Rotational equalizer / Pirouette optimization

Hello,

I noticed that Futaba Gy750 and Microbeast feature a Rotational equalizer / Pirouette optimization function.

Is there such feature in VBar ?

Thanks

Thinking back ... a long time ago - we have such a feature since V4 - released in Spring 2009 ;-)

regards (EN) / Gruss (DE)

Rainer Vetter

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Thanks. Is there some setup to activate / adjust this feature ?

No - this was in V4 - but not needed in V5 - we have all neede information with the setup steps like sensor orientation, swashplate, collective direction, rotor direction etc ;-) - just simply try a pirouette in forward flight - just give tail only . It works.

regards (EN) / Gruss (DE)

Rainer Vetter

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
Posting and answering - please use a PC and a standard keyboard. Answer all questions fully, take the needed time, don't forget probably requested attachments.

Für Posts und Antworten bitte einen PC und eine richtige Taststaur benutzen sowie alle Fragen vollständig abarbeiten. Nehmt Euch Zeit, beantwortet Rückfragen in Ruhe und vollständig.
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Thanks

RV Wrote:
-------------------------------------------------------
> No - this was in V4 - but not needed in V5 - we
> have all neede information with the setup steps
> like sensor orientation, swashplate, collective
> direction, rotor direction etc ;-) - just simply
> try a pirouette in forward flight - just give tail
> only . It works.

Rainer,

I don't know if that question will make sense at all, but why then doesn't it work for example when I pirofunnel? I have to actively throw collective around when funneling. Is it because pirooptimizer equalizes only one out of the 3 axes that I have to control?

collective inputs? sure you did not mean cyclic inputs?

cyclic inputs are needed if you did not fly a straight line. A funnel is not a straight line, so you have to stirr the cyclics to maintain your path. This is what i expect from a perfect working piru correction.

so long ... Uli
http://www.vstabi.de

Ulrich, you're right - I ment cyclic.

So, that means prio correction is always related to a straight line. Now, when I would fly a straight line sideways, using let's say left aileron instead of elevator, would piro corr still work?

I'll try it as soon as rain stopps pouring down on us poor Colonites.

Thx a lot

Pet

No its not related to a sraight line, but there ist is most obvious.

In general the piro correction eliminates the effects of disk loading depending on the flying direction. If you load your rotordisk, it has the tendency to have balooning effects if you move it through the air. With paddels this is eliminated by a airflow that hits the rotordisk always from the direction, where it is moving, effecting in tilting the paddel disk towards the movement, doing the correction.
FBL do not have an sensor for the airflow, so this must be estimated. Additionally the rotordisk is a circular device, where it dosent matter in which direction it is mounted on the heli. On FBL this is different. The FBL System does not see the airflow, so the above estimation has to be rotated with the piruetting of the heli. That is what piro correction is doing. Additinally this explains, why there schould not be any parameters. You only can do it correct, or wrong. Its not adjustable. If there are parameters for setup, then its something different (in our terms).

Piro correction ist *not* visible if piruetting in still air! If piruettes are not flat there, the CG is probably wrong, or the Trimflight was bad. Most work is flying fast, during piruettes, mainly at high pitch angles.

so long ... Uli
http://www.vstabi.de

Please, what would be the effect of no "piro correction" ?

Rainer,

thx a lot for the explanation - an intellectually challenging but interesting topic!

@mrechte: if I am right, "ballooning" means that the various disc loads from piros will create heavy wobbles if not corrected. If you fly upside forward-nose-out you load the disc straight forward (right above the nose) from air flow. As soon as the nose starts to turn in (right or left makes only a slight difference depending on rotor direction) you are loading the disc sideways and unload it straight forward from the heli's perspective, which then will result in the nose going down and the side going up, as long as you do not compensate cyclic. For slow piros at hovering pitch level this compensation can possibly be done manually (if you are fast and somewhat trained) but for fast ones or pitched manouvers (funnels, piroflips etc.) that will be rather hard to do.

So, piro corr is a nice feature to make 3D flying easier for us no-frills hobby pilots. Pros could possibly do without it, I guess.

@Rainer, I still have another question regarding piros in still air together with cyclic throw. If you do them, theoretically swash servos wouldn't move, resulting in the disc to tilt along with the tail. How do you call the compensation that vbar takes care of in that case, holding the disc in its initial position with a fixed angle to the ground? If I am am right, other fbl systems call that "piro compensation".

Rgds
Pet



Edited 14 time(s). Last edit at 11/07/2013 12:04PM by PetJumper.

Thanks for this explanations. I am not sure I 've understood all

Ii Piro correction is not active, the effect can be seen i.e. with V3.6 of VBar wich has no piru correction. It does not have anti balloning as well, so it was a real plain PID control loop.

If you do a flyby, doing pirus, you will start to fly a curve if not corrected manually (direction of curve is the piru direction, left curve on left pirus and vice versa). If you do it with alot pressure = high speed, lots of collective, (and of course your tail has enough power) *without* correction, the heli will start to make a funnel all by himself!

Helis with flybar do compensate this with their flybar paddels. BTW these paddels are compensating for balloning as well, i.e. at least reducing the delfin effect (fly forward, push/pull collective). Vbar is doing this as well, most other systems do not!

so long ... Uli
http://www.vstabi.de