Pr add ground effect deadzone

[EliaTarasov]

• Adds the ability to enable/disable support for baro deadzone near ground.
• Adds default range for baro deadzone.

[priseborough]

Please provide a link to a log where you have tested this.

[priseborough]

The major problem with this is that it turns on ground effect compensation permanently when the parameter is set. This is not desirable because it can lead to significant height errors during normal flying. It should only be turned on for takeoff or when landing is expected. This should be done by the commander module.

When this has been done, please submit with test evidence that shows the feature working during landing and takeoff.

[mhkabir]

snake_case.

[EliaTarasov]

@mhkabir thanks!
@priseborough

The major problem with this is that it turns on ground effect compensation permanently when the parameter is set. This is not desirable because it can lead to significant height errors during normal flying. It should only be turned on for takeoff or when landing is expected. This should be done by the commander module.

Agree. But this feature should work in ALT/POS_CTL too. How to define if the landing is expected in these modes?
Thanks!

[EliaTarasov]

@mhkabir could you please give a hint?

It should only be turned on for takeoff or when landing is expected.

How to define if the landing is expected in ALT_CTL/POS_CTL modes when only baro is used for height estimation?

This should be done by the commander module.

I looked into commander module but didn't find much about.

[RomanBapst]

@priseborough @EliaTarasov I have implemented something similar and would like to bring it upstream.
I have extended the land detector to publish a flag called "in_ground_effect". The logic for that is quite simple but it basically checks if the vehicle is not moving horizontally and descending close to land speed.
The reason I added this to the land detector is because pretty much all of this logic is already in there. Of course you will always be able to fool the system since descending at landing speed would trigger the flag even if the vehicle is still far from the ground. Once could maybe add a bit more logic which does not trigger the flag if the vehicle is descending a lot faster than landing speed (assuming the user does not land by slamming the vehicle into the ground).

I think something that is missing additionally is the ability to use the terrain estimate to activate the baro innovation deadzone.