Design Of Vehicle Traveling Data Recorder

With the sustained and rapid economic development, China’s continued surge in the number of cars. Even though the transport developed, but also brought a series of questions:frequent traffic accidents and accidents identified difficulties,severe traffic congestion,wasted fuel, urban environmental pollution and so on. In order to effectively solve these problems, countries around the world promoted an intelligent transport system (ITS). Vehicle traveling data recorder is an important part of ITS ,it not only can record the state of cars, but also record video images inside and outside the car, at the same time it can receive GPS signals and transmitted to the control center via the wireless network . Therefore, the development of this multifunctional Vehicle drive recorder has great significance for improving ITS.Based on the functional requirements of the "vehicle drive recorder with national standards" (GB/T19056-2003) and the multifunction expansion demand for ITS, and analyzed the assortment and some insufficiency of the current vehicle traveling data recorder,designed a multi functional vehicle traveling data recorder,which possessed the function of general recorder,and extended other function like video monitoring,GPS,wireless transmission and so on.We designed ARM+DSP architecture for embedded video processing system. Order to simplify development process, the design work into a common control and video processing modules. For common control module, mainly for the hardware circuit design of the CPU control, data storage, analog/digital signal and GPS information acquisition, 3G wireless, SD memory and HPI communication module; Embedded Linux operating system, build a cross development environment, port the Boot loader and Linux kernel , complete platform to build a Linux system; Developed the HPI driver based on this platform ; Finally, gave a main processes of common control module and the part processes of the task flow.For video processing module, we used VMD642 development board and described the design of the development board storage space, power, storage systems,video input and output interface. Video processing module using DSP / BIOS to achieving the capture of video signal, encoding storage and displaying tasks. This paper analyzed the DSP / BIOS real-time operating system and detailed description of the drive design of TVP5150A video capture; Selected H.264 encoder to achieve the encoding of video data and completed the H.264 coding, including the selection, migration and optimization of the H.264 open source;Finally, gave the entire process of the DSP-based video processing module.Finally, some vehicle drive recorder’s features were tested, such as the DSP video data capture and H.264 encoding features. The video compression ratio calculated to 135:1 ,and the further transmission and storage of video data is ready.