Journals >Opto-Electronic Engineering
Contents
2009
Volume: 36 Issue 6
29 Article(s)
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Research Article
Optical Compensated Step Zoom Lens
SHI Guang-hui
According to the theory of optical compensated zoom, author designed optical compensated step zoom lenses. Compared with traditional step zoom which makes use of extender to change focal length, this kind of step zoom lens has two advantages. Firstly, the zoom ratio may be enlarged. Secondly, the image point movement mAccording to the theory of optical compensated zoom, author designed optical compensated step zoom lenses. Compared with traditional step zoom which makes use of extender to change focal length, this kind of step zoom lens has two advantages. Firstly, the zoom ratio may be enlarged. Secondly, the image point movement may be easily eliminated. The principle of optical compensated step zoom lens is explained. Three examples, one step zoom with zoom ratio 2.5×, two steps zoom with 16× and three steps zoom with 8× are given in this paper..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 36, Issue 6, 1 (2009)
Design of the Digital Control System for Seeker Based on Dual DSP
ZHU Hua-zheng, FAN Da-peng, MA Dong-xi, and ZHANG Wen-bo
The structure of seeker servo system and the function of its servo loop including locking, stabilization, searching and tracking were analyzed. Based on the structure of dual DSP, a controller for seeker control system was designed in order to realize the function of communication, disturbance isolation and target tracThe structure of seeker servo system and the function of its servo loop including locking, stabilization, searching and tracking were analyzed. Based on the structure of dual DSP, a controller for seeker control system was designed in order to realize the function of communication, disturbance isolation and target tracking. And the hardware configuration and software structure were introduced. The theory of disturbance isolation and target tracking of seeker servo system was analyzed. A method for designing a digital controller based on dSPACE hardware-in-the-loop simulation system was proposed by designing a controller for yawing stabilization loop. Experimental results of disturbance isolation and target tracking show that the digital control system for seeker designed in this paper has good performance, and can satisfy the requirements of disturbance isolation and target tracking function of seeker..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 36, Issue 6, 4 (2009)
Fusion Tracking of Radar/IR Dual-mode Seeker with Radar under Intermittent-working State
ZENG Xian-wei, FANG Yang-wang, WANG Feng, SUN Liang1, and LU Hu
Aiming at the homing problem of the missile under strong counterwork during the terminal guidance, a new fusion tracking algorithm for the radar of the Radar/IR dual-mode missile under intermittent-working state was presented. This algorithm decreased the warning probability of the enemy fighter, the intercepting probaAiming at the homing problem of the missile under strong counterwork during the terminal guidance, a new fusion tracking algorithm for the radar of the Radar/IR dual-mode missile under intermittent-working state was presented. This algorithm decreased the warning probability of the enemy fighter, the intercepting probability of the enemy missile and the probability of radar being locked–on by Electronic Support Measure (ESM) by decreasing the working time of the radar. To improve tracking precision, the IMM algorithm and UKF algorithm were combined and then applied to the fusion tracking of the radar and the infrared. Simulation results show that, compared with the single infrared tracking, the algorithm improves the tracking precision, decreases the working time of the radar and increases the probability of the hit..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 36, Issue 6, 10 (2009)
Precisely Tracking Trajectory of Ping-pong Robot Based on Air Drag Factor Estimation
ZHANG Yuan-hui, WEI Wei, and YU Dan
To solve the tracking error caused by camera image distortion, motion blurring, air drag and other uncertain factors, a tracking algorithm based on air “drag factor” estimation was presented in this paper. This algorithm incorporated the tracking advantage of Kalman filter, added a “drag factor” term which was deduced To solve the tracking error caused by camera image distortion, motion blurring, air drag and other uncertain factors, a tracking algorithm based on air “drag factor” estimation was presented in this paper. This algorithm incorporated the tracking advantage of Kalman filter, added a “drag factor” term which was deduced from aerodynamics theory to state vector, and re-modeled the augmented non-linear state equations. Finally, a non-linear extend Kalman filter was applied to estimate the model’s states. The experimental results indicate that the improved method has more precise output than traditional tracking algorithm (velocity noise reduced from 0.5 m/s to 0.2 m/s). Its efficiency and low calculation load in computation was also proved..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 36, Issue 6, 15 (2009)
Edge Detection Algorithm Based on Fractal Features
DONG Wen-ming, WU Le-hua, and JIANG De-lei
The edge extraction from images plays a key role in the elementary processing of computer vision system, but it’s still a bottleneck problem. This thesis mainly paid attention to the issues related to the detection of the edges from the complicated nature background, and an improved method for edge detecting was presenThe edge extraction from images plays a key role in the elementary processing of computer vision system, but it’s still a bottleneck problem. This thesis mainly paid attention to the issues related to the detection of the edges from the complicated nature background, and an improved method for edge detecting was presented based on the fractal features. Furthermore, a new method about how to calculate the fractal dimension and the intercept feature was proposed by applying the property of fractional Brownian motion to the algorithm proposed. Then, based on the fractal dimension and intercept features, a measure method for discriminating edges of man-made object from natural scenes was provided. Experiments show that the proposed algorithm can detect the edges effectively, at the same time the runtime is reduced greatly..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 36, Issue 6, 21 (2009)
Detection of Rust in Citrus with Hyperspectral Imaging Technology
CAI Jian-rong, WANG Jian-hei, HUANG Xing-yi, and CHEN Quan-sheng
Hyperspectral imaging technology, a new Non-destructive Testing (NDT) technology of agricultural products, was attempted to detect external quality of citrus. Detection of rust in citrus was studied in this work. Firstly, Principal Component Analysis (PCA) was performed on hyperspectral imaging data after preprocessingHyperspectral imaging technology, a new Non-destructive Testing (NDT) technology of agricultural products, was attempted to detect external quality of citrus. Detection of rust in citrus was studied in this work. Firstly, Principal Component Analysis (PCA) was performed on hyperspectral imaging data after preprocessing to determine three dominant wavelengths (i.e. 571, 652, 741 nm). Secondly, the datacube composed of three dominant wavelength images was analyzed based on PCA again, and the third Principal Component (PC3) image was found to be most suitable for identifying the presence of rust. Finally, rust features on citrus’s surface were segmented by median filtering, square root transformation, determination of optimal threshold and morphological imaging processing. Experimental results show that the rust in citrus can be detected with an accuracy of 90%. This work demonstrates that it is feasible to detect rust in citrus by using the hyperspectral imaging technology and twice steps PCA..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 36, Issue 6, 26 (2009)
Hyperspectral Image Compression Method Based on Non-uniform Wavelet Transform
CHEN Lei, ZHANG Xiao-lin, YANG Wei-song, and HAN Song
A new hyperspectral image compression method is proposed by use of the separable non-uniform decoupled 3-D wavelet transform. The method is designed according to the fact that the properties of the different dimensions are distinctly unlike in the hyperspectral images. Traditional 3-D wavelet transform uses same waveleA new hyperspectral image compression method is proposed by use of the separable non-uniform decoupled 3-D wavelet transform. The method is designed according to the fact that the properties of the different dimensions are distinctly unlike in the hyperspectral images. Traditional 3-D wavelet transform uses same wavelet base for the different dimensions and the frequency spectrum of 3D filters is identical. So we apply different wavelet bases to different dimensions, and design the method with the decoupled wavelet structure. In order to obtain the optimal combination of the wavelet bases, four evaluation items are used. Result shows that the new 3-D hyperspectral image compression method can significantly improve the compression ratio without sacrificing other features such as scalability and computational efficiency..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 36, Issue 6, 31 (2009)
A Binocular Vision Simplified System for the Surgical Navigation
ZHANG Peng-wei, ZHANG Zhi-quan, HU Lei, and LUAN Sheng
In view of the complexity in the calibration process and the discrepancy in point matching, a simplified binocular vision positioning system for surgical navigation was developed. The system could calculate the 24 parameters once and for all with the coordinate transformation method. In addition, the gridiron pattern mIn view of the complexity in the calibration process and the discrepancy in point matching, a simplified binocular vision positioning system for surgical navigation was developed. The system could calculate the 24 parameters once and for all with the coordinate transformation method. In addition, the gridiron pattern marker and the principle of similarity measure were adopted to simplify the stereo matching process and to improve the stereo matching accuracy. Then, the calibrated system detected the distance between the pairs of markers which were within 1.5 m distance from the binocular vision sensing units, and the error was less than 1 mm. The new system was tested in the anterior cruciate ligament reconstruction surgery. It is proved that the system is stable, reliable, easy to be calibrated with sufficient accuracy and high positioning precision, and can meet the requirements of surgical navigation..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 36, Issue 6, 37 (2009)
Influence of Atmospheric Turbulence on the Axial Intensity of Bessel-Gauss Beams
MA Xiu-bo, and LI En-bang
Light intensity fluctuation is caused by atmospheric turbulence while laser beam travels in atmosphere. In order to find an approach to weaken or remove the effect of turbulence, the influence of atmospheric turbulence on the axial intensity of Bessel-Gauss Beams of zero-order was investigated by means of numerical simLight intensity fluctuation is caused by atmospheric turbulence while laser beam travels in atmosphere. In order to find an approach to weaken or remove the effect of turbulence, the influence of atmospheric turbulence on the axial intensity of Bessel-Gauss Beams of zero-order was investigated by means of numerical simulation. The results show that the axial intensity of Bessel-Gauss beams decreases with the increase of propagation distance, and the stronger the atmospheric turbulence is, the faster the axial intensity decreases. The smaller the radial wave vectors of the Bessel-Gauss beams of zero-order, the better the stability of their axial intensity. The stability of axial intensity of Bessel-Gauss beams gets worse with the increase of propagation distance. Compared with Gaussian beams with the same beam width, the axial intensity of Bessel-Gauss beams is more affected by atmospheric turbulence..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 36, Issue 6, 42 (2009)
Signal-to-noise Ratio and Doppler Current of Laser Doppler Velocimeter
ZHOU Jian, FENG Qing-qi, LONG Xing-wu, WEI Guo, and SONG Rui
The formula for calculating the signal-to-noise ratio is researched and showed in reference beam Laser Doppler Velocimeter. The effect of light spot size and size of light sensing surface on signal-to-noise ratio is analyzed from numerical simulation. Moreover, the formula of the Doppler current is given while the effeThe formula for calculating the signal-to-noise ratio is researched and showed in reference beam Laser Doppler Velocimeter. The effect of light spot size and size of light sensing surface on signal-to-noise ratio is analyzed from numerical simulation. Moreover, the formula of the Doppler current is given while the effect of the positional relation between reference beam and signal beam on Doppler current is analyzed. The theoretical analysis and simulation shows that the signal-to-noise ratio is an increasing function of light intensity of the reference beam, but when it reach a certain value, the signal-to-noise ratio increases slowly and is close to ηIs/(hνΔf ). It can reach the maximum value 0.7ηPs/(hνΔf ) when the Airy disk of two beams is nearly equal. The value of the Doppler current has a great correlation with the angle deviation of two beams when the two beams are non-parallel, whereas it has non-correlation with the incident angle of the beams when the two beams are parallel..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 36, Issue 6, 46 (2009)
A New Scheme for Pulse Integration of Direct Detection Radars
DUAN Jun-qi, HE Zi-shu, and YAN Ji-hong
Pulse compression can be performed in direct detection radars by using a newly proposed stepped time intervals coding pulse train and corresponding correlation algorithm. At the receiver end, the envelop-detected signal is processed through a modified cross-correlation algorithm which removes all the range false peaks,Pulse compression can be performed in direct detection radars by using a newly proposed stepped time intervals coding pulse train and corresponding correlation algorithm. At the receiver end, the envelop-detected signal is processed through a modified cross-correlation algorithm which removes all the range false peaks, leading to a perfect range sidelobe performance. Simulation results demonstrate the validity of the new approach. Furthermore, the approach is easy to be implemented and compatible to the conventional radars. It can be used in direct detection radars where Doppler information is not required or the radars which are difficult to provide coherence, such as short pulse laser radar (also called lidar) and ultra-wide band impulse radar. The proposed approach can also be applied to the upgrade of conventional non-coherent radars..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 36, Issue 6, 57 (2009)
Research of Alt-alt Photoelectric Telescope Sighting Error Measurement
HAN Xue-bing, ZHANG Jing-xu, WANG Zhi, ZHAO Jin-yu, ZHAO Yong-zhi, and WU Xiao-xia
In order to improve the accuracy of alt-alt photoelectric telescope, and meet the requirements of technology index, the theory and measurement of sighting error were discussed based on the measuring theory of alt-az telescope. Two programs of sighting error measurement were generated. The researching telescope can not In order to improve the accuracy of alt-alt photoelectric telescope, and meet the requirements of technology index, the theory and measurement of sighting error were discussed based on the measuring theory of alt-az telescope. Two programs of sighting error measurement were generated. The researching telescope can not work in reversed position of telescope. Sighting error was measured. The result is 4′1″ and the standard deviation of this method is 9″. Compared with the result of basic parameter model regression, it is found out that the measurement result contains the sighting axis deviation (1′4″, 2′4″) because of gravity deformation. A simultaneous determination measurement method for gravity deformation deviation and sighting error is proposed..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 36, Issue 6, 63 (2009)
Inversion Algorithm of Field Laser Particle Size Analyzer Based on Improved R-R Distribution
LIU Qi-hai, LIN Yu-chi, and YU Lian-sheng
For the inversion algorithm of field particle size distribution, a new method was proposed with the improved R-R distribution in the dependent model algorithm．Multi-group size parameters (X) and distribution parameters (N) were set simultaneously, and then their target functions (fitting errors) were inversed by multi-For the inversion algorithm of field particle size distribution, a new method was proposed with the improved R-R distribution in the dependent model algorithm．Multi-group size parameters (X) and distribution parameters (N) were set simultaneously, and then their target functions (fitting errors) were inversed by multi-threads technology. When the minimum fitting errors were found, it was considered that the particle size distribution function was an R-R distribution with corresponding X and N parameters. The experiments of field laser particle size analyzer illustrated that it took no more than one minute averagely in each inversion if using 5 threads. The method has advantages of simplicity，high accuracy, repeatability and rapidity，and can meet the needs of field particle size real-time measurement..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 36, Issue 6, 68 (2009)
Research of High precision Optical Fiber Delay Line
QIU Zhi-cheng, SHI Shuang-jin, and QIU Qi
Based on optical switch and fiber, the topologic structure of optical fiber delay line was designed. The influence of errors caused by optical fiber connection and the optical switch on precision of optical fiber delay line was analyzed. In order to design the optical fiber delay line of high precision, the method was Based on optical switch and fiber, the topologic structure of optical fiber delay line was designed. The influence of errors caused by optical fiber connection and the optical switch on precision of optical fiber delay line was analyzed. In order to design the optical fiber delay line of high precision, the method was found to reduce the error caused by optical switch. Optimal topologic structure was adopted, the software MATLAB was used to figure out all the results and the best structure would be found. The simulation result shows that, when the error of optical switch is less than 1 ps, the precision of optical fiber delay line is below 2 ps. Magneto optical switches and single-mode fiber were used to build 5bit optical fiber delay line. Experimental measuring results show that, when the step length is 100ps, the precision of the fiber delay line is better than 2.98 ps..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 36, Issue 6, 72 (2009)
Optical Radiative Properties of Pr3+-doped Polymer Optical Fiber
JIANG Cui-hua, ZHENG Zhi-qiang, FENG Zhuo-hong, XU Lin-lin, LI Xiao-yan, KONG Ling-kai, and MING Hai
A Pr-chelate-doped Polymer Optical Fiber (POF) is fabricated．Absorption and emission spectra of Pr3+ ions in Pr(DBM)3Phen-doped Polymethyl Methacrylate (PMMA) have been investigated．Based on modifed Judd-Ofelt theory, the intensity parameters of Pr3+ in PMMA are calculated to be Ω2=46.334×10-20 cm2，Ω4=18.897×A Pr-chelate-doped Polymer Optical Fiber (POF) is fabricated．Absorption and emission spectra of Pr3+ ions in Pr(DBM)3Phen-doped Polymethyl Methacrylate (PMMA) have been investigated．Based on modifed Judd-Ofelt theory, the intensity parameters of Pr3+ in PMMA are calculated to be Ω2=46.334×10-20 cm2，Ω4=18.897×10-20 cm2，Ω6=1.610×10-20 cm2. The intensity parameters are used to calculate the radiative lifetimes of 3P0 and 1D2 levels, the radiative transition rates and the fluorescence branch rations β. At the same time, the stimulated emission cross-sections σij (3P0→3F2, 1D2→3H4) are calculated. Analysis reveals that Pr (DBM)3 Phen-doped PMMA is promising for use in polymer optical fiber amplifier and laser..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 36, Issue 6, 76 (2009)
Relative Self-calibration of Large Frame Digital Camera
CUI Hong-xia, LIN Zong-jian, MENG Wen-Li, and HONG Zhi-Gang
To overcome the disadvantages of single non-metric camera with small format and short baseline, a composite camera was developed with the combination of four individual non-metric digital cameras. The large frame composite camera was able to meet low altitude photogrammetric applications with high accuracy and efficienTo overcome the disadvantages of single non-metric camera with small format and short baseline, a composite camera was developed with the combination of four individual non-metric digital cameras. The large frame composite camera was able to meet low altitude photogrammetric applications with high accuracy and efficiency. Since small movements of one camera against the other cannot be avoided due to a simple and low-cost structure, a relative self-calibration method was proposed to make up error derived from deformation of mechanical structure based on tie points in the overlapping areas of each two sub images. Analysis of factors influencing mapping accuracy was given based on the mosaic model used to project the images of the individual cameras to a single virtual image. Experiments indicate that the relative self-calibration method corrects small deformation of mechanical structure feasibly and the mosaic images meet the needed accuracy..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 36, Issue 6, 81 (2009)
Snakes Model of Integration Fuzzy Feature for Texture Image Segmentation
SHI Cheng-xian, WU Jian-cheng, ZHAO Zhi-xin, and FEI Zhong-hua
The amplitude spectrum of high frequency is taken as feature vector of texture via local one dimension Fourier transform of image. The fuzzy feature vector is defined by using feature vector with membership function. The fuzzy feature vector is integrated with Snakes model. The improved Snakes model makes the active coThe amplitude spectrum of high frequency is taken as feature vector of texture via local one dimension Fourier transform of image. The fuzzy feature vector is defined by using feature vector with membership function. The fuzzy feature vector is integrated with Snakes model. The improved Snakes model makes the active contour curve move under the interaction of curve internal force, image gradient force and normal force of curve. The module of normal force depends on feature vector membership degree. Experimental results show that the new model can segment the image texture effectively, and Snakes model integrated with fuzzy feature can extend the field of image segmentation..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 36, Issue 6, 86 (2009)
An Adaptive Digital Image Watermarking Algorithm Based on Binary Discrete Operation
ZHOU Ya-xun, GAI Na, and JIN Wei
An adaptive digital image watermarking algorithm based on binary discrete operation was proposed in the wavelet transform domain. At first, the wavelet approximation sub-image of the original image was decomposed into blocks and classified by using the human visual masking characteristics. Then, the blocks with best abAn adaptive digital image watermarking algorithm based on binary discrete operation was proposed in the wavelet transform domain. At first, the wavelet approximation sub-image of the original image was decomposed into blocks and classified by using the human visual masking characteristics. Then, the blocks with best abundant texture information were selected adaptively according to the size of the pseudo-random sequence watermark, and the watermark was embedded by adjusting these block coefficients based on the binary discrete operation. The original image was not required for detecting the watermark. As the watermarking embedding and detection is based on the binary discrete operation, the embedded digital watermark with the proposed algorithm is robust enough against the commonly used image processing techniques. Moreover, the embedding watermark is invisible..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 36, Issue 6, 91 (2009)
A Novel Edge-parameter Analysis Approach of the Blur Identification Based on the Single Threshold PCNN
HE Jin-ping, GAO Kun, and NI Guo-qiang
A novel edge-parameter analysis method of the blur’ identification based on Pulse Coupled Neural Networks (PCNN) model is proposed for image de-blurring application, which is suitable for the identification of the horizontal linear motion blur. This new identification method uses the improved single-threshold PCNN modeA novel edge-parameter analysis method of the blur’ identification based on Pulse Coupled Neural Networks (PCNN) model is proposed for image de-blurring application, which is suitable for the identification of the horizontal linear motion blur. This new identification method uses the improved single-threshold PCNN model and the normalized local entropy transformation to form a novel edge factor and extract edge and texture information from the blurred image. From the edge-parameter curve caused by the edge factor and the uniform linear motion parameter, the displacement parameter can be recognized accurately. The experimental results obtained from the different images and the same image with the different resolution show that the new algorithm is very effective and the curve performs quite stably. The identification displacement can ranges from 4 to 30 pixels..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 36, Issue 6, 97 (2009)
Local Invariant Feature Extraction Base on Salient Measurement of Second Moment Matrix
HU Jun-hua, XU Shou-shi, CHEN Hai-ling, and ZHANG Zhen
Inspired by image salient area detection model, A model for extracting local invariant feature is proposed based on salient measurement of local second moment matrix. The extraction is divided into two stages: The first one is the salient extent estimation of a local feature with analysis of the local image patch’s aniInspired by image salient area detection model, A model for extracting local invariant feature is proposed based on salient measurement of local second moment matrix. The extraction is divided into two stages: The first one is the salient extent estimation of a local feature with analysis of the local image patch’s anisotropy in image scale space. The second one is to direct the feature extraction process according to the extent of local information saliency and to create local salient feature descriptor with more accurate location match and a larger scale span. The experimental results with many real images show that the algorithm is effective and feasible..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 36, Issue 6, 103 (2009)
Multi-focus Image Fusion Based on Particle Swarm Optimization
LI Shuang, LIN Li-yu, and CHEN Rong-yuan
To solve the problems that the fusion rule in available image fusion methods can not be adjusted adaptively according to successive application, and the advantages of different fusion methods can not be integrated, a new image fusion method is proposed based on particle swarm optimization. Firstly, the DBSS (2, 2) discTo solve the problems that the fusion rule in available image fusion methods can not be adjusted adaptively according to successive application, and the advantages of different fusion methods can not be integrated, a new image fusion method is proposed based on particle swarm optimization. Firstly, the DBSS (2, 2) discrete wavelet transform and gradient pyramid fused images are used to create images as initial particles. Then, according to the requirements of successive application, the object function is constructed by the weighted sum of several image quality assessment criteria. Finally, according to object function, the fused image is obtained by particle swarm optimization. Two sets of images are assessed from visual inspection and quantitative evaluation (standard deviation, average gradient, entropy, spatial frequency, correlation coefficient and mean root cross entropy) to validate the feasibility of proposed method..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 36, Issue 6, 109 (2009)
An Improved Image Restoration Method Based on APEX Method
WANG Hui, and JIANG Ping
During the course of the image restoration degenerated by the Gauss (G) class Point Spread Function (PSF), an improved image restoration algorithm is proposed based on frequency spectrum characteristic of the blur image. According to the frequency spectrum information, the algorithm improves the course of estimation PSDuring the course of the image restoration degenerated by the Gauss (G) class Point Spread Function (PSF), an improved image restoration algorithm is proposed based on frequency spectrum characteristic of the blur image. According to the frequency spectrum information, the algorithm improves the course of estimation PSF by utilizing the basic principle of the APEX method. The main direction of the frequency spectrum of the blur image is fitted by the weighted least squares algorithm. The PSF is estimated by using the main direction data of frequency spectrum of the blur image, so more available data will be obtained for the PSF estimation, which reduces the error of the PSF estimation. The method is tested by the simulated blur image and the captured real blur image, and it is evaluated by the subjective vision and the Peak Signal-to-noise Ratio (PSNR). The experiment results indicate that, compared with the method using the frequency-spectrum data of non-main direction data, the improved method ameliorates the restoration effect of the blur image..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 36, Issue 6, 115 (2009)
Active Optics Experiment System with Thin-mirror
LI Hong-zhuang, WANG Jian-li, LIN Xu-dong, LIU Xin-yue, CHEN Bao-gang, and HAN Chang-yuan
Active optics experiment was carried out with a 400 mm diameter, 12 mm thickness mirror. The support system of the mirror includes 12 active support points and 3 fixed support points. The active support was implemented by force actuator, which was composed of piezoelectric ceramics actuator and loadcell. The active supActive optics experiment was carried out with a 400 mm diameter, 12 mm thickness mirror. The support system of the mirror includes 12 active support points and 3 fixed support points. The active support was implemented by force actuator, which was composed of piezoelectric ceramics actuator and loadcell. The active support points were used for controlling the surface of the test mirror, and the fixed points were used for positioning the mirror. The mirror surface was tested by Shack- Hartmann wavefront sensor, the active corrective force was calculated through damp least square method, and the process of exerting force of the actuator was controlled by PID algorithm. The initial surface error is 1.16λ (λ =632.8 nm) RMS. After active correction, the surface error is 0.07λ RMS，which is better than 0.1λ of surface quality after polishing..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 36, Issue 6, 120 (2009)
Measurement of Flat Wavefront by Sub-aperture Stitching Interferometry
WANG Li-hua, WU Shi-bin, HOU Xi, KUANG Long, and CAO Xue-dong
The principle of stitching interferometry for testing the flat wavefront was introduced. Error averaging method was used in the experimental data processing, which could reduce error accumulation and improve the precision. Based on the algorithm, we carried out experiments, tested the telescope optical system simulatedThe principle of stitching interferometry for testing the flat wavefront was introduced. Error averaging method was used in the experimental data processing, which could reduce error accumulation and improve the precision. Based on the algorithm, we carried out experiments, tested the telescope optical system simulated by Zemax software, and used 100 mm small aperture interferometer to measure the 200 mm flat mirror. Compared the stitching results with the directly measured full aperture, the Peak-to-valley (PV) and Root Mean Square (RMS) of the wavefront phase distribution residua are 0.015 1λ and 0.001 6λ, 0.055 9λ and 0.000 4λ respectively. It was proved that the model and method are not only accurate and feasible to test the optical mirrors, but also can be applied to test optical system..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 36, Issue 6, 126 (2009)
Experimental System Research of Fiber Acoustic Sensor
LI Rui, XIAO Wen, YAO Dong, and XU Bing-shi
In order to assemble the fiber acoustic sensor automatically and accurately, an experimental system composed of intensity collection, sensitivity analysis and distance location was proposed. At first, by collecting the received intensity data at different operating distances, the characteristic curve of sensor was obtaIn order to assemble the fiber acoustic sensor automatically and accurately, an experimental system composed of intensity collection, sensitivity analysis and distance location was proposed. At first, by collecting the received intensity data at different operating distances, the characteristic curve of sensor was obtained. Then, these intensity data were analyzed to get the sensitivity characteristics of sensor, such as the sensitivity and linear operating range. Meanwhile, the optimum operating distance where the sensor has the best performance was confirmed. A feedback control signal was sent back to adjust and locate the optimum operating distance. A sensor with parallel fibers was set up by the proposed system. Experimental result indicates that the sensitivity of sensor is 16 mV/Pa at the optimum operating distance of 160 μm..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 36, Issue 6, 131 (2009)
Design of the High Speed High Sensitivity Fiber Transmission EMCCD Camera
YANG Shao-hua, GUO Ming-an, LI Bin-kang, CHEN Yan-li, SUN Feng-rong, and XIA Jing-tao
Since high frame rate camera faces the challenge of high sensitivity and real-time transmission, EMCCD sensor is applied to improve its sensitivity, and fiber communication and USB technology are used to solve long-distance acquisition problem. This paper introduces the design of a high speed camera based on a new EMCCSince high frame rate camera faces the challenge of high sensitivity and real-time transmission, EMCCD sensor is applied to improve its sensitivity, and fiber communication and USB technology are used to solve long-distance acquisition problem. This paper introduces the design of a high speed camera based on a new EMCCD image sensor CCD60. The logic control sequence of the CCD and the simultaneous processing control sequence of video signal are designed based on a CPLD. Firstly, DS0026 clock driver ICs are used for the standard clocks and discrete circuit is used for fast pulsed high-voltage (multiplication) clock. Then, the CCD video signal is digitized by a special circuit with CDS function. The high frame rate image data is transmitted to long-distance acquisition hardware through fiber cables. Finally, The USB port image data acquisition hardware is designed which allows the images from the EMCCD to be acquired in real time. The resolution of the system is 128×128. In low-light-level conditions, the system is capable of operating at 1000 frame/s..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 36, Issue 6, 135 (2009)
Design and Implementation of Photoelectric Sensor for Detecting Color Code Used in Automatic Register Controller
LI Na-na, AN Zhi-yong, and CHEN Guang-qiu
For the sake of solving the color mark detecting problem of overprinting error information in gravure printing, an optical module of detecting color marks is designed and realized based on the principle that the reflected light energy absorption is different when various colored bars are irradiated by a white light souFor the sake of solving the color mark detecting problem of overprinting error information in gravure printing, an optical module of detecting color marks is designed and realized based on the principle that the reflected light energy absorption is different when various colored bars are irradiated by a white light source. In addition, a sort of glass slice with one face possessing semitransparent capacity, the half reflectivity and the function of a photocell’s photovoltaic conversion are utilized. As a result of weakness and non-digital of output signal, an output signal is magnified and transformed. The experiment result shows that the sensor has many good features, such as an uncomplicated structure, far detecting distance((10±2) mm), little facula radius(Φ1.5 mm), high sensitivity, fast response speed(0.2 ms), high stability and reliability, etc..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 36, Issue 6, 141 (2009)
Effect of Temperature on Surface Plasmon Resonance Sensor
Lü Hui, MA Xiao-hong, and ZHAO Hua-feng
A Surface Plasmon Resonance (SPR) sensor is tested precisely with the prism angular detection approach. The working principle about the temperature effect on SPR is theoretically analyzed, and then the testing system is designed according to the principle. The thermal effect on the resonance angle of SPR was investigatA Surface Plasmon Resonance (SPR) sensor is tested precisely with the prism angular detection approach. The working principle about the temperature effect on SPR is theoretically analyzed, and then the testing system is designed according to the principle. The thermal effect on the resonance angle of SPR was investigated based on angular detection. The experiment result proves that the SPR angle descends with the increase of temperature. Moreover, the slope is about -7.843×10-3/℃. It shows that the temperature control is important in the practical application of the SPR sensor..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 36, Issue 6, 146 (2009)
Inspecting System for Auto-loading of Bulk Cargo
HE Jun-ji, and SHI Li
It is difficult to load a cargo ship automatically at present because there is no reliable, precise and practical method for measuring the status of cargo loading machinery. Therefore, an approach, as well as a device was proposed based on laser scanner, which could measure multiple real-time parameters of the status oIt is difficult to load a cargo ship automatically at present because there is no reliable, precise and practical method for measuring the status of cargo loading machinery. Therefore, an approach, as well as a device was proposed based on laser scanner, which could measure multiple real-time parameters of the status of cargo loading machinery. Based on the principle of laser range measurement and applying line fitting algorithm to the data gotten from a laser scanner, the method could measure the parameters precisely in real time, such as the position of the chute of a cargo loading machinery relative to the cabin of the ship being loaded as well as the cargo below, the height of cargo in a cabin and the obliquity of a ship. The measuring system has been tested in the process of cargo auto-loading in a cargo terminal. It is proved that the system is precise, reliable and effective..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 36, Issue 6, 562 (2009)
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