The Research Of Measurement And Control Car Body System CAN Network

In the traditional car body net, large numbers of ECUs make the wires in the automobile increase greatly and occupy a vast amount of spatial. With the development of automobile electronic the traditional car body couldn't be used, CAN bus is a serial communication protocol that be developed to settle the data transport between the ECU and measuring instruments.A kind of distributed vehicle control system is designed to replace the traditional communication net of the bus. With this method can reduce the multiple lines in the bus and accelerate the response speed of the message. With the combination of high speed CAN and low speed CAN it reduces the error rate and the development problems of interfaces effectively.The article analyses the CAN bus protocol in detail and plot out car body module, accepts the CAN bus that the speed less than 125Kbps to connect each nodes. Then it uses J1939 protocal to finish the communication of these nodes. After accepting the data the nodes are able to analyze them and control the facility.The hardware schematic diagrams design chooses the appropriate freescale's MCU MC68HC908GZ16 to design the CAN central module, power module, automobile door and automobile light module and rearview mirror driving circuit. Then simulate the communication of the two nodes in the Code warrior IDE environment. In the aspect of software the thesis chooses C language to accomplish the driving program to make the programe more suitable and practical. Other than these the design also consider the expand function and reserve ports for each circuit.The research has a realistic meaning. Now the bus field is developing very fast with its advanced technologies on abroad.but the native bus market is initial step and most of the producers are engaging in the development of CAN bus. If the CAN bus can be used in the real produce it will give rise to great changes.