空间轻小型离轴三反相机桁架主支撑结构设计

DESIGN OF TRUSSED SUPPORTING STRUCTURE FOR THE LIGHT-SMALL OFF-AXIS THREE-MIRROR REFLECTIVE SPACE CAMERA

为了满足轻小型离轴三反相机精度高、质量小的要求,采用了一种以碳纤维桁架杆结合钛合金安装基板的空间相机主支撑结构。通过分析对比各种空间相机主支撑结构的优缺点,结合本文所述光学系统的特点,确定了次镜安装基板和折叠镜安装基板分开支撑的支撑方式。对初始的主支撑结构进行以一阶频率为优化目标,质量为约束条件的动力学尺寸优化,并对最终的主支撑结构特性进行了有限元分析和试验验证。有限元分析和振动试验表明:在主支撑结构质量不大于4 kg的条件下,所研制的离轴三反相机主支撑结构力学性能指标均满足设计要求,其中一阶频率达到291.4Hz。该离轴三反相机主支撑结构设计方案可以作为其它同型相机结构设计的技术参考。

A trussed supporting structure with carbon fiber trusses and titanium frames was designed to meet the requirements on precision and mass of a light-small off-axis three-mirror reflective space camera. After analyzing the common forms of the supporting structure for space cameras, a method of the supporting structure with the secondary mirror and the folding mirror fixed separately was determined according to the structure characteristics of this optical system. A dynamic size optimization was conducted to lighten the structure and improve the stiffness of this structure. After the size optimization the finite element analysis and vibration experiments were conducted. It shows that the supporting structure could satisfy the requirements on precision and mass of this camera, and the fundamental frequency reaches 291.4Hz under the condition that the mass of this trussed supporting structure is not more than 4Kg. The design scheme of this trussed supporting structure could provide some references to the other light-small space cameras with the same type.