Strong roll oscillation in Auto mode

ArduCopter Copter 4.0
1

Hi everyone,

I have a problem with my copter in Auto mission mode. It is an Octoquad H configuration. The copter flew well in manual control modes (Stabilize, Altitude Hold, Loiter). However, when I switched to Auto mode to run a mission, I observed a very strong oscillation in Roll axis while the copter was following the planned path, but I’m not sure what was the reason for it. There wasn’t a strong wind during this flight.

Here is the log file: https://drive.google.com/file/d/1Q252_xANIbvWAr_o_tLuH-nxnQ8QKpUF/view?usp=sharing

Could you please give me some suggestions about how can I fix this oscillation problem?

Thanks alot!

2

You can easily see what you are describing in the log. Oscillation in Roll, the Roll Rate output and subsequently in the RC outputs.

Roll
Roll3342×1002 291 KB

Rate Roll
Rate Roll3346×991 302 KB

RC out
RC out1920×574 176 KB

1st set these based on MOT_THST_HOVER as per the tuning guide Tuning
PSC_ACCZ_I
PSC_ACCZ_P
Set this to 10Hz: INS_ACCEL_FILTER

You should definitely configure the Dynamic Notch filter. Start by setting this to 1 (INS_LOG_BAT_MASK) and make a short AltHold hover flight to capture the data. Post that log if you like.

1 Like
3

Hi @dkemxr, thank you for your feedback. I will make this changes and fly again in the next days. Do you think I need to do PID tunning more? I didn’t do the autotune because it is too dangerous for big copter, I tuned it manually. Do you think I need to make some changes in PID as well?

Thanks a lot! I look forward to your response.