在轨维修后端模块接口机构的研究

Research on interface mechanism of back-end module for on-orbit maintenance

在轨维修可以大大的延长空间科学仪器的使用寿命,节省大量的经济成本。为了实现空间望远镜后端模块的在轨操作和更换,设计了一套与之对应的接口机构,能够解决在轨快速定位与安装。根据321运动学定位准则,详细介绍了该接口机构的内部组成和工作原理;然后把该接口机构与后端模块进行组件级有限元仿真,仿真结果表明一阶模态远高于整机基频可以有效地避免发射时候的共振;设计了一套平面内的工装来模拟后端模块,利用等效质量法对整个机构进行重力卸载;搭建实验平台,利用激光跟踪仪来测量整个后端模块的重复定位安装精度,实验数据表明,X,Y,Z 3个方向的重复平移定位误差分别为±5.58μm,±3.24μm及±3.63μm,优于总体指标±10μm;热实验结果表明整个机构可以完全释放由于温度变化产生的形变,具有很高的热稳定性;使入射光线和靶面的相对位置持续稳定,保证了较高的成像质量。为其他空间在轨维护装置提供强有力的参考价值。

On-orbit maintenance can significantly extend the service life of space science instruments, thus reducing economic costs. In order to realize on-orbit operation and replace the back-end module of a space telescope, a set of corresponding interface mechanisms was designed, which can solve the problem of on-orbit rapid positioning and installation. According to the 321 kinematic positioning criteria, the internal composition and working principle of the interface mechanism were introduced in detail. Then, the interface mechanism and back-end module were simulated at the component level. The simulation results show that the first-order mode is much higher than the fundamental frequency of the whole machine, which can prevent resonance when launching. A set of in-plane tooling was designed to simulate the back-end module, and the gravity unloading of the whole mechanism was carried out using the equivalent mass method. A laser tracker was used to measure the repetitive positioning accuracy of the whole back-end module. The experimental data show that the repetitive translation positioning errors of X, Y, Z in three directions are ±5.58 μm, ±3.24 μm and ±3.63 μm respectively, which are higher than the overall index of ±10 μm. The thermal experimental results show that the whole mechanism can completely release the deformation caused by temperature change, and has high thermal stability. The relative position of the incident light and target surface is stable, and the imaging quality is high, which provides a strong reference value for on-orbit maintenance devices in outer space.