Lightweight And Optimization Design And Research For The Opto-Mechanical Structure Of Off-Axis Space Camera

Off-axis three-mirror astigmatism system is widely used in space optical remote sensor because of its advantages of long focal length,large field of view and wide band.With the development of space technology,high resolution,wide coverage has become a major development trend of space cameras,followed by the aperture and total mass of the camera is increasing.At the same time,light and small remote sensing satellites present a higher requirement on weight and performance of space on-board equipment,which results in the lightweight and optimization design for space cameras,especially large-aperture off-axis camera is facing a great challenge.Based on the structural characteristics of the space camera,the lightweight off-axis camera structure is designed and optimized to meet the requirements of lighter and better performance of the light-weight satel ite camera.Firstly,the development and trend of space cameras at home and abroad were briefly introduced from the aspects of materials and support forms of mirrors,optical-mechanical structure of cameras including supporting structure between primary mirror and secondary mirror.Two kinds of optimization methods commonly used in optical structure optimization were introduced.They are topology optimization method and integrated optimization technique.And then the main content and significance of this research were elucidated.Secondly,the primary mirror,secondary mirror and tertiary mirror were lightweight designed.The back-center support way was proposed for the space mirror.By adopting this support method for each mirror in the camera,not only the design difficulty of the supporting structure but also the total mass of the mirror and the supporting structure was reduced.The optimization design of the reflector is carried out by using the integrated optimization technique.By using integrated optimization technique,the mass of the mirror is reduced and the surface shape precision of the mirror is improved further.The static and dynamic performances of the mirror assembly were simulated and analyzed to verify the reliability of the design results.The results show that the dynamic and static mechanical properties of the mirror assemblies meet the design requirements.Then,the primary supporting structure of the camera was designed with lightweight optimization.The back pedestal which is the massive assembly of supporting structure was optimized by topological optimization method to reduce the quality of the primary supporting structure,and the truss system was optimized by the integrated optimization technique.The dynamic and static stiffness of t he truss structure was improved by the layout optimization and the section optimization.The static and dynamic simulations were carried out to test the reliability of the main support structure.The results show that the dynamic and static stiffness of the structure meet the design requirements.Finally,the supporting characteristics of the space Si C mirror supported by rear in centre were studied with the ?500mm Si C circular mirror as an example.The main structural parameters which will affect the performance of the mirror were analyzed in this paper,which provides ideas and references for the research on space mirrors supported by rear in centre.