Establishment And Application Of The Parameters Optimal Model Of Transient Air-fuel Ratio Controller For Gasoline Engine

With the development of automobile industry in the field,people pay more attention to the environmental pollution which caused by automobile emissions.While the automobile exhaust emission regulations in the world have become more and more strict,and the energy is heavily short of in the world.Besides,the demand and dependence on the automobile market is becoming more and more severe.Therefore,it is essential to achieve the goals of the energy saving and emission control of the automobile,especially to achieve energy saving and emission control effectively under the transient conditions of a gasoline engine.It has a very important social significance and engineering application value to improve the fuel economy and reduce emissions of pollutants for automobiles.In the process of this study,first of all it treats the transient air-fuel ratio controller of gasoline engine as a research object,and through the theoretical research on theory and its performance analysis,find the control parameters,such as the intake flow prediction value,oil film parameters and fuel injection pulse width,which were caused by the transient air-fuel ratio controller to produce the deviations.Secondly,using the chaos optimization algorithm and the nonlinear prediction combination optimization method to establish the optimization model of intake flow prediction parameters and the optimization model of oil film parameters respectively,and then by using the multi-objective optimization method to establish the optimization model of fuel injection pulse width,and the three seed model above are integrated to calculate,so as to establish the parameters optimal model of transient air-fuel ratio controller of gasoline engine;Then through Matlab/Simulink to establish a parameters optimal simulation model of transient air-fuel ratio controller gasoline engine,the parameters optimization model is added before and after by caring out the simulation experiment under the transient working condition of gasoline engine.The simulation results of gas flow prediction parameters,oil film parameters,fuel injection pulse width parameters and transient air fuel ratio were compared and analyzed,and they verified the feasibility and effectiveness of the simulation model.Finally,the engine test bench was set up,and the application effect of the model was tested.Took the parameters optimal model of transient air-fuel ratio controllerto flash in the electronic control unit ECU of engine through in the form of the code,combined with the engine experiment platform and took the application in ring test,then comparative experiments of power,fuel consumption,emission and air-fuel ratio for engine acceleration transient conditions were carried out.Through the test result analysis to verify the establishment of the parameters optimal model of transient air-fuel ratio controller of gasoline engine could be successfully applied to the actual working condition,and effectively realized the optimal control of air-fuel ratio and improved the power,economy and emission performance of gasoline engine.Through simulation comparison and bench test results show that the parameters optimal model of transient air-fuel ratio controller which can carry on the optimal control of inlet flow prediction value,oil film parameters and fuel injection pulse width parameters under the transient operating conditions,the transient air-fuel ratio can effectively approximate to the theory air-fuel ratio,and with high stability at the same time.Further more,it can reduce the control error of transient air-fuel ratio,so as to improve the pow,fuel economy and emission performance of gasoline engine.