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What releases and functionality planned for vems 2012

Started by Jamo, January 30, 2012, 10:43:01 AM

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fphil

Quote from: GintsK on June 14, 2012, 11:53:32 AM
Andrey has also much more stable engine phase angle reading algorithm
Indeed I noticed that the phase angle speed or rpm is too much noisy for a physical value. I guess (!!) that value is given through an instantaneous and simple computation of the time derivative of the phase angle.
Next, possibly, these values are averaged to make a reference fo the next revolution.

Equally we havegot some delay for the engine to start because during this starting mode the computed speed is much changing especially when we have few triggers.

If this is the case, this is an old story from the sixties ( I was dealing with dynamic ship positionning systems some years ago) People use Kalman filters (or so) to  mild the data with a mixed of prediction based on a simple physical model (one mode) and of measured data, or even a serie of those filters with the combination parameters being scaled according to the speed.
Kalman was American, but Russian know the same technic very well.

Philippe

Jamo

Still no news on knock alternative? I've begun looking around at what other ecu's offer in terms of knock detection and vems is lacking at the moment.  Have to say i'm tempted to switch ecu

billman

Quote from: Jamo on July 19, 2012, 10:45:55 PM
Still no news on knock alternative? I've begun looking around at what other ecu's offer in terms of knock detection and vems is lacking at the moment.  Have to say i'm tempted to switch ecu

Quite usefull for all cars (motorsport and daily driven. Instead of iButton and stuff that almost nobody uses why don't they concentrate on this?

Arvid

Quote from: billman on July 20, 2012, 04:31:47 PM
Quote from: Jamo on July 19, 2012, 10:45:55 PM
Still no news on knock alternative? I've begun looking around at what other ecu's offer in terms of knock detection and vems is lacking at the moment.  Have to say i'm tempted to switch ecu

Quite usefull for all cars (motorsport and daily driven. Instead of iButton and stuff that almost nobody uses why don't they concentrate on this?

Really hope that developers prioritize Knock sensing. Here I live we have to drive 70 km to buy 98 octane gasoline. Is too little sales on 98 octane they say. :-(

Arvid

Still no knock alternative code? Some news?

Do really want to try knock alternative :)

Erikk

Emil asked me a few weeks ago if i had time to put a car on the dyno and torture into knocking, so i guess there´s something going on.

fphil

 fw version 1.2.9 offered a new boostcontrol algorithm. Does someone know what was wrong with the previous one and the new performances expected from this one.
Does it only deals with possible overshot issue? How does it solve that case?
Of course, nice to know the test cases !!

Erikk

The new boost is really cool.

The reference table is Boosttarget based, so when its tuned you´ll only need to change boost target and the ref-dc follows (good for anytrim etc..)
Also a new spoolup function, you can choose to max the boost-dc until it closes up to target.

And also a few more stages to give excellent boostcontrol. (PD only and then DI only with some overlapping).


The old strategy is still avaliable if someone doesnt like the new one

GintsK

From description it seems now we have have possibilities to chose when which PID component comes in action depending from actual/target condition.

IMHO previous main problem was I component: it should be small or strictly limited. Because of that bias DC table was always below actual DC at target. I came in action early and made actual DC already disturbed during boost build. But we want I acting during close to target situations. Anyway boost was tunable very nicely and fast (with good hardware).

I think now we have very useful improvement.

Gints

gunni

Does it have the 3d P term I was wanting?

I´m happy it has the BoostTarget vs rpm DCref table I wanted, and which I believe will vastly improve boost targetting for almost all scenarios.

I haven´t had time to hook up a ecu and check it out yet.


fphil

QuoteI haven´t had time to hook up a ecu and check it out yet.
Neither did I. I spent some time on the bench with the previous algorithm and I have not yet fully understood its logic (2 sides refDC, minboost_minpressure,.) or vocabulary.
Indeed what we need is to know more about the validation tests  used, or at least, config+ log data for 2 or 3 reference cases running standard boost control.

ID control is a new way which as Erikk said can be used close to the boost target to counter-react the fast  increase of the boost, although the P action is usually much smaller that D action when entering that zone and that without P action to damp the motions, you get overlaps, or if D can be set exactly for a nice landing in some cases, a non robust regulator. When rallying, outside this regulation zone, of course I is shut and D action is useless

Kamuto

Vems installer in Lithuania
[email protected]

Arvid

Quote from: Kamuto on February 23, 2013, 09:29:48 PM
so how knock testing are going?

I am also excited about how the knock testing are going?
Have an old Volvo B230k motor, which I can torture with Knock firmware :)