P4: gimbal went crazy during the flight

[PeteM]

Suddenly in the middle of a waypoint flight with Litchi, I noticed an initial "jolt" and a few seconds later the gimbal lost all control and began to tilt randomly following the force of the flight. On the tablet screen I noticed "Hardware Error". Upon landing, the gimbal was locked in an unnatural position.

I turned the drone off and on again and the gimbal worked perfectly again. There were no anomalies on the next flight.

What happened ? The wind was totally absent. However, there were some small birds around but no signs of collision on the drone.

 

[WV. Rootman]

Check the flight records. "Phantom help" will tell you how to do it.

 

[RotorWash_UAV]

Suddenly in the middle of a waypoint flight with Litchi, I noticed an initial "jolt" and a few seconds later the gimbal lost all control and began to tilt randomly following the force of the flight. On the tablet screen I noticed "Hardware Error". Upon landing, the gimbal was locked in an unnatural position.

I turned the drone off and on again and the gimbal worked perfectly again. There were no anomalies on the next flight.

What happened ? The wind was totally absent. However, there were some small birds around but no signs of collision on the drone.

Sounds possible that you got tagged by something but I'll throw this in for consideration. I've had this happen 3 or 4 times over the past few months (manual flight w/ GO4). Restarting the bird always sets the gimbal back to normal. Calibration after each occurrence has no effect. Looking through my logs, the error "Gimbal Roll Reached Movement Limit" can be found. On two logs, I noticed the AC was slowing down rapidly when it happened, so I suspect it's a combo of wind/gimbal angle/(de)acceleration that pushes it to the limit and makes it tap out on occasion. I've seen videos of others where their gimbal recovers in flight but that hasn't been my experience. Not a biggie for my current use but if you're looking at the screen when it happens, it's good for a jolt!

 

[PeteM]

Check the flight records. "Phantom help" will tell you how to do it.

Looking through my logs, the error "Gimbal Roll Reached Movement Limit" can be found.

Just downloaded (and opened) both the .dat file from the drone and the .csv file from the tablet.

Where and what exactly should I look for in all those parameters and values ?


On Youtube I also found this video. Very similar to what happened to me. But the gimbal remained "stucked" until the next take-off.

 

[RotorWash_UAV]

Just downloaded (and opened) both the .dat file from the drone and the .csv file from the tablet.

Where and what exactly should I look for in all those parameters and values ?

The error I mentioned was found by uploading my GO 4 txt log file (same for Litchi .csv) to one of these sites:

PhantomHelp Log Viewer

AirData Log Viewer

The AC's .dat file may show indications of a mid-air contact if one happened but I'm not familiar enough with CsvView/Datcon to further advise.

Here's what it looked like for me after the said error happened.

 

[PeteM]

The error I mentioned was found by uploading my GO 4 txt log file (same for Litchi .csv) to one of these sites:

PhantomHelp Log Viewer
View attachment 121782

AirData Log Viewer
View attachment 121783

If I analyze the .csv file with these two methods no error message or anomaly appear.

I also decrypted the .dat file and I end up with an excel spreadsheet full of parameters and values. Can anyone help me figure out which column to check to understand if the gimbal had a problem or if there was a mid-air collision ?

P.S.
The video is private.

 

[RotorWash_UAV]

There's also a possibility that Litchi didn't record the error to the log. Litchi makes two logs, a .csv and a .txt file, might be worth checking the other file just to be thorough. Under iOS the Litchi txt logs are located in the Litchi » Documents » SDK_logs » FlightRecord folder. With Droids it's located in the DJI » com.aryuthere.visionplus » FlightRecord folder.

Thanks for the heads up on the video, forgot to switch it over to unlisted, now fixed.

 

[AWD]

Last year I had the gimble go nuts during a flight. Locked up good at an odd angle. Happened twice in one month.

Haven't seen it since. P4 flew normally during both episodes.

Still haven't figured out a reason and haven't seen it this year at all.

AD

 

[PeteM]

With Droids it's located in the DJI » com.aryuthere.visionplus » FlightRecord folder.

I've downloaded the file "DJIFlightRecord_2021-XX-XX_[XX-XX-XX]" from the tablet.

The file is almost 3 Mb but is encrypted and no reader can convert it into something readable. How can I do ?

 

[RotorWash_UAV]

I've downloaded the file "DJIFlightRecord_2021-XX-XX_[XX-XX-XX]" from the tablet.

The file is almost 3 Mb but is encrypted and no reader can convert it into something readable. How can I do ?

The logs from that folder should have a .txt extension and be readable once uploaded to PhantomHelp or AirData. If neither site can read it then it could be corrupted for some reason, maybe try copying it over again from the tablet.