already with my last copter I observed high descent rates on fast movements. I thought it was a little bit underpowered.
But now my current copter is kind of overpowered (in stabilize mode it reaches 25-30m climb rate) and the issue remains.
Once the angle goes over aprox. 25-30 degrees, it descents continuously and is only recoverable by increasing the thrust.
As far as I know, the ALTHOLD-algorithm should maintain the height in these modes and automaticly adjust the thrust.
Sounds it like a sensor issue, a parameter issue, or is it just a known issue?
This has nothing to do with power and everything to do with the way the barometer on the Pixhawk acts when moving at a rapid rate laterally. It creates a bit of a low pressure area around the FC which tricks it into thinking it’s ascending a little bit when it actually isn’t. There are probably several topics that allude to this.
I don’t know if this will help you but this workaround is working on my qav210 and robocat frame. I surrounded the pixhawk with packing foam that I got from shipment sent by banggood.com. Before trying this out I messed with different foam cover directly on the barometer but still has the issue with fast forward flight. Since I can’t use a dome I just thought of surrounding the pixhawk with something to keep wind from hitting the fc.