基于梯度优化的FAST反射面调节及接收比的研究  

Implementation Model of Gradient Optimization Algorithm for FAST Reflector Adjustment and Receiving Ratio

作　　者：郭学俊 裴智明 靳谦诚 张迪 李雪 GUO Xuejun;PEI Zhiming;JIN Qiancheng;ZHANG Di;LI Xue(College of Data Science,Taiyuan University of Technology,Taiyuan 030024,China;College of Mechanical and Vehicle Engineering,Taiyuan University of Technology,Taiyuan 030024,China;College of Water Resource Science and Engineering,Taiyuan University of Technology,Taiyuan 030024,China)

机构地区：[1]太原理工大学大数据学院,太原030024 [2]太原理工大学机械与运载工程学院,太原030024 [3]太原理工大学水利科学与工程学院,太原030024

出　　处：《太原理工大学学报》2022年第4期744-750,共7页Journal of Taiyuan University of Technology

基　　金：国家自然科学基金资助项目(11305115)。

摘　　要：针对FAST目前主索节点及各促动器位置自主调节模型仅局限于对点的模型,缺少动态变化的调节模型的问题,在FAST球面望远镜满足最佳接收比的情况下,采用非线性规划和梯度下降寻优算法,利用梯度优化得出理想抛物面与主索节点之间的距离,以反射面板调节限制为约束条件,得到主索节点改变后的坐标,根据FAST的4400块三角形反射面板,2226个主索节点建立了FAST反射面变形的网面调整策略模型,并通过非线性优化算法探讨了望远镜变形后的具体位置;同时基于费马原理,模拟三维空间中电磁波反射情况,进行馈源舱接收比的计算,对建立的模型进行了模型观测和检验。检验结果表明,接收比为1.43%,调整抛物面照明区域内反射面板数为1295块,成功反射信号到达馈源舱的反射面板数量为1295,比率为100%.经检验,在本模型当中得到的均方误差(Mean square)为0.3089,说明FAST可以实现在某射波频段自如进行自主面调节的工作,并获得较高的接受比。In view of the fact that the current automatic position adjustment model of Fivehundred-meter Aperture Spherical radio Telescope(FAST)main cable nodes and actuators is only limited to point-to-point model and lacks the establishment of dynamic change adjustment process,under the condition that the FAST Spherical Telescope meets the optimal reception ratio,aiming at 4400 triangular reflection panels of FAST,nonlinear programming and gradient descent optimization algorithm were used to establish the network adjustment strategy model of FAST reflector deformation for 2226 main cable nodes of FAST.The specific position of the telescope after deformation was obtained by using the nonlinear optimization algorithm.According to the Fermat principle,the electromagnetic wave reflection in three-dimensional space was simulated,and the receiving ratio of the feed cabin was calculated.The model was observed and tested.The experimental results show that the receiving ratio is 1.43%,the number of reflection panels in the paraboloid illumination area is adjusted to 1295,and the number of reflection panels that successfully reflect the signal to the feed cabin is 1295,with a ratio of 100%.After testing,the mean square obtained in this model is 0.3089,which shows that FAST can freely adjust the autonomous surface in a certain radio frequency band and obtain a high acceptance ratio.

关 键 词：FAST主动反射面 理想抛物面 坐标变换 梯度下降寻优算法 费马原理 GRASP仿真 

分 类 号：P162[天文地球—天文学]