CONTROLLER FOR PLANT, AND AIR-FUEL RATIO CONTROLLER FOR INTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To provide an air-fuel ratio controller for an internal combustion engine which can excellently perform control for making the output of an exhaust gas sensor arranged on the downstream side of a catalyst device converge on a specific target value with quick response irrelevantly to the output state of the exhaust gas sensor. SOLUTION: A manipulated variable generating means 7 which generates a target air-fuel ratio KCMD so that the output of an oxygen density sensor 5 on the downstream side of the catalyst device converges on the specific target value is equipped with a plurality of estimating means which generate by mutually different algorithms data showing estimated values of the output of the oxygen density sensor 5 after the waste time of an exhaustion system E or the total waste time obtained by adding the waste time of an exhaustion system E and the waste time of a system composed of an engine control means 8 and an engine 1. The manipulated variable generating means 7 generates the target air-fuel ratio KCMD by processing under adaptive sliding mode control using a value selected out of the estimated values or the value obtained by putting them together.