Research On Design And Support Technology Of Huge Mirror For Space High Resolution Infrared Camera

As China's space optical system is more and more widely used to collect military information and civil information,it has extended from the visible spectrum to the infrared spectrum.The longer focal length and the larger field of view of the space infrared optical system requires the corresponding technical support: large diameter mirror design,large-diameter pendulum mirror support structure design,large-size lightweight main support structure design,high-precision truss-type main support structure assembly technology.This dissertation first outlines the military needs and civilian needs of China's long focal length and high resolution space infrared cameras,briefly introduces the international advanced level of space infrared observation system,and compares with our country's spatial infrared information collection capabilities.In order to ensure the overall quality of the ?2020mm reflector while ensuring the overall quality of the ?2020mm reflector,a scheme of supporting the ?2020mm reflector at three points is presentd.The three-point support lightening technology of the ?2020mm reflector is introduced in detail.According to the classic formula group of the mirror design,the initial parameters of the mirror are calculated,and then the maximum amount of displacement of the mirror is estimated according to the theory of material mechanics.Through the comparison between the estimated value and the qualified index,the position of the support point is determined according to the calculation results of the classical formula group,and the specific parameters of the light-weight design of the mirror are determined.Finally,the mirror surface accuracy results under the three-point support is gained through finite element analysis.In order to ensure the surface accuracy of ?2020mm mirror and swing mirror,a new type of hinge structure is proposed,which not only can make the hinge flexible enough but also has sufficient dynamic stiffness.First of all,based on the theory of flexible hinges,the influence of the parameters of the common hinges on the flexibility and rigidity of the hinges is analyzed and the structural parameters of the hinges,which are machinable and adjusted,are also analyzed.Based on the analysis of the sources of flexibility of the tandem hinge mechanism and the parallel hinge mechanism,the form of the new hinge is determined.The three-point support type for the ?2020mm aperture mirror and the large-diameter swing-away mirror were respectively used in the finite element model.The analysis results show that the mirror,which is supported with the new hinge support and the dynamic stiffness of the components meet the requirements.The results of finite element analysis of two kinds of structures and thin-wall cylindrical main support structures with different materials show that the truss-type main support structure is better when the support effect,dynamic stiffness and weight are put forward at the same time.Based on the theory of statically determinate truss and statically indeterminate truss,two statically determinate truss structures mirroring each other are designed.Based on the statically determinate truss,a fully trussed main support structure is designed.Through the finite element analysis of the whole truss-type main support structure and the camera,it is determined that the design requirements can be met.For the entire truss-type main support structure,a reasonable and operational assembly process is designed.Through the process test,it is verified that the triangular truss assembly process leads to the nonuniform adhesive layer,which reduces the cementation strength but still meets the requirements of use.The whole truss-type main support structure passes the mechanical test and the verification test to verify that the main support structure has reached the dynamic stiffness require.