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U.S. Department of Energy
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Air-fuel ration control system for an automotive engine

Patent ·
OSTI ID:6954150

An air-fuel ratio control system for an automotive engine is described comprising: an O/sub 2/-sensor for detecting oxygen concentration of exhaust gas and for producing a feedback signal; first means responsive to the feedback signal for producing an air-fuel ratio signal; second means for producing a deviation signal representing the air-fuel ratio dependent on the air-fuel ratio signal from a desired air-fuel ratio; a first lookup table storing basic fuel injection pulse widths from which one of pulse widths is derived in accordance with engine operating conditions; a second lookup table storing maximum correcting quantities for correcting a derived basic fuel injection pulse width in order to correct deviation of air-fuel ratio due to change of a characteristic of a device used in the engine; third means for producing a learning correcting quantity for correcting a learning coefficient for the maximum correcting quantities and for producing a corrected learning coefficient in dependence on the learning coefficient and learning correcting quantity; fourth means for producing a necessary correcting quantity by multiplying the corrected learning coefficient and a derived maximum correcting quantity; fifth means for producing a desired fuel injection pulse width in accordance with the necessary correcting quantity and the derived basic fuel injection pulse width.

Assignee:
Fuji Jukogyo Kabushiki Kaisha, Tokyo
Patent Number(s):
US 4741312
OSTI ID:
6954150
Country of Publication:
United States
Language:
English