【摘要】：隨著科技的高速發(fā)展,衛(wèi)星作為空地間通信的重要載體,人們對其通信質(zhì)量的要求也隨之提高。相比于傳統(tǒng)的微波通信,衛(wèi)星激光通信作為新型的通信方式,具有頻率高、波長短、方向性佳、波段相對獨立和保密性強等優(yōu)點,故衛(wèi)星激光通信自從誕生之日起就展現(xiàn)出蓬勃的生命力,成為各國研究熱點。在衛(wèi)星激光通信系統(tǒng)中,為了維持良好的通信鏈路,我們必須建立起捕獲、瞄準(zhǔn)和跟蹤(Acquisition、Pointing and Tracking,APT)系統(tǒng),粗瞄控制子系統(tǒng)是APT系統(tǒng)的重要組成部分。本課題以哈爾濱工業(yè)大學(xué)承擔(dān)的“中繼衛(wèi)星星間鏈路技術(shù)”課題為背景,對其粗瞄控制子系統(tǒng)各部分進行深入研究和優(yōu)化,提出假設(shè)并進行了相應(yīng)仿真和實驗進行驗證。掃描捕獲作為APT系統(tǒng)的關(guān)鍵步驟,本文首先對星間光通信的掃描捕獲過程進行說明,闡述了目前常用的掃描捕獲方式,然后通過模型建立和仿真提出優(yōu)化方案,其中包括分別應(yīng)用于單場掃描和多場掃描情形下的優(yōu)化,結(jié)合螺旋和正弦掃描提出新型掃描方案,以及針對粗瞄誤差的不對稱性較高時的掃描方式選擇。其次,針對目前粗瞄反饋環(huán)節(jié)出現(xiàn)的問題進行分析,對反饋測量器件絕對式光電碼盤提出誤差補償?shù)膹?fù)合算法;并對解碼單元板的粗碼譯碼電路進行優(yōu)化改進,以期其適應(yīng)如火箭發(fā)射引起劇烈振動導(dǎo)致的機械結(jié)構(gòu)變形或外太空高低溫等因素造成的各類誤差所帶來的影響。最后,針對粗瞄控制單元的控制算法進行優(yōu)化。指出目前課題中使用的增量式PID算法在實際工作中存在的不足,然后介紹了具有快速響應(yīng)、對參數(shù)變化和擾動不敏感、無需系統(tǒng)的在線辨識和建模的滑模變結(jié)構(gòu)控制,并進行了仿真分析。提出滑模變結(jié)構(gòu)控制器作為增量式PID控制器的備份,在太空中待命工作,以期達到最好的粗瞄控制效果,為后續(xù)精瞄控制系統(tǒng)達到所維持良好通信鏈路提供必要的精度。
[Abstract]:With the rapid development of science and technology, satellite as an important carrier of communication between air and air, people's requirements for communication quality are also raised. Compared with traditional microwave communication, satellite laser communication, as a new communication mode, has the advantages of high frequency, short wavelength, good directivity, relatively independent band and strong confidentiality. Therefore, satellite laser communication has shown vigorous vitality since its birth, and has become a research hotspot in various countries. In the satellite laser communication system, in order to maintain a good communication link, we must establish a capture, aiming and tracking (Acquisition,Pointing and Tracking,APT) system. The coarse aiming control subsystem is an important part of the APT system. Based on the "Intersatellite Link Technology of Relay Satellite" subject of Harbin University of Technology, this paper makes a thorough study and optimization of each part of the coarse pointing control subsystem, and puts forward the hypothesis and carries out corresponding simulation and experiment to verify it. Scanning acquisition is the key step of APT system. Firstly, the scanning acquisition process of inter-satellite optical communication is explained, and the commonly used scanning acquisition method is expounded, and then the optimization scheme is proposed through modeling and simulation. It includes the optimization of single-field scanning and multi-field scanning, the combination of spiral and sinusoidal scanning, and the selection of scanning mode when the coarse scan error is high. Secondly, based on the analysis of the problems existing in the feedback link of coarse sight, a compound algorithm of error compensation is proposed for the absolute photoelectric code plate of feedback measurement device. The coarse-code decoding circuit of the decoded unit board is optimized and improved in order to adapt to the influence of various errors caused by the mechanical structure deformation caused by the intense vibration caused by rocket launch or the high and low temperature in outer space. Finally, the control algorithm of coarse aim control unit is optimized. This paper points out the shortcomings of the incremental PID algorithm used in the present project, and then introduces the sliding mode variable structure control with fast response, insensitive to parameter variation and disturbance, and no need for on-line identification and modeling of the system. Simulation analysis is also carried out. A sliding mode variable structure controller is proposed as the backup of incremental PID controller, which can work on standby in space in order to achieve the best coarse aim control effect and provide the necessary precision for the subsequent fine aiming control system to achieve the good communication link maintained.
【學(xué)位授予單位】：哈爾濱工業(yè)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TN929.1
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本文編號：2381376