EKF2 IMU0 yaw aligned to GPS velocity - or something else entirely?

ArduPlane Plane 4.0
1

A few days ago, I had a crash in AUTO flight mode that was preceeded by the message from my Pixhawk “EKF2 IMU0 yaw aligned to GPS velocity”.
Before that, everything went smoothly, after that the plane went crazy and spiraled into the ground. What may have caused this? Why would Arduplane 4.05 react so radical to this “alignment”? At about the same time I have aileron going full right. (I have throttle on RC1, RC2 and RC3 are the elevons) . Or am I misreading the logs? Kinda weird is that there is a spike in RCIN/C2 initiating the spiral. I cannot explain where that came from because the plane was on AUTO. It was later switched to RTL by my companion computer but I am at a loss. What can I do to prevent this on future flights?
DF Log is here: DF-Log

EKF2 IMU0 yaw aligned to GPS velocity
EKF2 IMU0 yaw aligned to GPS velocity736×416 322 KB
Look at the stick position in the bottom center. That is RCOUT

2

I have the same problem, in Pixhawk 4 and Pixhawk 4 Mini, I wrote to Hollybro and they told me to upload the Firmaware manually, never directly from Mission Planner, the problem the multirotor with following versions is over, but the same problem continues in Plane. I have tried to disconnect different imu and find no solution. Whit PX4 firmaware its works perfect.

3

Hi Kanord, how am I to upload the firmware manually without MP or QGroundControl?

4

This is they told me about that:
-First, please make sure you have manually dowloaded the firmware file in the correct target category. Please don’t update the firmware directly with missionplanner, do it manually.

Im not sure if its going to be the solution. Today mi problem is “EKF2 YAW inconsitent by “x” degres”, only in plane, but not in copter.
There is atopic about that, may the solution is in that way.

5

i had exact same event on arduplane 4.0.7. flying in FBWA mode with Autotune active. on matek h743 wing.

luckily i managed to recover. then next 4 secs plane was vibrating as if elevator was twitching,
then things stabilized and i manged to land fine

examined the logs. i saw all rudder, aileron and elevator servos outputs forced to MIN values few moments before the error showed and they stayed there for a while. this corresponds exactly to left tilt and nose down experience. video and logs available if anyone wants

log:

https://drive.google.com/file/d/1QzVmgYlvNoC1JoupDZuVZrzvjR7zgndi/view?usp=sharing

6

Same here with my Tarot 680 Pro crashed. Anyone got exact cause for this?

7

not sure if anyone of the team is monitoring this thread