Design And Implementation Of Embeded Video Surveillance System Based On Wireless Network

Along with our country precision agriculture of booming development, intelligent continuously push forward the process of agricultural machinery equipment, but agricultural machinery operation information lag and poor timeliness, the organizers and participants receive the information fast, accurate and detailed requirements to meet increasingly prominent problems. Video as the most intuitive information expression, the condition of agricultural machinery in the field can be timely and accurate transfer to the participants in the process of the agricultural machinery operation. General computer as a process platform, there is big, communication hardware operational inconvenience, and the shortcomings of flexibility. The mobility of agricultural machinery and the complexity of the farmland environment often require agricultural machinery of the airborne devices have small size, communication function fully, strong processing ability. With the development of embedded technology, wireless communication technology and the multimedia technology, it provides a new solution in order to design and implementation the devices of the video acquisition, transmission and surveillance for agricultural machinery operation.On the basis of the analysis of the wireless communication technology and video surveillance technology development status and the application in the field of agriculture, the3G wireless network and WiFi wireless network as the transmission medium, combined with the embedded technology, wireless communication technology and the multimedia technology, design and has realized one embedded video surveillance system which based on wireless network and used in agricultural machinery operation field.According to the research background designed the whole hardware project of the embedded video surveillance system based on wireless network, determined the hardware peripheral interface, selected the chip model in the use of the hardware, designed of hardware circuit schematics and PCB. The DM365processor as the core of the hardware control chip, TVP5150video decoding chip realized analog video signal into digital signal. According to the functional need of the system, GL850G chip extended out four USB Host interface, MC703module used as3G module which support the CDMA2000. At the same time, the power module, RJ45Ethernet interface and RS232serial interface all designed in the hardware.The software design and implementation of the embedded video surveillance system based on wireless network design and development was divided into the system software design and implementation and the application program design and implementation.The system software is between the hardware and the application program. The system software design and implementation including the embedded operating system selection, cross compiler development environment building, DM365processor correlative software toolkits installed. Writed the DM365processor bootloader to the hardware development board. Configuration and compile Linux kernel, and developed MC7033G module and WiFi module in embedded Linux environment driver, and realized the3G module accessed to3G network and the WiFi module accessed to WiFi wireless network respectively.In use of modularized software development methods, application program was designed as video image acquisition coding module, video data transmission module and monitoring center three functions of different software module. Low degree of coupling modular design methods improved the system in the application’s expansibility, and also benefited to the application program debugging and maintenance. The H.264video codec technology encoding and decoding video information, according to RTP protocol encapsulated H.264encoded video data. Used multithread programming technology, solved the real-time and multitask processing requirements effectively. UnixDomainSocket socket realized the inter-process communication between different modules. Select query mode network programming method improved the system network service performance.According to the3G wireless network and WiFi wireless network characteristics, carried on the3G wireless network and WiFi wireless network video transmission experimnet, and the experimnet results were analyzed.