FlightTaskManualAltitude: Follow altitude limit given by the estimator

[bresch]

Describe problem solved by this pull request
The altitude agl is limited by the sonar range when taking off without GPS aiding, even if it is gained in air because the constraint is only updated on activate.

Describe your solution
Continuously track the constraint sent by the estimator

Describe possible alternatives
This function should be virtual and the horizontal limits updated in FlightTaskManualPosition

Test data / coverage
SITL tests with flow and intermittent GPS
https://logs.px4.io/plot_app?log=f60d771e-3008-4b44-8d96-2476e7c38c8b

[MaEtUgR]

Suggested change

	_min_speed_down = _constraints.speed_down;
	_max_speed_down = _constraints.speed_down;

The name confuses me since if I read min_speed_down I'm assuming you have to fly a certain minimum speed to descend... well, it wasn't your decision.

[bresch]

Totally agree, I made a 2nd commit to rename that.

[bresch]

@MaEtUgR Can you approve again please?

[MaEtUgR]

Looks correct to me, seems to work looking at the plot.

[bresch]

@PX4/testflights Can you fly that please?
Do you have a multicopter with optical flow and range finder? If yes, please try that:

• Make sure you have optical flow and GPS fusion enabled in EKF2_AID_MASK
• Takeoff in position to an altitude above the max distance of the range finder
• Disable GPS fusion in EKF2_AID_MASK (it will tell that you need to reboot to have an effect, but that will still work), the drone should go down by itself to the maximum altitude of the range finder
• Try to raise the throttle stick to gain altitude (the drone shouldn't be able to climb)
• Enable GPS fusion in EKF2_AID_MASK, wait a few seconds
• Try to raise the throttle stick to gain altitude (the drone should climb)

Thanks in advance.

[bresch]

Ping @PX4/testflights

[Tony3dr]

@bresch, unfortunately, we don't have a setup with optical flow or range finder.

[codecov]

Codecov Report

Merging #13958 into master will increase coverage by 0.17%.
The diff coverage is 33.47%.

@@            Coverage Diff             @@
##           master   #13958      +/-   ##
==========================================
+ Coverage   35.97%   36.14%   +0.17%     
==========================================
  Files         574      545      -29     
  Lines       48714    46887    -1827     
==========================================
- Hits        17523    16947     -576     
+ Misses      31191    29940    -1251

Flag	Coverage Δ
#mavsdk	36.14% <33.47%> (?)
#sitl_mission_FW	?
#sitl_mission_MC_box	?
#sitl_mission_MC_offboard_att	?
#sitl_mission_MC_offboard_pos	?
#sitl_mission_Rover	?
#sitl_mission_VTOL_standard	?
#sitl_mission_VTOL_tailsitter	?
#sitl_python_FW	?
#sitl_python_MC_box	?
#sitl_python_MC_offboard_att	?
#sitl_python_MC_offboard_pos	?
#sitl_python_Rover	?
#sitl_python_VTOL_standard	?
#sitl_python_VTOL_tailsitter	?

Impacted Files	Coverage Δ
src/modules/navigator/navigator_main.cpp	48.86% <ø> (+5.83%)	⬆️
src/modules/rc_update/rc_update.h	0% <ø> (ø)	⬆️
...ehicle_angular_velocity/VehicleAngularVelocity.hpp	100% <ø> (ø)	⬆️
.../modules/navigator/mission_feasibility_checker.cpp	34.49% <ø> (-19.31%)	⬇️
src/modules/uORB/SubscriptionCallback.hpp	83.33% <ø> (ø)	⬆️
src/modules/mavlink/mavlink_messages.cpp	71.71% <ø> (+4.17%)	⬆️
...c/modules/vtol_att_control/vtol_att_control_main.h	94.11% <ø> (ø)	⬆️
src/modules/commander/state_machine_helper.cpp	36.92% <ø> (+8.71%)	⬆️
src/modules/logger/logged_topics.cpp	70.77% <ø> (-0.53%)	⬇️
src/modules/logger/logger.cpp	65.01% <ø> (+0.55%)	⬆️
... and 195 more

[bresch]

This had enough testing on my side

[nicovanduijn]

This fixes #13350