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Compass error, Yaw error, IMU error and so on.

Jnse

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Hi
When i fly my Mavic Pro last night i got a lot of compass error, GPS error, Yaw error, IMU error and even "Weak GPS Signal", but it was connected to 23 satellites, so it should not be weak/bad GPS-signal.
What could the reason be for all this errors?
I landed the Mavic and restarted it and flied a little more, now without any errors.

Here is the link to the logviewer: DJI Flight Log Viewer - PhantomHelp.com
And here is the DAT-file from the AC (i think it's the right one): Dropbox - DJI_ASSISTANT_EXPORT_FILE_2018-06-09_09-06-01.DAT

Any help would be appreciated :)
 

Jnse

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No military stuffs nearby but a military radar ~20km from here. (My Phantom 2 Vision have never behave strange here).
The area southwest is LKAB, a mining company.

Why do GPS stops working only because the compass gets error?
(the drone should be able to fly home no matter which way is back/front of it, so why does it "turn off" GPS just because of that?)
 

sar104

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Hi
When i fly my Mavic Pro last night i got a lot of compass error, GPS error, Yaw error, IMU error and even "Weak GPS Signal", but it was connected to 23 satellites, so it should not be weak/bad GPS-signal.
What could the reason be for all this errors?
I landed the Mavic and restarted it and flied a little more, now without any errors.

Here is the link to the logviewer: DJI Flight Log Viewer - PhantomHelp.com
And here is the DAT-file from the AC (i think it's the right one): Dropbox - DJI_ASSISTANT_EXPORT_FILE_2018-06-09_09-06-01.DAT

Any help would be appreciated :)

Those errors were all caused by compass problems. The IMU yaw was initialized after startup from compass 1 at -1°, but compass 2 disagreed at -26°. It appears that you were moving the aircraft around as you powered it up and immediately afterwards. There was significant disagreement after initialization between the IMU yaw and both compasses:

2018-06-09_09-06-01.FLY046_10_01.png

In unwrapped yaw space the early motion disagreement is even more obvious:

2018-06-09_09-06-01.FLY046_10_02.png

It's quite possible that this was simply due to the power up movement and possible magnetic interference. I would test that by placing it on the ground, powering up without moving it, and then flying and retrieving the DAT file for comparison.
 

Jnse

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Oh i might have done that, will try again without doing anything while powering it up.
Thanks for the help :)
 

Jnse

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BTW, what software do you open the DAT file with?

I did a new flight this evening and now everything worked, not a single warning (just high wind).
But i havent got time yet to copy the files to my PC.
 

sar104

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BTW, what software do you open the DAT file with?

I did a new flight this evening and now everything worked, not a single warning (just high wind).
But i havent got time yet to copy the files to my PC.

Converted to CSV using DatCon, visualized in Igor Pro.
 
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Jnse

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sar104

Dic mihi solum facta, domina.
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This is the data from the new flight.
I never saw any error message at the screen, except the "High wind" warning, but here was a compass error when looking at the DJi Logviewer.
DJi Logviewer: DJI Flight Log Viewer - PhantomHelp.com (Compass error at 6m 16.6s)
DAT-file from the AC: Dropbox - DJI_ASSISTANT_EXPORT_FILE_2018-06-10_07-45-41.DAT

Why did i get compass error this time?
I have not yet understood how "Igor" works, but i will try to figure it out :)

Have you calibrated the compasses? The compass 2 looks bad.

20180610_FLY053_01.png
 

Jnse

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