| With the rapid development of the modern automobiles, the lasting increase of electronic devices of automobiles, the traditional wiring harnesses can not satisfy much more complexity of control systems of automobiles. This problem has been resolved by CAN-bus , which has been using widely in automobile electronic control system and is an exclusive automobile LAN as international standard. A multiplex transmission system of automobile window based on CAN-bus, which combines the single-chip microcomputer, has been built. we can transfer all the data only by using the two wiring harnesses, which simples the wiring harnesses, improving the reliability, effectively save the fixing space .First of all, this paper analyzed the developing trend of international automotive network technology and considering its application and development status in China. The basic topology and working theory of the hicle body control system based on the CAN bus is introduced. Technical regulation of CAN Bus network is lucubrated and Data Link Layer and Physical Layer in hierarchy structure of CAN Bus is described. Its basic concept and organizing rules and particularly represents the message,frame format,error style and checking error ability in CAN Bus are simply introduced. CAN controller and transceiver were chosen which are the key chips in the CAN communication. The theories and applications of CAN controller SJA1000 and transceiver PCA82C250 were analyzed in detail.Second, this paper designs the principium schematic diagram and PCB board for the multiplex transmission system of automobile window. It introduces the advantage and disadvantage traditional power supply circuitry and Multiplex Transmission System circuitry of Automobile window. The material experiment project and the data processing circuit card are obtained.Then, a CAN-bus node that based on the CAN-bus 2.0B specification has been designed with the consideration of a bus application. The paper studies the initialization program of SJA1000 and CPU, and the program of transmitting, inception and interruptive. The testing results show that the hardware circuit can run stably with the software program. It realizes the control of Automobile window. At the same time, through analyzing and testing the car window motors' structures, it brings forward the solution of car window anti-nip.Finally, the conclusions of the research were drawn. According as the developing trend of the vehicle electronics field, the improving and perfecting direction of the vehicle body electronic control system based CAN bus were pointed out. |
