天问一号高分相机星载接口分析与设计

Analysis and design of onboard interface of Tianwen-1 high-resolution camera

为了提高天问一号高分相机的星载接口力热性能,以相机基频和星载温度差为输入开展结构设计。首先,介绍了常见的光学遥感器星载接口的支撑方式,分析了火星探测高分相机对星载接口支撑方式的需求。其次,建立遥感器光学性能与星载支撑接口的对应关系,通过蒙特卡洛分析方法确定接口空间位置相对变化对反射镜的影响,识别出影响整机刚度和热稳定性的接口设计参数。然后建立不同接口方案的分析模型,确定了接口设计的最优方案。最后,通过试验测试获得了该星载接口方案下的整机基频和热稳定性。试验结果表明:采用运动学接口方案,整机一阶基频达到58 Hz,远大于卫星的基频,振动试验前后的传递函数分别为0.196和0.187;同时,在星载接口存在20℃温度差时,相机调焦前后的传递函数分别达到0.173和0.223。基于统计分析的星载接口分析与设计方法能够有效确定接口设计输入,运动学支撑解决了天问一号相机接口的设计难题,设计思路和试验结果对相同类型的载荷接口设计有较强的指导意义。

To improve the mechanical and thermal performance of the onboard interface of Tianwen-1’s high-resolution camera,the structural design is determined by using inputs of the fundamental frequency of the camera and the satellite temperature. First,the onboard interface support requirements of a Mars highresolution camera are analyzed,and common support methods for the onboard interface of an optical remote sensor are introduced. Second,the relationship between the optical performance of the remote sensor and the onboard interface is established. The sensitivity matrix of the spatial position change of the interface to the mirror surface shape is determined by performing a Monte Carlo analysis,and the interface design parameters affecting the stiffness and thermal stability of the entire machine are identified. Then,analysis models of the different interface schemes are established,and the optimal interface design scheme is determined. Finally,the fundamental frequency and stability of the entire machine under the selected onboard interface scheme are determined by conducting experimental tests. The test results show that with this interface scheme,the first-order fundamental frequency of the entire machine reaches 58 Hz,which is considerably higher than that of the satellite,and the MTF before and after the vibration are 0. 196 and0. 187,respectively. Furthermore,when the temperature change in the onboard interface is 20 ℃,the MTF before and after camera focusing are 0. 173 and 0. 223,respectively. This spaceborne interface analysis and design method,based on statistical analysis,can effectively determine the interface design input,and the kinematics support solves the design problem of the interface of Tianwen-1’s astronomical camera. The design ideas and test results have considerable potential in guiding the design of this type of load interface.