slow sinking after engaging Pos Hold

[chschmid]

I still see a slow drop in altitude after engaging POS Hold. According to the PID videos I changed NAV_ATL_SPED_I from 2.85 to 2.9 but could not see a difference.
Any hints are appreciated.



Thanks

Christof

[plexus]

That is coming from your hover , it is too low; To adjust see that post:
viewtopic.php?f=27&t=539&start=10

That is to adjust the Factor throttle in the QGC.

[chschmid]

I am not positive about that. When hovering in manual my values are ok.

It is more that when POS Hold is engaged, the quad sinks very slow unless I apply some throttle. The moment of transition is fine, no noticable RPM change.

After a while, altitude seems to bee stable. But still rather sinking.

Best
Christof

[plexus]

Yes it seems to be good, indeed.
On my side the point of hold position is a little bit higher (750). But i have also an instability. Sometimes is correct . See my video in the other post:
http://www.youtube.com/watch?v=d7PPE2of ... e=youtu.be

And when you are in hold and you switch to manual, it goes down ? If yes, I think your value is not correct.

[chschmid]

I did not pay attention to that, but I usualy apply some throttle before switching back to manual.
It would be interesting to see your logs of your flight, especially when you come back to the pole.

Any ideas how to overcome the slow sinking?

[bn999]

Increase your NAV_ATL_SPED_IM & NAV_ATL_SPED_OM parameters. You are probably not allowing enough throttle authority to the NAV controller.

[chschmid]

Thanks Bill, I will try that.

[chschmid]

I was setting IM and OM to 660. The result was good, sinking eliminated.