Wiper Motor Control System Design Based On LIN And USB Bus

According to the rapid development in electronic technology, a number of electronic equipments are applied into the vehicle domain, which leads to the speedy increase in the automotive body wiring. The traditional lining methods are far below the satisfaction, thus, promoting the development in automotive bus technology. A local interconnect filed bus network, LIN, emerges as the times require, in this background. LIN bus is specified as low cost, high reliability, mostly used in the automotive body control unit that requests little in the transfer speed, including the wiper motor control.Faw-Volkswagen Company holds an automatic evaluation system for the wiping quality of the windscreen wiper. This dissertation is aimed to add the wiper motor controlled by LIN bus into this system, and the new system can control the LIN wiper motor through the computer. MCU MC9S12D64 is chosen as the kernel to constitute the embedded system, and LIN bus protocol is realized in firmware type, to achieve the purpose of controlling LIN wiper motor. The embedded system adopts USB bus interface to communicate with the computer. In the computer side, USB driver and communication application program are programmed. The application operation interface of new evaluation system is completed at last, seamlessly combining the LIN wiper motor control.First, this thesis introduces the newest basic knowledge of LIN and USB bus protocol, which is the basis of the whole system design. Second, the hardware circuit design of embedded system is described in details, including the interface circuit of LIN interface chip MC33661 and USB interface chip PDIUSBD12, connecting with the MCU. Furthermore, the design experience in EMC is summarized up in this system's PCB fabrication, to improve the reliability. Third, LIN and USB firmware are realized in MCU through embedded C, based on modularization and hierarchy design thinking. Last, in the computer side, the programming method and experience of WDM type USB driver are detailedly explicated, also the process in programming the USB device communication application using VC. The USB device read/write function are packaged in DLL style, and it is called in the application program, to append the LIN wiper motor control. The DLL called in VB is also programmed by VC.This dissertation mainly completes the firmware design of LIN and USB bus in the embedded system part, realizing LIN bus protocol and applying USB bus technology into industry real time control. And in the computer part, this dissertation basically accomplishes the programming of USB driver and application interface, achieving human operation and perfecting test function. Through industry field debugging, the effect is so good that the system can be put into daily work.The next step is to unite the automotive rainfall sensor to the LIN bus directly, as a LIN node like wiper motor, to come true the autocontrol of wiper motor.