Drive code works on Tantrum.

Need to write the spring code.  Drive now supports doubles...  What a
pain.

Change-Id: Id589acdc443dcd81242a21e3b0c26f81d6974dc8
diff --git a/frc971/control_loops/drivetrain/polydrivetrain.h b/frc971/control_loops/drivetrain/polydrivetrain.h
index c9b0714..d16e8a1 100644
--- a/frc971/control_loops/drivetrain/polydrivetrain.h
+++ b/frc971/control_loops/drivetrain/polydrivetrain.h
@@ -3,8 +3,18 @@
 
 #include "aos/common/controls/polytope.h"
 
+#include "aos/common/commonmath.h"
+#include "frc971/control_loops/coerce_goal.h"
 #include "frc971/control_loops/drivetrain/gear.h"
+#ifdef __linux__
 #include "frc971/control_loops/drivetrain/drivetrain.q.h"
+#include "aos/common/logging/logging.h"
+#include "aos/common/logging/matrix_logging.h"
+#include "aos/common/logging/queue_logging.h"
+#include "aos/common/messages/robot_state.q.h"
+#else
+#include "frc971/control_loops/drivetrain/drivetrain_uc.q.h"
+#endif  // __linux__
 #include "frc971/control_loops/state_feedback_loop.h"
 #include "frc971/control_loops/drivetrain/drivetrain_config.h"
 
@@ -12,17 +22,18 @@
 namespace control_loops {
 namespace drivetrain {
 
+template <typename Scalar = double>
 class PolyDrivetrain {
  public:
-  PolyDrivetrain(const DrivetrainConfig &dt_config,
-                 StateFeedbackLoop<7, 2, 4> *kf);
+  PolyDrivetrain(const DrivetrainConfig<Scalar> &dt_config,
+                 StateFeedbackLoop<7, 2, 4, Scalar> *kf);
 
   int controller_index() const { return loop_->index(); }
 
   // Computes the speed of the motor given the hall effect position and the
   // speed of the robot.
-  double MotorSpeed(const constants::ShifterHallEffect &hall_effect,
-                    double shifter_position, double velocity, Gear gear);
+  Scalar MotorSpeed(const constants::ShifterHallEffect &hall_effect,
+                    Scalar shifter_position, Scalar velocity, Gear gear);
 
   void SetGoal(const ::frc971::control_loops::DrivetrainQueue::Goal &goal);
 
@@ -30,9 +41,9 @@
       const ::frc971::control_loops::DrivetrainQueue::Position *position,
       Gear left_gear, Gear right_gear);
 
-  double FilterVelocity(double throttle) const;
+  Scalar FilterVelocity(Scalar throttle) const;
 
-  double MaxVelocity();
+  Scalar MaxVelocity();
 
   void Update();
 
@@ -44,16 +55,21 @@
   // requested state.
   Gear UpdateSingleGear(Gear requested_gear, Gear current_gear);
 
+  // Returns the current estimated velocity in m/s.
+  Scalar velocity() const {
+    return (loop_->mutable_X_hat()(0) + loop_->mutable_X_hat()(1)) / 2.0;
+  }
+
  private:
-  StateFeedbackLoop<7, 2, 4> *kf_;
+  StateFeedbackLoop<7, 2, 4, Scalar> *kf_;
 
-  const ::aos::controls::HVPolytope<2, 4, 4> U_Poly_;
+  const ::aos::controls::HVPolytope<2, 4, 4, Scalar> U_Poly_;
 
-  ::std::unique_ptr<StateFeedbackLoop<2, 2, 2>> loop_;
+  ::std::unique_ptr<StateFeedbackLoop<2, 2, 2, Scalar>> loop_;
 
-  const double ttrust_;
-  double wheel_;
-  double throttle_;
+  const Scalar ttrust_;
+  Scalar wheel_;
+  Scalar throttle_;
   bool quickturn_;
 
   Gear left_gear_;
@@ -62,18 +78,354 @@
   ::frc971::control_loops::DrivetrainQueue::Position last_position_;
   ::frc971::control_loops::DrivetrainQueue::Position position_;
   int counter_;
-  DrivetrainConfig dt_config_;
+  DrivetrainConfig<Scalar> dt_config_;
 
-  double goal_left_velocity_ = 0.0;
-  double goal_right_velocity_ = 0.0;
+  Scalar goal_left_velocity_ = 0.0;
+  Scalar goal_right_velocity_ = 0.0;
 
   // Stored from the last iteration, for logging shifting logic.
-  double left_motor_speed_ = 0.0;
-  double right_motor_speed_ = 0.0;
-  double current_left_velocity_ = 0.0;
-  double current_right_velocity_ = 0.0;
+  Scalar left_motor_speed_ = 0.0;
+  Scalar right_motor_speed_ = 0.0;
+  Scalar current_left_velocity_ = 0.0;
+  Scalar current_right_velocity_ = 0.0;
 };
 
+template <typename Scalar>
+PolyDrivetrain<Scalar>::PolyDrivetrain(
+    const DrivetrainConfig<Scalar> &dt_config,
+    StateFeedbackLoop<7, 2, 4, Scalar> *kf)
+    : kf_(kf),
+      U_Poly_((Eigen::Matrix<Scalar, 4, 2>() << /*[[*/ 1, 0 /*]*/,
+               /*[*/ -1, 0 /*]*/,
+               /*[*/ 0, 1 /*]*/,
+               /*[*/ 0, -1 /*]]*/)
+                  .finished(),
+              (Eigen::Matrix<Scalar, 4, 1>() << /*[[*/ 12 /*]*/,
+               /*[*/ 12 /*]*/,
+               /*[*/ 12 /*]*/,
+               /*[*/ 12 /*]]*/)
+                  .finished(),
+              (Eigen::Matrix<Scalar, 2, 4>() << /*[[*/ 12, 12, -12, -12 /*]*/,
+               /*[*/ -12, 12, 12, -12 /*]*/)
+                  .finished()),
+      loop_(new StateFeedbackLoop<2, 2, 2, Scalar>(
+          dt_config.make_v_drivetrain_loop())),
+      ttrust_(1.1),
+      wheel_(0.0),
+      throttle_(0.0),
+      quickturn_(false),
+      left_gear_(dt_config.default_high_gear ? Gear::HIGH : Gear::LOW),
+      right_gear_(dt_config.default_high_gear ? Gear::HIGH : Gear::LOW),
+      counter_(0),
+      dt_config_(dt_config) {
+  last_position_.Zero();
+  position_.Zero();
+}
+
+template <typename Scalar>
+Scalar PolyDrivetrain<Scalar>::MotorSpeed(
+    const constants::ShifterHallEffect &hall_effect, Scalar shifter_position,
+    Scalar velocity, Gear gear) {
+  const Scalar high_gear_speed =
+      velocity / dt_config_.high_gear_ratio / dt_config_.wheel_radius;
+  const Scalar low_gear_speed =
+      velocity / dt_config_.low_gear_ratio / dt_config_.wheel_radius;
+
+  if (shifter_position < hall_effect.clear_low) {
+    // We're in low gear, so return speed for that gear.
+    return low_gear_speed;
+  } else if (shifter_position > hall_effect.clear_high) {
+    // We're in high gear, so return speed for that gear.
+    return high_gear_speed;
+  }
+
+  // Not in gear, so speed-match to destination gear.
+  switch (gear) {
+    case Gear::HIGH:
+    case Gear::SHIFTING_UP:
+      return high_gear_speed;
+    case Gear::LOW:
+    case Gear::SHIFTING_DOWN:
+    default:
+      return low_gear_speed;
+      break;
+  }
+}
+
+template <typename Scalar>
+Gear PolyDrivetrain<Scalar>::UpdateSingleGear(Gear requested_gear,
+                                              Gear current_gear) {
+  const Gear shift_up =
+      (dt_config_.shifter_type == ShifterType::HALL_EFFECT_SHIFTER)
+          ? Gear::SHIFTING_UP
+          : Gear::HIGH;
+  const Gear shift_down =
+      (dt_config_.shifter_type == ShifterType::HALL_EFFECT_SHIFTER)
+          ? Gear::SHIFTING_DOWN
+          : Gear::LOW;
+  if (current_gear != requested_gear) {
+    if (IsInGear(current_gear)) {
+      if (requested_gear == Gear::HIGH) {
+        if (current_gear != Gear::HIGH) {
+          current_gear = shift_up;
+        }
+      } else {
+        if (current_gear != Gear::LOW) {
+          current_gear = shift_down;
+        }
+      }
+    } else {
+      if (requested_gear == Gear::HIGH && current_gear == Gear::SHIFTING_DOWN) {
+        current_gear = Gear::SHIFTING_UP;
+      } else if (requested_gear == Gear::LOW &&
+                 current_gear == Gear::SHIFTING_UP) {
+        current_gear = Gear::SHIFTING_DOWN;
+      }
+    }
+  }
+  return current_gear;
+}
+
+template <typename Scalar>
+void PolyDrivetrain<Scalar>::SetGoal(
+    const ::frc971::control_loops::DrivetrainQueue::Goal &goal) {
+  const Scalar wheel = goal.wheel;
+  const Scalar throttle = goal.throttle;
+  const bool quickturn = goal.quickturn;
+  const bool highgear = goal.highgear;
+
+  // Apply a sin function that's scaled to make it feel better.
+  const Scalar angular_range = M_PI_2 * dt_config_.wheel_non_linearity;
+
+  wheel_ = sin(angular_range * wheel) / sin(angular_range);
+  wheel_ = sin(angular_range * wheel_) / sin(angular_range);
+  wheel_ = 2.0 * wheel - wheel_;
+  quickturn_ = quickturn;
+
+  if (quickturn_) {
+    wheel_ *= dt_config_.quickturn_wheel_multiplier;
+  } else {
+    wheel_ *= dt_config_.wheel_multiplier;
+  }
+
+  static const Scalar kThrottleDeadband = 0.05;
+  if (::std::abs(throttle) < kThrottleDeadband) {
+    throttle_ = 0;
+  } else {
+    throttle_ = copysign(
+        (::std::abs(throttle) - kThrottleDeadband) / (1.0 - kThrottleDeadband),
+        throttle);
+  }
+
+  Gear requested_gear = highgear ? Gear::HIGH : Gear::LOW;
+
+  left_gear_ = UpdateSingleGear(requested_gear, left_gear_);
+  right_gear_ = UpdateSingleGear(requested_gear, right_gear_);
+}
+
+template <typename Scalar>
+void PolyDrivetrain<Scalar>::SetPosition(
+    const ::frc971::control_loops::DrivetrainQueue::Position *position,
+    Gear left_gear, Gear right_gear) {
+  left_gear_ = left_gear;
+  right_gear_ = right_gear;
+  last_position_ = position_;
+  position_ = *position;
+}
+
+template <typename Scalar>
+Scalar PolyDrivetrain<Scalar>::FilterVelocity(Scalar throttle) const {
+  const Eigen::Matrix<Scalar, 2, 2> FF =
+      loop_->plant().B().inverse() *
+      (Eigen::Matrix<Scalar, 2, 2>::Identity() - loop_->plant().A());
+
+  constexpr int kHighGearController = 3;
+  const Eigen::Matrix<Scalar, 2, 2> FF_high =
+      loop_->plant().coefficients(kHighGearController).B.inverse() *
+      (Eigen::Matrix<Scalar, 2, 2>::Identity() -
+       loop_->plant().coefficients(kHighGearController).A);
+
+  ::Eigen::Matrix<Scalar, 1, 2> FF_sum = FF.colwise().sum();
+  int min_FF_sum_index;
+  const Scalar min_FF_sum = FF_sum.minCoeff(&min_FF_sum_index);
+  const Scalar min_K_sum = loop_->controller().K().col(min_FF_sum_index).sum();
+  const Scalar high_min_FF_sum = FF_high.col(0).sum();
+
+  const Scalar 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);
+}
+
+template <typename Scalar>
+Scalar PolyDrivetrain<Scalar>::MaxVelocity() {
+  const Eigen::Matrix<Scalar, 2, 2> FF =
+      loop_->plant().B().inverse() *
+      (Eigen::Matrix<Scalar, 2, 2>::Identity() - loop_->plant().A());
+
+  constexpr int kHighGearController = 3;
+  const Eigen::Matrix<Scalar, 2, 2> FF_high =
+      loop_->plant().coefficients(kHighGearController).B.inverse() *
+      (Eigen::Matrix<Scalar, 2, 2>::Identity() -
+       loop_->plant().coefficients(kHighGearController).A);
+
+  ::Eigen::Matrix<Scalar, 1, 2> FF_sum = FF.colwise().sum();
+  int min_FF_sum_index;
+  const Scalar min_FF_sum = FF_sum.minCoeff(&min_FF_sum_index);
+  // const Scalar min_K_sum = loop_->K().col(min_FF_sum_index).sum();
+  const Scalar high_min_FF_sum = FF_high.col(0).sum();
+
+  const Scalar 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;
+}
+
+template <typename Scalar>
+void PolyDrivetrain<Scalar>::Update() {
+  if (dt_config_.loop_type == LoopType::CLOSED_LOOP) {
+    loop_->mutable_X_hat()(0, 0) = kf_->X_hat()(1, 0);
+    loop_->mutable_X_hat()(1, 0) = kf_->X_hat()(3, 0);
+  }
+
+  // TODO(austin): Observer for the current velocity instead of difference
+  // calculations.
+  ++counter_;
+
+  if (IsInGear(left_gear_) && IsInGear(right_gear_)) {
+    // FF * X = U (steady state)
+    const Eigen::Matrix<Scalar, 2, 2> FF =
+        loop_->plant().B().inverse() *
+        (Eigen::Matrix<Scalar, 2, 2>::Identity() - loop_->plant().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 Scalar fvel = FilterVelocity(throttle_);
+
+    const Scalar sign_svel = wheel_ * ((fvel > 0.0) ? 1.0 : -1.0);
+    Scalar steering_velocity;
+    if (quickturn_) {
+      steering_velocity = wheel_ * MaxVelocity();
+    } else {
+      steering_velocity = ::std::abs(fvel) * wheel_;
+    }
+    const Scalar left_velocity = fvel - steering_velocity;
+    const Scalar right_velocity = fvel + steering_velocity;
+    goal_left_velocity_ = left_velocity;
+    goal_right_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<Scalar, 1, 2> equality_k;
+      equality_k << 1 + sign_svel, -(1 - sign_svel);
+      const Scalar equality_w = 0.0;
+
+      // Construct a constraint on R by manipulating the constraint on U
+      ::aos::controls::HVPolytope<2, 4, 4, Scalar> R_poly_hv(
+          U_Poly_.static_H() * (loop_->controller().K() + FF),
+          U_Poly_.static_k() +
+              U_Poly_.static_H() * loop_->controller().K() * loop_->X_hat(),
+          (loop_->controller().K() + FF).inverse() *
+              ::aos::controls::ShiftPoints<2, 4, Scalar>(
+                  U_Poly_.StaticVertices(),
+                  loop_->controller().K() * loop_->X_hat()));
+
+      // Limit R back inside the box.
+      loop_->mutable_R() =
+          CoerceGoal<Scalar>(R_poly_hv, equality_k, equality_w, loop_->R());
+    }
+
+    const Eigen::Matrix<Scalar, 2, 1> FF_volts = FF * loop_->R();
+    const Eigen::Matrix<Scalar, 2, 1> U_ideal =
+        loop_->controller().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);
+    }
+
+    if (dt_config_.loop_type == LoopType::OPEN_LOOP) {
+      loop_->mutable_X_hat() =
+          loop_->plant().A() * loop_->X_hat() + loop_->plant().B() * loop_->U();
+    }
+
+    // Housekeeping: set the shifting logging values to zero, because we're not shifting
+    left_motor_speed_ = 0.0;
+    right_motor_speed_ = 0.0;
+    current_left_velocity_ = 0.0;
+    current_right_velocity_ = 0.0;
+  } else {
+    current_left_velocity_ =
+        (position_.left_encoder - last_position_.left_encoder) / dt_config_.dt;
+    current_right_velocity_ =
+        (position_.right_encoder - last_position_.right_encoder) /
+        dt_config_.dt;
+    left_motor_speed_ =
+        MotorSpeed(dt_config_.left_drive, position_.left_shifter_position,
+                   current_left_velocity_, left_gear_);
+    right_motor_speed_ =
+        MotorSpeed(dt_config_.right_drive, position_.right_shifter_position,
+                   current_right_velocity_, right_gear_);
+
+    goal_left_velocity_ = current_left_velocity_;
+    goal_right_velocity_ = current_right_velocity_;
+
+    // Any motor is not in gear. Speed match.
+    ::Eigen::Matrix<Scalar, 1, 1> R_left;
+    ::Eigen::Matrix<Scalar, 1, 1> R_right;
+    R_left(0, 0) = left_motor_speed_;
+    R_right(0, 0) = right_motor_speed_;
+
+    const Scalar wiggle =
+        (static_cast<Scalar>((counter_ % 30) / 15) - 0.5) * 8.0;
+
+    loop_->mutable_U(0, 0) = ::aos::Clip(
+        (R_left / dt_config_.v)(0, 0) + (IsInGear(left_gear_) ? 0 : wiggle),
+        -12.0, 12.0);
+    loop_->mutable_U(1, 0) = ::aos::Clip(
+        (R_right / dt_config_.v)(0, 0) + (IsInGear(right_gear_) ? 0 : wiggle),
+        -12.0, 12.0);
+#ifdef __linux__
+    loop_->mutable_U() *= 12.0 / ::aos::robot_state->voltage_battery;
+#endif  // __linux__
+  }
+}
+
+template <typename Scalar>
+void PolyDrivetrain<Scalar>::SetOutput(
+    ::frc971::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 = MaybeHigh(left_gear_);
+    output->right_high = MaybeHigh(right_gear_);
+  }
+}
+
+template <typename Scalar>
+void PolyDrivetrain<Scalar>::PopulateStatus(
+    ::frc971::control_loops::DrivetrainQueue::Status *status) {
+  status->left_velocity_goal = goal_left_velocity_;
+  status->right_velocity_goal = goal_right_velocity_;
+
+  status->cim_logging.left_in_gear = IsInGear(left_gear_);
+  status->cim_logging.left_motor_speed = left_motor_speed_;
+  status->cim_logging.left_velocity = current_left_velocity_;
+
+  status->cim_logging.right_in_gear = IsInGear(right_gear_);
+  status->cim_logging.right_motor_speed = right_motor_speed_;
+  status->cim_logging.right_velocity = current_right_velocity_;
+}
+
+
 }  // namespace drivetrain
 }  // namespace control_loops
 }  // namespace frc971