / 60.0 * 2.0 * M_PI) / (12.0 - kR * kFreeCurrent));
+  // Torque constant
+  static constexpr double Kt = kStallTorque / kStallCurrent;
+
+  PolyDrivetrain()
+      : U_Poly_((Eigen::Matrix<double, 4, 2>() << /*[[*/ 1, 0 /*]*/,
+                 /*[*/ -1, 0 /*]*/,
+                 /*[*/ 0, 1 /*]*/,
+                 /*[*/ 0, -1 /*]]*/).finished(),
+                (Eigen::Matrix<double, 4, 1>() << /*[[*/ 12 /*]*/,
+                 /*[*/ 12 /*]*/,
+                 /*[*/ 12 /*]*/,
+                 /*[*/ 12 /*]]*/).finished()),
+        loop_(new StateFeedbackLoop<2, 2, 2>(
+            constants::GetValues().make_v_drivetrain_loop())),
+        ttrust_(1.1),
+        wheel_(0.0),
+        throttle_(0.0),
+        quickturn_(false),
+        stale_count_(0),
+        position_time_delta_(0.01),
+        left_gear_(LOW),
+        right_gear_(LOW),
+        counter_(0) {
+
+    last_position_.Zero();
+    position_.Zero();
+  }
+  static bool IsInGear(Gear gear) { return gear == LOW || gear == HIGH; }
+
+  static double MotorSpeed(const constants::ShifterHallEffect &hall_effect,
+                           double shifter_position, double velocity) {
+    // TODO(austin): G_high, G_low and kWheelRadius
+    const double avg_hall_effect =
+        (hall_effect.clear_high + hall_effect.clear_low) / 2.0;
+
+    if (shifter_position > avg_hall_effect) {
+      return velocity / constants::GetValues().high_gear_ratio / kWheelRadius;
+    } else {
+      return velocity / constants::GetValues().low_gear_ratio / kWheelRadius;
+    }
+  }
+
+  Gear ComputeGear(const constants::ShifterHallEffect &hall_effect,
+                   double velocity, Gear current) {
+    const double low_omega = MotorSpeed(hall_effect, 0.0, ::std::abs(velocity));
+    const double high_omega =
+        MotorSpeed(hall_effect, 1.0, ::std::abs(velocity));
+
+    double high_torque = ((12.0 - high_omega / Kv) * Kt / kR);
+    double low_torque = ((12.0 - low_omega / Kv) * Kt / kR);
+    double high_power = high_torque * high_omega;
+    double low_power = low_torque * low_omega;
+
+    // TODO(aschuh): Do this right!
+    if ((current == HIGH || high_power > low_power + 160) &&
+        ::std::abs(velocity) > 0.14) {
+      return HIGH;
+    } else {
+      return LOW;
+    }
+  }
+
+  void SetGoal(double wheel, double throttle, bool quickturn, bool highgear) {
+    const double kWheelNonLinearity = 0.5;
+    // Apply a sin function that's scaled to make it feel better.
+    const double angular_range = M_PI_2 * kWheelNonLinearity;
+
+    wheel_ = sin(angular_range * wheel) / sin(angular_range);
+    wheel_ = sin(angular_range * wheel_) / sin(angular_range);
+    wheel_ *= 2.3;
+    quickturn_ = quickturn;
+
+    static const double kThrottleDeadband = 0.05;
+    if (::std::abs(throttle) < kThrottleDeadband) {
+      throttle_ = 0;
+    } else {
+      throttle_ = copysign((::std::abs(throttle) - kThrottleDeadband) /
+                           (1.0 - kThrottleDeadband), throttle);
+    }
+
+    // TODO(austin): Fix the upshift logic to include states.
+    Gear requested_gear;
+    if (false) {
+      const auto &values = constants::GetValues();
+      const double current_left_velocity =
+          (position_.left_encoder - last_position_.left_encoder) /
+          position_time_delta_;
+      const double current_right_velocity =
+          (position_.right_encoder - last_position_.right_encoder) /
+          position_time_delta_;
+
+      Gear left_requested =
+          ComputeGear(values.left_drive, current_left_velocity, left_gear_);
+      Gear right_requested =
+          ComputeGear(values.right_drive, current_right_velocity, right_gear_);
+      requested_gear =
+          (left_requested == HIGH || right_requested == HIGH) ? HIGH : LOW;
+    } else {
+      requested_gear = highgear ? HIGH : LOW;
+    }
+
+    const Gear shift_up =
+        constants::GetValues().clutch_transmission ? HIGH : SHIFTING_UP;
+    const Gear shift_down =
+        constants::GetValues().clutch_transmission ? LOW : SHIFTING_DOWN;
+
+    if (left_gear_ != requested_gear) {
+      if (IsInGear(left_gear_)) {
+        if (requested_gear == HIGH) {
+          left_gear_ = shift_up;
+        } else {
+          left_gear_ = shift_down;
+        }
+      } else {
+        if (requested_gear == HIGH && left_gear_ == SHIFTING_DOWN) {
+          left_gear_ = SHIFTING_UP;
+        } else if (requested_gear == LOW && left_gear_ == SHIFTING_UP) {
+          left_gear_ = SHIFTING_DOWN;
+        }
+      }
+    }
+    if (right_gear_ != requested_gear) {
+      if (IsInGear(right_gear_)) {
+        if (requested_gear == HIGH) {
+          right_gear_ = shift_up;
+        } else {
+          right_gear_ = shift_down;
+        }
+      } else {
+        if (requested_gear == HIGH && right_gear_ == SHIFTING_DOWN) {
+          right_gear_ = SHIFTING_UP;
+        } else if (requested_gear == LOW && right_gear_ == SHIFTING_UP) {
+          right_gear_ = SHIFTING_DOWN;
+        }
+      }
+    }
+  }
+  void SetPosition(const DrivetrainQueue::Position *position) {
+    const auto &values = constants::GetValues();
+    if (position == NULL) {
+      ++stale_count_;
+    } else {
+      last_position_ = position_;
+      position_ = *position;
+      position_time_delta_ = (stale_count_ + 1) * 0.01;
+      stale_count_ = 0;
+    }
+
+#if HAVE_SHIFTERS
+    if (position) {
+      GearLogging gear_logging;
+      // Switch to the correct controller.
+      const double left_middle_shifter_position =
+          (values.left_drive.clear_high + values.left_drive.clear_low) / 2.0;
+      const double right_middle_shifter_position =
+          (values.right_drive.clear_high + values.right_drive.clear_low) / 2.0;
+
+      if (position->left_shifter_position < left_middle_shifter_position ||
+          left_gear_ == LOW) {
+        if (position->right_shifter_position < right_middle_shifter_position ||
+            right_gear_ == LOW) {
+          gear_logging.left_loop_high = false;
+          gear_logging.right_loop_high = false;
+          loop_->set_controller_index(gear_logging.controller_index = 0);
+        } else {
+          gear_logging.left_loop_high = false;
+          gear_logging.right_loop_high = true;
+          loop_->set_controller_index(gear_logging.controller_index = 1);
+        }
+      } else {
+        if (position->right_shifter_position < right_middle_shifter_position ||
+            right_gear_ == LOW) {
+          gear_logging.left_loop_high = true;
+          gear_logging.right_loop_high = false;
+          loop_->set_controller_index(gear_logging.controller_index = 2);
+        } else {
+          gear_logging.left_loop_high = true;
+          gear_logging.right_loop_high = true;
+          loop_->set_controller_index(gear_logging.controller_index = 3);
+        }
+      }
+
+      // TODO(austin): Constants.
+      if (position->left_shifter_position > values.left_drive.clear_high && left_gear_ == SHIFTING_UP) {
+        left_gear_ = HIGH;
+      }
+      if (position->left_shifter_position < values.left_drive.clear_low && left_gear_ == SHIFTING_DOWN) {
+        left_gear_ = LOW;
+      }
+      if (position->right_shifter_position > values.right_drive.clear_high && right_gear_ == SHIFTING_UP) {
+        right_gear_ = HIGH;
+      }
+      if (position->right_shifter_position < values.right_drive.clear_low && right_gear_ == SHIFTING_DOWN) {
+        right_gear_ = LOW;
+      }
+
+      gear_logging.left_state = left_gear_;
+      gear_logging.right_state = right_gear_;
+      LOG_STRUCT(DEBUG, "state", gear_logging);
+    }
+#else
+    (void) values;
+#endif
+  }
+
+  double FilterVelocity(double throttle) {
+    const Eigen::Matrix<double, 2, 2> FF =
+        loop_->B().inverse() *
+        (Eigen::Matrix<double, 2, 2>::Identity() - loop_->A());
+
+    constexpr int kHighGearController = 3;
+    const Eigen::Matrix<double, 2, 2> FF_high =
+        loop_->controller(kHighGearController).plant.B().inverse() *
+        (Eigen::Matrix<double, 2, 2>::Identity() -
+         loop_->controller(kHighGearController).plant.A());
+
+    ::Eigen::Matrix<double, 1, 2> FF_sum = FF.colwise().sum();
+    int min_FF_sum_index;
+    const double min_FF_sum = FF_sum.minCoeff(&min_FF_sum_index);
+    const double min_K_sum = loop_->K().col(min_FF_sum_index).sum();
+    const double high_min_FF_sum = FF_high.col(0).sum();
+
+    const double adjusted_ff_voltage = ::aos::Clip(
+        throttle * 12.0 * min_FF_sum / high_min_FF_sum, -12.0, 12.0);
+    return (adjusted_ff_voltage +
+            ttrust_ * min_K_sum * (loop_->X_hat(0, 0) + loop_->X_hat(1, 0)) /
+                2.0) /
+           (ttrust_ * min_K_sum + min_FF_sum);
+  }
+
+  double MaxVelocity() {
+    const Eigen::Matrix<double, 2, 2> FF =
+        loop_->B().inverse() *
+        (Eigen::Matrix<double, 2, 2>::Identity() - loop_->A());
+
+    constexpr int kHighGearController = 3;
+    const Eigen::Matrix<double, 2, 2> FF_high =
+        loop_->controller(kHighGearController).plant.B().inverse() *
+        (Eigen::Matrix<double, 2, 2>::Identity() -
+         loop_->controller(kHighGearController).plant.A());
+
+    ::Eigen::Matrix<double, 1, 2> FF_sum = FF.colwise().sum();
+    int min_FF_sum_index;
+    const double min_FF_sum = FF_sum.minCoeff(&min_FF_sum_index);
+    //const double min_K_sum = loop_->K().col(min_FF_sum_index).sum();
+    const double high_min_FF_sum = FF_high.col(0).sum();
+
+    const double adjusted_ff_voltage = ::aos::Clip(
+        12.0 * min_FF_sum / high_min_FF_sum, -12.0, 12.0);
+    return adjusted_ff_voltage / min_FF_sum;
+  }
+
+  void Update() {
+    const auto &values = constants::GetValues();
+    // TODO(austin): Observer for the current velocity instead of difference
+    // calculations.
+    ++counter_;
+#if HAVE_SHIFTERS
+    const double current_left_velocity =
+        (position_.left_encoder - last_position_.left_encoder) /
+        position_time_delta_;
+    const double current_right_velocity =
+        (position_.right_encoder - last_position_.right_encoder) /
+        position_time_delta_;
+    const double left_motor_speed =
+        MotorSpeed(values.left_drive, position_.left_shifter_position,
+                   current_left_velocity);
+    const double right_motor_speed =
+        MotorSpeed(values.right_drive, position_.right_shifter_position,
+                   current_right_velocity);
+
+    {
+      CIMLogging logging;
+
+      // Reset the CIM model to the current conditions to be ready for when we
+      // shift.
+      if (IsInGear(left_gear_)) {
+        logging.left_in_gear = true;
+      } else {
+        logging.left_in_gear = false;
+      }
+      logging.left_motor_speed = left_motor_speed;
+      logging.left_velocity = current_left_velocity;
+      if (IsInGear(right_gear_)) {
+        logging.right_in_gear = true;
+      } else {
+        logging.right_in_gear = false;
+      }
+      logging.right_motor_speed = right_motor_speed;
+      logging.right_velocity = current_right_velocity;
+
+      LOG_STRUCT(DEBUG, "currently", logging);
+    }
+#else
+    (void) values;
+#endif
+
+#if HAVE_SHIFTERS
+    if (IsInGear(left_gear_) && IsInGear(right_gear_)) {
+#else
+    {
+#endif
+      // FF * X = U (steady state)
+      const Eigen::Matrix<double, 2, 2> FF =
+          loop_->B().inverse() *
+          (Eigen::Matrix<double, 2, 2>::Identity() - loop_->A());
+
+      // Invert the plant to figure out how the velocity filter would have to
+      // work
+      // out in order to filter out the forwards negative inertia.
+      // This math assumes that the left and right power and velocity are
+      // equals,
+      // and that the plant is the same on the left and right.
+      const double fvel = FilterVelocity(throttle_);
+
+      const double sign_svel = wheel_ * ((fvel > 0.0) ? 1.0 : -1.0);
+      double steering_velocity;
+      if (quickturn_) {
+        steering_velocity = wheel_ * MaxVelocity();
+      } else {
+        steering_velocity = ::std::abs(fvel) * wheel_;
+      }
+      const double left_velocity = fvel - steering_velocity;
+      const double right_velocity = fvel + steering_velocity;
+      LOG(DEBUG, "l=%f r=%f\n", left_velocity, right_velocity);
+
+      // Integrate velocity to get the position.
+      // This position is used to get integral control.
+      loop_->mutable_R() << left_velocity, right_velocity;
+
+      if (!quickturn_) {
+        // K * R = w
+        Eigen::Matrix<double, 1, 2> equality_k;
+        equality_k << 1 + sign_svel, -(1 - sign_svel);
+        const double equality_w = 0.0;
+
+        // Construct a constraint on R by manipulating the constraint on U
+        ::aos::controls::HPolytope<2> R_poly = ::aos::controls::HPolytope<2>(
+            U_Poly_.H() * (loop_->K() + FF),
+            U_Poly_.k() + U_Poly_.H() * loop_->K() * loop_->X_hat());
+
+        // Limit R back inside the box.
+        loop_->mutable_R() =
+            CoerceGoal(R_poly, equality_k, equality_w, loop_->R());
+      }
+
+      const Eigen::Matrix<double, 2, 1> FF_volts = FF * loop_->R();
+      const Eigen::Matrix<double, 2, 1> U_ideal =
+          loop_->K() * (loop_->R() - loop_->X_hat()) + FF_volts;
+
+      for (int i = 0; i < 2; i++) {
+        loop_->mutable_U()[i] = ::aos::Clip(U_ideal[i], -12, 12);
+      }
+
+      // TODO(austin): Model this better.
+      // TODO(austin): Feed back?
+      loop_->mutable_X_hat() =
+          loop_->A() * loop_->X_hat() + loop_->B() * loop_->U();
+#if HAVE_SHIFTERS
+    } else {
+      // Any motor is not in gear.  Speed match.
+      ::Eigen::Matrix<double, 1, 1> R_left;
+      ::Eigen::Matrix<double, 1, 1> R_right;
+      R_left(0, 0) = left_motor_speed;
+      R_right(0, 0) = right_motor_speed;
+
+      const double wiggle =
+          (static_cast<double>((counter_ % 20) / 10) - 0.5) * 5.0;
+
+      loop_->mutable_U(0, 0) = ::aos::Clip(
+          (R_left / Kv)(0, 0) + (IsInGear(left_gear_) ? 0 : wiggle),
+          -12.0, 12.0);
+      loop_->mutable_U(1, 0) = ::aos::Clip(
+          (R_right / Kv)(0, 0) + (IsInGear(right_gear_) ? 0 : wiggle),
+          -12.0, 12.0);
+      loop_->mutable_U() *= 12.0 / ::aos::robot_state->voltage_battery;
+#endif
+    }
+  }
+
+  void SendMotors(DrivetrainQueue::Output *output) {
+    if (output != NULL) {
+      output->left_voltage = loop_->U(0, 0);
+      output->right_voltage = loop_->U(1, 0);
+      output->left_high = left_gear_ == HIGH || left_gear_ == SHIFTING_UP;
+      output->right_high = right_gear_ == HIGH || right_gear_ == SHIFTING_UP;
+    }
+  }
+
+ private:
+  const ::aos::controls::HPolytope<2> U_Poly_;
+
+  ::std::unique_ptr<StateFeedbackLoop<2, 2, 2>> loop_;
+
+  const double ttrust_;
+  double wheel_;
+  double throttle_;
+  bool quickturn_;
+  int stale_count_;
+  double position_time_delta_;
+  Gear left_gear_;
+  Gear right_gear_;
+  DrivetrainQueue::Position last_position_;
+  DrivetrainQueue::Position position_;
+  int counter_;
+};
+constexpr double PolyDrivetrain::kStallTorque;
+constexpr double PolyDrivetrain::kStallCurrent;
+constexpr double PolyDrivetrain::kFreeSpeed;
+constexpr double PolyDrivetrain::kFreeCurrent;
+constexpr double PolyDrivetrain::J;
+constexpr double PolyDrivetrain::m;
+constexpr double PolyDrivetrain::rb;
+constexpr double PolyDrivetrain::kWheelRadius;
+constexpr double PolyDrivetrain::kR;
+constexpr double PolyDrivetrain::Kv;
+constexpr double PolyDrivetrain::Kt;
+
+
+void DrivetrainLoop::RunIteration(const DrivetrainQueue::Goal *goal,
+                                  const DrivetrainQueue::Position *position,
+                                  DrivetrainQueue::Output *output,
+                                  DrivetrainQueue::Status * status) {
+  // TODO(aschuh): These should be members of the class.
+  static DrivetrainMotorsSS dt_closedloop;
+  static PolyDrivetrain dt_openloop;
+
+  bool bad_pos = false;
+  if (position == nullptr) {
+    LOG_INTERVAL(no_position_);
+    bad_pos = true;
+  }
+  no_position_.Print();
+
+  bool control_loop_driving = false;
+  if (goal) {
+    double wheel = goal->steering;
+    double throttle = goal->throttle;
+    bool quickturn = goal->quickturn;
+#if HAVE_SHIFTERS
+    bool highgear = goal->highgear;
+#endif
+
+    control_loop_driving = goal->control_loop_driving;
+    double left_goal = goal->left_goal;
+    double right_goal = goal->right_goal;
+
+    dt_closedloop.SetGoal(left_goal, goal->left_velocity_goal, right_goal,
+                          goal->right_velocity_goal);
+#if HAVE_SHIFTERS
+    dt_openloop.SetGoal(wheel, throttle, quickturn, highgear);
+#else
+    dt_openloop.SetGoal(wheel, throttle, quickturn, false);
+#endif
+  }
+
+  if (!bad_pos) {
+    const double left_encoder = position->left_encoder;
+    const double right_encoder = position->right_encoder;
+    if (gyro_reading.FetchLatest()) {
+      LOG_STRUCT(DEBUG, "using", *gyro_reading.get());
+      dt_closedloop.SetPosition(left_encoder, right_encoder,
+                                gyro_reading->angle);
+    } else {
+      dt_closedloop.SetRawPosition(left_encoder, right_encoder);
+    }
+  }
+  dt_openloop.SetPosition(position);
+  dt_openloop.Update();
+
+  if (control_loop_driving) {
+    dt_closedloop.Update(output == NULL, true);
+    dt_closedloop.SendMotors(output);
+  } else {
+    dt_openloop.SendMotors(output);
+    if (output) {
+      dt_closedloop.SetExternalMotors(output->left_voltage,
+                                      output->right_voltage);
+    }
+    dt_closedloop.Update(output == NULL, false);
+  }
+
+  // set the output status of the control loop state
+  if (status) {
+    bool done = false;
+    if (goal) {
+      done = ((::std::abs(goal->left_goal -
+                          dt_closedloop.GetEstimatedLeftEncoder()) <
+               constants::GetValues().drivetrain_done_distance) &&
+              (::std::abs(goal->right_goal -
+                          dt_closedloop.GetEstimatedRightEncoder()) <
+               constants::GetValues().drivetrain_done_distance));
+    }
+    status->is_done = done;
+    status->robot_speed = dt_closedloop.GetEstimatedRobotSpeed();
+    status->filtered_left_position = dt_closedloop.GetEstimatedLeftEncoder();
+    status->filtered_right_position = dt_closedloop.GetEstimatedRightEncoder();
+
+    status->filtered_left_velocity = dt_closedloop.loop().X_hat(1, 0);
+    status->filtered_right_velocity = dt_closedloop.loop().X_hat(3, 0);
+    status->output_was_capped = dt_closedloop.OutputWasCapped();
+    status->uncapped_left_voltage = dt_closedloop.loop().U_uncapped(0, 0);
+    status->uncapped_right_voltage = dt_closedloop.loop().U_uncapped(1, 0);
+  }
+}
+
+}  // namespace control_loops
+}  // namespace frc971
diff --git a/y2015/control_loops/drivetrain/drivetrain.gyp b/y2015/control_loops/drivetrain/drivetrain.gyp
new file mode 100644
index 0000000..4333258
--- /dev/null
+++ b/y2015/control_loops/drivetrain/drivetrain.gyp
@@ -0,0 +1,103 @@
+{
+  'targets': [
+    {
+      'target_name': 'replay_drivetrain',
+      'type': 'executable',
+      'variables': {
+        'no_rsync': 1,
+      },
+      'sources': [
+        'replay_drivetrain.cc',
+      ],
+      'dependencies': [
+        'drivetrain_queue',
+        '<(AOS)/common/controls/controls.gyp:replay_control_loop',
+        '<(AOS)/linux_code/linux_code.gyp:init',
+      ],
+    },
+    {
+      'target_name': 'drivetrain_queue',
+      'type': 'static_library',
+      'sources': ['drivetrain.q'],
+      'variables': {
+        'header_path': 'y2015/control_loops/drivetrain',
+      },
+      'dependencies': [
+        '<(AOS)/common/controls/controls.gyp:control_loop_queues',
+      ],
+      'export_dependent_settings': [
+        '<(AOS)/common/controls/controls.gyp:control_loop_queues',
+      ],
+      'includes': ['../../../aos/build/queues.gypi'],
+    },
+    {
+      'target_name': 'polydrivetrain_plants',
+      'type': 'static_library',
+      'sources': [
+        'polydrivetrain_dog_motor_plant.cc',
+        'drivetrain_dog_motor_plant.cc',
+      ],
+      'dependencies': [
+        '<(DEPTH)/frc971/control_loops/control_loops.gyp:state_feedback_loop',
+      ],
+      'export_dependent_settings': [
+        '<(DEPTH)/frc971/control_loops/control_loops.gyp:state_feedback_loop',
+      ],
+    },
+    {
+      'target_name': 'drivetrain_lib',
+      'type': 'static_library',
+      'sources': [
+        'drivetrain.cc',
+        'polydrivetrain_cim_plant.cc',
+      ],
+      'dependencies': [
+        'drivetrain_queue',
+        '<(AOS)/common/controls/controls.gyp:control_loop',
+        '<(DEPTH)/y2015/y2015.gyp:constants',
+        '<(AOS)/common/controls/controls.gyp:polytope',
+        '<(DEPTH)/frc971/control_loops/control_loops.gyp:state_feedback_loop',
+        '<(DEPTH)/frc971/control_loops/control_loops.gyp:coerce_goal',
+        '<(DEPTH)/frc971/queues/queues.gyp:gyro',
+        '<(AOS)/common/util/util.gyp:log_interval',
+        '<(AOS)/common/logging/logging.gyp:queue_logging',
+        '<(AOS)/common/logging/logging.gyp:matrix_logging',
+      ],
+      'export_dependent_settings': [
+        '<(AOS)/common/controls/controls.gyp:polytope',
+        '<(DEPTH)/frc971/control_loops/control_loops.gyp:state_feedback_loop',
+        '<(DEPTH)/frc971/control_loops/control_loops.gyp:coerce_goal',
+        '<(AOS)/common/controls/controls.gyp:control_loop',
+        'drivetrain_queue',
+      ],
+    },
+    {
+      'target_name': 'drivetrain_lib_test',
+      'type': 'executable',
+      'sources': [
+        'drivetrain_lib_test.cc',
+      ],
+      'dependencies': [
+        '<(EXTERNALS):gtest',
+        'drivetrain_queue',
+        'drivetrain_lib',
+        '<(AOS)/common/controls/controls.gyp:control_loop_test',
+        '<(DEPTH)/frc971/control_loops/control_loops.gyp:state_feedback_loop',
+        '<(DEPTH)/frc971/queues/queues.gyp:gyro',
+        '<(AOS)/common/common.gyp:queues',
+      ],
+    },
+    {
+      'target_name': 'drivetrain',
+      'type': 'executable',
+      'sources': [
+        'drivetrain_main.cc',
+      ],
+      'dependencies': [
+        '<(AOS)/linux_code/linux_code.gyp:init',
+        'drivetrain_lib',
+        'drivetrain_queue',
+      ],
+    },
+  ],
+}
diff --git a/y2015/control_loops/drivetrain/drivetrain.h b/y2015/control_loops/drivetrain/drivetrain.h
new file mode 100644
index 0000000..8e8768e
--- /dev/null
+++ b/y2015/control_loops/drivetrain/drivetrain.h
@@ -0,0 +1,43 @@
+#ifndef Y2015_CONTROL_LOOPS_DRIVETRAIN_H_
+#define Y2015_CONTROL_LOOPS_DRIVETRAIN_H_
+
+#include "Eigen/Dense"
+
+#include "aos/common/controls/polytope.h"
+#include "aos/common/controls/control_loop.h"
+#include "aos/common/controls/polytope.h"
+#include "y2015/control_loops/drivetrain/drivetrain.q.h"
+#include "aos/common/util/log_interval.h"
+
+namespace frc971 {
+namespace control_loops {
+
+class DrivetrainLoop
+    : public aos::controls::ControlLoop<control_loops::DrivetrainQueue> {
+ public:
+  // Constructs a control loop which can take a Drivetrain or defaults to the
+  // drivetrain at frc971::control_loops::drivetrain
+  explicit DrivetrainLoop(control_loops::DrivetrainQueue *my_drivetrain =
+                              &control_loops::drivetrain_queue)
+      : aos::controls::ControlLoop<control_loops::DrivetrainQueue>(
+            my_drivetrain) {
+    ::aos::controls::HPolytope<0>::Init();
+  }
+
+ protected:
+  // Executes one cycle of the control loop.
+  virtual void RunIteration(
+      const control_loops::DrivetrainQueue::Goal *goal,
+      const control_loops::DrivetrainQueue::Position *position,
+      control_loops::DrivetrainQueue::Output *output,
+      control_loops::DrivetrainQueue::Status *status);
+
+  typedef ::aos::util::SimpleLogInterval SimpleLogInterval;
+  SimpleLogInterval no_position_ = SimpleLogInterval(
+      ::aos::time::Time::InSeconds(0.25), WARNING, "no position");
+};
+
+}  // namespace control_loops
+}  // namespace frc971
+
+#endif  // Y2015_CONTROL_LOOPS_DRIVETRAIN_H_
diff --git a/y2015/control_loops/drivetrain/drivetrain.q b/y2015/control_loops/drivetrain/drivetrain.q
new file mode 100644
index 0000000..942c5b3
--- /dev/null
+++ b/y2015/control_loops/drivetrain/drivetrain.q
@@ -0,0 +1,71 @@
+package frc971.control_loops;
+
+import "aos/common/controls/control_loops.q";
+
+struct GearLogging {
+  int8_t controller_index;
+  bool left_loop_high;
+  bool right_loop_high;
+  int8_t left_state;
+  int8_t right_state;
+};
+
+struct CIMLogging {
+  bool left_in_gear;
+  bool right_in_gear;
+  double left_motor_speed;
+  double right_motor_speed;
+  double left_velocity;
+  double right_velocity;
+};
+
+queue_group DrivetrainQueue {
+  implements aos.control_loops.ControlLoop;
+
+  message Goal {
+    double steering;
+    double throttle;
+    //bool highgear;
+    bool quickturn;
+    bool control_loop_driving;
+    double left_goal;
+    double left_velocity_goal;
+    double right_goal;
+    double right_velocity_goal;
+  };
+
+  message Position {
+    double left_encoder;
+    double right_encoder;
+    //double left_shifter_position;
+    //double right_shifter_position;
+  };
+
+  message Output {
+    double left_voltage;
+    double right_voltage;
+    bool left_high;
+    bool right_high;
+  };
+
+  message Status {
+    double robot_speed;
+    double filtered_left_position;
+    double filtered_right_position;
+    double filtered_left_velocity;
+    double filtered_right_velocity;
+
+    double uncapped_left_voltage;
+    double uncapped_right_voltage;
+    bool output_was_capped;
+
+    bool is_done;
+  };
+
+  queue Goal goal;
+  queue Position position;
+  queue Output output;
+  queue Status status;
+};
+
+queue_group DrivetrainQueue drivetrain_queue;
diff --git a/y2015/control_loops/drivetrain/drivetrain_dog_motor_plant.cc b/y2015/control_loops/drivetrain/drivetrain_dog_motor_plant.cc
new file mode 100644
index 0000000..e2f5a9a
--- /dev/null
+++ b/y2015/control_loops/drivetrain/drivetrain_dog_motor_plant.cc
@@ -0,0 +1,133 @@
+#include "y2015/control_loops/drivetrain/drivetrain_dog_motor_plant.h"
+
+#include <vector>
+
+#include "frc971/control_loops/state_feedback_loop.h"
+
+namespace frc971 {
+namespace control_loops {
+
+StateFeedbackPlantCoefficients<4, 2, 2> MakeDrivetrainLowLowPlantCoefficients() {
+  Eigen::Matrix<double, 4, 4> A;
+  A << 1.0, 0.00494348612824, 0.0, 1.24048455404e-05, 0.0, 0.977484092703, 0.0, 0.00492433284048, 0.0, 1.24048455404e-05, 1.0, 0.00494348612824, 0.0, 0.00492433284048, 0.0, 0.977484092703;
+  Eigen::Matrix<double, 4, 2> B;
+  B << 2.09180756177e-05, -4.59153636043e-06, 0.00833405032795, -0.00182269526971, -4.59153636043e-06, 2.09180756177e-05, -0.00182269526971, 0.00833405032795;
+  Eigen::Matrix<double, 2, 4> C;
+  C << 1, 0, 0, 0, 0, 0, 1, 0;
+  Eigen::Matrix<double, 2, 2> D;
+  D << 0, 0, 0, 0;
+  Eigen::Matrix<double, 2, 1> U_max;
+  U_max << 12.0, 12.0;
+  Eigen::Matrix<double, 2, 1> U_min;
+  U_min << -12.0, -12.0;
+  return StateFeedbackPlantCoefficients<4, 2, 2>(A, B, C, D, U_max, U_min);
+}
+
+StateFeedbackPlantCoefficients<4, 2, 2> MakeDrivetrainLowHighPlantCoefficients() {
+  Eigen::Matrix<double, 4, 4> A;
+  A << 1.0, 0.00494348612824, 0.0, 1.24048455404e-05, 0.0, 0.977484092703, 0.0, 0.00492433284048, 0.0, 1.24048455404e-05, 1.0, 0.00494348612824, 0.0, 0.00492433284048, 0.0, 0.977484092703;
+  Eigen::Matrix<double, 4, 2> B;
+  B << 2.09180756177e-05, -4.59153636043e-06, 0.00833405032795, -0.00182269526971, -4.59153636043e-06, 2.09180756177e-05, -0.00182269526971, 0.00833405032795;
+  Eigen::Matrix<double, 2, 4> C;
+  C << 1, 0, 0, 0, 0, 0, 1, 0;
+  Eigen::Matrix<double, 2, 2> D;
+  D << 0, 0, 0, 0;
+  Eigen::Matrix<double, 2, 1> U_max;
+  U_max << 12.0, 12.0;
+  Eigen::Matrix<double, 2, 1> U_min;
+  U_min << -12.0, -12.0;
+  return StateFeedbackPlantCoefficients<4, 2, 2>(A, B, C, D, U_max, U_min);
+}
+
+StateFeedbackPlantCoefficients<4, 2, 2> MakeDrivetrainHighLowPlantCoefficients() {
+  Eigen::Matrix<double, 4, 4> A;
+  A << 1.0, 0.00494348612824, 0.0, 1.24048455404e-05, 0.0, 0.977484092703, 0.0, 0.00492433284048, 0.0, 1.24048455404e-05, 1.0, 0.00494348612824, 0.0, 0.00492433284048, 0.0, 0.977484092703;
+  Eigen::Matrix<double, 4, 2> B;
+  B << 2.09180756177e-05, -4.59153636043e-06, 0.00833405032795, -0.00182269526971, -4.59153636043e-06, 2.09180756177e-05, -0.00182269526971, 0.00833405032795;
+  Eigen::Matrix<double, 2, 4> C;
+  C << 1, 0, 0, 0, 0, 0, 1, 0;
+  Eigen::Matrix<double, 2, 2> D;
+  D << 0, 0, 0, 0;
+  Eigen::Matrix<double, 2, 1> U_max;
+  U_max << 12.0, 12.0;
+  Eigen::Matrix<double, 2, 1> U_min;
+  U_min << -12.0, -12.0;
+  return StateFeedbackPlantCoefficients<4, 2, 2>(A, B, C, D, U_max, U_min);
+}
+
+StateFeedbackPlantCoefficients<4, 2, 2> MakeDrivetrainHighHighPlantCoefficients() {
+  Eigen::Matrix<double, 4, 4> A;
+  A << 1.0, 0.00494348612824, 0.0, 1.24048455404e-05, 0.0, 0.977484092703, 0.0, 0.00492433284048, 0.0, 1.24048455404e-05, 1.0, 0.00494348612824, 0.0, 0.00492433284048, 0.0, 0.977484092703;
+  Eigen::Matrix<double, 4, 2> B;
+  B << 2.09180756177e-05, -4.59153636043e-06, 0.00833405032795, -0.00182269526971, -4.59153636043e-06, 2.09180756177e-05, -0.00182269526971, 0.00833405032795;
+  Eigen::Matrix<double, 2, 4> C;
+  C << 1, 0, 0, 0, 0, 0, 1, 0;
+  Eigen::Matrix<double, 2, 2> D;
+  D << 0, 0, 0, 0;
+  Eigen::Matrix<double, 2, 1> U_max;
+  U_max << 12.0, 12.0;
+  Eigen::Matrix<double, 2, 1> U_min;
+  U_min << -12.0, -12.0;
+  return StateFeedbackPlantCoefficients<4, 2, 2>(A, B, C, D, U_max, U_min);
+}
+
+StateFeedbackController<4, 2, 2> MakeDrivetrainLowLowController() {
+  Eigen::Matrix<double, 4, 2> L;
+  L << 1.2774840927, 0.00492433284048, 79.1440456622, 1.05150722636, 0.00492433284048, 1.2774840927, 1.05150722636, 79.1440456622;
+  Eigen::Matrix<double, 2, 4> K;
+  K << 160.19677247, 15.5358468938, 1.60401194139, 1.33861213093, 1.60401194142, 1.33861213094, 160.19677247, 15.5358468938;
+  Eigen::Matrix<double, 4, 4> A_inv;
+  A_inv << 1.0, -0.00505742153256, 0.0, 1.27875036472e-05, 0.0, 1.02306051542, 0.0, -0.00515393603998, 0.0, 1.27875036472e-05, 1.0, -0.00505742153256, 0.0, -0.00515393603998, 0.0, 1.02306051542;
+  return StateFeedbackController<4, 2, 2>(L, K, A_inv, MakeDrivetrainLowLowPlantCoefficients());
+}
+
+StateFeedbackController<4, 2, 2> MakeDrivetrainLowHighController() {
+  Eigen::Matrix<double, 4, 2> L;
+  L << 1.2774840927, 0.00492433284048, 79.1440456622, 1.05150722636, 0.00492433284048, 1.2774840927, 1.05150722636, 79.1440456622;
+  Eigen::Matrix<double, 2, 4> K;
+  K << 160.19677247, 15.5358468938, 1.60401194139, 1.33861213093, 1.60401194142, 1.33861213094, 160.19677247, 15.5358468938;
+  Eigen::Matrix<double, 4, 4> A_inv;
+  A_inv << 1.0, -0.00505742153256, 0.0, 1.27875036472e-05, 0.0, 1.02306051542, 0.0, -0.00515393603998, 0.0, 1.27875036472e-05, 1.0, -0.00505742153256, 0.0, -0.00515393603998, 0.0, 1.02306051542;
+  return StateFeedbackController<4, 2, 2>(L, K, A_inv, MakeDrivetrainLowHighPlantCoefficients());
+}
+
+StateFeedbackController<4, 2, 2> MakeDrivetrainHighLowController() {
+  Eigen::Matrix<double, 4, 2> L;
+  L << 1.2774840927, 0.00492433284048, 79.1440456622, 1.05150722636, 0.00492433284048, 1.2774840927, 1.05150722636, 79.1440456622;
+  Eigen::Matrix<double, 2, 4> K;
+  K << 160.19677247, 15.5358468938, 1.60401194139, 1.33861213093, 1.60401194142, 1.33861213094, 160.19677247, 15.5358468938;
+  Eigen::Matrix<double, 4, 4> A_inv;
+  A_inv << 1.0, -0.00505742153256, 0.0, 1.27875036472e-05, 0.0, 1.02306051542, 0.0, -0.00515393603998, 0.0, 1.27875036472e-05, 1.0, -0.00505742153256, 0.0, -0.00515393603998, 0.0, 1.02306051542;
+  return StateFeedbackController<4, 2, 2>(L, K, A_inv, MakeDrivetrainHighLowPlantCoefficients());
+}
+
+StateFeedbackController<4, 2, 2> MakeDrivetrainHighHighController() {
+  Eigen::Matrix<double, 4, 2> L;
+  L << 1.2774840927, 0.00492433284048, 79.1440456622, 1.05150722636, 0.00492433284048, 1.2774840927, 1.05150722636, 79.1440456622;
+  Eigen::Matrix<double, 2, 4> K;
+  K << 160.19677247, 15.5358468938, 1.60401194139, 1.33861213093, 1.60401194142, 1.33861213094, 160.19677247, 15.5358468938;
+  Eigen::Matrix<double, 4, 4> A_inv;
+  A_inv << 1.0, -0.00505742153256, 0.0, 1.27875036472e-05, 0.0, 1.02306051542, 0.0, -0.00515393603998, 0.0, 1.27875036472e-05, 1.0, -0.00505742153256, 0.0, -0.00515393603998, 0.0, 1.02306051542;
+  return StateFeedbackController<4, 2, 2>(L, K, A_inv, MakeDrivetrainHighHighPlantCoefficients());
+}
+
+StateFeedbackPlant<4, 2, 2> MakeDrivetrainPlant() {
+  ::std::vector< ::std::unique_ptr<StateFeedbackPlantCoefficients<4, 2, 2>>> plants(4);
+  plants[0] = ::std::unique_ptr<StateFeedbackPlantCoefficients<4, 2, 2>>(new StateFeedbackPlantCoefficients<4, 2, 2>(MakeDrivetrainLowLowPlantCoefficients()));
+  plants[1] = ::std::unique_ptr<StateFeedbackPlantCoefficients<4, 2, 2>>(new StateFeedbackPlantCoefficients<4, 2, 2>(MakeDrivetrainLowHighPlantCoefficients()));
+  plants[2] = ::std::unique_ptr<StateFeedbackPlantCoefficients<4, 2, 2>>(new StateFeedbackPlantCoefficients<4, 2, 2>(MakeDrivetrainHighLowPlantCoefficients()));
+  plants[3] = ::std::unique_ptr<StateFeedbackPlantCoefficients<4, 2, 2>>(new StateFeedbackPlantCoefficients<4, 2, 2>(MakeDrivetrainHighHighPlantCoefficients()));
+  return StateFeedbackPlant<4, 2, 2>(&plants);
+}
+
+StateFeedbackLoop<4, 2, 2> MakeDrivetrainLoop() {
+  ::std::vector< ::std::unique_ptr<StateFeedbackController<4, 2, 2>>> controllers(4);
+  controllers[0] = ::std::unique_ptr<StateFeedbackController<4, 2, 2>>(new StateFeedbackController<4, 2, 2>(MakeDrivetrainLowLowController()));
+  controllers[1] = ::std::unique_ptr<StateFeedbackController<4, 2, 2>>(new StateFeedbackController<4, 2, 2>(MakeDrivetrainLowHighController()));
+  controllers[2] = ::std::unique_ptr<StateFeedbackController<4, 2, 2>>(new StateFeedbackController<4, 2, 2>(MakeDrivetrainHighLowController()));
+  controllers[3] = ::std::unique_ptr<StateFeedbackController<4, 2, 2>>(new StateFeedbackController<4, 2, 2>(MakeDrivetrainHighHighController()));
+  return StateFeedbackLoop<4, 2, 2>(&controllers);
+}
+
+}  // namespace control_loops
+}  // namespace frc971
diff --git a/y2015/control_loops/drivetrain/drivetrain_dog_motor_plant.h b/y2015/control_loops/drivetrain/drivetrain_dog_motor_plant.h
new file mode 100644
index 0000000..a2848be
--- /dev/null
+++ b/y2015/control_loops/drivetrain/drivetrain_dog_motor_plant.h
@@ -0,0 +1,32 @@
+#ifndef Y2015_CONTROL_LOOPS_DRIVETRAIN_DRIVETRAIN_DOG_MOTOR_PLANT_H_
+#define Y2015_CONTROL_LOOPS_DRIVETRAIN_DRIVETRAIN_DOG_MOTOR_PLANT_H_
+
+#include "frc971/control_loops/state_feedback_loop.h"
+
+namespace frc971 {
+namespace control_loops {
+
+StateFeedbackPlantCoefficients<4, 2, 2> MakeDrivetrainLowLowPlantCoefficients();
+
+StateFeedbackController<4, 2, 2> MakeDrivetrainLowLowController();
+
+StateFeedbackPlantCoefficients<4, 2, 2> MakeDrivetrainLowHighPlantCoefficients();
+
+StateFeedbackController<4, 2, 2> MakeDrivetrainLowHighController();
+
+StateFeedbackPlantCoefficients<4, 2, 2> MakeDrivetrainHighLowPlantCoefficients();
+
+StateFeedbackController<4, 2, 2> MakeDrivetrainHighLowController();
+
+StateFeedbackPlantCoefficients<4, 2, 2> MakeDrivetrainHighHighPlantCoefficients();
+
+StateFeedbackController<4, 2, 2> MakeDrivetrainHighHighController();
+
+StateFeedbackPlant<4, 2, 2> MakeDrivetrainPlant();
+
+StateFeedbackLoop<4, 2, 2> MakeDrivetrainLoop();
+
+}  // namespace control_loops
+}  // namespace frc971
+
+#endif  // Y2015_CONTROL_LOOPS_DRIVETRAIN_DRIVETRAIN_DOG_MOTOR_PLANT_H_
diff --git a/y2015/control_loops/drivetrain/drivetrain_lib_test.cc b/y2015/control_loops/drivetrain/drivetrain_lib_test.cc
new file mode 100644
index 0000000..d3869aa
--- /dev/null
+++ b/y2015/control_loops/drivetrain/drivetrain_lib_test.cc
@@ -0,0 +1,297 @@
+#include <unistd.h>
+
+#include <memory>
+
+#include "gtest/gtest.h"
+#include "aos/common/network/team_number.h"
+#include "aos/common/queue_testutils.h"
+#include "aos/common/controls/polytope.h"
+#include "aos/common/controls/control_loop_test.h"
+
+#include "y2015/control_loops/drivetrain/drivetrain.q.h"
+#include "y2015/control_loops/drivetrain/drivetrain.h"
+#include "frc971/control_loops/state_feedback_loop.h"
+#include "frc971/control_loops/coerce_goal.h"
+#include "y2015/control_loops/drivetrain/drivetrain_dog_motor_plant.h"
+#include "frc971/queues/gyro.q.h"
+
+
+namespace frc971 {
+namespace control_loops {
+namespace testing {
+
+class Environment : public ::testing::Environment {
+ public:
+  virtual ~Environment() {}
+  // how to set up the environment.
+  virtual void SetUp() {
+    aos::controls::HPolytope<0>::Init();
+  }
+};
+::testing::Environment* const holder_env =
+  ::testing::AddGlobalTestEnvironment(new Environment);
+
+class TeamNumberEnvironment : public ::testing::Environment {
+ public:
+  // Override this to define how to set up the environment.
+  virtual void SetUp() { aos::network::OverrideTeamNumber(971); }
+};
+
+::testing::Environment* const team_number_env =
+    ::testing::AddGlobalTestEnvironment(new TeamNumberEnvironment);
+
+// Class which simulates the drivetrain and sends out queue messages containing
+// the position.
+class DrivetrainSimulation {
+ public:
+  // Constructs a motor simulation.
+  // TODO(aschuh) Do we want to test the clutch one too?
+  DrivetrainSimulation()
+      : drivetrain_plant_(
+            new StateFeedbackPlant<4, 2, 2>(MakeDrivetrainPlant())),
+        my_drivetrain_queue_(".frc971.control_loops.drivetrain",
+                       0x8a8dde77, ".frc971.control_loops.drivetrain.goal",
+                       ".frc971.control_loops.drivetrain.position",
+                       ".frc971.control_loops.drivetrain.output",
+                       ".frc971.control_loops.drivetrain.status") {
+    Reinitialize();
+  }
+
+  // Resets the plant.
+  void Reinitialize() {
+    drivetrain_plant_->mutable_X(0, 0) = 0.0;
+    drivetrain_plant_->mutable_X(1, 0) = 0.0;
+    drivetrain_plant_->mutable_Y() =
+        drivetrain_plant_->C() * drivetrain_plant_->X();
+    last_left_position_ = drivetrain_plant_->Y(0, 0);
+    last_right_position_ = drivetrain_plant_->Y(1, 0);
+  }
+
+  // Returns the position of the drivetrain.
+  double GetLeftPosition() const { return drivetrain_plant_->Y(0, 0); }
+  double GetRightPosition() const { return drivetrain_plant_->Y(1, 0); }
+
+  // Sends out the position queue messages.
+  void SendPositionMessage() {
+    const double left_encoder = GetLeftPosition();
+    const double right_encoder = GetRightPosition();
+
+    ::aos::ScopedMessagePtr<control_loops::DrivetrainQueue::Position> position =
+        my_drivetrain_queue_.position.MakeMessage();
+    position->left_encoder = left_encoder;
+    position->right_encoder = right_encoder;
+    position.Send();
+  }
+
+  // Simulates the drivetrain moving for one timestep.
+  void Simulate() {
+    last_left_position_ = drivetrain_plant_->Y(0, 0);
+    last_right_position_ = drivetrain_plant_->Y(1, 0);
+    EXPECT_TRUE(my_drivetrain_queue_.output.FetchLatest());
+    drivetrain_plant_->mutable_U() << my_drivetrain_queue_.output->left_voltage,
+        my_drivetrain_queue_.output->right_voltage;
+    drivetrain_plant_->Update();
+  }
+
+  ::std::unique_ptr<StateFeedbackPlant<4, 2, 2>> drivetrain_plant_;
+ private:
+  DrivetrainQueue my_drivetrain_queue_;
+  double last_left_position_;
+  double last_right_position_;
+};
+
+class DrivetrainTest : public ::aos::testing::ControlLoopTest {
+ protected:
+  // Create a new instance of the test queue so that it invalidates the queue
+  // that it points to.  Otherwise, we will have a pointer to shared memory that
+  // is no longer valid.
+  DrivetrainQueue my_drivetrain_queue_;
+
+  // Create a loop and simulation plant.
+  DrivetrainLoop drivetrain_motor_;
+  DrivetrainSimulation drivetrain_motor_plant_;
+
+  DrivetrainTest() : my_drivetrain_queue_(".frc971.control_loops.drivetrain",
+                               0x8a8dde77,
+                               ".frc971.control_loops.drivetrain.goal",
+                               ".frc971.control_loops.drivetrain.position",
+                               ".frc971.control_loops.drivetrain.output",
+                               ".frc971.control_loops.drivetrain.status"),
+                drivetrain_motor_(&my_drivetrain_queue_),
+                drivetrain_motor_plant_() {
+    ::frc971::sensors::gyro_reading.Clear();
+  }
+
+  void VerifyNearGoal() {
+    my_drivetrain_queue_.goal.FetchLatest();
+    my_drivetrain_queue_.position.FetchLatest();
+    EXPECT_NEAR(my_drivetrain_queue_.goal->left_goal,
+                drivetrain_motor_plant_.GetLeftPosition(),
+                1e-2);
+    EXPECT_NEAR(my_drivetrain_queue_.goal->right_goal,
+                drivetrain_motor_plant_.GetRightPosition(),
+                1e-2);
+  }
+
+  virtual ~DrivetrainTest() {
+    ::frc971::sensors::gyro_reading.Clear();
+  }
+};
+
+// Tests that the drivetrain converges on a goal.
+TEST_F(DrivetrainTest, ConvergesCorrectly) {
+  my_drivetrain_queue_.goal.MakeWithBuilder().control_loop_driving(true)
+      .left_goal(-1.0)
+      .right_goal(1.0).Send();
+  for (int i = 0; i < 200; ++i) {
+    drivetrain_motor_plant_.SendPositionMessage();
+    drivetrain_motor_.Iterate();
+    drivetrain_motor_plant_.Simulate();
+    SimulateTimestep(true);
+  }
+  VerifyNearGoal();
+}
+
+// Tests that it survives disabling.
+TEST_F(DrivetrainTest, SurvivesDisabling) {
+  my_drivetrain_queue_.goal.MakeWithBuilder().control_loop_driving(true)
+      .left_goal(-1.0)
+      .right_goal(1.0).Send();
+  for (int i = 0; i < 500; ++i) {
+    drivetrain_motor_plant_.SendPositionMessage();
+    drivetrain_motor_.Iterate();
+    drivetrain_motor_plant_.Simulate();
+    if (i > 20 && i < 200) {
+      SimulateTimestep(false);
+    } else {
+      SimulateTimestep(true);
+    }
+  }
+  VerifyNearGoal();
+}
+
+// Tests that never having a goal doesn't break.
+TEST_F(DrivetrainTest, NoGoalStart) {
+  for (int i = 0; i < 20; ++i) {
+    drivetrain_motor_plant_.SendPositionMessage();
+    drivetrain_motor_.Iterate();
+    drivetrain_motor_plant_.Simulate();
+  }
+}
+
+// Tests that never having a goal, but having driver's station messages, doesn't
+// break.
+TEST_F(DrivetrainTest, NoGoalWithRobotState) {
+  for (int i = 0; i < 20; ++i) {
+    drivetrain_motor_plant_.SendPositionMessage();
+    drivetrain_motor_.Iterate();
+    drivetrain_motor_plant_.Simulate();
+    SimulateTimestep(true);
+  }
+}
+
+::aos::controls::HPolytope<2> MakeBox(double x1_min, double x1_max,
+                                      double x2_min, double x2_max) {
+  Eigen::Matrix<double, 4, 2> box_H;
+  box_H << /*[[*/ 1.0, 0.0 /*]*/,
+            /*[*/-1.0, 0.0 /*]*/,
+            /*[*/ 0.0, 1.0 /*]*/,
+            /*[*/ 0.0,-1.0 /*]]*/;
+  Eigen::Matrix<double, 4, 1> box_k;
+  box_k << /*[[*/ x1_max /*]*/,
+            /*[*/-x1_min /*]*/,
+            /*[*/ x2_max /*]*/,
+            /*[*/-x2_min /*]]*/;
+  ::aos::controls::HPolytope<2> t_poly(box_H, box_k);
+  return t_poly;
+}
+
+class CoerceGoalTest : public ::testing::Test {
+ public:
+  EIGEN_MAKE_ALIGNED_OPERATOR_NEW
+};
+
+// WHOOOHH!
+TEST_F(CoerceGoalTest, Inside) {
+  ::aos::controls::HPolytope<2> box = MakeBox(1, 2, 1, 2);
+
+  Eigen::Matrix<double, 1, 2> K;
+  K << /*[[*/ 1, -1 /*]]*/;
+
+  Eigen::Matrix<double, 2, 1> R;
+  R << /*[[*/ 1.5, 1.5 /*]]*/;
+
+  Eigen::Matrix<double, 2, 1> output =
+      ::frc971::control_loops::CoerceGoal(box, K, 0, R);
+
+  EXPECT_EQ(R(0, 0), output(0, 0));
+  EXPECT_EQ(R(1, 0), output(1, 0));
+}
+
+TEST_F(CoerceGoalTest, Outside_Inside_Intersect) {
+  ::aos::controls::HPolytope<2> box = MakeBox(1, 2, 1, 2);
+
+  Eigen::Matrix<double, 1, 2> K;
+  K << 1, -1;
+
+  Eigen::Matrix<double, 2, 1> R;
+  R << 5, 5;
+
+  Eigen::Matrix<double, 2, 1> output =
+      ::frc971::control_loops::CoerceGoal(box, K, 0, R);
+
+  EXPECT_EQ(2.0, output(0, 0));
+  EXPECT_EQ(2.0, output(1, 0));
+}
+
+TEST_F(CoerceGoalTest, Outside_Inside_no_Intersect) {
+  ::aos::controls::HPolytope<2> box = MakeBox(3, 4, 1, 2);
+
+  Eigen::Matrix<double, 1, 2> K;
+  K << 1, -1;
+
+  Eigen::Matrix<double, 2, 1> R;
+  R << 5, 5;
+
+  Eigen::Matrix<double, 2, 1> output =
+      ::frc971::control_loops::CoerceGoal(box, K, 0, R);
+
+  EXPECT_EQ(3.0, output(0, 0));
+  EXPECT_EQ(2.0, output(1, 0));
+}
+
+TEST_F(CoerceGoalTest, Middle_Of_Edge) {
+  ::aos::controls::HPolytope<2> box = MakeBox(0, 4, 1, 2);
+
+  Eigen::Matrix<double, 1, 2> K;
+  K << -1, 1;
+
+  Eigen::Matrix<double, 2, 1> R;
+  R << 5, 5;
+
+  Eigen::Matrix<double, 2, 1> output =
+      ::frc971::control_loops::CoerceGoal(box, K, 0, R);
+
+  EXPECT_EQ(2.0, output(0, 0));
+  EXPECT_EQ(2.0, output(1, 0));
+}
+
+TEST_F(CoerceGoalTest, PerpendicularLine) {
+  ::aos::controls::HPolytope<2> box = MakeBox(1, 2, 1, 2);
+
+  Eigen::Matrix<double, 1, 2> K;
+  K << 1, 1;
+
+  Eigen::Matrix<double, 2, 1> R;
+  R << 5, 5;
+
+  Eigen::Matrix<double, 2, 1> output =
+      ::frc971::control_loops::CoerceGoal(box, K, 0, R);
+
+  EXPECT_EQ(1.0, output(0, 0));
+  EXPECT_EQ(1.0, output(1, 0));
+}
+
+}  // namespace testing
+}  // namespace control_loops
+}  // namespace frc971
diff --git a/y2015/control_loops/drivetrain/drivetrain_main.cc b/y2015/control_loops/drivetrain/drivetrain_main.cc
new file mode 100644
index 0000000..10a50f3
--- /dev/null
+++ b/y2015/control_loops/drivetrain/drivetrain_main.cc
@@ -0,0 +1,11 @@
+#include "y2015/control_loops/drivetrain/drivetrain.h"
+
+#include "aos/linux_code/init.h"
+
+int main() {
+  ::aos::Init();
+  frc971::control_loops::DrivetrainLoop drivetrain;
+  drivetrain.Run();
+  ::aos::Cleanup();
+  return 0;
+}
diff --git a/y2015/control_loops/drivetrain/polydrivetrain_cim_plant.cc b/y2015/control_loops/drivetrain/polydrivetrain_cim_plant.cc
new file mode 100644
index 0000000..36ebb59
--- /dev/null
+++ b/y2015/control_loops/drivetrain/polydrivetrain_cim_plant.cc
@@ -0,0 +1,49 @@
+#include "y2015/control_loops/drivetrain/polydrivetrain_cim_plant.h"
+
+#include <vector>
+
+#include "frc971/control_loops/state_feedback_loop.h"
+
+namespace frc971 {
+namespace control_loops {
+
+StateFeedbackPlantCoefficients<1, 1, 1> MakeCIMPlantCoefficients() {
+  Eigen::Matrix<double, 1, 1> A;
+  A << 0.783924473544;
+  Eigen::Matrix<double, 1, 1> B;
+  B << 8.94979586973;
+  Eigen::Matrix<double, 1, 1> C;
+  C << 1;
+  Eigen::Matrix<double, 1, 1> D;
+  D << 0;
+  Eigen::Matrix<double, 1, 1> U_max;
+  U_max << 12.0;
+  Eigen::Matrix<double, 1, 1> U_min;
+  U_min << -12.0;
+  return StateFeedbackPlantCoefficients<1, 1, 1>(A, B, C, D, U_max, U_min);
+}
+
+StateFeedbackController<1, 1, 1> MakeCIMController() {
+  Eigen::Matrix<double, 1, 1> L;
+  L << 0.773924473544;
+  Eigen::Matrix<double, 1, 1> K;
+  K << 0.086473980503;
+  Eigen::Matrix<double, 1, 1> A_inv;
+  A_inv << 1.2756330919;
+  return StateFeedbackController<1, 1, 1>(L, K, A_inv, MakeCIMPlantCoefficients());
+}
+
+StateFeedbackPlant<1, 1, 1> MakeCIMPlant() {
+  ::std::vector< ::std::unique_ptr<StateFeedbackPlantCoefficients<1, 1, 1>>> plants(1);
+  plants[0] = ::std::unique_ptr<StateFeedbackPlantCoefficients<1, 1, 1>>(new StateFeedbackPlantCoefficients<1, 1, 1>(MakeCIMPlantCoefficients()));
+  return StateFeedbackPlant<1, 1, 1>(&plants);
+}
+
+StateFeedbackLoop<1, 1, 1> MakeCIMLoop() {
+  ::std::vector< ::std::unique_ptr<StateFeedbackController<1, 1, 1>>> controllers(1);
+  controllers[0] = ::std::unique_ptr<StateFeedbackController<1, 1, 1>>(new StateFeedbackController<1, 1, 1>(MakeCIMController()));
+  return StateFeedbackLoop<1, 1, 1>(&controllers);
+}
+
+}  // namespace control_loops
+}  // namespace frc971
diff --git a/y2015/control_loops/drivetrain/polydrivetrain_cim_plant.h b/y2015/control_loops/drivetrain/polydrivetrain_cim_plant.h
new file mode 100644
index 0000000..1c445a7
--- /dev/null
+++ b/y2015/control_loops/drivetrain/polydrivetrain_cim_plant.h
@@ -0,0 +1,20 @@
+#ifndef Y2015_CONTROL_LOOPS_DRIVETRAIN_POLYDRIVETRAIN_CIM_PLANT_H_
+#define Y2015_CONTROL_LOOPS_DRIVETRAIN_POLYDRIVETRAIN_CIM_PLANT_H_
+
+#include "frc971/control_loops/state_feedback_loop.h"
+
+namespace frc971 {
+namespace control_loops {
+
+StateFeedbackPlantCoefficients<1, 1, 1> MakeCIMPlantCoefficients();
+
+StateFeedbackController<1, 1, 1> MakeCIMController();
+
+StateFeedbackPlant<1, 1, 1> MakeCIMPlant();
+
+StateFeedbackLoop<1, 1, 1> MakeCIMLoop();
+
+}  // namespace control_loops
+}  // namespace frc971
+
+#endif  // Y2015_CONTROL_LOOPS_DRIVETRAIN_POLYDRIVETRAIN_CIM_PLANT_H_
diff --git a/y2015/control_loops/drivetrain/polydrivetrain_dog_motor_plant.cc b/y2015/control_loops/drivetrain/polydrivetrain_dog_motor_plant.cc
new file mode 100644
index 0000000..811991c
--- /dev/null
+++ b/y2015/control_loops/drivetrain/polydrivetrain_dog_motor_plant.cc
@@ -0,0 +1,133 @@
+#include "y2015/control_loops/drivetrain/polydrivetrain_dog_motor_plant.h"
+
+#include <vector>
+
+#include "frc971/control_loops/state_feedback_loop.h"
+
+namespace frc971 {
+namespace control_loops {
+
+StateFeedbackPlantCoefficients<2, 2, 2> MakeVelocityDrivetrainLowLowPlantCoefficients() {
+  Eigen::Matrix<double, 2, 2> A;
+  A << 0.955499400541, 0.00962691403749, 0.00962691403749, 0.955499400541;
+  Eigen::Matrix<double, 2, 2> B;
+  B << 0.0164714763931, -0.00356331126397, -0.00356331126397, 0.0164714763931;
+  Eigen::Matrix<double, 2, 2> C;
+  C << 1.0, 0.0, 0.0, 1.0;
+  Eigen::Matrix<double, 2, 2> D;
+  D << 0.0, 0.0, 0.0, 0.0;
+  Eigen::Matrix<double, 2, 1> U_max;
+  U_max << 12.0, 12.0;
+  Eigen::Matrix<double, 2, 1> U_min;
+  U_min << -12.0, -12.0;
+  return StateFeedbackPlantCoefficients<2, 2, 2>(A, B, C, D, U_max, U_min);
+}
+
+StateFeedbackPlantCoefficients<2, 2, 2> MakeVelocityDrivetrainLowHighPlantCoefficients() {
+  Eigen::Matrix<double, 2, 2> A;
+  A << 0.955499400541, 0.00962691403749, 0.00962691403749, 0.955499400541;
+  Eigen::Matrix<double, 2, 2> B;
+  B << 0.0164714763931, -0.00356331126397, -0.00356331126397, 0.0164714763931;
+  Eigen::Matrix<double, 2, 2> C;
+  C << 1.0, 0.0, 0.0, 1.0;
+  Eigen::Matrix<double, 2, 2> D;
+  D << 0.0, 0.0, 0.0, 0.0;
+  Eigen::Matrix<double, 2, 1> U_max;
+  U_max << 12.0, 12.0;
+  Eigen::Matrix<double, 2, 1> U_min;
+  U_min << -12.0, -12.0;
+  return StateFeedbackPlantCoefficients<2, 2, 2>(A, B, C, D, U_max, U_min);
+}
+
+StateFeedbackPlantCoefficients<2, 2, 2> MakeVelocityDrivetrainHighLowPlantCoefficients() {
+  Eigen::Matrix<double, 2, 2> A;
+  A << 0.955499400541, 0.00962691403749, 0.00962691403749, 0.955499400541;
+  Eigen::Matrix<double, 2, 2> B;
+  B << 0.0164714763931, -0.00356331126397, -0.00356331126397, 0.0164714763931;
+  Eigen::Matrix<double, 2, 2> C;
+  C << 1.0, 0.0, 0.0, 1.0;
+  Eigen::Matrix<double, 2, 2> D;
+  D << 0.0, 0.0, 0.0, 0.0;
+  Eigen::Matrix<double, 2, 1> U_max;
+  U_max << 12.0, 12.0;
+  Eigen::Matrix<double, 2, 1> U_min;
+  U_min << -12.0, -12.0;
+  return StateFeedbackPlantCoefficients<2, 2, 2>(A, B, C, D, U_max, U_min);
+}
+
+StateFeedbackPlantCoefficients<2, 2, 2> MakeVelocityDrivetrainHighHighPlantCoefficients() {
+  Eigen::Matrix<double, 2, 2> A;
+  A << 0.955499400541, 0.00962691403749, 0.00962691403749, 0.955499400541;
+  Eigen::Matrix<double, 2, 2> B;
+  B << 0.0164714763931, -0.00356331126397, -0.00356331126397, 0.0164714763931;
+  Eigen::Matrix<double, 2, 2> C;
+  C << 1.0, 0.0, 0.0, 1.0;
+  Eigen::Matrix<double, 2, 2> D;
+  D << 0.0, 0.0, 0.0, 0.0;
+  Eigen::Matrix<double, 2, 1> U_max;
+  U_max << 12.0, 12.0;
+  Eigen::Matrix<double, 2, 1> U_min;
+  U_min << -12.0, -12.0;
+  return StateFeedbackPlantCoefficients<2, 2, 2>(A, B, C, D, U_max, U_min);
+}
+
+StateFeedbackController<2, 2, 2> MakeVelocityDrivetrainLowLowController() {
+  Eigen::Matrix<double, 2, 2> L;
+  L << 0.935499400541, 0.00962691403749, 0.00962691403749, 0.935499400541;
+  Eigen::Matrix<double, 2, 2> K;
+  K << 22.7750288573, 5.51143253556, 5.51143253556, 22.7750288573;
+  Eigen::Matrix<double, 2, 2> A_inv;
+  A_inv << 1.04667938127, -0.010545576923, -0.010545576923, 1.04667938127;
+  return StateFeedbackController<2, 2, 2>(L, K, A_inv, MakeVelocityDrivetrainLowLowPlantCoefficients());
+}
+
+StateFeedbackController<2, 2, 2> MakeVelocityDrivetrainLowHighController() {
+  Eigen::Matrix<double, 2, 2> L;
+  L << 0.935499400541, 0.00962691403749, 0.00962691403749, 0.935499400541;
+  Eigen::Matrix<double, 2, 2> K;
+  K << 22.7750288573, 5.51143253556, 5.51143253556, 22.7750288573;
+  Eigen::Matrix<double, 2, 2> A_inv;
+  A_inv << 1.04667938127, -0.010545576923, -0.010545576923, 1.04667938127;
+  return StateFeedbackController<2, 2, 2>(L, K, A_inv, MakeVelocityDrivetrainLowHighPlantCoefficients());
+}
+
+StateFeedbackController<2, 2, 2> MakeVelocityDrivetrainHighLowController() {
+  Eigen::Matrix<double, 2, 2> L;
+  L << 0.935499400541, 0.00962691403749, 0.00962691403749, 0.935499400541;
+  Eigen::Matrix<double, 2, 2> K;
+  K << 22.7750288573, 5.51143253556, 5.51143253556, 22.7750288573;
+  Eigen::Matrix<double, 2, 2> A_inv;
+  A_inv << 1.04667938127, -0.010545576923, -0.010545576923, 1.04667938127;
+  return StateFeedbackController<2, 2, 2>(L, K, A_inv, MakeVelocityDrivetrainHighLowPlantCoefficients());
+}
+
+StateFeedbackController<2, 2, 2> MakeVelocityDrivetrainHighHighController() {
+  Eigen::Matrix<double, 2, 2> L;
+  L << 0.935499400541, 0.00962691403749, 0.00962691403749, 0.935499400541;
+  Eigen::Matrix<double, 2, 2> K;
+  K << 22.7750288573, 5.51143253556, 5.51143253556, 22.7750288573;
+  Eigen::Matrix<double, 2, 2> A_inv;
+  A_inv << 1.04667938127, -0.010545576923, -0.010545576923, 1.04667938127;
+  return StateFeedbackController<2, 2, 2>(L, K, A_inv, MakeVelocityDrivetrainHighHighPlantCoefficients());
+}
+
+StateFeedbackPlant<2, 2, 2> MakeVelocityDrivetrainPlant() {
+  ::std::vector< ::std::unique_ptr<StateFeedbackPlantCoefficients<2, 2, 2>>> plants(4);
+  plants[0] = ::std::unique_ptr<StateFeedbackPlantCoefficients<2, 2, 2>>(new StateFeedbackPlantCoefficients<2, 2, 2>(MakeVelocityDrivetrainLowLowPlantCoefficients()));
+  plants[1] = ::std::unique_ptr<StateFeedbackPlantCoefficients<2, 2, 2>>(new StateFeedbackPlantCoefficients<2, 2, 2>(MakeVelocityDrivetrainLowHighPlantCoefficients()));
+  plants[2] = ::std::unique_ptr<StateFeedbackPlantCoefficients<2, 2, 2>>(new StateFeedbackPlantCoefficients<2, 2, 2>(MakeVelocityDrivetrainHighLowPlantCoefficients()));
+  plants[3] = ::std::unique_ptr<StateFeedbackPlantCoefficients<2, 2, 2>>(new StateFeedbackPlantCoefficients<2, 2, 2>(MakeVelocityDrivetrainHighHighPlantCoefficients()));
+  return StateFeedbackPlant<2, 2, 2>(&plants);
+}
+
+StateFeedbackLoop<2, 2, 2> MakeVelocityDrivetrainLoop() {
+  ::std::vector< ::std::unique_ptr<StateFeedbackController<2, 2, 2>>> controllers(4);
+  controllers[0] = ::std::unique_ptr<StateFeedbackController<2, 2, 2>>(new StateFeedbackController<2, 2, 2>(MakeVelocityDrivetrainLowLowController()));
+  controllers[1] = ::std::unique_ptr<StateFeedbackController<2, 2, 2>>(new StateFeedbackController<2, 2, 2>(MakeVelocityDrivetrainLowHighController()));
+  controllers[2] = ::std::unique_ptr<StateFeedbackController<2, 2, 2>>(new StateFeedbackController<2, 2, 2>(MakeVelocityDrivetrainHighLowController()));
+  controllers[3] = ::std::unique_ptr<StateFeedbackController<2, 2, 2>>(new StateFeedbackController<2, 2, 2>(MakeVelocityDrivetrainHighHighController()));
+  return StateFeedbackLoop<2, 2, 2>(&controllers);
+}
+
+}  // namespace control_loops
+}  // namespace frc971
diff --git a/y2015/control_loops/drivetrain/polydrivetrain_dog_motor_plant.h b/y2015/control_loops/drivetrain/polydrivetrain_dog_motor_plant.h
new file mode 100644
index 0000000..5a99caf
--- /dev/null
+++ b/y2015/control_loops/drivetrain/polydrivetrain_dog_motor_plant.h
@@ -0,0 +1,32 @@
+#ifndef Y2015_CONTROL_LOOPS_DRIVETRAIN_POLYDRIVETRAIN_DOG_MOTOR_PLANT_H_
+#define Y2015_CONTROL_LOOPS_DRIVETRAIN_POLYDRIVETRAIN_DOG_MOTOR_PLANT_H_
+
+#include "frc971/control_loops/state_feedback_loop.h"
+
+namespace frc971 {
+namespace control_loops {
+
+StateFeedbackPlantCoefficients<2, 2, 2> MakeVelocityDrivetrainLowLowPlantCoefficients();
+
+StateFeedbackController<2, 2, 2> MakeVelocityDrivetrainLowLowController();
+
+StateFeedbackPlantCoefficients<2, 2, 2> MakeVelocityDrivetrainLowHighPlantCoefficients();
+
+StateFeedbackController<2, 2, 2> MakeVelocityDrivetrainLowHighController();
+
+StateFeedbackPlantCoefficients<2, 2, 2> MakeVelocityDrivetrainHighLowPlantCoefficients();
+
+StateFeedbackController<2, 2, 2> MakeVelocityDrivetrainHighLowController();
+
+StateFeedbackPlantCoefficients<2, 2, 2> MakeVelocityDrivetrainHighHighPlantCoefficients();
+
+StateFeedbackController<2, 2, 2> MakeVelocityDrivetrainHighHighController();
+
+StateFeedbackPlant<2, 2, 2> MakeVelocityDrivetrainPlant();
+
+StateFeedbackLoop<2, 2, 2> MakeVelocityDrivetrainLoop();
+
+}  // namespace control_loops
+}  // namespace frc971
+
+#endif  // Y2015_CONTROL_LOOPS_DRIVETRAIN_POLYDRIVETRAIN_DOG_MOTOR_PLANT_H_
diff --git a/y2015/control_loops/drivetrain/replay_drivetrain.cc b/y2015/control_loops/drivetrain/replay_drivetrain.cc
new file mode 100644
index 0000000..030a945
--- /dev/null
+++ b/y2015/control_loops/drivetrain/replay_drivetrain.cc
@@ -0,0 +1,24 @@
+#include "aos/common/controls/replay_control_loop.h"
+#include "aos/linux_code/init.h"
+
+#include "y2015/control_loops/drivetrain/drivetrain.q.h"
+
+// Reads one or more log files and sends out all the queue messages (in the
+// correct order and at the correct time) to feed a "live" drivetrain process.
+
+int main(int argc, char **argv) {
+  if (argc <= 1) {
+    fprintf(stderr, "Need at least one file to replay!\n");
+    return EXIT_FAILURE;
+  }
+
+  ::aos::InitNRT();
+
+  ::aos::controls::ControlLoopReplayer<::frc971::control_loops::DrivetrainQueue>
+      replayer(&::frc971::control_loops::drivetrain_queue, "drivetrain");
+  for (int i = 1; i < argc; ++i) {
+    replayer.ProcessFile(argv[i]);
+  }
+
+  ::aos::Cleanup();
+}
diff --git a/y2015/control_loops/fridge/arm_motor_plant.cc b/y2015/control_loops/fridge/arm_motor_plant.cc
new file mode 100644
index 0000000..6e3205a
--- /dev/null
+++ b/y2015/control_loops/fridge/arm_motor_plant.cc
@@ -0,0 +1,49 @@
+#include "y2015/control_loops/fridge/arm_motor_plant.h"
+
+#include <vector>
+
+#include "frc971/control_loops/state_feedback_loop.h"
+
+namespace frc971 {
+namespace control_loops {
+
+StateFeedbackPlantCoefficients<4, 2, 2> MakeArmPlantCoefficients() {
+  Eigen::Matrix<double, 4, 4> A;
+  A << 1.0, 0.00479642025454, 0.0, 0.0, 0.0, 0.919688585028, 0.0, 0.0, 0.0, 0.0, 0.999539771613, 0.00479566382645, 0.0, 0.0, -0.18154390621, 0.919241022297;
+  Eigen::Matrix<double, 4, 2> B;
+  B << 2.46496779984e-05, 2.46496779984e-05, 0.00972420175808, 0.00972420175808, 2.46477449538e-05, -2.46477449538e-05, 0.00972266818532, -0.00972266818532;
+  Eigen::Matrix<double, 2, 4> C;
+  C << 1, 0, 1, 0, 1, 0, -1, 0;
+  Eigen::Matrix<double, 2, 2> D;
+  D << 0, 0, 0, 0;
+  Eigen::Matrix<double, 2, 1> U_max;
+  U_max << 12.0, 12.0;
+  Eigen::Matrix<double, 2, 1> U_min;
+  U_min << -12.0, -12.0;
+  return StateFeedbackPlantCoefficients<4, 2, 2>(A, B, C, D, U_max, U_min);
+}
+
+StateFeedbackController<4, 2, 2> MakeArmController() {
+  Eigen::Matrix<double, 4, 2> L;
+  L << 0.759844292514, 0.759844292514, 54.2541762188, 54.2541762188, 0.759390396955, -0.759390396955, 54.1048167043, -54.1048167043;
+  Eigen::Matrix<double, 2, 4> K;
+  K << 320.979606093, 21.0129517955, 884.233784759, 36.3637782119, 320.979606095, 21.0129517956, -884.233784749, -36.3637782119;
+  Eigen::Matrix<double, 4, 4> A_inv;
+  A_inv << 1.0, -0.00521526561559, 0.0, 0.0, 0.0, 1.08732457517, 0.0, 0.0, 0.0, 0.0, 0.999513354044, -0.00521444313273, 0.0, 0.0, 0.197397150694, 1.08682415753;
+  return StateFeedbackController<4, 2, 2>(L, K, A_inv, MakeArmPlantCoefficients());
+}
+
+StateFeedbackPlant<4, 2, 2> MakeArmPlant() {
+  ::std::vector< ::std::unique_ptr<StateFeedbackPlantCoefficients<4, 2, 2>>> plants(1);
+  plants[0] = ::std::unique_ptr<StateFeedbackPlantCoefficients<4, 2, 2>>(new StateFeedbackPlantCoefficients<4, 2, 2>(MakeArmPlantCoefficients()));
+  return StateFeedbackPlant<4, 2, 2>(&plants);
+}
+
+StateFeedbackLoop<4, 2, 2> MakeArmLoop() {
+  ::std::vector< ::std::unique_ptr<StateFeedbackController<4, 2, 2>>> controllers(1);
+  controllers[0] = ::std::unique_ptr<StateFeedbackController<4, 2, 2>>(new StateFeedbackController<4, 2, 2>(MakeArmController()));
+  return StateFeedbackLoop<4, 2, 2>(&controllers);
+}
+
+}  // namespace control_loops
+}  // namespace frc971
diff --git a/y2015/control_loops/fridge/arm_motor_plant.h b/y2015/control_loops/fridge/arm_motor_plant.h
new file mode 100644
index 0000000..3bf8d09
--- /dev/null
+++ b/y2015/control_loops/fridge/arm_motor_plant.h
@@ -0,0 +1,20 @@
+#ifndef Y2015_CONTROL_LOOPS_FRIDGE_ARM_MOTOR_PLANT_H_
+#define Y2015_CONTROL_LOOPS_FRIDGE_ARM_MOTOR_PLANT_H_
+
+#include "frc971/control_loops/state_feedback_loop.h"
+
+namespace frc971 {
+namespace control_loops {
+
+StateFeedbackPlantCoefficients<4, 2, 2> MakeArmPlantCoefficients();
+
+StateFeedbackController<4, 2, 2> MakeArmController();
+
+StateFeedbackPlant<4, 2, 2> MakeArmPlant();
+
+StateFeedbackLoop<4, 2, 2> MakeArmLoop();
+
+}  // namespace control_loops
+}  // namespace frc971
+
+#endif  // Y2015_CONTROL_LOOPS_FRIDGE_ARM_MOTOR_PLANT_H_
diff --git a/y2015/control_loops/fridge/elevator_motor_plant.cc b/y2015/control_loops/fridge/elevator_motor_plant.cc
new file mode 100644
index 0000000..995d838
--- /dev/null
+++ b/y2015/control_loops/fridge/elevator_motor_plant.cc
@@ -0,0 +1,49 @@
+#include "y2015/control_loops/fridge/elevator_motor_plant.h"
+
+#include <vector>
+
+#include "frc971/control_loops/state_feedback_loop.h"
+
+namespace frc971 {
+namespace control_loops {
+
+StateFeedbackPlantCoefficients<4, 2, 2> MakeElevatorPlantCoefficients() {
+  Eigen::Matrix<double, 4, 4> A;
+  A << 1.0, 0.00435668193669, 0.0, 0.0, 0.0, 0.754212786054, 0.0, 0.0, 0.0, 0.0, 0.997194498569, 0.00435222083164, 0.0, 0.0, -1.07131589702, 0.751658962986;
+  Eigen::Matrix<double, 4, 2> B;
+  B << 3.82580284276e-05, 3.82580284276e-05, 0.0146169286307, 0.0146169286307, 3.82387898839e-05, -3.82387898839e-05, 0.0146019613563, -0.0146019613563;
+  Eigen::Matrix<double, 2, 4> C;
+  C << 1, 0, 1, 0, 1, 0, -1, 0;
+  Eigen::Matrix<double, 2, 2> D;
+  D << 0, 0, 0, 0;
+  Eigen::Matrix<double, 2, 1> U_max;
+  U_max << 12.0, 12.0;
+  Eigen::Matrix<double, 2, 1> U_min;
+  U_min << -12.0, -12.0;
+  return StateFeedbackPlantCoefficients<4, 2, 2>(A, B, C, D, U_max, U_min);
+}
+
+StateFeedbackController<4, 2, 2> MakeElevatorController() {
+  Eigen::Matrix<double, 4, 2> L;
+  L << 0.677106393027, 0.677106393027, 35.5375738607, 35.5375738607, 0.674426730777, -0.674426730777, 34.7138874344, -34.7138874344;
+  Eigen::Matrix<double, 2, 4> K;
+  K << 321.310606763, 11.7674534233, 601.047935717, 12.6977148843, 321.310606764, 11.7674534233, -601.047935716, -12.6977148843;
+  Eigen::Matrix<double, 4, 4> A_inv;
+  A_inv << 1.0, -0.00577646258091, 0.0, 0.0, 0.0, 1.32588576923, 0.0, 0.0, 0.0, 0.0, 0.996613922337, -0.00577054766522, 0.0, 0.0, 1.42044250221, 1.32216599481;
+  return StateFeedbackController<4, 2, 2>(L, K, A_inv, MakeElevatorPlantCoefficients());
+}
+
+StateFeedbackPlant<4, 2, 2> MakeElevatorPlant() {
+  ::std::vector< ::std::unique_ptr<StateFeedbackPlantCoefficients<4, 2, 2>>> plants(1);
+  plants[0] = ::std::unique_ptr<StateFeedbackPlantCoefficients<4, 2, 2>>(new StateFeedbackPlantCoefficients<4, 2, 2>(MakeElevatorPlantCoefficients()));
+  return StateFeedbackPlant<4, 2, 2>(&plants);
+}
+
+StateFeedbackLoop<4, 2, 2> MakeElevatorLoop() {
+  ::std::vector< ::std::unique_ptr<StateFeedbackController<4, 2, 2>>> controllers(1);
+  controllers[0] = ::std::unique_ptr<StateFeedbackController<4, 2, 2>>(new StateFeedbackController<4, 2, 2>(MakeElevatorController()));
+  return StateFeedbackLoop<4, 2, 2>(&controllers);
+}
+
+}  // namespace control_loops
+}  // namespace frc971
diff --git a/y2015/control_loops/fridge/elevator_motor_plant.h b/y2015/control_loops/fridge/elevator_motor_plant.h
new file mode 100644
index 0000000..e68e6d7
--- /dev/null
+++ b/y2015/control_loops/fridge/elevator_motor_plant.h
@@ -0,0 +1,20 @@
+#ifndef Y2015_CONTROL_LOOPS_FRIDGE_ELEVATOR_MOTOR_PLANT_H_
+#define Y2015_CONTROL_LOOPS_FRIDGE_ELEVATOR_MOTOR_PLANT_H_
+
+#include "frc971/control_loops/state_feedback_loop.h"
+
+namespace frc971 {
+namespace control_loops {
+
+StateFeedbackPlantCoefficients<4, 2, 2> MakeElevatorPlantCoefficients();
+
+StateFeedbackController<4, 2, 2> MakeElevatorController();
+
+StateFeedbackPlant<4, 2, 2> MakeElevatorPlant();
+
+StateFeedbackLoop<4, 2, 2> MakeElevatorLoop();
+
+}  // namespace control_loops
+}  // namespace frc971
+
+#endif  // Y2015_CONTROL_LOOPS_FRIDGE_ELEVATOR_MOTOR_PLANT_H_
diff --git a/y2015/control_loops/fridge/fridge.cc b/y2015/control_loops/fridge/fridge.cc
new file mode 100644
index 0000000..083baf2
--- /dev/null
+++ b/y2015/control_loops/fridge/fridge.cc
@@ -0,0 +1,720 @@
+#include "y2015/control_loops/fridge/fridge.h"
+
+#include <cmath>
+
+#include "aos/common/controls/control_loops.q.h"
+#include "aos/common/logging/logging.h"
+
+#include "y2015/control_loops/fridge/elevator_motor_plant.h"
+#include "y2015/control_loops/fridge/integral_arm_plant.h"
+#include "frc971/control_loops/voltage_cap/voltage_cap.h"
+#include "frc971/zeroing/zeroing.h"
+
+#include "y2015/constants.h"
+
+namespace frc971 {
+namespace control_loops {
+
+namespace {
+constexpr double kZeroingVoltage = 4.0;
+constexpr double kElevatorZeroingVelocity = 0.10;
+// What speed we move to our safe height at.
+constexpr double kElevatorSafeHeightVelocity = 0.3;
+constexpr double kArmZeroingVelocity = 0.20;
+}  // namespace
+
+template <int S>
+void CappedStateFeedbackLoop<S>::CapU() {
+  VoltageCap(max_voltage_, this->U(0, 0), this->U(1, 0), &this->mutable_U(0, 0),
+             &this->mutable_U(1, 0));
+}
+
+template <int S>
+Eigen::Matrix<double, 2, 1>
+CappedStateFeedbackLoop<S>::UnsaturateOutputGoalChange() {
+  // Compute the K matrix used to compensate for position errors.
+  Eigen::Matrix<double, 2, 2> Kp;
+  Kp.setZero();
+  Kp.col(0) = this->K().col(0);
+  Kp.col(1) = this->K().col(2);
+
+  Eigen::Matrix<double, 2, 2> Kp_inv = Kp.inverse();
+
+  // Compute how much we need to change R in order to achieve the change in U
+  // that was observed.
+  Eigen::Matrix<double, 2, 1> deltaR =
+      -Kp_inv * (this->U_uncapped() - this->U());
+  return deltaR;
+}
+
+Fridge::Fridge(control_loops::FridgeQueue *fridge)
+    : aos::controls::ControlLoop<control_loops::FridgeQueue>(fridge),
+      arm_loop_(new CappedStateFeedbackLoop<5>(
+          StateFeedbackLoop<5, 2, 2>(MakeIntegralArmLoop()))),
+      elevator_loop_(new CappedStateFeedbackLoop<4>(
+          StateFeedbackLoop<4, 2, 2>(MakeElevatorLoop()))),
+      left_arm_estimator_(constants::GetValues().fridge.left_arm_zeroing),
+      right_arm_estimator_(constants::GetValues().fridge.right_arm_zeroing),
+      left_elevator_estimator_(constants::GetValues().fridge.left_elev_zeroing),
+      right_elevator_estimator_(
+          constants::GetValues().fridge.right_elev_zeroing),
+      last_profiling_type_(ProfilingType::ANGLE_HEIGHT_PROFILING),
+      kinematics_(constants::GetValues().fridge.arm_length,
+                  constants::GetValues().fridge.elevator.upper_limit,
+                  constants::GetValues().fridge.elevator.lower_limit,
+                  constants::GetValues().fridge.arm.upper_limit,
+                  constants::GetValues().fridge.arm.lower_limit),
+      arm_profile_(::aos::controls::kLoopFrequency),
+      elevator_profile_(::aos::controls::kLoopFrequency),
+      x_profile_(::aos::controls::kLoopFrequency),
+      y_profile_(::aos::controls::kLoopFrequency) {}
+
+void Fridge::UpdateZeroingState() {
+  if (left_elevator_estimator_.offset_ratio_ready() < 1.0 ||
+      right_elevator_estimator_.offset_ratio_ready() < 1.0 ||
+      left_arm_estimator_.offset_ratio_ready() < 1.0 ||
+      right_arm_estimator_.offset_ratio_ready() < 1.0) {
+    state_ = INITIALIZING;
+  } else if (!left_elevator_estimator_.zeroed() ||
+             !right_elevator_estimator_.zeroed()) {
+    state_ = ZEROING_ELEVATOR;
+  } else if (!left_arm_estimator_.zeroed() || !right_arm_estimator_.zeroed()) {
+    state_ = ZEROING_ARM;
+  } else {
+    state_ = RUNNING;
+  }
+}
+
+void Fridge::Correct() {
+  {
+    Eigen::Matrix<double, 2, 1> Y;
+    Y << left_elevator(), right_elevator();
+    elevator_loop_->Correct(Y);
+  }
+
+  {
+    Eigen::Matrix<double, 2, 1> Y;
+    Y << left_arm(), right_arm();
+    arm_loop_->Correct(Y);
+  }
+}
+
+void Fridge::SetElevatorOffset(double left_offset, double right_offset) {
+  LOG(INFO, "Changing Elevator offset from %f, %f to %f, %f\n",
+      left_elevator_offset_, right_elevator_offset_, left_offset, right_offset);
+  double left_doffset = left_offset - left_elevator_offset_;
+  double right_doffset = right_offset - right_elevator_offset_;
+
+  // Adjust the average height and height difference between the two sides.
+  // The derivatives of both should not need to be updated since the speeds
+  // haven't changed.
+  // The height difference is calculated as left - right, not right - left.
+  elevator_loop_->mutable_X_hat(0, 0) += (left_doffset + right_doffset) / 2;
+  elevator_loop_->mutable_X_hat(2, 0) += (left_doffset - right_doffset) / 2;
+
+  // Modify the zeroing goal.
+  elevator_goal_ += (left_doffset + right_doffset) / 2;
+
+  // Update the cached offset values to the actual values.
+  left_elevator_offset_ = left_offset;
+  right_elevator_offset_ = right_offset;
+}
+
+void Fridge::SetArmOffset(double left_offset, double right_offset) {
+  LOG(INFO, "Changing Arm offset from %f, %f to %f, %f\n", left_arm_offset_,
+      right_arm_offset_, left_offset, right_offset);
+  double left_doffset = left_offset - left_arm_offset_;
+  double right_doffset = right_offset - right_arm_offset_;
+
+  // Adjust the average angle and angle difference between the two sides.
+  // The derivatives of both should not need to be updated since the speeds
+  // haven't changed.
+  arm_loop_->mutable_X_hat(0, 0) += (left_doffset + right_doffset) / 2;
+  arm_loop_->mutable_X_hat(2, 0) += (left_doffset - right_doffset) / 2;
+
+  // Modify the zeroing goal.
+  arm_goal_ += (left_doffset + right_doffset) / 2;
+
+  // Update the cached offset values to the actual values.
+  left_arm_offset_ = left_offset;
+  right_arm_offset_ = right_offset;
+}
+
+double Fridge::estimated_left_elevator() {
+  return current_position_.elevator.left.encoder +
+         left_elevator_estimator_.offset();
+}
+double Fridge::estimated_right_elevator() {
+  return current_position_.elevator.right.encoder +
+         right_elevator_estimator_.offset();
+}
+
+double Fridge::estimated_elevator() {
+  return (estimated_left_elevator() + estimated_right_elevator()) / 2.0;
+}
+
+double Fridge::estimated_left_arm() {
+  return current_position_.arm.left.encoder + left_arm_estimator_.offset();
+}
+double Fridge::estimated_right_arm() {
+  return current_position_.arm.right.encoder + right_arm_estimator_.offset();
+}
+double Fridge::estimated_arm() {
+  return (estimated_left_arm() + estimated_right_arm()) / 2.0;
+}
+
+double Fridge::left_elevator() {
+  return current_position_.elevator.left.encoder + left_elevator_offset_;
+}
+double Fridge::right_elevator() {
+  return current_position_.elevator.right.encoder + right_elevator_offset_;
+}
+
+double Fridge::elevator() { return (left_elevator() + right_elevator()) / 2.0; }
+
+double Fridge::left_arm() {
+  return current_position_.arm.left.encoder + left_arm_offset_;
+}
+double Fridge::right_arm() {
+  return current_position_.arm.right.encoder + right_arm_offset_;
+}
+double Fridge::arm() { return (left_arm() + right_arm()) / 2.0; }
+
+double Fridge::elevator_zeroing_velocity() {
+  double average_elevator =
+      (constants::GetValues().fridge.elevator.lower_limit +
+       constants::GetValues().fridge.elevator.upper_limit) /
+      2.0;
+
+  const double pulse_width = ::std::max(
+      constants::GetValues().fridge.left_elev_zeroing.index_difference,
+      constants::GetValues().fridge.right_elev_zeroing.index_difference);
+
+  if (elevator_zeroing_velocity_ == 0) {
+    if (estimated_elevator() > average_elevator) {
+      elevator_zeroing_velocity_ = -kElevatorZeroingVelocity;
+    } else {
+      elevator_zeroing_velocity_ = kElevatorZeroingVelocity;
+    }
+  } else if (elevator_zeroing_velocity_ > 0 &&
+             estimated_elevator() > average_elevator + 1.1 * pulse_width) {
+    elevator_zeroing_velocity_ = -kElevatorZeroingVelocity;
+  } else if (elevator_zeroing_velocity_ < 0 &&
+             estimated_elevator() < average_elevator - 1.1 * pulse_width) {
+    elevator_zeroing_velocity_ = kElevatorZeroingVelocity;
+  }
+  return elevator_zeroing_velocity_;
+}
+
+double Fridge::UseUnlessZero(double target_value, double default_value) {
+  if (target_value != 0.0) {
+    return target_value;
+  } else {
+    return default_value;
+  }
+}
+
+double Fridge::arm_zeroing_velocity() {
+  const double average_arm = (constants::GetValues().fridge.arm.lower_limit +
+                              constants::GetValues().fridge.arm.upper_limit) /
+                             2.0;
+  const double pulse_width = ::std::max(
+      constants::GetValues().fridge.right_arm_zeroing.index_difference,
+      constants::GetValues().fridge.left_arm_zeroing.index_difference);
+
+  if (arm_zeroing_velocity_ == 0) {
+    if (estimated_arm() > average_arm) {
+      arm_zeroing_velocity_ = -kArmZeroingVelocity;
+    } else {
+      arm_zeroing_velocity_ = kArmZeroingVelocity;
+    }
+  } else if (arm_zeroing_velocity_ > 0.0 &&
+             estimated_arm() > average_arm + 1.1 * pulse_width) {
+    arm_zeroing_velocity_ = -kArmZeroingVelocity;
+  } else if (arm_zeroing_velocity_ < 0.0 && estimated_arm() < average_arm) {
+    arm_zeroing_velocity_ = kArmZeroingVelocity;
+  }
+  return arm_zeroing_velocity_;
+}
+
+void Fridge::RunIteration(const control_loops::FridgeQueue::Goal *unsafe_goal,
+                          const control_loops::FridgeQueue::Position *position,
+                          control_loops::FridgeQueue::Output *output,
+                          control_loops::FridgeQueue::Status *status) {
+  if (WasReset()) {
+    LOG(ERROR, "WPILib reset, restarting\n");
+    left_elevator_estimator_.Reset();
+    right_elevator_estimator_.Reset();
+    left_arm_estimator_.Reset();
+    right_arm_estimator_.Reset();
+    state_ = UNINITIALIZED;
+  }
+
+  // Get a reference to the constants struct since we use it so often in this
+  // code.
+  const auto &values = constants::GetValues();
+
+  // Bool to track if we should turn the motors on or not.
+  bool disable = output == nullptr;
+
+  // Save the current position so it can be used easily in the class.
+  current_position_ = *position;
+
+  left_elevator_estimator_.UpdateEstimate(position->elevator.left);
+  right_elevator_estimator_.UpdateEstimate(position->elevator.right);
+  left_arm_estimator_.UpdateEstimate(position->arm.left);
+  right_arm_estimator_.UpdateEstimate(position->arm.right);
+
+  if (state_ != UNINITIALIZED) {
+    Correct();
+  }
+
+  // Zeroing will work as follows:
+  // At startup, record the offset of the two halves of the two subsystems.
+  // Then, start moving the elevator towards the center until both halves are
+  // zeroed.
+  // Then, start moving the claw towards the center until both halves are
+  // zeroed.
+  // Then, done!
+
+  // We'll then need code to do sanity checking on values.
+
+  // Now, we need to figure out which way to go.
+
+  switch (state_) {
+    case UNINITIALIZED:
+      LOG(DEBUG, "Uninitialized\n");
+      // Startup.  Assume that we are at the origin everywhere.
+      // This records the encoder offset between the two sides of the elevator.
+      left_elevator_offset_ = -position->elevator.left.encoder;
+      right_elevator_offset_ = -position->elevator.right.encoder;
+      left_arm_offset_ = -position->arm.left.encoder;
+      right_arm_offset_ = -position->arm.right.encoder;
+      elevator_loop_->mutable_X_hat().setZero();
+      arm_loop_->mutable_X_hat().setZero();
+      LOG(INFO, "Initializing arm offsets to %f, %f\n", left_arm_offset_,
+          right_arm_offset_);
+      LOG(INFO, "Initializing elevator offsets to %f, %f\n",
+          left_elevator_offset_, right_elevator_offset_);
+      Correct();
+      state_ = INITIALIZING;
+      disable = true;
+      break;
+
+    case INITIALIZING:
+      LOG(DEBUG, "Waiting for accurate initial position.\n");
+      disable = true;
+      // Update state_ to accurately represent the state of the zeroing
+      // estimators.
+      UpdateZeroingState();
+      if (state_ != INITIALIZING) {
+        // Set the goals to where we are now.
+        elevator_goal_ = elevator();
+        arm_goal_ = arm();
+      }
+      break;
+
+    case ZEROING_ELEVATOR:
+      LOG(DEBUG, "Zeroing elevator\n");
+
+      // Update state_ to accurately represent the state of the zeroing
+      // estimators.
+      UpdateZeroingState();
+      if (left_elevator_estimator_.zeroed() &&
+          right_elevator_estimator_.zeroed()) {
+        SetElevatorOffset(left_elevator_estimator_.offset(),
+                          right_elevator_estimator_.offset());
+        LOG(DEBUG, "Zeroed the elevator!\n");
+
+        if (elevator() < values.fridge.arm_zeroing_height &&
+            state_ != INITIALIZING) {
+          // Move the elevator to a safe height before we start zeroing the arm,
+          // so that we don't crash anything.
+          LOG(DEBUG, "Moving elevator to safe height.\n");
+          if (elevator_goal_ < values.fridge.arm_zeroing_height) {
+            elevator_goal_ += kElevatorSafeHeightVelocity *
+                              ::aos::controls::kLoopFrequency.ToSeconds();
+            elevator_goal_velocity_ = kElevatorSafeHeightVelocity;
+            state_ = ZEROING_ELEVATOR;
+          } else {
+            // We want it stopped at whatever height it's currently set to.
+            elevator_goal_velocity_ = 0;
+          }
+        }
+      } else if (!disable) {
+        elevator_goal_velocity_ = elevator_zeroing_velocity();
+        elevator_goal_ += elevator_goal_velocity_ *
+                          ::aos::controls::kLoopFrequency.ToSeconds();
+      }
+
+      // Bypass motion profiles while we are zeroing.
+      // This is also an important step right after the elevator is zeroed and
+      // we reach into the elevator's state matrix and change it based on the
+      // newly-obtained offset.
+      {
+        Eigen::Matrix<double, 2, 1> current;
+        current.setZero();
+        current << elevator_goal_, elevator_goal_velocity_;
+        elevator_profile_.MoveCurrentState(current);
+      }
+      break;
+
+    case ZEROING_ARM:
+      LOG(DEBUG, "Zeroing the arm\n");
+
+      if (elevator() < values.fridge.arm_zeroing_height - 0.10 ||
+          elevator_goal_ < values.fridge.arm_zeroing_height) {
+        LOG(INFO,
+            "Going back to ZEROING_ELEVATOR until it gets high enough to "
+            "safely zero the arm\n");
+        state_ = ZEROING_ELEVATOR;
+        break;
+      }
+
+      // Update state_ to accurately represent the state of the zeroing
+      // estimators.
+      UpdateZeroingState();
+      if (left_arm_estimator_.zeroed() && right_arm_estimator_.zeroed()) {
+        SetArmOffset(left_arm_estimator_.offset(),
+                     right_arm_estimator_.offset());
+        LOG(DEBUG, "Zeroed the arm!\n");
+      } else if (!disable) {
+        arm_goal_velocity_ = arm_zeroing_velocity();
+        arm_goal_ +=
+            arm_goal_velocity_ * ::aos::controls::kLoopFrequency.ToSeconds();
+      }
+
+      // Bypass motion profiles while we are zeroing.
+      // This is also an important step right after the arm is zeroed and
+      // we reach into the arm's state matrix and change it based on the
+      // newly-obtained offset.
+      {
+        Eigen::Matrix<double, 2, 1> current;
+        current.setZero();
+        current << arm_goal_, arm_goal_velocity_;
+        arm_profile_.MoveCurrentState(current);
+      }
+      break;
+
+    case RUNNING:
+      LOG(DEBUG, "Running!\n");
+      if (unsafe_goal) {
+        // Handle the case where we switch between the types of profiling.
+        ProfilingType new_profiling_type =
+            static_cast<ProfilingType>(unsafe_goal->profiling_type);
+
+        if (last_profiling_type_ != new_profiling_type) {
+          // Reset the height/angle profiles.
+          Eigen::Matrix<double, 2, 1> current;
+          current.setZero();
+          current << arm_goal_, arm_goal_velocity_;
+          arm_profile_.MoveCurrentState(current);
+          current << elevator_goal_, elevator_goal_velocity_;
+          elevator_profile_.MoveCurrentState(current);
+
+          // Reset the x/y profiles.
+          aos::util::ElevatorArmKinematics::KinematicResult x_y_result;
+          kinematics_.ForwardKinematic(elevator_goal_, arm_goal_,
+                                       elevator_goal_velocity_,
+                                       arm_goal_velocity_, &x_y_result);
+          current << x_y_result.fridge_x, x_y_result.fridge_x_velocity;
+          x_profile_.MoveCurrentState(current);
+          current << x_y_result.fridge_h, x_y_result.fridge_h_velocity;
+          y_profile_.MoveCurrentState(current);
+
+          last_profiling_type_ = new_profiling_type;
+        }
+
+        if (new_profiling_type == ProfilingType::ANGLE_HEIGHT_PROFILING) {
+          // Pick a set of sane arm defaults if none are specified.
+          arm_profile_.set_maximum_velocity(
+              UseUnlessZero(unsafe_goal->max_angular_velocity, 1.0));
+          arm_profile_.set_maximum_acceleration(
+              UseUnlessZero(unsafe_goal->max_angular_acceleration, 3.0));
+          elevator_profile_.set_maximum_velocity(
+              UseUnlessZero(unsafe_goal->max_velocity, 0.50));
+          elevator_profile_.set_maximum_acceleration(
+              UseUnlessZero(unsafe_goal->max_acceleration, 2.0));
+
+          // Use the profiles to limit the arm's movements.
+          const double unfiltered_arm_goal = ::std::max(
+              ::std::min(unsafe_goal->angle, values.fridge.arm.upper_limit),
+              values.fridge.arm.lower_limit);
+          ::Eigen::Matrix<double, 2, 1> arm_goal_state = arm_profile_.Update(
+              unfiltered_arm_goal, unsafe_goal->angular_velocity);
+          arm_goal_ = arm_goal_state(0, 0);
+          arm_goal_velocity_ = arm_goal_state(1, 0);
+
+          // Use the profiles to limit the elevator's movements.
+          const double unfiltered_elevator_goal =
+              ::std::max(::std::min(unsafe_goal->height,
+                                    values.fridge.elevator.upper_limit),
+                         values.fridge.elevator.lower_limit);
+          ::Eigen::Matrix<double, 2, 1> elevator_goal_state =
+              elevator_profile_.Update(unfiltered_elevator_goal,
+                                       unsafe_goal->velocity);
+          elevator_goal_ = elevator_goal_state(0, 0);
+          elevator_goal_velocity_ = elevator_goal_state(1, 0);
+        } else if (new_profiling_type == ProfilingType::X_Y_PROFILING) {
+          // Use x/y profiling
+          aos::util::ElevatorArmKinematics::KinematicResult kinematic_result;
+
+          x_profile_.set_maximum_velocity(
+              UseUnlessZero(unsafe_goal->max_x_velocity, 0.5));
+          x_profile_.set_maximum_acceleration(
+              UseUnlessZero(unsafe_goal->max_x_acceleration, 2.0));
+          y_profile_.set_maximum_velocity(
+              UseUnlessZero(unsafe_goal->max_y_velocity, 0.50));
+          y_profile_.set_maximum_acceleration(
+              UseUnlessZero(unsafe_goal->max_y_acceleration, 2.0));
+
+          // Limit the goals before we update the profiles.
+          kinematics_.InverseKinematic(
+              unsafe_goal->x, unsafe_goal->y, unsafe_goal->x_velocity,
+              unsafe_goal->y_velocity, &kinematic_result);
+
+          // Use the profiles to limit the x movements.
+          ::Eigen::Matrix<double, 2, 1> x_goal_state = x_profile_.Update(
+              kinematic_result.fridge_x, kinematic_result.fridge_x_velocity);
+
+          // Use the profiles to limit the y movements.
+          ::Eigen::Matrix<double, 2, 1> y_goal_state = y_profile_.Update(
+              kinematic_result.fridge_h, kinematic_result.fridge_h_velocity);
+
+          // Convert x/y goal states into arm/elevator goals.
+          // The inverse kinematics functions automatically perform range
+          // checking and adjust the results so that they're always valid.
+          kinematics_.InverseKinematic(x_goal_state(0, 0), y_goal_state(0, 0),
+                                       x_goal_state(1, 0), y_goal_state(1, 0),
+                                       &kinematic_result);
+
+          // Store the appropriate inverse kinematic results in the
+          // arm/elevator goals.
+          arm_goal_ = kinematic_result.arm_angle;
+          arm_goal_velocity_ = kinematic_result.arm_velocity;
+
+          elevator_goal_ = kinematic_result.elevator_height;
+          elevator_goal_velocity_ = kinematic_result.arm_velocity;
+        } else {
+          LOG(ERROR, "Unknown profiling_type: %d\n",
+              unsafe_goal->profiling_type);
+        }
+      }
+
+      // Update state_ to accurately represent the state of the zeroing
+      // estimators.
+      UpdateZeroingState();
+
+      if (state_ != RUNNING && state_ != ESTOP) {
+        state_ = UNINITIALIZED;
+      }
+      break;
+
+    case ESTOP:
+      LOG(ERROR, "Estop\n");
+      disable = true;
+      break;
+  }
+
+  // Commence death if either left/right tracking error gets too big. This
+  // should run immediately after the SetArmOffset and SetElevatorOffset
+  // functions to double-check that the hardware is in a sane state.
+  if (::std::abs(left_arm() - right_arm()) >=
+      values.max_allowed_left_right_arm_difference) {
+    LOG(ERROR, "The arms are too far apart.  |%f - %f| > %f\n", left_arm(),
+        right_arm(), values.max_allowed_left_right_arm_difference);
+
+    // Indicate an ESTOP condition and stop the motors.
+    if (output) {
+      state_ = ESTOP;
+    }
+    disable = true;
+  }
+
+  if (::std::abs(left_elevator() - right_elevator()) >=
+      values.max_allowed_left_right_elevator_difference) {
+    LOG(ERROR, "The elevators are too far apart.  |%f - %f| > %f\n",
+        left_elevator(), right_elevator(),
+        values.max_allowed_left_right_elevator_difference);
+
+    // Indicate an ESTOP condition and stop the motors.
+    if (output) {
+      state_ = ESTOP;
+    }
+    disable = true;
+  }
+
+  // Limit the goals so we can't exceed the hardware limits if we are RUNNING.
+  if (state_ == RUNNING) {
+    // Limit the arm goal to min/max allowable angles.
+    if (arm_goal_ >= values.fridge.arm.upper_limit) {
+      LOG(WARNING, "Arm goal above limit, %f > %f\n", arm_goal_,
+          values.fridge.arm.upper_limit);
+      arm_goal_ = values.fridge.arm.upper_limit;
+    }
+    if (arm_goal_ <= values.fridge.arm.lower_limit) {
+      LOG(WARNING, "Arm goal below limit, %f < %f\n", arm_goal_,
+          values.fridge.arm.lower_limit);
+      arm_goal_ = values.fridge.arm.lower_limit;
+    }
+
+    // Limit the elevator goal to min/max allowable heights.
+    if (elevator_goal_ >= values.fridge.elevator.upper_limit) {
+      LOG(WARNING, "Elevator goal above limit, %f > %f\n", elevator_goal_,
+          values.fridge.elevator.upper_limit);
+      elevator_goal_ = values.fridge.elevator.upper_limit;
+    }
+    if (elevator_goal_ <= values.fridge.elevator.lower_limit) {
+      LOG(WARNING, "Elevator goal below limit, %f < %f\n", elevator_goal_,
+          values.fridge.elevator.lower_limit);
+      elevator_goal_ = values.fridge.elevator.lower_limit;
+    }
+  }
+
+  // Check the lower level hardware limit as well.
+  if (state_ == RUNNING) {
+    if (left_arm() >= values.fridge.arm.upper_hard_limit ||
+        left_arm() <= values.fridge.arm.lower_hard_limit) {
+      LOG(ERROR, "Left arm at %f out of bounds [%f, %f], ESTOPing\n",
+          left_arm(), values.fridge.arm.lower_hard_limit,
+          values.fridge.arm.upper_hard_limit);
+      if (output) {
+        state_ = ESTOP;
+      }
+    }
+
+    if (right_arm() >= values.fridge.arm.upper_hard_limit ||
+        right_arm() <= values.fridge.arm.lower_hard_limit) {
+      LOG(ERROR, "Right arm at %f out of bounds [%f, %f], ESTOPing\n",
+          right_arm(), values.fridge.arm.lower_hard_limit,
+          values.fridge.arm.upper_hard_limit);
+      if (output) {
+        state_ = ESTOP;
+      }
+    }
+
+    if (left_elevator() >= values.fridge.elevator.upper_hard_limit) {
+      LOG(ERROR, "Left elevator at %f out of bounds [%f, %f], ESTOPing\n",
+          left_elevator(), values.fridge.elevator.lower_hard_limit,
+          values.fridge.elevator.upper_hard_limit);
+      if (output) {
+        state_ = ESTOP;
+      }
+    }
+
+    if (right_elevator() >= values.fridge.elevator.upper_hard_limit) {
+      LOG(ERROR, "Right elevator at %f out of bounds [%f, %f], ESTOPing\n",
+          right_elevator(), values.fridge.elevator.lower_hard_limit,
+          values.fridge.elevator.upper_hard_limit);
+      if (output) {
+        state_ = ESTOP;
+      }
+    }
+  }
+
+  // Set the goals.
+  arm_loop_->mutable_R() << arm_goal_, arm_goal_velocity_, 0.0, 0.0, 0.0;
+  elevator_loop_->mutable_R() << elevator_goal_, elevator_goal_velocity_, 0.0,
+      0.0;
+
+  const double max_voltage = state_ == RUNNING ? 12.0 : kZeroingVoltage;
+  arm_loop_->set_max_voltage(max_voltage);
+  elevator_loop_->set_max_voltage(max_voltage);
+
+  if (state_ == ESTOP) {
+    disable = true;
+  }
+  arm_loop_->Update(disable);
+  elevator_loop_->Update(disable);
+
+  if (state_ == INITIALIZING || state_ == ZEROING_ELEVATOR ||
+      state_ == ZEROING_ARM) {
+    if (arm_loop_->U() != arm_loop_->U_uncapped()) {
+      Eigen::Matrix<double, 2, 1> deltaR =
+          arm_loop_->UnsaturateOutputGoalChange();
+
+      // Move the average arm goal by the amount observed.
+      LOG(WARNING, "Moving arm goal by %f to handle saturation\n",
+          deltaR(0, 0));
+      arm_goal_ += deltaR(0, 0);
+    }
+
+    if (elevator_loop_->U() != elevator_loop_->U_uncapped()) {
+      Eigen::Matrix<double, 2, 1> deltaR =
+          elevator_loop_->UnsaturateOutputGoalChange();
+
+      // Move the average elevator goal by the amount observed.
+      LOG(WARNING, "Moving elevator goal by %f to handle saturation\n",
+          deltaR(0, 0));
+      elevator_goal_ += deltaR(0, 0);
+    }
+  }
+
+  if (output) {
+    output->left_arm = arm_loop_->U(0, 0);
+    output->right_arm = arm_loop_->U(1, 0);
+    output->left_elevator = elevator_loop_->U(0, 0);
+    output->right_elevator = elevator_loop_->U(1, 0);
+    if (unsafe_goal) {
+      output->grabbers = unsafe_goal->grabbers;
+    } else {
+      output->grabbers.top_front = false;
+      output->grabbers.top_back = false;
+      output->grabbers.bottom_front = false;
+      output->grabbers.bottom_back = false;
+    }
+  }
+
+  // TODO(austin): Populate these fully.
+  status->zeroed = state_ == RUNNING;
+
+  status->angle = arm_loop_->X_hat(0, 0);
+  status->angular_velocity = arm_loop_->X_hat(1, 0);
+  status->height = elevator_loop_->X_hat(0, 0);
+  status->velocity = elevator_loop_->X_hat(1, 0);
+
+  status->goal_angle = arm_goal_;
+  status->goal_angular_velocity = arm_goal_velocity_;
+  status->goal_height = elevator_goal_;
+  status->goal_velocity = elevator_goal_velocity_;
+
+  // Populate the same status, but in X/Y co-ordinates.
+  aos::util::ElevatorArmKinematics::KinematicResult x_y_status;
+  kinematics_.ForwardKinematic(status->height, status->angle,
+                               status->velocity, status->angular_velocity,
+                               &x_y_status);
+  status->x = x_y_status.fridge_x;
+  status->y = x_y_status.fridge_h;
+  status->x_velocity = x_y_status.fridge_x_velocity;
+  status->y_velocity = x_y_status.fridge_h_velocity;
+
+  kinematics_.ForwardKinematic(status->goal_height, status->goal_angle,
+                               status->goal_velocity, status->goal_angular_velocity,
+                               &x_y_status);
+  status->goal_x = x_y_status.fridge_x;
+  status->goal_y = x_y_status.fridge_h;
+  status->goal_x_velocity = x_y_status.fridge_x_velocity;
+  status->goal_y_velocity = x_y_status.fridge_h_velocity;
+
+  if (unsafe_goal) {
+    status->grabbers = unsafe_goal->grabbers;
+  } else {
+    status->grabbers.top_front = false;
+    status->grabbers.top_back = false;
+    status->grabbers.bottom_front = false;
+    status->grabbers.bottom_back = false;
+  }
+  zeroing::PopulateEstimatorState(left_arm_estimator_, &status->left_arm_state);
+  zeroing::PopulateEstimatorState(right_arm_estimator_,
+                                  &status->right_arm_state);
+  zeroing::PopulateEstimatorState(left_elevator_estimator_,
+                                  &status->left_elevator_state);
+  zeroing::PopulateEstimatorState(right_elevator_estimator_,
+                                  &status->right_elevator_state);
+  status->estopped = (state_ == ESTOP);
+  status->state = state_;
+  last_state_ = state_;
+}
+
+}  // namespace control_loops
+}  // namespace frc971
diff --git a/y2015/control_loops/fridge/fridge.gyp b/y2015/control_loops/fridge/fridge.gyp
new file mode 100644
index 0000000..76844c4
--- /dev/null
+++ b/y2015/control_loops/fridge/fridge.gyp
@@ -0,0 +1,89 @@
+{
+  'targets': [
+    {
+      'target_name': 'replay_fridge',
+      'type': 'executable',
+      'variables': {
+        'no_rsync': 1,
+      },
+      'sources': [
+        'replay_fridge.cc',
+      ],
+      'dependencies': [
+        'fridge_queue',
+        '<(AOS)/common/controls/controls.gyp:replay_control_loop',
+        '<(AOS)/linux_code/linux_code.gyp:init',
+      ],
+    },
+    {
+      'target_name': 'fridge_queue',
+      'type': 'static_library',
+      'sources': ['fridge.q'],
+      'variables': {
+        'header_path': 'y2015/control_loops/fridge',
+      },
+      'dependencies': [
+        '<(AOS)/common/controls/controls.gyp:control_loop_queues',
+        '<(DEPTH)/frc971/control_loops/control_loops.gyp:queues',
+        '<(DEPTH)/frc971/zeroing/zeroing.gyp:zeroing',
+      ],
+      'export_dependent_settings': [
+        '<(AOS)/common/controls/controls.gyp:control_loop_queues',
+        '<(DEPTH)/frc971/control_loops/control_loops.gyp:queues',
+        '<(DEPTH)/frc971/zeroing/zeroing.gyp:zeroing',
+      ],
+      'includes': ['../../../aos/build/queues.gypi'],
+    },
+    {
+      'target_name': 'fridge_lib',
+      'type': 'static_library',
+      'sources': [
+        'fridge.cc',
+        'integral_arm_plant.cc',
+        'elevator_motor_plant.cc',
+      ],
+      'dependencies': [
+        'fridge_queue',
+        '<(AOS)/common/controls/controls.gyp:control_loop',
+        '<(AOS)/common/util/util.gyp:trapezoid_profile',
+        '<(DEPTH)/y2015/y2015.gyp:constants',
+        '<(DEPTH)/frc971/control_loops/control_loops.gyp:state_feedback_loop',
+        '<(DEPTH)/frc971/control_loops/voltage_cap/voltage_cap.gyp:voltage_cap',
+      ],
+      'export_dependent_settings': [
+        'fridge_queue',
+        '<(AOS)/common/controls/controls.gyp:control_loop',
+        '<(AOS)/common/util/util.gyp:trapezoid_profile',
+        '<(DEPTH)/frc971/control_loops/control_loops.gyp:state_feedback_loop',
+      ],
+    },
+    {
+      'target_name': 'fridge_lib_test',
+      'type': 'executable',
+      'sources': [
+        'fridge_lib_test.cc',
+        'arm_motor_plant.cc',
+      ],
+      'dependencies': [
+        '<(EXTERNALS):gtest',
+        'fridge_lib',
+        '<(DEPTH)/frc971/control_loops/control_loops.gyp:state_feedback_loop',
+        '<(AOS)/common/controls/controls.gyp:control_loop_test',
+        '<(AOS)/common/common.gyp:time',
+        '<(DEPTH)/frc971/control_loops/control_loops.gyp:position_sensor_sim',
+        '<(DEPTH)/frc971/control_loops/control_loops.gyp:team_number_test_environment',
+      ],
+    },
+    {
+      'target_name': 'fridge',
+      'type': 'executable',
+      'sources': [
+        'fridge_main.cc',
+      ],
+      'dependencies': [
+        '<(AOS)/linux_code/linux_code.gyp:init',
+        'fridge_lib',
+      ],
+    },
+  ],
+}
diff --git a/y2015/control_loops/fridge/fridge.h b/y2015/control_loops/fridge/fridge.h
new file mode 100644
index 0000000..0448e09
--- /dev/null
+++ b/y2015/control_loops/fridge/fridge.h
@@ -0,0 +1,172 @@
+#ifndef Y2015_CONTROL_LOOPS_FRIDGE_H_
+#define Y2015_CONTROL_LOOPS_FRIDGE_H_
+
+#include <memory>
+
+#include "aos/common/controls/control_loop.h"
+#include "aos/common/util/trapezoid_profile.h"
+#include "frc971/control_loops/state_feedback_loop.h"
+#include "y2015/control_loops/fridge/fridge.q.h"
+#include "frc971/zeroing/zeroing.h"
+#include "y2015/util/kinematics.h"
+
+namespace frc971 {
+namespace control_loops {
+namespace testing {
+class FridgeTest_DisabledGoalTest_Test;
+class FridgeTest_ArmGoalPositiveWindupTest_Test;
+class FridgeTest_ElevatorGoalPositiveWindupTest_Test;
+class FridgeTest_ArmGoalNegativeWindupTest_Test;
+class FridgeTest_ElevatorGoalNegativeWindupTest_Test;
+class FridgeTest_SafeArmZeroing_Test;
+}  // namespace testing
+
+template<int S>
+class CappedStateFeedbackLoop : public StateFeedbackLoop<S, 2, 2> {
+ public:
+  CappedStateFeedbackLoop(StateFeedbackLoop<S, 2, 2> &&loop)
+      : StateFeedbackLoop<S, 2, 2>(::std::move(loop)), max_voltage_(12.0) {}
+
+  void set_max_voltage(double max_voltage) {
+    max_voltage_ = ::std::max(0.0, ::std::min(12.0, max_voltage));
+  }
+
+  void CapU() override;
+
+  // Returns the amount to change the position goals (average and difference) in
+  // order to no longer saturate the controller.
+  Eigen::Matrix<double, 2, 1> UnsaturateOutputGoalChange();
+
+ private:
+  double max_voltage_;
+};
+
+class Fridge
+    : public aos::controls::ControlLoop<control_loops::FridgeQueue> {
+ public:
+  explicit Fridge(
+      control_loops::FridgeQueue *fridge_queue = &control_loops::fridge_queue);
+
+  enum State {
+    // Waiting to receive data before doing anything.
+    UNINITIALIZED = 0,
+    // Estimating the starting location.
+    INITIALIZING = 1,
+    // Moving the elevator to find an index pulse.
+    ZEROING_ELEVATOR = 2,
+    // Moving the arm to find an index pulse.
+    ZEROING_ARM = 3,
+    // All good!
+    RUNNING = 4,
+    // Internal error caused the fridge to abort.
+    ESTOP = 5,
+  };
+
+  enum class ProfilingType : int32_t {
+    // Use angle/height to specify the fridge goal.
+    ANGLE_HEIGHT_PROFILING = 0,
+    // Use x/y co-ordinates to specify the fridge goal.
+    X_Y_PROFILING = 1,
+  };
+
+  State state() const { return state_; }
+
+ protected:
+  void RunIteration(const control_loops::FridgeQueue::Goal *goal,
+                    const control_loops::FridgeQueue::Position *position,
+                    control_loops::FridgeQueue::Output *output,
+                    control_loops::FridgeQueue::Status *status) override;
+
+ private:
+  friend class testing::FridgeTest_DisabledGoalTest_Test;
+  friend class testing::FridgeTest_ElevatorGoalPositiveWindupTest_Test;
+  friend class testing::FridgeTest_ArmGoalPositiveWindupTest_Test;
+  friend class testing::FridgeTest_ElevatorGoalNegativeWindupTest_Test;
+  friend class testing::FridgeTest_ArmGoalNegativeWindupTest_Test;
+  friend class testing::FridgeTest_SafeArmZeroing_Test;
+
+  // Sets state_ to the correct state given the current state of the zeroing
+  // estimators.
+  void UpdateZeroingState();
+
+  void SetElevatorOffset(double left_offset, double right_offset);
+  void SetArmOffset(double left_offset, double right_offset);
+
+  // Getters for the current elevator positions.
+  double left_elevator();
+  double right_elevator();
+  double elevator();
+
+  // Getters for the current arm positions.
+  double left_arm();
+  double right_arm();
+  double arm();
+
+  // Our best guess at the current position of the elevator.
+  double estimated_left_elevator();
+  double estimated_right_elevator();
+  double estimated_elevator();
+
+  // Our best guess at the current position of the arm.
+  double estimated_left_arm();
+  double estimated_right_arm();
+  double estimated_arm();
+
+  // Returns the current zeroing velocity for either subsystem.
+  // If the subsystem is too far away from the center, these will switch
+  // directions.
+  double elevator_zeroing_velocity();
+  double arm_zeroing_velocity();
+
+  // Corrects the Observer with the current position.
+  void Correct();
+
+  double UseUnlessZero(double target_value, double default_value);
+
+  // The state feedback control loop or loops to talk to.
+  ::std::unique_ptr<CappedStateFeedbackLoop<5>> arm_loop_;
+  ::std::unique_ptr<CappedStateFeedbackLoop<4>> elevator_loop_;
+
+  zeroing::ZeroingEstimator left_arm_estimator_;
+  zeroing::ZeroingEstimator right_arm_estimator_;
+  zeroing::ZeroingEstimator left_elevator_estimator_;
+  zeroing::ZeroingEstimator right_elevator_estimator_;
+
+  // Offsets from the encoder position to the absolute position.  Add these to
+  // the encoder position to get the absolute position.
+  double left_elevator_offset_ = 0.0;
+  double right_elevator_offset_ = 0.0;
+  double left_arm_offset_ = 0.0;
+  double right_arm_offset_ = 0.0;
+
+  // Current velocity to move at while zeroing.
+  double elevator_zeroing_velocity_ = 0.0;
+  double arm_zeroing_velocity_ = 0.0;
+
+  // The goals for the elevator and arm.
+  double elevator_goal_ = 0.0;
+  double arm_goal_ = 0.0;
+
+  double arm_goal_velocity_ = 0.0;
+  double elevator_goal_velocity_ = 0.0;
+
+  State state_ = UNINITIALIZED;
+  State last_state_ = UNINITIALIZED;
+
+  control_loops::FridgeQueue::Position current_position_;
+
+  ProfilingType last_profiling_type_;
+  aos::util::ElevatorArmKinematics kinematics_;
+
+  aos::util::TrapezoidProfile arm_profile_;
+  aos::util::TrapezoidProfile elevator_profile_;
+
+  aos::util::TrapezoidProfile x_profile_;
+  aos::util::TrapezoidProfile y_profile_;
+};
+
+}  // namespace control_loops
+}  // namespace frc971
+
+#endif // Y2015_CONTROL_LOOPS_FRIDGE_H_
+
diff --git a/y2015/control_loops/fridge/fridge.q b/y2015/control_loops/fridge/fridge.q
new file mode 100644
index 0000000..257374d
--- /dev/null
+++ b/y2015/control_loops/fridge/fridge.q
@@ -0,0 +1,152 @@
+package frc971.control_loops;
+
+import "aos/common/controls/control_loops.q";
+import "frc971/control_loops/control_loops.q";
+
+// Represents states for all of the box-grabbing pistons.
+// true is grabbed and false is retracted for all of them.
+struct GrabberPistons {
+  bool top_front;
+  bool top_back;
+  bool bottom_front;
+  bool bottom_back;
+};
+
+queue_group FridgeQueue {
+  implements aos.control_loops.ControlLoop;
+
+  // All angles are in radians with 0 sticking straight up.
+  // Rotating up and into the robot (towards the back
+  // where boxes are placed) is positive. Positive output voltage moves all
+  // mechanisms in the direction with positive sensor values.
+
+  // Elevator heights are the vertical distance (in meters) from a defined zero.
+  // In this case, zero is where the portion of the carriage that Spencer
+  // removed lines up with the bolt.
+
+  // X/Y positions are distances (in meters) the fridge is away from its origin
+  // position. Origin is considered at a height of zero and an angle of zero.
+  // Positive X positions are towards the front of the robot and negative X is
+  // towards the back of the robot (which is where we score).
+  // Y is positive going up and negative when it goes below the origin.
+
+  message Goal {
+    // Profile type.
+    // Set to 0 for angle/height profiling.
+    // Set to 1 for x/y profiling.
+    int32_t profiling_type;
+
+    // Angle of the arm.
+    double angle;
+    // Height of the elevator.
+    double height;
+
+    // Angular velocity of the arm.
+    float angular_velocity;
+    // Linear velocity of the elevator.
+    float velocity;
+
+    // Maximum arm profile angular velocity or 0 for the default.
+    float max_angular_velocity;
+    // Maximum elevator profile velocity or 0 for the default.
+    float max_velocity;
+
+    // Maximum arm profile acceleration or 0 for the default.
+    float max_angular_acceleration;
+    // Maximum elevator profile acceleration or 0 for the default.
+    float max_acceleration;
+
+    // X position of the fridge.
+    double x;
+    // Y position of the fridge.
+    double y;
+
+    // Velocity of the x position of the fridge.
+    float x_velocity;
+    // Velocity of the y position of the fridge.
+    float y_velocity;
+
+    // Maximum x profile velocity or 0 for the default.
+    float max_x_velocity;
+    // Maximum y profile velocity or 0 for the default.
+    float max_y_velocity;
+
+    // Maximum x profile acceleration or 0 for the default.
+    float max_x_acceleration;
+    // Maximum y profile acceleration or 0 for the default.
+    float max_y_acceleration;
+
+    // TODO(austin): Do I need acceleration here too?
+
+    GrabberPistons grabbers;
+  };
+
+  message Position {
+    PotAndIndexPair arm;
+    PotAndIndexPair elevator;
+  };
+
+  message Status {
+    // Are both the arm and elevator zeroed?
+    bool zeroed;
+
+    // Estimated angle of the arm.
+    double angle;
+    // Estimated angular velocity of the arm.
+    float angular_velocity;
+    // Estimated height of the elevator.
+    double height;
+    // Estimated velocity of the elvator.
+    float velocity;
+    // state of the grabber pistons
+    GrabberPistons grabbers;
+
+    // Goal angle and velocity of the arm.
+    double goal_angle;
+    float goal_angular_velocity;
+    // Goal height and velocity of the elevator.
+    double goal_height;
+    float goal_velocity;
+
+    // Estimated X/Y position of the fridge.
+    // These are translated directly from the height/angle statuses.
+    double x;
+    double y;
+    float x_velocity;
+    float y_velocity;
+
+    // X/Y goals of the fridge.
+    // These are translated directly from the height/angle goals.
+    double goal_x;
+    double goal_y;
+    float goal_x_velocity;
+    float goal_y_velocity;
+
+    // If true, we have aborted.
+    bool estopped;
+
+    // The internal state of the state machine.
+    int32_t state;
+
+    EstimatorState left_elevator_state;
+    EstimatorState right_elevator_state;
+    EstimatorState left_arm_state;
+    EstimatorState right_arm_state;
+  };
+
+  message Output {
+    double left_arm;
+    double right_arm;
+    double left_elevator;
+    double right_elevator;
+
+    GrabberPistons grabbers;
+  };
+
+  queue Goal goal;
+  queue Position position;
+  queue Output output;
+  queue Status status;
+};
+
+queue_group FridgeQueue fridge_queue;
diff --git a/y2015/control_loops/fridge/fridge_lib_test.cc b/y2015/control_loops/fridge/fridge_lib_test.cc
new file mode 100644
index 0000000..7719fb4
--- /dev/null
+++ b/y2015/control_loops/fridge/fridge_lib_test.cc
@@ -0,0 +1,735 @@
+#include "y2015/control_loops/fridge/fridge.h"
+
+#include <math.h>
+#include <unistd.h>
+
+#include <memory>
+
+#include "gtest/gtest.h"
+#include "aos/common/queue.h"
+#include "aos/common/time.h"
+#include "aos/common/commonmath.h"
+#include "aos/common/controls/control_loop_test.h"
+#include "y2015/util/kinematics.h"
+#include "frc971/control_loops/position_sensor_sim.h"
+#include "y2015/control_loops/fridge/arm_motor_plant.h"
+#include "y2015/control_loops/fridge/elevator_motor_plant.h"
+#include "y2015/control_loops/fridge/fridge.q.h"
+#include "y2015/constants.h"
+#include "frc971/control_loops/team_number_test_environment.h"
+
+using ::aos::time::Time;
+
+namespace frc971 {
+namespace control_loops {
+namespace testing {
+// Class which simulates the fridge and sends out queue messages with the
+// position.
+class FridgeSimulation {
+ public:
+  static constexpr double kNoiseScalar = 0.1;
+  // Constructs a simulation.
+  FridgeSimulation()
+      : arm_plant_(new StateFeedbackPlant<4, 2, 2>(MakeArmPlant())),
+        elevator_plant_(new StateFeedbackPlant<4, 2, 2>(MakeElevatorPlant())),
+        left_arm_pot_encoder_(
+            constants::GetValues().fridge.left_arm_zeroing.index_difference),
+        right_arm_pot_encoder_(
+            constants::GetValues().fridge.right_arm_zeroing.index_difference),
+        left_elevator_pot_encoder_(
+            constants::GetValues().fridge.left_elev_zeroing.index_difference),
+        right_elevator_pot_encoder_(
+            constants::GetValues().fridge.right_elev_zeroing.index_difference),
+        fridge_queue_(".frc971.control_loops.fridge_queue", 0xe4e05855,
+                      ".frc971.control_loops.fridge_queue.goal",
+                      ".frc971.control_loops.fridge_queue.position",
+                      ".frc971.control_loops.fridge_queue.output",
+                      ".frc971.control_loops.fridge_queue.status") {
+    // Initialize the elevator.
+    InitializeElevatorPosition(
+        constants::GetValues().fridge.elevator.lower_limit);
+    // Initialize the arm.
+    InitializeArmPosition(0.0);
+  }
+
+  void InitializeElevatorPosition(double start_pos) {
+    InitializeElevatorPosition(start_pos, start_pos);
+  }
+
+  void InitializeElevatorPosition(double left_start_pos,
+                                  double right_start_pos) {
+    InitializeElevatorPosition(
+        left_start_pos, right_start_pos,
+        kNoiseScalar *
+            constants::GetValues().fridge.right_elev_zeroing.index_difference);
+  }
+
+  void InitializeElevatorPosition(double left_start_pos, double right_start_pos,
+                                  double pot_noise_stddev) {
+    // Update the internal state of the elevator plant.
+    elevator_plant_->mutable_X(0, 0) = (left_start_pos + right_start_pos) / 2.0;
+    elevator_plant_->mutable_X(1, 0) = 0.0;
+    elevator_plant_->mutable_X(2, 0) = (left_start_pos - right_start_pos) / 2.0;
+    elevator_plant_->mutable_X(3, 0) = 0.0;
+
+    right_elevator_pot_encoder_.Initialize(right_start_pos, pot_noise_stddev);
+    left_elevator_pot_encoder_.Initialize(left_start_pos, pot_noise_stddev);
+    elevator_initial_difference_ = left_start_pos - right_start_pos;
+  }
+
+  void InitializeArmPosition(double start_pos) {
+    InitializeArmPosition(start_pos, start_pos);
+  }
+
+  void InitializeArmPosition(double left_start_pos, double right_start_pos) {
+    InitializeArmPosition(
+        left_start_pos, right_start_pos,
+        kNoiseScalar *
+            constants::GetValues().fridge.right_arm_zeroing.index_difference);
+  }
+  void InitializeArmPosition(double left_start_pos, double right_start_pos,
+                             double pot_noise_stddev) {
+    // Update the internal state of the arm plant.
+    arm_plant_->mutable_X(0, 0) = (left_start_pos + right_start_pos) / 2.0;
+    arm_plant_->mutable_X(1, 0) = 0.0;
+    arm_plant_->mutable_X(2, 0) = (left_start_pos - right_start_pos) / 2.0;
+    arm_plant_->mutable_X(3, 0) = 0.0;
+
+    left_arm_pot_encoder_.Initialize(left_start_pos, pot_noise_stddev);
+    right_arm_pot_encoder_.Initialize(right_start_pos, pot_noise_stddev);
+    arm_initial_difference_ = left_start_pos - right_start_pos;
+  }
+
+  // Changes the left-right calculations in the limit checks to measure absolute
+  // differences instead of differences relative to the starting offset.
+  void ErrorOnAbsoluteDifference() {
+    arm_initial_difference_ = 0.0;
+    elevator_initial_difference_ = 0.0;
+  }
+
+  // Sends a queue message with the position.
+  void SendPositionMessage() {
+    ::aos::ScopedMessagePtr<control_loops::FridgeQueue::Position> position =
+        fridge_queue_.position.MakeMessage();
+
+    left_arm_pot_encoder_.GetSensorValues(&position->arm.left);
+    right_arm_pot_encoder_.GetSensorValues(&position->arm.right);
+    left_elevator_pot_encoder_.GetSensorValues(&position->elevator.left);
+    right_elevator_pot_encoder_.GetSensorValues(&position->elevator.right);
+
+    position.Send();
+  }
+
+  // Sets the difference between the commanded and applied power for the arm.
+  // This lets us test that the integrator for the arm works.
+  void set_arm_power_error(double arm_power_error) {
+    arm_power_error_ = arm_power_error;
+  }
+  // Simulates for a single timestep.
+  void Simulate() {
+    EXPECT_TRUE(fridge_queue_.output.FetchLatest());
+
+    // Feed voltages into physics simulation.
+    if (arm_power_error_ != 0.0) {
+      arm_plant_->mutable_U() << ::aos::Clip(
+          fridge_queue_.output->left_arm + arm_power_error_, -12, 12),
+          ::aos::Clip(fridge_queue_.output->right_arm + arm_power_error_, -12,
+                      12);
+    } else {
+      arm_plant_->mutable_U() << fridge_queue_.output->left_arm,
+          fridge_queue_.output->right_arm;
+    }
+    elevator_plant_->mutable_U() << fridge_queue_.output->left_elevator,
+        fridge_queue_.output->right_elevator;
+
+    // Use the plant to generate the next physical state given the voltages to
+    // the motors.
+    arm_plant_->Update();
+    elevator_plant_->Update();
+
+    const double left_arm_angle = arm_plant_->Y(0, 0);
+    const double right_arm_angle = arm_plant_->Y(1, 0);
+    const double left_elevator_height = elevator_plant_->Y(0, 0);
+    const double right_elevator_height = elevator_plant_->Y(1, 0);
+
+    // TODO (phil) Do some sanity tests on the arm angles and the elevator
+    // heights. For example, we need to make sure that both sides are within a
+    // certain distance of each other and they haven't crashed into the top or
+    // the bottom.
+
+    // Use the physical state to simulate sensor readings.
+    left_arm_pot_encoder_.MoveTo(left_arm_angle);
+    right_arm_pot_encoder_.MoveTo(right_arm_angle);
+    left_elevator_pot_encoder_.MoveTo(left_elevator_height);
+    right_elevator_pot_encoder_.MoveTo(right_elevator_height);
+
+    // Verify that the arm and elevator sides don't change much from their
+    // initial difference.  Use the initial difference instead of the absolute
+    // difference to handle starting too far apart to test e-stopping.
+    EXPECT_NEAR(left_arm_angle - right_arm_angle, arm_initial_difference_,
+                5.0 * M_PI / 180.0);
+    EXPECT_NEAR(left_elevator_height - right_elevator_height,
+                elevator_initial_difference_, 0.0254);
+
+    // Validate that the arm is within range.
+    EXPECT_GE(left_arm_angle,
+              constants::GetValues().fridge.arm.lower_hard_limit);
+    EXPECT_GE(right_arm_angle,
+              constants::GetValues().fridge.arm.lower_hard_limit);
+    EXPECT_LE(left_arm_angle,
+              constants::GetValues().fridge.arm.upper_hard_limit);
+    EXPECT_LE(right_arm_angle,
+              constants::GetValues().fridge.arm.upper_hard_limit);
+
+    // Validate that the elevator is within range.
+    EXPECT_GE(left_elevator_height,
+              constants::GetValues().fridge.elevator.lower_hard_limit);
+    EXPECT_GE(right_elevator_height,
+              constants::GetValues().fridge.elevator.lower_hard_limit);
+    EXPECT_LE(left_elevator_height,
+              constants::GetValues().fridge.elevator.upper_hard_limit);
+    EXPECT_LE(right_elevator_height,
+              constants::GetValues().fridge.elevator.upper_hard_limit);
+  }
+
+ private:
+  ::std::unique_ptr<StateFeedbackPlant<4, 2, 2>> arm_plant_;
+  ::std::unique_ptr<StateFeedbackPlant<4, 2, 2>> elevator_plant_;
+
+  PositionSensorSimulator left_arm_pot_encoder_;
+  PositionSensorSimulator right_arm_pot_encoder_;
+  PositionSensorSimulator left_elevator_pot_encoder_;
+  PositionSensorSimulator right_elevator_pot_encoder_;
+
+  FridgeQueue fridge_queue_;
+
+  double elevator_initial_difference_ = 0.0;
+  double arm_initial_difference_ = 0.0;
+  double arm_power_error_ = 0.0;
+};
+
+class FridgeTest : public ::aos::testing::ControlLoopTest {
+ protected:
+  FridgeTest()
+      : fridge_queue_(".frc971.control_loops.fridge_queue", 0xe4e05855,
+                      ".frc971.control_loops.fridge_queue.goal",
+                      ".frc971.control_loops.fridge_queue.position",
+                      ".frc971.control_loops.fridge_queue.output",
+                      ".frc971.control_loops.fridge_queue.status"),
+        fridge_(&fridge_queue_),
+        fridge_plant_(),
+        kinematics_(constants::GetValues().fridge.arm_length,
+                    constants::GetValues().fridge.elevator.upper_limit,
+                    constants::GetValues().fridge.elevator.lower_limit,
+                    constants::GetValues().fridge.arm.upper_limit,
+                    constants::GetValues().fridge.arm.lower_limit) {
+    set_team_id(kTeamNumber);
+  }
+
+  void VerifyNearGoal() {
+    fridge_queue_.goal.FetchLatest();
+    fridge_queue_.status.FetchLatest();
+    EXPECT_TRUE(fridge_queue_.goal.get() != nullptr);
+    EXPECT_TRUE(fridge_queue_.status.get() != nullptr);
+    if (fridge_queue_.goal->profiling_type == 0) {
+      EXPECT_NEAR(fridge_queue_.goal->angle, fridge_queue_.status->angle,
+                  0.001);
+      EXPECT_NEAR(fridge_queue_.goal->height, fridge_queue_.status->height,
+                  0.001);
+    } else if (fridge_queue_.goal->profiling_type == 1) {
+      aos::util::ElevatorArmKinematics::KinematicResult x_y_status;
+      kinematics_.ForwardKinematic(fridge_queue_.status->height,
+                                   fridge_queue_.status->angle, 0.0, 0.0, &x_y_status);
+      EXPECT_NEAR(fridge_queue_.goal->x, x_y_status.fridge_x, 0.001);
+      EXPECT_NEAR(fridge_queue_.goal->y, x_y_status.fridge_h, 0.001);
+    } else {
+      // Unhandled profiling type.
+      EXPECT_TRUE(false);
+    }
+  }
+
+  // Runs one iteration of the whole simulation and checks that separation
+  // remains reasonable.
+  void RunIteration(bool enabled = true) {
+    SendMessages(enabled);
+
+    fridge_plant_.SendPositionMessage();
+    fridge_.Iterate();
+    fridge_plant_.Simulate();
+
+    TickTime();
+  }
+
+  // Runs iterations until the specified amount of simulated time has elapsed.
+  void RunForTime(const Time &run_for, bool enabled = true) {
+    const auto start_time = Time::Now();
+    while (Time::Now() < start_time + run_for) {
+      RunIteration(enabled);
+    }
+  }
+
+  // Create a new instance of the test queue so that it invalidates the queue
+  // that it points to.  Otherwise, we will have a pointed to
+  // shared memory that is no longer valid.
+  FridgeQueue fridge_queue_;
+
+  // Create a control loop and simulation.
+  Fridge fridge_;
+  FridgeSimulation fridge_plant_;
+
+  aos::util::ElevatorArmKinematics kinematics_;
+};
+
+// Tests that the loop does nothing when the goal is zero.
+TEST_F(FridgeTest, DoesNothing) {
+  // Set the goals to the starting values. This should theoretically guarantee
+  // that the controller does nothing.
+  const auto &values = constants::GetValues();
+  ASSERT_TRUE(fridge_queue_.goal.MakeWithBuilder()
+                  .angle(0.0)
+                  .height(values.fridge.elevator.lower_limit)
+                  .max_velocity(20)
+                  .max_acceleration(20)
+                  .max_angular_velocity(20)
+                  .max_angular_acceleration(20)
+                  .Send());
+
+  // Run a few iterations.
+  RunForTime(Time::InSeconds(5));
+
+  VerifyNearGoal();
+}
+
+// Tests that the loop can reach a goal.
+TEST_F(FridgeTest, ReachesXYGoal) {
+  // Set a reasonable goal.
+  const auto &values = constants::GetValues();
+  const double soft_limit = values.fridge.elevator.lower_limit;
+  const double height = soft_limit + 0.4;
+  const double angle = M_PI / 6.0;
+
+  aos::util::ElevatorArmKinematics::KinematicResult x_y_goals;
+  kinematics_.ForwardKinematic(height, angle, 0.0, 0.0, &x_y_goals);
+
+  ASSERT_TRUE(fridge_queue_.goal.MakeWithBuilder()
+                  .profiling_type(1)
+                  .x(x_y_goals.fridge_x)
+                  .y(x_y_goals.fridge_h)
+                  .max_x_velocity(20)
+                  .max_y_velocity(20)
+                  .max_x_acceleration(20)
+                  .max_y_acceleration(20)
+                  .Send());
+
+  // Give it a lot of time to get there.
+  RunForTime(Time::InSeconds(5));
+
+  VerifyNearGoal();
+}
+
+// Tests that the loop can reach a goal.
+TEST_F(FridgeTest, ReachesGoal) {
+  // Set a reasonable goal.
+  const auto &values = constants::GetValues();
+  const double soft_limit = values.fridge.elevator.lower_limit;
+  ASSERT_TRUE(fridge_queue_.goal.MakeWithBuilder()
+                  .angle(M_PI / 4.0)
+                  .height(soft_limit + 0.5)
+                  .max_velocity(20)
+                  .max_acceleration(20)
+                  .max_angular_velocity(20)
+                  .max_angular_acceleration(20)
+                  .Send());
+
+  // Give it a lot of time to get there.
+  RunForTime(Time::InSeconds(5));
+
+  VerifyNearGoal();
+}
+
+// Tests that the loop doesn't try and go beyond the physical range of the
+// mechanisms.
+TEST_F(FridgeTest, RespectsRange) {
+  // Put the arm up to get it out of the way.
+  // We're going to send the elevator to -5, which should be significantly too
+  // low.
+  ASSERT_TRUE(fridge_queue_.goal.MakeWithBuilder()
+                  .angle(M_PI)
+                  .height(-5.0)
+                  .max_velocity(20)
+                  .max_acceleration(20)
+                  .max_angular_velocity(20)
+                  .max_angular_acceleration(20)
+                  .Send());
+
+  RunForTime(Time::InSeconds(10));
+
+  // Check that we are near our soft limit.
+  fridge_queue_.status.FetchLatest();
+  const auto &values = constants::GetValues();
+  EXPECT_NEAR(values.fridge.elevator.lower_limit, fridge_queue_.status->height,
+              0.001);
+  EXPECT_NEAR(values.fridge.arm.upper_limit, fridge_queue_.status->angle,
+              0.001);
+
+  // Put the arm down to get it out of the way.
+  // We're going to give the elevator some ridiculously high goal.
+  ASSERT_TRUE(fridge_queue_.goal.MakeWithBuilder()
+                  .angle(-M_PI)
+                  .height(50.0)
+                  .max_velocity(20)
+                  .max_acceleration(20)
+                  .max_angular_velocity(20)
+                  .max_angular_acceleration(20)
+                  .Send());
+
+  RunForTime(Time::InSeconds(10));
+
+  // Check that we are near our soft limit.
+  fridge_queue_.status.FetchLatest();
+  EXPECT_NEAR(values.fridge.elevator.upper_limit, fridge_queue_.status->height,
+              0.001);
+  EXPECT_NEAR(values.fridge.arm.lower_limit, fridge_queue_.status->angle,
+              0.001);
+}
+
+// Tests that the loop zeroes when run for a while.
+TEST_F(FridgeTest, ZeroTest) {
+  fridge_queue_.goal.MakeWithBuilder()
+      .angle(0.0)
+      .height(0.5)
+      .max_velocity(20)
+      .max_acceleration(20)
+      .max_angular_velocity(20)
+      .max_angular_acceleration(20)
+      .Send();
+  RunForTime(Time::InSeconds(5));
+
+  VerifyNearGoal();
+}
+
+// Tests that starting at the lower hardstops doesn't cause an abort.
+TEST_F(FridgeTest, LowerHardstopStartup) {
+  fridge_plant_.InitializeElevatorPosition(
+      constants::GetValues().fridge.elevator.lower_hard_limit,
+      constants::GetValues().fridge.elevator.lower_hard_limit);
+  fridge_plant_.InitializeArmPosition(
+      constants::GetValues().fridge.arm.lower_hard_limit,
+      constants::GetValues().fridge.arm.lower_hard_limit);
+  fridge_queue_.goal.MakeWithBuilder().angle(0.0).height(0.4).Send();
+  // We have to wait for it to put the elevator in a safe position as well.
+  RunForTime(Time::InMS(8000));
+
+  VerifyNearGoal();
+}
+
+// Tests that starting at the upper hardstops doesn't cause an abort.
+TEST_F(FridgeTest, UpperHardstopStartup) {
+  fridge_plant_.InitializeElevatorPosition(
+      constants::GetValues().fridge.elevator.upper_hard_limit,
+      constants::GetValues().fridge.elevator.upper_hard_limit);
+  fridge_plant_.InitializeArmPosition(
+      constants::GetValues().fridge.arm.upper_hard_limit,
+      constants::GetValues().fridge.arm.upper_hard_limit);
+  fridge_queue_.goal.MakeWithBuilder().angle(0.0).height(0.4).Send();
+  RunForTime(Time::InMS(5000));
+
+  VerifyNearGoal();
+}
+
+// Tests that starting with an initial arm difference triggers an ESTOP.
+TEST_F(FridgeTest, ArmFarApartEstop) {
+  fridge_queue_.goal.MakeWithBuilder().angle(0.0).height(0.4).Send();
+
+  do {
+    fridge_plant_.InitializeArmPosition(
+        constants::GetValues().fridge.arm.lower_limit,
+        constants::GetValues().fridge.arm.lower_limit + 0.2);
+    SendMessages(true);
+    fridge_plant_.SendPositionMessage();
+    fridge_.Iterate();
+    fridge_plant_.Simulate();
+    TickTime();
+  } while (fridge_.state() == Fridge::INITIALIZING);
+
+  EXPECT_EQ(Fridge::ZEROING_ELEVATOR, fridge_.state());
+
+  // TODO(austin): We should estop earlier once Phil's code to detect issues
+  // before the index pulse is merged.
+  while (fridge_.state() != Fridge::RUNNING &&
+         fridge_.state() != Fridge::ESTOP) {
+    SendMessages(true);
+    fridge_plant_.SendPositionMessage();
+    fridge_.Iterate();
+    fridge_plant_.Simulate();
+    TickTime();
+  }
+
+  EXPECT_EQ(Fridge::ESTOP, fridge_.state());
+}
+
+// Tests that starting with an initial elevator difference triggers an ESTOP.
+TEST_F(FridgeTest, ElevatorFarApartEstop) {
+  fridge_queue_.goal.MakeWithBuilder().angle(0.0).height(0.4).Send();
+
+  do {
+    fridge_plant_.InitializeElevatorPosition(
+        constants::GetValues().fridge.elevator.lower_limit,
+        constants::GetValues().fridge.elevator.lower_limit + 0.1);
+    SendMessages(true);
+    fridge_plant_.SendPositionMessage();
+    fridge_.Iterate();
+    fridge_plant_.Simulate();
+    TickTime();
+  } while (fridge_.state() == Fridge::INITIALIZING);
+
+  EXPECT_EQ(Fridge::ZEROING_ELEVATOR, fridge_.state());
+
+  // TODO(austin): We should estop earlier once Phil's code to detect issues
+  // before the index pulse is merged.
+  while (fridge_.state() != Fridge::RUNNING &&
+         fridge_.state() != Fridge::ESTOP) {
+    SendMessages(true);
+    fridge_plant_.SendPositionMessage();
+    fridge_.Iterate();
+    fridge_plant_.Simulate();
+    TickTime();
+  }
+
+  EXPECT_EQ(Fridge::ESTOP, fridge_.state());
+}
+
+// Tests that starting with an initial elevator difference converges back to 0
+// error when zeroed.
+TEST_F(FridgeTest, ElevatorFixError) {
+  fridge_queue_.goal.MakeWithBuilder()
+      .angle(0.0)
+      .height(0.2)
+      .max_velocity(20)
+      .max_acceleration(20)
+      .Send();
+
+  do {
+    fridge_plant_.InitializeElevatorPosition(
+        constants::GetValues().fridge.elevator.lower_limit,
+        constants::GetValues().fridge.elevator.lower_limit + 0.01);
+    fridge_plant_.ErrorOnAbsoluteDifference();
+    SendMessages(true);
+    fridge_plant_.SendPositionMessage();
+    fridge_.Iterate();
+    fridge_plant_.Simulate();
+    TickTime();
+  } while (fridge_.state() == Fridge::INITIALIZING);
+
+  EXPECT_EQ(Fridge::ZEROING_ELEVATOR, fridge_.state());
+
+  RunForTime(Time::InSeconds(5));
+  VerifyNearGoal();
+}
+
+// Tests that starting with an initial arm difference converges back to 0
+// error when zeroed.
+TEST_F(FridgeTest, ArmFixError) {
+  fridge_queue_.goal.MakeWithBuilder()
+      .angle(0.0)
+      .height(0.2)
+      .max_angular_velocity(20)
+      .max_angular_acceleration(20)
+      .Send();
+
+  do {
+    fridge_plant_.InitializeArmPosition(0.0, 0.02);
+    fridge_plant_.ErrorOnAbsoluteDifference();
+    SendMessages(true);
+    fridge_plant_.SendPositionMessage();
+    fridge_.Iterate();
+    fridge_plant_.Simulate();
+    TickTime();
+  } while (fridge_.state() == Fridge::INITIALIZING);
+
+  EXPECT_EQ(Fridge::ZEROING_ELEVATOR, fridge_.state());
+
+  RunForTime(Time::InSeconds(5));
+  VerifyNearGoal();
+}
+
+// Tests that resetting WPILib results in a rezero.
+TEST_F(FridgeTest, ResetTest) {
+  fridge_plant_.InitializeElevatorPosition(
+      constants::GetValues().fridge.elevator.upper_hard_limit,
+      constants::GetValues().fridge.elevator.upper_hard_limit);
+  fridge_plant_.InitializeArmPosition(
+      constants::GetValues().fridge.arm.upper_hard_limit,
+      constants::GetValues().fridge.arm.upper_hard_limit);
+  fridge_queue_.goal.MakeWithBuilder().angle(0.03).height(0.45).Send();
+  RunForTime(Time::InMS(5000));
+
+  EXPECT_EQ(Fridge::RUNNING, fridge_.state());
+  VerifyNearGoal();
+  SimulateSensorReset();
+  RunForTime(Time::InMS(100));
+  EXPECT_NE(Fridge::RUNNING, fridge_.state());
+  RunForTime(Time::InMS(6000));
+  EXPECT_EQ(Fridge::RUNNING, fridge_.state());
+  VerifyNearGoal();
+}
+
+// Tests that the internal goals don't change while disabled.
+TEST_F(FridgeTest, DisabledGoalTest) {
+  fridge_queue_.goal.MakeWithBuilder().angle(0.03).height(0.45).Send();
+
+  RunForTime(Time::InMS(100), false);
+  EXPECT_EQ(0.0, fridge_.elevator_goal_);
+  EXPECT_EQ(0.0, fridge_.arm_goal_);
+
+  // Now make sure they move correctly
+  RunForTime(Time::InMS(4000), true);
+  EXPECT_NE(0.0, fridge_.elevator_goal_);
+  EXPECT_NE(0.0, fridge_.arm_goal_);
+}
+
+// Tests that the elevator zeroing goals don't wind up too far.
+TEST_F(FridgeTest, ElevatorGoalPositiveWindupTest) {
+  fridge_queue_.goal.MakeWithBuilder().angle(0.03).height(0.45).Send();
+
+  while (fridge_.state() != Fridge::ZEROING_ELEVATOR) {
+    RunIteration();
+  }
+
+  // Kick it.
+  RunForTime(Time::InMS(50));
+  double orig_fridge_goal = fridge_.elevator_goal_;
+  fridge_.elevator_goal_ += 100.0;
+
+  RunIteration();
+  EXPECT_NEAR(orig_fridge_goal, fridge_.elevator_goal_, 0.05);
+
+  RunIteration();
+
+  EXPECT_EQ(fridge_.elevator_loop_->U(), fridge_.elevator_loop_->U_uncapped());
+}
+
+// Tests that the arm zeroing goals don't wind up too far.
+TEST_F(FridgeTest, ArmGoalPositiveWindupTest) {
+  fridge_queue_.goal.MakeWithBuilder().angle(0.03).height(0.45).Send();
+
+  int i = 0;
+  while (fridge_.state() != Fridge::ZEROING_ARM) {
+    RunIteration();
+    ++i;
+    ASSERT_LE(i, 10000);
+  }
+
+  // Kick it.
+  RunForTime(Time::InMS(50));
+  double orig_fridge_goal = fridge_.arm_goal_;
+  fridge_.arm_goal_ += 100.0;
+
+  RunIteration();
+  EXPECT_NEAR(orig_fridge_goal, fridge_.arm_goal_, 0.05);
+
+  RunIteration();
+
+  EXPECT_EQ(fridge_.arm_loop_->U(), fridge_.arm_loop_->U_uncapped());
+}
+
+// Tests that the elevator zeroing goals don't wind up too far.
+TEST_F(FridgeTest, ElevatorGoalNegativeWindupTest) {
+  fridge_queue_.goal.MakeWithBuilder().angle(0.03).height(0.45).Send();
+
+  while (fridge_.state() != Fridge::ZEROING_ELEVATOR) {
+    RunIteration();
+  }
+
+  // Kick it.
+  RunForTime(Time::InMS(50));
+  double orig_fridge_goal = fridge_.elevator_goal_;
+  fridge_.elevator_goal_ -= 100.0;
+
+  RunIteration();
+  EXPECT_NEAR(orig_fridge_goal, fridge_.elevator_goal_, 0.05);
+
+  RunIteration();
+
+  EXPECT_EQ(fridge_.elevator_loop_->U(), fridge_.elevator_loop_->U_uncapped());
+}
+
+// Tests that the arm zeroing goals don't wind up too far.
+TEST_F(FridgeTest, ArmGoalNegativeWindupTest) {
+  fridge_queue_.goal.MakeWithBuilder().angle(0.03).height(0.45).Send();
+
+  while (fridge_.state() != Fridge::ZEROING_ARM) {
+    RunIteration();
+  }
+
+  // Kick it.
+  RunForTime(Time::InMS(50));
+  double orig_fridge_goal = fridge_.arm_goal_;
+  fridge_.arm_goal_ -= 100.0;
+
+  RunIteration();
+  EXPECT_NEAR(orig_fridge_goal, fridge_.arm_goal_, 0.05);
+
+  RunIteration();
+
+  EXPECT_EQ(fridge_.arm_loop_->U(), fridge_.arm_loop_->U_uncapped());
+}
+
+// Tests that the loop zeroes when run for a while.
+TEST_F(FridgeTest, ZeroNoGoal) {
+  RunForTime(Time::InSeconds(5));
+
+  EXPECT_EQ(Fridge::RUNNING, fridge_.state());
+}
+
+// Tests that if we start at the bottom, the elevator moves to a safe height
+// before zeroing the arm.
+TEST_F(FridgeTest, SafeArmZeroing) {
+  auto &values = constants::GetValues();
+  fridge_plant_.InitializeElevatorPosition(
+      values.fridge.elevator.lower_hard_limit);
+  fridge_plant_.InitializeArmPosition(M_PI / 4.0);
+
+  const auto start_time = Time::Now();
+  double last_arm_goal = fridge_.arm_goal_;
+  while (Time::Now() < start_time + Time::InMS(4000)) {
+    RunIteration();
+
+    if (fridge_.state() != Fridge::ZEROING_ELEVATOR) {
+      // Wait until we are zeroing the elevator.
+      continue;
+    }
+
+    fridge_queue_.status.FetchLatest();
+    ASSERT_TRUE(fridge_queue_.status.get() != nullptr);
+    if (fridge_queue_.status->height > values.fridge.arm_zeroing_height) {
+      // We had better not be trying to zero the arm...
+      EXPECT_EQ(last_arm_goal, fridge_.arm_goal_);
+      last_arm_goal = fridge_.arm_goal_;
+    }
+  }
+}
+
+// Tests that the arm integrator works.
+TEST_F(FridgeTest, ArmIntegratorTest) {
+  fridge_plant_.InitializeArmPosition(
+      (constants::GetValues().fridge.arm.lower_hard_limit +
+       constants::GetValues().fridge.arm.lower_hard_limit) /
+      2.0);
+  fridge_plant_.set_arm_power_error(1.0);
+  fridge_queue_.goal.MakeWithBuilder().angle(0.0).height(0.4).Send();
+
+  RunForTime(Time::InMS(8000));
+
+  VerifyNearGoal();
+}
+
+// Phil:
+// TODO(austin): Check that we e-stop if encoder index pulse is not n
+// revolutions away from last one. (got extra counts from noise, etc).
+// TODO(austin): Check that we e-stop if pot disagrees too much with encoder
+// after we are zeroed.
+
+}  // namespace testing
+}  // namespace control_loops
+}  // namespace frc971
diff --git a/y2015/control_loops/fridge/fridge_main.cc b/y2015/control_loops/fridge/fridge_main.cc
new file mode 100644
index 0000000..e0fd6ea
--- /dev/null
+++ b/y2015/control_loops/fridge/fridge_main.cc
@@ -0,0 +1,11 @@
+#include "y2015/control_loops/fridge/fridge.h"
+
+#include "aos/linux_code/init.h"
+
+int main() {
+  ::aos::Init();
+  frc971::control_loops::Fridge fridge;
+  fridge.Run();
+  ::aos::Cleanup();
+  return 0;
+}
diff --git a/y2015/control_loops/fridge/integral_arm_plant.cc b/y2015/control_loops/fridge/integral_arm_plant.cc
new file mode 100644
index 0000000..da269d7
--- /dev/null
+++ b/y2015/control_loops/fridge/integral_arm_plant.cc
@@ -0,0 +1,49 @@
+#include "y2015/control_loops/fridge/integral_arm_plant.h"
+
+#include <vector>
+
+#include "frc971/control_loops/state_feedback_loop.h"
+
+namespace frc971 {
+namespace control_loops {
+
+StateFeedbackPlantCoefficients<5, 2, 2> MakeIntegralArmPlantCoefficients() {
+  Eigen::Matrix<double, 5, 5> A;
+  A << 1.0, 0.00479642025454, 0.0, 0.0, 4.92993559969e-05, 0.0, 0.919688585028, 0.0, 0.0, 0.0194484035162, 0.0, 0.0, 0.999539771613, 0.00479566382645, 0.0, 0.0, 0.0, -0.18154390621, 0.919241022297, 0.0, 0.0, 0.0, 0.0, 0.0, 1.0;
+  Eigen::Matrix<double, 5, 2> B;
+  B << 2.46496779984e-05, 2.46496779984e-05, 0.00972420175808, 0.00972420175808, 2.46477449538e-05, -2.46477449538e-05, 0.00972266818532, -0.00972266818532, 0.0, 0.0;
+  Eigen::Matrix<double, 2, 5> C;
+  C << 1.0, 0.0, 1.0, 0.0, 0.0, 1.0, 0.0, -1.0, 0.0, 0.0;
+  Eigen::Matrix<double, 2, 2> D;
+  D << 0, 0, 0, 0;
+  Eigen::Matrix<double, 2, 1> U_max;
+  U_max << 12.0, 12.0;
+  Eigen::Matrix<double, 2, 1> U_min;
+  U_min << -12.0, -12.0;
+  return StateFeedbackPlantCoefficients<5, 2, 2>(A, B, C, D, U_max, U_min);
+}
+
+StateFeedbackController<5, 2, 2> MakeIntegralArmController() {
+  Eigen::Matrix<double, 5, 2> L;
+  L << 0.461805946837, 0.461805946837, 5.83483983392, 5.83483983392, 0.429725467802, -0.429725467802, 0.18044816586, -0.18044816586, 31.0623964848, 31.0623964848;
+  Eigen::Matrix<double, 2, 5> K;
+  K << 320.979606093, 21.0129517955, 884.233784759, 36.3637782119, 1.0, 320.979606095, 21.0129517956, -884.233784749, -36.3637782119, 1.0;
+  Eigen::Matrix<double, 5, 5> A_inv;
+  A_inv << 1.0, -0.00521526561559, 0.0, 0.0, 5.21292341391e-05, 0.0, 1.08732457517, 0.0, 0.0, -0.0211467270909, 0.0, 0.0, 0.999513354044, -0.00521444313273, 0.0, 0.0, 0.0, 0.197397150694, 1.08682415753, 0.0, 0.0, 0.0, 0.0, 0.0, 1.0;
+  return StateFeedbackController<5, 2, 2>(L, K, A_inv, MakeIntegralArmPlantCoefficients());
+}
+
+StateFeedbackPlant<5, 2, 2> MakeIntegralArmPlant() {
+  ::std::vector< ::std::unique_ptr<StateFeedbackPlantCoefficients<5, 2, 2>>> plants(1);
+  plants[0] = ::std::unique_ptr<StateFeedbackPlantCoefficients<5, 2, 2>>(new StateFeedbackPlantCoefficients<5, 2, 2>(MakeIntegralArmPlantCoefficients()));
+  return StateFeedbackPlant<5, 2, 2>(&plants);
+}
+
+StateFeedbackLoop<5, 2, 2> MakeIntegralArmLoop() {
+  ::std::vector< ::std::unique_ptr<StateFeedbackController<5, 2, 2>>> controllers(1);
+  controllers[0] = ::std::unique_ptr<StateFeedbackController<5, 2, 2>>(new StateFeedbackController<5, 2, 2>(MakeIntegralArmController()));
+  return StateFeedbackLoop<5, 2, 2>(&controllers);
+}
+
+}  // namespace control_loops
+}  // namespace frc971
diff --git a/y2015/control_loops/fridge/integral_arm_plant.h b/y2015/control_loops/fridge/integral_arm_plant.h
new file mode 100644
index 0000000..80a4876
--- /dev/null
+++ b/y2015/control_loops/fridge/integral_arm_plant.h
@@ -0,0 +1,20 @@
+#ifndef Y2015_CONTROL_LOOPS_FRIDGE_INTEGRAL_ARM_PLANT_H_
+#define Y2015_CONTROL_LOOPS_FRIDGE_INTEGRAL_ARM_PLANT_H_
+
+#include "frc971/control_loops/state_feedback_loop.h"
+
+namespace frc971 {
+namespace control_loops {
+
+StateFeedbackPlantCoefficients<5, 2, 2> MakeIntegralArmPlantCoefficients();
+
+StateFeedbackController<5, 2, 2> MakeIntegralArmController();
+
+StateFeedbackPlant<5, 2, 2> MakeIntegralArmPlant();
+
+StateFeedbackLoop<5, 2, 2> MakeIntegralArmLoop();
+
+}  // namespace control_loops
+}  // namespace frc971
+
+#endif  // Y2015_CONTROL_LOOPS_FRIDGE_INTEGRAL_ARM_PLANT_H_
diff --git a/y2015/control_loops/fridge/replay_fridge.cc b/y2015/control_loops/fridge/replay_fridge.cc
new file mode 100644
index 0000000..65cc98a
--- /dev/null
+++ b/y2015/control_loops/fridge/replay_fridge.cc
@@ -0,0 +1,24 @@
+#include "aos/common/controls/replay_control_loop.h"
+#include "aos/linux_code/init.h"
+
+#include "y2015/control_loops/fridge/fridge.q.h"
+
+// Reads one or more log files and sends out all the queue messages (in the
+// correct order and at the correct time) to feed a "live" fridge process.
+
+int main(int argc, char **argv) {
+  if (argc <= 1) {
+    fprintf(stderr, "Need at least one file to replay!\n");
+    return EXIT_FAILURE;
+  }
+
+  ::aos::InitNRT();
+
+  ::aos::controls::ControlLoopReplayer<::frc971::control_loops::FridgeQueue>
+      replayer(&::frc971::control_loops::fridge_queue, "fridge");
+  for (int i = 1; i < argc; ++i) {
+    replayer.ProcessFile(argv[i]);
+  }
+
+  ::aos::Cleanup();
+}
diff --git a/y2015/control_loops/python/arm.py b/y2015/control_loops/python/arm.py
new file mode 100755
index 0000000..e17990a
--- /dev/null
+++ b/y2015/control_loops/python/arm.py
@@ -0,0 +1,409 @@
+#!/usr/bin/python
+
+import control_loop
+import controls
+import polytope
+import polydrivetrain
+import numpy
+import math
+import sys
+import matplotlib
+from matplotlib import pylab
+
+
+class Arm(control_loop.ControlLoop):
+  def __init__(self, name="Arm", mass=None):
+    super(Arm, self).__init__(name)
+    # Stall Torque in N m
+    self.stall_torque = 0.476
+    # Stall Current in Amps
+    self.stall_current = 80.730
+    # Free Speed in RPM
+    self.free_speed = 13906.0
+    # Free Current in Amps
+    self.free_current = 5.820
+    # Mass of the arm
+    if mass is None:
+      self.mass = 13.0
+    else:
+      self.mass = mass
+
+    # Resistance of the motor
+    self.R = 12.0 / self.stall_current
+    # Motor velocity constant
+    self.Kv = ((self.free_speed / 60.0 * 2.0 * numpy.pi) /
+               (12.0 - self.R * self.free_current))
+    # Torque constant
+    self.Kt = self.stall_torque / self.stall_current
+    # Gear ratio
+    self.G = (44.0 / 12.0) * (54.0 / 14.0) * (54.0 / 14.0) * (44.0 / 20.0) * (72.0 / 16.0)
+    # Fridge arm length
+    self.r = 32 * 0.0254
+    # Control loop time step
+    self.dt = 0.005
+
+    # Arm moment of inertia
+    self.J = self.r * self.mass
+
+    # Arm left/right spring constant (N*m / radian)
+    self.spring = 100.0
+
+    # State is [average position, average velocity,
+    #           position difference/2, velocity difference/2]
+    # Position difference is 1 - 2
+    # Input is [Voltage 1, Voltage 2]
+
+    self.C1 = self.spring / (self.J * 0.5)
+    self.C2 = self.Kt * self.G / (self.J * 0.5 * self.R)
+    self.C3 = self.G * self.G * self.Kt / (self.R  * self.J * 0.5 * self.Kv)
+
+    self.A_continuous = numpy.matrix(
+        [[0, 1, 0, 0],
+         [0, -self.C3, 0, 0],
+         [0, 0, 0, 1],
+         [0, 0, -self.C1 * 2.0, -self.C3]])
+
+    print 'Full speed is', self.C2 / self.C3 * 12.0
+
+    print 'Stall arm difference is', 12.0 * self.C2 / self.C1
+    print 'Stall arm difference first principles is', self.stall_torque * self.G / self.spring
+
+    print '5 degrees of arm error is', self.spring / self.r * (math.pi * 5.0 / 180.0)
+
+    # Start with the unmodified input
+    self.B_continuous = numpy.matrix(
+        [[0, 0],
+         [self.C2 / 2.0, self.C2 / 2.0],
+         [0, 0],
+         [self.C2 / 2.0, -self.C2 / 2.0]])
+
+    self.C = numpy.matrix([[1, 0, 1, 0],
+                           [1, 0, -1, 0]])
+    self.D = numpy.matrix([[0, 0],
+                           [0, 0]])
+
+    self.A, self.B = self.ContinuousToDiscrete(
+        self.A_continuous, self.B_continuous, self.dt)
+
+    controlability = controls.ctrb(self.A, self.B);
+    print 'Rank of augmented controlability matrix.', numpy.linalg.matrix_rank(
+        controlability)
+
+    q_pos = 0.02
+    q_vel = 0.300
+    q_pos_diff = 0.005
+    q_vel_diff = 0.13
+    self.Q = numpy.matrix([[(1.0 / (q_pos ** 2.0)), 0.0, 0.0, 0.0],
+                           [0.0, (1.0 / (q_vel ** 2.0)), 0.0, 0.0],
+                           [0.0, 0.0, (1.0 / (q_pos_diff ** 2.0)), 0.0],
+                           [0.0, 0.0, 0.0, (1.0 / (q_vel_diff ** 2.0))]])
+
+    self.R = numpy.matrix([[(1.0 / (12.0 ** 2.0)), 0.0],
+                           [0.0, 1.0 / (12.0 ** 2.0)]])
+    self.K = controls.dlqr(self.A, self.B, self.Q, self.R)
+    print 'Controller'
+    print self.K
+
+    print 'Controller Poles'
+    print numpy.linalg.eig(self.A - self.B * self.K)[0]
+
+    self.rpl = 0.20
+    self.ipl = 0.05
+    self.PlaceObserverPoles([self.rpl + 1j * self.ipl,
+                             self.rpl + 1j * self.ipl,
+                             self.rpl - 1j * self.ipl,
+                             self.rpl - 1j * self.ipl])
+
+    # The box formed by U_min and U_max must encompass all possible values,
+    # or else Austin's code gets angry.
+    self.U_max = numpy.matrix([[12.0], [12.0]])
+    self.U_min = numpy.matrix([[-12.0], [-12.0]])
+
+    print 'Observer (Converted to a KF)', numpy.linalg.inv(self.A) * self.L
+
+    self.InitializeState()
+
+
+class IntegralArm(Arm):
+  def __init__(self, name="IntegralArm", mass=None):
+    super(IntegralArm, self).__init__(name=name, mass=mass)
+
+    self.A_continuous_unaugmented = self.A_continuous
+    self.A_continuous = numpy.matrix(numpy.zeros((5, 5)))
+    self.A_continuous[0:4, 0:4] = self.A_continuous_unaugmented
+    self.A_continuous[1, 4] = self.C2
+
+    # Start with the unmodified input
+    self.B_continuous_unaugmented = self.B_continuous
+    self.B_continuous = numpy.matrix(numpy.zeros((5, 2)))
+    self.B_continuous[0:4, 0:2] = self.B_continuous_unaugmented
+
+    self.C_unaugmented = self.C
+    self.C = numpy.matrix(numpy.zeros((2, 5)))
+    self.C[0:2, 0:4] = self.C_unaugmented
+
+    self.A, self.B = self.ContinuousToDiscrete(
+        self.A_continuous, self.B_continuous, self.dt)
+    print 'A cont', self.A_continuous
+    print 'B cont', self.B_continuous
+    print 'A discrete', self.A
+
+    q_pos = 0.08
+    q_vel = 0.40
+
+    q_pos_diff = 0.08
+    q_vel_diff = 0.40
+    q_voltage = 6.0
+    self.Q = numpy.matrix([[(q_pos ** 2.0), 0.0, 0.0, 0.0, 0.0],
+                           [0.0, (q_vel ** 2.0), 0.0, 0.0, 0.0],
+                           [0.0, 0.0, (q_pos_diff ** 2.0), 0.0, 0.0],
+                           [0.0, 0.0, 0.0, (q_vel_diff ** 2.0), 0.0],
+                           [0.0, 0.0, 0.0, 0.0, (q_voltage ** 2.0)]])
+
+    r_volts = 0.05
+    self.R = numpy.matrix([[(r_volts ** 2.0), 0.0],
+                           [0.0, (r_volts ** 2.0)]])
+
+    self.KalmanGain, self.Q_steady = controls.kalman(
+        A=self.A, B=self.B, C=self.C, Q=self.Q, R=self.R)
+
+    self.U_max = numpy.matrix([[12.0], [12.0]])
+    self.U_min = numpy.matrix([[-12.0], [-12.0]])
+
+    self.K_unaugmented = self.K
+    self.K = numpy.matrix(numpy.zeros((2, 5)));
+    self.K[0:2, 0:4] = self.K_unaugmented
+    self.K[0, 4] = 1;
+    self.K[1, 4] = 1;
+    print 'Kal', self.KalmanGain
+    self.L = self.A * self.KalmanGain
+
+    self.InitializeState()
+
+
+def CapU(U):
+  if U[0, 0] - U[1, 0] > 24:
+    return numpy.matrix([[12], [-12]])
+  elif U[0, 0] - U[1, 0] < -24:
+    return numpy.matrix([[-12], [12]])
+  else:
+    max_u = max(U[0, 0], U[1, 0])
+    min_u = min(U[0, 0], U[1, 0])
+    if max_u > 12:
+      return U - (max_u - 12)
+    if min_u < -12:
+      return U - (min_u + 12)
+    return U
+
+
+def run_test(arm, initial_X, goal, max_separation_error=0.01,
+             show_graph=True, iterations=200, controller_arm=None,
+             observer_arm=None):
+  """Runs the arm plant with an initial condition and goal.
+
+    The tests themselves are not terribly sophisticated; I just test for
+    whether the goal has been reached and whether the separation goes
+    outside of the initial and goal values by more than max_separation_error.
+    Prints out something for a failure of either condition and returns
+    False if tests fail.
+    Args:
+      arm: arm object to use.
+      initial_X: starting state.
+      goal: goal state.
+      show_graph: Whether or not to display a graph showing the changing
+           states and voltages.
+      iterations: Number of timesteps to run the model for.
+      controller_arm: arm object to get K from, or None if we should
+          use arm.
+      observer_arm: arm object to use for the observer, or None if we should
+          use the actual state.
+  """
+
+  arm.X = initial_X
+
+  if controller_arm is None:
+    controller_arm = arm
+
+  if observer_arm is not None:
+    observer_arm.X_hat = initial_X + 0.01
+    observer_arm.X_hat = initial_X
+
+  # Various lists for graphing things.
+  t = []
+  x_avg = []
+  x_sep = []
+  x_hat_avg = []
+  x_hat_sep = []
+  v_avg = []
+  v_sep = []
+  u_left = []
+  u_right = []
+
+  sep_plot_gain = 100.0
+
+  for i in xrange(iterations):
+    X_hat = arm.X
+    if observer_arm is not None:
+      X_hat = observer_arm.X_hat
+      x_hat_avg.append(observer_arm.X_hat[0, 0])
+      x_hat_sep.append(observer_arm.X_hat[2, 0] * sep_plot_gain)
+    U = controller_arm.K * (goal - X_hat)
+    U = CapU(U)
+    x_avg.append(arm.X[0, 0])
+    v_avg.append(arm.X[1, 0])
+    x_sep.append(arm.X[2, 0] * sep_plot_gain)
+    v_sep.append(arm.X[3, 0])
+    if observer_arm is not None:
+      observer_arm.PredictObserver(U)
+    arm.Update(U)
+    if observer_arm is not None:
+      observer_arm.Y = arm.Y
+      observer_arm.CorrectObserver(U)
+
+    t.append(i * arm.dt)
+    u_left.append(U[0, 0])
+    u_right.append(U[1, 0])
+
+  print numpy.linalg.inv(arm.A)
+  print "delta time is ", arm.dt
+  print "Velocity at t=0 is ", x_avg[0], v_avg[0], x_sep[0], v_sep[0]
+  print "Velocity at t=1+dt is ", x_avg[1], v_avg[1], x_sep[1], v_sep[1]
+
+  if show_graph:
+    pylab.subplot(2, 1, 1)
+    pylab.plot(t, x_avg, label='x avg')
+    pylab.plot(t, x_sep, label='x sep')
+    if observer_arm is not None:
+      pylab.plot(t, x_hat_avg, label='x_hat avg')
+      pylab.plot(t, x_hat_sep, label='x_hat sep')
+    pylab.legend()
+
+    pylab.subplot(2, 1, 2)
+    pylab.plot(t, u_left, label='u left')
+    pylab.plot(t, u_right, label='u right')
+    pylab.legend()
+    pylab.show()
+
+
+def run_integral_test(arm, initial_X, goal, observer_arm, disturbance,
+                      max_separation_error=0.01, show_graph=True,
+                      iterations=400):
+  """Runs the integral control arm plant with an initial condition and goal.
+
+    The tests themselves are not terribly sophisticated; I just test for
+    whether the goal has been reached and whether the separation goes
+    outside of the initial and goal values by more than max_separation_error.
+    Prints out something for a failure of either condition and returns
+    False if tests fail.
+    Args:
+      arm: arm object to use.
+      initial_X: starting state.
+      goal: goal state.
+      observer_arm: arm object to use for the observer.
+      show_graph: Whether or not to display a graph showing the changing
+           states and voltages.
+      iterations: Number of timesteps to run the model for.
+      disturbance: Voltage missmatch between controller and model.
+  """
+
+  arm.X = initial_X
+
+  # Various lists for graphing things.
+  t = []
+  x_avg = []
+  x_sep = []
+  x_hat_avg = []
+  x_hat_sep = []
+  v_avg = []
+  v_sep = []
+  u_left = []
+  u_right = []
+  u_error = []
+
+  sep_plot_gain = 100.0
+
+  unaugmented_goal = goal
+  goal = numpy.matrix(numpy.zeros((5, 1)))
+  goal[0:4, 0] = unaugmented_goal
+
+  for i in xrange(iterations):
+    X_hat = observer_arm.X_hat[0:4]
+
+    x_hat_avg.append(observer_arm.X_hat[0, 0])
+    x_hat_sep.append(observer_arm.X_hat[2, 0] * sep_plot_gain)
+
+    U = observer_arm.K * (goal - observer_arm.X_hat)
+    u_error.append(observer_arm.X_hat[4,0])
+    U = CapU(U)
+    x_avg.append(arm.X[0, 0])
+    v_avg.append(arm.X[1, 0])
+    x_sep.append(arm.X[2, 0] * sep_plot_gain)
+    v_sep.append(arm.X[3, 0])
+
+    observer_arm.PredictObserver(U)
+
+    arm.Update(U + disturbance)
+    observer_arm.Y = arm.Y
+    observer_arm.CorrectObserver(U)
+
+    t.append(i * arm.dt)
+    u_left.append(U[0, 0])
+    u_right.append(U[1, 0])
+
+  print 'End is', observer_arm.X_hat[4, 0]
+
+  if show_graph:
+    pylab.subplot(2, 1, 1)
+    pylab.plot(t, x_avg, label='x avg')
+    pylab.plot(t, x_sep, label='x sep')
+    if observer_arm is not None:
+      pylab.plot(t, x_hat_avg, label='x_hat avg')
+      pylab.plot(t, x_hat_sep, label='x_hat sep')
+    pylab.legend()
+
+    pylab.subplot(2, 1, 2)
+    pylab.plot(t, u_left, label='u left')
+    pylab.plot(t, u_right, label='u right')
+    pylab.plot(t, u_error, label='u error')
+    pylab.legend()
+    pylab.show()
+
+
+def main(argv):
+  loaded_mass = 25
+  #loaded_mass = 0
+  arm = Arm(mass=13 + loaded_mass)
+  #arm_controller = Arm(mass=13 + 15)
+  #observer_arm = Arm(mass=13 + 15)
+  #observer_arm = None
+
+  integral_arm = IntegralArm(mass=13 + loaded_mass)
+  integral_arm.X_hat[0, 0] += 0.02
+  integral_arm.X_hat[2, 0] += 0.02
+  integral_arm.X_hat[4] = 0
+
+  # Test moving the arm with constant separation.
+  initial_X = numpy.matrix([[0.0], [0.0], [0.0], [0.0]])
+  R = numpy.matrix([[0.0], [0.0], [0.0], [0.0]])
+  run_integral_test(arm, initial_X, R, integral_arm, disturbance=2)
+
+  # Write the generated constants out to a file.
+  if len(argv) != 5:
+    print "Expected .h file name and .cc file name for the arm and augmented arm."
+  else:
+    arm = Arm("Arm", mass=13)
+    loop_writer = control_loop.ControlLoopWriter("Arm", [arm])
+    if argv[1][-3:] == '.cc':
+      loop_writer.Write(argv[2], argv[1])
+    else:
+      loop_writer.Write(argv[1], argv[2])
+
+    integral_arm = IntegralArm("IntegralArm", mass=13)
+    loop_writer = control_loop.ControlLoopWriter("IntegralArm", [integral_arm])
+    if argv[3][-3:] == '.cc':
+      loop_writer.Write(argv[4], argv[3])
+    else:
+      loop_writer.Write(argv[3], argv[4])
+
+if __name__ == '__main__':
+  sys.exit(main(sys.argv))
diff --git a/y2015/control_loops/python/claw.py b/y2015/control_loops/python/claw.py
new file mode 100755
index 0000000..4ca50e9
--- /dev/null
+++ b/y2015/control_loops/python/claw.py
@@ -0,0 +1,211 @@
+#!/usr/bin/python
+
+import control_loop
+import controls
+import polytope
+import polydrivetrain
+import numpy
+import sys
+import matplotlib
+from matplotlib import pylab
+
+class Claw(control_loop.ControlLoop):
+  def __init__(self, name="Claw", mass=None):
+    super(Claw, self).__init__(name)
+    # Stall Torque in N m
+    self.stall_torque = 0.476
+    # Stall Current in Amps
+    self.stall_current = 80.730
+    # Free Speed in RPM
+    self.free_speed = 13906.0
+    # Free Current in Amps
+    self.free_current = 5.820
+    # Mass of the claw
+    if mass is None:
+      self.mass = 5.0
+    else:
+      self.mass = mass
+
+    # Resistance of the motor
+    self.R = 12.0 / self.stall_current
+    # Motor velocity constant
+    self.Kv = ((self.free_speed / 60.0 * 2.0 * numpy.pi) /
+               (12.0 - self.R * self.free_current))
+    # Torque constant
+    self.Kt = self.stall_torque / self.stall_current
+    # Gear ratio
+    self.G = (56.0 / 12.0) * (54.0 / 14.0) * (64.0 / 14.0) * (72.0 / 18.0)
+    # Claw length
+    self.r = 18 * 0.0254
+
+    self.J = self.r * self.mass
+
+    # Control loop time step
+    self.dt = 0.005
+
+    # State is [position, velocity]
+    # Input is [Voltage]
+
+    C1 = self.G * self.G * self.Kt / (self.R  * self.J * self.Kv)
+    C2 = self.Kt * self.G / (self.J * self.R)
+
+    self.A_continuous = numpy.matrix(
+        [[0, 1],
+         [0, -C1]])
+
+    # Start with the unmodified input
+    self.B_continuous = numpy.matrix(
+        [[0],
+         [C2]])
+
+    self.C = numpy.matrix([[1, 0]])
+    self.D = numpy.matrix([[0]])
+
+    self.A, self.B = self.ContinuousToDiscrete(
+        self.A_continuous, self.B_continuous, self.dt)
+
+    controlability = controls.ctrb(self.A, self.B);
+
+    print "Free speed is", self.free_speed * numpy.pi * 2.0 / 60.0 / self.G
+
+    q_pos = 0.15
+    q_vel = 2.5
+    self.Q = numpy.matrix([[(1.0 / (q_pos ** 2.0)), 0.0],
+                           [0.0, (1.0 / (q_vel ** 2.0))]])
+
+    self.R = numpy.matrix([[(1.0 / (12.0 ** 2.0))]])
+    self.K = controls.dlqr(self.A, self.B, self.Q, self.R)
+
+    print 'K', self.K
+    print 'Poles are', numpy.linalg.eig(self.A - self.B * self.K)[0]
+
+    self.rpl = 0.30
+    self.ipl = 0.10
+    self.PlaceObserverPoles([self.rpl + 1j * self.ipl,
+                             self.rpl - 1j * self.ipl])
+
+    print 'L is', self.L
+
+    q_pos = 0.05
+    q_vel = 2.65
+    self.Q = numpy.matrix([[(q_pos ** 2.0), 0.0],
+                           [0.0, (q_vel ** 2.0)]])
+
+    r_volts = 0.025
+    self.R = numpy.matrix([[(r_volts ** 2.0)]])
+
+    self.KalmanGain, self.Q_steady = controls.kalman(
+        A=self.A, B=self.B, C=self.C, Q=self.Q, R=self.R)
+
+    print 'Kal', self.KalmanGain
+    self.L = self.A * self.KalmanGain
+    print 'KalL is', self.L
+
+    # The box formed by U_min and U_max must encompass all possible values,
+    # or else Austin's code gets angry.
+    self.U_max = numpy.matrix([[12.0]])
+    self.U_min = numpy.matrix([[-12.0]])
+
+    self.InitializeState()
+
+
+def run_test(claw, initial_X, goal, max_separation_error=0.01,
+             show_graph=True, iterations=200, controller_claw=None,
+             observer_claw=None):
+  """Runs the claw plant with an initial condition and goal.
+
+    The tests themselves are not terribly sophisticated; I just test for
+    whether the goal has been reached and whether the separation goes
+    outside of the initial and goal values by more than max_separation_error.
+    Prints out something for a failure of either condition and returns
+    False if tests fail.
+    Args:
+      claw: claw object to use.
+      initial_X: starting state.
+      goal: goal state.
+      show_graph: Whether or not to display a graph showing the changing
+           states and voltages.
+      iterations: Number of timesteps to run the model for.
+      controller_claw: claw object to get K from, or None if we should
+          use claw.
+      observer_claw: claw object to use for the observer, or None if we should
+          use the actual state.
+  """
+
+  claw.X = initial_X
+
+  if controller_claw is None:
+    controller_claw = claw
+
+  if observer_claw is not None:
+    observer_claw.X_hat = initial_X + 0.01
+    observer_claw.X_hat = initial_X
+
+  # Various lists for graphing things.
+  t = []
+  x = []
+  v = []
+  x_hat = []
+  u = []
+
+  sep_plot_gain = 100.0
+
+  for i in xrange(iterations):
+    X_hat = claw.X
+    if observer_claw is not None:
+      X_hat = observer_claw.X_hat
+      x_hat.append(observer_claw.X_hat[0, 0])
+    U = controller_claw.K * (goal - X_hat)
+    U[0, 0] = numpy.clip(U[0, 0], -12, 12)
+    x.append(claw.X[0, 0])
+    v.append(claw.X[1, 0])
+    if observer_claw is not None:
+      observer_claw.PredictObserver(U)
+    claw.Update(U)
+    if observer_claw is not None:
+      observer_claw.Y = claw.Y
+      observer_claw.CorrectObserver(U)
+
+    t.append(i * claw.dt)
+    u.append(U[0, 0])
+
+  if show_graph:
+    pylab.subplot(2, 1, 1)
+    pylab.plot(t, x, label='x')
+    if observer_claw is not None:
+      pylab.plot(t, x_hat, label='x_hat')
+    pylab.legend()
+
+    pylab.subplot(2, 1, 2)
+    pylab.plot(t, u, label='u')
+    pylab.legend()
+    pylab.show()
+
+
+def main(argv):
+  loaded_mass = 0
+  #loaded_mass = 0
+  claw = Claw(mass=4 + loaded_mass)
+  claw_controller = Claw(mass=5 + 0)
+  observer_claw = Claw(mass=5 + 0)
+  #observer_claw = None
+
+  # Test moving the claw with constant separation.
+  initial_X = numpy.matrix([[0.0], [0.0]])
+  R = numpy.matrix([[1.0], [0.0]])
+  run_test(claw, initial_X, R, controller_claw=claw_controller,
+           observer_claw=observer_claw)
+
+  # Write the generated constants out to a file.
+  if len(argv) != 3:
+    print "Expected .h file name and .cc file name for the claw."
+  else:
+    claw = Claw("Claw")
+    loop_writer = control_loop.ControlLoopWriter("Claw", [claw])
+    if argv[1][-3:] == '.cc':
+      loop_writer.Write(argv[2], argv[1])
+    else:
+      loop_writer.Write(argv[1], argv[2])
+
+if __name__ == '__main__':
+  sys.exit(main(sys.argv))
diff --git a/y2015/control_loops/python/drivetrain.py b/y2015/control_loops/python/drivetrain.py
new file mode 100755
index 0000000..8ed62d6
--- /dev/null
+++ b/y2015/control_loops/python/drivetrain.py
@@ -0,0 +1,242 @@
+#!/usr/bin/python
+
+import control_loop
+import controls
+import numpy
+import sys
+from matplotlib import pylab
+
+
+class CIM(control_loop.ControlLoop):
+  def __init__(self):
+    super(CIM, self).__init__("CIM")
+    # Stall Torque in N m
+    self.stall_torque = 2.42
+    # Stall Current in Amps
+    self.stall_current = 133
+    # Free Speed in RPM
+    self.free_speed = 4650.0
+    # Free Current in Amps
+    self.free_current = 2.7
+    # Moment of inertia of the CIM in kg m^2
+    self.J = 0.0001
+    # Resistance of the motor, divided by 2 to account for the 2 motors
+    self.R = 12.0 / self.stall_current
+    # Motor velocity constant
+    self.Kv = ((self.free_speed / 60.0 * 2.0 * numpy.pi) /
+              (12.0 - self.R * self.free_current))
+    # Torque constant
+    self.Kt = self.stall_torque / self.stall_current
+    # Control loop time step
+    self.dt = 0.005
+
+    # State feedback matrices
+    self.A_continuous = numpy.matrix(
+        [[-self.Kt / self.Kv / (self.J * self.R)]])
+    self.B_continuous = numpy.matrix(
+        [[self.Kt / (self.J * self.R)]])
+    self.C = numpy.matrix([[1]])
+    self.D = numpy.matrix([[0]])
+
+    self.A, self.B = self.ContinuousToDiscrete(self.A_continuous,
+                                               self.B_continuous, self.dt)
+
+    self.PlaceControllerPoles([0.01])
+    self.PlaceObserverPoles([0.01])
+
+    self.U_max = numpy.matrix([[12.0]])
+    self.U_min = numpy.matrix([[-12.0]])
+
+    self.InitializeState()
+
+
+class Drivetrain(control_loop.ControlLoop):
+  def __init__(self, name="Drivetrain", left_low=True, right_low=True):
+    super(Drivetrain, self).__init__(name)
+    # Stall Torque in N m
+    self.stall_torque = 2.42
+    # Stall Current in Amps
+    self.stall_current = 133.0
+    # Free Speed in RPM. Used number from last year.
+    self.free_speed = 4650.0
+    # Free Current in Amps
+    self.free_current = 2.7
+    # Moment of inertia of the drivetrain in kg m^2
+    # Just borrowed from last year.
+    self.J = 10
+    # Mass of the robot, in kg.
+    self.m = 68
+    # Radius of the robot, in meters (from last year).
+    self.rb = 0.9603 / 2.0
+    # Radius of the wheels, in meters.
+    self.r = .0515938
+    # Resistance of the motor, divided by the number of motors.
+    self.R = 12.0 / self.stall_current / 2
+    # Motor velocity constant
+    self.Kv = ((self.free_speed / 60.0 * 2.0 * numpy.pi) /
+               (12.0 - self.R * self.free_current))
+    # Torque constant
+    self.Kt = self.stall_torque / self.stall_current
+    # Gear ratios
+    self.G_const = 28.0 / 50.0 * 20.0 / 64.0
+
+    self.G_low = self.G_const
+    self.G_high = self.G_const
+
+    if left_low:
+      self.Gl = self.G_low
+    else:
+      self.Gl = self.G_high
+    if right_low:
+      self.Gr = self.G_low
+    else:
+      self.Gr = self.G_high
+
+    # Control loop time step
+    self.dt = 0.005
+
+    # These describe the way that a given side of a robot will be influenced
+    # by the other side. Units of 1 / kg.
+    self.msp = 1.0 / self.m + self.rb * self.rb / self.J
+    self.msn = 1.0 / self.m - self.rb * self.rb / self.J
+    # The calculations which we will need for A and B.
+    self.tcl = -self.Kt / self.Kv / (self.Gl * self.Gl * self.R * self.r * self.r)
+    self.tcr = -self.Kt / self.Kv / (self.Gr * self.Gr * self.R * self.r * self.r)
+    self.mpl = self.Kt / (self.Gl * self.R * self.r)
+    self.mpr = self.Kt / (self.Gr * self.R * self.r)
+
+    # State feedback matrices
+    # X will be of the format
+    # [[positionl], [velocityl], [positionr], velocityr]]
+    self.A_continuous = numpy.matrix(
+        [[0, 1, 0, 0],
+         [0, self.msp * self.tcl, 0, self.msn * self.tcr],
+         [0, 0, 0, 1],
+         [0, self.msn * self.tcl, 0, self.msp * self.tcr]])
+    self.B_continuous = numpy.matrix(
+        [[0, 0],
+         [self.msp * self.mpl, self.msn * self.mpr],
+         [0, 0],
+         [self.msn * self.mpl, self.msp * self.mpr]])
+    self.C = numpy.matrix([[1, 0, 0, 0],
+                           [0, 0, 1, 0]])
+    self.D = numpy.matrix([[0, 0],
+                           [0, 0]])
+
+    #print "THE NUMBER I WANT" + str(numpy.linalg.inv(self.A_continuous) * -self.B_continuous * numpy.matrix([[12.0], [12.0]]))
+    self.A, self.B = self.ContinuousToDiscrete(
+        self.A_continuous, self.B_continuous, self.dt)
+
+    # Poles from last year.
+    self.hp = 0.65
+    self.lp = 0.83
+    self.PlaceControllerPoles([self.hp, self.lp, self.hp, self.lp])
+    print self.K
+    q_pos = 0.07
+    q_vel = 1.0
+    self.Q = numpy.matrix([[(1.0 / (q_pos ** 2.0)), 0.0, 0.0, 0.0],
+                           [0.0, (1.0 / (q_vel ** 2.0)), 0.0, 0.0],
+                           [0.0, 0.0, (1.0 / (q_pos ** 2.0)), 0.0],
+                           [0.0, 0.0, 0.0, (1.0 / (q_vel ** 2.0))]])
+
+    self.R = numpy.matrix([[(1.0 / (12.0 ** 2.0)), 0.0],
+                           [0.0, (1.0 / (12.0 ** 2.0))]])
+    self.K = controls.dlqr(self.A, self.B, self.Q, self.R)
+    print self.A
+    print self.B
+    print self.K
+    print numpy.linalg.eig(self.A - self.B * self.K)[0]
+
+    self.hlp = 0.3
+    self.llp = 0.4
+    self.PlaceObserverPoles([self.hlp, self.hlp, self.llp, self.llp])
+
+    self.U_max = numpy.matrix([[12.0], [12.0]])
+    self.U_min = numpy.matrix([[-12.0], [-12.0]])
+    self.InitializeState()
+
+def main(argv):
+  # Simulate the response of the system to a step input.
+  drivetrain = Drivetrain()
+  simulated_left = []
+  simulated_right = []
+  for _ in xrange(100):
+    drivetrain.Update(numpy.matrix([[12.0], [12.0]]))
+    simulated_left.append(drivetrain.X[0, 0])
+    simulated_right.append(drivetrain.X[2, 0])
+
+  #pylab.plot(range(100), simulated_left)
+  #pylab.plot(range(100), simulated_right)
+  #pylab.show()
+
+  # Simulate forwards motion.
+  drivetrain = Drivetrain()
+  close_loop_left = []
+  close_loop_right = []
+  R = numpy.matrix([[1.0], [0.0], [1.0], [0.0]])
+  for _ in xrange(100):
+    U = numpy.clip(drivetrain.K * (R - drivetrain.X_hat),
+                   drivetrain.U_min, drivetrain.U_max)
+    drivetrain.UpdateObserver(U)
+    drivetrain.Update(U)
+    close_loop_left.append(drivetrain.X[0, 0])
+    close_loop_right.append(drivetrain.X[2, 0])
+
+  #pylab.plot(range(100), close_loop_left)
+  #pylab.plot(range(100), close_loop_right)
+  #pylab.show()
+
+  # Try turning in place
+  drivetrain = Drivetrain()
+  close_loop_left = []
+  close_loop_right = []
+  R = numpy.matrix([[-1.0], [0.0], [1.0], [0.0]])
+  for _ in xrange(100):
+    U = numpy.clip(drivetrain.K * (R - drivetrain.X_hat),
+                   drivetrain.U_min, drivetrain.U_max)
+    drivetrain.UpdateObserver(U)
+    drivetrain.Update(U)
+    close_loop_left.append(drivetrain.X[0, 0])
+    close_loop_right.append(drivetrain.X[2, 0])
+
+  #pylab.plot(range(100), close_loop_left)
+  #pylab.plot(range(100), close_loop_right)
+  #pylab.show()
+
+  # Try turning just one side.
+  drivetrain = Drivetrain()
+  close_loop_left = []
+  close_loop_right = []
+  R = numpy.matrix([[0.0], [0.0], [1.0], [0.0]])
+  for _ in xrange(100):
+    U = numpy.clip(drivetrain.K * (R - drivetrain.X_hat),
+                   drivetrain.U_min, drivetrain.U_max)
+    drivetrain.UpdateObserver(U)
+    drivetrain.Update(U)
+    close_loop_left.append(drivetrain.X[0, 0])
+    close_loop_right.append(drivetrain.X[2, 0])
+
+  #pylab.plot(range(100), close_loop_left)
+  #pylab.plot(range(100), close_loop_right)
+  #pylab.show()
+
+  # Write the generated constants out to a file.
+  print "Output one"
+  drivetrain_low_low = Drivetrain(name="DrivetrainLowLow", left_low=True, right_low=True)
+  drivetrain_low_high = Drivetrain(name="DrivetrainLowHigh", left_low=True, right_low=False)
+  drivetrain_high_low = Drivetrain(name="DrivetrainHighLow", left_low=False, right_low=True)
+  drivetrain_high_high = Drivetrain(name="DrivetrainHighHigh", left_low=False, right_low=False)
+
+  if len(argv) != 5:
+    print "Expected .h file name and .cc file name"
+  else:
+    dog_loop_writer = control_loop.ControlLoopWriter(
+        "Drivetrain", [drivetrain_low_low, drivetrain_low_high,
+                       drivetrain_high_low, drivetrain_high_high])
+    if argv[1][-3:] == '.cc':
+      dog_loop_writer.Write(argv[2], argv[1])
+    else:
+      dog_loop_writer.Write(argv[1], argv[2])
+
+if __name__ == '__main__':
+  sys.exit(main(sys.argv))
diff --git a/y2015/control_loops/python/elevator.py b/y2015/control_loops/python/elevator.py
new file mode 100755
index 0000000..fba72c8
--- /dev/null
+++ b/y2015/control_loops/python/elevator.py
@@ -0,0 +1,246 @@
+#!/usr/bin/python
+
+import control_loop
+import controls
+import polytope
+import polydrivetrain
+import numpy
+import sys
+import matplotlib
+from matplotlib import pylab
+
+class Elevator(control_loop.ControlLoop):
+  def __init__(self, name="Elevator", mass=None):
+    super(Elevator, self).__init__(name)
+    # Stall Torque in N m
+    self.stall_torque = 0.476
+    # Stall Current in Amps
+    self.stall_current = 80.730
+    # Free Speed in RPM
+    self.free_speed = 13906.0
+    # Free Current in Amps
+    self.free_current = 5.820
+    # Mass of the elevator
+    if mass is None:
+      self.mass = 13.0
+    else:
+      self.mass = mass
+
+    # Resistance of the motor
+    self.R = 12.0 / self.stall_current
+    # Motor velocity constant
+    self.Kv = ((self.free_speed / 60.0 * 2.0 * numpy.pi) /
+               (12.0 - self.R * self.free_current))
+    # Torque constant
+    self.Kt = self.stall_torque / self.stall_current
+    # Gear ratio
+    self.G = (56.0 / 12.0) * (84.0 / 14.0)
+    # Pulley diameter
+    self.r = 32 * 0.005 / numpy.pi / 2.0
+    # Control loop time step
+    self.dt = 0.005
+
+    # Elevator left/right spring constant (N/m)
+    self.spring = 800.0
+
+    # State is [average position, average velocity,
+    #           position difference/2, velocity difference/2]
+    # Input is [V_left, V_right]
+
+    C1 = self.spring / (self.mass * 0.5)
+    C2 = self.Kt * self.G / (self.mass * 0.5 * self.r * self.R)
+    C3 = self.G * self.G * self.Kt / (
+        self.R  * self.r * self.r * self.mass * 0.5 * self.Kv)
+
+    self.A_continuous = numpy.matrix(
+        [[0, 1, 0, 0],
+         [0, -C3, 0, 0],
+         [0, 0, 0, 1],
+         [0, 0, -C1 * 2.0, -C3]])
+
+    print "Full speed is", C2 / C3 * 12.0
+
+    # Start with the unmodified input
+    self.B_continuous = numpy.matrix(
+        [[0, 0],
+         [C2 / 2.0, C2 / 2.0],
+         [0, 0],
+         [C2 / 2.0, -C2 / 2.0]])
+
+    self.C = numpy.matrix([[1, 0, 1, 0],
+                           [1, 0, -1, 0]])
+    self.D = numpy.matrix([[0, 0],
+                           [0, 0]])
+
+    self.A, self.B = self.ContinuousToDiscrete(
+        self.A_continuous, self.B_continuous, self.dt)
+
+    print self.A
+
+    controlability = controls.ctrb(self.A, self.B);
+    print "Rank of augmented controlability matrix.", numpy.linalg.matrix_rank(
+        controlability)
+
+    q_pos = 0.02
+    q_vel = 0.400
+    q_pos_diff = 0.01
+    q_vel_diff = 0.45
+    self.Q = numpy.matrix([[(1.0 / (q_pos ** 2.0)), 0.0, 0.0, 0.0],
+                           [0.0, (1.0 / (q_vel ** 2.0)), 0.0, 0.0],
+                           [0.0, 0.0, (1.0 / (q_pos_diff ** 2.0)), 0.0],
+                           [0.0, 0.0, 0.0, (1.0 / (q_vel_diff ** 2.0))]])
+
+    self.R = numpy.matrix([[(1.0 / (12.0 ** 2.0)), 0.0],
+                           [0.0, 1.0 / (12.0 ** 2.0)]])
+    self.K = controls.dlqr(self.A, self.B, self.Q, self.R)
+    print self.K
+
+    print numpy.linalg.eig(self.A - self.B * self.K)[0]
+
+    self.rpl = 0.20
+    self.ipl = 0.05
+    self.PlaceObserverPoles([self.rpl + 1j * self.ipl,
+                             self.rpl + 1j * self.ipl,
+                             self.rpl - 1j * self.ipl,
+                             self.rpl - 1j * self.ipl])
+
+    # The box formed by U_min and U_max must encompass all possible values,
+    # or else Austin's code gets angry.
+    self.U_max = numpy.matrix([[12.0], [12.0]])
+    self.U_min = numpy.matrix([[-12.0], [-12.0]])
+
+    self.InitializeState()
+
+
+def CapU(U):
+  if U[0, 0] - U[1, 0] > 24:
+    return numpy.matrix([[12], [-12]])
+  elif U[0, 0] - U[1, 0] < -24:
+    return numpy.matrix([[-12], [12]])
+  else:
+    max_u = max(U[0, 0], U[1, 0])
+    min_u = min(U[0, 0], U[1, 0])
+    if max_u > 12:
+      return U - (max_u - 12)
+    if min_u < -12:
+      return U - (min_u + 12)
+    return U
+
+
+def run_test(elevator, initial_X, goal, max_separation_error=0.01,
+             show_graph=True, iterations=200, controller_elevator=None,
+             observer_elevator=None):
+  """Runs the elevator plant with an initial condition and goal.
+
+    The tests themselves are not terribly sophisticated; I just test for
+    whether the goal has been reached and whether the separation goes
+    outside of the initial and goal values by more than max_separation_error.
+    Prints out something for a failure of either condition and returns
+    False if tests fail.
+    Args:
+      elevator: elevator object to use.
+      initial_X: starting state.
+      goal: goal state.
+      show_graph: Whether or not to display a graph showing the changing
+           states and voltages.
+      iterations: Number of timesteps to run the model for.
+      controller_elevator: elevator object to get K from, or None if we should
+          use elevator.
+      observer_elevator: elevator object to use for the observer, or None if we
+          should use the actual state.
+  """
+
+  elevator.X = initial_X
+
+  if controller_elevator is None:
+    controller_elevator = elevator
+
+  if observer_elevator is not None:
+    observer_elevator.X_hat = initial_X + 0.01
+    observer_elevator.X_hat = initial_X
+
+  # Various lists for graphing things.
+  t = []
+  x_avg = []
+  x_sep = []
+  x_hat_avg = []
+  x_hat_sep = []
+  v_avg = []
+  v_sep = []
+  u_left = []
+  u_right = []
+
+  sep_plot_gain = 100.0
+
+  for i in xrange(iterations):
+    X_hat = elevator.X
+    if observer_elevator is not None:
+      X_hat = observer_elevator.X_hat
+      x_hat_avg.append(observer_elevator.X_hat[0, 0])
+      x_hat_sep.append(observer_elevator.X_hat[2, 0] * sep_plot_gain)
+    U = controller_elevator.K * (goal - X_hat)
+    U = CapU(U)
+    x_avg.append(elevator.X[0, 0])
+    v_avg.append(elevator.X[1, 0])
+    x_sep.append(elevator.X[2, 0] * sep_plot_gain)
+    v_sep.append(elevator.X[3, 0])
+    if observer_elevator is not None:
+      observer_elevator.PredictObserver(U)
+    elevator.Update(U)
+    if observer_elevator is not None:
+      observer_elevator.Y = elevator.Y
+      observer_elevator.CorrectObserver(U)
+
+    t.append(i * elevator.dt)
+    u_left.append(U[0, 0])
+    u_right.append(U[1, 0])
+
+  print numpy.linalg.inv(elevator.A)
+  print "delta time is ", elevator.dt
+  print "Velocity at t=0 is ", x_avg[0], v_avg[0], x_sep[0], v_sep[0]
+  print "Velocity at t=1+dt is ", x_avg[1], v_avg[1], x_sep[1], v_sep[1]
+
+  if show_graph:
+    pylab.subplot(2, 1, 1)
+    pylab.plot(t, x_avg, label='x avg')
+    pylab.plot(t, x_sep, label='x sep')
+    if observer_elevator is not None:
+      pylab.plot(t, x_hat_avg, label='x_hat avg')
+      pylab.plot(t, x_hat_sep, label='x_hat sep')
+    pylab.legend()
+
+    pylab.subplot(2, 1, 2)
+    pylab.plot(t, u_left, label='u left')
+    pylab.plot(t, u_right, label='u right')
+    pylab.legend()
+    pylab.show()
+
+
+def main(argv):
+  loaded_mass = 25
+  #loaded_mass = 0
+  elevator = Elevator(mass=13 + loaded_mass)
+  elevator_controller = Elevator(mass=13 + 15)
+  observer_elevator = Elevator(mass=13 + 15)
+  #observer_elevator = None
+
+  # Test moving the elevator with constant separation.
+  initial_X = numpy.matrix([[0.0], [0.0], [0.01], [0.0]])
+  #initial_X = numpy.matrix([[0.0], [0.0], [0.00], [0.0]])
+  R = numpy.matrix([[1.0], [0.0], [0.0], [0.0]])
+  run_test(elevator, initial_X, R, controller_elevator=elevator_controller,
+           observer_elevator=observer_elevator)
+
+  # Write the generated constants out to a file.
+  if len(argv) != 3:
+    print "Expected .h file name and .cc file name for the elevator."
+  else:
+    elevator = Elevator("Elevator")
+    loop_writer = control_loop.ControlLoopWriter("Elevator", [elevator])
+    if argv[1][-3:] == '.cc':
+      loop_writer.Write(argv[2], argv[1])
+    else:
+      loop_writer.Write(argv[1], argv[2])
+
+if __name__ == '__main__':
+  sys.exit(main(sys.argv))
diff --git a/y2015/control_loops/python/polydrivetrain.py b/y2015/control_loops/python/polydrivetrain.py
new file mode 100755
index 0000000..a62c8c8
--- /dev/null
+++ b/y2015/control_loops/python/polydrivetrain.py
@@ -0,0 +1,504 @@
+#!/usr/bin/python
+
+import numpy
+import sys
+import polytope
+import drivetrain
+import control_loop
+import controls
+from matplotlib import pylab
+
+__author__ = 'Austin Schuh (austin.linux@gmail.com)'
+
+
+def CoerceGoal(region, K, w, R):
+  """Intersects a line with a region, and finds the closest point to R.
+
+  Finds a point that is closest to R inside the region, and on the line
+  defined by K X = w.  If it is not possible to find a point on the line,
+  finds a point that is inside the region and closest to the line.  This
+  function assumes that
+
+  Args:
+    region: HPolytope, the valid goal region.
+    K: numpy.matrix (2 x 1), the matrix for the equation [K1, K2] [x1; x2] = w
+    w: float, the offset in the equation above.
+    R: numpy.matrix (2 x 1), the point to be closest to.
+
+  Returns:
+    numpy.matrix (2 x 1), the point.
+  """
+  return DoCoerceGoal(region, K, w, R)[0]
+
+def DoCoerceGoal(region, K, w, R):
+  if region.IsInside(R):
+    return (R, True)
+
+  perpendicular_vector = K.T / numpy.linalg.norm(K)
+  parallel_vector = numpy.matrix([[perpendicular_vector[1, 0]],
+                                  [-perpendicular_vector[0, 0]]])
+  
+  # We want to impose the constraint K * X = w on the polytope H * X <= k.
+  # We do this by breaking X up into parallel and perpendicular components to
+  # the half plane.  This gives us the following equation.
+  #
+  #  parallel * (parallel.T \dot X) + perpendicular * (perpendicular \dot X)) = X
+  #
+  # Then, substitute this into the polytope.
+  #
+  #  H * (parallel * (parallel.T \dot X) + perpendicular * (perpendicular \dot X)) <= k
+  #
+  # Substitute K * X = w
+  #
+  # H * parallel * (parallel.T \dot X) + H * perpendicular * w <= k
+  #
+  # Move all the knowns to the right side.
+  #
+  # H * parallel * ([parallel1 parallel2] * X) <= k - H * perpendicular * w
+  #
+  # Let t = parallel.T \dot X, the component parallel to the surface.
+  #
+  # H * parallel * t <= k - H * perpendicular * w
+  #
+  # This is a polytope which we can solve, and use to figure out the range of X
+  # that we care about!
+
+  t_poly = polytope.HPolytope(
+      region.H * parallel_vector,
+      region.k - region.H * perpendicular_vector * w)
+
+  vertices = t_poly.Vertices()
+
+  if vertices.shape[0]:
+    # The region exists!
+    # Find the closest vertex
+    min_distance = numpy.infty
+    closest_point = None
+    for vertex in vertices:
+      point = parallel_vector * vertex + perpendicular_vector * w
+      length = numpy.linalg.norm(R - point)
+      if length < min_distance:
+        min_distance = length
+        closest_point = point
+
+    return (closest_point, True)
+  else:
+    # Find the vertex of the space that is closest to the line.
+    region_vertices = region.Vertices()
+    min_distance = numpy.infty
+    closest_point = None
+    for vertex in region_vertices:
+      point = vertex.T
+      length = numpy.abs((perpendicular_vector.T * point)[0, 0])
+      if length < min_distance:
+        min_distance = length
+        closest_point = point
+
+    return (closest_point, False)
+
+
+class VelocityDrivetrainModel(control_loop.ControlLoop):
+  def __init__(self, left_low=True, right_low=True, name="VelocityDrivetrainModel"):
+    super(VelocityDrivetrainModel, self).__init__(name)
+    self._drivetrain = drivetrain.Drivetrain(left_low=left_low,
+                                             right_low=right_low)
+    self.dt = 0.01
+    self.A_continuous = numpy.matrix(
+        [[self._drivetrain.A_continuous[1, 1], self._drivetrain.A_continuous[1, 3]],
+         [self._drivetrain.A_continuous[3, 1], self._drivetrain.A_continuous[3, 3]]])
+
+    self.B_continuous = numpy.matrix(
+        [[self._drivetrain.B_continuous[1, 0], self._drivetrain.B_continuous[1, 1]],
+         [self._drivetrain.B_continuous[3, 0], self._drivetrain.B_continuous[3, 1]]])
+    self.C = numpy.matrix(numpy.eye(2));
+    self.D = numpy.matrix(numpy.zeros((2, 2)));
+
+    self.A, self.B = self.ContinuousToDiscrete(self.A_continuous,
+                                               self.B_continuous, self.dt)
+
+    # FF * X = U (steady state)
+    self.FF = self.B.I * (numpy.eye(2) - self.A)
+
+    self.PlaceControllerPoles([0.6, 0.6])
+    self.PlaceObserverPoles([0.02, 0.02])
+
+    self.G_high = self._drivetrain.G_high
+    self.G_low = self._drivetrain.G_low
+    self.R = self._drivetrain.R
+    self.r = self._drivetrain.r
+    self.Kv = self._drivetrain.Kv
+    self.Kt = self._drivetrain.Kt
+
+    self.U_max = self._drivetrain.U_max
+    self.U_min = self._drivetrain.U_min
+
+
+class VelocityDrivetrain(object):
+  HIGH = 'high'
+  LOW = 'low'
+  SHIFTING_UP = 'up'
+  SHIFTING_DOWN = 'down'
+
+  def __init__(self):
+    self.drivetrain_low_low = VelocityDrivetrainModel(
+        left_low=True, right_low=True, name='VelocityDrivetrainLowLow')
+    self.drivetrain_low_high = VelocityDrivetrainModel(left_low=True, right_low=False, name='VelocityDrivetrainLowHigh')
+    self.drivetrain_high_low = VelocityDrivetrainModel(left_low=False, right_low=True, name = 'VelocityDrivetrainHighLow')
+    self.drivetrain_high_high = VelocityDrivetrainModel(left_low=False, right_low=False, name = 'VelocityDrivetrainHighHigh')
+
+    # X is [lvel, rvel]
+    self.X = numpy.matrix(
+        [[0.0],
+         [0.0]])
+
+    self.U_poly = polytope.HPolytope(
+        numpy.matrix([[1, 0],
+                      [-1, 0],
+                      [0, 1],
+                      [0, -1]]),
+        numpy.matrix([[12],
+                      [12],
+                      [12],
+                      [12]]))
+
+    self.U_max = numpy.matrix(
+        [[12.0],
+         [12.0]])
+    self.U_min = numpy.matrix(
+        [[-12.0000000000],
+         [-12.0000000000]])
+
+    self.dt = 0.01
+
+    self.R = numpy.matrix(
+        [[0.0],
+         [0.0]])
+
+    # ttrust is the comprimise between having full throttle negative inertia,
+    # and having no throttle negative inertia.  A value of 0 is full throttle
+    # inertia.  A value of 1 is no throttle negative inertia.
+    self.ttrust = 1.1
+
+    self.left_gear = VelocityDrivetrain.LOW
+    self.right_gear = VelocityDrivetrain.LOW
+    self.left_shifter_position = 0.0
+    self.right_shifter_position = 0.0
+    self.left_cim = drivetrain.CIM()
+    self.right_cim = drivetrain.CIM()
+
+  def IsInGear(self, gear):
+    return gear is VelocityDrivetrain.HIGH or gear is VelocityDrivetrain.LOW
+
+  def MotorRPM(self, shifter_position, velocity):
+    if shifter_position > 0.5:
+      return (velocity / self.CurrentDrivetrain().G_high /
+              self.CurrentDrivetrain().r)
+    else:
+      return (velocity / self.CurrentDrivetrain().G_low /
+              self.CurrentDrivetrain().r)
+
+  def CurrentDrivetrain(self):
+    if self.left_shifter_position > 0.5:
+      if self.right_shifter_position > 0.5:
+        return self.drivetrain_high_high
+      else:
+        return self.drivetrain_high_low
+    else:
+      if self.right_shifter_position > 0.5:
+        return self.drivetrain_low_high
+      else:
+        return self.drivetrain_low_low
+
+  def SimShifter(self, gear, shifter_position):
+    if gear is VelocityDrivetrain.HIGH or gear is VelocityDrivetrain.SHIFTING_UP:
+      shifter_position = min(shifter_position + 0.5, 1.0)
+    else:
+      shifter_position = max(shifter_position - 0.5, 0.0)
+
+    if shifter_position == 1.0:
+      gear = VelocityDrivetrain.HIGH
+    elif shifter_position == 0.0:
+      gear = VelocityDrivetrain.LOW
+
+    return gear, shifter_position
+
+  def ComputeGear(self, wheel_velocity, should_print=False, current_gear=False, gear_name=None):
+    high_omega = (wheel_velocity / self.CurrentDrivetrain().G_high /
+                  self.CurrentDrivetrain().r)
+    low_omega = (wheel_velocity / self.CurrentDrivetrain().G_low /
+                 self.CurrentDrivetrain().r)
+    #print gear_name, "Motor Energy Difference.", 0.5 * 0.000140032647 * (low_omega * low_omega - high_omega * high_omega), "joules"
+    high_torque = ((12.0 - high_omega / self.CurrentDrivetrain().Kv) *
+                   self.CurrentDrivetrain().Kt / self.CurrentDrivetrain().R)
+    low_torque = ((12.0 - low_omega / self.CurrentDrivetrain().Kv) *
+                  self.CurrentDrivetrain().Kt / self.CurrentDrivetrain().R)
+    high_power = high_torque * high_omega
+    low_power = low_torque * low_omega
+    #if should_print:
+    #  print gear_name, "High omega", high_omega, "Low omega", low_omega
+    #  print gear_name, "High torque", high_torque, "Low torque", low_torque
+    #  print gear_name, "High power", high_power, "Low power", low_power
+
+    # Shift algorithm improvements.
+    # TODO(aschuh):
+    # It takes time to shift.  Shifting down for 1 cycle doesn't make sense
+    # because you will end up slower than without shifting.  Figure out how
+    # to include that info.
+    # If the driver is still in high gear, but isn't asking for the extra power
+    # from low gear, don't shift until he asks for it.
+    goal_gear_is_high = high_power > low_power
+    #goal_gear_is_high = True
+
+    if not self.IsInGear(current_gear):
+      print gear_name, 'Not in gear.'
+      return current_gear
+    else:
+      is_high = current_gear is VelocityDrivetrain.HIGH
+      if is_high != goal_gear_is_high:
+        if goal_gear_is_high:
+          print gear_name, 'Shifting up.'
+          return VelocityDrivetrain.SHIFTING_UP
+        else:
+          print gear_name, 'Shifting down.'
+          return VelocityDrivetrain.SHIFTING_DOWN
+      else:
+        return current_gear
+
+  def FilterVelocity(self, throttle):
+    # Invert the plant to figure out how the velocity filter would have to work
+    # out in order to filter out the forwards negative inertia.
+    # This math assumes that the left and right power and velocity are equal.
+
+    # The throttle filter should filter such that the motor in the highest gear
+    # should be controlling the time constant.
+    # Do this by finding the index of FF that has the lowest value, and computing
+    # the sums using that index.
+    FF_sum = self.CurrentDrivetrain().FF.sum(axis=1)
+    min_FF_sum_index = numpy.argmin(FF_sum)
+    min_FF_sum = FF_sum[min_FF_sum_index, 0]
+    min_K_sum = self.CurrentDrivetrain().K[min_FF_sum_index, :].sum()
+    # Compute the FF sum for high gear.
+    high_min_FF_sum = self.drivetrain_high_high.FF[0, :].sum()
+
+    # U = self.K[0, :].sum() * (R - x_avg) + self.FF[0, :].sum() * R
+    # throttle * 12.0 = (self.K[0, :].sum() + self.FF[0, :].sum()) * R
+    #                   - self.K[0, :].sum() * x_avg
+
+    # R = (throttle * 12.0 + self.K[0, :].sum() * x_avg) /
+    #     (self.K[0, :].sum() + self.FF[0, :].sum())
+
+    # U = (K + FF) * R - K * X
+    # (K + FF) ^-1 * (U + K * X) = R
+
+    # Scale throttle by min_FF_sum / high_min_FF_sum.  This will make low gear
+    # have the same velocity goal as high gear, and so that the robot will hold
+    # the same speed for the same throttle for all gears.
+    adjusted_ff_voltage = numpy.clip(throttle * 12.0 * min_FF_sum / high_min_FF_sum, -12.0, 12.0)
+    return ((adjusted_ff_voltage + self.ttrust * min_K_sum * (self.X[0, 0] + self.X[1, 0]) / 2.0)
+            / (self.ttrust * min_K_sum + min_FF_sum))
+
+  def Update(self, throttle, steering):
+    # Shift into the gear which sends the most power to the floor.
+    # This is the same as sending the most torque down to the floor at the
+    # wheel.
+
+    self.left_gear = self.right_gear = True
+    if False:
+      self.left_gear = self.ComputeGear(self.X[0, 0], should_print=True,
+                                        current_gear=self.left_gear,
+                                        gear_name="left")
+      self.right_gear = self.ComputeGear(self.X[1, 0], should_print=True,
+                                         current_gear=self.right_gear,
+                                         gear_name="right")
+      if self.IsInGear(self.left_gear):
+        self.left_cim.X[0, 0] = self.MotorRPM(self.left_shifter_position, self.X[0, 0])
+
+      if self.IsInGear(self.right_gear):
+        self.right_cim.X[0, 0] = self.MotorRPM(self.right_shifter_position, self.X[0, 0])
+
+    steering *= 2.3
+    if True or self.IsInGear(self.left_gear) and self.IsInGear(self.right_gear):
+      # Filter the throttle to provide a nicer response.
+      fvel = self.FilterVelocity(throttle)
+
+      # Constant radius means that angualar_velocity / linear_velocity = constant.
+      # Compute the left and right velocities.
+      steering_velocity = numpy.abs(fvel) * steering
+      left_velocity = fvel - steering_velocity
+      right_velocity = fvel + steering_velocity
+
+      # Write this constraint in the form of K * R = w
+      # angular velocity / linear velocity = constant
+      # (left - right) / (left + right) = constant
+      # left - right = constant * left + constant * right
+
+      # (fvel - steering * numpy.abs(fvel) - fvel - steering * numpy.abs(fvel)) /
+      #  (fvel - steering * numpy.abs(fvel) + fvel + steering * numpy.abs(fvel)) =
+      #       constant
+      # (- 2 * steering * numpy.abs(fvel)) / (2 * fvel) = constant
+      # (-steering * sign(fvel)) = constant
+      # (-steering * sign(fvel)) * (left + right) = left - right
+      # (steering * sign(fvel) + 1) * left + (steering * sign(fvel) - 1) * right = 0
+
+      equality_k = numpy.matrix(
+          [[1 + steering * numpy.sign(fvel), -(1 - steering * numpy.sign(fvel))]])
+      equality_w = 0.0
+
+      self.R[0, 0] = left_velocity
+      self.R[1, 0] = right_velocity
+
+      # Construct a constraint on R by manipulating the constraint on U
+      # Start out with H * U <= k
+      # U = FF * R + K * (R - X)
+      # H * (FF * R + K * R - K * X) <= k
+      # H * (FF + K) * R <= k + H * K * X
+      R_poly = polytope.HPolytope(
+          self.U_poly.H * (self.CurrentDrivetrain().K + self.CurrentDrivetrain().FF),
+          self.U_poly.k + self.U_poly.H * self.CurrentDrivetrain().K * self.X)
+
+      # Limit R back inside the box.
+      self.boxed_R = CoerceGoal(R_poly, equality_k, equality_w, self.R)
+
+      FF_volts = self.CurrentDrivetrain().FF * self.boxed_R
+      self.U_ideal = self.CurrentDrivetrain().K * (self.boxed_R - self.X) + FF_volts
+    else:
+      print 'Not all in gear'
+      if not self.IsInGear(self.left_gear) and not self.IsInGear(self.right_gear):
+        # TODO(austin): Use battery volts here.
+        R_left = self.MotorRPM(self.left_shifter_position, self.X[0, 0])
+        self.U_ideal[0, 0] = numpy.clip(
+            self.left_cim.K * (R_left - self.left_cim.X) + R_left / self.left_cim.Kv,
+            self.left_cim.U_min, self.left_cim.U_max)
+        self.left_cim.Update(self.U_ideal[0, 0])
+
+        R_right = self.MotorRPM(self.right_shifter_position, self.X[1, 0])
+        self.U_ideal[1, 0] = numpy.clip(
+            self.right_cim.K * (R_right - self.right_cim.X) + R_right / self.right_cim.Kv,
+            self.right_cim.U_min, self.right_cim.U_max)
+        self.right_cim.Update(self.U_ideal[1, 0])
+      else:
+        assert False
+
+    self.U = numpy.clip(self.U_ideal, self.U_min, self.U_max)
+
+    # TODO(austin): Model the robot as not accelerating when you shift...
+    # This hack only works when you shift at the same time.
+    if True or self.IsInGear(self.left_gear) and self.IsInGear(self.right_gear):
+      self.X = self.CurrentDrivetrain().A * self.X + self.CurrentDrivetrain().B * self.U
+
+    self.left_gear, self.left_shifter_position = self.SimShifter(
+        self.left_gear, self.left_shifter_position)
+    self.right_gear, self.right_shifter_position = self.SimShifter(
+        self.right_gear, self.right_shifter_position)
+
+    print "U is", self.U[0, 0], self.U[1, 0]
+    print "Left shifter", self.left_gear, self.left_shifter_position, "Right shifter", self.right_gear, self.right_shifter_position
+
+
+def main(argv):
+  vdrivetrain = VelocityDrivetrain()
+
+  if len(argv) != 7:
+    print "Expected .h file name and .cc file name"
+  else:
+    dog_loop_writer = control_loop.ControlLoopWriter(
+        "VelocityDrivetrain", [vdrivetrain.drivetrain_low_low,
+                       vdrivetrain.drivetrain_low_high,
+                       vdrivetrain.drivetrain_high_low,
+                       vdrivetrain.drivetrain_high_high])
+
+    if argv[1][-3:] == '.cc':
+      dog_loop_writer.Write(argv[2], argv[1])
+    else:
+      dog_loop_writer.Write(argv[1], argv[2])
+
+    cim_writer = control_loop.ControlLoopWriter(
+        "CIM", [drivetrain.CIM()])
+
+    if argv[5][-3:] == '.cc':
+      cim_writer.Write(argv[6], argv[5])
+    else:
+      cim_writer.Write(argv[5], argv[6])
+    return
+
+  vl_plot = []
+  vr_plot = []
+  ul_plot = []
+  ur_plot = []
+  radius_plot = []
+  t_plot = []
+  left_gear_plot = []
+  right_gear_plot = []
+  vdrivetrain.left_shifter_position = 0.0
+  vdrivetrain.right_shifter_position = 0.0
+  vdrivetrain.left_gear = VelocityDrivetrain.LOW
+  vdrivetrain.right_gear = VelocityDrivetrain.LOW
+
+  print "K is", vdrivetrain.CurrentDrivetrain().K
+
+  if vdrivetrain.left_gear is VelocityDrivetrain.HIGH:
+    print "Left is high"
+  else:
+    print "Left is low"
+  if vdrivetrain.right_gear is VelocityDrivetrain.HIGH:
+    print "Right is high"
+  else:
+    print "Right is low"
+
+  for t in numpy.arange(0, 1.7, vdrivetrain.dt):
+    if t < 0.5:
+      vdrivetrain.Update(throttle=0.00, steering=1.0)
+    elif t < 1.2:
+      vdrivetrain.Update(throttle=0.5, steering=1.0)
+    else:
+      vdrivetrain.Update(throttle=0.00, steering=1.0)
+    t_plot.append(t)
+    vl_plot.append(vdrivetrain.X[0, 0])
+    vr_plot.append(vdrivetrain.X[1, 0])
+    ul_plot.append(vdrivetrain.U[0, 0])
+    ur_plot.append(vdrivetrain.U[1, 0])
+    left_gear_plot.append((vdrivetrain.left_gear is VelocityDrivetrain.HIGH) * 2.0 - 10.0)
+    right_gear_plot.append((vdrivetrain.right_gear is VelocityDrivetrain.HIGH) * 2.0 - 10.0)
+
+    fwd_velocity = (vdrivetrain.X[1, 0] + vdrivetrain.X[0, 0]) / 2
+    turn_velocity = (vdrivetrain.X[1, 0] - vdrivetrain.X[0, 0])
+    if abs(fwd_velocity) < 0.0000001:
+      radius_plot.append(turn_velocity)
+    else:
+      radius_plot.append(turn_velocity / fwd_velocity)
+
+  cim_velocity_plot = []
+  cim_voltage_plot = []
+  cim_time = []
+  cim = drivetrain.CIM()
+  R = numpy.matrix([[300]])
+  for t in numpy.arange(0, 0.5, cim.dt):
+    U = numpy.clip(cim.K * (R - cim.X) + R / cim.Kv, cim.U_min, cim.U_max)
+    cim.Update(U)
+    cim_velocity_plot.append(cim.X[0, 0])
+    cim_voltage_plot.append(U[0, 0] * 10)
+    cim_time.append(t)
+  pylab.plot(cim_time, cim_velocity_plot, label='cim spinup')
+  pylab.plot(cim_time, cim_voltage_plot, label='cim voltage')
+  pylab.legend()
+  pylab.show()
+
+  # TODO(austin):
+  # Shifting compensation.
+
+  # Tighten the turn.
+  # Closed loop drive.
+
+  pylab.plot(t_plot, vl_plot, label='left velocity')
+  pylab.plot(t_plot, vr_plot, label='right velocity')
+  pylab.plot(t_plot, ul_plot, label='left voltage')
+  pylab.plot(t_plot, ur_plot, label='right voltage')
+  pylab.plot(t_plot, radius_plot, label='radius')
+  pylab.plot(t_plot, left_gear_plot, label='left gear high')
+  pylab.plot(t_plot, right_gear_plot, label='right gear high')
+  pylab.legend()
+  pylab.show()
+  return 0
+
+if __name__ == '__main__':
+  sys.exit(main(sys.argv))
diff --git a/y2015/control_loops/python/polydrivetrain_test.py b/y2015/control_loops/python/polydrivetrain_test.py
new file mode 100755
index 0000000..434cdca
--- /dev/null
+++ b/y2015/control_loops/python/polydrivetrain_test.py
@@ -0,0 +1,82 @@
+#!/usr/bin/python
+
+import polydrivetrain
+import numpy
+from numpy.testing import *
+import polytope
+import unittest
+
+__author__ = 'Austin Schuh (austin.linux@gmail.com)'
+
+
+class TestVelocityDrivetrain(unittest.TestCase):
+  def MakeBox(self, x1_min, x1_max, x2_min, x2_max):
+    H = numpy.matrix([[1, 0],
+                      [-1, 0],
+                      [0, 1],
+                      [0, -1]])
+    K = numpy.matrix([[x1_max],
+                      [-x1_min],
+                      [x2_max],
+                      [-x2_min]])
+    return polytope.HPolytope(H, K)
+
+  def test_coerce_inside(self):
+    """Tests coercion when the point is inside the box."""
+    box = self.MakeBox(1, 2, 1, 2)
+
+    # x1 = x2
+    K = numpy.matrix([[1, -1]])
+    w = 0
+
+    assert_array_equal(polydrivetrain.CoerceGoal(box, K, w,
+                                                 numpy.matrix([[1.5], [1.5]])),
+                       numpy.matrix([[1.5], [1.5]]))
+
+  def test_coerce_outside_intersect(self):
+    """Tests coercion when the line intersects the box."""
+    box = self.MakeBox(1, 2, 1, 2)
+
+    # x1 = x2
+    K = numpy.matrix([[1, -1]])
+    w = 0
+
+    assert_array_equal(polydrivetrain.CoerceGoal(box, K, w, numpy.matrix([[5], [5]])),
+                       numpy.matrix([[2.0], [2.0]]))
+
+  def test_coerce_outside_no_intersect(self):
+    """Tests coercion when the line does not intersect the box."""
+    box = self.MakeBox(3, 4, 1, 2)
+
+    # x1 = x2
+    K = numpy.matrix([[1, -1]])
+    w = 0
+
+    assert_array_equal(polydrivetrain.CoerceGoal(box, K, w, numpy.matrix([[5], [5]])),
+                       numpy.matrix([[3.0], [2.0]]))
+
+  def test_coerce_middle_of_edge(self):
+    """Tests coercion when the line intersects the middle of an edge."""
+    box = self.MakeBox(0, 4, 1, 2)
+
+    # x1 = x2
+    K = numpy.matrix([[-1, 1]])
+    w = 0
+
+    assert_array_equal(polydrivetrain.CoerceGoal(box, K, w, numpy.matrix([[5], [5]])),
+                       numpy.matrix([[2.0], [2.0]]))
+
+  def test_coerce_perpendicular_line(self):
+    """Tests coercion when the line does not intersect and is in quadrant 2."""
+    box = self.MakeBox(1, 2, 1, 2)
+
+    # x1 = -x2
+    K = numpy.matrix([[1, 1]])
+    w = 0
+
+    assert_array_equal(polydrivetrain.CoerceGoal(box, K, w, numpy.matrix([[5], [5]])),
+                       numpy.matrix([[1.0], [1.0]]))
+
+
+if __name__ == '__main__':
+  unittest.main()
diff --git a/y2015/control_loops/python/shooter.py b/y2015/control_loops/python/shooter.py
new file mode 100755
index 0000000..69f2599
--- /dev/null
+++ b/y2015/control_loops/python/shooter.py
@@ -0,0 +1,254 @@
+#!/usr/bin/python
+
+import control_loop
+import numpy
+import sys
+from matplotlib import pylab
+
+class SprungShooter(control_loop.ControlLoop):
+  def __init__(self, name="RawSprungShooter"):
+    super(SprungShooter, self).__init__(name)
+    # Stall Torque in N m
+    self.stall_torque = .4982
+    # Stall Current in Amps
+    self.stall_current = 85
+    # Free Speed in RPM
+    self.free_speed = 19300.0
+    # Free Current in Amps
+    self.free_current = 1.2
+    # Effective mass of the shooter in kg.
+    # This rough estimate should about include the effect of the masses
+    # of the gears. If this number is too low, the eigen values of self.A
+    # will start to become extremely small.
+    self.J = 200
+    # Resistance of the motor, divided by the number of motors.
+    self.R = 12.0 / self.stall_current / 2.0
+    # Motor velocity constant
+    self.Kv = ((self.free_speed / 60.0 * 2.0 * numpy.pi) /
+               (12.0 - self.R * self.free_current))
+    # Torque constant
+    self.Kt = self.stall_torque / self.stall_current
+    # Spring constant for the springs, N/m
+    self.Ks = 2800.0
+    # Maximum extension distance (Distance from the 0 force point on the
+    # spring to the latch position.)
+    self.max_extension = 0.32385
+    # Gear ratio multiplied by radius of final sprocket.
+    self.G = 10.0 / 40.0 * 20.0 / 54.0 * 24.0 / 54.0 * 20.0 / 84.0 * 16.0 * (3.0 / 8.0) / (2.0 * numpy.pi) * 0.0254
+
+    # Control loop time step
+    self.dt = 0.01
+
+    # State feedback matrices
+    self.A_continuous = numpy.matrix(
+        [[0, 1],
+         [-self.Ks / self.J,
+          -self.Kt / self.Kv / (self.J * self.G * self.G * self.R)]])
+    self.B_continuous = numpy.matrix(
+        [[0],
+         [self.Kt / (self.J * self.G * self.R)]])
+    self.C = numpy.matrix([[1, 0]])
+    self.D = numpy.matrix([[0]])
+
+    self.A, self.B = self.ContinuousToDiscrete(
+        self.A_continuous, self.B_continuous, self.dt)
+
+    self.PlaceControllerPoles([0.45, 0.45])
+
+    self.rpl = .05
+    self.ipl = 0.008
+    self.PlaceObserverPoles([self.rpl,
+                             self.rpl])
+
+    self.U_max = numpy.matrix([[12.0]])
+    self.U_min = numpy.matrix([[-12.0]])
+
+    self.InitializeState()
+
+
+class Shooter(SprungShooter):
+  def __init__(self, name="RawShooter"):
+    super(Shooter, self).__init__(name)
+
+    # State feedback matrices
+    self.A_continuous = numpy.matrix(
+        [[0, 1],
+         [0, -self.Kt / self.Kv / (self.J * self.G * self.G * self.R)]])
+    self.B_continuous = numpy.matrix(
+        [[0],
+         [self.Kt / (self.J * self.G * self.R)]])
+
+    self.A, self.B = self.ContinuousToDiscrete(
+        self.A_continuous, self.B_continuous, self.dt)
+
+    self.PlaceControllerPoles([0.45, 0.45])
+
+    self.rpl = .05
+    self.ipl = 0.008
+    self.PlaceObserverPoles([self.rpl,
+                             self.rpl])
+
+    self.U_max = numpy.matrix([[12.0]])
+    self.U_min = numpy.matrix([[-12.0]])
+
+    self.InitializeState()
+
+
+class SprungShooterDeltaU(SprungShooter):
+  def __init__(self, name="SprungShooter"):
+    super(SprungShooterDeltaU, self).__init__(name)
+    A_unaugmented = self.A
+    B_unaugmented = self.B
+
+    self.A = numpy.matrix([[0.0, 0.0, 0.0],
+                           [0.0, 0.0, 0.0],
+                           [0.0, 0.0, 1.0]])
+    self.A[0:2, 0:2] = A_unaugmented
+    self.A[0:2, 2] = B_unaugmented
+
+    self.B = numpy.matrix([[0.0],
+                           [0.0],
+                           [1.0]])
+
+    self.C = numpy.matrix([[1.0, 0.0, 0.0]])
+    self.D = numpy.matrix([[0.0]])
+
+    self.PlaceControllerPoles([0.50, 0.35, 0.80])
+
+    print "K"
+    print self.K
+    print "Placed controller poles are"
+    print numpy.linalg.eig(self.A - self.B * self.K)[0]
+
+    self.rpl = .05
+    self.ipl = 0.008
+    self.PlaceObserverPoles([self.rpl + 1j * self.ipl,
+                             self.rpl - 1j * self.ipl, 0.90])
+    print "Placed observer poles are"
+    print numpy.linalg.eig(self.A - self.L * self.C)[0]
+
+    self.U_max = numpy.matrix([[12.0]])
+    self.U_min = numpy.matrix([[-12.0]])
+
+    self.InitializeState()
+
+
+class ShooterDeltaU(Shooter):
+  def __init__(self, name="Shooter"):
+    super(ShooterDeltaU, self).__init__(name)
+    A_unaugmented = self.A
+    B_unaugmented = self.B
+
+    self.A = numpy.matrix([[0.0, 0.0, 0.0],
+                           [0.0, 0.0, 0.0],
+                           [0.0, 0.0, 1.0]])
+    self.A[0:2, 0:2] = A_unaugmented
+    self.A[0:2, 2] = B_unaugmented
+
+    self.B = numpy.matrix([[0.0],
+                           [0.0],
+                           [1.0]])
+
+    self.C = numpy.matrix([[1.0, 0.0, 0.0]])
+    self.D = numpy.matrix([[0.0]])
+
+    self.PlaceControllerPoles([0.55, 0.45, 0.80])
+
+    print "K"
+    print self.K
+    print "Placed controller poles are"
+    print numpy.linalg.eig(self.A - self.B * self.K)[0]
+
+    self.rpl = .05
+    self.ipl = 0.008
+    self.PlaceObserverPoles([self.rpl + 1j * self.ipl,
+                             self.rpl - 1j * self.ipl, 0.90])
+    print "Placed observer poles are"
+    print numpy.linalg.eig(self.A - self.L * self.C)[0]
+
+    self.U_max = numpy.matrix([[12.0]])
+    self.U_min = numpy.matrix([[-12.0]])
+
+    self.InitializeState()
+
+
+def ClipDeltaU(shooter, old_voltage, delta_u):
+  old_u = old_voltage
+  new_u = numpy.clip(old_u + delta_u, shooter.U_min, shooter.U_max)
+  return new_u - old_u
+
+def main(argv):
+  # Simulate the response of the system to a goal.
+  sprung_shooter = SprungShooterDeltaU()
+  raw_sprung_shooter = SprungShooter()
+  close_loop_x = []
+  close_loop_u = []
+  goal_position = -0.3
+  R = numpy.matrix([[goal_position], [0.0], [-sprung_shooter.A[1, 0] / sprung_shooter.A[1, 2] * goal_position]])
+  voltage = numpy.matrix([[0.0]])
+  for _ in xrange(500):
+    U = sprung_shooter.K * (R - sprung_shooter.X_hat)
+    U = ClipDeltaU(sprung_shooter, voltage, U)
+    sprung_shooter.Y = raw_sprung_shooter.Y + 0.01
+    sprung_shooter.UpdateObserver(U)
+    voltage += U;
+    raw_sprung_shooter.Update(voltage)
+    close_loop_x.append(raw_sprung_shooter.X[0, 0] * 10)
+    close_loop_u.append(voltage[0, 0])
+
+  pylab.plot(range(500), close_loop_x)
+  pylab.plot(range(500), close_loop_u)
+  pylab.show()
+
+  shooter = ShooterDeltaU()
+  raw_shooter = Shooter()
+  close_loop_x = []
+  close_loop_u = []
+  goal_position = -0.3
+  R = numpy.matrix([[goal_position], [0.0], [-shooter.A[1, 0] / shooter.A[1, 2] * goal_position]])
+  voltage = numpy.matrix([[0.0]])
+  for _ in xrange(500):
+    U = shooter.K * (R - shooter.X_hat)
+    U = ClipDeltaU(shooter, voltage, U)
+    shooter.Y = raw_shooter.Y + 0.01
+    shooter.UpdateObserver(U)
+    voltage += U;
+    raw_shooter.Update(voltage)
+    close_loop_x.append(raw_shooter.X[0, 0] * 10)
+    close_loop_u.append(voltage[0, 0])
+
+  pylab.plot(range(500), close_loop_x)
+  pylab.plot(range(500), close_loop_u)
+  pylab.show()
+
+  # Write the generated constants out to a file.
+  if len(argv) != 5:
+    print "Expected .h file name and .cc file name for"
+    print "both the plant and unaugmented plant"
+  else:
+    unaug_sprung_shooter = SprungShooter("RawSprungShooter")
+    unaug_shooter = Shooter("RawShooter")
+    unaug_loop_writer = control_loop.ControlLoopWriter("RawShooter",
+                                                       [unaug_sprung_shooter,
+                                                        unaug_shooter])
+    if argv[3][-3:] == '.cc':
+      unaug_loop_writer.Write(argv[4], argv[3])
+    else:
+      unaug_loop_writer.Write(argv[3], argv[4])
+
+    sprung_shooter = SprungShooterDeltaU()
+    shooter = ShooterDeltaU()
+    loop_writer = control_loop.ControlLoopWriter("Shooter", [sprung_shooter,
+                                                             shooter])
+
+    loop_writer.AddConstant(control_loop.Constant("kMaxExtension", "%f",
+                                                  sprung_shooter.max_extension))
+    loop_writer.AddConstant(control_loop.Constant("kSpringConstant", "%f",
+                                                  sprung_shooter.Ks))
+    if argv[1][-3:] == '.cc':
+      loop_writer.Write(argv[2], argv[1])
+    else:
+      loop_writer.Write(argv[1], argv[2])
+
+if __name__ == '__main__':
+  sys.exit(main(sys.argv))
diff --git a/y2015/control_loops/update_arm.sh b/y2015/control_loops/update_arm.sh
new file mode 100755
index 0000000..2a10f93
--- /dev/null
+++ b/y2015/control_loops/update_arm.sh
@@ -0,0 +1,12 @@
+#!/bin/bash
+#
+# Updates the arm controllers (for both robots).
+
+cd $(dirname $0)
+
+export PYTHONPATH=../../frc971/control_loops/python
+
+./python/arm.py fridge/arm_motor_plant.cc \
+    fridge/arm_motor_plant.h \
+    fridge/integral_arm_plant.cc \
+    fridge/integral_arm_plant.h
diff --git a/y2015/control_loops/update_claw.sh b/y2015/control_loops/update_claw.sh
new file mode 100755
index 0000000..d37e737
--- /dev/null
+++ b/y2015/control_loops/update_claw.sh
@@ -0,0 +1,10 @@
+#!/bin/bash
+#
+# Updates the claw controllers (for both robots).
+
+cd $(dirname $0)
+
+export PYTHONPATH=../../frc971/control_loops/python
+
+./python/claw.py claw/claw_motor_plant.cc \
+    claw/claw_motor_plant.h
diff --git a/y2015/control_loops/update_drivetrain.sh b/y2015/control_loops/update_drivetrain.sh
new file mode 100755
index 0000000..ecd1c41
--- /dev/null
+++ b/y2015/control_loops/update_drivetrain.sh
@@ -0,0 +1,12 @@
+#!/bin/bash
+#
+# Updates the drivetrain controllers (for both robots).
+
+cd $(dirname $0)
+
+export PYTHONPATH=../../frc971/control_loops/python
+
+./python/drivetrain.py drivetrain/drivetrain_dog_motor_plant.h \
+    drivetrain/drivetrain_dog_motor_plant.cc \
+    drivetrain/drivetrain_clutch_motor_plant.h \
+    drivetrain/drivetrain_clutch_motor_plant.cc
diff --git a/y2015/control_loops/update_elevator.sh b/y2015/control_loops/update_elevator.sh
new file mode 100755
index 0000000..4a7edb4
--- /dev/null
+++ b/y2015/control_loops/update_elevator.sh
@@ -0,0 +1,10 @@
+#!/bin/bash
+#
+# Updates the elevator controllers (for both robots).
+
+cd $(dirname $0)
+
+export PYTHONPATH=../../frc971/control_loops/python
+
+./python/elevator.py fridge/elevator_motor_plant.cc \
+    fridge/elevator_motor_plant.h
diff --git a/y2015/control_loops/update_polydrivetrain.sh b/y2015/control_loops/update_polydrivetrain.sh
new file mode 100755
index 0000000..338e40e
--- /dev/null
+++ b/y2015/control_loops/update_polydrivetrain.sh
@@ -0,0 +1,14 @@
+#!/bin/bash
+#
+# Updates the polydrivetrain controllers (for both robots) and CIM models.
+
+cd $(dirname $0)
+
+export PYTHONPATH=../../frc971/control_loops/python
+
+./python/polydrivetrain.py drivetrain/polydrivetrain_dog_motor_plant.h \
+    drivetrain/polydrivetrain_dog_motor_plant.cc \
+    drivetrain/polydrivetrain_clutch_motor_plant.h \
+    drivetrain/polydrivetrain_clutch_motor_plant.cc \
+    drivetrain/polydrivetrain_cim_plant.h \
+    drivetrain/polydrivetrain_cim_plant.cc