APM1 Autotune

I finally got around to doing the autotune procedure today. Wind was close to none and I only had to re-position my quad about 4 times. The whole process took less than 5mins.

My quad is a jDrones v1 frame with 924kv Hacker Style 20-22L motors, HK SS Series 25-30A ESCs (stock firmware), 5000mah 3s LiPo and 11x4.7 GemFan props. Here are my before and after PIDs:
[attachment=0]quad1.jpg[/attachment]
Stab Roll/Pitch: 4.5000 - 5.2500

Rate Roll P: 0.1500 - 0.0800
Rate Roll I: 0.1000 - 0.0800
Rate Roll D: 0.0040 - 0.0040

Rate Pitch P: 0.1500 - 0.0550
Rate Pitch I: 0.1000 - 0.0550
Rate Pitch D: 0.0040 - 0.0040

My quad is now feeling rather sluggish - I guess due to the low Rate Roll/Pitch values. If anyone can go over my log files it would be greatly appreciated…

Thanks,

Hi Andre,
I haven’t seen this problem for a while but I believe it is caused by too much flex in the frame, the apm mounted on overly soft foam, a gimbal of some sort hanging off the copter or a loose battery could also cause the problem.

Do any of these things sound plausible?

Hi Leonard,

None of them sound applicable to me. My arms are square aluminium tubing and there’s no flex, the APM is mounted directly onto the carrier board, I don’t have a gimbal and the battery is tight. Here is a close-up shot of my APM…
[attachment=0]DSC00779.jpg[/attachment]
Thanks,

Should I maybe try the Autotune again starting with higher Rate/Roll P values or will I get similar results?

Hi Leonard,

I added some support to try and stiffen my carrierboard and now I get the following results:

ROLL:
P: 0.085
I: 0.085
D: 0.004

PITCH:
P: 0.145
I: 0.145
D: 0.010

This time the pitch tuning lasted a lot longer than the last time. I tried to upload the log files but I keep on getting a “The uploaded file is empty” error. I’ll try again later…

Hi Leonard,

Here are my log files…

Regards,