Study on the combustion control methodology for maximizing of engine thermal efficiency — The strategy for control of heat release pattern

Exhaust Gas Recirculation (EGR) dilution / air lean Spark Ignition (SI) and Homogeneous Charge Compression Ignition (HCCI) engines have been developed to improve the engine thermal efficiency. One of the most important points of them is the improvement of the trade-off between the thermal efficiency and the combustion stability. The purpose of this research is to develop a control-method to achieve the full potential of the engine thermal efficiency. The methodology for adjusting the combustion to target heat-release pattern was proposed, and the method to minimize the parameters that should be controlled were discussed based on the combustion characteristics. The effectiveness of applying to homogenies lean-burn engine was described as an example.