热像仪的光轴热稳定性仿真及拓扑优化研究  

Simulation and topological optimization of the thermal stability of the optical axis of the infrared imager

作　　者：李晶[1] 董树林 金宁[1] 杨开宇[1] 杨丹[1] 徐曼[1] 普龙[1] Li Jing;Dong Shulin;Jin Ning;Yang Kaiyu;Yang Dan;Xu Man;Pu Long(Kunming Institute of Physics,Kunming 650223,China)

机构地区：[1]昆明物理研究所,云南昆明650223

出　　处：《红外与激光工程》2024年第1期94-100,共7页Infrared and Laser Engineering

摘　　要：热成像仪由于工作环境较为恶劣,且自身发热量较大,容易导致热像仪光轴发生热偏移,严重影响其瞄准性能。为了提高红外热像仪的光轴热稳定性,以某型热像仪光轴敏感部件——折转镜为主要研究对象,研究其在不同环境温度条件下的光轴变化情况,并通过构建折转镜的有限元仿真模型以及试验测试系统,获得与试验数据一致性较好的有限元模型;以此为基础,采用基于变密度法的拓扑优化仿真技术,以刚度最大化为设计目标,以体积分数为约束,对折转镜座进行了拓扑优化设计。通过试验测试得出,优化设计的折转镜座的光轴高温偏移量由46.1″减小到25.5″,减小了44.7%,折转镜座的光轴低温偏移量由92.9″减小到51.0″,减小了45.1%,极大地提高了折转镜的光轴热稳定性。最后,将优化后的折转镜安装到某型热像仪中进行整机试验测试,热像仪整机的高温光轴偏移量由0.461 mrad减小到0.340 mrad,下降了26.2%,低温光轴偏移量由0.485 mrad减小到0.296 mrad,下降了39.0%,证明了仿真与拓扑优化模型的可行性与有效性,为后续红外热像仪整机的轻量化设计与性能提升奠定了基础。Objective Thermal imaging systems,operating in harsh environments and generating substantial internal heat,are prone to thermal axis deviations,posing a severe threat to their targeting performance.Consequently,the simulation analysis and optimization design of the thermal axis stability for military thermal imaging systems are of paramount importance.This work aims to address these issues and enhance the thermal axis stability of military thermal imaging systems through simulation analysis and optimization design,ensuring accurate targeting performance in adverse operational conditions.Methods In order to enhance the thermal axis stability of the infrared thermal imaging system,this study primarily focuses on a key sensitive component of the system,the optical path folding reflector assembly.The research investigates the variations in the thermal axis under different environmental temperatures.To achieve this,a finite element simulation model for the optical path folding reflector assembly is constructed(Fig.1),and a testing system is established(Fig.5).The simulation model demonstrates a high level of consistency with experimental data.Based on this,a topological optimization simulation technique,utilizing a variable density approach,is employed(Fig.3).The primary design objective is to maximize stiffness,while adhering to volume fraction constraints(Fig.4).Results and Discussions Through experimental test,it was determined that the optimized design of the folding mirror mount resulted in significant improvements in thermal stability.The high-temperature axial displacement was reduced from 46.1"to 25.5",marking a substantial decrease of 44.7%.Likewise,the low-temperature axial displacement decreased from 92.9"to 51.0",indicating a notable reduction of 45.1%(Fig.6).These outcomes underscore the substantial enhancement achieved in the thermal stability of the folding mirror.Subsequently,the optimized folding mirror was integrated into a specific thermal imaging system for comprehensive system-level test.The testi

关 键 词：结构设计 拓扑优化 红外热像仪 折转镜 光轴热稳定性 

分 类 号：V241.02[航空宇航科学与技术—飞行器设计]