Research On The Structural Optimization Design Of The Prototype Of Low-light-level And Multi-spectral Imager

Low-light remote sensing is an important part of space optical remote sensing.It can detect targets under low illumination and provide low-light images at night.Now,the increasing demand for scientific observations at night puts forward higher requirements for low-light remote sensing.In this paper,the main structure optimization design of the flight calibration prototype of low-light and multi-spectral imagers is carried out.The camera uses an off-axis three-mirror optical system,which can take advantage of many advantages such as a large field of view and a wide band.The scheme is in line with the development trend of space optical remote sensors.However,the off-axis layout of the reflector proposes higher surface accuracy and position accuracy of the reflector and requires the camera’s main structure to have strong stability and reliability.As a result,it increases the difficulty of structural design.At the same time,in order to better control the launch cost,it is a challenge to pursue a higher degree of lightweight.Therefore,the research work on the optimization design of the main structure of this article is of great significance and is the key to determining the overall performance of the camera.Firstly,the research status of low-light remote sensing imaging and off-axis three-reflection space camera at home and abroad was briefly introduced.And the development trend of off-axis three-reflection space camera was summarized.Then introduced the source of the subject of this article.In addition,the chapter arrangement of this article was stated.Secondly,clarified the requirements of the actual project.And the material,structure and optimization methods of the mirror body and its supporting structure were comprehensively considered.For the first mirror subassembly and the third subassembly,the initial structure design and multi-objective optimization of the reflector body had been completed,and their flexible support structure of the reflector had been designed.For the second mirror subassembly,the comparison of its flexible support schemes and the structural optimization design of the selected schemes were mainly carried out.Of course,the dynamic and static finite element analysis of the mirror assembly showed that they all met the design requirements.Then,the commonly used materials and structural configurations of the main support structure were analyzed.According to the actual situation of the camera,selected the appropriate material and structure configuration,and completed the design of the main support structure.Next,weight reduction was carried out using size optimization.Finally,a simplified complete machine model and simulation analysis were carried out to assess the stability,rigidity and strength of the main structure.An outfield imaging experiment was also carried out to verify the imaging capabilities of the camera.