Coach Electrical System Design And Analysis Of CAN Bus

With the development and application of computer technology, electronic devices arebeing used more and more popular in the vehicle. The requirements to vehicles inenvironment protection, comfortable, safety and convenience in our country is being higherand higher. Bus, as a kind of public transportation tool, can be seen anywhere around the cityand countryside. In bus industry, no matter that the EuroⅣ taking the place of Euro Ⅲby thepolicy our country will carry out or the vehicle entertainment system and ABS required invehicle level standard, these all represent the application and development of the Intelligentvehicle electronic controller units and electronic control system in vehicle. And it contributesenough to the improvement of whole vehicle performance. Meanwhile, the traditionalanalogue signal control mode by relay or normal switch could not have meet the workrequirement of high-end electronic parts of vehicle’s. Furthermore, it also can not fulfill thevehicle development in the future. Zhongtong Bus Holding Co.,Ltd. has a long history ofmanufacturing large and medium-sized buses for nearly40years. The company concentrateon high-end, mid-priced and low-end buses’ invention and manufacturing. The productionvalue in2010grows over2billion yuan, among which high-end vehicles takes one quarter.The author has worked on the development and application of whole vehicle electricalsystem in Zhongtong bus technical department for many years, and has enough experienceon designing and practical application. Combining with market requirement, he adjusts andimproves designing methods, leads the actual development of this system which has beensuccessfully used in high2or above level vehicles of the company. The system is proved tobe able to satisfy the working and designing requirement of vehicle by mount of relativetests. It is being promoted and applied from high-end to medium-end and low-end vehicles,to improve whole standard of bus using.This system adopts microprocessor inserting technology. The bus network system basedon CAN technology takes the place of traditional point to point control system.Differentfrom the unique units control and conductor jointing way. The main research and work is asfollows:1．By analysing the prophase requirements of whole bus controller area network (CANfor short below). Making Zhongtong high-end buses as a research body, to analyse the worksituation of every electrical parts of the whole vehicle. Analyse the work principle of thestarting system、lighting installation、signal instrument、alarm instrument and vehicleelectrical control system. Analyse the work control mode、electrical current and wirediameter of conducting the electrical current ibid. Supply theory support for control methodand logical relation of each part in CAN bus and the definition of each input and output base pin.2．Analyse the communication way of whole CAN bus and research each meaning ofunits of electric network system(1). Find out the history of CAN bus and using situation of the vehicle. Research theCAN technology, the CAN layering framework and SAE1939Agreement. Analyse the datatransfers in the electric network control system, the definition of data, layering and functionof electric network system. And put forward the definition and demand which has referenceto the CAN bus communication outer circuit:(2). Establish CAN system based on Zhongtong’s high-end and medium-end bus asbasic type. Define instrument display and whole vehicle control system and changeelectromagnetic type meter into stepping motor meter to improve the display veracity andservice life. Combining with the working control method and input/output features of wholevehicle electrical parts, define the input/output base pin used in electrical parts of the wholevehicle. Revise the input and output of some base pins, and establish basic using frameworkof whole vehicle CAN bus system.(3). By adjusting the control method of whole vehicle and assembly structure, assemblethe bus CAN system in Zhongtong high-end vehicle type LCK6125H, then revise anddebug the whole vehicle electrical parts and working parts driven by electric and gas. Makesure that all the work information can display correctly and the system do not break downwhich help establish a stage to extend and apply the CAN system.