The control apparatus for an internal combustion engine and method therefor

An apparatus controlling an internal combustion engine, which is provided with an EGR device having an EGR passage and an EGR valve which is provided in the EGR passage, and can set a EGR amount. This device comprises a control device, estimates the state parameters of the engine that affect the behavior of the EGR gas in a predetermined time period; sets limits on the EGR amount in the predetermined period on the basis of an approximate dynamics that is obtained by a proper dynamics is approximated, which is a transition of the EGR amount in the predetermined time period, so that approximate values ​​do not exceed the correct dynamics ; determines a target value of the EGR amount corresponding to the estimated state parameter in a region of the EGR amount, wherein the limits that have been set; and the EGR valve controls so that the EGR amount is the certain set value.