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Delayed inertial steering

PostPosted: Thu Apr 11, 2013 7:02 pm
by Andrej
Spent week to tune PIDs and problem still exists - every command from RC come to late and with huge inertia.
With lowering P and D it is possible to get multi more agile but it also become less stable and in spite of this not execute all commands instant like it should.

Nevertheless AQ could be accurate and fast when executes the command go home, it just instantly make sharp and accurate turn without any lag or inertia. I am using Graupner PPM so I suppose it could be problem of PPM decrypt ?
Tried it with quadro and on octo.

Re: Slow and inertial steering

PostPosted: Thu Apr 11, 2013 11:35 pm
by LPR
Andre

What you are finding is exactly what I found and that is the way the AQ is. The AQ is designed to take videos and moving quickly in manual mode makes poor video. The AQ is much better at flying smooth in high wind when other flight controller I have used.
To adjust the PID so you can have faster manual control you can raise the tilt position P and and lower D but you will get oscillation if you adjust them too far.
You may get faster control by using Tx expo to increase the range of pitch and roll inputs.
I think it is a good trade off to have slow manual control to get precision mission control and great flights in high winds.

Larry

Re: Slow and inertial steering

PostPosted: Fri Apr 12, 2013 12:51 am
by Andrej
Lags add nothing to smoothing and stability, just interferences.
It is worth noting that crisp and accurate steering has only positive influence.
As I said, on AQ we can get a relatively quick steering style (when all the handles are of high magnitude) yet still lags and inertia present.
For instance MK or MW has possibility to tune for different style and not one of this style has lag or inertia, WKM is enough stable and smoth but it has a direct and instant steering.
For those who likes difficulties it is good to make options (up to 10sec delay), but not all users should struggle with this.

Interference for steering should not be seen as a feature for stable flight.

Re: Slow and inertial steering

PostPosted: Fri Apr 12, 2013 3:20 am
by LPR
Andre

I don't know if it is necessary or not to have the lag in the manual mode but since i see no reason to fly in manual very often I'm not complaining about it.
Have a look at how the AQ can do in the challenge to fly a cube.

viewtopic.php?f=24&t=2193

Now look at other autopilot and I think you can see why AQ is different.

http://diydrones.com/profiles/blogs/t3- ... 0#comments

Larry

Re: Slow and inertial steering

PostPosted: Fri Apr 12, 2013 3:45 am
by Max
Andrej,

I guess "lag" is relative, but I've never noticed any significant lag when controlling my AQs. It's not a sports machine and the tilt rates are limited, but I would certainly call the controls "crisp." When in PH mode, it may seem less reactive of course, since you have to go past the deadzone to activate DVH, but in manual I don't think you should feel any lag. It will of course still auto-stabilize, so if you're comparing it to a gyro-only setup, it will certainly feel different. But again, I wouldn't call it a lag in control.

I'm thinking you have something off in your setup. 10s delay sounds very wrong.

-Max

Re: Slow and inertial steering

PostPosted: Fri Apr 12, 2013 10:30 am
by Andrej
..I am not talking about gyro mode.

My experiments allow me to get big amplitude and fast speed between points of transition, but delay still present.
It just few tens of miliseconds but has huge influence on quality of managment.


This is definitely lag, not rate or amplitude.

Re: Delayed inertial steering

PostPosted: Fri Apr 12, 2013 11:09 am
by Andrej
The problems clearly evident during flights in cramped conditions, when the advantage has to be on the side of slow, smooth and stable system, but the AQ are reversed ... several times my multis touch branches of trees because of delays. This problem does not exist in other systems, even if they are set in a much more blunt and restricted modes than AQ. You will not feel this lags and inertia if you not fly on some alternatives.

Re: Delayed inertial steering

PostPosted: Fri Apr 12, 2013 12:21 pm
by GoFaster
Hi Andrej -

Can you please tell us about your muliti - what motors, props, ESCs/firmware etc you are using?
Post a log too.

- Felix

Re: Delayed inertial steering

PostPosted: Fri Apr 12, 2013 12:28 pm
by Andrej
Quadro
MT2216-900
10x4.5
BS30/Simonk
3-4s

Okto
MT2208
8x4.5
BS20a/Simonk
3s

Graupner PPM connection