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Study on the sensitivity of temperature gradient for large aperture SiC lightweight mirror based on active optics 会议论文
7th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Large Mirrors and Telescopes, AOMATT 2014, April 26, 2014 - April 29, 2014, Harbin, China
Liu X.; Zhang J.; Wu X.; Li J.; Guo P.; An Q.
收藏  |  浏览/下载：16/0  |  提交时间：2015/04/27
Realization of the FPGA based TDI Algorithm in Digital Domain for CMOS Cameras 会议论文
2012
Tao S. P.; Jin G.; Zhang X. Y.; Qu H. S.
收藏  |  浏览/下载：10/0  |  提交时间：2013/03/28
Design of astromesh deployable concentrator used in space concentrating photovoltaic system 会议论文
2012
Ma H. C.; Jin G.; Zhong X.; Zhang Y.; Zhang P.
收藏  |  浏览/下载：8/0  |  提交时间：2013/03/28
Study on ultra-light secondary baffle for coaxial two-mirror telescope (EI CONFERENCE) 会议论文
2012 9th IEEE International Conference on Mechatronics and Automation, ICMA 2012, August 5, 2012 - August 8, 2012, Chengdu, China
Zhang L.; Jia X.; Xie P.; Xing L.
收藏  |  浏览/下载：44/0  |  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.  
Wavefront Error Sensing based on Phase Diversity Technology and Image Restoration 会议论文
2012
Cheng Q.; Li F. Z.; Tao X. P.; Yan F.; Zhang X. J.
收藏  |  浏览/下载：7/0  |  提交时间：2013/03/28
Surface shape optimization for the space membrane reflector (EI CONFERENCE) 会议论文
2011 International Conference on Electronic and Mechanical Engineering and Information Technology, EMEIT 2011, August 12, 2011 - August 14, 2011, Harbin, China
Zhang P.; Jin G.; Zhong X.; Zhang Y.; Qi Y.-C.; Jie P.
收藏  |  浏览/下载：16/0  |  提交时间：2013/03/25
Space membrane reflector is very promised for optical quality application with the merits of ultra-lightweight and flexible. In order to improve the surface precision of membrane reflectors  the formation and surface shape error of a membrane at uniform load are studied based on the henky-cambell equations of circular membrane. The ANSYS software is used to build an optimization model of membrane reflector surface shape  in which the yield strength is the state variable  the surface load on ten concentric annular regions of the mirror is the design variable  and the minimum RMS between ideal surface and mirror surface is the target function. and the theoretical and experimental result show that RMS and PV of the optimized surfaces are reduced respectively than those before optimization. In a word  this paper offers the theoretical and experimental basis of the polyimide membrane reflector. 2011 IEEE.  
Research of VGA Display for 2048 Resolution Power Linear CCD Based on SOPC 会议论文
2011
Zhang Y. X.; Ge W. Q.; Xu Z. P.; Li D. N.; Liu Y.; Leng X.; Chen X. H.
收藏  |  浏览/下载：28/0  |  提交时间：2013/03/28
Approach for detecting crowd panic behavior based on fluid kinematic features and entropy (EI CONFERENCE) 会议论文
International Workshop on Advanced Computational Intelligence and Intelligent Informatics, IWACIII 2011, November 19, 2011 - November 23, 2011, Suzhou, China
Cao S.; Zhang X.; Cao W.; Liu C.; Li Y.; Li P. C.
收藏  |  浏览/下载：21/0  |  提交时间：2013/03/25
The design of high speed image acquisition system over Gigabit Ethernet (EI CONFERENCE) 会议论文
2010 IEEE International Conference on Wireless Communications, Networking and Information Security, WCNIS 2010, June 25, 2010 - June 27, 2010, Beijing, China
Zhang W.; Wei Z.; He X.; Qiao P.; Liang G.
收藏  |  浏览/下载：23/0  |  提交时间：2013/03/25
The applications based on traditional digital cameras have been limited by distance  cost and networking. Gigabit Ethernet is a data transmission standard based on the IEEE 802.3 protocol  brings several benefits to image transmission. In this paper  we compare the main features of Gigabit Ethernet and traditional digital camera interfaces. And  we design a high speed image acquisition system which overcomes these application limitations by allowing cameras to send imaging data over Gigabit Ethernet. In this system  we design a highly efficient  bidirectional conversion device based on FPGA  converts imaging data from a camera to IP packets based on UDP protocol  and sends it to PCs over inexpensive Cat-5 copper LAN cable. At the PC  the Cat-5 cable plugs into a standard Gigabit Ethernet NIC(network interface card)  eliminating the need for a frame grabber. An communications application software is used to acquire the network data  construct and display the image. A simple and efficient acknowledge and resend mechanism was used to guarantee packet delivery. The system architecture and the communication protocol are discussed in details  the experiment and results are presented in this paper. 2010 IEEE.  
Research on automatic Hartmann test of membrane mirror (EI CONFERENCE) 会议论文
5th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Optical Test and Measurement Technology and Equipment, April 26, 2010 - April 29, 2010, Dalian, China
Zhong X.; Jin G.; Liu C.; Zhang P.
收藏  |  浏览/下载：20/0  |  提交时间：2013/03/25
Electrostatic membrane mirror is ultra-lightweight and easy to acquire a large diameter comparing with traditional optical elements  so its development and usage is the trend of future large mirrors. In order to research the control method of the static stretching membrane mirror  the surface configuration must be tested. However  membrane mirror's shape is always changed by variable voltages on the electrodes  and the optical properties of membrane materials using in our experiment are poor  so it is difficult to test membrane mirror by interferometer and null compensator method. To solve this problem  an automatic optical test procedure for membrane mirror is designed based on Hartmann screen method. The optical path includes point light source  CCD camera  splitter and diffuse transmittance screen. The spots' positions on the diffuse transmittance screen are pictured by CCD camera connected with computer  and image segmentation and centroid solving is auto processed. The CCD camera's lens distortion is measured  and fixing coefficients are given to eliminate the spots' positions recording error caused by lens distortion. To process the low sampling Hartmann test results  Zernike polynomial fitting method is applied to smooth the wave front. So low frequency error of the membrane mirror can be measured then. Errors affecting the test accuracy are also analyzed in this paper. The method proposed in this paper provides a reference for surface shape detection in membrane mirror research. 2010 Copyright SPIE - The International Society for Optical Engineering.  

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