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Take off from boat - word of warning

Weird indeed. This is one of those cases where the FC made an abrupt change to the Yaw value. At 8.411 secs Yaw abruptly changes from -149° to 41°. But, both the magnetometers and Z axiz gyro don't record that change. Erratic flight then ensued.
View attachment 110280

Why did the FC (erroneously) decide that Yaw was incorrect and needed fixing? Still thinking about this.

Maybe @sar104 has something to add.
Hmm, I am completely lost here. What should I do? Warranty claim?

I don't want to fly the drone anymore if this can happen and it wasn't my fault/magnetic interference that caused the fly away...

But BIG thanks again for trying to help me understand what happened! I was so sure it was magnetic interference.
 
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Hmm, I am completely lost here. What should I do? Warranty claim?

I don't want to fly the drone anymore if this can happen and it wasn't my fault/magnetic interference that caused the fly away...

But BIG thanks again for trying to help me understand what happened! I was so sure it was magnetic interference.
Fair point. You came here for answers - not some inconclusive speculations about the finer points flight control. If it were my MM I would figure it's a one-off. I'm guessing that there were a couple of contributing factors that caused the FC to think Yaw needed to be changed.
 
Fair point. You came here for answers - not some inconclusive speculations about the finer points flight control. If it were my MM I would figure it's a one-off. I'm guessing that there were a couple of contributing factors that caused the FC to think Yaw needed to be changed.
Don't get me wrong. I really appreciate that you guys are trying to figure out what caused the fly away! I thought I knew what the problem was, but you helped me realize it was more complicated than what I assumed.

But how do I relate to this and move on? There is a DJI forum too. Should I post my/your findings there and see if DJI responds? Or should I contact DJI support directly and claim a new drone on warranty?

Thanks again!
//Olof
 
I thought I knew what the problem was, but you helped me realize it was more complicated than what I assumed.
Your case was similar enough to the yaw error situations that are seen often enough.
But there are some differences that are puzzling.

But how do I relate to this and move on? There is a DJI forum too. Should I post my/your findings there and see if DJI responds? Or should I contact DJI support directly and claim a new drone on warranty?
Unfortunately the DJI forum isn't a good place to look for technical help.
You're unlikely to get anyone there as experienced as here.
If the issue was caused by the same factors as all the other yaw error cases, it's not a problem with the drone at all.
Rather it's a problem with the launching environment.
If it's safe for 5 or 6 trial flights over land, it's probably going to be safe into the future.
 
Your case was similar enough to the yaw error situations that are seen often enough.
But there are some differences that are puzzling.


Unfortunately the DJI forum isn't a good place to look for technical help.
You're unlikely to get anyone there as experienced as here.
If the issue was caused by the same factors as all the other yaw error cases, it's not a problem with the drone at all.
Rather it's a problem with the launching environment.
If it's safe for 5 or 6 trial flights over land, it's probably going to be safe into the future.
Ok, thank you for your input. I will try to fly on a nearby soccer field for a few times to see what happens. But I will never try to fly from a boat again with this drone, way too risky! I realize that I was very lucky that I could land the drone in a 'safe' way.

It is only now that I also realize the importance of getting the 'DJI Care Refresh'. Anything can happen even if you think you are careful.
 
At worst, interference might swamp your control signal and initiate RTH, but it will never cause the drone to fly away.

Go to DJI Flight Log Viewer | Phantom Help
Follow the instructions there to upload your flight record from your phone or tablet.
That will give you a detailed report of the flight.
Come back and post a link to the report it gives you.
here is a link to the flight log of that run away flight.
you will notice there is no controller input and no error message as the drone proceeds to flight at almost 40 mph towards a cliff when i regain enough control to bring it back over the water. the start point is nort correct it should be the same as the home point but they are very different for some reason this might have something to do with the fly away. this really didnt answer any questions but rather i have even more questions now.
 
here is a link to the flight log of that run away flight.
you will notice there is no controller input and no error message as the drone proceeds to flight at almost 40 mph towards a cliff when i regain enough control to bring it back over the water. the start point is nort correct it should be the same as the home point but they are very different for some reason this might have something to do with the fly away. this really didnt answer any questions but rather i have even more questions now.
Also the direction the flight log shows the drone facing during the flight is incorrect during the flyaway as well. i will upload the flyaway portion of the video
 
here is a link to the flight log of that run away flight.
Your flight data is scrambled and difficult to read.
It starts with the time showing 10:05.5 minutes, the battery is at 60% and the drone is 78 feet in the air.

But at the 100th line of data, the time jumps back to near the start of the flight at 0:09.3 and no home point recorded at 0:15.5

The home point is at the southern extremity of the flight path.
The flag in the map is at 10:05.5 and the straight line between them was never flown by your drone.

But your description and the curved flight path suggest that your issue was a yaw error situation caused by launching in a bad magnetic environment.
You were lucky to recover the drone.
Most yaw error incidents don't end that well.
 
Your flight data is scrambled and difficult to read.
It starts with the time showing 10:05.5 minutes, the battery is at 60% and the drone is 78 feet in the air.

But at the 100th line of data, the time jumps back to near the start of the flight at 0:09.3 and no home point recorded at 0:15.5

The home point is at the southern extremity of the flight path.
The flag in the map is at 10:05.5 and the straight line between them was never flown by your drone.

But your description and the curved flight path suggest that your issue was a yaw error situation caused by launching in a bad magnetic environment.
You were lucky to recover the drone.
Most yaw error incidents don't end that well.
What does poor magnetic enviroment mean? Do you think it is because of the boat being metal? The trolling motor signal is pretty strong and interfere with the radio and can even cause interference in the fish finder as well. It is wireless and uses gps positioning just like the drone does. Is it possible that it interfered with the drone causing the yaw error? Why wasn’t the yaw error on the flight log? I’m sorry for all the questions I have not been flying drones very long and this is the first problem I have run into.
 
What does poor magnetic enviroment mean? Do you think it is because of the boat being metal?
It means that the compass was deflected by a live electric current or iron or steel that was either large enough or close enough to the compass to have an effect.
Unless the boat was made of steel, that won't have been an issue.

Is it possible that it interfered with the drone causing the yaw error?
Most of those things probably had no effect.
Where was the drone when you powered it up?
What was close to that area?

Why wasn’t the yaw error on the flight log?
It probably is if y\we dug deep enough.
Phantomhelp doesn't show all error messages with Mavic Mini logs.
 
I also had a run away from the boat, I was able to regain some control and managed to steer it away from a cliff and back over the water where I was able to get it to go into RTH mode where I got it close then guided it the rest of the way back to the boat. The motor was not running but the trolling motor was running and operates on a WiFi signal so I was thinking that maybe it provided some interference causing the run away. The drone was hovering behind the boat for a while and there was a little bit of cross wind as well. How do I look at the logs?

I would suggest you to open a seperate thread for your case and post the .DAT file. The .TXT file indicates that the chance of having YAW error is high.
 
It means that the compass was deflected by a live electric current or iron or steel that was either large enough or close enough to the compass to have an effect.
Unless the boat was made of steel, that won't have been an issue.


Most of those things probably had no effect.
Where was the drone when you powered it up?
What was close to that area?


It probably is if y\we dug deep enough.
Phantomhelp doesn't show all error messages with Mavic Mini logs.
The drone was only 25 ft from the boat and well within the range that the wireless controller for the trolling motor operates. That is the only thing i can think of that would have caused any kind of interference with the drone. They both use GPS guided wireless wifi signals to operate. I will see about getting the dat file to see what the exact errors are.
 
The drone was only 25 ft from the boat and well within the range that the wireless controller for the trolling motor operates. That is the only thing i can think of that would have caused any kind of interference with the drone. They both use GPS guided wireless wifi signals to operate. I will see about getting the dat file to see what the exact errors are.
Would definitely like to see the .DAT please. It'll be FLY054.
 
Attached is a .csv that's been fixed. The rows were manually re-ordered to fix the problems described by @Meta4. In addition the IMUCalcs package was applied. Just submit it to CsvView to see the IMUCalcs data.

This is another case where there doesn't seem to be a problem with initial Yaw - not a geomagnetically distorted launch site. This can be seen from the first couple of secs in the video where the bridge is visible and the Yaw value.
1597327056193.png
 

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Attached is a .csv that's been fixed. The rows were manually re-ordered to fix the problems described by @Meta4. In addition the IMUCalcs package was applied. Just submit it to CsvView to see the IMUCalcs data.

This is another case where there doesn't seem to be a problem with initial Yaw - not a geomagnetically distorted launch site. This can be seen from the first couple of secs in the video where the bridge is visible and the Yaw value.
View attachment 110476
I was able to put it into RTH mode so should the flight path represent that as well ?
 
I was able to put it into RTH mode so should the flight path represent that as well ?
The log shows RTH starting at 553 secs. In this situation the RTH isn't going to work as can be seen by the flight path. Basically, the MM has the wrong Yaw value and any attempts to move will be in the wrong direction. The video shows the MM pointing towards the row of trees when it approaches the shore, but the MM thinks it's pointing in the opposite direction.
1597328745449.png
Any chance of getting the .DAT?

And, if you haven't powered up the MM can you retrieve a file from the external SD card that has the video you submitted. The file is MISC/LOG/flylog/fc_log.log. It get's overwritten every time the MM is powered up.
 
The log shows RTH starting at 553 secs. In this situation the RTH isn't going to work as can be seen by the flight path. Basically, the MM has the wrong Yaw value and any attempts to move will be in the wrong direction. The video shows the MM pointing towards the row of trees when it approaches the shore, but the MM thinks it's pointing in the opposite direction.
View attachment 110485
Any chance of getting the .DAT?

And, if you haven't powered up the MM can you retrieve a file from the external SD card that has the video you submitted. The file is MISC/LOG/flylog/fc_log.log. It get's overwritten every time the MM is powered up.
 
Inked1597328745449_LI.jpg
It did eventually go into RTH mode where the yellow arrow is located and returned to the boat where i eventually reclaimed manual control of it. how do i get the DAT file?
 
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