Development Of The Automobile Black Box And The Post-analysis System For Traffic Accidents Reappearance

With the development of automobile ability, people pay more attention to the safety of automobile. From the primary absolute mechanism to mechanism assistant with electronic hydraulic pressure, today automobile has become "electronic ware" which based on electronic hydraulic pressure assistant with mechanism. Because of the disturbance of electronic signal, the fault of control hardware, the shortcoming of software and the lapse of electromotor and hydraulic pressure, the responsibility of vehicle accident can not be ascribed to the mistakes of driver simply.To deal with counterclaim of vehicle accident, distinguishing whether it is the fault of automobile itself or the mistakes of driver, American and European manufacturers have developed the recorder of automobile driving state since 90 ages. The order of developing the recorder of automobile driving state is to record the signal of brake pedal, retarder of automobile, gasbag bursting, lock of life belt in collision course. These data are used to judge whether driver has stepped brake pedal, tied life belt , ignited gasbag bursting etc or not, then distinguishing responsibility between automobile manufacturer and driver.The function and the compoing of an advanced automobile black box system is discussed in this paper. It not only can record important data of automobile running roundly and truly, but also includes a dealing software which can help people analyze automobile accident quickly and scientifically. The system is composed of sensor, the circuit of voltage matching, main controller and dealing software.Sensor is very important in detection and auto control domain. Without the high precision measure of sensor, the processing of signal or the display and control of data are unusefulness. This paper presents the sensors used inthe automobile black box system roundly. They include of the position sensor, the speed sensor ,the temperature sensor, the pressure sensor and so on. Because of the hard condition of automobile, this design chooses professional sensors. Through test, these sensors can work reliably in long time which satisfies the request of design target.The core of automobile black box system is its main controller. On survey, all the main controllers of the recorder of automobile driving state made in china use SCM. It conduces the period of sampling being too long, the bit of A/D conversion being small and the precision being low. So here we propose high technology target to make our design meet the advanced level of international. Digital Signal Processor-TMS320F2812 is used in this paper. It is a sort of new high precision Digital signal processor. This text introduces its A/D conversion module , affair manger module, serial communication module and local area network(CAN) control module particularly.The low computer software of this design uses the combination of C language and assembly language. C++ language is applied in the high computer software.The analysis and reappearance of traffic accidents are important means to deal with traffic accidents. This text gives a few basal forms of vehicle collision and the formula of parameters in this collision, then one-dimension and two-dimension models of collision are established.