| With the continuous development of space technology,space optical remote sensors have been used more and more.As a key component of the optical system of space optical remote sensor,the mirror accuracy has a direct impact on the imaging quality of the entire remote sensor.In the future,large-caliber mirrors will have an important trend in the development of space optics.However,the increase of mirror aperture will increase the self-weight deformation of the mirror and the thermal deformation caused by temperature changes,and will also increase the design difficulty of the support structure..Therefore,it is necessary to design a reasonable lightweight structure and flexible support structure under the condition of reducing weight as much as possible to ensure that the optical performance of the whole system meets the requirements.The subject focuses on the support technology of large-caliber mirrors for space optical remote sensors to carry out in-depth research on mirrors.The main contents and research results are as follows:(1)Space optical remote sensor large-caliber mirror support technology research:selection from mirror material,main mirror assembly characteristics,mirror support structure characteristics,main mirror assembly relationship,front barrel assembly structure,secondary mirror structure From the perspectives of design,optical system design and assembly process of the main mirror assembly,the overall design and research of the mirror was carried out,which laid the foundation for the lightweight design and support mode research of the main mirror.(2)Research on the lightweight design and support mode of the mirror: the light weight of the main mirror is realized from the aspects of the initial parameters of the mirror structure,the lightweight hole design of the mirror,the lightweight design of the main mirror frame and the design of the limit block.The design is of great significance to the deformation resistance,thermal performance and surface optical quality of the mirror.It is clear that the support mode of the main mirror is tangential injection with 3 points of support structure on the back.The main frame is made of cast titanium alloy.The thermal stress problem mainly relies on the tangential unloading of the main glue spot,which effectively solves the main mirror frame.Material matching problem with SiC primary mirror.(3)Finite element simulation study of the mirror: The modal analysis of the main mirror and the main mirror frame confirms that the main mirror and the main mirror frame meet the fundamental frequency requirements.The modal analysis,the optical axis horizontal gravity condition analysis,the temperature adaptability analysis and the overload analysis areperformed on the main mirror assembly respectively.It is clarified that the fundamental frequency and the main mirror shape of the main mirror assembly meet the design requirements,and the main mirror is framed.After the ambient temperature changes by 4 ° C,the main mirror surface shape is basically the same as the free state.The safety factor of the main mirror assembly in the infinite block and the finite block state also meets the design requirements.(4)Mirror test study: Degassing of the main mirror assembly and the secondary mirror assembly by vacuum deaerator respectively,the purpose of vacuum degassing is achieved;the stress relief vibration test and the secondary mirror web of the main mirror assembly are respectively carried out.The stress relaxation vibration test of the component,the stress relief vibration test of the front barrel assembly and the vibration test of the main mirror assembly,and the mechanism research on the performance degradation of the main mirror assembly were carried out.Through the degradation mechanism research and the simulation of the degradation mechanism,the replacement of the titanium alloy screw was proposed.For the 12.9 grade steel screw,the tightening torque is increased to 70 N.m,which improves the mechanical resistance of the main mirror assembly. |
