| The technology of the ultra-thin mirror is one of the important branches of lightweight optical system. With the improvement of resolution of space optics remote sensing device, its focus and aperture are increasing continually. The ultra-thin reflecting optical system is already defined as the next generation space optical system, domestic and internationally. Active support and control of ultra-thin mirror is the key technology of the ultra lightweight optical system.The development of the key technology for the ultra-lightweight optical system both at home and abroad is tracked in this dissertation. The subject for design method of supporting structure for the ultra-thin mirror is put forward and the research job is supported with National Defensive Fund of Chinese Academy of Sciences. The Design research of support structure for ultra-thin mirror is depicted as following:1. Theoretical research to support the ultra-thin mirror is stated. The basic principle for structure design, little deflection principle of thin plate and axial symmetry crooked theory of round board, is introduced and discussed. The deformation of the mirror, which is supported and fixed in different ways, is computated with the thin plate theory. The equilibrium equation of mirror's shape is founded. The quantity and position of support points is analyzed theoretically.2. The principles and purpose of finite element method (FEM) is stated. Ultra-thin mirror and its support structure is analyzed by means of FEM. The precision standard for structural model is determined.3. The structural FEM model is set up for the ultra-thin mirror with support structure. PV and RMS values of the mirror with horizontal or vertical optical axis are gained. It is indicated that the support structure can meet the precise requirement of the ultra-thin mirror. The material of mirror and its support structure is determined, comparing with the deformation of the mirror with different materials and different support points.4. The quantity of support points is determined, comparing surface figure value from empirical formula with the result from FEM model. Optimization designfor support component is carried on in order to make it more applicable. Single support component is discussed, and the effect to the ultra-thin mirror due to different distance between support points is analyzed. The formula for the distance of support structure and mirror's supported area is deduced.5. The arm's length, angle, position of the support component is adjusted, and then the law of the mirror's surface figure due to the support structure is known. Finally the best support structure is gotten. On this basis, force or displacement load is exerted to find a reasonable adjusting method, in the way the surface figure requirement can be met.6. The support structure of the ultra-thin mirror and an elastic hinge enlarging mechanism is designed. The rationality of the structure is analyzed and multiple of enlarging mechanism is drawn. Measurement of mirror's surface figure is discussed in the dissertation. The experiments are completed. The tested data shows the research method is reasonable and the calculated result is correct.
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