ESTIMATION METHOD USING NON-LINEAR ADAPTIVE FILTER OF AIR-FUEL RATIO IN CYLINDER OF INTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To form a more detailed model of an exhaust process to provide an air-fuel ratio estimating model having higher robust performance for all the action points without needing steps for specifying. SOLUTION: The present invention relates to a method for estimating the air-fuel ratio in each cylinder of an internal combustion engine with exhaust circuit which includes a detector for measuring the air-fuel ratio. The estimating device based on a non-linear adaptive filter is coupled to a physical model indicating discharge of gas from a plurality of cylinders and movement of the gas in the exhaust circuit up to the detector. The estimating device is also coupled to an estimation value of the air-fuel ratio measured from at least one variable of the models of a total mass of exhaust gas and a mass of fresh air. COPYRIGHT: (C)2007,JPO&INPIT