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Permalink Reply by Wesley Chuen on May 10, 2012 at 11:39am

I think Stable Mode only controlling your copter staying up right.  When it's stable enough, you can start tuning the attitude hold mode.  When that is done, you can then tune the position hold or Loitering mode.

To tune a parameter, usually you zero out the I and D and just tune the P until it get close to what it suppose to do, then you tune the I, etc.

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DeveloperPermalink Reply by R_Lefebvre on May 10, 2012 at 1:19pm

The Stable mode for the Quads uses both the Stabilize and the Rate PID controls.  Wesley is correct that the easiest thing to do is zero out the I and D terms, then just work with the P terms.  Unfortunately you are still left with a nested P term which can be difficult to tune.  The only hint I can give there is that excessive Rate P will tend to give really high frequency wobbles, or possibly even pulsing in the motors resulting in an undetectable wobble.  I suspect that would be the behaviour if the Rate P was very high.

Stabilize P being too high will result in larger but slower wobbling.

I'd suggest going back to default PID's, and zero out Stab I and D, and Rate I and D.  If it's reasonably stable, the work on Rate I next, as I think it's the next most important.

The up and down, I can't really explain if you are in stabilize mode.

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Permalink Reply by kman4UAV on May 10, 2012 at 8:00pm

Thanks Wesly & R_Lefebvre for your quick response..Today i got some time to try what you guys told me..Not bad felt little bit comfortable and still using lot's of stick moments with Step 1 : As showing in the picture(let me know if this is what you guys meant).

Tomorrow I will try tuning "I" in in-flight mode by using CH6 option.I will update the results.

Btw regarding throttle issue..I am constantly  giving the throttle to keep it in a certain height.Any suggestions pl's let me know.

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Permalink Reply by Stephen R Mann on May 14, 2012 at 5:10am

The I and D to the P...

Can you guys step it back for a really newbie? 

I haven't finished building my hexacopter and now I read about tuning and terms that are a totally new language to me.  Is there a manual anywhere that explains tuning?  and what does I, P and D mean?

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Permalink Reply by kman4UAV on May 14, 2012 at 6:11am

This is where i started from..

http://code.google.com/p/arducopter/wiki/AC2_Tweaks

I am also having hard-time regarding the WiKi manual which is kind of old and not clear for newbie's..I hope DIY team will put little effort to come up with a detailed manual.

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Permalink Reply by Stephen R Mann on May 14, 2012 at 6:26am

Many thanks Kman - this helps explain a lot and the idea of spending upwards of $1000 isn't as scary. 

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Permalink Reply by Francisc Bereczky on October 10, 2012 at 7:17am

Is there any rule of PID tuning dependant of the mass and dimensions of a copter?

I mean something like biger distance between motors needs greater/smaller P values or havier copter needs greater/smaller P values.  The same question for Stab_P and Rate_P.

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