离轴三反空间相机与卫星平台的优化连接方式

Optimized connection method of TMA space camera and satellite platform

对于与卫星平台卧式安装的长焦距离轴三反空间相机,由于地面与在轨状态环境条件不同引起平台接口与相机产生温度差,导致相机视轴漂移影响成像质量。为解决此问题,提出了将柔性连接座、刚性连接座和可解锁连接座配合应用的优化连接方式,实现了相机与平台在轨状态3点静定柔性连接,并在运载阶段利用可解锁连接座提高相机基频。利用有限元方法对优化连接方式进行验证,平台接口温度降低15℃引起次镜角度变化为9.62″(安装位置跨距1.2 m),满足光学设计要求;同时运载阶段相机在X、Y、Z三方向频率响应基频分别为120 Hz、120 Hz、110 Hz,与全刚性连接情况相比无明显降低。利用试验工装模拟平台进行温度变化替代试验,平台在温度提高15℃情况下,试验结果与仿真结果相符,且次镜转角实测值与仿真结果最大误差为9%。试验结果说明优化连接方式解决了卫星平台与相机在轨状态温度差引起的视轴漂移的问题,提高了相机的在轨环境适应性。

For long -focus TMA space camera that connect to satellite platform horizontally, the connecting interface temperature difference between satellite platform and space camera is generated due to the alternation of ground test and in-orbit condition, leading to the line-of-sight drift of the space camera which effects imaging quality. In order to solve this problem, the optimized connection method that applying flexible connector, rigid connector and releasable connector cooperatively was proposed. The space camera was flexibly and statically determinate installed on satellite platform in orbit, and the connection stiffness was enhanced by two additional releasable connectors in launching stage so that the fundamental frequency was ensured. The optimized connection method was verified by finite element method, the secondary mirror angular deviation caused by satellite platform temperature decreasing 15℃was 9.62'(the span of installation locations was 1.2 m), which satisfied the optical tolerance. In launching stage, the fundamental frequency of space camera in X, Y, Z directions was 120 Hz, 120 Hz, and 110 Hz, there was no significant decreasing compared with rigid connection. The alternative experiment ofplatform temperature ascending 15℃ was performed via experiment fixture, the test result was consistent with the simulation, the maximum relative error of secondary mirror angular deviation between measurement and simulation was 9%. The results show that the problem of line-of-sight drift caused by satellite platform and space camera temperature difference is solved by optimized connection method, and in-orbit environment adaptability of camera is improved.