@MagicRuB & @tridge
Thanks for offering to help look into this issue. I've started this new thread as requested. Sorry about the extra posts in the release thread!
As mentioned I'm facing an issue with my aircraft (My Twin Dream) with pixhawk FC with Arduplane 3.7
It usually only occurs in cruise mode and it seems to depend what throttle position I have (or what demanded airspeed I have, since throttle nudge is on) If I change the throttle up and down enough I eventually can get a spot where the throttle and pitch respond as predicted but otherwise the throttle surges up and down very quickly:
7.5 minute mark: https://www.dropbox.com/s/4vs6tvkrr7h8gb1/8.BIN?dl=0
17.5 minute mark: https://www.dropbox.com/s/hw6y8csr3jmkib8/7.BIN?dl=0
It seems to be TECS related as it presents as an oscillation on the pitch and the throttle (height/speed control?).
I have tried re-flashing and re-tuning numerous times both manually and using auto tune as the basis. I have changed all hardware on the plane with the exception of the ESCs and the Pixhawk itself. Maybe I just have something in the tune wrong?
I have also tried adjusting throttle slew (various settings down to 10%) and TECS time constant (up to 7.0) with no difference in terms of the error.
Massive thanks for any help anyone can offer