Design On Control System For Four-wheel Independent Drive Electric Vehicle

With the world widely increasing the shortage of fossil fuel and environment pollution, the importance of development of electric vehicle(EV) technology is recognized. The four-wheel independent drive EV is one of the developing directions for further EV. Because of its perfect controlling performance and potential in engineering applications, more and more efforts have been devoted to the four-wheel independent drive EV by both academicians and engineers alike. It has been a hotspot of research.This thesis complies with the current issue, provides an overview of the situation of development of four-wheel independent drive EV, home and abroad. This paper focuses on the control system of four-wheel independent drive EV and applies theory into practice. By the design and realization of the complete control system, this paper shows practical significance.In the paper, firstly, the collectivity project of control system of four-wheel independent drive EV is built up with description and specification of structure. Every kind of bodywork sensor and electrical equipment are selected suitably. Compared with the control system of the fuel car, control strategy of whole vehicle of four-wheel independent drive EV is discussed. Then, bodywork speed is known as the best control project. When four-wheel independent drive EV is running as basic run mode that regularity speed straightly, speed up or speed down and turning, how to realize is discussed.Then, the paper concretely analyses and researches three parts:wheel motor drive controller, whole vehicle controller and CAN communication network, making up of the control system of four-wheel independent drive EV. On the base of selecting wheel motor, the paper deeply researches work principle, maths model and control blue print for wheel brushless DC motor. The hardware and software of wheel motor drive controller based on PIC18F4480 are designed. Wheel motor's double closed loop speed regulate control is realized. The programme of Electron commutator and speed/current PID regulation is Stressly specified. The whole vehicle controller based on TMS320F2812 is designed with description of hardware makeup. The whole vehicle controller is content to request of system function, easy to emulator and debug, easy to extend. The design of topology of the communication net and application layer protocol is analysed deeply. CAN2.0B is selected as bus communication protocol. Standard data frame is selected. The priority of news is arranged. The corresponding relation between ID and priority of news is given. software of the CAN communication is detailed in the paper.