I have a Pixhawk with ArduPlane 3.2.3 on it that crashed. This combination of parameters and firmware has several hundred hours on it and in air crashes are rare ( sadly bad launches and landings are more common than I would like but they are user error and that's life). I started looking through the logs and it appears as though EKF is frozen. EKF1 shows .-.02 roll and -4.43 pitch for the whole log.
What can cause the EKF code to freeze like this ?
I know the DCM code runs in parallel and is a fall back if EKF has problems but in this log the EKF values never change.
I tested it on the ground and the EKF values in the new log are exactly the same as from the log where it crashed. EKF1 still shows .-.02 roll and -4.43 pitch for the whole log.
As for the crash it looks like it freaked out right after the takeoff command completed. Something caused it to get crazy roll inputs and I have found that ardupilot does a poor job with flying wings once they are rolled over too far. Instead of rolling level and then dealing with pitch, its pitch to roll compensation pulls the nose up while rolled over and ends up making it worse.
Any thoughts ? Bad pixhawk? Known bug ?
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