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A signal process system for photoelectric encoder based on C8051F021 MCU (EI CONFERENCE) 会议论文  OAI收割
2nd World Congress on Computer Science and Information Engineering, CSIE 2011, June 17, 2011 - June 19, 2011, Changchun, China
作者:  
Gao X.
收藏  |  浏览/下载:27/0  |  提交时间:2013/03/25
Design of a miniature axial flux flywheel motor with PCB winding for nanosatellites (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
Wu J.
收藏  |  浏览/下载:43/0  |  提交时间:2013/03/25
This paper presents the design and analysis of an axial flux permanent-magnet (AFPM) machine for nanosatellites application. It is a miniature axial flux surface mounted permanent magnet flywheel motor  using a printed circuit board (PCB) stator winding. The PCB stator has simplified the design and construction and avoids unnecessary space  since size reduction has become one of the most important aspects of flywheel motor design for nanosatellites. The performances of the machine are estimated by combination method of three-dimensional (3D) electromagnetic finite element analysis (FEA) and approximate theoretical analysis. The back EMF and electromagnetic torque are derived. A comparison between the analysis and experimental measurement results of the prototype machine is also presented. Both simulated and experimental results show that the proposed motor would be an acceptable solution for the nanosatellite applications with advantages such as simple structure and low-cost  as multi-layer circuit board production techniques have made the production of printed circuit coils cheaper and easier. 2012 IEEE.  
Study on spectrograph for ionosphere: A broadband imaging instrument prototype for far-ultraviolet (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
作者:  
Wang S.-R.;  Lin G.-Y.;  Yu L.
收藏  |  浏览/下载:39/0  |  提交时间:2013/03/25
Current research on space-based exploration for the ionosphere needs more advanced technologies. Because the spectral signals in the ionosphere distributing basically in the far-ultraviolet waveband are very weak. Usual spectrometer structures and detectors such as CCD can't receive enough information. Based on this principle of atmospheric sounding  the imaging spectrometer prototype for ionosphere detection application was designed to solve the problem. This prototype consists of the telescope and the imaging spectrometer. The simple structure and small number of mirrors can help higher transmission efficiency be achieved and weak signals detection be implemented. The telescope is an off-axis parabolic mirror and the spectrometer is a modified Czerny-Turner spectral imaging system. Modified Czerny-Turner spectrometer contains a spherical mirror  a fixed plane grating and a toroidal mirror. By adjusting the incident angle to the collimating mirror and using toroidal mirror  coma and astigmatism were corrected well. We also optimize distances between the grating to the focusing mirror and the focusing mirror to the image plane to improve disadvantages of traditional Czerny-Turner structure. Designed results demonstrate that aberrations are substantially corrected  and high image quality can be obtained in broad waveband. The photon counting Wedge-Strip-Anode detector with micro-channel planes as the receiving plane is accepted for the instrument prototype. The other photon counting 2-D detector responding well for weak light such as Cross-Delay line detector and MAMA detector can also be used for detection. The calibration and performances testing system is made of a vacuum system  a deuterium lamp  a monochrometer and the instrument prototype. Results obtained from the experiment show that the spectral resolution is 2.4 nm and the spatial resolution is 80 m. The other calibration experiments are running. The technology of the spectrometer prototype is important for the research and applications of ionosphere remote sensing. 2011 SPIE.  
Precision detection of CCD splicing based on template matching algorithm (EI CONFERENCE) 会议论文  OAI收割
IEEE 2nd International Conference on Computing, Control and Industrial Engineering, CCIE 2011, August 20, 2011 - August 21, 2011, Wuhan, China
作者:  
Zhang X.;  Zhang X.;  Yang L.;  Zhang X.;  Yang L.
收藏  |  浏览/下载:33/0  |  提交时间:2013/03/25
The remote sensing camera in large field and wide cover needs CCD with enough pixels. But the existing CCD cannot satisfy the practical needs. Therefore several pieces of CCD which has insufficient pixels are spliced to get a long CCD array with plenty of pixels. The precision requirements of CCD splicing are very strict  so that the same high accuracies are required in the precision detection of CCD splicing. When detecting precision of CCD splicing  the graphical markers with simple geometric structure in the CCD package are selected as templates. The position precision data of the graphical markers in each CCD are obtained using the template matching algorithm. Using the unified objective templates  the focal plane which has multi-chip of CCD is detected by template matching algorithm. Experiment results show that the template matching algorithm can enhance the located precision of each CCD to 0.347m. The splicing precision detection with template matching algorithm can avoid the subjective error caused by the conventional detection method. And its results are more accurate. In addition  without manual intervention in the process of precision detection  the efficiency of precision detection is improved. 2011 IEEE.  
Autocollimation form dual-frequency laser diffraction grating interferometer design and analysis (EI CONFERENCE) 会议论文  OAI收割
2010 International Conference on Computer, Mechatronics, Control and Electronic Engineering, CMCE 2010, August 24, 2010 - August 26, 2010, Changchun, China
Wang C.-G.
收藏  |  浏览/下载:42/0  |  提交时间:2013/03/25
Propose a new measurement system of autocollimation form laser grating heterodyne interferometer. Take grating diffraction and polarization optics as theoretical foundation  second  furthermore  combined with electronics knowledge to analyze the system. First  make use of autocollimation diffraction of grating  measurement information obtained by dual-frequency laser belongs to ac signal  the interferometer measurement system take grating pitch as measuring datum  the structure is simple  possess great gain and high signal-noise ratio  therefore  stable  completely overcome the disadvantages of DC level drift caused by light intensity variation of single-frequency laser  system can achieve nanometer resolution. 2010 IEEE.  reduce the impact of environmental factors  easy to install and debug  measurement error is small  
A digital image processing system based on DSP (EI CONFERENCE) 会议论文  OAI收割
2nd International Conference on Information Engineering and Computer Science, ICIECS 2010, December 25, 2010 - December 26, 2010, Wuhan, China
作者:  
Liu Y.;  He X.;  Liu Y.;  Liu Y.
收藏  |  浏览/下载:12/0  |  提交时间:2013/03/25
Target characteristic extraction algorithm based on block structure variables (EI CONFERENCE) 会议论文  OAI收割
2010 3rd International Conference on Advanced Computer Theory and Engineering, ICACTE 2010, August 20, 2010 - August 22, 2010, Chengdu, China
作者:  
Zhou Y.;  Yang H.;  Yan F.;  Yan F.
收藏  |  浏览/下载:29/0  |  提交时间:2013/03/25
Transmission properties of multiband fss based on fractal elements (EI CONFERENCE) 会议论文  OAI收割
2010 9th International Symposium on Antennas Propagation and EM Theory, ISAPE 2010, November 29, 2010 - December 2, 2010, Guangzhou, China
作者:  
Gao J.
收藏  |  浏览/下载:27/0  |  提交时间:2013/03/25
Optical system of large relative aperture and wide field using aspheric corrector for detecting (EI CONFERENCE) 会议论文  OAI收割
4th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Advanced Optical Manufacturing Technologies, November 19, 2008 - November 21, 2008, Chengdu, China
作者:  
Zhang J.;  Zhang J.;  Zhang J.;  Wang J.
收藏  |  浏览/下载:25/0  |  提交时间:2013/03/25
The magnitude requirement of space target detecting determines that the image of detecting telescope should have several performances: small spots  the wider field of view  small 80% encircled energy diameter and good MTF(Modulation transfer function). So the aperture and field of view of optical system have some demands accordingly. The larger aperture  the more extensive range which the telescope searches. Now most of ground telescopes whose apertures are from 500mm to 1000mm is on-axis optical system  the more energy that telescope collects and higher magnitude the telescope detects  so wide field of view becomes the most importance problem. To obtain large relative aperture and wide field of view  the paper introduces a catadioptric telescope with small aperture aspheric refractive corrector  whose conic surface will be used to remove the aberrations due to large relative aperture and wide field of view. As to the optical system  there is only one aspheric refractive corrector  and it is relatively easy for manufacturing because of its concave figure and normal material. The paper gives the example  and optimizes this optical system with ZEMAX program. And then the paper provides a specific analysis program for testing the aspheric refractive corrector. The aperture of this optical system is 750mm  and its relative aperture is 0.82  and the field of view is 3.6 diameter(diagonal). Its structure is simple and the image quality is also very good. 2009 SPIE.  
Design of dual-FOV refractive/diffractive LWIR optical system (EI CONFERENCE) 会议论文  OAI收割
3rd International Symposium on Advanced Optical Manufacturing and Testing Technologies, AOMATT 2007: Advanced Optical Manufacturing Technologies, July 8, 2007 - July 12, 2007, Chengdu, China
作者:  
Wang L.-J.;  Zhang J.-P.;  Wang L.-J.;  Zhang X.;  Zhang X.
收藏  |  浏览/下载:43/0  |  提交时间:2013/03/25
An infrared-optical zoom system using binary element is proposed in this paper. The two main advantages of the zoom system introducing here are: bigger F-number and lower cost. The primary optical properties are: F/#=1  Second  Others  zoom ratio =1:4  binary element is used to correct the chromatical aberration by taking the advantage of negative dispersion characteristics and the cost of the system is lower than that of conventional ones with Zinc Selenide (Znse) material at the same level. In the binary element is rotational symmetric with one step which is easy to fabricate  in order to balance 5th spherical aberration  and dual field are 26.6 and 5.6respectively. Wider field of view is used for search and the smaller one is used for imaging details. This system uses un-cooled infrared detector with 320240 pixels and 45m pixel size. The F-number matches the sensitivity range of the detector array. Three aspects are considered during design process to make the system more satisfactory and more achievable. First  5th coma aberration and 5th astigmatic aberration  the manner of zoom is accomplished by exchanging tow lenses into the smaller field of view system layout. The lens exchange manner faces the requirement of simple system structure and good image quality in both focal points. It can also make the system more feasible in the alignment process than mechanical-zooming manner and optical-zooming manner  high-order asphere surfaces with 2th order to 10 th order are also hired in the system. Asphere surface is useful in compressing the system and improving optical system transmittance. This kind asphere surface is on industrial level featuring low cost and easy to fabricate. It is shown that good image quality can achieved by implementing five Germanium lenses and the transmittance of system is 72%. All aberrations are diffraction-limited  both spherical aberration and astigmatic aberration are corrected. When the field of view(FOV) is 26.6 and the focal length is 152mm  MTF at Nyquist frequency(11lp/mm) is great than 0.7. The spherical aberration is -0.0073. The coma aberration is 0.0978 and the astigmatic aberration is -0.013. When the field of view(FOV) is 5.6 and the focal length is 38mm  MTF at Nyquist frequency is great than 0.8 with spherical aberration -0.0046  the coma aberration 0.055 and astigmatic aberration 0.034.