Zoom tracking is an important function in video surveillance, particularly in traffic management and security monitoring. It involves keeping an object of interest in focus during the zoom operation. Zoom tracking is typically achieved by moving the zoom and focus motors in lenses following the so-called “trace curve”, which shows the in-focus motor positions versus the zoom motor positions for a specific object distance. The main task of a zoom tracking approach is to accurately estimate the trace curve for the specified object. Because a proportional integral derivative (PID) controller has historically been considered to be the best controller in the absence of knowledge of the underlying process and its high-quality performance in motor control, in this paper, we propose a novel feedback zoom tracking (FZT) approach based on the geometric trace curve estimation and PID feedback controller. The performance of this approach is compared with existing zoom tracking methods in digital video surveillance. The real-time implementation results obtained on an actual digital video platform indicate that the developed FZT approach not only solves the traditional one-to-many mapping problem without pre-training but also improves the robustness for tracking moving or switching objects which is the key challenge in video surveillance.

Existed in the work of wireless positioning error, the need to suppress NLOS (Non line of sight) transmission problem of positioning the bad influence of the NLOS system model is put forward and the novel geometric positioning model, the introduction of appropriate NLOS channels model to suppress NLOS error, and make full use of the propagation characteristics of derived meet MS (Mobile Station) coordinates equation, with two NLOS paths can only calculate the position of MS, and using only a single base Station can complete the MS positioning, overcome the base Station number too little to pinpoint the flaws of the MS. This paper also gives a method of least squares and maximum likelihood algorithm, using the NLOS paths to improve the positioning accuracy. So as to realize the movement of the MS in NLOS environment position tracking. Through the theoretical analysis and computer simulation analysis, the results show that the positioning method in NLOS environment on the effectiveness and accuracy of the MS positioning.

Abstract. LTE-Advanced is positioned on the higher data rates and a greater system capacity. In order to meet the goal, LTE-Advanced will undoubtedly introduce new wireless technology. The relay technology as key candidate technology of LTE-Advanced system can brings greater coverage and system capacity for residential area. Cooperative relay signal processing methods include amplification forward relay and decoding relay. So, proposed improve the cooperative relay based on the space-time coding, introduced precoding in front of the relay data sent and find out the optimal space-time coding transmission. Through the computer simulation, fully verified the feasibility of improved space-time coding transmission algorithm.

LED Display-Screen is widely used as one of display Terminals to reveal the information in all aspects. With the improvement of living standards, people demand LED display screen to work with the high quality, high speed and high intelligence. The paper presents a method to design LED display-Screen with TMS320F2812 DSP chip of TI, Meanwhile it uses GPRS to communicate with the telephone and the information platform for convenient remote control, it can constitute a large LED display with the CAN bus and so on. The test shows that the system is reasonable, realizable, operated easily, flexible, adaptable to environment, low price, and it is useful in practice after being proved in the practical system. Key words: Display-Screen;TMS320F2812;DSP ;GPRS;

According to the characteristics of vacuum circuit breaker contacts infrared image, put forward a kind of easy hardware implementation of the dynamic threshold Prewitt edge detection and refinement algorithm. Using DSP Builder designed realtime vacuum circuit breaker contacts quality realtime online detection system based on FPGA and used hardware circuit simulation in Matlab and Simulink environment, the simulation results show this design method has many advantages: the edges fine, positioning accuracy high and truly reflect the physical boundary. Realized the vacuum arcing chamber contact wear realtime online detection function, the abrasion of the vacuum arcing chamber contact timely is displayed to monitor staff, and ensured reliable work of the vacuum circuit breaker.