星载环形天线可展运动与网状反射面成形精度研究

. Mesh reflector's surface accuracy is a main indicator for the satellite antenna, which is usually formed by the deployment of a ring truss structure. The cable net is originally in a relaxing state, due to deployment motion of the truss, it is tensioned to a expected surface until the truss is locked. Reasonable in orbit deployment dynamic behavior and reflector surface accuracy is directlly related to the space mission of the satellite. Large scale motion of the ring truss usually couples with cable net tension process. Existing researches lack system method, thus deal with the coupled problem individually or by repeated tests. By multibody system theory, this proposal is to investigate the dynamic coupling effects, compatibility of deformation of the deployable truss and flexible cable net. Considering the joints local characteristics, dynamic model of the antenna deploying process is to be built. The mapping function between expected surface deformation field, deploy dynamic quality and antenna topology, design or adjust parameters, deploy control strategy will be discovered. This proposal aims at improving analytical methodology on the active control of deformation field for the flexible body, and also providing technic knowledge to guarantee the reflector's surface accuracy and dynamic quality in the deployment of the antenna.

. 反射面的形面精度是星载天线电性能的重要指标，网状反射面是通过环形可展桁架的展开运动，牵引初始处于松弛状态的柔性索网，张紧至期望形面后锁定形成的；良好的在轨展开动力学性态和反射面的一次精确成形关乎航天任务的成败。而可展桁架的大范围运动与柔性索网的张紧成形存在动态耦合效应，现有研究无法处理两者的协调变形，只能采用独立分析和反复实验的方法。本项目拟基于多体系统理论，研究可展桁架-柔性索网的动态耦合和协调变形机理，计及铰链的局部特征建立环形天线展开过程的动力学模型，分析期望反射面的变形场、展开动力学品质这两个重要评价指标与天线的拓扑构型、初始设计/调整参数、运动控制参数之间的映射关系，并进行参数优化；以期在理论研究方面发展和丰富多体系统理论，形成索网类柔性体的主动变形分析与控制方法，在应用研究方面为环形天线反射面精度与可展运动耦合问题提供分析手段与技术保障。

星载环形天线的展开动力学性态和反射面成形精度关乎航天任务的成败，而针对这种依靠可展桁架的牵引运动导致柔性索网成形且具有超高反射面精度要求的网状天线，目前的设计方法与技术手段已经落后于需求。本项目围绕天线展开特性与形面精度综合保障问题开展了系统研究，主要内容如下：(1)可展桁架-柔性索网的协调变形机理，(2)桁架展开与柔性索网成形过程的多体动力学建模，(3)铰链的局部模型及其对展开过程与成形精度的影响研究，(4)天线展开动力学性态、索网成形精度与特征参数、驱动控制参数的映射关系研究，(5) 天线展开动力学性态和反射面精度保障技术研究。.本项目建立了可展桁架-柔性索网协调变形分析模型，提出了考虑桁架柔性的一体化找形方法，编制了参数化找形设计及网面成形精度分析程序；建立了环形天线动力学分析模型，充分考虑了索网的几何非线性和拓扑多样性，求解了天线在预定展开运动下的驱动方案；测试了铰链刚度特性，完成了铰链建模；分析了展开动力学性态、索网成形精度与特征参数、驱动控制参数的映射关系；最终形成了天线展开性态和反射面精度保障方法和相关设计分析程序。上述研究成果丰富和发展了多体系统理论和索-梁结构分析理论，形成了索网类柔性体主动变形分析和控制方法，为环形天线反射面精度与可展运动耦合问题提供分析手段和技术保障。