vtol fixes:

- mc pos control: publish attitude setpoint when vtol is in trans mode
- fw att control: do not publish attitude setpoint when in transition mode
- introduce flag in_transition_mode in vehicle status message for vtol
- improve tiltrotor code based on flight testing

msg/vehicle_status.msg

@@ -106,6 +106,7 @@ uint32 component_id			# subsystem / component id, inspired by MAVLink's componen
 bool is_rotary_wing			# True if system is in rotary wing configuration, so for a VTOL this is only true while flying as a multicopter
 bool is_vtol				# True if the system is VTOL capable
 bool vtol_fw_permanent_stab		# True if vtol should stabilize attitude for fw in manual mode
+bool in_transition_mode
 
 bool condition_battery_voltage_valid
 bool condition_system_in_air_restore		# true if we can restore in mid air

src/modules/commander/commander.cpp

@@ -1498,6 +1498,7 @@ int commander_thread_main(int argc, char *argv[])
 			/* Make sure that this is only adjusted if vehicle really is of type vtol*/
 			if (is_vtol(&status)) {
 				status.is_rotary_wing = vtol_status.vtol_in_rw_mode;
+				status.in_transition_mode = vtol_status.vtol_in_trans_mode;
 			}
 		}
 

src/modules/fw_att_control/fw_att_control_main.cpp

@@ -941,7 +941,7 @@ FixedwingAttitudeControl::task_main()
 					att_sp.thrust = throttle_sp;
 
 					/* lazily publish the setpoint only once available */
-					if (!_vehicle_status.is_rotary_wing) {
+					if (!_vehicle_status.is_rotary_wing && !_vehicle_status.in_transition_mode) {
 						if (_attitude_sp_pub != nullptr) {
 							/* publish the attitude setpoint */
 							orb_publish(ORB_ID(vehicle_attitude_setpoint), _attitude_sp_pub, &att_sp);

src/modules/mc_pos_control/mc_pos_control_main.cpp

@@ -1459,7 +1459,7 @@ MulticopterPositionControl::task_main()
 		if (!(_control_mode.flag_control_offboard_enabled &&
 					!(_control_mode.flag_control_position_enabled ||
 						_control_mode.flag_control_velocity_enabled))) {
-			if (_att_sp_pub != nullptr && _vehicle_status.is_rotary_wing) {
+			if (_att_sp_pub != nullptr && (_vehicle_status.is_rotary_wing || _vehicle_status.in_transition_mode)) {
 				orb_publish(ORB_ID(vehicle_attitude_setpoint), _att_sp_pub, &_att_sp);
 			} else if (_att_sp_pub == nullptr && _vehicle_status.is_rotary_wing){
 				_att_sp_pub = orb_advertise(ORB_ID(vehicle_attitude_setpoint), &_att_sp);

src/modules/vtol_att_control/tiltrotor.cpp

@@ -281,12 +281,12 @@ void Tiltrotor::update_transition_state()
 		// tilt rotors forward up to certain angle
 		if (_tilt_control <= _params_tiltrotor.tilt_transition ) {
 			_tilt_control = _params_tiltrotor.tilt_mc +
-				fabsf(_params_tiltrotor.tilt_transition - _params_tiltrotor.tilt_mc)*(float)hrt_elapsed_time(&_vtol_schedule.transition_start)/(_params_tiltrotor.front_trans_dur*1000000.0f);
+				fabsf(_params_tiltrotor.tilt_transition - _params_tiltrotor.tilt_mc) * (float)hrt_elapsed_time(&_vtol_schedule.transition_start)/(_params_tiltrotor.front_trans_dur * 1000000.0f);
 		}
 
 		// do blending of mc and fw controls
 		if (_airspeed->true_airspeed_m_s >= _params_tiltrotor.airspeed_blend_start) {
-			_mc_roll_weight = 1.0f - (_airspeed->true_airspeed_m_s - _params_tiltrotor.airspeed_blend_start) / (_params_tiltrotor.airspeed_trans - _params_tiltrotor.airspeed_blend_start);
+			_mc_roll_weight = 0.0f;
 		} else {
 			// at low speeds give full weight to mc
 			_mc_roll_weight = 1.0f;
@@ -301,18 +301,26 @@ void Tiltrotor::update_transition_state()
 	} else if (_vtol_schedule.flight_mode == TRANSITION_FRONT_P2) {
 		// the plane is ready to go into fixed wing mode, tilt the rotors forward completely
 		_tilt_control = _params_tiltrotor.tilt_transition +
-			fabsf(_params_tiltrotor.tilt_fw - _params_tiltrotor.tilt_transition)*(float)hrt_elapsed_time(&_vtol_schedule.transition_start)/(_params_tiltrotor.front_trans_dur_p2*1000000.0f);
+			fabsf(_params_tiltrotor.tilt_fw - _params_tiltrotor.tilt_transition) * (float)hrt_elapsed_time(&_vtol_schedule.transition_start)/(_params_tiltrotor.front_trans_dur_p2 * 1000000.0f);
 		_mc_roll_weight = 0.0f;
 	} else if (_vtol_schedule.flight_mode == TRANSITION_BACK) {
 		if (_rear_motors != IDLE) {
 			set_rear_motor_state(IDLE);
 		}
+
+		if (!flag_idle_mc) {
+			set_idle_mc();
+			flag_idle_mc = true;
+		}
 		// tilt rotors back
 		if (_tilt_control > _params_tiltrotor.tilt_mc) {
 			_tilt_control = _params_tiltrotor.tilt_fw -
-				fabsf(_params_tiltrotor.tilt_fw - _params_tiltrotor.tilt_mc)*(float)hrt_elapsed_time(&_vtol_schedule.transition_start)/(_params_tiltrotor.back_trans_dur*1000000.0f);
+				fabsf(_params_tiltrotor.tilt_fw - _params_tiltrotor.tilt_mc) * (float)hrt_elapsed_time(&_vtol_schedule.transition_start)/(_params_tiltrotor.back_trans_dur * 1000000.0f);
 		}
 
+		// set zero throttle for backtransition otherwise unwanted moments will be created
+		_actuators_mc_in->control[actuator_controls_s::INDEX_THROTTLE] = 0.0f;
+
 		_mc_roll_weight = 0.0f;
 
 	}