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	Structural design of large aperture rectangular mirror for space telescope (EI CONFERENCE) 会议论文 OAI收割 2nd International Conference on Civil Engineering and Transportation, ICCET 2012, October 27, 2012 - October 28, 2012, Guilin, China 作者: Li Z.; Li Z. 收藏 \| 浏览/下载：49/0 \| 提交时间：2013/03/25 Structural design of large aperture mirror is one of the key technologies for space telescope development. To meet the requirements of high stiffness strength and thermal dimensional stability some factors such as support scheme materials selection lightweight design and flexible support design were taken into account. The three supports location of the mirror was determined according to the modal analytical solution. By adjusting the parameters of flexure hinge influences of gravity assembly stress and thermal stress on the mirror were reduced obviously. Finite element analysis (FEA) results indicate that the surface accuracy reach to rms10.2nm and 10.8nm under the gravity along optical axis direction and 5C uniform temperature rise respectively the fundamental frequency of the mirror component is 268Hz. Dynamics test shows that the first order natural frequency is 256Hz which shows an error less than 5% compared to FEA results. (2013) Trans Tech Publications Switzerland.
	Design of motion compensation mechanism of satellite remote sensing camera (EI CONFERENCE) 会议论文 OAI收割 International Symposium on Photoelectronic Detection and Imaging 2011: Space Exploration Technologies and Applications, May 24, 2011 - May 26, 2011, Beijing, China Gu S.; Yan Y.; Xu K.; Jin G. 收藏 \| 浏览/下载：49/0 \| 提交时间：2013/03/25 With the development of aerospace remote sensing technology the ground resolution of remote sensing camera enhances continuously. Since there is relative motion between camera and ground target when taking pictures the target image recorded in recording media is moved and blurred. In order to enhance the imaging quality and resolution of the camera the image motion had to be compensated. In order to abate the effect of image motion to image quality of space camera and improve the resolution of the camera the compensation method of image motion to space camera is researched. First the reason of producing drift angle and adjustment principle are analyzed in this paper. This paper introduce the composition and transmission principle of image motion compensation mechanism. Second the system adopts 80C31 as controller of drift angle and adopts stepping motor for actuators and adopts absolute photoelectric encoder as the drift Angle measuring element. Then the control mathematical model of the image motion compensation mechanism are deduced and it achieve the closed-loop control of the drift angle position. At the last this paper analyses the transmission precision of the mechanism. Through the experiment we measured the actual precision of the image motion compensation mechanism and compared with the theoretical analysis. There are two major contributions in this paper. First the traditional image motion compensation mechanism is big volume and quality heavy. This has not fit for the development trend of space camera miniaturization and lightweight. But if reduce the volume and quality of mechanism it will bring adverse effects for the precision and stiffness of mechanism. For this problem This paper designed a image motion compensation that have some advantages such as small size light weight at the same time high precision stiffness and so on. This image motion compensation can be applicable to the small optics cameras with high resolution. Second the traditional mechanism control need to corrected fitting and iterative for the control formula of mechanism. Only in this way we can get the optimal control mathematical model. This paper has high precision of the control formula derived. It can achieve the high precision control without fitting It also simplify the difficulty of control mathematical model establishment. This paper designed the range of adjusting of image motion compensation mechanism between -5 +5. Based on choosing-5 -4 -3 -2 -1 0 +1 +2 +3 +4 +4 as the expectation value of the imaginary drift angle we get ten groups of the fact data in adjusting drift angle measured. The test results show that the precision of the drift angle control system can be achieved in 1. It can meet the system requirements that the precision of the control system is less than 3' and it can achieve the high-precision image motion compensation. 2011 SPIE.
	Research on lightweight outer baffle for coaxial space camera (EI CONFERENCE) 会议论文 OAI收割 2011 International Conference on Electronic and Mechanical Engineering and Information Technology, EMEIT 2011, August 12, 2011 - August 14, 2011, Harbin, China 作者: Zhang L.; Zhang L. 收藏 \| 浏览/下载：21/0 \| 提交时间：2013/03/25 Stray light is non-imaging light that reach the optical system imaging plane. The non-imaging light can be received by detector if it is not effectively controlled and stray light which directly irradiates on the detector has great influence on the imaging quality. Stray light can be effectively inhibited if the outer baffle of space camera is designed optimally. Carbon fiber composite material is chosen as main material to meet requirements of a coaxial space optical system. The outer baffle should have advantages such as lightweight high stiffness and dimensional stability etc. Using optimization design tools the lightweight outer baffle is designed. And finite element method is used to check the structure. Development and test results show that the outer baffle with a diameter of 620mm and a total length of 1200mm only weighs 7.3kg. And the baffle's natural frequency reaches 88Hz and it can satisfy the requirements of the space camera. 2011 IEEE.
	Fabrication technique of large-scale lightweight SiC space mirror (EI CONFERENCE) 会议论文 OAI收割 3rd International Symposium on Advanced Optical Manufacturing and Testing Technologies, AOMATT 2007: Large Mirrors and Telescopes, July 8, 2007 - July 12, 2007, Chengdu, China 作者: Zhang G.; Zhang G.; Zhang G. 收藏 \| 浏览/下载：28/0 \| 提交时间：2013/03/25 Silicon carbide (SiC) is a new type candidate material for large-scale lightweight space mirror. Its low thermal distortion high stiffness high optical quality and its dimensional stability are better than other traditional optical substrate materials such as ULE Zerodure Beryllium (Be) and so on. In this paper the lightweight silicon carbide space mirror blank was fabricated by reaction sintering. As a space born mirror material silicon carbide must be an optical grade ceramic. So we prepared the silicon carbide green body with gel-casting method. Then some carbon materials were supplemented into the green body which will bring reaction-sintering with silicon in a vacuum furnace during 1500-1600C ultimately the reaction bonded silicon carbide was made. The diameter of SiC space mirror blank we have made is 680mm. If expanding the size of the vacuum furnace bigger mirror blank can be obtained. The test results show that the mechanical and thermal properties of RB-SiC are excellent with bending strength of 350MPa fracture toughness of 4.1 MPa·m1/2 and coefficient of thermal expansion(CET) of 2.6710-6/K. The surface roughness(RMS) could be better than 3nm.