Adaptive Lean Air-Fuel Ratio Control and Analysis of Commercial Gasoline Engines

Abstract

This paper presents an adaptive lean air-fuel ratio control and analysis of commercial gasoline engines. There are two main parts in this research which are lean air-fuel ratio control and investigation of lean operation effects. Firstly, the adaptive control strategy is applied for the amount of fuel injection control while the spark advance is regulated for maintaining the engine torque by a calibrated look-up table. Secondly, the values of the location of peak pressure (LPP) and the location of 50% of the mass fraction burned (CA50) are used as main indicators for the lean combustion analysis. Finally, the net indicated mean effective pressure (IMEPn) is considered for the engine performance evaluation. The experimental results show that the applied control strategy has high performance for the lean operation mode of the commercial gasoline engine. In addition, the combustion parameters and IMEPn investigation can be used to analyze the effects of lean operation mode on the engine.