[LAD] Car engine sound emulation for future electic cars. ideas ?

[Fons Adriaensen]

On Sat, Aug 02, 2008 at 04:32:23AM +0200, David Olofson wrote:

> On Saturday 02 August 2008, Benno Senoner wrote:
> [...]
> > The sound generator should in theory take only one input variable,
> > the motor's RPM (which can expressed as 0..100%) and then generate
> > a sound with a frequency proportional to the RPM.
> 
> I think it'll need at least two parameters: rpm and throttle position. 

Yes. In fact it's three - road speed determines tire and aerodynamic
noise - but you can probably ignore that here.

> There is another problem, though: Electric cars tend to have very few 
> gears (commonly only one!), as they don't really need any, thanks to 
> the extremely wide power band of electric motors. This makes it 
> pretty hard to come up with a realistict combustion engine sounds, as 
> it's not just the sound that's missing; it's the entire driving 
> style!

One could also question why it should be 'combustion engine noise'.
If it's just to make other users of the road aware of the car's
presence and speed, it could as well be the sound of horseshoes
on a hard surface. Probably even better, as this is impulsive
and provides better localisation.

The data used by car manufacturers to describe engine noise
is a spectral description, where some small divider of the
RPM (depending on engine configuration) is regarded as the
funcdamental frequency. For each harmonic you have a smooth
amplitude  map in function of RPM and throttle position.

Staring from these it's not so difficult to synthesise
something quite realistic. 

Ciao,

-- 
FA

Laboratorio di Acustica ed Elettroacustica
Parma, Italia

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E guerra e morte !