Pitch axis Oscillation in auto mode, big copter

Hi, I have a problem in auto mode with a quadcopter, flight well at started but a little oscilations begin after a few waypoints. It flight well in stabilize and Althold, in Loiter mode isn´t perfect, the wind affect a little its altitude and position, autotune already did it.

The follow things was proved:

  • Change EK2_ALT_SOURCE to 2, and EK2_ALT_M_NSE to 6, this improved the AltHold Mode.

  • reduce LOIT_JERK from 1000 to 500, and LOIT_MAXA from 200 to 100. It seems works, a little. but I don´t want reduce more because is out of limits.

  • Reduce ATC_ACCEL_P_MAX from 4000 to 3000, no change noted.

  • Limit ANGLE_MAX to 25. no change noted.

  • Also change the PID values of Pitch axis to same in Roll, the picture shows the original PIDs after autotune.

The oscilation it can noted in the follow image, the bin file is also attached. This logs is from 3 days of test.


The quadcopter hardware:

  1. motors U8 pro 135Kv.
  2. ESC Turnigy 120A.
  3. Battery 16000mAh 6S x 2, 12S serial conection.
  4. 22x6.4 T-motor propellers.
  5. Frame 1200mm
  6. Total weight is 9.5Kg with Gimbal (tuned and powered).
  7. Pixhawk with RDF900 telemetry (issues with telemetry too, but it’s other history).


I don’t have a chance to open your logs right now, but your setup is quite similar to my current one in terms of size (24x7.9, 14kg TOW, 135KV). The one thing I notice is that you have a fairly low Filter setting of 5Hz only on Roll/Pitch axis - is that intentional? I found for my setup that 10Hz works better - have you tried that?

Also your throttle accel parameters seem to diverge from the recommended 2:1 ratio - is that intentional? might not be related to your issue, just noticed it…


Hi Christian, thanks for your reply. The filter configuration is intentional, when i tried to use 10Hz it caused vibrations increment. I’ll check the throttle accel parameters just in case.