post mortem help, sudden loss of gps and fly away in atti. video of log

[glitched]

at 7 sec you'll see at the top it goes from 17 and full bars to suddenly no bars and into ATTI, then it starts flying away from me towards some trees with no wind or right stick movement (only left stick down)

luckily it landed a few feet away from obstacles and that it flew away from the river and not toward.

Still not sure what really caused this. I've done a handful of flights from this location with no other issues.

 

[geigy]

I had something like this - sudden loss of GPS, ATTI mode, drifting with the wind. I used the sticks for about 30 seconds until GPS came back again. It seemed to me for a few seconds that the sticks did not respond, but I have my doubts about that. DJI looked at the logs and suggested that I send my new Mavic back to them.

I removed a Loc8Tor transponder tag that I had stuck to the back of the Mavic (on the angled back of the Mavic, over the DJI logo) that was probably causing interference or blocking the GPS signal, and stuck it on one of the legs. I haven't seen that problem again.

 

[lekrantz]

What firmware do you use?? I have my first issue with the new .600 update. Loss of GPS but I can fly it in ATTI. Did you do a compass calibration and a IMU calibration after your last update?

 

[sekine12]

That looks like it was drifting on the wind. You say there was no wind, but you provided no pitch/roll input to counteract its movement and it really just looks like drifting on a light breeze. Remember, walking speed is about 2mph, which is what most people would call "no wind". Even 5mph doesn't feel like much breeze, but it's 7 feet per second. You can move really, really far, really fast, on not much breeze at all. If you've never flown in ATTI or with an atti-only quad you'd be really surprised how fast you drift.

 

[glitched]

What firmware do you use?? I have my first issue with the new .600 update. Loss of GPS but I can fly it in ATTI. Did you do a compass calibration and a IMU calibration after your last update?

Latest firmware. No calibrations.

 

[glitched]

That looks like it was drifting on the wind. You say there was no wind, but you provided no pitch/roll input to counteract its movement and it really just looks like drifting on a light breeze. Remember, walking speed is about 2mph, which is what most people would call "no wind". Even 5mph doesn't feel like much breeze, but it's 7 feet per second. You can move really, really far, really fast, on not much breeze at all. If you've never flown in ATTI or with an atti-only quad you'd be really surprised how fast you drift.

It sure felt like it was moving faster than what mph readout shows on the log... but there was some slight panic lol. I did not provide any pitch roll input as it was already flying away from the river/water areas towards a small dirt berm and gaurd rail. I would rather have it crash into that than the water! i just concentrated on trying to lower the altitude as much as i can and move the camera/gimbal away from the potential crash direction.

No i have not flown in ATTI in any breeze, i will have to give that a shot in open area. But as far as how much wind there was. All i have to show for that is the tree branches not moving (tall weeds moving from river current) in this short clip:

 

[erkme73]

Pull the DAT off of your bird within the next few flights (as the oldest will get overwritten). Upload it to Dropbox or Google Drive and provide a link here. The resident experts will analyze it and try to figure out what caused the ATTI switch.

Any comments before that DAT file is inspected will be purely speculation...

 

[lekrantz]

Latest firmware. No calibrations.

Try to do the calibration. The first two flights I had after the last update I had the compass error. I did the calibration ritual and after that three new flights and no issues. [emoji108]

 

[sekine12]

Also very possible that your IMU calibration was off by a bit, then either GPS interference or an IMU/GPS disagreement provoked the switch to ATTI. If the IMU's reading of gravity was off just a touch it could easily accelerate away from you.

 

[glitched]

Pull the DAT off of your bird within the next few flights (as the oldest will get overwritten). Upload it to Dropbox or Google Drive and provide a link here. The resident experts will analyze it and try to figure out what caused the ATTI switch.

Any comments before that DAT file is inspected will be purely speculation...

Doesnt the log viewer in the app that i recorded not show everything logged? I pulled the dats from that evening, but there are 8 files from around that time and i dont know which is which. When i try to open them in the dji viewer, nothing really shows up.

 

[RangerEd]

The GPS display doesn't make sense. The GPS count is still updating while the signal indicator is showing no signal. That tells me the GPS receiver is working fine; it's the processing of the signal or data that appears to be the problem.