FlightTaskAutoMapper: clarify influence of sticks

src/lib/flight_tasks/tasks/AutoMapper/FlightTaskAutoMapper.cpp

@@ -180,22 +180,17 @@ bool FlightTaskAutoMapper::_highEnoughForLandingGear()
 
 float FlightTaskAutoMapper::_getLandSpeed()
 {
-	float speed = 0;
+	float land_speed = math::gradual(_dist_to_ground,
+					 _param_mpc_land_alt2.get(), _param_mpc_land_alt1.get(),
+					 _param_mpc_land_speed.get(), _constraints.speed_down);
 
-	if (_dist_to_ground > _param_mpc_land_alt1.get()) {
-		speed = _constraints.speed_down;
-
-	} else {
-		const float land_speed = math::gradual(_dist_to_ground,
-						       _param_mpc_land_alt2.get(), _param_mpc_land_alt1.get(),
-						       _param_mpc_land_speed.get(), _constraints.speed_down);
-
-		// user input assisted land speed
-		if (_param_mpc_land_rc_help.get()) {
-			_sticks.evaluateSticks(_time_stamp_current);
-			speed = land_speed + _sticks.getPositionExpo()(2) * land_speed;
-		}
+	// user input assisted land speed
+	if (_param_mpc_land_rc_help.get()
+	    && (_dist_to_ground < _param_mpc_land_alt1.get())
+	    && _sticks.evaluateSticks(_time_stamp_current)) {
+		// stick full up -1 -> stop, stick full down 1 -> double the speed
+		land_speed *= (1 + _sticks.getPositionExpo()(2));
 	}
 
-	return speed;
+	return land_speed;
 }

src/lib/flight_tasks/tasks/Utility/Sticks.cpp

@@ -43,7 +43,7 @@ Sticks::Sticks(ModuleParams *parent) :
 	ModuleParams(parent)
 {};
 
-void Sticks::evaluateSticks(hrt_abstime now)
+bool Sticks::evaluateSticks(hrt_abstime now)
 {
 	_sub_manual_control_setpoint.update();
 
@@ -80,6 +80,8 @@ void Sticks::evaluateSticks(hrt_abstime now)
 		_positions.zero();
 		_positions_expo.zero();
 	}
+
+	return _input_available;
 }
 
 void Sticks::applyGearSwitch(landing_gear_s &gear)

src/lib/flight_tasks/tasks/Utility/Sticks.hpp

@@ -53,7 +53,7 @@ public:
 	Sticks(ModuleParams *parent);
 	~Sticks() = default;
 
-	void evaluateSticks(hrt_abstime now); ///< checks and sets stick inputs
+	bool evaluateSticks(hrt_abstime now); ///< checks and sets stick inputs
 	void applyGearSwitch(landing_gear_s &gear); ///< Sets gears according to switch
 	bool isAvailable() { return _input_available; };
 	const matrix::Vector<float, 4> &getPosition() { return _positions; };

src/modules/mc_pos_control/mc_pos_control_params.c

@@ -359,8 +359,11 @@ PARAM_DEFINE_FLOAT(MPC_LAND_VEL_XY, 10.0f);
 
 /**
  * Enable user assisted descent speed for autonomous land routine.
- * When enabled, descent speed will be equal to MPC_LAND_SPEED at half throttle,
- * MPC_Z_VEL_MAX_DN at zero throttle, and 0.5 * MPC_LAND_SPEED at full throttle.
+ *
+ * When enabled, descent speed will be:
+ * stick full up - 0
+ * stick centered - MPC_LAND_SPEED
+ * stick full down - 2 * MPC_LAND_SPEED
  *
  * @min 0
  * @max 1