Baro problem or PID? [semi-solved]

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Baro problem or PID? [semi-solved]

Postby jet » Sun Jun 07, 2015 3:25 am

Hi, all.
Recently, I met a problem regarding altitude drop.
I had put a foam between DIMU and AQ6 to cover the barometer.

Yesterday, I spent 8 hours to do various tests.
However, I cannot overcome this problem.

Every test was 15 minutes.
In position mode, I let my AQ 6 flied forward again and again.
For the previous 3-4 minutes, the altitude was held well.
Then, the altitude was dropped.
The mag and acc were close to 2.1 and 9.8, respectively.
No visible vibration existed in the log files.
I also tried various foam materials.
The similar altitude drop occurred again and again.
Based on the tests, the accuracy of Baro became bad associated with time.

Does anyone have any solution?
Is the configuration of PID not well?
Thanks a lot.
Last edited by jet on Fri Jul 03, 2015 2:18 am, edited 1 time in total.
jet
 
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Re: Baro problem or PID?

Postby plexus » Sun Jun 07, 2015 5:48 am

Hi,
The best way is to upload your log to see what to do.
Alain
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Re: Baro problem or PID?

Postby jet » Mon Jun 08, 2015 8:52 am

Thanks Alain,
My AQ6 crashed today because of some tests.
However, before it crashed, I recorded a video and some photos regarding log.
Is it possible to define the problem causing Altitude drop?
The video: https://www.dropbox.com/s/scf9zzol35suk ... t.AVI?dl=0
The photos:
Clearly, the difference between pressu_alt and alt was high.
Any suggestions?
Thanks again.
Attachments
alt.jpg
ALT
alt.jpg (32.17 KiB) Viewed 5696 times
mag.jpg
MAG
mag.jpg (73.82 KiB) Viewed 5696 times
acc.jpg
ACC
acc.jpg (27.11 KiB) Viewed 5696 times
jet
 
Posts: 69
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Re: Baro problem or PID?

Postby plexus » Mon Jun 08, 2015 10:28 am

Hi,
To me it is difficult to see what happens with your log.
Can you post the Hacc and Vacc and too the ACCx with coordonates visible in flight hold is possible.
It will be instructive to see the curves of your motors (motor 0...3)
Your 3 seconds video is not explicit.
sorry for your crash

Alain
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Re: Baro problem or PID?

Postby Florian75 » Mon Jun 08, 2015 9:38 pm

Hello,

sorry for your crash :-(

Your altitude problem sounds to me for the "altitude speed P" "altitude speed "and "P max" Parameter. I set them both to 750. EDIT: No! Wrong Values. (I set "P max" = 150, "I max = 700, "Out max" = 700. ) Without increasing this, my copter comes down verry fast (sometimes).

Another Thing is the Trottle Factor. Do you have corrected it?

Regards
Florian
Last edited by Florian75 on Tue Jun 09, 2015 9:22 am, edited 1 time in total.
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Re: Baro problem or PID?

Postby jet » Tue Jun 09, 2015 1:34 am

Thanks plexus and Florian,
Yes, I had corrected Throttle Factor.
However, I did not revised "P max."
I am repairing my AQ6 now.
I will test these suggestions.
Thanks again.
jet
 
Posts: 69
Joined: Wed Mar 05, 2014 2:23 am

Re: Baro problem or PID?

Postby jet » Tue Jun 09, 2015 10:02 am

Hi, all.
My AQ6 was repaired with new motors, ESC, and prop (balance was done).
I tested my AQ6 again.
However, altitude drop still existed.
I had uploaded my log file (https://www.dropbox.com/s/k8wbw3g7hlx37 ... L.LOG?dl=0).
Based on the suggestion of Florian, my P/I/O max in altitude were 150/700/700, as figure shown.
Does anyone have any solution?
Appreciate you all.
Attachments
alt.jpg
Alt
alt.jpg (15.66 KiB) Viewed 5643 times
mot.jpg
Motors
mot.jpg (36.93 KiB) Viewed 5643 times
haac.jpg
HACC
haac.jpg (20.66 KiB) Viewed 5643 times
mag.jpg
MAG
mag.jpg (38.34 KiB) Viewed 5643 times
acc.jpg
ACC
acc.jpg (21.41 KiB) Viewed 5643 times
pid.jpg
PID
pid.jpg (77.1 KiB) Viewed 5643 times
jet
 
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Re: Baro problem or PID?

Postby Florian75 » Tue Jun 09, 2015 9:17 pm

Hy Jet,

please Set "I Max" and "Out Max" to 750 and try again.

And your "Nav Alt Speed P" is verry low. Default is 200.

regards
Florian
Florian75
 
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Re: Baro problem or PID?

Postby jet » Wed Jun 10, 2015 1:04 am

Hi, Florian.
I had tried I/Out Max from 650 to 800.
Also, I tried to increase Tilt Angle P and decrease Tilt Rate D.
Altitude drop still exited.
So sad.
I may let AQ6 fly too low since the height of these tests was 2M.
Thanks a lot.
jet
 
Posts: 69
Joined: Wed Mar 05, 2014 2:23 am

Re: Baro problem or PID?

Postby chschmid » Wed Jun 10, 2015 5:14 am

Hi Jet

Can you post a pict of how you covered the baro with foam please.

Cheers
Christof
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