The Research Of Vehicle Data Recorder Based On CAN Bus System

Vehicle data recorder which also named "black box", is a kind of electronic device which can record parameters such as speed, time, mileage to the vehicle and so on, all of these information can be saved in a safety space and can be outputted by special port. For every time in detail, the multi-function vehicle driving recorder records start time, mileage, driving time, the highest speed and the time the vehicle keeps on. It gives a voice to alarm when the driver exceeds the limited speed; information of vehicle which would be troubled in an accident will be saved before the accident, and could be moved away by USB storage for analysis. The advanced recorder has the capability to deliver information by GSM or GPRS in long-range, and GPS (Global Position System) also be used. According to the vehicle information, the apartment of traffic management makes a much more convenient way to carry on a valid management to the vehicle, so this can significantly lower the occurrence of accident.CAN is a kind of serial multi-hosts communication agreement with high baud rate and high anti-electromagnetism interference, and can set out rarely each mistake. For its outstanding performance, CAN has already been applied in numerous realms extensively, such as vehicle, the industry automation, aerospace, medical instrument, construction and environment control etc.This text analyzed the characteristics of CAN bus system, studied a current situation of the data delivering and saving technique. The author's mainly work as follows:1. Analyzed the characteristics of the CAN bus system, make sure that the most important part of the data delivering is the CAN bus node, then carry on CAN node controller a design from the software and hardware, first we should confirm the classification of bus physical layer and different delivering mode; Secondly, software design include the CAN bus agreement application and realization of data saving is needed. Even the whole system damages, the data still can be read if the memory chip is intact.2. According to design strategy for hardware, single chip computer C8051F020 is appropriate to be processor, and with SJA1000 and TJA1050 together the Vehicle driving data recorder will be built up. Establishing a frame format by CAN and improve the efficiency of data recording.3. The thesis adds USB data saving and video alarm in the original foundation. Unifies with the CAN bus technique, Vehicle driving data recorder has a good application prospect because of its expansibility and transplantation, Transferring the data to the PC by USB can carry out data analysis and basically satisfied the original design. Even though, parts of functions such as GPS, GSM long range management, amusement system etc. need much more work to consummate.