Random YAW issues on flight

We are working on Y6 hexa copter setup and it is always better to have more eyes looking logs.

There are noise especially on Z-axis that we are trying to find. This extra noise seems to cause around 90 degree yaws on a random direction.


UAV is around 12kg in total, Cube orange on spektreworks carrier running PX4 1.13. Original settings are done with the autotune.

This UAV has MC_YAW_P, 5.600383758544922 while few other have MC_YAW_P below 5. Parameter reference says MC_YAW_P should be between 0 and 5.0, is 5 absolute maximum?

Accel 2 especially seems to have rather high vibrations compared to Acc 0 or 1. Is there a easy way to temporary disable accels in PX4?

Yaw issue only appears in mission mode, if on RTL or manual modes, no yawing has been seen.

I’ve only had a brief skim through your logs, so I can’t give much of an answer, but one thing I’d say is that you can (and should) disable Acc2.
On the cube orange, Acc2 is hardmounted (hence the increased vibration) whereas Acc0 and Acc1 are isolated within foam, so disabling Acc2 (or at the very least setting it to lowest priority) is a good idea anyway.
You can do this by setting the CAL_ACC2_PRIO to disabled (0).

There also seems to be some fairly notable deviations between the estimated and setpoint pitch/roll, not just yaw which is worth taking into account.

If I get the chance, I’ll take a look at the log file more closely and let you know if I can work anything out regarding the random and unstable yawing!

@DPatrick yeah I just found that CAL_ACC2_PRIO setting and we will disable acc2 as it is clearly causing some issues. On latest flight we then again did not have major issues even acc2 was clipping. More tuning and problem solving ahead.