Opto-mechanical Structure Research Of The Small Target Simulator

In the ground test,the device that calibrates the star sensor by simulating the star target is the target simulator.With the rapid development of star sensors,target simulators require large fields of view,high precision,and miniaturization to meet development needs.This paper is devoted to the research on small target simulator design method.Through LCOS optical splicing and opto-mechanical structure design to improve the field of view and image pixels and reduce the overall structure volume,the use of opto-mechanical thermal integration analysis to provide optimization and correction methods for the target simulator.The contributions of this paper mainly focus on the following two aspects:（1）The opto-mechanical design of the small target simulator.According to the technical specifications of the target simulator and the optical splicing of LCOS,a collimating optical system with a field of view greater than 22 and a resolution2048×2048 is designed,which the focal length of the optical system is greatly reduced.The MTF curve of the system is 0.4516.The quality of diapoint is good.The optical distortion is less than 0.2%,and the tolerance analysis meets the technical requirements.Through the selection of the mounting method of the fixture and the choice of the opto-mechanical interface,each lens is adjusted and the overall mechanical structure is designed.Through the optimization of the fixed components of the LCOS,the installation accuracy of the LCOS has been improved.（2）Integration analysis of Optical-mechanical-thermal.Based on the designed geometric model,the static analysis and modal analysis has been conducted by Ansys Workbench.The static analysis offset is1.8657e^-5mm,and the minimum natural frequency of modal analysis is 2636.8Hz,which indicats that the strength and stiffness of the mechanical structure meet the technical specifications.The thermal analysis of the target simulator is performed to obtain the thermal response at the actual operating temperature and the deformation of each node.The coordinate data of the lens before and after thermal analysis was solved using the Zernike polynomial method and imported into optical software for optical performance analysis.Combined the analysis and optimization with the experimental verification,the results show that:the overall quality of the small target simulator is reduced to 0.68 Kg,and the actual focal length is greatly reduced to 41mm.In the actual working environment simulation,the MTF is 0.4011 at-10^oC,and the MTF is 0.4322 at 30^oC.Moreover,the energy loss of the interval temperature point map is low,which proves that the structure design of the optical machine is reasonable and has certain temperature adaptability,which satisfies the design requirements.