update quad vtol tailsitter mixer

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

ROMFS/px4fmu_common/mixers-sitl/quad_x_vtol.main.mix

@@ -3,6 +3,7 @@ Mixer for the gazebo tailsitter model
 
 R: 4x
 
+Z:
 Z:
 
 # left elevon

ROMFS/px4fmu_common/mixers/quad_x_vtol.main.mix

@@ -8,12 +8,15 @@ are mixed 100%.
 
 R: 4x
 
+Z:
+Z:
+
 # left elevon
 M: 2
-S: 1 0 -5000 -5000      0 -10000  10000
+S: 1 0  5000  5000      0 -10000  10000
 S: 1 1  5000  5000      0 -10000  10000
 
 # right elevon
 M: 2
-S: 1 0  -5000  -5000    0 -10000  10000
+S: 1 0   5000   5000    0 -10000  10000
 S: 1 1  -5000  -5000    0 -10000  10000

src/modules/vtol_att_control/tailsitter.cpp

@@ -44,7 +44,7 @@
 
 #include <uORB/topics/landing_gear.h>
 
-#define PITCH_TRANSITION_FRONT_P1 -1.1f	// pitch angle to switch to TRANSITION_P2
+#define PITCH_TRANSITION_FRONT_P1 -0.5f	// pitch angle to switch to TRANSITION_P2 (28°)
 #define PITCH_TRANSITION_BACK -0.25f	// pitch angle to switch to MC
 
 using namespace matrix;
@@ -146,6 +146,7 @@ void Tailsitter::update_vtol_state()
 
 				if (transition_to_fw) {
 					_vtol_schedule.flight_mode = vtol_mode::FW_MODE;
+					printf("transition to FW completed\n");
 				}
 
 				// check front transition timeout
@@ -335,12 +336,24 @@ void Tailsitter::fill_actuator_outputs()
 		// FW thrust is allocated on mc_thrust_sp[0] for tailsitter with dynamic control allocation
 		_thrust_setpoint_0->xyz[2] = -fw_in[actuator_controls_s::INDEX_THROTTLE];
 
-		/* allow differential thrust if enabled */
+		/* allow differential thrust for yaw if enabled */
 		if (_param_vt_fw_difthr_en.get()) {
 			mc_out[actuator_controls_s::INDEX_ROLL] = fw_in[actuator_controls_s::INDEX_YAW] * _param_vt_fw_difthr_sc.get() ;
 			_torque_setpoint_0->xyz[0] = fw_in[actuator_controls_s::INDEX_YAW] * _param_vt_fw_difthr_sc.get() ;
 		}
 
+		if (_param_vt_fw_difthr_r.get()) {
+			// enable differential thrust for fixed-wing roll control
+			mc_out[actuator_controls_s::INDEX_YAW] = -fw_in[actuator_controls_s::INDEX_ROLL];
+			_torque_setpoint_0->xyz[2] = fw_in[actuator_controls_s::INDEX_ROLL];
+		}
+
+		if (_param_vt_fw_difthr_p.get()) {
+			// enable differential thrust for fixed-wing pitch control
+			mc_out[actuator_controls_s::INDEX_PITCH] = fw_in[actuator_controls_s::INDEX_PITCH];
+			_torque_setpoint_0->xyz[1] = fw_in[actuator_controls_s::INDEX_PITCH];
+		}
+
 	} else {
 		_torque_setpoint_0->xyz[0] = mc_in[actuator_controls_s::INDEX_ROLL];
 		_torque_setpoint_0->xyz[1] = mc_in[actuator_controls_s::INDEX_PITCH];
@@ -363,10 +376,25 @@ void Tailsitter::fill_actuator_outputs()
 		fw_out[actuator_controls_s::INDEX_PITCH] = 0;
 
 	} else {
-		fw_out[actuator_controls_s::INDEX_ROLL]  = fw_in[actuator_controls_s::INDEX_ROLL];
-		fw_out[actuator_controls_s::INDEX_PITCH] = fw_in[actuator_controls_s::INDEX_PITCH];
-		_torque_setpoint_1->xyz[1] = fw_in[actuator_controls_s::INDEX_PITCH];
-		_torque_setpoint_1->xyz[2] = -fw_in[actuator_controls_s::INDEX_ROLL];
+		if (_param_vt_elev_lock.get()) {
+			// lock the elevator always
+			fw_out[actuator_controls_s::INDEX_PITCH] = 0.0f;
+			_torque_setpoint_1->xyz[1] = 0.0f;
+
+		} else {
+			fw_out[actuator_controls_s::INDEX_PITCH] = fw_in[actuator_controls_s::INDEX_PITCH];
+			_torque_setpoint_1->xyz[1] = fw_in[actuator_controls_s::INDEX_PITCH];
+		}
+
+		if (_param_vt_ail_fw_lock.get() && _vtol_schedule.flight_mode != vtol_mode::MC_MODE) {
+			// lock the ailerons in transition and fixed-wing
+			fw_out[actuator_controls_s::INDEX_ROLL]  = 0.0f;
+			_torque_setpoint_1->xyz[2] = 0.0f;
+
+		} else {
+			fw_out[actuator_controls_s::INDEX_ROLL]  = fw_in[actuator_controls_s::INDEX_ROLL];
+			_torque_setpoint_1->xyz[2] = -fw_in[actuator_controls_s::INDEX_ROLL];
+		}
 	}
 
 	_actuators_out_0->timestamp_sample = _actuators_mc_in->timestamp_sample;

src/modules/vtol_att_control/tailsitter.h

@@ -81,7 +81,11 @@ private:
 	void parameters_update() override;
 
 	DEFINE_PARAMETERS_CUSTOM_PARENT(VtolType,
-					(ParamFloat<px4::params::FW_PSP_OFF>) _param_fw_psp_off
+					(ParamFloat<px4::params::FW_PSP_OFF>) _param_fw_psp_off,
+					(ParamInt<px4::params::VT_FW_DIFTHR_P>) _param_vt_fw_difthr_p,
+					(ParamInt<px4::params::VT_FW_DIFTHR_R>) _param_vt_fw_difthr_r,
+					(ParamInt<px4::params::VT_ELEV_LOCK>) _param_vt_elev_lock,
+					(ParamInt<px4::params::VT_AIL_FW_LOCK>) _param_vt_ail_fw_lock
 				       )
 
 

src/modules/vtol_att_control/vtol_att_control_params.c

@@ -75,6 +75,22 @@ PARAM_DEFINE_INT32(VT_TYPE, 0);
  */
 PARAM_DEFINE_INT32(VT_ELEV_MC_LOCK, 1);
 
+/**
+ * Lock elevator action always
+ *
+ * @boolean
+ * @group VTOL Attitude Control
+ */
+PARAM_DEFINE_INT32(VT_ELEV_LOCK, 1);
+
+/**
+ * Lock ailerons in transition and fixed-wing modes
+ *
+ * @boolean
+ * @group VTOL Attitude Control
+ */
+PARAM_DEFINE_INT32(VT_AIL_FW_LOCK, 0);
+
 /**
  * Duration of a front transition
  *
@@ -297,6 +313,30 @@ PARAM_DEFINE_INT32(VT_MOT_ID, 0);
  */
 PARAM_DEFINE_INT32(VT_FW_DIFTHR_EN, 0);
 
+/**
+ * Differential thrust in forwards flight for pitch.
+ *
+ * Set to 1 to enable differential thrust in fixed-wing flight.
+ *
+ * @min 0
+ * @max 1
+ * @decimal 0
+ * @group VTOL Attitude Control
+ */
+PARAM_DEFINE_INT32(VT_FW_DIFTHR_P, 1);
+
+/**
+ * Differential thrust in forwards flight for roll.
+ *
+ * Set to 1 to enable differential thrust in fixed-wing flight.
+ *
+ * @min 0
+ * @max 1
+ * @decimal 0
+ * @group VTOL Attitude Control
+ */
+PARAM_DEFINE_INT32(VT_FW_DIFTHR_R, 1);
+
 /**
  * Differential thrust scaling factor
  *