Hello, I have been flying for 5 months or so the old APM 2.8 and firmware Copter 3.2.1 and heard a million times that I need to upgrade, I know that, but while I am still using this:
I want to get the most of the performance I can. I am not very satisfied with the behavior in air, mostly on descent or fast movement, seems like the PIDs are a bit too high, or it’s just how I see it? I am not very good at analyzing them, they don’t contain much information because of the old firmware, but still, look at the ATT tab more closely, Desired vs Actual I mean! And see if the behavior I’m getting is normal, and if not, what should I change? Maybe it will also increase my flight time because the copter will not try to correct itself too much anymore!
You are correct in thinking that improving the tuning will help with battery usage. People assume because it looks OK (visually) in the air that they don’t need to do more tuning. The logs tell the real story, and the better you can get the desired vs actual roll/pitch/yaw then better your aircraft will be able to handle disturbances and different payloads.
You’ve got Motor 4 and 2 going to maximum quite a lot, so there’s a weight distribution problem there. And it’s underpowered too, but fix the centre of gravity and it might be acceptable. Or reduce the take off weight.
The only APM flight controller I had working, although on an octo, had these params different to yours:
RATE_PIT_D,0.01500000
RATE_PIT_I,0.25000000
RATE_PIT_IMAX,500
RATE_PIT_P,0.25000000
RATE_RLL_D,0.01500000
RATE_RLL_I,0.25000000
RATE_RLL_IMAX,500
RATE_RLL_P,0.25000000
RATE_YAW_D,0.00000000
RATE_YAW_I,0.02000000
RATE_YAW_IMAX,800
RATE_YAW_P,0.30000001
You could try them and see if it makes the attitude better or worse.
There’s really not enough info in those old APM logs to tell much more than guessing.