Need altitude tuning help.

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Need altitude tuning help.

Postby importon » Thu Jan 29, 2015 3:15 am

I can't tell if what is happening here is classified as "AQ violently jumps up and down in position hold – high frequency." or "AQ violently jumps up and down in position hold – low frequency". Or perhaps it's something else.
Basically I'm stumped on which value to adjust to try and correct this.
Please see video, but more importantly listen to the audio.
you should hear a rhythmic revving of the throttle about once or twice every second to try and maintain height.
http://youtu.be/rLt5N1lehdw?t=37s
(alt hold engaged at :37 until end)
Any help would be greatly appreciated. Thanks!

Sorry I forgot to plug in the SD card on this flight so no log file :?
importon
 
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Re: Need altitude tuning help.

Postby chschmid » Thu Jan 29, 2015 4:00 pm

Have a look here. http://forum.autoquad.org/viewtopic.php?f=36&t=2115&p=10955&hilit=slow+sinking#p10955
Maybe the behaviour you describe is similar.
Cheers
Christof
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Re: Need altitude tuning help.

Postby LPR » Fri Jan 30, 2015 3:55 pm

Here's is some more information on Navi altitude control.

http://autoquad.org/wiki/wiki/configuri ... on-tuning/

Larry
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Re: Need altitude tuning help.

Postby importon » Fri Feb 13, 2015 3:20 am

Thanks for the help!
and sorry for the delay. got caught up with work and needed to put aq tuning on hold for a min.

So I have got the altitude hold working fairly smooth right now when the copter is hovering, but if I do some forward flight and then come to a stop/hover again the hold will drift up or down by about 4 to 7 feet and then return closer to the desired altitude.

I have tried many combinations of pid settings but cannot seem to get rid of the problem without creating another problem.

I do have a piece of soft breathable foam over the baro or the DIMU.

Any suggestions for settings to increase or decrease?

Also the ascending and descending speed when I give stick input is very slow for me. If I give it full throttle it climbs much slower than I would expect.
Will increasing "max decent rate" make it ascend/descend faster?

Thank you for your valuable help!
importon
 
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Re: Need altitude tuning help.

Postby Max » Fri Feb 13, 2015 3:43 am

importon wrote:but if I do some forward flight and then come to a stop/hover again the hold will drift up or down by about 4 to 7 feet and then return closer to the desired altitude.


This could be an ACC calibration issue. Which AQ are you using, and which calibration procedure(s) have you done?

You could check your ACC Magnitude as described in the Wiki calibration/checking section.

What motor mix are you using?

-Max
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Re: Need altitude tuning help.

Postby importon » Fri Feb 13, 2015 6:48 pm

Thanks for the reply Max.

I'm using the aq6 board v2 with DIMU. I have done the full freeze/thaw + calibso calibration. The logfiles looked good and the calculations seemed to go good as well.
Do you think I should try TARE as well? Will that mess up all my settings?
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Re: Need altitude tuning help.

Postby Max » Fri Feb 13, 2015 8:22 pm

Sure, tare only takes a second (once you level your MR), so it can't hurt. Save all your current onboard parameters to a file, which will preserve the current calibration data. You can also simply upload the generated parameters (from your full calibration) again if the tare doesn't improve things.

I'd still check the ACC Magnitude, before and after the tare. http://autoquad.org/wiki/wiki/configuri ... -influence

-Max
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Re: Need altitude tuning help.

Postby importon » Sun Feb 15, 2015 12:58 am

thanks again. I'm just reading that wiki page you sent me to and I can't find anything on there about baro sensor. Are you saying that my altitude hold problem is not from the baro but from the ACC and MAG?
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Re: Need altitude tuning help.

Postby Max » Sun Feb 15, 2015 1:12 am

importon wrote:Are you saying that my altitude hold problem is not from the baro but from the ACC and MAG?

Max wrote:This could be an ACC calibration issue.
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Re: Need altitude tuning help.

Postby importon » Sun Feb 15, 2015 5:02 am

gotcha.
Will do some testing and report back.
Thanks again!
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