VelocitySmoothing: simplify the API & fix style

src/lib/FlightTasks/tasks/ManualPositionSmoothVel/FlightTaskManualPositionSmoothVel.cpp

@@ -60,8 +60,6 @@ void FlightTaskManualPositionSmoothVel::_updateSetpoints()
 	_smoothing[1].setMaxAccel(MPC_ACC_HOR_MAX.get());
 	_smoothing[0].setMaxVel(_constraints.speed_xy);
 	_smoothing[1].setMaxVel(_constraints.speed_xy);
-	_smoothing[0].setDt(_deltatime);
-	_smoothing[1].setDt(_deltatime);
 
 	Vector2f vel_xy = Vector2f(&_velocity(0));
 	float jerk = _jerk_max.get();
@@ -78,7 +76,7 @@ void FlightTaskManualPositionSmoothVel::_updateSetpoints()
 
 	for (int i = 0; i < 2; ++i) {
 		_smoothing[i].setMaxJerk(jerk);
-		_smoothing[i].updateDurations(_velocity_setpoint(i));
+		_smoothing[i].updateDurations(_deltatime, _velocity_setpoint(i));
 	}
 
 	VelocitySmoothing::timeSynchronization(_smoothing, 2);

src/lib/FlightTasks/tasks/Utility/VelocitySmoothing.cpp

@@ -92,7 +92,7 @@ float VelocitySmoothing::computeT1(float T123, float accel_prev, float vel_prev,
 	float a = -max_jerk;
 	float b = max_jerk * T123 - accel_prev;
 	float delta = T123 * T123 * max_jerk * max_jerk + 2.f * T123 * accel_prev * max_jerk - accel_prev * accel_prev
-	  + 4.f * max_jerk * (vel_prev - vel_setpoint);
+		      + 4.f * max_jerk * (vel_prev - vel_setpoint);
 
 	float sqrt_delta = sqrtf(delta);
 	float denominator_inv = 1.f / (2.f * a);
@@ -106,9 +106,11 @@ float VelocitySmoothing::computeT1(float T123, float accel_prev, float vel_prev,
 	float T13_minus = T1_minus + T3_minus;
 
 	float T1 = 0.f;
+
 	if (T13_plus > T123) {
 		T1 = T1_minus;
-	} else if (T13_minus > T123){
+
+	} else if (T13_minus > T123) {
 		T1 = T1_plus;
 	}
 
@@ -161,18 +163,26 @@ void VelocitySmoothing::integrateT(float jerk, float accel_prev, float vel_prev,
 	pos_out = _dt / 3.f * (vel_out + accel_prev * _dt * 0.5f + 2.f * vel_prev) + _pos;
 }
 
-void VelocitySmoothing::updateDurations(float vel_setpoint, float T123)
+void VelocitySmoothing::updateDurations(float dt, float vel_setpoint)
+{
+	_vel_sp = vel_setpoint;
+	_dt = dt;
+	updateDurations();
+}
+
+void VelocitySmoothing::updateDurations(float T123)
 {
 	float T1, T2, T3;
 
 	/* Depending of the direction, start accelerating positively or negatively */
-	_max_jerk_T1 = (vel_setpoint - _vel > 0.f) ? _max_jerk : -_max_jerk;
+	_max_jerk_T1 = (_vel_sp - _vel > 0.f) ? _max_jerk : -_max_jerk;
 
 	// compute increasing acceleration time
 	if (PX4_ISFINITE(T123)) {
-		T1 = computeT1(T123, _accel, _vel, vel_setpoint, _max_jerk_T1);
+		T1 = computeT1(T123, _accel, _vel, _vel_sp, _max_jerk_T1);
+
 	} else {
-		T1 = computeT1(_accel, _vel, vel_setpoint, _max_jerk_T1);
+		T1 = computeT1(_accel, _vel, _vel_sp, _max_jerk_T1);
 	}
 
 	/* Force T1/2/3 to zero if smaller than an epoch to avoid chattering */
@@ -190,8 +200,9 @@ void VelocitySmoothing::updateDurations(float vel_setpoint, float T123)
 	// compute constant acceleration time
 	if (PX4_ISFINITE(T123)) {
 		T2 = computeT2(T123, T1, T3);
+
 	} else {
-		T2 = computeT2(T1, T3, _accel, _vel, vel_setpoint, _max_jerk_T1);
+		T2 = computeT2(T1, T3, _accel, _vel, _vel_sp, _max_jerk_T1);
 	}
 
 	if (T2 < _dt) {
@@ -201,11 +212,10 @@ void VelocitySmoothing::updateDurations(float vel_setpoint, float T123)
 	_T1 = T1;
 	_T2 = T2;
 	_T3 = T3;
-	_vel_sp = vel_setpoint;
 }
 
 void VelocitySmoothing::integrate(float pos, float &vel_setpoint_smooth,
-			       float &pos_setpoint_smooth)
+				  float &pos_setpoint_smooth)
 {
 	/* Integrate the trajectory */
 	float accel_new, vel_new, pos_new;
@@ -240,22 +250,24 @@ void VelocitySmoothing::integrate(float pos, float &vel_setpoint_smooth,
 	pos_setpoint_smooth = _pos;
 }
 
-void VelocitySmoothing::timeSynchronization(VelocitySmoothing traj[3], int n_traj)
+void VelocitySmoothing::timeSynchronization(VelocitySmoothing *traj, int n_traj)
 {
 	float desired_time = 0.f;
 	int longest_traj_index = 0;
 
 	for (int i = 0; i < n_traj; i++) {
 		const float T123 = traj[i].getTotalTime();
+
 		if (T123 > desired_time) {
 			desired_time = T123;
 			longest_traj_index = i;
 		}
 	}
+
 	if (desired_time > FLT_EPSILON) {
 		for (int i = 0; i < n_traj; i++) {
 			if (i != longest_traj_index) {
-				traj[i].updateDurations(traj[i].getVelSp(), desired_time);
+				traj[i].updateDurations(desired_time);
 			}
 		}
 	}

src/lib/FlightTasks/tasks/Utility/VelocitySmoothing.hpp

@@ -68,12 +68,12 @@ public:
 	void reset(float accel, float vel, float pos);
 
 	/**
-	 * Compute T1, T2, T3 depending on the current state and velocity setpoint. This should be called on every cycle.
+	 * Compute T1, T2, T3 depending on the current state and velocity setpoint. This should be called on every cycle
+	 * and before integrate().
+	 * @param dt delta time between last updateDurations() call and now [s]
 	 * @param vel_setpoint velocity setpoint input
-	 * @param T123 optional parameter. If set, the total trajectory time will be T123, if not,
-	 * 		the algorithm optimizes for time.
 	 */
-	void updateDurations(float vel_setpoint, float T123 = NAN);
+	void updateDurations(float dt, float vel_setpoint);
 
 	/**
 	 * Generate the trajectory (acceleration, velocity and position) by integrating the current jerk
@@ -93,22 +93,25 @@ public:
 	float getMaxVel() const { return _max_vel; }
 	void setMaxVel(float max_vel) { _max_vel = max_vel; }
 
-	/* Other getters and setters */
-	float getTotalTime() const {return _T1 + _T2 + _T3; }
-	float getVelSp() const {return _vel_sp; }
-
-	void setDt(float dt) {_dt = dt; } // delta time between last update() call and now [s]
-
 	/**
 	 * Synchronize several trajectories to have the same total time. This is required to generate
 	 * straight lines.
 	 * The resulting total time is the one of the longest trajectory.
-	 * @param traj[3] a table of VelocitySmoothing objects
-	 * n_traj the number of trajectories to be synchronized
+	 * @param traj an array of VelocitySmoothing objects
+	 * @param n_traj the number of trajectories to be synchronized
 	 */
-	static void timeSynchronization(VelocitySmoothing traj[3], int n_traj);
+	static void timeSynchronization(VelocitySmoothing *traj, int n_traj);
 
 private:
+	float getTotalTime() const { return _T1 + _T2 + _T3; }
+	float getVelSp() const { return _vel_sp; }
+
+	/**
+	 * Compute T1, T2, T3 depending on the current state and velocity setpoint.
+	 * @param T123 optional parameter. If set, the total trajectory time will be T123, if not,
+	 * 		the algorithm optimizes for time.
+	 */
+	void updateDurations(float T123 = NAN);
 	/**
 	 * Compute increasing acceleration time
 	 */
@@ -136,6 +139,10 @@ private:
 	inline void integrateT(float jerk, float accel_prev, float vel_prev, float pos_prev,
 			       float &accel_out, float &vel_out, float &pos_out);
 
+	/* Inputs */
+	float _vel_sp;
+	float _dt = 0.f;
+
 	/* Constraints */
 	float _max_jerk = 22.f;
 	float _max_accel = 8.f;
@@ -150,12 +157,9 @@ private:
 	float _max_jerk_T1 = 0.f; ///< jerk during phase T1 (with correct sign)
 
 	/* Duration of each phase */
-	float _T1 = 0.f; // Increasing acceleration
-	float _T2 = 0.f; // Constant acceleration
-	float _T3 = 0.f; // Decreasing acceleration
-
-	float _vel_sp;
-	float _dt = 0.f;
+	float _T1 = 0.f; ///< Increasing acceleration [s]
+	float _T2 = 0.f; ///< Constant acceleration [s]
+	float _T3 = 0.f; ///< Decreasing acceleration [s]
 
 	static constexpr float max_pos_err = 1.f; ///< maximum position error (if above, the position setpoint is locked)
 };