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Structural design of primary mirror subassembly for space telescope (EI CONFERENCE) 会议论文  OAI收割
2nd International Conference on Mechatronics and Applied Mechanics, ICMAM 2012, December 8, 2012 - December 9, 2012, Taiwan
作者:  Xu H.
收藏  |  浏览/下载：67/0  |  提交时间：2013/03/25
In order to design a large aperture primary mirror with the diameter of 1150 mm  the parameters impacting on gravity deformation of the mirror were analyzed and discussed in detail  including material selection  diameter-thickness ratio  the number of the support points  location selection and lightweight structure  etc. A novel space mirror structure system was put forward  and its back was opened and supported by six points on back. The dynamic and static and thermal characteristics were analyzed based on the finite element method. Analysis results showed the surface figure accuracy reached to RMS 14.5nm under the action of gravity load along the optical axis direction and the first-order natural frequency was 214Hz which met to the designed indexes requirements. (2013) Trans Tech Publications  Switzerland.  
Engineering analysis and research on connection plate of vehicle radar antenna pedestal (EI CONFERENCE) 会议论文  OAI收割
3rd International Conference on Frontiers of Manufacturing and Design Science, ICFMD 2012, December 11, 2012 - December 13, 2012, Hong kong
作者:  Sun H.;  Sun H.;  Li Y.;  Li Y.;  Li Y.
收藏  |  浏览/下载：33/0  |  提交时间：2013/03/25
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.  
Stray light analysis of solar photoelectric detection system on space target (EI CONFERENCE) 会议论文  OAI收割
2012 International Conference on Intelligent System and Applied Material, GSAM 2012, January 13, 2012 - January 15, 2012, Taiyuan, Shanxi, China
Li L.-Y.; Wang Y.-F.; San X.-G.
收藏  |  浏览/下载：148/0  |  提交时间：2013/03/25
Most conventional spacious solar photoelectric detection systems suffer from unexpected stray light. This paper demonstrates the effects on photoelectric detection system bring out by stray light. On this foundation  build up evaluation index of stray light system  to search the reasonable programme to eliminating stray light. A detailed telescope system geometry model was created  and scatter models were create for telescope and enclosure components. By the means of designing the structure of main baffle  baffle vane and the coating technology. In order to verify the prosperity of structure that designed  we utilizes software to analysis opto-mechanical model. we utilizes software to analysis opto-mechanical model. The simulations show that point source transmittance of the system is thus reduced by up to two orders of magnitude between 10-8 and 10-10. Meanwhile  the experiment obtains clean detection data which satisfies the system requirements. Stray light has been suppressed effectually  and so measurement precision was improved from detection graphics. (2012) Trans Tech Publications.  
Study on ultra-light secondary baffle for coaxial two-mirror telescope (EI CONFERENCE) 会议论文  OAI收割
2012 9th IEEE International Conference on Mechatronics and Automation, ICMA 2012, August 5, 2012 - August 8, 2012, Chengdu, China
作者:  Zhang L.;  Zhang L.
收藏  |  浏览/下载：70/0  |  提交时间：2013/03/25
The coaxial two-mirror telescope consists of two mirrors facing each other. Classical two-mirror arrangements are Gregorian and Cassegrain. These systems are usually applied to space telescopes and often have optical baffles to prevent stray light from entering the focal plane. The optical baffles consist of concentric rings suspended between the secondary and the primary mirror. The secondary baffle for a large two-mirror optical system is designed and analyzed in this paper. According to mission of a telescope  the structure should have high stiffness and high reliability and light weight. Compared with invar  aluminum alloy and titanium alloy  carbon fiber composite is currently the best material in terms of weight-to-strength ratio. It also has advantages of high temperature tolerance and low thermal expansion. So carbon fiber composite is chosen as material to meet requirements of the coaxial telescope. In this paper  optimization method based on finite element analysis (FEA) is used for design the secondary baffle. Minimum weight of the baffle is chosen as an objective function. Thicknesses of former tube and vanes are chosen as variables. Analysis results show that the designed secondary baffle has maximum diameter of 180mm  total length of 120mm and weighs 142g. And its fundamental frequency reaches 651Hz. Therefore the baffle has many advantages  such as ultra-light weight  high stiffness and dimensional stability  etc. The optimization method and the baffle design can be helpful to other coaxial telescopes  such as Cassegrain  Gregorian and their subdivisions. 2012 IEEE.  
An engineering analysis and research on center frame structure using casting of vehicle radar antenna pedestal (EI CONFERENCE) 会议论文  OAI收割
2012 International Conference on Industrial Design and Mechanical Power, ICIDMP 2012, July 10, 2012 - July 11, 2012, Huangshan, China
作者:  Li Y.;  Liu W.;  Li Y.;  Li Y.;  Li Y.
收藏  |  浏览/下载：29/0  |  提交时间：2013/03/25
Study of horizontal shafting with spherical four-way structure (EI CONFERENCE) 会议论文  OAI收割
2012 International Conference on Optoelectronics and Microelectronics, ICOM 2012, August 23, 2012 - August 25, 2012, Changchun, China
作者:  Yang L.;  Yang L.
收藏  |  浏览/下载：35/0  |  提交时间：2013/03/25
Altazimuth photoelectric theodolite level shaft U-type and T-type structure  but with the expanding field of applications of photoelectric theodolite  the horizontal shaft structure occur great changes. For example  in the marine environment  shipboard conditions  the instrument has a waterproof  corrosion-resistant  easy maintenance and other functions  while carrier-based optoelectronic devices from a single visible television configure the development of integrated infrared system and ranging system as one of the single-station measurement system  due to the spherical structure has sufficient internal space exactly adapted to this need. In this paper  the horizontal axis of a spherical four-way structure. From aspects of the spherical four-way split in the form and shafting design and finite element analysis of the detailed design. A spherical four-way horizontal axis system  diameter 550mm  weight 19kg sphere  in the 40kg load  the maximum deformation of 3.3m  fully meet the requirements. The shaft of the structure of the shaking is less than 2 arc seconds  the vibration test  the re-examination instrument accuracy change is less than 1 arc seconds. Verify that the structure is stable and reliable. 2012 IEEE.  
Space optical remote sensor of the CAE thermal control index calculation method (EI CONFERENCE) 会议论文  OAI收割
2011 International Conference on Advanced Design and Manufacturing Engineering, ADME 2011, September 16, 2011 - September 18, 2011, Guangzhou, China
作者:  Li L.
收藏  |  浏览/下载：33/0  |  提交时间：2013/03/25
The thermal control indicators CAE methods of Space optical remote sensor are analyzed in the presented work. We sat up a thermal optical analysis model for space optical remote sensor. By assuming fully covered by in-orbit temperature load  and using the finite element method for thermal deformation analysis  we obtained the optical remote sensor surface deformation and displacement under various thermal loading. Using ZERNIKE polynomial  wave was fitted to obtain ZERNIKE polynomial coefficients which were incorporated into the optical system design. Using CODE V optical calculation software  heat-ray machines under elastic deformation of the system point spread function  transfer function (MTF)  wave front differential (WFE) etc. were calculated. Image quality changes of remote sensors are discussed in variety assumed cases such as temperature loads of quality change. By repeated iteration  critical value of temperature fields meeting the design requirements are obtained for the optical system. Optical indicators were converged to the temperature field indicator  then reasonable indicators of thermal control for remote sensors were obtained. For the thermal control design  this method provided a reliable basis for design. (2011) 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.  
Evaluation of the operating range for ground-based infrared imaging tracking system (EI CONFERENCE) 会议论文  OAI收割
International Symposium on Photoelectronic Detection and Imaging 2011: Advances in Infrared Imaging and Applications, May 24, 2011 - May 24, 2011, Beijing, China
作者:  Zhang Z.-D.
收藏  |  浏览/下载：50/0  |  提交时间：2013/03/25
Ground-based infrared imaging tracking system (GIITS) is of great importance for aerial target warning and guard. The operating range is one of the key performance specifications  on the other  which should be calculated  calculate the radiation power received on the detector in order to analysis whether the output signal meets the detection requirements or not  analyzed and studied during the whole GIITS design process. The operating range is mostly influenced by a few factors  without considering the effect of the background radiation. By improving of the traditional method  including atmospheric attenuation  a new operating range calculation model of the GIITS was established based on two requirements. One is that the image size of observed target should meet the requirement of the processor signal extraction. The number of the pixel occupied by target image should be more than 9. The other is that the signal noise ratio (SNR) of the GIITS should not be less than 5 to meet the requirements of the target detection probability and spatial frequency. The SNR calculation equation in form of energy is deduced and the radiation characteristic of the observed target and background are analyzed. When evaluate the operating range of the GIITS using the new method  the performance of GIITS and feature of target and background. This paper firstly makes analysis and summarization on the definite localizations of the traditional operating range equation of the GIITS. The localizations are mainly in two aspects. On one hand  we should successively calculate two operating range values according to two requirements mentioned above and choose the minimum value as the analytic result. In the end  the dispersion of the image and the effect of image dispersion are not considered in the traditional method  an evaluation of operating range for fighter aircraft is accomplished as an example. The influence factors in every aspect on operating range were explored by the calculated result. The new operating range calculation model provides the theoretical basis for the design and applications as well as the comprehensive evaluation of a GIITS. 2011 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).