Overshoot in RTH

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Overshoot in RTH

Postby plexus » Fri Feb 22, 2013 12:44 pm

I overshoot the point .
I reduced the value in Tilt rate D :6800 to 4900 by step 100 and also the value of Tilt angle D: 1800 to 1400 by step 100 but no change in the result.
What is the other parameter to see ?
Alain

The video:
http://www.youtube.com/watch?v=d7PPE2of ... e=youtu.be
tilt.jpg

special.jpg

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plexus
 
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Re: Overshoot in RTH

Postby LPR » Sat Feb 23, 2013 8:16 pm

plexus

I've built three very different AQ copters and they all have flown very well with all default PID values except for Tilt rate D. I find it very strange but that is what I found. The ONLY PID I change is Tilt rate D. I lower it till I see a little oscillation in the copter while hovering and then raise D till oscillations stops. Most of the copters will oscillate at 4000 and I'm using between 4500 and 5800 for tilt rate D on all of them.

Then to further adjust the D value watch the copter stop when you use RTH. If it overshoots then you need to lower D.

If you copter oscillates with default PIDs I find you have to control vibrations or a setting is wrong.

I'm now adjusting PIDs to get faster response to find the limits that the AQ can do.

Larry
Last edited by LPR on Mon Feb 25, 2013 3:10 pm, edited 1 time in total.
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Re: Overshoot in RTH

Postby plexus » Sun Feb 24, 2013 10:52 am

Thanks for the reply Larry. I no have oscillation.I have 2 things to adjust, the overshoot but the action on the tilt rate D/I change nothing. May be an other parameter to tune, but I dont know which .
The other thing is the throttle stick for hover in Hold position; It is very very critical and not stable. I put the dead band to 60 but it not that. In the GCS the Throttle 0 is at 750. May be too high ???
To day it is not possible to fly, snow and cold wind. The winter is not finished !!!
trottle0.jpg
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Re: Overshoot in RTH

Postby LPR » Sun Feb 24, 2013 2:43 pm

Plexus

I found you will not be able to fix your overshoot without going back to default PIDs and when adjust Tilt Rate D. At least I could never get there.

I found that it's fun to fly in winter. You break less props in snow. You have to seal all electronics to fly in snow.

http://www.youtube.com/watch?v=YwYjOIZDnM4

Larry
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Re: Overshoot in RTH

Postby plexus » Sun Feb 24, 2013 5:17 pm

Hi larry, so bad wheather. In south of France we have chance to not have that.
Anyway I see your Octo like to fly in gusty wind.
Be care with the electronic, she dont like water.
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Re: Overshoot in RTH

Postby LPR » Sun Feb 24, 2013 6:02 pm

plexus

Je ne pense pas que votre compréhension que je suis en train de vous dire. Je vais essayer de traduire du français et de voir si cela fonctionne.

J'ai trouvé vous ne serez pas en mesure de réparer votre dépassement sans utiliser PID par défaut et quand régler Taux Tilt D. Réglage PID beaucoup ne marchera jamais pour moi.

J'ai trouvé que c'est amusant de voler en hiver. Vous cassez moins les accessoires dans la neige.
Vous devez fermer et sceller soigneusement tous les appareils électroniques de voler dans la neige.
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Re: Overshoot in RTH

Postby plexus » Sun Feb 24, 2013 6:13 pm

I well understood Larry.
But changing Tilt rate D and I, don't reduce the overshoot of my hexa.
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Re: Overshoot in RTH

Postby LPR » Sun Feb 24, 2013 6:41 pm

Alain

Did you first change your PIDs to defaults? To get the PID back to defaults you can reload the Firmware, parameter file, motor mix file and any other setup stuff. Don't change any PID other than Tilt rate D and my experience is that you will be able to stop the overshoot.

Larry
Last edited by LPR on Sun Feb 24, 2013 7:02 pm, edited 1 time in total.
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Re: Overshoot in RTH

Postby plexus » Sun Feb 24, 2013 6:47 pm

Hi Larry,
That's a good question. I will try to reload the firmware and see if anything changed.
Just waiting the weather a little bit better!!!
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Re: Overshoot in RTH

Postby kinderkram » Sun Feb 24, 2013 9:09 pm

If running into a dead end street it's sometimes best to start from scratch.
Though in this case I doubt it will get better if using the same parameters. Did you control how many sats you have there?
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