EKF: only set in_air flag true if not landed and armed

[CarlOlsson]

Describe problem solved by the proposed pull request
If the user carries the vehicle around the landed flag might be false. Without this change that could result in the EKF initializing the earth magnetic field states and commencing 3D axis mag fusion when still close to the ground.

[mhkabir]

This should go into the land detector, not here, I feel.

[dagar]

It partially is already. https://github.com/PX4/Firmware/blob/master/src/modules/land_detector/MulticopterLandDetector.cpp#L205-L208

https://github.com/PX4/Firmware/blob/master/src/modules/land_detector/FixedwingLandDetector.cpp#L98

What's missing?

[CarlOlsson]

Sorry, on our codebase vehicle_land_detected.landed can be true even if the vehicle is not armed. If that is not the case anymore this PR can be closed.

[Antiheavy]

Describe problem solved by the proposed pull request
If the user carries the vehicle around the landed flag might be false. Without this change that could result in the EKF initializing the earth magnetic field states and commencing 3D axis mag fusion when still close to the ground.

this is still a problem for those of us who have hand launched vehicles which will be armed and then handled/carried on the ground before launch. although I guess neither this PR or the existing upstream features @dagar linked actually address this issue after the vehicle is armed.... I only mention this here in case anyone has any brilliant ideas how to fix that case as well. thanks.

[CarlOlsson]

this is still a problem for those of us who have hand launched vehicles which will be armed and then handled/carried on the ground before launch.

Oh, that's very bad since in that case it will assume the heading is equivalent to the GPS course over ground to initialize the earth mag states

[Antiheavy]

Oh, that's very bad since in that case it will assume the heading is equivalent to the GPS course over ground to initialize the earth mag states

oh no! @CarlOlsson does this "feature" exist in v1.8.x? or does it have to do with more recent compass changes in Master?

[CarlOlsson]

oh no! @CarlOlsson does this "feature" exist in v1.8.x? or does it have to do with more recent compass changes in Master?

I just checked the logic again and I forgot about one condition, sorry about that. It will only use the GPS course over ground if the velocity is higher than 5 m/s. So that should be fine as long as you don't e.g. launch from a moving boat or something.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. Thank you for your contributions.

[MaEtUgR]

I think we can close this pr because the land detector will not report the vehicle to be not landed when it's not armed:
https://github.com/PX4/Firmware/blob/01b280f7ae1e0b222ed0ea91062392e43b8d2c85/src/modules/land_detector/FixedwingLandDetector.cpp#L62-L65
https://github.com/PX4/Firmware/blob/01b280f7ae1e0b222ed0ea91062392e43b8d2c85/src/modules/land_detector/MulticopterLandDetector.cpp#L131-L133
https://github.com/PX4/Firmware/blob/01b280f7ae1e0b222ed0ea91062392e43b8d2c85/src/modules/land_detector/MulticopterLandDetector.cpp#L173-L176
https://github.com/PX4/Firmware/blob/01b280f7ae1e0b222ed0ea91062392e43b8d2c85/src/modules/land_detector/MulticopterLandDetector.cpp#L216-L219