Missions going into Failure mode - why?

🧪 Flight Testing & Log Analysis
1

The hexacopter I fly has completed many missions using PX4 v1.8.2 and earlier. After updating it to 1.9.2 it has experienced problems. The flight in this log looses x, y, and z position set-points just before the failure. Why is this happening? Is the Pixhawk 1 unable to keep up with v1.9.2??? What could be happening to stop the mission? This type of failure occurred in 4 out of 5 missions.

https://review.px4.io/plot_app?log=07a3fe9f-dfd6-43c5-a9cd-7d1c8b3b67fa

In addition, could use some help understanding the following errors:

  • [mc_pos_control] Position-Control-Setpoint-Update-Failed
  • [load_mon] gps low on stack (260 bytes left)
  • [gps] ubx msg: txbuf alloc

Thanks for any help that’s offered.
Joe

2

Some updates and more questions:

  • Looking at the flight logs, we see that failsafe starts at time 6:04. A few seconds before that the ekf2_innovations/vel_pos_inniv.xx parameters stop. What would cause this to happen?
  • Another error message occurs several times – “[gps] ubx msg: More than 100 frame errors, UART Rx was disabled”. What effect does this have?
  • Does the “gps low on stack” warning mean there is a memory issue? Why does it occur?

We keep looking at the logs hoping to find some causes, but our knowledge of the inner workings of the firmware is not that deep, so we need some help to figure out whats happening.

Also, might there be a hardware issue lurking in the dark? Any thoughts about what kind of hardware failure could cause missions to abort?

Thanks again,
Joe