Heading drift issue (with LPE)

I have been experiencing some problems with a fault that seems to appear in my pixracer (firmware 1.8.0).

The symptoms are that the yaw drifts while my quad is in off board position control mode. This is (at least temporarily) resolved by rebooting the FCU so I don’t think the issue relates to the rest of the system (offboard computer streaming from motion capture system).

Flight logs indicate that an estimator watchdog is triggered but I’m not sure how to interpret this message (a question that has been asked a few times in the forum but I didn’t find an answer). the acceleration power spectral density also seems to have a high attenuation compared to logs where the issue in’t present:

log with fault present: https://logs.px4.io/plot_app?log=0c704e21-3fff-4598-998b-de58b728bb55
log without fault present: https://logs.px4.io/plot_app?log=0dcfccf4-0e43-41fb-b9ab-6fbb082388bf

Any suggestions on how to diagnose this issue?

Hi, did you mean you control your vehicle’s position with the yaw information provided by motion capture system?

Hi @Heng_Xie , yes I control with yaw from motion capture (ATT_EXT_HDG_M set to 2).

(I had ruled out motion capture as a problem because 1) resetting flight controller fixes the issue (while leaving mocap on) and 2) /mocap/pose rostopic was being published and the values looked sensible while issue was present 3) because of the estimator watchdog flags - although now I think about it the estimator could be unhappy with the mocap data).