Quadcopter Drifting in pos-hold after 10 minutes of flight

ArduCopter
1

Hi,

I am flying with arducopter in my multicopters more than 5 years, and this is the first time I can’t solve the problem by myself.

The problem is: after 9 or 10 minutes flying in pos-hold mode, my quad start to drift in circles. And the circles are bigger and bigger.
After this when I correct using the Stick, and after a few seconds the circles starts again.

But the stranger thing is, in the beginning of the flight pos-hold is “Rock solid”.

The setup is:
T-motors: Motors and ESCs
Raspberrypi3 + Navio2 board with arducopter 3.5 version.
Baterry = 6500mah

The Multi:

Normal Flight until 9 minuts (but i dont have the problem recorded, because I stoped the recording to “help” the multicopter)

Attached the Logs, thanks for any help.

2

The position drift is associated with a mag drift .

gkrellShoot_09-04-2018_170158
gkrellShoot_09-04-2018_170158.jpg1274×335 98.7 KB

Be careful , your battery went to a very low voltage, 9,4 Volts for a 4S battery means probably a cell is defective.

What propeller size ?
What is your AUW ?

3

Really Thanks a Lot,

regarding the battery I changed yesterday , realy bad.

Specs:
motors - T-motor 2814-10 kv770
Propeller - 12-4x5 Rctimer
ESC - T-motor 40
AUW = 1,8kg , the drone fly with 40% of throttle , these motors are strong.

But to fix this mag drift, what do you recommend ?
and only to my improvement, where did you read this mag drift in the graph ?

4

Please any help ? I have no idea how to fix this problem. (hope only me)

5

Could not see any obvious reason in the log for the toilet bowling, which doesn’t mean it is not there.

But what you describe is a typical compass problem.
Why it would build up like that I don’t know.
Maybe a build up in the EKF, that is where I would look.

Try disabling each Mag and see how it goes.

6

ok, I will.

lets see , really strange because the result on the fly is really bad, bud the logs looks ok.

7

Total guess but I’d say it could be the battery breaking down and causing interference.Look how everything calms down and settles right at the end of the graph as the current dies.

Just a thought.

8

putz…really good gues… really good… because the problem only happens after 8 minuts…thanks.