Control device for internal combustion engine and method for determining misfire in internal combustion engine

A control device for an internal combustion engine that generates power by burning an air-fuel mixture in a cylinder, comprising:

• in-cylinder pressure detecting means;
• calculating means that calculates a control parameter based on an in-cylinder pressure detected by the in-cylinder pressure detecting means and an in-cylinder volume at the time of detecting the in-cylinder pressure;
• and
• misfire determining means that determines a misfire condition in the cylinder based upon the control parameter calculated by the calculating means, wherein:
• the control parameter is a product of the in-cylinder pressure detected by the in-cylinder pressure detecting means and a value obtained by exponentiating the in-cylinder volume at the time of detecting the in-cylinder pressure by a predetermined index number;
• the calculating means calculates the control parameters in two predetermined points;
• and
• the misfire determining means determines that an inside of the cylinder is in a misfire condition by comparing a difference component in the control parameters between the two predetermined points with a predetermined threshold value.