Patent ID: 6026795
Filing Date: 2000-02-22
Classification: F02D

Abstract:
Electronic device for controlling an air/fuel ratio of a mixture of air and fuel supplied to an internal-combustion engine (2), characterized in that it comprises:linear oxygen sensor means (20) arranged on a gas exhaust pipe (5) of the said engine (2) upstream of a catalytic converter (8) on the pipe (5);converter means (22, 24) for receiving a signal generated by the said linear oxygen sensor means (20) to generate at an output of the converter means a measured parameter (.lambda.m) representing the air/fuel ratio of the mixture supplied to the said engine (2);setting means (27) for receiving information signals measured at least partially in the said engine for generating at its output a target parameter (.lambda.o) representing a desired air/fuel ratio;comparison means (20) for receiving said measured parameter (.lambda.m) and said target parameter (.lambda.o) and providing at its output an error parameter representing a difference between said measured parameter (.lambda.m) and said target parameter (.lambda.o;bistable probe simulator means (32) having an input for receiving said error parameter to generate alternately at an output of the bistable probe simulator means, a dummy signal comprising a positive saturation value (-P1 ) and a negative saturation value (-P1 ) which correspond to a bistable output of an oxygen sensor of ON/OFF type;processing means (36) communicating at its input with the output of the said bistable probe simulator means (32) for calculating, on the basis of said dummy signal, a correction parameter (KO2) to be applied to a theoretical value (Qb) denoting a calculated quantity of fuel (40) so as to obtain a corrected quantity of fuel (Qbt) to be supplied by a fuel injection system (10) of the said engine (2).