Study On The Primary Lens Expansion Technology Of Space Thin Film Diffraction Telescope

Diffraction imaging technique which can realize space deployment of a large aperture,lightweight,low cost,deployable and high resolution telescope,is an important direction for the development of optical earth observation satellites.In view of the limited space of launch vehicle,the Space folding technology is the key technology to solve the development and launch of the large aperture space telescope.This paper mainly focuses on the research of the development of the primary lens of the space thin film diffraction telescope.The research contents include the following aspects.1.This paper details the development status of the diffraction imaging technology at home and abroad,focusing on the development of the United States in the study of diffraction imaging system and the progress of the research on the theory of diffraction imaging in China.At last,this paper expounds the necessity of the research on the primary lens expansion technique of the diffractive telescope.2.The study of diffractive telescope imaging system,including diffractive optical elements,dispersion properties of diffractive optical elements and tolerance characteristic of diffraction imaging system.The results show that: the diffraction lens using thin film material have the advantages of small size,light weight,high resolution and smart design;Diffraction imaging system can use the theory of Schupmann proposed to achieve wide spectral imaging;Compared with the reflective imaging system,the diffraction imaging system has a loose tolerance requirement,which is conducive to reduce the design,processing and transmission costs.3.This paper puts forward the specifications of 10 meter diameter thin film diffraction telescope primary lens.With the idea of modular design,the structure can be divided into support structure,drive structure,locking structure and positioning structure,respectively.Finally,the structure is modeled using SolidWorks,and finite element analysis software ANSYS is used to analyze and evaluate the key parts of the structure.4.at last,the virtual prototype of the primary lens deployable structure are established,while kinematics and dynamics simulation is implemented using ADAMS software.The kinematic analysis of the driving structure shows that the design of drive structure can guarantee the angle accuracy of the deployable structure;the rationality of the design of the locking structure is verified by the dynamic simulation.We can also obtain the elastic deformation nephogram of the Shrapnel in the locking process,which can guide us to improve the structure;the simplified model is adopted in the simulation of deployable structure system,which proves the rationality of the principle of folding expansion design.The application of virtual prototyping technology is to find the problems in the structure design,and put forward reasonable suggestions for the structure design.