Throttle completely unresponsive in AltHold after VIO divergence

Hi everyone,

I did a test flight today using VIO (Visual Inertial Odometry) on my drone and encountered a complex issue. I am hoping someone can help me understand what went wrong.

Here is the timeline of the event:

  • VIO Divergence: At exactly 458 seconds into the flight, the VIO clearly began to diverge.

  • Emergency Action: Seeing the divergence, I immediately switched the flight mode to AltHold. I then manually disabled the VIO node to stop it from publishing visual odometry messages to the flight controller.

  • Throttle Issue: Once in AltHold with the VIO node disabled, the drone completely stopped responding to my throttle inputs.

  • Rangefinder Glitch: I should also mention that I am running a ToF (Time of Flight) rangefinder. For some reason, the ToF data became stuck at exactly 2 meters. However, according to the logs, this frozen rangefinder data was still being fused by the EKF.

My questions:

  1. Has anyone experienced a loss of throttle control in AltHold after killing a VIO node mid-flight?

  2. Could the EKF be ignoring my throttle inputs because it is fusing the stuck (2m) ToF data, thinking the drone is maintaining a perfect altitude?

  3. did the div at at vio system can change the hte value and change my thurttle value

Any advice on how to debug this not stable altitude hold situation ?

hi did some one face the same problem ?