fw pos/att ctrl: pass manual nose wheel increments during takeoff ground roll

src/modules/fw_att_control/FixedwingAttitudeControl.cpp

@@ -556,6 +556,9 @@ void FixedwingAttitudeControl::Run()
 					if (wheel_control) {
 						yaw_u = _wheel_ctrl.control_bodyrate(dt, control_input);
 
+						// XXX: this is an abuse -- used to ferry manual yaw inputs from position controller during auto modes
+						yaw_u += _att_sp.yaw_sp_move_rate * _param_fw_man_y_sc.get();
+
 					} else {
 						yaw_u = _yaw_ctrl.control_euler_rate(dt, control_input, bodyrate_ff(2));
 					}

src/modules/fw_pos_control_l1/FixedwingPositionControl.cpp

@@ -1424,6 +1424,11 @@ FixedwingPositionControl::control_auto_takeoff(const hrt_abstime &now, const flo
 		// yaw control is disabled once in "taking off" state
 		_att_sp.fw_control_yaw = _runway_takeoff.controlYaw();
 
+		// XXX: hacky way to pass through manual nose-wheel incrementing. need to clean this interface.
+		if (_param_rwto_nudge.get()) {
+			_att_sp.yaw_sp_move_rate = _manual_control_setpoint.r;
+		}
+
 		// tune up the lateral position control guidance when on the ground
 		if (_att_sp.fw_control_yaw) {
 			_npfg.setPeriod(_param_rwto_l1_period.get());
@@ -2359,6 +2364,9 @@ FixedwingPositionControl::Run()
 		// by default we don't want yaw to be contoller directly with rudder
 		_att_sp.fw_control_yaw = false;
 
+		// default to zero - is used (IN A HACKY WAY) to pass direct nose wheel steering via yaw stick to the actuators during auto takeoff
+		_att_sp.yaw_sp_move_rate = 0.0f;
+
 		if (_control_mode_current != FW_POSCTRL_MODE_AUTO_LANDING) {
 			reset_landing_state();
 		}

src/modules/fw_pos_control_l1/FixedwingPositionControl.hpp

@@ -765,7 +765,8 @@ private:
 		(ParamFloat<px4::params::FW_WING_SPAN>) _param_fw_wing_span,
 		(ParamFloat<px4::params::FW_WING_HEIGHT>) _param_fw_wing_height,
 
-		(ParamFloat<px4::params::RWTO_L1_PERIOD>) _param_rwto_l1_period
+		(ParamFloat<px4::params::RWTO_L1_PERIOD>) _param_rwto_l1_period,
+		(ParamBool<px4::params::RWTO_NUDGE>) _param_rwto_nudge
 	)
 
 };

src/modules/fw_pos_control_l1/runway_takeoff/runway_takeoff_params.c

@@ -144,3 +144,11 @@ PARAM_DEFINE_FLOAT(RWTO_RAMP_TIME, 2.0f);
  * @group Runway Takeoff
  */
 PARAM_DEFINE_FLOAT(RWTO_L1_PERIOD, 5.0f);
+
+/**
+ * Enable use of yaw stick for nudging the wheel during runway ground roll
+ *
+ * @boolean
+ * @group Runway Takeoff
+ */
+PARAM_DEFINE_INT32(RWTO_NUDGE, 0);