Add code for prototyping with the 2012 drivebase

Change-Id: I16b5b2e9982f1911b410c25872eca7a00fa561f3
diff --git a/y2012/control_loops/drivetrain/polydrivetrain.cc b/y2012/control_loops/drivetrain/polydrivetrain.cc
new file mode 100644
index 0000000..598d635
--- /dev/null
+++ b/y2012/control_loops/drivetrain/polydrivetrain.cc
@@ -0,0 +1,332 @@
+#include "y2012/control_loops/drivetrain/polydrivetrain.h"
+
+#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 "aos/common/messages/robot_state.q.h"
+#include "frc971/control_loops/state_feedback_loop.h"
+#include "frc971/control_loops/coerce_goal.h"
+#include "y2012/control_loops/drivetrain/drivetrain.q.h"
+#include "y2012/control_loops/drivetrain/drivetrain_dog_motor_plant.h"
+#include "y2012/control_loops/drivetrain/polydrivetrain_dog_motor_plant.h"
+
+#define HAVE_SHIFTERS 1
+
+namespace y2012 {
+namespace control_loops {
+namespace drivetrain {
+
+using ::y2012::control_loops::GearLogging;
+using ::y2012::control_loops::CIMLogging;
+using ::frc971::control_loops::CoerceGoal;
+
+PolyDrivetrain::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>(
+          ::y2012::control_loops::drivetrain::MakeVelocityDrivetrainLoop())),
+      ttrust_(1.1),
+      wheel_(0.0),
+      throttle_(0.0),
+      quickturn_(false),
+      stale_count_(0),
+      position_time_delta_(kDt),
+      left_gear_(LOW),
+      right_gear_(LOW),
+      counter_(0) {
+  last_position_.Zero();
+  position_.Zero();
+}
+
+double PolyDrivetrain::MotorSpeed(bool high_gear, double velocity) {
+  if (high_gear) {
+    return velocity / kHighGearRatio / kWheelRadius;
+  } else {
+    return velocity / kLowGearRatio / kWheelRadius;
+  }
+}
+
+void PolyDrivetrain::SetGoal(double wheel, double throttle, bool quickturn,
+                             bool highgear) {
+  const double kWheelNonLinearity = 0.3;
+  // 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);
+  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 = highgear ? HIGH : LOW;
+
+  const Gear shift_up = HIGH;
+  const Gear shift_down = LOW;
+
+  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 PolyDrivetrain::SetPosition(
+    const ::y2012::control_loops::DrivetrainQueue::Position *position) {
+  if (position == NULL) {
+    ++stale_count_;
+  } else {
+    last_position_ = position_;
+    position_ = *position;
+    position_time_delta_ = (stale_count_ + 1) * kDt;
+    stale_count_ = 0;
+  }
+
+#if HAVE_SHIFTERS
+  if (position) {
+    if (left_gear_ == LOW) {
+      if (right_gear_ == LOW) {
+        loop_->set_controller_index(0);
+      } else {
+        loop_->set_controller_index(1);
+      }
+    } else {
+      if (right_gear_ == LOW) {
+        loop_->set_controller_index(2);
+      } else {
+        loop_->set_controller_index(3);
+      }
+    }
+  }
+#endif
+}
+
+double PolyDrivetrain::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 PolyDrivetrain::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 PolyDrivetrain::Update() {
+  // 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(left_gear_ == HIGH, current_left_velocity);
+  const double right_motor_speed =
+      MotorSpeed(right_gear_ == HIGH, 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);
+  }
+#endif
+
+#if HAVE_SHIFTERS
+  if (IsInGear(left_gear_) && IsInGear(right_gear_))
+#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;
+
+    // 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 PolyDrivetrain::SendMotors(
+    ::y2012::control_loops::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;
+  }
+}
+
+constexpr double PolyDrivetrain::kStallTorque;
+constexpr double PolyDrivetrain::kStallCurrent;
+constexpr double PolyDrivetrain::kFreeSpeed;
+constexpr double PolyDrivetrain::kFreeCurrent;
+constexpr double PolyDrivetrain::kWheelRadius;
+constexpr double PolyDrivetrain::kR;
+constexpr double PolyDrivetrain::Kv;
+constexpr double PolyDrivetrain::Kt;
+
+}  // namespace drivetrain
+}  // namespace control_loops
+}  // namespace y2012