基于模态灵敏度分析的网状可展天线形面主动控制机理及实验研究

Considering the requirement for high surface precision of large deployable antenna, surface control problem is to be investigated, especially for deployable antennas consisting of cable mesh. The uniform representation of various surface deformation of antenna under different condition can be presented by fitting surface deformation with its free vibration mode shape. And the contribution factor of each mode shape can be found. The quantitative relationship between control nodes and surface deformation based on single mode shape is to be analized based on analyzing the sensitivity between control nodes and surface deformation, and the control parameter matrix of surface deformation is established. The control parameter matrix is to be optimized by analyzing the relative sensitivity factor of each parameter. A optimized active control method of surface deformation based on mode shape and sensitivity analysis can be obtained based on the contribution factor of each mode shape and the control parameter matrix. Mode test and surface active control test of cable mesh antenna are going to be executed for evaluating control effect by constructing a comprehensive surface precision calculating method. A optimized and reasonable active control method will be put forward by correcting and optimizing the analysis model and control parameters considering the difference between analysis model and test model, which can be pointed out through comparing data of analysis model with data of test model. The core of this work is trying to find the physical essence of surface precision control of cable mesh antenna and explore the forming theory of cable mesh antenna.

瞄准大型可展天线研究的前沿技术，围绕网状可展天线形面精度控制问题，开展天线形面控制机理研究。基于对网状天线的模态分析，研究基于模态振型的多样化天线形面变形拟合方法，获得各阶模态振型对形面变形的贡献因子；采用灵敏度分析方法，研究天线形面变形与控制点的传递函数关系，建立基于模态振型的天线形面主动控制参数矩阵，并采用相对灵敏度系数进行优化；在此基础上，基于各阶模态振型的贡献因子，构建针对形面变形的控制参数矩阵，进而建立基于模态灵敏度分析的网状天线形面主动控制方法；开展天线形面主动控制实验，采用综合形面精度对控制效果进行评价，并依据实验数据对理论模型和控制参数进行修正和优化，获得合理、高效的网状天线形面主动控制方法。本项目通过对网状可展天线形面控制机理的研究，试图揭示网状天线形面精度控制的物理本质，对于探索大型可展天线形面控制机理，提升我国大型可展天线的研制水平具有重要意义。

网状天线形面成形机理及其控制技术是大型网状可展开天线研制的关键技术之一。作为复杂空间张力结构，网状天线形面精度受到张力索张力、反射面张力及变形、零件加工精度及装配误差等多种因素的影响，使得大口径可展开网状天线的研制十分困难。.本课题采用理论分析、数值模拟和实验研究相结合的方法，对网状可展开天线的形面精度控制技术进行了研究，建立了包含天线支撑肋、张力索网以及张力反射膜的“肋－索－膜”系统分析模型，获得了天线形面精度与支撑结构、张力索张力、张力索配置及反射面张力等关键参数的关联关系及变化规律；通过对网状天线各结构参数的灵敏度分析，获得各参数与天线形面变形间的系统结构响应传递函数矩阵。在通过模态分析获得了天线系统模态数据矩阵后，采用多项式拟合方法得到基于模态矩阵的天线形面变形描述，通过求解得到对应天线形面变形的控制参数，实现对天线形面的主动控制，并进行了实验测试和验证；考虑天线反射面信号强度分布不均的影响，建立了基于照度的天线综合形面精度评价指标。在此基础上，开发了天线形态分析及优化设计软件，研制了柔性张力索张力测试装置。.本课题的研究揭示了网状天线形面的成形机理，解决了长期以来困扰科研工作者的天线反射面形状确定问题，为网状天线的结构设计提供了理论依据；本课题开发的天线形态分析及优化软件，实现了径向肋式网状天线结构的快速设计和优化设计，为天线研制提供了有力的支撑；采用天线形面主动控制方法实现了天线形面的快速准确调整，解决了天线形面调整困难的瓶颈问题。