Weird log after manual PID tuning

ArduCopter Copter 4.0
1

We have a quad that can’t flight stable in althold mode. Here is my log file:
https://drive.google.com/file/d/1tzUtCxl5-J6R9Pcnkds3n-8iB3tuDh44/view?usp=sharing
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image1634×865 13.1 KB

I guess the problem is with rate controller d gain. But I’m really amateur at this pid thing. Thanks for all help

2

With RC outputs oscillating this badly it would not fly well in any mode for long.

RCout
RCout3319×1011 312 KB

I would suggest starting over at default parameters + Initial Setup parameters. These are too low:
ATC_ANG_PIT_P,3
ATC_ANG_RLL_P,3
D term is likely too high.
P&I may be too high.
The Dynamic Notch Filter is not configured.

So from default set the Rate Pitch and Roll P&I terms to something like .1 leave D as default. Set these as per the Tuning guide based on MOT_THST_HOVER:
PSC_ACCZ_I
PSC_ACCZ_P
Configure to collect data for the Notch Filter and make a hover flight in AltHold and check for output and rate oscillation. If present lower the Rate P&I values more and try again. When the oscillation is gone configure the Notch Filter and run Auto Tune.

3

Everything Dave says is perfectly true. There’s a lot to unpack in those statements though, so read through the docs and tuning guides very closely.
Make adjustments to fix one issue at a time, do a test flight and check logs to see if you made it better or worse.
Ask more questions here :slight_smile:

Oh, and better describe your aircraft: motors, props, ESCs, frame, battery…

1 Like
4

Thanks for answers. I have 10x45 props, t-motor 2814 1200kv and 4 cell lipo battery. So I alredy read the docs but I really can’t understand how to configure notch filter. Is there a video or an other doc about it?

5

Ok for Harmonic Notch filter there’s plenty of docs and examples in the forum, but here’s the condensed form, assuming you dont have ESC/BLHELI telemetry:

HNOTCH phase 1
INS_LOG_BAT_MASK,1
INS_LOG_BAT_OPT,0

  • hover test >1 minute, check FFT

HNOTCH phase 2
INS_HNTCH_ENABLE,1 ← set this then refresh params to see the rest
INS_HNTCH_MODE,1
INS_HNTCH_REF, hover_thrust
INS_HNTCH_FREQ, peak freq from FFT
INS_HNTCH_BW, peak_freq / 2
INS_HNTCH_ATT,40
INS_LOG_BAT_MASK,1
INS_LOG_BAT_OPT,2

  • hover & dynamic test >1 minute, check FFT results

HNOTCH phase 3
INS_LOG_BAT_MASK,0
INS_LOG_BAT_OPT,0

  • no extra logging, assumes HNOTCH is working great
6

Thank you so much!!!

7

Comprehensive documentation about it
Dynamic Notch Filter