My attempt at autotuning resulted in a crash this morning.
I fiew the quadcopter previously with a 2S battery. It was quite stable but underpowered.
After upgrading to a 3S battery I set the PIDs to what I believe is the default values:
Stabilize P: 4.5
Rate P: 0.15
Rate I: 0.1
Rate D: 0.004
Taking off and switching to Alt Hold went smooth. I then switched to Autotune and nothing happened. I believe this is because I had the throttle still a tad above hover. Closing the throttle down slightly to get it in the hover range started autotuning and on the first or second autotune roll it started oscillating ending in a crash. I was way too slow to recover it.
The way I read the log file, theses values were used for autotune:
Stab P: 4
Rate P: 0.2
Rate D: 0.005
Dataflash log attached. No CoG issues. Props and motors tuned recently, so low vibrations.
My primary question is:
What caused this crash?
My theory is that the motors may now even be slightly overpowered and I guess that an average PID settings may caused it to respond too violently. But I would appreciate if anyone else can confirm that from the log or share their own experiences.
Is there a way to tell autotune to cool things down a bit and use a range of lower PID values?