Patent ID: 8046156

Claim:
A control apparatus for an internal combustion engine, comprising: cylinder pressure detection means for detecting a cylinder pressure, which is a pressure within a combustion chamber of the internal combustion engine; means for obtaining a combustion ratio on the basis of the detected cylinder pressure, the combustion ratio being a ratio of, a cumulative quantity of fuel which is a portion of fuel bunt within the combustion chamber until a predetermined timing and which contributed to work for a piston, to the total quantity of fuel which is a portion of all fuel bunt within the combustion chamber and which contributed to work for the piston; ignition means for controlling ignition timing of the engine such that the obtained combustion ratio coincides with a predetermined target combustion ratio and for igniting a gas mixture within the combustion chamber of the engine at the controlled ignition timing; full-combustion-correspondence-period estimation means for estimating a full combustion correspondence period on the basis of the ignition timing and the acquired combustion ratio, the full combustion correspondence period being a period from the ignition timing to a combustion completion time at which combustion of the gas mixture within the combustion chamber ends; and burnt-gas-quantity control means for controlling a quantity of a burnt gas contained in the gas mixture such that the estimated full combustion correspondence period coincides with a target full combustion correspondence period.