Research On Key Techniques Of Photoelectrical Fine Tracking Servo Control With Compound-axis

The research content in this dissertation is developed under the sustentation fund of certain important task, the purpose is solve the application of space optical communication in our nation, especially the problem of information transmission band limitation and information security in the area of national defence and military affairs. Space optical communication has the characteristic of high communication rate, high capacity, high secrecy, low power consumption, small volume, light weight and high ability of anti-jamming, it will become the most potential communication style in the future communication domain, and attracts more and more attention in the world. Based on the need of space optical communication, we constitute the scientific group with Chinese science and technology university and Tsinghua University to develop thorough research and exploitation on space optical communication. The main function of our research team is declined on academic research and system design of ATP (Acquisition. Tracking and Pointing) key technology and laser communication device, especially have gained some significative research fruit, and achieved fair result of prototype laser communication device. This paper aims at the academic research and system design of fine tracking system of ATP system in space optical communication.above all. the concept of space optical communication, key technology, development status and trend is introduced, and the research fruits of Wuhan University laser communication lab is particularly presented, then key technology and development general situation of fine tracking of ATP system has been summed up. which consists of fine tracking detector, precise beam gauche setup, fine tracking image process technology and servo tracking technology.Then two main components of space optical communication ATP system, namely coarse tracking system and fine tracking system, are discussed, including their formation, visual field match and band match. The analysis shows that the bandwidth ratio is more lager, the inhibition residual error ability of coarse tracking is much higher. The influencing factors of ATP fine tracking system bandwidth is analyzed, and provides error distribution for four error sources, on the basis of which, bandwidth compensation correction technology of fine tracking system is discussed, adopting expectation transmission character for optimization compensation to fine tracking system bandwidth, which largely increases open loop and closed loop bandwidth of fine tracking system, stabilization margin meets the challenge, overshoot is small. response speed is rapid, steady and dynamic indicator of fine tracking system is achieved.In succession. traditional steps of fine tracking image processing is elaborated. including facula image filtering. facula image segmentation. facula centroid positioning. facula centroid dynamic system based on wavelet multi-scale kalman filter. on which multi-scale kalman filter, improved centroid algorithm and traditional kalman predictor are used to filter and segment and position the facula centroid. Experimental analysis indicates that standard deviation of facula centroid is largely reduced with this algorithm:poisoning precision increases 80% higher than traditional algorithm.Basic terminology and basic theory of fuzzy control are introduced, disserts on basic structure and design process of fuzzy controller. Then the design method of two kinds of self-adATPing fuzzy controller is disserted in detail, the application of direct self-adATPing fuzzy controller in fine tracking system is take in study, which algorithm adopts self-adATPing predictor and fuzzy controller. Simulation result shows that self-adATPing predictor fuzzy PID controller has better steady performance than traditional fuzzy PID controller. and rapidly adATPs to parameter change of controlled object, approves that it is fair ideal control strategy for fine tracking system.Finally the developed embedded fine tracking control system with the core of FPGA is dissertated in detail, all the technologies are assembled in single chip FPGA. including cameral ink interface technology, image processing technology and tracking and control technology, high bandwidth and high precision embed fine tracking prototype is designed. Experiment test indicates that this system has strong ability to cancel noise and high tracking precision, and meets the general application demand of space optical communication. The tracking bandwidth is up to 200Hz. the reduction ratio to low frequency dithering is more than 80%. the dithering mean square deviation is lower than 1 pixel, poisoning precision is about 1μrad.