The Opto-Mechanical Design Of Aluminum Optical System And Analysis Of Its Thermal Characteristics

Micro-nano satellite has wide application prospect in emergency rescue,military rapid reconnaissance and meteorological timely forecast,and its optical load should be characterized by high lightweight degree,short manufacturing cycle,good temperature adaptability and low cost.Considering the inherent disadvantage of the optical load of traditional ceramic materials,such as glass,on the application of micro-nano satellite system,an aluminum alloy optical system with integration design of structure and function and athermalization design is put forward,which avoids the thermal stress and strain caused by the mismatch of thermal expansion coefficients between different materials,which becomes a new type of micro satellite optical load options due to its high degree of lightweight and good manufacturability.The lack of a comprehensive realization on the influences of the materials,structure and characteristics on the optical system performance result in the experience design of optical athermalization system of aluminum,and the structure deformation law and its suppressing method of the lens body with large expansion coefficient material under the mechanical and thermal load has not been mastered.Based on the demand of micro-nano optical satellite payload,an aluminum optical system and its optical and mechanical design are proposed,and the optimal design with the considerations of lightweight rate,structure stiffness of the lens body,temperature stability and manufacturability is presented.Meanwhile,the comprehensive analysis and forecast of imaging effect is ccompleted by the method of optical and mechanical heat integration analysis.Finally,the lens group is developed through ultra-precision machining and test.The main research contents of this thesis include:(1)The optical system of aluminum material is designed which meets the application requirements of micro-nano satellite,and the effects of ambient temperature on the imaging quality is obtained.The thermal characteristics of the optical system with silicon carbide and invar is analyzed,and the advantages of athermalization design to the optical system is explained.The analysis and formulation of tolerance provide guidance for the following reseach.(2)The structure of optical system is designed and optimized,and the optimization emphases are supporting form,light weight and manufacturability of integrated main mirror.The prediction of the whole machine is realized by the comprehensive analysis of the temperature adaptability and imaging effect with the method of thermal integration.(3)An optical system prototype is manufactured through the single point diamond turning method.The test of shape error detection of aspherical surface figure is carried out with the method of Computer-Generated Hologram,and a clear image is obtained by the wave aberration test and image formation experiment.