Research And Design Of Mini-Electric Vehicle Control System

With the rapid development of the global automotive industry and the gradually increase of the global automobile production and sales every year, the amount of our country’s auto production and sales had reached 18 millions in 2010, and the growth rate has increased by more than 30% comparing with the last year. However, at the same time, the situations also brought about many serious problems. The shortage of oil is the most severe global problem during the 21st century, which caused much damage to the sustainable development of human being increasingly. On the one hand, there is a conflict between the supply and demand of the oil resources. China’s oil consumption is ranked the second only behind the United States in the world, and the domestic oil prices rose sharply, which increased the oil cost of traditional vehicles; on the other hand, the environmental problems caused by conventional vehicles such as the emissions of pollutants and dust are detrimental to the urban environment, which damage people’s quality of life. Facing to the shortcomings of the conventional vehicles, it is essential for us to adopt new energy vehicles to replace the conventional vehicles. New energy vehicles include the following contents:hybrid vehicles, fuel cell vehicles, electric vehicles and so on. Among them, the pure electric vehicles are considered to be the best way to handle the traditional vehicles problems.The pure electric vehicles are used as energy storage devices through a battery, which is driven by a motor. The key point of pure electric vehicles is the distribution of the energy and power. The pure electric vehicle controller is able to fulfill the function. The main point of this paper is to design such a pure electric vehicle controller.This paper combines the current situations and problems of the pure electric vehicles from the domestic to the foreign, makes an analysis of structure of pure electric mini-car vehicle, propose the designing parameters of the vehicle controller, and then design the system software and hardware accordingly. The CAN bus communication network is established to control the other controller for the purpose of management, communication and coordination.During the period of circuit hardware design, the chip named Freescale 16-bit microprocessor MC9S12XEQ512 is selected as the main controller. And the peripheral circuit includes system module of the main chip, the power modules, switch modules, analog modules, the Hall signal module, CAN bus communication module, memory module, SCI communication module and so on. The flowcharts of vehicle control process are written according to control strategy of the pure electric vehicle, and a software program is written based on C language.After the vehicle controller’s design is accomplished, a series of simulation tests and vehicle tests were made to record the data by appropriate equipments. Then the data is analyzed by the PC, and the results demonstrated that the designed vehicle controller could understand the driver’s intentions correctly, allocate the vehicle power reasonably, deal with the data quickly, transfer the data stably, own a strong anti-interference capability and satisfy the requirements of pre-design.