Improve climb-out logic for RTH. Different margin for airplane and copter

[digitalentity]

New altitude margin logic for climb-out:

Airplane: 10% of target altitude but no less than 1m
Copters: 5% of target altitude but no less than 50cm

[oleost]

Test flown on airplane. Seemed okey, will have to verify with logs later.

Did only test regular RTH as the weather was extremely windy and no condition to do any more flying.

[oleost]

@digitalentity Not sure it works as intended?

https://drive.google.com/open?id=0B-yHzNtOXxbETG0xdl9RTEFybDA

I watched video, seems like it stops climbing the same time it turns?

The log is 3/3 where I fly.

[stronnag]

Flight tested. No regression on multi-rotor.

[digitalentity]

@oleost it indeed keeps climbing during and after the turn, however last meters are tricky - we don't have proper tune - need Position Z I-gain to be able to compensate for sustained errors.

[oleost]

Okey, then it's probably okey to merge in? Or do you need some more testing?

Yes last meters are tricky, that most of the reason for this wanted feature, is it doesn't need the last meters before turning home.

[digitalentity]

Merged. Still, issue of better tune for AltHold PIDs on airplane persists...

[oleost]

I can try 'nav_fw_pos_z_i' next time.

Got any idea where to start?

5, 20 or 100?

[digitalentity]

@oleost unfortunately I have no idea. Try with relatively small value first.