AIR-FUEL RATIO CONTROLLER FOR INTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To suitably restricting a manipulated variable, and improve controllability to a target value outputted from an exhaust gas sensor while ensuring stability of an engine operating condition by variably setting according to the manipulated variable, an allowable range of limit processing for restricting a value of the manipulated variable from a manipulated variable generating means to a value within a predetermined allowable range. SOLUTION: A target air-fuel ratio generating processing unit 28 is disposed in an exhaust side control unit for carrying out processing for gradually generating a target air-fuel ratio of an engine in a control unit of the engine. The processing unit 28 is provided with a manipulated variable generating unit 29 for generating a manipulated variable for operating an air-fuel ratio of the engine in order to converge an output of an O2 sensor to a target value using a deviation output kact of a LAF sensor by a subtraction processing unit 12 and a deviation output VO2 of the O2 sensor by a subtraction processing unit 13. The processing unit 28 is provided with a limiter 30 wherein limit processing for restricting the manipulated variable to a value within an allowable range which is variably set according to the manipulated variable is carried out to the manipulated variable, and an addition processing unit 31 for adding an air-fuel ratio reference value which is set in a set unit 11 to the manipulated variable.