Research And Design Of Vehicle Travelling Data Recorder Mainframe Based On Vehicle Network

As the rapid development of transportation, car has become one of important transporting tools and the total amount of them increases continuously. Many traffic accidents happened because of absence of travelling data recording, and then the responsibility could not be clarified. Vehicle Travelling Data Recorder (VTDR) is an especial electronic equipment, which can record and store the data of velocity, date, distance and other information of vehicle then output them through the interfaces. Through the monitoring of real time state of car, the illogical behavior of dirvers can be restricted and the recorded data can be used as a proof for analyzing of traffic accident. The health of vehicle also can be checked. Meanwhile, some functions such as electronic watches, breakdown diagnosing, alarm, GPS, GIS, can also be integrated in it.According to the national standard of VTDR (GB/T19056-2003), an Vehicle Travelling Data Recorder consists of the mainframe part and managment software part on PC. This thesis focus on the reseaching and designing of the mainframe of VTDR. At first, the domestic and foreign situation of VTDR is analysed and then the emphases and framework of thesis are expatiated. The basic framework of VTDR is introduced. It consists of the central processing module, data collecting module, data storing module, USB host module, CAN-BUS module, RS232 module, clock module, display module, IC card module, keyboard interface module, data printing module and power module. The chips of each module are introduced, so are the realized circuits. The DSP+CPLD framework is employed in this system, so it is easy to extend and upgrade and the complexity of circuit can be reduced. And then the sofeware designing of VTDR is expatiated. The development flow and environment of DSP system is introduced after that, which includes development enviorment and program language, memory file, command file. Then the flow of main loop is introduced. The software designing of USB host is an important part, and then software flows of hardware modules are given. At last, some useful measures to avoid the disturbance of PCB and hardware are introduced, so are the test methods. At the end, some parts of VTDR which should be upgraded and improved are expatiated.