空间激光通信组网反射镜跟踪性能

Tracking Performance of Mirrors in Space Laser Communication Networking

针对空间激光通信组网各网络拓扑节点高度动态、通信链路搭建困难的问题,在现有“一点对多点”组网光学原理基础上,对其反射镜光学天线伺服性能进行研究。通过实验对针对反射镜的基于位置环和基于速度环的两种不同的光闭环控制策略进行对比,结果显示:基于速度环的光闭环策略在跟踪换向时会出现瞬间较大误差抖动,而基于位置环的光闭环策略的跟踪误差在换向时更加平稳,且误差较小。利用Matlab平台进行了基于速度环的光闭环跟踪仿真,仿真得到的跟踪误差与实际跟踪误差基本一致,但并无较大的换向误差。结合低速启动实验,得出结论:该误差来源于速度环较差的低速启动性能,通过增加位置环降低换向跟踪误差的方案适用于轴系谐振频率较高的光机系统。实验还对位置环跟踪下的速度前馈进行了研究,结果表明:前馈增益从0到2递增时,位置跟踪误差先减小后增大,跟踪误差最小值出现在增益值为0.95~1.05附近。

Aiming at the problems of high dynamic topology nodes and difficult communication link construction in space laser communication networking,based on the existing"one point to many points"networking optical principle,the servo performance of its mirror optical antenna is studied.Two different optical closed-loop control strategies based on the position loop and speed loop are compared through experiments.The results show that the optical closed-loop control strategy based on the speed loop will have large instantaneous jitter of tracking and reversing errors,while the optical closed-loop control strategy based on the position loop is more stable and has small error when reversing.The optical closed-loop tracking simulation based on the speed loop is carried out by using the Matlab platform.The tracking error obtained by the simulation is basically consistent with the actual tracking error,but there is no large reversing error.By combining with the low-speed start-up experiment,we concluded that the error comes from the poor low-speed start-up performance of the speed loop,and the scheme of reducing the reversing and tracking errors by adding the position loop is suitable for the optical mechanical system with high resonance frequency of the shafting.The experiment also studied the velocity feedforward of position loop tracking.The results show that when the feedforward gain increases from 0 to 2,the position tracking error first decreases and then increases,and the minimum tracking error appears near the gain value of 0.95-1.05.