星载光电跟瞄转台动态特性分析  

Dynamic Characteristics Analysis of Space Electro-optical Tracking and Pointing Turntable

作　　者：彭加力 阮萍[1,3] 谢友金[1,3] 李治国[1,3] 王佳浩 韩璟宇[1,2,3] PENG Jiali;RUAN Ping;XIE Youjin;LI Zhiguo;WANG Jiahao;HAN Jingyu(Xi’an Institute of Optics and Precision Mechanics,Chinese Academy of Sciences,Xi'an 710119,China;University of Chinese Academy of Sciences,Beijing 100049,China;Key Laboratory of Space Precision Measurement Technology,Chinese Academy of Sciences,Xi'an 710119,China)

机构地区：[1]中国科学院西安光学精密机械研究所,西安710119 [2]中国科学院大学,北京100049 [3]中国科学院空间精密测量技术重点实验室,西安710119

出　　处：《光子学报》2023年第7期193-207,共15页Acta Photonica Sinica

基　　金：中国科学院青年创新促进会项目(No.2018441)。

摘　　要：针对目前利用有限元方法分析星载光电跟瞄转台动态特性时存在的建模失真问题,提出使用广义弹簧单元对轴承和锁紧机构等效建模,并通过定义模态阻尼比,精确模拟转台的固有频率及响应特性。通过理论计算和基于模态试验数据的参数辨识,确定各等效单元刚度;通过基于扫频试验数据的参数辨识,确定结构模态阻尼。基于建立的等效有限元模型进行仿真分析,模态分析中前6阶固有频率与试验结果的最大偏差为5.1%,谐响应分析中X、Y、Z三个主方向的最大响应与试验结果的最大偏差为3.2%,固有频率与响应一致性良好,均在允许的误差范围内。说明使用广义弹簧单元对轴承和锁紧机构进行等效建模,通过模态和扫频试验数据确定转台刚度和阻尼特性是可行的,对同类型转台的建模仿真有一定借鉴作用。The space electro-optical tracking and pointing turntable is a kind of space photoelectric payload,which is used to realize the stability of the optical axis and the tracking of the target in the space environment.In the process of launching,the turntable must endure many harsh mechanical environments such as vibration and shock,therefore,its dynamic characteristics directly determine the reliability of the turntable.When we use finite element method to analyze the dynamic characteristics,a finite element model that can accurately reflect the stiffness and damping characteristics of the turntable is the key to the analysis.The stiffness of the connected parts in the turntable,such as bearings and locking devices,has a great influence on the stiffness characteristics of the overall structure.In the current research,there is a distortion problem in the finite element modeling of bearings and locking devices.Aiming at this problem,this paper proposes an equivalent modeling method for bearing and locking devices by using generalized spring elements(bushing),which represents the behavior of a flexible connection or joint that allows translational and rotational movement.The translational degrees of freedom allow movement along the X,Y,and Z axes,representing the linear displacements in those directions,the rotational degrees of freedom allow rotation around the X,Y,and Z axes.We analyze the bearings and locking devices under dynamic load,establish their mechanical models,and define the significance of the Bushing elements stiffness matrix parameters.Then we simplify the structure of turntable,complete the equivalent modeling for shafting and locking devices by using Bushing elements,establish the finite element model of the turntable.Afterwards,we calculate a partial of bearing stiffness parameters based on Hertz contact theory.The remaining bearing stiffness parameters and all locking devices stiffness parameters that can not be theoretically calculated are obtained by parameter identification based on modal test dat

关 键 词：精密仪器与机械 动态特性 等效建模 星载光电跟瞄转台 刚度与阻尼 固有频率 振动响应 有限元分析 

分 类 号：TH123[机械工程—机械设计及理论]