Almost lost my MPP!

[J-Dog]

Yes it was probably not a great idea to fly at this time but I was hovering maybe 20 feet up filming an awesome storm moving in with a really cool shelf cloud. Wind all of the sudden gusted real strong so I started to land it right then. I have no idea what happened but I had no control over anything. It started to fly away and changed its mind I suppose because it slowly moved above my utility trailer just barely out of reach. For some storage reason it decided to descend a few more inches and I jumped up and grabbed it. I was shaking like a leaf! I tried shouting it off by the button but it wouldn't shut off. Motors screaming, I got my hand in there and pushed the battery release buttons and had to wiggle it back and forth, left and right until it finally lost connection to the drone. Omg. Whew. Is there any way someone could tell me what happened? What did I do wrong?
I'm attaching The two flight log associated with this crazy experience. No idea why there are two because it was only one flight hovering about 15-20 feet. View attachment DJIFlightRecord_2019-06-09_[12-46-34].txtView attachment DJIFlightRecord_2019-06-09_[13-05-01].txt

 

[Texas Mavic]

Sure wish I could understand the graphs generated by CsViewer so I could offer solid advice. I have heard of this happening from geo magnetics, sun related Kp index I believe it’s called. Do you have external batteries or all stock birdside set up?

 

[J-Dog]

Its all factory. I've got about 15 hours, 300,000 feet on this beast. Never once had a problem. I know now that the battery was low but I never got a warning. At least I didn't see or hear one. It might have been trying to auto land? My screen said no connection. It all scared the crap out of me. I'm in Florida surrounded by roads, houses and water. I can imagine so many things that could have happened.

 

[runeOfRune]

Upload .DAT log from the phone, there's not much in the .txt. I guess there's two logs because you lost connection? The other log begins already in RTH, it's weird.

Also for future reference, you can just turn the AC upside down to shut the motors off if you hand catch it. This may be a bit difficult though

 

[J-Dog]

I think this is it

 

[J-Dog]

And I didn't even think of turning it upside down. Whoda thunk

 

[sar104]

There was something very wrong with that flight, but I'm not quite sure what. If you compare the IMU velocity record, integrated with respect to time to get position, with the IMU position record and the actual GPS position data, there is serious disagreement:



I suspect that the GPS data (blue) are accurate, but perhaps you can comment on that. There were no compass errors evident:

 

[runeOfRune]

Yo, what is this anyway?

-57.002 : 2353 [L-CFG]can't find var in opentable when read, hash: 0
-57.000 : 2353 [L-CFG]can't find var in opentable when read, hash: 0
-56.999 : 2353 [L-CFG]can't find var in opentable when read, hash: 0
-56.996 : 2353 [L-CFG]can't find var in opentable when read, hash: 0
-56.995 : 2353 [L-CFG]can't find var in opentable when read, hash: 0

Ant then there it goes off the hook:

25.603 : 6410 [L-CTRL]Uncertainty gain adjust FAIL
269.983 : 18221 [L-FMU/LED]action changed. aircraft install warning!:aircraft vibration err(3)
282.382 : 18821 [L-NS] [AHRS] gyro mag inconsist on
289.962 : 19185 [L-NS][AHRS] gyro mag inconsist off
292.822 : 19325 [L-NS] [AHRS] gyro mag inconsist on
610.444 : 34687 [L-FMU/LED]action changed. aircraft install warning!:mass center install err(2)

Try calibrate IMU? Did you do any mods?

 

[J-Dog]

Wow. I don't know how to read all of this but none of it looks good.
I eventually about an hour later, put a fresh battery in it. Everything was fine but I didn't fly any higher than 6'. And only 10' away. Then landed. But no bells whistles or problems. I'm not flying it until I know what's going on.
I appreciate everyone's help.

 

[J-Dog]

It was a huge storm coming in. Maybe there's something to the magnetic interference thing

 

[J-Dog]

Its all factory stuff.

Yo, what is this anyway?


Ant then there it goes off the hook:


Try calibrate IMU? Did you do any mods?

 

[J-Dog]

Well, I've looked at the DAT file, both of the txt files and I can honestly say I just don't know. Are there other files I can snatch off of the flight data that would help figure this out?

 

[Huckleberry]

My initial impression was like yours, wonder if it is something to do with all of the electricity in the storm. I'm no help with reading the files, its all a foreign language to me.

It also made me think that if I ever try to fly in a storm, may be smart to tie a roll of fishing line on to one of the landing gears in case of a run away? Obviously your range and AOA would be very limited by doing so, but if all one was doing is trying to get some elevated shots of a storm moving in then I wouldn't think it would be that big of a deal, just go straight up and don't plan on flying away from home point.

 

[Meta4]

I have heard of this happening from geo magnetics, sun related Kp index I believe it’s called.

You might have heard others suggesting this but you've never heard of it actually happening.
There's never been any drone incident caused by any Kp-index issue.
It's just a popular form myth.

 

[Texas Mavic]

You might have heard others suggesting this but you've never heard of it actually happening.
There's never been any drone incident caused by any Kp-index issue.
It's just a popular form myth.

Seems as if it would be a compass issue, which would resolve itself before it interrupted flight controls. Mythical KP magnetic issues. Agreed.

 

[sar104]

Yo, what is this anyway?

Ant then there it goes off the hook:

Try calibrate IMU? Did you do any mods?

I've no idea what the "can't find var" messages refer to. That may or may not be related to the problem. The "[L-FMU/LED]action changed. aircraft install warning!:mass center install err(2)" does sound like it's complaining about the aircraft CoM - do you have accessories on this aircraft. I've seen the "[L-NS] [AHRS] gyro mag inconsist on" warnings when the gyros and compass disagree, but that didn't happen on this flight.

 

[sar104]

You might have heard others suggesting this but you've never heard of it actually happening.
There's never been any drone incident caused by any Kp-index issue.
It's just a popular form myth.

And it was not a magnetic interference problem, so the sun is definitely off the hook for this one.

 

[J-Dog]

The only thing that's not factory on it is two eyes and a mouth stickers. No mods st all.

 

[sar104]

The only thing that's not factory on it is two eyes and a mouth stickers. No mods st all.

In that case I suggest an IMU calibration, then check the DAT event stream to see if the "var" errors go away and the IMU data are consistent with the GPS data.

 

[J-Dog]

I kinda remember Benjamin Franklin doing something like that!

My initial impression was like yours, wonder if it is something to do with all of the electricity in the storm. I'm no help with reading the files, its all a foreign language to me.

It also made me think that if I ever try to fly in a storm, may be smart to tie a roll of fishing line on to one of the landing gears in case of a run away? Obviously your range and AOA would be very limited by doing so, but if all one was doing is trying to get some elevated shots of a storm moving in then I wouldn't think it would be that big of a deal, just go straight up and don't plan on flying away from home point.