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Old pids with DIMU FW

PostPosted: Wed Jul 23, 2014 9:17 pm
by leopold1
After my close encouter with an AQ ;) http://forum.autoquad.org/viewtopic.php?f=24&t=3540
I reinstalled everything again from scratch and used the DIMU FW r406 again. And also looking out that all parameters were correct ;)

Onboard cal and tare went fine and stored everything.

But with the default pids it was quite unflyable. Yaw was uncontrolable and there was a fast oscillation.
Then I switched al my rate an angle pids back to the old ones from the non DIMU official fw. And it flies allmost perfect.

Someone give me a clue why this is?

Re: Old pids with DIMU FW

PostPosted: Thu Jul 24, 2014 4:07 am
by SuperSharpShooter
I've had to turn down the PIDs from defaults on all my DIMU copters to get them to fly smoothly. Not quite to the level of the old defaults, but around 30-40% generally.

Re: Old pids with DIMU FW

PostPosted: Sat Jul 26, 2014 9:22 pm
by leopold1
Glenn,

Which pids did you turn down 40%?

I reduced the new pid values for 60% for
Tilt rate P
Tilt angle P,I and D.
The rest I didn't touch. Its flyable but stil that odd twitch that I don't have on the version without DIMU.

Another question. I'm using Menno's r402 FW but I don't know if he uses default pids?

Re: Old pids with DIMU FW

PostPosted: Sat Jul 26, 2014 10:19 pm
by Max
For comparison, you could try out the other firmware I posted here, starting with default Tilt PIDs.

-Max

Re: Old pids with DIMU FW

PostPosted: Sun Jul 27, 2014 10:32 am
by leopold1
Max,

I loaded your fw and apart of the MPU filtering the pids are all the same as Menno's r406.

At first glance the test flight was more stable with small fast oscillations that was reduced to a minimum by reducing tilt rate D to 12000.

When I read the postings from http://forum.autoquad.org/viewtopic.php?f=27&t=3269&start=40 I get exactly the same motor "zinging". And it gets worse when hovering low (due to downwash)
Also when flying tilt and pitch a little bit faster you can here them motors zinging.

Hope this helps in finding a solution.

Re: Old pids with DIMU FW

PostPosted: Sun Jul 27, 2014 10:45 pm
by leopold1
Just went back again to the 6.7 stable version from the download section and my quad flies great without DIMU.
I'm concluding that it has nothing to do with vibrations or setup.

Re: Old pids with DIMU FW

PostPosted: Thu Jul 31, 2014 1:08 pm
by leopold1
Any more suggestions concerning the strange behaviour.

I'm going abroad for a couple of months and I'm thinking of taking the quad with me.

Re: Old pids with DIMU FW

PostPosted: Fri Aug 01, 2014 8:07 am
by hogster
leopold1 wrote:Just went back again to the 6.7 stable version from the download section and my quad flies great without DIMU.
I'm concluding that it has nothing to do with vibrations or setup.

Hi Leopold,

That is very interesting to hear, particularly that you were also experiencing the same 'zinging' problem as I'm having on my platform.

Can I just confirm that I don't need to remove the DIMU board if I want to go back to 6.7 and try using the AIMU?

My only fear is that I'm still experiencing quite bad shifts in my MAG values when hovering, and that with the AIMU this might have an affect on the stability of the platform ...?

Many thanks,

David :)

Re: Old pids with DIMU FW

PostPosted: Fri Aug 01, 2014 3:51 pm
by leopold1
When I switch back to the AIMU Fw I remove DIMU just in case ...
I would like to film the behaviour but I don't know if you will be able to hear the zing. Or maybe a log could shed some light??

One thing I don't have is a drift.

Nevertheless I hope it gets resolved because the only big advantage for me at the moment with the DIMU is the alt hold. It works very good!