Re: A simuv2 backport of the clutch/gear-change inertia fix

On Thu, 10 Jan 2008 09:54:59 +0100, "Frieder Ferlemann"
<[email protected]> said:
> Hi,
> 
> Christos Dimitrakakis schrieb:
> > It is not clear how to determine braking from the engine parameters, 
> > which is why we have 'engine brake' parameter F.  From what you say, I 
> > think that if F is set correctly according to each engine, the model 
> > type (a constant + linear factor for braking) is adequate and the only 
> > question is how to determine F.
> 
> If the engine inertia is known and one has the sound of the engine
> rev'ing down while the clutch is open one could try to derive it
> from there. Probably would work well for non-turbo engines?
> 

Sure, but there are difficulties:

1) Collecting the data.

2) Estimating the rpm from the sound.  I have tried that in order to
convert engine sounds to the steady-rpm we need for the game.  It's not
easy.  It's probably best to create a statistical inference model that
directly infers a constant and a linear deceleration parameter from the
sound data.

3) This procedure will only give you the friction up to a multiplicative
factor.  Resolving this will require knowledge of the engine inertia. 
This will require data from revving up and matching it with the known
torque of the engine.

I used the following simple method to setup a car that is similar to the
one I drive:

1) Count the time needed to revup to redline
2) Count the time needed to revdown to idle.

Tweak inertia to fit revup time.  Tweak friction to fit revdown time.

-- 
  Christos Dimitrakakis
  [email protected]

-- 
http://www.fastmail.fm - Send your email first class


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