| As the deficiency of petroleum resources and the pollution of environment, conventional vehicle exposes lots of shortcomings. And EV(electric vehicle) technology about battery storage will not be resolved in short time, so developing and producing HEV(hybrid electric vehicle) is necessary. Hybrid electric transit bus runs mainly in downtown, because city public transit is very crowded, and stops frequently, so the work condition of engine is very bad, which brings the waste of fuel and the serious pollution problems. So in this condition HEV can just develop its advantages. HEV can realize many functions such as electric power start, zero emission, optimizing the work condition of engine and so on, which will not be realized in conventional vehicle. When studying and developing HEV, some problems must be considered, such as how to choose parts, how to ascertain the best construction, how to optimize the control strategy and so on. It may just resolve the problems above by using simulation technology. Simulation technology can help us adjust to design project and optimize design parameter, so it is not only good for reducing the outlay and time of test but also convenient to provide engineering objects for the production of HEV. Now, there are two main simulation methods about HEV: backward simulation and forward simulation. The process of backward simulation is simple, and the calculating speed is fast. But it is more proper for analyzing and comparing different design project than for developing the real system. On the other hand, forward simulation can simulate the actual characteristic of vehicle especially for the steering characteristic of drivers, and can guide us to design the hardware parts of system. So it is necessary for us to develop the forward simulation software. Based on the 863 project—the development of control system of hybrid electric transit bus power train, the main content of this thesis is for two parts: one is to design the forward simulation model for hybrid electric transit bus, the other is to develop the forward simulation software of HEV. In this thesis the process and important points of designing forward simulation model are introduced. The first thing is to analyze the work characteristic of all parts, and choose the mathematical model for the parts according to their construction and function. Next thing is modeling for them by using MATLAB/Simulation. Then it is to design the driver model and the control strategy model. About control strategy control object is to reduce the fuel consumption and exhaust emission and control method is defining logic limited value to confine the running range of battery and engine. At last, different kinds of models were connected, which ensure the transmission of the signals between them. In the same time, the control strategy about the work state of clutch and the shifting regulation were introduced. The forward simulation software of HEV, CHEV2004, is also introduced in this thesis. The main work is to edit the interface program of the software. The GUI graph instrument of MATLAB was used to make the interface of software. The most important thing in this part is to edit the callback function...
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