AIR-FUEL RATIO FEEDBACK CONTROLLER OF INTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To provide an air-fuel ratio feedback controller capable of suppressing a slippage of an air-fuel ratio from occurring when a disturbance is removed by correcting the slippage of the air-fuel ratio caused by the disturbance such as the recirculation of exhaust gas to a target air-fuel ratio by an integral operation. SOLUTION: The start (input) or stop (release) of the recirculation of exhaust gas is discriminated depending on whether or not an air-fuel ratio changes when a target air-fuel ratio is constant and the recirculation rate of the exhaust gas at that time matches a variation in the air-fuel ratio (S1 to S8). When the recirculation of the exhaust gas is stopped, the integral value of an air-fuel ratio deviation is reset to 0 (S9), and the correction to reduce the amount of fuel required during the execution of the recirculation of the exhaust gas is avoided to be performed.