On transient air/fuel ratio control for gasoline engine on the basis of model identification

For further meet increasing tightening standard of exhaust emission, accurate transient air/fuel ratio control is the key technology for modern automotive gasoline engine. Transient fuel film model has been established for four-stroke gasoline engine, and the fuel film model parameter identification been studied with least squares method. The fuel film model parameters have been gained on the basis of mathematical calculation and air/fuel ratio model has been built. The fuel film compensation controller was designed and simulation was carried out. Comparison was made between the air/fuel ratio simulation results and the air/fuel ratio Collected in the bench experiment in transient states. Results showed that air/fuel ratio model built and fuel film model parameters identified have a high accuracy, and feed forward compensation controller can meet the practical air/fuel ratio control requirements during transient condition.