Hardware Research And Design Vehicle High Definition Video Monitor Dispatch Terminal Based On BDS And 4G Technology

In public transportation field, to realize the real-time status detection and information collection of the vehicles is an important part in Intelligent Transportation System (ITS). Beidou and GPS positioning technology can efficiently obtain the location of the vehicles, and Video Compression Technology (VCT) can effectively collect the running environment of the vehicles. The Intelligent Video Analysis Technology (I VAT) can automatically analyze the information of the obtained video and get the digital data of the vehicle. Mobile Communication Technology (MCT) can transmit the data from the intelligent vehicle terminal to the central server in time to facilitate the big data analysis. The technologies combined with computer technology, form a set of high-technology products in real-time scheduling, video monitoring and positioning, which facilitate the transportation company to get real-time and completely monitoring and schedule the public traffic vehicles. Their application can effectively alleviate the traffic congestion and improve the efficiency and security in public traffic operation.In this thesis, the main purpose is to select A17 with four microprocessors as the principal microprocessor and ARM 7 as a cooperative CPU and form a vehicle high definition (HD) video terminal with dual-core CPU hardware. Through the research of the Beidou (BD) positioning technology, we can realize the real-time positioning, automatic vehicle status announcing, and schedule the public traffic vehicles and so on. Through PoE based power supply and the integrated internal high definition network camera, we can monitor the status of the vehicle with compress and decompress algorithm. The 4G communication technology and WiFi technology can be utilized to realize the real-time communication between the front-end and the background server. Through the design and development of the peripheral interface, the release of the passenger service information, the fare statistics, and also the information acquisition can be obtained.The main contributions of this paper are as follows:1) Design of the system core circuit, which mainly includes the primary and secondary CPU selection, the design of the DDR circuit unit, the design of the Flash circuit unit, the design of clock and reset circuit unit, etc.2) Design of the key system circuit, which mainly includes the design of the vehicle power supply, the design of the BD circuit unit, the design of the 4G communication module circuit unit, and the design of the WiFi module circuit unit.3) Design of the system interface circuit, which includes the design of the USB, Ethernet, RS232, RS485, SATA and the CAN bus.4) Design of the signal processing circuit and practical application with the consideration of the special condition of the vehicle environmental, which includes the design of the audio signal, on-off signal.5) Vehicle HD video terminal test and validation, which includes the test of the hardware interface, such as Beidou module,4G module, and Ethernet interface. Final test and validation of the entire performance is also completed, which includes the environment temperature, electrostatic discharge, radiated spurious emission.