mc_pos_control/FlightTask: apply nit-pick review findings

src/lib/flight_tasks/tasks/FlightTask/FlightTask.cpp

@@ -164,7 +164,7 @@ void FlightTask::_evaluateVehicleLocalPosition()
 
 void FlightTask::_evaluateDistanceToGround()
 {
-	// Altitude above ground is by default just the negation of the current local position in D-direction.
+	// Altitude above ground is local z-position or altitude above home or distance sensor altitude depending on what's available
 	_dist_to_ground = -_position(2);
 
 	if (PX4_ISFINITE(_dist_to_bottom)) {

src/lib/flight_tasks/tasks/FlightTask/FlightTask.hpp

@@ -211,7 +211,7 @@ protected:
 	matrix::Vector3f _position; /**< current vehicle position */
 	matrix::Vector3f _velocity; /**< current vehicle velocity */
 	float _yaw = 0.f; /**< current vehicle yaw heading */
-	float _dist_to_bottom = 0.0f; /**< current height above ground level */
+	float _dist_to_bottom = 0.f; /**< current height above ground level */
 	float _dist_to_ground = 0.f; /**< equals _dist_to_bottom if valid, height above home otherwise */
 
 	/**

src/modules/mc_pos_control/mc_pos_control_params.c

@@ -352,6 +352,7 @@ PARAM_DEFINE_FLOAT(MPC_LAND_SPEED, 0.7f);
 
 /**
  * Maximum horizontal velocity during landing
+ * Set the value higher than the otherwise expected maximum to disable any slowdown.
  *
  * @unit m/s
  * @min 0
@@ -692,11 +693,12 @@ PARAM_DEFINE_FLOAT(MPC_YAWRAUTO_MAX, 45.0f);
 /**
  * Altitude for 1. step of slow landing (descend)
  *
- * Below this altitude descending velocity gets limited
- * to a value between "MPC_Z_VEL_MAX" and "MPC_LAND_SPEED"
- * to enable a smooth descent experience.
- * The horizontal velocity also gets limited to a value
+ * Below this altitude:
+ * - descending velocity gets limited to a value
+ * between "MPC_Z_VEL_MAX" and "MPC_LAND_SPEED"
+ * - horizontal velocity gets limited to a value
  * between "MPC_VEL_MANUAL" and "MPC_LAND_VEL_XY"
+ * for a smooth descent and landing experience.
  * Value needs to be higher than "MPC_LAND_ALT2"
  *
  * @unit m