Patent ID: 8578909

Claim:
A control device for an internal combustion engine comprising: intake pipe pressure acquiring means for acquiring an intake pipe pressure of the internal combustion engine; in-cylinder pressure acquiring means for acquiring an in-cylinder pressure of the internal combustion engine; first corrected value calculating means for acquiring in-cylinder pressures at least twice every required period after an intake valve of a cylinder of the internal combustion engine is closed and before mixture in the cylinder is ignited by ignition means of the cylinder while acquiring in-cylinder volumes during acquisition of the in-cylinder pressures, and calculating a first corrected value using the acquired in-cylinder pressures, the in-cylinder volumes, and a specific heat ratio; second corrected value calculating means for calculating a second corrected value using the in-cylinder pressure and the intake pipe pressure acquired when the intake valve is opened; comparing means for comparing the required period with a set period determined in advance; and in-cylinder pressure correcting means for correcting the in-cylinder pressures acquired within the required period using the first corrected value when the required period is longer than the set period, and correcting the in-cylinder pressures acquired within the required period using the second corrected value when the required period is shorter than the set period.