AIR-FUEL RATIO CONTROL DEVICE FOR INTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To provide an air-fuel ratio control device capable of performing control stably and at high precision in controlling an air-fuel ratio in exhaust gas for setting concentration of a specified component in the exhaust gas to be a prescribed target value. SOLUTION: An air-fuel ratio operation quantity determining part 13 to determine operation quantity KCMD to prescribe air-fuel ratio of exhaust gas in such a way that output of an exhaust gas sensor 6 of an exhaust system of the internal combustion engine 1 becomes a prescribed target value is provided with a means to identify a parameter of a model of a system E as a subject to control. The air-fuel ratio operation quantity determining part 13 determines the operation quantity by selectively using the parameter identified value of the model and the prescribed value in accordance with operation conditions of the internal combustion engine 1.