Target Image Positioning System Based On DaVinci Platform

With the development of the city and the improvement of living standards, people put forward higher requirements for public security. To this end, many kinds of security devices have been devoted to application, and video surveillance equipment has had a wide range of development. When dealing with security challenges, to obtain the exact locations and field situations of the site is the premise of emergency command. According to the above requirements, this paper proposes a kind of target image positioning system which can get real-time image and position of the target at the same time.In this paper, target positioning system takes target images by an IP camera, the IP camera also calculates target’s3D geographical position using processed sensor data which comes from MCU platform. The target position information can be shown on video screen by OSD technology. And the real-time video is transmitted through network, so control center could get target’s video and location.From the two aspects of target positioning method and principle of network camera, this article analyzes the technical theories used in target positioning technology such as satellite navigation, electronic compass, and laser ranging. Meanwhile, localization algorithm and real-time position information display by OSD based on DaVinci platform are discussed in this paper.In this paper, front-end data acquisition and software development in camera are finished respectively:Firstly, sensor data acquisition platform based on MCU is designed.This platform captures data from sensors include GNSS,electronic compass and laser ranger. Cooperating with remote control keyboard, the platform can send data or instructions to camera module. And at the camera end, RS-485driver is developed under embedded Linux system. The camera uses RS-485interface to receive external data from sensor data acquisition platform.Secondly, to complete the function of target location calculation and system control, target positioning control thread is designed.Thirdly, according to the principle of OSD, OSD thread is realized in network camera work process. With the function of this thread, system can put target information on to the real-time video, including latitude, longitude, azimuth and distance.After prototype system design, the prototype is tested under various situations. The results show that the video is clear, the system has a good positioning effect and can run stably.