Project update

Bohdan.L.Bodnar at att.com Bohdan.L.Bodnar at att.com
Wed Aug 3 21:08:28 GMT 1994


Regarding sampling rates and acceleration enrichment:

Most sensors are sampled 10x/second on contemporary stock vehicles.  This
rate is chosen so as to make the operation "real-time" and so as not to
overload the cpu in the computer (keep in mind that up until a few years
ago, most cpus were 8 bit machines).  "Much faster" sampling will require,
other than a faster cpu, low-pass filtering before any ADCs (i.e., the
"anti-aliasing" filters).  On acceleration (and decel):

Fuel injector firing consists of two types:  synchronous and asynchronous.
Synchronous firing occurs in step with a sync signal (e.g., coming off of
the distributor's reference line) whereas asynchronous is triggered by
rapid changes in the throttle position sensor.  Asynchronous firing will occur
during acceleration AND deceleration.  To the best of my knowledge, most of
the work that you desire to do is done empirically.  SAE had a publication
(1992) whose name escapes me right now which dealt with engine transducers and
had some NEAT stuff on experimental adaptive engine controls.  If there's
enough interest, I can dig it up.

Cordially,

Bohdan Bodnar
bohdan.l.bodnar at att.com





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