微纳遥感相机一体式超轻主支撑结构优化设计

Optimized Design of Integrated Ultra-Light Main Supporting Structure for Micro-Nano Remote-Sensing Camera

针对某型号微纳遥感相机超轻质、低功耗、短周期和低成本的要求,设计了一种一体式超轻主支撑结构。从微纳遥感相机的任务需求出发,经过比较后选择钛合金作为主支撑结构的材料,并从质量和功耗两方面考虑选择了桁架式方案。建立了以基频为目标函数的拓扑优化数学模型,推导了目标函数的灵敏度,并通过采用改进的Heaviside密度滤波方法,得到了拓扑结果清晰的主支撑结构最优传力路径。以基频为目标函数建立尺寸的优化数学模型,得到了各部分的最佳设计尺寸,设计完成后的一体式主支撑结构质量为0.6 kg。有限元分析与实验结果表明:一体式主支撑结构能够满足光学系统的公差要求,且基频远高于卫星平台对光学载荷的要求,验证了拓扑优化设计方法和尺寸优化设计方法的正确性以及设计的合理性。

An integrated ultra-light main supporting structure is designed to satisfy the ultra-light, low-power consumption, short-period, and low-cost requirements of a particular micro-nano remote-sensing camera. After comparison with other materials and based on the design requirements, titanium alloy is selected as the research and development focus, and a truss scheme is selected considering mass and power consumption. A mathematical model of topology optimization with fundamental frequency as the objective function is established. In addition, the sensitivity of the objective function is derived, and an improved Heaviside density filter is adopted. As a result, the optimal load path with clear topological results is obtained. Similarly, to obtain the optimal size of each part, a mathematical model of size optimization with fundamental frequency as the objective function is established. Eventually, the mass of the proposed structure is 0.6 kg. The results of finite element analysis and test demonstrate that the integrated main supporting structure can satisfy the tolerance requirement of an optical system and that the fundamental frequency is much higher than the optical load requirement of a satellite platform, which verifies the correctness and rationality of the proposed optimization design.