Copter 3.5 rc7 autotune does not start - help!

ArduCopter Copter 3.5
1

trying to start autotune in 3.5 rc7 with no result. it changes the mode but no “dance”

https://drive.google.com/file/d/0B7kzd6bkY1FXS21PYWFyb0hLVWc/view?usp=sharing

2

Which mode did You use when starting AUTOTUNE ?
Had the same … Then did it in PosHold with centered stick (throttle) … Worked fine.
You have to wait a little for the dance … Does not start immediately !
Christoph

3

Tried so far alt hold and loiter. Maybe 10 sec waited. Previous version rc5 pos hold was prety good now it is drifting alot.

4

The most common reason it won’t start is because the sticks aren’t perfectly centered. A few other people bumped into this so I added a section to the wiki: http://ardupilot.org/copter/docs/autotune.html#common-problems

We are also increasing the deadzone on the sticks a bit for -rc8 which I plan to release out today.

Thanks for testing!

5

Since then i have done couple test with rc8
https://drive.google.com/file/d/0B7kzd6bkY1FXcjNrTHdvSDRkRHc/view?usp=sharing
https://drive.google.com/file/d/0B7kzd6bkY1FXTnRYdjRPWldCVVU/view?usp=sharing
https://drive.google.com/file/d/0B7kzd6bkY1FXanRKV29GVWhnSEE/view?usp=sharing

rc1234 dead zone was incresead to 50.
pid where lowered
no way of making it start autotune.

Also can you point to where can i download the Copter 3.5-rc1 compiled ?
Plan is to try autotune with an older version and change back to rc8 and retry autotune

Thanks for your help!

6

DZ is not a problem here, try this: I’ve seen it help sometimes:
you tune roll axis, do a fast input on the roll stick, only 10-15% of the travel, enough to cause a small twitch, and let it quickly go back to center , you can expect to “trigger” one of the tuning twitches. - repeat …
I’ve used that method on a huge octo that did not want to twitch unless I did that.
I suspect your Z vibrations could be the cause, I also had some more z vibrations on that machine than I would like to have. (thanks to big folding props)

7

Thanks Andre-K,
i have observed this motion, question is, have you done this till the end or just to start the "dance"
Also seen a suggestion to lower the filter for roll and pitch to 5hz instead of 10hz. Have you tried that ?

8

I have successfully completed a tune of one axis by that method.
Yes, I’ve reduced filter too prior to that, not sure I went down to 5Hz, but at least 10 or 8. that did not help - I think. But you should try.

9

Hi,

Maybe check if you have trim values setup in your parameters or on your rc transmitter.

I had similar issues for a while until I realized that i had trim values both in the parameters and on the rc - when I removed them (set to zero) things improved.

The other thing I noticed that autotune worked more reliable when I removed the anti-vibration dampening mount and attached the pixhawk directly to the frame.

Chris