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Structural design and simulation analysis of ejector used in automotive power steering oil discharge equipment (EI CONFERENCE) 会议论文  OAI收割
2012 International Conference on Mechanical Engineering, Materials Science and Civil Engineering, ICMEMSCE 2012, August 18, 2012 - August 20, 2012, Harbin, China
Cheng K.; Zou H.; Kong X.; Tang J.
收藏  |  浏览/下载:28/0  |  提交时间:2013/03/25
Comparison and simulation of subpixel imaging modes for linear CCD (EI CONFERENCE) 会议论文  OAI收割
2012 3rd International Conference on Information Technology for Manufacturing Systems, ITMS 2012, September 8, 2012 - September 9, 2012, Qingdao, China
作者:  
Li Y.;  He B.;  Li Y.;  Li Y.;  Li Y.
收藏  |  浏览/下载:40/0  |  提交时间:2013/03/25
Subpixel technique of linear CCD is effective to enhance the spatial resolution without increasing the focal length of optics and reducing the pixel size. To compare image quality of two main subpixel imaging modes  quincunx sampling and four-point sampling  a method to quantitatively evaluate image quality of subpixel based on MTF was proposed. The MTF of quincunx and four-point sampling modes were derived. Analytical results shows that theoretical limiting resolution of quincunx sampling and four-point sampling is improved to 1.4 and 1.86 times respectively  and MTF values at Nyquist frequency of two modes are increased by 0.1106 and 0.1679  respectively. MTFA in (0  0.5) of two subpixel imaging modes were calculated and results illustrates that four-point sampling offers much more improvement with image quality than quincunx sampling  at the cost of double amount of data. A model for simulating subpixel imaging using Matlab was established  and simulation results of spoke target verify the theoretical analysis. (2012) Trans Tech Publications  Switzerland.  
The effect of backlash nonlinear on resonance frequency of electric actuator transmission system (EI CONFERENCE) 会议论文  OAI收割
3rd IEEE International Conference on Advanced Computer Control, ICACC 2011, January 18, 2011 - January 20, 2011, Harbin, China
Han X.; Ge M.; Bai Y.; Jia H.; Ge W.
收藏  |  浏览/下载:26/0  |  提交时间:2013/03/25
In order to study the effect of backlash nonlinear on resonance frequency of electric actuator transmission system  then  Finally  in the premise of meeting the stability  the dynamic equilibrium equation of transmission system with backlash is established  it makes dynamic simulation analysis for the transmission system based on virtual prototype technology  it establishes balanced equation of dynamics system with backlash  the effect of backlash on system natural frequency and resonance frequency  and the theoretical values and simulation values are compared. Theoretical analysis and simulation results show that the theoretical analysis is basically consistent with simulation results when it is zero backlash  and does some theory research and dynamic analysis of backlash nonlinearity and system natural frequency and resonance frequency. First  and the error of theoretical analysis and simulation results is within 10%. Therefore  according to describing function to theoretically model the backlash nonlinear  it can be concluded that considering the transmission system theoretical analysis of backlash nonlinearity is feasible  the relation between describing function and the amount of backlash and input amplitude is analyzed  and it is much closer to the actual system with instructive significance. 2011 IEEE.  
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).  
Rearrangeable nonblocking 88 matrix optical switches based on extended banyan network (EI CONFERENCE) 会议论文  OAI收割
作者:  
Zhang Y.
收藏  |  浏览/下载:29/0  |  提交时间:2013/03/25
Based on the CROSSBAR network (CN) and the BANYAN network (BN)  8 matrix optical switch  two new rearrangeable nonblocking constructions of extended BANYAN network (EBN) are proposed for implementing 88 optical matrix switch. The interconnection characteristics of these two types of rearrangeable nonblocking EBN were studied  optical insertion loss of 4.6 dB  and the logic program for driving switching units was provided. The calculated insertion loss was 3.3 dB for 88 optical matrix switch. Silica waveguide 88 matrix optical switch was designed and fabricated according to the calculated results. The silica waveguide propagation loss of 0.1 dB/cm and waveguide-fiber coupling loss of 0.5dB/point were measured. With the fabricated 87times  cross-talk of -38 dB  polarization dependent loss of 0.4 dB  averaged switching power of 1.6 W  and switching time of 1 ms were achieved. A basic agreement between experimental results and theoretical calculated values was achieved.  
Three-port beam splitter of a binary fused-silica grating 期刊论文  OAI收割
appl. optics, 2008, 卷号: 47, 期号: 35, 页码: 6638, 6643
Feng Jijun; 周常河; Wang Bo; 郑将军; Jia Wei; Cao Hongchao; Lv Peng
收藏  |  浏览/下载:1497/363  |  提交时间:2009/09/18
Rearrangeable nonblocking 88 matrix optical switch based on silica waveguides and extended banyan network (EI CONFERENCE) 会议论文  OAI收割
Science and Technology of Dielectrics for Active and Passive Photonic Devices - 210th Electrochemical Society Meeting, October 29, 2006 - November 3, 2006, Cancun, Mexico
作者:  
Zhang Y.
收藏  |  浏览/下载:30/0  |  提交时间:2013/03/25
Based on the CROSSBAR network (CN) and the BANYAN network (BN)  two new rearrangeable nonblocking constructions of extended BANYAN network (EBN) were proposed for implementing 88 optical matrix switch. The interconnection characteristics of these two types of rearrangeable nonblocking EBN were studied  and the driver logic program of switching units was provided. The calculated insertion loss is 3.3 dB for 88 optical matrix switch. Silica waveguide 88 matrix optical switch was designed and fabricated according to the calculated results. The silica waveguide propagation loss of 0.1 dB/cm and waveguide-fiber coupling loss of 0.5dB/point were measured out. With the fabricated 88 matrix optical switch  optical insertion loss of 4.6 dB  cross-talk of -38 dB  polarization dependent loss of 0.4 dB  averaged switching power of 1.6 W  and switching time of 1 ms were achieved. A basic agreement between experimental results and theoretical calculated values was achieved. copyright The Electrochemical Society.  
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