Omni Pos-Ctrl: Reduced jerking when a large command is given in offboard

- OMNI_ATT_MODE = 2 uses OMNI_DFC_MAX_THR parameter to limit the horizontal commanded thrust now
- Other modes are not affected

src/modules/mc_pos_control/PositionControl/PositionControl.cpp

@@ -89,7 +89,7 @@ bool PositionControl::setInputSetpoint(const vehicle_local_position_setpoint_s &
 	return mapping_succeeded;
 }
 
-void PositionControl::setConstraints(const vehicle_constraints_s &constraints)
+void PositionControl::setConstraints(const vehicle_constraints_s &constraints, const float lim_thr_hor_max)
 {
 	_constraints = constraints;
 
@@ -107,6 +107,8 @@ void PositionControl::setConstraints(const vehicle_constraints_s &constraints)
 		_constraints.speed_down = _lim_vel_down;
 	}
 
+	_lim_thr_hor_max = lim_thr_hor_max;
+
 	// ignore _constraints.speed_xy TODO: remove it completely as soon as no task uses it anymore to avoid confusion
 }
 
@@ -321,6 +323,7 @@ void PositionControl::_velocityControl(const float dt)
 		float thrust_max_NE_tilt = fabsf(_thr_sp(2)) * tanf(_constraints.tilt);
 		float thrust_max_NE = sqrtf(_lim_thr_max * _lim_thr_max - _thr_sp(2) * _thr_sp(2));
 		thrust_max_NE = math::min(thrust_max_NE_tilt, thrust_max_NE);
+		thrust_max_NE = math::min(_lim_thr_hor_max, thrust_max_NE);
 
 		// Saturate thrust in NE-direction.
 		_thr_sp(0) = thrust_desired_NE(0);

src/modules/mc_pos_control/PositionControl/PositionControl.hpp

@@ -137,8 +137,9 @@ public:
 	 * Pass constraints that are stricter than the global limits
 	 * Note: NAN value means no constraint, take maximum limit of controller.
 	 * @param constraints a PositionControl structure with supported constraints
+	 * @param lim_thr_hor_max maximum horizontal thrust (read from parameter for OMNI_ATT_MODE = 2, otherwise = 1.0F)
 	 */
-	void setConstraints(const vehicle_constraints_s &constraints);
+	void setConstraints(const vehicle_constraints_s &constraints, const float lim_thr_hor_max);
 
 	/**
 	 * Apply P-position and PID-velocity controller that updates the member
@@ -207,6 +208,7 @@ private:
 	float _lim_thr_min{}; ///< Minimum collective thrust allowed as output [-1,0] e.g. -0.9
 	float _lim_thr_max{}; ///< Maximum collective thrust allowed as output [-1,0] e.g. -0.1
 	float _lim_tilt{}; ///< Maximum tilt from level the output attitude is allowed to have
+	float _lim_thr_hor_max; ///< Maximum direct-force horizontal thrust allowed as output [0, 1]
 
 	float _hover_thrust{}; ///< Thrust [0,1] with which the vehicle hovers not aacelerating down or up with level orientation
 

src/modules/mc_pos_control/mc_pos_control_main.cpp

@@ -647,7 +647,9 @@ MulticopterPositionControl::Run()
 
 			// Run position control
 			_control.setState(_states);
-			_control.setConstraints(constraints);
+
+			float max_hor_thrust = (_param_omni_att_mode.get() == 2) ? _param_omni_dfc_max_thr.get() : 1.0F;
+			_control.setConstraints(constraints, max_hor_thrust);
 
 			if (!_control.setInputSetpoint(setpoint)) {
 				warn_rate_limited("PositionControl: invalid setpoints");