rover: replace RX_MAX_THR_YAW_R with a correction factor RO_YAW_RATE_CORR

src/lib/rover_control/RoverControl.cpp

@@ -161,7 +161,8 @@ float speedControl(SlewRate<float> &speed_with_rate_limit, PID &pid_speed, const
 }
 
 float rateControl(SlewRate<float> &adjusted_yaw_rate_setpoint, PID &pid_yaw_rate, const float yaw_rate_setpoint,
-		  const float vehicle_yaw_rate, const float max_thr_yaw_r, const float max_yaw_accel, const float max_yaw_decel,
+		  const float vehicle_yaw_rate, const float max_thr_speed, const float yaw_rate_corr, const float max_yaw_accel,
+		  const float max_yaw_decel,
 		  const float wheel_track, const float dt)
 {
 	// Apply acceleration and deceleration limit
@@ -194,11 +195,11 @@ float rateControl(SlewRate<float> &adjusted_yaw_rate_setpoint, PID &pid_yaw_rate
 	// Transform yaw rate into speed difference
 	float speed_diff_normalized{0.f};
 
-	if (wheel_track > FLT_EPSILON && max_thr_yaw_r > FLT_EPSILON) { // Feedforward
-		const float speed_diff = adjusted_yaw_rate_setpoint.getState() * wheel_track /
-					 2.f;
-		speed_diff_normalized = math::interpolate<float>(speed_diff, -max_thr_yaw_r,
-					max_thr_yaw_r, -1.f, 1.f);
+	if (wheel_track > FLT_EPSILON && max_thr_speed > FLT_EPSILON) { // Feedforward
+		const float speed_diff = (adjusted_yaw_rate_setpoint.getState() * wheel_track /
+					  2.f) * yaw_rate_corr;
+		speed_diff_normalized = math::interpolate<float>(speed_diff, -max_thr_speed,
+					max_thr_speed, -1.f, 1.f);
 	}
 
 	// Feedback control

src/lib/rover_control/RoverControl.hpp

@@ -100,7 +100,8 @@ float speedControl(SlewRate<float> &speed_with_rate_limit, PID &pid_speed, float
  * @param pid_yaw_rate Yaw rate PID (Updated by this function).
  * @param yaw_rate_setpoint Yaw rate setpoint [rad/s].
  * @param vehicle_yaw_rate Measured vehicle yaw rate [rad/s].
- * @param max_thr_yaw_r Yaw rate turning left/right wheels at max speed in opposite directions [m/s].
+ * @param max_thr_speed Speed at maximum throttle [m/s].
+ * @param yaw_rate_corr Yaw rate correction factor to convert yaw rate to speed difference.
  * @param max_yaw_accel Maximum allowed yaw acceleration [rad/s^2].
  * @param max_yaw_decel Maximum allowed yaw deceleration [rad/s^2].
  * @param wheel_track Distance from the center of the right wheel to the center of the left wheel [m].
@@ -108,7 +109,8 @@ float speedControl(SlewRate<float> &speed_with_rate_limit, PID &pid_speed, float
  * @return Normalized speed difference setpoint [-1, 1].
  */
 float rateControl(SlewRate<float> &adjusted_yaw_rate_setpoint, PID &pid_yaw_rate,
-		  float yaw_rate_setpoint, float vehicle_yaw_rate, float max_thr_yaw_r, float max_yaw_accel, float max_yaw_decel,
+		  float yaw_rate_setpoint, float vehicle_yaw_rate, float max_thr_speed, float yaw_rate_corr, float max_yaw_accel,
+		  float max_yaw_decel,
 		  float wheel_track, float dt);
 
 /**

src/lib/rover_control/rovercontrol_params.c

@@ -131,6 +131,22 @@ PARAM_DEFINE_FLOAT(RO_YAW_ACCEL_LIM, -1.f);
  */
 PARAM_DEFINE_FLOAT(RO_YAW_DECEL_LIM, -1.f);
 
+/**
+ * Yaw rate correction factor
+ *
+ * Multiplicative correction factor for the feedforward mapping of the yaw rate controller.
+ * Increase this value (x > 1) if the measured yaw rate is lower than the setpoint, decrease (0 < x < 1) otherwise.
+ * Note: Tuning this is particularly useful for skid-steered rovers, or rovers with misaligned wheels/steering axes
+ * that cause a lot of friction when turning.
+ *
+ * @min 0.01
+ * @max 10000
+ * @increment 0.01
+ * @decimal 2
+ * @group Rover Rate Control
+ */
+PARAM_DEFINE_FLOAT(RO_YAW_RATE_CORR, 1.f);
+
 /**
  * Proportional gain for closed loop yaw controller
  *