Yaw errors in middle of flight

[jimlips]

Greetings:

I broke out my P3A this afternoon, charged the batteries, and took it for a flight nearby. Everything was going fine, when the video feed looked like the aircraft was tilting, for some reason. It was also flying a little squirrely. I'll upload the unedited video so you can see what I'm talking about:

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. The Yaw errors start about 5:12 into the video. You can see the horizon tilt, and the aircraft went into ATTI mode at 5:31. I manually flew it home just fine. I'll provide a link to my data on AirData UAV. Here is the link: I can also upload the data in a different way, if you like. I'd really like to figure out what happened. After I brought it back home, I landed, inserted new battery, took off and flew around some more with no incidents. What causes "Yaw errors"?

 

[Meta4]

I'd really like to figure out what happened. After I brought it back home, I landed, inserted new battery, took off and flew around some more with no incidents. What causes "Yaw errors"?

You were lucky. Many yaw error incidents end badly.
The usual cause is launching from an area where local magnetic fields cause the IMU to get a false idea of where north is.
Later in the flight, the flight controller can't resolve the different readings it's getting from the compass and the IMU.

What can you say about the launch spot?

 

[jimlips]

You were lucky. Many yaw error incidents end badly.

The usual cause is launching from an area where local magnetic fields cause the IMU to get a false idea of where north is.
Later in the flight, the flight controller can't resolve the different readings it's getting from the compass and the IMU.

What can you say about the launch spot?

Thanks for your reply. I've flown from the launch spot at least 25 times. It is a dirt/grass field, no metal whatsoever. I guess it is possible that when the yaw errors started (about 5:31), there was a strong magnetic field in that location? I was up about 390 feet, so it must have been a heck strong one.

 

[Meta4]

Thanks for your reply. I've flown from the launch spot at least 25 times. It is a dirt/grass field, no metal whatsoever. I guess it is possible that when the yaw errors started (about 5:31), there was a strong magnetic field in that location? I was up about 390 feet, so it must have been a heck strong one.

Yaw errors are caused by a problem where you power on the drone and not because you flew close to something later.
Your drone ended up with a false indication of where north is and during the flight after you've left the magnetic field that caused the problem you've turned the drone and the compass reading doesn't agree with what the flight controller expects it to be.
If your are 390 feet in the air, no amount of steel on the ground would be able to cause any problems with your compass.

 

[jimlips]

Yaw errors are caused by a problem where you power on the drone and not because you flew close to something later.
Your drone ended up with a false indication of where north is and during the flight after you've left the magnetic field that caused the problem you've turned the drone and the compass reading doesn't agree with what the flight controller expects it to be.
If your are 390 feet in the air, no amount of steel on the ground would be able to cause any problems with your compass.

More on this; I flew the P3A again yesterday, and it worked fine, with the exception of it complained of a compass error, and suggested powering off and on again to clear it. So I did. Then it seemed fine. I flew one battery, came back, and installed another battery. Same error appeared again (magnetic compass error). So I powered it off and back on. Then it flew OK. Can I get replacement magnetic compasses? Is it hard to replace? Or do you think it may be the main board causing this on my P3A? Maybe time to sell it As-Is on Ebay?

 

[Meta4]

More on this; I flew the P3A again yesterday, and it worked fine, with the exception of it complained of a compass error, and suggested powering off and on again to clear it. So I did. Then it seemed fine. I flew one battery, came back, and installed another battery. Same error appeared again (magnetic compass error). So I powered it off and back on. Then it flew OK. Can I get replacement magnetic compasses? Is it hard to replace? Or do you think it may be the main board causing this on my P3A?

Is there really a problem with your compass, or is it working properly and warning you of magnetic interference like it's supposed to when the drone is close to steel objects or live electric currents?