Newly set up quad loiter drifting problems

Log Analysis -- deprecated Copter Logs -- deprecated
1

I just finished moving all of my components from a tricopter (which was working flawlessly) to a quad frame and am having some problems getting loiter working properly with 3.1. Whenever I put it in loiter, it starts to drift. It’s slow at first but then it seems to start circling faster and in a larger circle so I have to switch back to stabilize (testing in my driveway). I was having vibration issues before that I thought was causing this but now they are in acceptable ranges with new dampening. GPS was solid throughout the flight also so not sure what could be the problem. I’m uploading the log, be aware that it’s a whole flight of me autotuning the copter so the loiter attempt is near the end. If someone can tell me how to trim log files I can upload only the relevant part. It would be great if someone could help me out.

2

Hi Texag,

IDK if you already checked the loiter wiki where you can find information of tuning and troubleshooting of this mode:
copter.ardupilot.com/wiki/loiter-mode/

3

Spinning in a circle is something we refer to as toilet bowling

You have some compass interference happening.

See this section in the wiki
copter.ardupilot.com/wiki/ac_com … padvanced/

and in particular,
copter.ardupilot.com/wiki/ac_com … ESC_motors

4

[quote=“RogelioN”]Hi Texag,

IDK if you already checked the loiter wiki where you can find information of tuning and troubleshooting of this mode:
copter.ardupilot.com/wiki/loiter-mode/[/quote]

Thanks, I didn’t know about this.

5

[quote=“Craig3DR”]Spinning in a circle is something we refer to as toilet bowling

You have some compass interference happening.

See this section in the wiki
copter.ardupilot.com/wiki/ac_com … padvanced/

and in particular,
copter.ardupilot.com/wiki/ac_com … ESC_motors[/quote]

This seems to be the problem since holding yaw angle is also an issue. I’ll check out these links and see if I can get it working.

6

I have tried all of the compass calibration/declination procedures and am still having the same problem with yaw and loiter. The yaw seems to drift back and forth and the loiter just doesn’t stay put. I still haven’t tested in a large area to see the tendency with more space. Could this be because I am using a cheap external compass from ebay? I’m starting to think it’s just not able to provide good enough data to the APM.