Control device for internal combustion engine

Abstract

An object is to provide a control device for an internal combustion engine, at an inexpensive price, whereby it is possible to suppress a decrease in the exhaust gas performance of the internal combustion engine due to an environmental change or damage from aging. The present invention relates to a control device for an internal combustion engine which controls an EGR amount by adjusting an opening degree of an EGR valve () disposed in an EGR channel (), the control device comprising temperature detection units (), a pressure detection unit (), a unit () to calculate a basic opening degree of the EGR valve, a unit () to calculate an estimate value of at least one of an air-excess ratio or an intake oxygen concentration on the basis of detection values obtained by the temperature detection units and the pressure detection unit, a unit () to calculate a target value of the estimate value, a unit () to calculate a correction factor K on the basis of the estimate air-excess ratio λs and the target air-excess ratio λt, a unit () to calculate the opening-degree command value D for the EGR valve on the basis of the basic opening degree Db and the correction coefficient K, and a unit () to control the EGR valve on the basis of the opening-degree command value D.