Near loss in Atti mode (flyaway)

[nottery]

Here are my Compass Values @sar104

 

[nottery]

it looks to me like you're running FW 01.04.0400?

Yes @BudWalker i am running FW 01.04.0400

 

[BudWalker]

@sar104 I mentioned that I had never seen the compassError signal have a True value. Well, that being the case, I removed it from DatCon. There is now a beta version of DatCon (version 3.6.1) that has this signal. It's a State signal with name General:compassError.

http://www.datfile.net/DatCon/DatCon.3.6.1.zip

I looked at it briefly and there isn't much of a correlation between General:compassError and magMod. I'm out for the rest of today. Have fun

 

[BudWalker]

@nottery I took a another look. I don't really have an answer for you, just some observations and a few suggestions. This incident is unlike others that I've seen, particularly since the compassError takes on the value True several times. Only the DJI engineers know what this means but I think it's an indication that the FC doesn't like the magnetometer data. As I mentioned the FC isn't indicating that it doesn't have confidence in the values that it computes based on the IMU (gyros and accelerometers) as well as the magnetometer data. There is an important difference between confidence in the magnetometer data and confidence in the values computed from gyros, accelerometers and magnetometers. Apparently, the FC still had confidence in the latter while being suspicious of the former. From your description this didn't cause any problems (erratic flight) in the first part of the flight.

I've changed my mind. magMod is correlated with the compassErrors.

And, from the eventLog stream we have entries like
212.861 : 12182 [L-FDI]NS(0) COMPASS(0): fault on , over_large
216.561 : 12367 [L-FDI]NS(0) COMPASS(0): fault off, over_large
that correspond to the compassErrors

There are none of the usual indications that the launch site was geomagnetically distorted.

Have you installed an external device like a tracker?

My only suggestion is that a compass calibration be performed. Please provide the .DAT where the calibration was performed and the .DAT for the subsequent flight.

@sar104

 

[sar104]

@nottery I took a another look. I don't really have an answer for you, just some observations and a few suggestions. This incident is unlike others that I've seen, particularly since the compassError takes on the value True several times. Only the DJI engineers know what this means but I think it's an indication that the FC doesn't like the magnetometer data. As I mentioned the FC isn't indicating that it doesn't have confidence in the values that it computes based on the IMU (gyros and accelerometers) as well as the magnetometer data. There is an important difference between confidence in the magnetometer data and confidence in the values computed from gyros, accelerometers and magnetometers. Apparently, the FC still had confidence in the latter while being suspicious of the former. From your description this didn't cause any problems (erratic flight) in the first part of the flight.

I've changed my mind. magMod is correlated with the compassErrors.
View attachment 43974
And, from the eventLog stream we have entries like
212.861 : 12182 [L-FDI]NS(0) COMPASS(0): fault on , over_large
216.561 : 12367 [L-FDI]NS(0) COMPASS(0): fault off, over_large
that correspond to the compassErrors

There are none of the usual indications that the launch site was geomagnetically distorted.

Have you installed an external device like a tracker?

My only suggestion is that a compass calibration be performed. Please provide the .DAT where the calibration was performed and the .DAT for the subsequent flight.

@sar104

Agreed - that sums up what I see too.

 

[nottery]

Thanks for taking a look @BudWalker , I will do the calibration and a flight in the next few days and post the subsequent .DAT file for that flight.

Thanks again, Nick.

 

[BudWalker]

Thanks for taking a look @BudWalker , I will do the calibration and a flight in the next few days and post the subsequent .DAT file for that flight.

Thanks again, Nick.

And, the .DAT containing the calibration please.

 

[nottery]

@BudWalker

 

[nottery]

Just a quick update,

Went for a flight the other day at the same spot, performed a compass calibration just before the flight, everything went really well, there were no signs of compass errors or magnetic interference.

Which .Dat file contains the compass calibration?
Which .Dat files would you like me to upload?

the one from the FlightRecords folder? or
the one from AC, downloaded through DJI Assistant?
@BudWalker

Thanks, Nick.

 

[BudWalker]

Just a quick update,

Went for a flight the other day at the same spot, performed a compass calibration just before the flight, everything went really well, there were no signs of compass errors or magnetic interference.

Which .Dat file contains the compass calibration?
Which .Dat files would you like me to upload?

the one from the FlightRecords folder? or
the one from AC, downloaded through DJI Assistant?
@BudWalker

Thanks, Nick.

The .DAT downloaded through DJI Assistant

 

[nottery]

DJI_ASSISTANT_EXPORT_FILE_2018-08-28_14-27-38.DAT
@BudWalker

 

[BudWalker]

DJI_ASSISTANT_EXPORT_FILE_2018-08-28_14-27-38.DAT
@BudWalker

That seems to have fixed the problem. Do you have the .DATs for the flights preceding FLY035.DAT? I should have asked for this before since it will be overwritten when space is needed to record a new .DAT.

 

[nottery]

I will have a look for you, will this .dat be on the flight logs / records folder on the phone / tablet?
@BudWalker

 

[BudWalker]

I will have a look for you, will this .dat be on the flight logs / records folder on the phone / tablet?
@BudWalker

No, from the Mavic via the Assistant.