Drone drifting in PosHold with UM982 moving baseline

ArduCopter
1

Hello,

I am using Cube Orange+ mini with Holybro UM982 dual antenna moving baseline GPS on ArduCopter 4.6.2.

The drone arms and flies, but in PosHold mode it drifts and does not hold position properly, even in low wind. GPS lock is good (~28 sats, HDOP ~0.6) and heading is correct. It’s on 3d fix not on 3d lock.

I am attaching the log file for analysis.

Also, sometimes on power-up I get:

PreArm: Internal errors 0x80000

This goes away after reboot.

Is the drifting normal without RTK corrections, or is there any configuration issue?
And is the internal error related?

Thank you.

2

If you are using your system without a fixed base station you also have only standard accuaracy also for your moving baseline. There for a little drift is normal as long it is not a steady drift over a long time. The satcount and HDOP are not showing how good is the your accuarcy at the your positon and time.
How clear was the the sky view on your position. If there are some buildings or trees nearby accuaracy drops

3

Well there were lot of trees plus buildings but yesterday I flied again in different area with less trees and building then it’s wasn’t drifting. But Sky was clear in both locations.

4

“Trees and buildings” is the opposite of “clear sky view” (which has nothing to do with clouds).

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5

but what about the internal error 0x80000. How to resolve it. I have tried reflashing my firmware but it isn’t going away

6

Without doing a deep dive, I think that might be SD card related. Try a different one?

Also, use LOITER instead of POSHOLD. It’s a better mode in almost all respects for most use cases.

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