Backup IMU Warning – Can that happen once?

[calmar81]

On my last flight yesterday (the drone was maybe 20m above me when that happened) I had a short disconnect, which unfortunately is not displayed on the flight recordings in the DJI Go 4 app when the flight is being played back.

But what I do see is a few warnings that I'm not sure about because I've never had them. The question I have with you: Can this happen once (okay... it happened twice – flight time 6:46 and 7:15) or is it a sign of something worse?


English translation:
redundant sensor change: navigation system
switched to backup-imu


English translation:
upward obstacle detection


English translation:
redundant sensor change: navigation system
switched to backup-imu

In the next 2 weeks I have some small "paid gigs" but with longer flight times and distances with the drone, which should then work reliably. Many thanks in advance for your answers and assessments!

 

[Former Member]

The first questions I would ask are if it has been in a crash? If no crash, have you been flying in the fog or wet conditions?

Just as a precaution, I would calibrate the IMU in DJI Go 4. I would also calibrate the vision sensors in DJI Assistant 2. .

 

[calmar81]

There was no crash... also landed normally and was controllable as usual. Maybe there was a small sudden movement of the drone on the second event... but I only heard a very quick higher pitch of one or more motors.

It wasn’t wet or foggy at all... beautiful sunshine and no wind.

 

[loop3]

Did you ever find out what trigerred those errors?

In my last 4 flights I had the same errors every time, at various intervals of time. Each time the recording gets stopped and the resulting video is corrupted and unplayable.

 

[dtp]

I had the same issue although for me I only received the errors when flying in temperatures below 3C.

DJI repaired the aircraft free of charge.

 

[Deleted member 94047]

The Mavic 2 has two IMUs, but my understanding is that only one of the two is used by the FC at a time. As such, it is possible that the FC switched from one to the other mid flight for some reason. Would be interesting to see the flight logs (both txt and DAT files) for the flight in question if you can upload them.

 

[loop3]

After an IMU calibration, on a flat surface, a calibration of all cameras from the Assistant 2 software and a firmware refresh, I managed to get rid of the IMU backup error.

On my last two flights, I recorded 20 mins video without any problems.

I strongly recommend these steps to everyone having these issues.