Mavic Air Fly-away

[BudWalker]

......but what is ATTI_MINI0_s?

Maybe it's the "vision compass" we've been hearing about. The s_qw0, .., s_qz0 is almost certainly a quaternion. s_pgz0, s_vgz0, s_agz0 are probably Z position, Z velocity and Z acceleration in some frame of reference.

 

[sar104]

Maybe it's the "vision compass" we've been hearing about. The s_qw0, .., s_qz0 is almost certainly a quaternion. s_pgz0, s_vgz0, s_agz0 are probably Z position, Z velocity and Z acceleration in some frame of reference.

The q values are quaternions - I processed them to get the qpitchM, qrollM and qyawM values in the graphs above, as well as MyawM.

 

[EYE_IN_THE_SKY]

A month ago, I had a fly-away with Mavic Air. It was the first fly-away in over 5 years since I used drones. I sent the drones to service and got a new one. The DJI guarantee worked perfectly. (I mention that I did not have DJI insurance).

My problem is that I have not received a satisfactory response to what happened exactly.

Moreover, both the old and the new one have the same problem: a few seconds after takeoff random have a short spin on the YAW of about 10 degrees left. As far as I read, I'm not the only one with this problem. I want to know if there is any link between this odd behavior and the fly away.

Before sending the drone to the service, I saved the .DAT file from the drone. Can you help me read it and to interpret the data? Thank you

 

[sar104]

A month ago, I had a fly-away with Mavic Air. It was the first fly-away in over 5 years since I used drones. I sent the drones to service and got a new one. The DJI guarantee worked perfectly. (I mention that I did not have DJI insurance).

My problem is that I have not received a satisfactory response to what happened exactly.

Moreover, both the old and the new one have the same problem: a few seconds after takeoff random have a short spin on the YAW of about 10 degrees left. As far as I read, I'm not the only one with this problem. I want to know if there is any link between this odd behavior and the fly away.

Before sending the drone to the service, I saved the .DAT file from the drone. Can you help me read it and to interpret the data? Thank you

If you post a link to it on Dropbox etc., then probably yes. I recommend starting a new thread for that.

 

[EYE_IN_THE_SKY]

If you post a link to it on Dropbox etc., then probably yes. I recommend starting a new thread for that.

DJI_ASSISTANT_EXPORT_FILE_2018-06-06_17-29-00.DAT

 

[BudWalker]

DJI_ASSISTANT_EXPORT_FILE_2018-06-06_17-29-00.DAT

The Mavic Air .DAT files are encrypted. But, you could provide the .DAT from the tablet instead. Look here to see how to do that.

 

[BudWalker]

A month ago, I had a fly-away with Mavic Air. It was the first fly-away in over 5 years since I used drones. I sent the drones to service and got a new one. The DJI guarantee worked perfectly. (I mention that I did not have DJI insurance).

My problem is that I have not received a satisfactory response to what happened exactly.

Moreover, both the old and the new one have the same problem: a few seconds after takeoff random have a short spin on the YAW of about 10 degrees left. As far as I read, I'm not the only one with this problem. I want to know if there is any link between this odd behavior and the fly away.

Before sending the drone to the service, I saved the .DAT file from the drone. Can you help me read it and to interpret the data? Thank you

When this happens are you launching before you see GPSMode in the Go App? I.e. is it saying something like OptiMode instead? Another indication that you're launching in OptiMode is that the gpsHealth indicator is showing 3 or less. That's the GPS bar graph display on the RC

 

[EYE_IN_THE_SKY]

When this happens are you launching before you see GPSMode in the Go App? I.e. is it saying something like OptiMode instead? Another indication that you're launching in OptiMode is that the gpsHealth indicator is showing 3 or less. That's the GPS bar graph display on the RC

View attachment 43063

At takeoff 9 satellites. At the moment of fly away 18. I forgot to mention: it was night.

 

[BudWalker]

At takeoff 9 satellites. At the moment of fly away 18. I forgot to mention: it was night.

Sorry, I was talking about this
have a short spin on the YAW of about 10 degrees left.
Is the MA in OptiMode at launch when this happens?

 

[EYE_IN_THE_SKY]

Sorry, I was talking about this
have a short spin on the YAW of about 10 degrees left.
Is the MA in OptiMode at launch when this happens?

GPS signal was good. Last time 13 sats

 

[BudWalker]

GPS signal was good. Last time 13 sats

Although a sufficient number of satellites is important it's not the real story. gpsHealth is a measure of the FC's confidence in the coords that it computes from GPS and IMU data. If gpsHealth is less than 4 then the MA will not be in GPS mode.

With 13 satellites the gpsHealth was probably 4 or 5 and your MA would have been in GPS mode. But, it isn't always the case. Here is an example where numSats was 15 but gpsHealth was 2.


Why you may ask is this related to the initial Yaw drift. Initially, Yaw is set to the magnetic heading determined by the compass. When gpsHealth gets to 4 the computed coords are used to determine the geoDeclination. Using the geoDeclination the Yaw value will be corrected so that it reflects the true heading and not the magnetic heading. I'm speculating that if this correction is done while flying the FC will see this as an error that needs to be corrected. And, it's known that the FC will attempt to reconcile a magYaw/Yaw separation by rotating the AC.

You made the comment that your Yaw drift was like that seen by others. Not quite. The others that I've seen would rotate either CCW or CW by a varying amount. You had stated your rotation was always to the left by 10°.