Yaw Error?

Spark
1

Hey,

I was flying my spark the other week while out 4x4ing and it decided to fly off.

I can see that at 2:20 into the flight it suffered a Yaw Error then at 2:22 it exited GPS mode due to a magnetic field interface? Im struggling it understand that we it was 100mtr in the air.

This has happened a couple times now. Any help info would be much appreciated

https://www.phantomhelp.com/LogViewer/OLESLEMEJW8IK3745TVW/

2

This incident appears to be similar to a lot of other incidents where there is an unexplained difference in GPS derived velocity and IMU derived velocity. This has happened with other DJI platforms, especially the M2. It also appears to have happened in your previous incident 2018-10-15_[07-42-45]…

These incidents are not caused by a geomagnetically distorted launch site.

If you want to investigate further then please retrieve the .DAT from the Spark. Look here to see how to do that. TBH, I don’t think much will come of looking at the .DAT. But, you never know, yours could be the one that provides the insight needed to see what causes these incidents.

2 Likes
3

Hi Budwalker,

Is this the correct file? Share link from my Google drive

4

It may very well be but your drive is not configured correctly for sharing.

5

That should have fixed it?

6

As I mentioned the incident occurs when there is a difference in GPS derived velocity and IMU derived velocity. I noticed that these differences seem to be correlated with abrupt pitch changes. The latest flight looks like this

image
image836×615 28 KB

The top plot has the north velocity difference (blue) and the east (red) velocity difference. Pitch (blue) is shown in the bottom plot. Also included are the Y axis gyro data (green). I suspect the .DAT from the Spark itself will reveal a more pronounced correlation between the Y axis gyro data and the velocity differences.

These pitch changes were not the result of elevator inputs. Probably due to gusty wind conditions - although they seem to be a little abrupt. The AC .DAT would tell us more.

Your previous flight has pretty much the same phenomena.

What’s all this mean? I’d be interested to know if you’ve done an IMU calibration. Especially since the previous flight 10-15-2018. And, can you do an IMU calibration followed by a test flight then provide the .DAT for that flight. During the flight try giving it full forward elevator and once max speed is obtained give it full back elevator. This should result in some abrupt pitch changes.

@sar104

2 Likes
7

One more thing. Please don’t do a compass calibration. Otherwise, we’ll be left wondering if any changes are due to the IMU calibration od the compass calibration.

8

Hi BudWalker,

Thanks for the insight. This side of it is very new to me. Its good to know that its most likely not a user error.

I will do an IMU calibration and test flight and report back.

In the mean time thank you very much for the assistance.