Lightweight Main Mirror Of Hyperspectral Imager And Topology Optimization Of Supporting Structure

With the continuous development of space technology and demand,space exploration technology has also been more widely used.Among them,spectral imaging technology has been widely used in satellite remote sensing,mineral exploration,land survey,material analysis,etc.due to its advantage of obtaining rich information content.Field,the technology has therefore become the focus of attention in the imaging field.Along with more and more high-precision application requirements,for the highspectral and high-resolution imaging technology,Xi'an Institute of Optics and Precision Mechanics has proposed a large aperture static interference imaging spectrometer(LASIS)design scheme.Among them,the optical mirror is an important part of the spectrometer,and its surface accuracy has a non-negligible effect on the imaging quality of the system.According to the principle of optics,the larger the aperture of the spectrometer reflector,the stronger the light collection ability and the higher the resolution.However,the problems of increasing the weight of the mirror and decreasing the accuracy of the surface shape caused by the increase in aperture also pose severe challenges to the structural design of the spectrometer.The spectrometer reflector in this paper has a caliber of 314 mm,which is currently the largest caliber of the hyperspectrometer in production,so the design of the mirror and its supporting components has also become a top priority.In this paper,the common interference spectrometer is first studied,the factors affecting the imaging quality of the LASIS system are analyzed,and on this basis,the design ideas of the mirror and its components are proposed.Combined with the design ideas,the main factors that affect the accuracy of the mirror shape and the method of evaluating the accuracy of the shape are further studied.The limitations and goals of the mirror design are proposed.The simulation fitting program of the mirror shape based on the Zernike polynomial is written.On this basis,combined with previous ideas,we have completed the preliminary design of the mirror including material selection,mirror back design,support method and lightweight form.In terms of back hole design,this article is based on traditional experience design and topology optimization design.Starting from the aspect,the reflector is designed.The comparison of the design results verifies the advantages of the topology optimization method.Based on the research of the support structure materials,assembly and bonding process,the preliminary geometric structure design of the mirror support assembly was completed.In order to further eliminate the influence of the adhesive layer on the mirror surface shape,the topology optimization of the support structure with flexibility as the goal was proposed The plan completes the design of the mirror support assembly.In order to further verify the mechanical properties of the topology optimization mirror assembly,it improves its reference value for practical engineering problems.This paper firstly compares the static and dynamic aspects of the simulation results and experimental results of the traditionally designed reflector assembly to verify the reliability of the simulation settings.Then using ANSYS analysis software and using the same simulation settings,the topology optimization mirror components were simulated under static weight,and the surface shape fitting program was used to detect the surface shape under the weight of the mirror.In terms of dynamics,overload analysis,harmonic response analysis,and random vibration analysis were performed on the topology-optimized mirror assembly.The results in various aspects prove that the topology optimized mirror assembly designed in this paper has a high degree of light weight and excellent performance,which fully meets the design requirements.