My Mini Talon went down and crashed soon after the takeoff. I lost total control right after EKF3 active and EKF3 yaw alignment message. Everything went haywire after the EKF3 initialization. Plane is write-off
Home arrow started pointing to total wrong direction and on the log viewer, plane started flying sideways right after EKF3 alignment. All arming checks were in place. Not sure what happened with EKF3?
Arduplane 4.4 Dev from a custom firmware server with selected options for KakuteF7.
Here is the log:
Just before EKF3 Alignment:
Right after EKF3 Alignment
March 15, 2023, 8:55pm
This was a failure of the GSF yaw estimator, which is used by EKF3 when there is no compass.
I’ve opened an issue for this, and raised it with @Paul_Riseborough in our discord EKF channel:
08:43PM - 15 Mar 23 UTC
The GSF yaw estimator can sometimes produce a very bad yaw. This particularly af
… fects fixed wing aircraft with no compass. EKF3 initialises after launch using GSF and can result in the EKF getting bad roll/pitch estimates.
This issue is to collect examples and work on a fix
Ideally we would get an example with replay logging enabled to be able to analyse properly. That requires LOG_DISARMED=1 and LOG_REPLAY=1
- https://discuss.ardupilot.org/t/ekf3-yaw-alignment-on-v4-4-dev-brought-my-plane-down/98076 log http://uav.tridgell.net/GSF-failures/00000071.BIN
- use the old GPS alignment method for fixed wing with no compass
- before activating EKF3 (over DCM) check for low velocity innovations for N seconds
we’ll look into ways to prevent this happening again. Really sorry this caused a bad crash
Thanks Henry and Tridge for looking into. Glad the issue was found.