fuzzy logic controllers

[Christopher Bruno]

jb24 at chrysler.com wrote:
> 
> >>In a similar vein, are "learning" or "self tuning" controllers
> currently found in commercial automotive systems?
> 
> Thanks for any help,
> Jay<<
> 
> Another consideration for lookup tables is failure modes.  Suppose you
> lose a sensor, or many sensors to age or leaded fuel and so on.  The
> so-called 'limp-home' modes will operate with few operating sensors, do
> to a row in the lookup matrix for zero voltage or the like.  I'm not
> sure what it is but my truck will light the check engine light after
> hitting a few inches of water, cough and stumble for a little bit
> (maybe ingestion, but hard to imagine on a 4x4) and continue on, then
> find its breath again and the light goes out.  Any comments?
> 
> John Bucknell is jb24 at chrysler.com

I've thought about this because I've heard many stories about these
cars that have intakes WAY above the ground and then they die when 
they drive through a puddle only a few inches deep.  I wonder if it
has something to do with the Oxygen sensors on the exaust.  Some of
the O2 sensors are not heated and perhaps the splash of water on the
exhaust/sensor cools it to below the 600 degrees it needs to be
operating at and suddenly the car receives bogus data from the O2
sensor.  Even if the sensor were heated the heater may not be able to
react quickly enough to this kind of rapid heat loss.  Any comments?


-- 
Christopher Bruno
Teradyne
321 Harrison Ave. MS/H63
Boston, MA 02118
617.422.2040 Office
617.422.2304 Fax
bruno at icd.teradyne.com