This is a discussion re the ArduCopter-3.1 AutoTune feature.  A place for people to report successes and failures, ask questions and get answers.

The AutoTune wiki page is here.


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Hi Anthony,

I am glad it is working for you! You probably don't know what you are missing with all that manual tuning :)

Welcome to multirotors! 

no ideas i just wanted to compare it to my y6(6s batt,420kv motors,15x5props,5kg)

"You probably don't know what you are missing with all that manual tuning :)" so true..i wish autotune was here when i started...thank you again developers...waiting for no rain day to try again...

Hi Josh,

No the D term isn't too high. This is one of the classic issues I have seen make Autotune fail. We are still trying to work out what causes this issue but we do know that too much flex in the frame, apm mount, or poor CG can do it, large props on underpowered motors might also do it.

What is happening here is Autotune is trying to reduce the Rate P until the measured rate doesn't exceed the requested rate. The problem is that it can't do this without dropping the Rate_P dangerously low (<0.02) so it stops.

What is your setup. Props, motors, battery (mAh and cell count), all up weight and frame.

Hi Josh,

No I haven't got to that yet. The difficulty is I have to explain how Autotune works in order to understand the logs. This isn't too bad but might take me a day of messing around to generate the pictures and text to go with them (writing isn't my strong suit). It just hasn't got to the top of my list yet.

And no, you don't need to be connected to the MP for Autotune to work.

Can you share some details about your new first quad?

Picture, technical param, etc. With help. Thanks.

I did not yet AutoTune my quad yet (home made), but I will do it and share that info also.

I really like the autotune feature. I first tried it with my tricopter and it worked very well.

When I tried it on my Y6 I had some issues, I described in this thread:

I now understand, that I have to do the autotune without camera and with the batteries fixed very ridged to the frame.

I will give it a try when weather and my time allow me to do.

When reading this thread and thinking about the autotune feature, I had some ideas.

The autotune lasts about 6-8 minutes, in windy conditions, where you have to bring back the copter for several times, it could last really long. When you have a copter with flighttimes less than that, you have a problem.

So I thin a good idea would be, to have a parameter to split the autotun into parts.

For example give the possibility to tune roll and pitch in extra sessions with battery change in between.

It also could be helpfull to just tune the rate PIDs and do the Stab PIDs in an extra run.

It is not an issue with one of my copters, because I have enough flight time for a complete autotune, but maybe someone could have problems with it, if it runs for 8 minutes. O.k., 8 minutes will be close to the end of my batteries at the Y6.

Alright well i bit the bullet and gave autotune a try. I have a 3DR Y6 with 850 motors, 30amp AfroESC's. I removed my camera/gimbal for this autotune.



Few Questions:

-Does Autotune modify YAW PIDs at all? those values stayed the same

-Is it safe to revert back to 3.0.1 and input these new values? I don't want to fly around with a release candidate, but I want to use these new PID's; just want to make sure there are no major differences between 3.0.1 & 3.1rc5 on how it interprets PID's.

-The copter feels VERY locked in - maybe too much. I do plan to FPV, so if I want a smoother ride, do I lower Stab roll P & Stab pitch P?

I plan to try a few real flights later so will report back.. just want to make sure it's OK to revert back to 3.0.1 with these new PID's before venturing out.

Thank you for a great feature! I wish it was around when I first put together my Y6!

- No, Autotune does not modify the Yaw PID's at all.  

- Yes, I believe you can revert back to 3.0.1 and run those PIDS. I can't recall any recent changes to the rate controllers that would affect this, though I'd like confirmation from Leonard.  Acro mode is completely changed with 3.1, but I don't think that's what you're interested in.

- Yes, if you lower Stab Pitch and Roll P, that will make it fly a bit "softer", but you will lose some of the locked in feel.

Hey Leonard,

Frame is an ADS 400-Q, it weighs ~1.1kg before the battery and just over 1.5kg with the battery

Motors are SunnySky X2216 1100kv

Battery is the 4S 3300 35-70 Nanotech

Props are currently the HQ E Props at 8x5 but I also run the gemfam carbon mix slow-fly props at 8x4.5

I remounted the APM with stiffer foam per an earlier recommendation you gave and that has helped this machine as well as my QAV500G significantly (on which I have not yet tried AutoTune).  

The frame is not only resilient but pretty stuff.  Admittedly it'll twist a bit if I grab opposing arms and try, but for the most part it doesn't mess around too much.

I got AT to finish yesterday by decreasing the I values a little bit at a time until it would finally go, and it set Roll's P and I terms to 300 and brought D down to 45 I believe it was.  I'm going to FPV and see how it goes today, but I believe this is the value it found last time and you said you didn't like it.  That was a month or so ago, before the re-mounting of the APM.  I suspect I'll have to lift the I back up again, but we'll see.  Out of the issues you listed above, the only one that may fit is frame flex unfortunately.  It's not visibly flexing during autotune, and its certainly not a wet noodle up there, but CG is spot on and the mount is pretty good now.

Ah thanks.  If I could help with the write-up I would;  I don't enjoy write-ups any more than the next guy, but I'm sure some of the questions I've flung your way would be answered in there, so hopefully you're able to find some time to knock it out between your day job and answering all these support requests :)

Hi Arbobeginner,

Yeh I agree. We are also going to be adding Alt_Hold tuning and maybe yaw tuning soon so we are going to need to do this. I am thinking something like:

0: Roll/Pitch Rate and Stab

1: Roll

2: Pitch

3: Yaw

4: Alt_Hold

But we will need to see how long each axis takes to tune on average.

Thanks for the feedback mate!!

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