Design Of Support Structure For High Resolution Space Camera

The support structure component connects the space camera and the satellite platform as the joint of the space camera mechanical and thermal environment.It is an important part of the space camera opto-mechanical structure.In the space camera optical system,the installation and positioning requirements of the optical components are strict to avoid factors like errors of the adjustment,external environment affecting the image quality.The space camera structure using the three-mirror off-axis optical system is precise and complex,and sensitive to the space environment,mainly embodied in the severe vibration load during the launch section and the temperature load during the working section in the orbit.The imaging quality and stability requirements of the high-resolution space camera are constantly increasing,and it is especially important to ensure the stability and reliability of the support structure.In this paper,for a high-resolution space camera,the innovative support structure scheme with flexible hinges,including support structure component layout,kinematic constraints,and structural key parameters is adopted,finally achieving high pointing accuracy and thermal adaptability of space cameras,and ensuring the mechanical performance of the space camera.With the help of finite element software,combining the space camera design requirements with dynamic optimization theory,the sensitivity analysis of the support structure and the whole machine is carried out,and the structural parameters are determined along the selected optimization direction.Engineering analysis of structural scheme and space camera is carried out.The analysis results showed that the indicators met the design requirements.The specific research contents are as follows:1.The current development direction of space optical remote sensor is outlined,and the support structure scheme of the main earth observation satellite is introduced.This part also summarizes the characteristics and applicable conditions of various satellite-payload connection modes,and provides guidance for the research of the support structure.2.The problem of accurate positioning of high-resolution space cameras is studied.First,the space camera is assumed to be a rigid body,and the basic principles of kinematic constraints are explained.Then,considering the thermal deformation ofspace camera under temperature change,the space thermal environment and its influence on space camera are introduced,and the relationship between the size variation of optical system and the difference in temperature of the installation position is analyzed.Finally,combined the kinematics principle with the influence of temperature load,a preliminary layout scheme of support structure is proposed.3.According to the design requirements of high-resolution space camera,the thermal adaptability design of space camera is carried out.Considering the deformation of the space camera under temperature load and the structural characteristics of the optical system,the release direction of the space camera is determined.Combining the results of thermal adaptability design and the mechanical performance requirements of the space camera,a flexible support structure scheme is proposed.By adopting the series flexible hinge scheme,the thermal deformation unloading ability is obtained and the influence of the gap between the hinges of kinematic support structure on the pointing accuracy and the fundamental frequency of the whole machine is reduced.4.The structural dynamics optimization theory and sensitivity analysis theory are introduced,and the theory is applied to the optimization of space camera support structure.Combining the theory with experience,the optimization parameters and optimization targets are determined.The sensitivity analysis of the key parameters of the support structure is carried out by using software such as Isight,and the optimization direction is determined.The relationship between the some performances and the optimization parameters is organized,and the parameters of the support structure is determined.5.For the design requirements and actual working conditions of the support structure,the finite element model of the support structure and the high-resolution space camera was established by using the finite element software MSC.Patran/Nastran.The analysis of the support structure and the whole machine are operated,including statics,dynamics and thermal stability.The analysis results show that the fundamental frequency and dynamic response of the high-resolution space camera are good.Under the temperature load,the support structure releases the degrees of freedom along the design direction.And all indicators meet the design requirements.