AIr-Fuel Ratio Controls For Clean Gasoline Engines

The mainstream of low emission technology for gasoline engines is an accurate air-fuel ratio control. The air-fuel ratio control maintains air-fuel ratio of combustion gas at the suitable target value to maximize emission conversion efficiency of three-way catalyst. Several model based controls have been applied to air-fuel ratio controls in order to meet strict emission legislations in the world. In this paper, modeling methods and control algorithms for air-fuel ratio controls will be introduced.