Search Results

An advanced and practical fuel injection control system to reduce exhaust gas emissions has been developed. This control uses an exhaust air-fuel ratio (EAFR) sensor and a heated exhaust oxygen (HEO) sensor. The air fuel ratio of exhaust gas is precisely converged to stoichiometry. The integrated deviation of the mass of fuel inducted into the cylinder is rapidly converged to zero, so as to maximize the conversion efficiency of catalysts. The controller is derived from the models that express the dynamic phenomena. The experimental results show the effectiveness of this system for future exhaust emissions and enhanced evaporative emissions.

In order to satisfy future demands of low exhaust emission vehicles (LEV), a new fuel injection control system has been developed for SI engines with three-way catalytic converters. An universal exhaust gas oxygen sensor (UEGO) is mounted on the exhaust manifold upstream of the catalytic converter to rapidly feedback the UEGO output signal and a heated exhaust gas oxygen sensor (HEGO) is mounted on the outlet of the converter to achieve an exact air fuel ratio control at stoichiometry. The control law is derived from mathematical models of dynamic air flow, fuel flow and exhaust oxygen sensors (HEGO and UEGO). Experimental results on FTP (Federal Test Procedure) exhaust emissions show a dramatic reduction of HC, CO and NOx emissions and a possibility of practical low emission vehicles at low cost.