Synthesis and estimation of cycle-to-cycle air-fuel mixture composition quality control in a spark ignition engine

Within the framework of the project No. 1785/T12/2001/20 entitled "New approach to air-fuel mixture composition control in the spark ignition engine, in transient conditions" sponsored by Polish Committee for Scientific Research, a new approach for cycle-to-cycle air-fuel mixture composition control in a spark ignition engine - named the CC method - was developed and verified. This way of control was also the main subject of a doctor's thesis defended in the Faculty of Mechanical Engineering at Technical University of Radom. This way of control is based on the assumption that air-fuel mixture composition will be in accordance with expectations only when, in the considered filling cycle, the amount of fuel delivered will result from the amount of air that filled the cylinder in this cycle. It means that achievement of such state needs air amount estimation before the filling cycle end, with such advance that allowed calculation and delivery of needed fuel amount in this cycle. A method of determination of cylinder fill with the use of HFM-5 air-mass meter was presented in the proceedings of the present Congress. This paper presents a method of control system synthesis in a spark ignition 1.61 engine with sequential multipoint gasoline injection. The ways of determination of so called preliminary injection map and complementary injection generation were presented. Quality of CC control method was presented showing fluctuation of the controlled cycle-to-cycle air-fuel mixture composition for sequential work point.