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Absolute Phase Retrieval Using One Coded Pattern and Geometric Constraints of Fringe Projection System 期刊论文
Applied Sciences (Switzerland), 2018, 卷号: 8, 期号: 12
作者:  Yang, Xu;  Zeng, Chunnian;  Luo, Jie;  Lei, Yu;  Tao, Bo
收藏  |  浏览/下载:6/0  |  提交时间:2019/12/04
Absolute phase retrieval via color phase-coding 期刊论文
OPTIK, 2017, 卷号: 140, 页码: 1056-1062
作者:  Cheng, Teng;  Du, Qingyu;  Jiang, Yaxi;  Zhu, Xingkui
收藏  |  浏览/下载:4/0  |  提交时间:2019/12/30
Improved method of target detection on optoelectronic hybrid joint transform correlator in cluttered scences (EI CONFERENCE) 会议论文
2011 3rd International Conference on Mechanical and Electronics Engineering, ICMEE 2011, September 23, 2011 - September 25, 2011, Hefei, China
Qian Y.; Yang L.; Cheng X.; Hong X.
收藏  |  浏览/下载:14/0  |  提交时间:2013/03/25
A classical joint transform correlator (JTC) usually yields large correlation sidelobes as well as a large correlation peak width  strong zero-order peak  and low diffraction efficiency  which make the detection ability of JTC lower. To overcome these difficulties  firstly  a joint power spectrum (JPS) subtraction technique in Fourier plane was proposed  where reference image power spectrum and object image power spectrum are subtracted from the JPS before inverse Fourier-transform operation  it is obvious that the modified JPS removes the zero-order term. Secondly  a fringe-adjusted filter (FAF) was presented to suppress sidelobes and noises. The modified JPS is multiplied by a FAF before the inverse Fourier-transform operation to obtain the cross-correlation peak. Computer simulations demonstrated the improved method can obviously remove zero-order diffraction and effectively suppress the sidelobes and noises compared with classic JTC  and then improve the detection ability for JTC. Experimental results presented the sharp correlation peak and also confirmed the method effectiveness. (2012) Trans Tech Publications  Switzerland.  
The design of computer-generated holograms for testing unsymmetrical optical surfaces (EI CONFERENCE) 会议论文
2012 International Symposium on Photonics and Optoelectronics, SOPO 2012, May 21, 2012 - May 23, 2012, Shanghai, China
Xu Y.; Lin H.; Zhu W.; Zhang Y.; Zhang X.
收藏  |  浏览/下载:18/0  |  提交时间:2013/03/25
Compensation of moire fringe sinusoidal deviation in photoelectrical encoder based on tunable filter (EI CONFERENCE) 会议论文
2011 Symposium on Photonics and Optoelectronics, SOPO 2011, May 16, 2011 - May 18, 2011, Wuhan, China
Wang Y.; Liu Y.; Yan X.; Chen X.; Lv H.
收藏  |  浏览/下载:21/0  |  提交时间:2013/03/25
In order to improve the precision of the absolute photoelectrical encoder  a compensating method is put forward  which restrains the harmonics in moire fringe signal. After analyzing the relationship between the subdividing error and the sinusoidal index  a low-pass digital filter which can make the moire signal satisfy the need of 1024 subdivision is designed. Considering with the fundamental frequency varies with the rotating speed of encoder  the tunable filter is adopted  whose cutoff frequency is calculated according to the coarse information of the encoder. The simulating results show that the proposed method can improve the sinusoidal index  especially at high rotating speed. At last  the compensating algorithm is implemented in the terminal of satellite optical communication  which needs high resolution. The experimental results show indicate that the developed method is feasible. 2011 IEEE.  
The Research of real time auto-recognition of the moire fringe (EI CONFERENCE) 会议论文
International Symposium on Photoelectronic Detection and Imaging 2011: Advances in Imaging Detectors and Applications, May 24, 2011 - May 26, 2011, Beijing, China
Wang M.-J.; Wu Z.-G.
收藏  |  浏览/下载:16/0  |  提交时间:2013/03/25
Measuring the movement of raster by the method of moire fringe has the advantage of high sensitivity  high resolution and non-contacted measurement. The characteristic of moire fringe is that the image is white alternate with black  the angle of the stripes is uniform  the width of the stripes is uniform  the terminators of the stripes aren't clear. A fast method that can figure out the width and angle of the moire fringe precisely is put forward in this paper. It calculates the angle the stripes firstly. According to the principle of the minimum mean squared error (MMSE)  the closer a series of data is  the smaller the value of the MMSE will be. The method is described as follows: It takes the image's center as the origin  180 beelines pass through the origin with the same angle interval. it calculates the value of the minimum mean squared error of the 180 beelines and find out the least one among those  then the angle of the moire fringe comes out primarily. In order to improving the calculating precision of moire fringe  60 equal angles are divided in the neighborhood of the angle  then a precise angle of moire fringe is calculated according to the principle of the MMSE. After getting out the angle of the moire fringe  we begin to calculate the width of moire fringe. A line vertical with the moire fringe is drawn  and we can get the width of the moire fringe by the vertical line. In order to get over the influence of the noise  an effective area with the shape of diamond is selected in the image. The data of area is accumulated and projected according to the direction of moire fringe  and a sine curve come out. The width of moire fringe can be obtained by getting the position of the first wave crest  the position of the last wave crest and the number of wave crest. Experiments prove that the precision of the method put forward in this paper is enhanced in comparison with the traditional frequency method  the precision of width calculation achieves to 99.6% according to the evaluation indicators of width detection error. The computing speed is boosted largely compared with traditional method  and it can achieve with 15 ms  that satisfying the demand of real time. 2011 SPIE.  
A study on the multiplication technique of nano-moire Fringe 期刊论文
2010, 2010
Liu Zhanwei; Xie Huimin; Fang Daining; Dai Fulong; Wang Weining; Fang Yan
收藏  |  浏览/下载:4/0
Improvement of measurement error for modified coherent gradient sensing 期刊论文
2010, 2010
Yao, XF; Xu, W; Yeh, HY
收藏  |  浏览/下载:4/0
Graph fitting test method for the interpolation error of Moire fringe (EI CONFERENCE) 会议论文
9th International Conference on Electronic Measurement and Instruments, ICEMI 2009, August 16, 2009 - August 19, 2009, Beijing, China
Wan Q.; Sun Y.; She R.; Liang L.; Lu X.; Du Y.
收藏  |  浏览/下载:23/0  |  提交时间:2013/03/25
In order to realize the fast test for the interpolation error  the graph fitting test method for the interpolation error of Moire fringe is put forward in this paper. Firstly  the triangular wave Moire fringe photoelectric signal of the encoder whose phase difference is 90 are sampled to get the Lissajous graph of the two signals. Secondly  the single wave represented by the founded subsection function is used to fit the practical Moire fringe Lissajous graph. Then  the fitting result is tested to verify whether it satisfies the accuracy requirement. Lastly  the founded subsection function instead of the practical wave function is used to calculate the interpolation error. Using the graph fitting method to sample the Moire fringe single of 15-bits photoelectric encoder to get the interpolation error curve  the tested maximum interpolation error is 70" and the minimum error is - 69". Comparing with the interpolation error which is received from traditional test method  the change trend of the interpolation error curve is similar  and peak-peak value is almost equality. The results of experiment indicate that: the equipment is convenient and the examination method is efficient and feasible. The measure speed is fast and the manifestation result is intuitionistic. The system can be used in the working field. The method can avoid the speed influence and realize the dynamic interpolation error measure  which is significant for the research of encoder's dynamic accuracy characteristics. 2009 IEEE.  
Fine interference fringes formed in high-order harmonic spectra generated by infrared driving laser pulses 期刊论文
phys. rev. a, 2008, 卷号: 78, 期号: 3, 页码: 33841
Xu Han; Xiong Hui; 曾志男; Fu Yuxi; Yao Jinping; 李儒新; 程亚; 徐至展
收藏  |  浏览/下载:1234/223  |  提交时间:2009/09/18


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