Closed loop operation...

[TAR]

Mark,

I am in the preliminary stages of EFI design using a M68HC11.  I am going
to get the thing running open loop first and add O2 and knock control once
all the maps are correct.  As far as I know, closed loop operation on most
factory ECU's consists of a look-up table with correction from the O2
sensor.  Usually, pulse width correction does not exceed around 10%
(somebody correct me if I'm wrong pls! I am still looking into cracked
factory source code and SAE references to figure this one out too).  I
figure the closer you can get your look-up table (ie: the less the O2
sensor has to adjust AFR), the better your engine will run, especially in
Limp-Home-Mode or in the event of an O2 sensor failure.

any feedback?

Todd-

On Tue, 16 Apr 1996, Nietzsche is dead. -God (aka Mark Hofmann)wrote:

<chomp>
> Speaking of closed loop operation, I'm having a difficult time uderstanding
> exactly how it works...  is it still a lookup table with a correction factor
> for the O2 sensor reading, or is it an autonomous system where just the
> O2 sensor controls the whole thing?
> 				--Mark
> Hofmann at uhavax.hartford.edu
> http://linux.hartford.edu/~mark

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Todd Ratke	e-mail:
		tratke at gpu.srv.ualberta.ca
 	  -or-  ratke at nyquist.ee.ualberta.ca
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