Loss of control

[m00se]

So yesterday I made about 15 flights, totaling over 50gb of video taken,

I have only three complaints,
1) the zip broke on the case during transport
2) more seriously, at one point I lost control during about 2 seconds, every command I gave resulted in the drone flying backwards with the wind, it was just after a fast decent from 80m to 2m flying forward through a goalpost. It must have been a signal error because I was behind me when it happened, I pointed the antennas on the RC at it directly and regained control,

3) also quite serious, after taking about 10 snapshots in short sucession the app froze up and disconnected, I still had RC control during the time, and about 15 seconds later the app connected again on its own,

any ideas on points 2 and 3?

 

[Kilrah]

2) is likely the loss of compass. Switch to ATTI manually to regain control quicker.$
3) could be a mobile device hiccup.

 

[m00se]

The app said nothing about a compass failure, whereas on previous occasions I have seen it pop up,
I will bear it in mind though for if it happens again.
I did notice that when up at 80m it didnt fly in particularly straight lines, and the gimbal had a few degrees offset to the body of the drone

 

[Kilrah]

From my experience on the only flight I had the issue on and a bit of extrapolation the sequence goes that way:
- In GPS mode compass data or GPS becomes degraded, but the FC still believes in it. This causes a flyaway situation as the FC will be doing the wrong actions to try and maintain control. Whatever your inputs are they do nothing as they are "ground path" commands, and the FC isn't able to have its location under control at this point.
- The FC decides the data is invalid and switches to ATTI. You regain control and the warning pops up.

There can be a varying amount of time between those 2 events, so you can be in the flyaway state for several seconds until either:
- The FC decides the data is really bad, switches to ATTI and you get the warning
- Data quality returns to normal before the FC switches, and you get no warning.

Switching manually to ATTI gets you out of that temporary state and back in control right away.

I have read hundreds of ATTI dropout and "flyaway" posts but absolutely none that seemed to describe this behavior properly. I was flying FPV with HDMI OSD, which made it very obvious what the aircraft behavior / GPS signal indicator / flight mode indicator sequence of events was so I'm pretty sure of myself, also it would explain the different experiences I've read about (the key between them is the time the FC stays in the uncontrolled state before switching to ATTI). It also suggests the opposite of what everybody says the issue is (FC should not drop to ATTI that easily), because the dangerous condition is precisely between the moment it gets bad data and the one it switches to ATTI.
My take is that the issue is higher in the chain i.e. in the fact that data goes bad in the first place, not in how to handle the case where it is bad.

Unfortunately we'll never know the details of the fixes DJI has done for the next firmware.

That flight was actually the one I made to have logs to submit to DJI for the beta testing application, and I have included these whole comments but of course no answer, neither about the problem nor about the beta application actually, but the latter seems to be because they only retained those who had done the whole process by Mar. 31 while I sent my log on the 1st due to work getting in the way. Oh well, their loss of a motivated and qualified tester who knows what he's talking about...

Note: My I1 had about 7h30 of flight without any prior occurrence of the problem. I created the problem by purposefully not calibrating the compass after moving 300km from the previous flying location (compass mod was about 1650). When the issue started showing up it was about 2mins in on the 2nd flight of the day, and I continued flying for about 3 minutes with the problem to get a feeling for it (during which I had maybe 5-7 events complete with gimbal twitch), landed, did a compass cal (without powering off), and took off again (compass mod now about 1300). The rest of the battery (about 6mins) was uneventful.

 

[m00se]

I would generally agree with that from the two glitchy flights i have had so far,

there seems to be a time where the FC doesnt know the data is bad, on the first flight I got a message in the app,
on this one it recovered before that point.

I think ATTI should be the lower most position of the switch, especially with a low profile switch, I find it hard to accurately switch to the middle position,
If atti were at the bottom, especially in a panic situation, it would be easier to select

 

[jaisonp]

What is the best suggestion to fly I1 to protect your aircraft? And why GPS position sometime is scary? Thanks


Sent from my iPhone using Tapatalk

 

[worldsoutro]

This happened to me twice yesterday and I was prepared for it after reading so much on this forum but it still made my heart beat..... I am thinking about waiting until the FW is out until I fly again.

 

[m00se]

I flew so much over the weekend that I have 150gb of 1080p video, It only happened once and I had one GPS dropout in an area that was obviously going to have it,

I have gotten veyr used to flying it and somewhat trust it.
I will say that the GPS hold isnt always great, but its ok,

It threw a message of "MC data error" at me,so i grounded it thinking "**** how am i guna check on this without google"? then I remembered I have kilrah on my phone, So he helped me out with that and I flew again.

I had a mag calibration error on the floor where I had to takeoff from, due to scafolding holding me 20m in the air, so I moved it a bit until that went away

I will say though that in a real life situation with other signals around, the video has a hard time being usable, I had about 1second delay the whole time even when manually chosing a channel and setting the lowest quality video rate