The Study Of Dynamic Emission Simulation Method Of Turbocharged Engine

With the increasing attention to the environment protection and the development of the automobile industry, the problem of the vehicle engine exhaust emission is concerned by the national authorities, research institutions, colleges and manufacturers. The development and research of the engine performance optimization, the emission control and the electronic control system is becoming a hot spot.The experimental method and the simulation method are usually used in the study of the turbocharged engine dynamic emission. Since the experimental method is restricted by the test equipments and the simulation method is affected by lots of factors when building mathematic models, the thesis adopted a method which was combined the engine steady emission experiments with the dynamic simulation. It set up the non-linear mapping relationship between the emission values and the running parameters relied on the engine steady experiments, and calculated the emission values under the dynamic running status.By using MATLAB/Simulink, this thesis built a dynamic emission prediction model of the turbocharged engine. Firstly, a quasi-linear dynamic model of the turbocharged diesel engine was built which was based on the mean value model theory. Secondly, a turbocharged diesel engine model was set up in the environment of Simulink and the engine operation parameters were calculated in the dynamic running status. Thirdly, the engine emission model was built by the neural network toolbox of MATLAB with the experimental data. It can acquire the non-linear mapping relationship between the emission values and the engine operation parameters. We can also validate the learning capability and the extension capability of the model. The simulation result was gained according to the experimental criterion of ECE-15. In the end, the model was running on the xPC, which is a real-time simulation and development platform of RTW environment.Modeling and simulation of the turbocharged engine dynamic emission was achieved in this thesis. Although this study has some problems to be discussed, it setup and practiced an advanced thought by using MATLAB/Simulink and provided some suggestions to the future study. At the same time, the author completed real-time simulation of the controlled object by the xPC Target toolbox of MATLAB. It supports the hardware-in-loop simulation of engine electronic control unit. It will absolutely play an important role in the engine electronic control technology.