Patent ID: 6286494
Filing Date: 2001-09-11
Classification: F02D

Abstract:
An air-fuel ratio controller for an engine comprising a wide range air-fuel ratio sensor for outputting a signal corresponding to an air-fuel ratio of an exhaust gas; and a calculating component for calculating an air-fuel ratio correction coefficient to control an amount of fuel supplied to the engine based on an output signal of said air-fuel ratio sensor, wherein:said calculating component calculates the air-fuel ratio correction coefficient based on a non-linear calculation element;said calculating component comprises a component for calculating a target air-fuel ratio; a component for calculating a real air-fuel ratio based on the output signal of said wide range air-fuel ratio sensor; a component for calculating an air-fuel ratio difference by comparing said target air-fuel ratio and said real air-fuel ratio; and a control component for calculating an air-fuel ratio correction coefficient based on said air-fuel ratio difference; andsaid control component calculates the air-fuel ratio correction coefficient based on said air-fuel ratio difference by at least one control out of a proportional control, an integral control and a differential control.