Control Allocation: add option to disable yaw by differential thrust

This replaces the propeller_torque_disabled flag to disable yaw by differential thrust
for tiltrotor and tailsitter VTOLs, as propeller_torque_disabled is not enough to set
effectiveness of an acutator in the yaw axis to 0 in case it's tilted.

Signed-off-by: Silvan Fuhrer <silvan@auterion.com>

src/modules/control_allocator/ActuatorEffectiveness/ActuatorEffectivenessMCTilt.cpp

@@ -51,7 +51,7 @@ ActuatorEffectivenessMCTilt::getEffectivenessMatrix(Configuration &configuration
 	}
 
 	// MC motors
-	_mc_rotors.enablePropellerTorque(!_tilts.hasYawControl());
+	_mc_rotors.enableYawByDifferentialThrust(!_tilts.hasYawControl());
 	const bool rotors_added_successfully = _mc_rotors.addActuators(configuration);
 
 	// Tilts

src/modules/control_allocator/ActuatorEffectiveness/ActuatorEffectivenessRotors.cpp

@@ -213,6 +213,11 @@ ActuatorEffectivenessRotors::computeEffectivenessMatrix(const Geometry &geometry
 			effectiveness(j + 3, i + actuator_start_index) = thrust(j);
 		}
 
+		if (geometry.yaw_by_differential_thrust_disabled) {
+			// set yaw effectiveness to 0 if yaw is controlled by other means (e.g. tilts)
+			effectiveness(2, i + actuator_start_index) = 0.f;
+		}
+
 		if (geometry.three_dimensional_thrust_disabled) {
 			// Special case tiltrotor: instead of passing a 3D thrust vector (that would mostly have a x-component in FW, and z in MC),
 			// pass the vector magnitude as z-component, plus the collective tilt. Passing 3D thrust plus tilt is not feasible as they

src/modules/control_allocator/ActuatorEffectiveness/ActuatorEffectivenessRotors.hpp

@@ -74,6 +74,7 @@ public:
 		RotorGeometry rotors[NUM_ROTORS_MAX];
 		int num_rotors{0};
 		bool propeller_torque_disabled{false};
+		bool yaw_by_differential_thrust_disabled{false};
 		bool propeller_torque_disabled_non_upwards{false}; ///< keeps propeller torque enabled for upward facing motors
 		bool three_dimensional_thrust_disabled{false}; ///< for handling of tiltrotor VTOL, as they pass in 1D thrust and collective tilt
 	};
@@ -119,6 +120,8 @@ public:
 
 	void enablePropellerTorque(bool enable) { _geometry.propeller_torque_disabled = !enable; }
 
+	void enableYawByDifferentialThrust(bool enable) { _geometry.yaw_by_differential_thrust_disabled = !enable; }
+
 	void enablePropellerTorqueNonUpwards(bool enable) { _geometry.propeller_torque_disabled_non_upwards = !enable; }
 
 	void enableThreeDimensionalThrust(bool enable) { _geometry.three_dimensional_thrust_disabled = !enable; }

src/modules/control_allocator/ActuatorEffectiveness/ActuatorEffectivenessTailsitterVTOL.cpp

@@ -56,7 +56,8 @@ ActuatorEffectivenessTailsitterVTOL::getEffectivenessMatrix(Configuration &confi
 
 	// MC motors
 	configuration.selected_matrix = 0;
-	_mc_rotors.enablePropellerTorque(_mc_rotors.geometry().num_rotors > 3); // enable MC yaw control if more than 3 rotors
+	// enable MC yaw control if more than 3 rotors
+	_mc_rotors.enableYawByDifferentialThrust(_mc_rotors.geometry().num_rotors > 3);
 	const bool mc_rotors_added_successfully = _mc_rotors.addActuators(configuration);
 
 	// Control Surfaces

src/modules/control_allocator/ActuatorEffectiveness/ActuatorEffectivenessTiltrotorVTOL.cpp

@@ -60,7 +60,7 @@ ActuatorEffectivenessTiltrotorVTOL::getEffectivenessMatrix(Configuration &config
 
 	// MC motors
 	configuration.selected_matrix = 0;
-	_mc_rotors.enablePropellerTorque(!_tilts.hasYawControl());
+	_mc_rotors.enableYawByDifferentialThrust(!_tilts.hasYawControl());
 	_mc_rotors.enableThreeDimensionalThrust(false);
 
 	// Update matrix with tilts in vertical position when update is triggered by a manual