The Research And Design Of Control System For Pure Electric Vehicle

The vehicle is the most widely used transportation by human. Because of the continuous development of the automotive industry, the number of the global vehicles, the energy consumed by cars and the exhaust emission of cars are increasing, which lead to environmental pollution and energy crisis, the two problems affecting the social development. Therefore, all countries in the word have been expanding the technology of the new energy vehicles, among which the pure electric vehicle with high energy utilization rate and low or zero emissions, is the main developing direction of the new energy vehicles in the world.In order to study the technology of the pure electric vehicle, our school cooperated with a car company to concert the seven seats MPV into a pure electric vehicle. This paper does part of research and design to the pure electric vehicle control system based on the conversion project.(1)The word of vehicle conversion was completed. Firstly, the structure of vehicle modification was determined, then the matching design of parameters of the motor, battery and transmission ratio was done according to the performance indexes.(2)After the completion of the vehicle conversion, this paper studied the vehicle control strategy based on the modified pure electric vehicle. Firstly, the control strategy depending on working conditions was researched, which analyzed the operation modes of the automobile and the judgment condition. Then based on fuzzy control, a strategy of acceleration torque control for pure electric vehicle was designed. During the acceleration of the vehicle, the fuzzy control is used to identify the driver’s acceleration intentions. According to the recognition results of intention to accelerate, reference torque is compensated based on standard torque in varying degrees, which improves the motor torque output in the acceleration and the acceleration performance of the pure electric vehicle.(3) In the Matlab/Simulink environment, the simulation model of vehicle control system was established, which was used to analyze the strategy of acceleration torque control for pure electric vehicle. The simulation analyses proved that the strategy can improve the motor torque output in the acceleration and the acceleration performance of the pure electric vehicle, and at the same time consider the economic performance. Then the simulation and analyses of the vehicle performance were done, which proved the vehicle performance meet the requirements.(4)The MC9S12XS128 was chosen as the main control chip to design the software and hardware of the vehicle controller for the pure electric vehicle.