| With the development of electronic and automobile technology, more andmore electrical equipments have been widely used in the automobile. They becomethe effective necessities to assist the automobile drive and improve the safety.Automobile electronics has already worked as economic growth point of the worldautomobile business. In our country, the need is increasing to install electricalequipment on automobile. The electrical equipments make the automobile moreintelligent and bring people more comfort and convenience. People can feel a tasteof high technology and fashion while driving. However, some problems also appear.The wires in automobile increase,so it is more complex to arrange them and theweight of the automobile also increases. In order to solve these problems, thenetwork and the field bus technology has been introduced into automobiles. Amongall the field bus technologies, the CAN bus technology and the LIN bus technologybecome the first choice of many automobile body networks because of their highspeed, low cost, anti-interference, light weight, flexibility and other advantages.According to data types and transmission rate, the automobile network can bedivided into four subnets --- power transmission, safe and chassis control system,automobile body electronic control system, automobile multimedia system andfault diagnosis system. The automobile body network is an important branch of theautomobile network. Automobile body electronic control network mainly refers tothe network established among automobile body electronic control devices whichincludes composite meters, signal and embarkation lamp, set control door locks,seats, air-conditioner system, windows, rear-view mirrors and so on. These systemscan control doors and windows, control air-conditioner and car lighting, remotecontrol door locks open or close and safe-guard door lock system. The purpose ofthis network is to improve the safety and comfort of the drivers, provide theinformation of the automobile body situation, improve the utilization ratio of theconducting wires, make the wire distribution more convenient and simplify thefault diagnosis and repair. At the same time, the network can reduce the connectionof the wires, the weight and cost of manufacture. According to the presentexperimental conditions, components of the network have been chosen. This paper studies the connection of the circuit and the software realization of the automobilebody node in detail. software test and debugging are carried out for every module.At last, functions of the automobile body network system are completely realized.In this paper, the author studies the demand analysis, the springboard of thedesign and the technology requirements of the automobile body network system. Atthe basis of which, the author puts forward the general plan for the design of thesoftware and hardware and finally describes the design of Automobile bodynetwork node controllers in detail. At last, the experiment tried in the real carrealizes the goals of the project after the test of the software and hardware system.Now, summarize every chapter as follows:The first chapter of the paper briefly describes the present developmentconditions of the automobile body network both at home and abroad, discusses thesignificance of the mixed network and lays the theoretical foundation for the designof the general structure. Then the author introduces the general content of the paper,which clarify the main viscera of the research.The second chapter of this paper mainly describes the general design of theautomobile body network system. This chapter discusses the circuit design andnode distribution of the automobile body network system based on thecomprehension and design demand of the automobile body network system. Thenthis chapter describes the design of the software according to its functiondistribution. Finally, this chapter discusses the test design of this network accordingto various experimental models of the automobile body network system. The goalsof the hardware design of the automobile body network system are to realize thehigh-speed process of the data, high-speed reliable communication andanti-interference. The system discussed in the paper mainly uses CAN bus networkand is assisted by CAN/LIN gateway. It adopts the modularity theory and dividesthe automobile body network system into central control module and bottomcontrol module. The central control module includes light group center processmodule, lock group center process module and window group center processmodule. The bottom control module includes light group control module, lockgroup control module and window group control module. The goals of the softwaredesign of the automobile body network system are high stability, easy operationand high readability. It adopts comprehensive design theory and divides the automobile body network system into centralized management and distributedcontrol according to software operation environment. The centralized softwareenvironment is in charge of mainstream communication and information collection.It deals with information and gives orders through the communication unit ofphotoelectric external control, radio frequency equipment external control,response mechanism of external interrupt and serial communication module. Thedistributed software environment is in charge of branch communication, partialdata process and the work of controlled equipments. It deals with informationthrough drive control module, the mechanism of oneself information response,response mechanism of internal interrupt, response mechanism of external interrupt,consecutive communication module and controlled unit.The third chapter of the paper is about the design of the central control moduleof the automobile body network system. It introduces the work process of the dataprocess sub-system from different aspects such as hardware design, softwaredesign and the software design method which the module adopts in data processmethod. The hardware design focuses on the safety and reliability of the networkand analyses the key links of the center control operation. Software design, on onehand, describes software environment based on the principles of blue print, on theother hand, lays a basis for information collection and procession that will bementioned in the following sections, and introduces the general mode of theinformation operation part. As to data procession and software realization of thismodule, this chapter employs syllogism, and enunciates central control processionmethod and realization process of main modules such as lights, locks, windows etc.one by one.The fourth chapter is about the design of the bottom control module of theautomobile body network system. Firstly, this chapter describes the hardwaredesign of each module of the control sub-system including the circuit design,required equipment and relevant functions. Then the author uses an example tointroduce briefly the communication style between central system and sub-systems.Finally, the author describes in detail the information process of each sub-moduleincluding the CAN/LIN gateway from aspects of agreement and communication.The fifth chapter is about the stimulation experiment. The experiment makesthe automobile body network go through multi-aspect tests using USB-to-CAN tool of XingYan company from experimental angles --- stimulation systemrealization, preliminary model construction and imaginary-real test. Therefore, thechapter is a experimental link to identify theory and practice presented in thispaper.Chapter six is the conclusion and prospect. It summarizes and suggestsprospect of the works conducted in this paper, on the basis of discussing theresearch work and questions that need to be considered further.
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