Control device of internal combustion engine

A control system for an internal combustion engine provided with:

• a fuel injector for injecting fuel into an engine combustion chamber,
• an EGR system for recirculating part of the engine exhaust into the engine combustion chamber as EGR gas, and
• a cylinder pressure sensor for detecting a pressure inside the engine combustion chamber,
• said control system for an internal combustion engine provided with:
• combustion parameter calculating means for calculating a combustion parameter expressing an engine combustion state including at least one of a cylinder heat release amount, a combustion start timing, and a combustion period based on a relationship predetermined using the combustion chamber pressure detected by said cylinder pressure sensor and an engine crank angle and
• correcting means for correcting at least one of a fuel injection amount, fuel injection timing, and amount of EGR gas so that the calculated combustion parameter becomes a target value predetermined in accordance with the engine operating conditions and
• selecting as said combustion parameter a combustion parameter giving the smallest error in accordance with the fuel injection mode or combustion mode of the engine among a plurality of types of combustion parameters expressing said engine combustion state calculated based on the combustion chamber pressure and engine crank angle and using said selected combustion parameter for the correction by said correcting means.