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Issue 5 ， 2018
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Three hundred and fourty-nine unit adaptive optical wavefront processor
Abstract：In order to meet the correction frequency and imaging quality requirements of adaptive optics systems for large ground-based high-resolution imaging telescopes, a 349-unit wavefront processor was designed, which realized a wavefront correction frequency of 1 500 Hz. The design of a real-time wavefront processor was proposed whose main components were a control computer, a FPGA wavefront slope processor, a GPU matrix multiplication handler and a modularization D/A converter. A closed-loop calibration result Keywords：adaptive optics;wavefront processor;ground-based high-aperture telescope;deformable mirror- 119
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Published：2020-08-13 -
Review on three-dimensional surface measurements of specular objects based on full-field fringe reflection
Abstract：With the fast development of integrated circuits, the automotive industry, advanced manufacturing, and astronomy, fringe reflection profilometry (FRP, also called deflectometry) is widely used to measure the three-dimensional (3D) shapes of specular surfaces. FRP reconstructs the 3D shape of an object by calculating the local gradient or depth information of the specular surface using the phase information in the reflected fringe patterns. In order to gain a complete understanding of the recent developments Keywords：three-dimensional surface measurement;fringe reflection profilometry (FRP);specular objects;gradient integration- 154
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Published：2020-08-13 -
Control strategy for distortion elimination of long-wave infrared camera on-orbit scanning imaging
Abstract：The control technology of a distortion control system for zoom scanning imaging was investigated to eliminate ground distortion of a long wave infrared camera on-orbit scanning imaging. A high-precision multi motor position synchronization algorithm was proposed taking the multi motor position synchronization of zoom scanning control into consideration. The synchronous positions of the zoom group motor and the compensating group motor at each point of the scanning time were set according to the design princ Keywords：long-wave infrared camera;zoom scanning;distortion elimination;multi-motor position synchronization- 114
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- 14
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Published：2020-08-13 -
High-precision dynamic celestial simulator with sub-pixel display technology
Abstract：For general attitude sensors, there is a deviation between the actual measurement results and design precision of non-on-orbit calibration equipment. In addition, they lack the simulation function for the target celestial body's characteristics. In this work, we combined a polarization splitting prism and semi-reversing semi-transparent prism to complete liquid crystal on silicon (LCOS) optical splicing manner. With sub-pixel display technology, in which many pixels were used to express one feature point, a Keywords：optical system design;celestial simulation;contrast of LCOS splicing;sub-pixel display technology- 79
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Published：2020-08-13 -
Research of scanning slit with minimal penumbra of blade's edge in lithography
Abstract：Scanning slit is an important element for controlling exposure dose in step-and-scan lithography. Too large a penumbra of the blade's edge in scanning slit could affect the exposure performance. Firstly, according to the illumination principle of a step-and-scan lithography, the calculation formula of the penumbra of the blade's edge at the reticle plane was derived by analyzing the relationship between the intensity distribution of the reticle and the thickness and location of the blades in the scanning sl Keywords：photolithography;step-and-scan;scanning slit;synchronization;penumbra of blade's edge- 126
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- 19
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Published：2020-08-13 -
Design of optical system for stereo imaging fundus camera
Abstract：A nonmydriatic optical system for stereo imaging fundus camera was designed in this work. It could simultaneously capture two images of the same fundus retinal region from different angles, and could enable three-dimensional reconstruction of the fundus. It comprised an imaging system and a lighting system. In the imaging system, the Gullstrand-Le Grand eye model was used to simulate the normal human eye, and the principle of stereomicroscope was employed to design the splitting optical system. In the light Keywords：optical design;fundus camera;stereo imaging;eye model- 82
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Published：2020-08-13 -
Study on strain measurement accuracy of optical extensometers based on digital image correlation
Abstract：Although optical extensometers based on Digital Image Correlation (DIC) method have widespread applications in strain measurement, there is a lack of systematic research on the strain measurement accuracy. For the uniaxial tensile test, testing equipment including the traditional 2D-DIC optical extensometer, three-dimensional digital image correlation (3D-DIC) optical extensometer, 2D-DIC optical extensometer equipped with dual-reflector imaging capability, and strain gauge were employed to measure the stra Keywords：digital image correlation;optical extensometer;dual-reflector imaging;strain measurement accuracy;out-of-plane displacement- 104
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- 7
Published：2020-08-13
Modern Applied Optics
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Rapid start-up control of high
Q -factor MEMS gyroscopeAbstract：The control method of the drive axis was investigated with the goal of rapid startup of the MEMS gyroscope with a high Q-factor. The change rate of the vibration phase of the high Q-factor resonator with frequency was analyzed, and the reason for the long starting time of the phase-locked loop scheme in addition to its sensitivity to the initial frequency deviation was elucidated. The variation rule of the amplitude at the initial stage of the self-excited oscillation scheme with time was deduced by using t Keywords：MEMS gyroscope;startup;phase-locked loop;self-exited osillation- 118
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Published：2020-08-13 -
Research on status and analysis of precise cable drive technology
Abstract：A precise cable drive system is a flexible friction transmission method that utilizes the power transmitted from drive capstans to a driven pulley through a proper preloaded transmission medium. It has many advantages, such as flexible layout and high precision, besides being lightweight. It is widely used in many dexterous precise electromechanical devices and servomechanisms. The progress in the applicability of the precise cable drive is summarized in the aspects of precision pointing mechanism, harmonious robot, haptic interface mechanism, running robot, dexterous hand and endoscopic surgery. Next, the urgent issues of the basic theory and application research are dealt with, including studies on transmission mechanism, applied studies on servo systems, and engineering design methods for typical applications. Eventually, some suggestions regarding further research on theory analysis and engineering design technology of the precise cable drive system have been put forward.Keywords：precise cable drive;application progress;transmission mechanism;applied technology;engineering design method- 106
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Published：2020-08-13 -
Pulse electrochemical machining of micro channel arrays in discrete fields and domains
Abstract：A method of pulse electrochemical machining in discrete fields and domains was introduced to solve the problems in microchannel arrays machining on difficult-to-cut metal surface. This method has the characteristics of processing microchannels with high surface quality and a non-penetrating structure. The machining zone of each channel was separated by the specially designed fence-like template made of nonconductive material, and hence the electrolyte flow field and electric field are confined and improved, Keywords：electrochemical machining;difficult-to-cut metal;micro channel arrays;discrete fields and domains;fence-like template- 74
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Published：2020-08-13 -
Control of liquid-immersed submerged microsphere for super-resolution optical imaging
Abstract：Images with resolution beyond the diffraction limit can be achieved by combining conventional microscopy with a microsphere. In order to position the microsphere on the field of interest of the sample surface and to expand the observation area, a method to manipulate the microsphere by combining it with a multi-axis translation stage was proposed in this paper. Images were obtained by scanning the microsphere, which was positioned accurately by driving the translation stage with four degrees of freedom. The Keywords：super-resolution imaging;micro-manipulation;microsphere- 128
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Published：2020-08-13 -
Mixed-sensitivity-based robust control of secondary mirror adjustment mechanism for space telescopes
Abstract：Secondary mirror adjustment mechanisms are core elements of active optics used for the adjustment of space telescopes. For real-time rapid adjustments in orbit, great demands are put on their adjusting accuracy and dynamic characteristics. Because of nonlinearity, uncertainty, disturbances, and coupling of the system, sufficient control cannot be easily achieved by traditional methods based on intermixing PID systems and inverse kinematics. Focusing on this problem, an uncoupled electromechanical model was Keywords：space telescope;Stewart platform;active optics;robust H∞ control;mixed sensitivity- 95
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- 14
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Published：2020-08-13 -
Small precision motion platform based on stick-slip driving principle
Abstract：To realize precise actuation of micro/nano-manipulation systems, a type of nano-motion platform based on the stick-slip principle was designed. Flexure hinges, a mass block, and an elastic component were integrated as an independent stator base. The stator consisted of a stator base, a piezoelectric stack, and a ceramic ball installed in the base bottom. The vertical position of the end of the elastic component can be adjusted by rotating an adjustment screw to change the pre-pressure between the stator and Keywords：stick-slip driving;piezoelectric stack;platform;precision motion;mechanical analysis- 123
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Published：2020-08-13 -
Design and fabrication of passive MEMS pressure switch
Abstract：In order to overcome the shortcomings of traditional mechanical and electronic pressure switches, such as the production process is complex and it is difficult to integrate with the follow-up circuit, bulky and so on, the design and preparation of passive MEMS pressure switch were developed by using glass frit encapsulation technology with metal lead coverage in this paper. The overall structure of the passive MEMS pressure switch was designed to include the pressure sensitive film, the silicon island and t Keywords：Micro-Electro-Mechanical System (MEMS) pressure switch;structural design;wet etching;glass frit encapsulation technology- 72
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- 15
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Published：2020-08-13 -
Practical research on computer chip water cooling system with combined piezoelectric pump unit
Abstract：In order to improve the applicability, maintainability and the cooling efficiency of piezoelectric computer chip water cooling system, a computer chip water cooling system driven by combined piezoelectric pump was proposed. Initially, the output performance of the combined pump units in piezoelectric water-cooling system with different combinations (series/parallel), pump quantity and the relative position were tested and analyzed under 220 Vpp square wave. Subsequently, a research on water cooling efficien Keywords：piezoelectric pump;water cooling system;computer chip- 80
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Published：2020-08-13 -
Research of life test and design of system for satellite-borne infrared detector assembly
Abstract：The detector is the core component of the photoelectric conversion in the satellite-borne, and once launched, it is almost impossible for the maintenance, repair and replacement. Using The screened commercial infrared detector without life data has the risk. The service life of the thermoelectric cooler(TEC) is the weak link of the life of detector assembly, and its reliability has an important influence on the normal use of the detector. Therefore, it is important to study the life test of the infrared det Keywords：aerospace load;infrared detector;constant stress;fixed number truncation;life test;temperature cycle- 131
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Published：2020-08-13 -
Fabrication, testing and simulation of microneedle array based on X-ray lithography
Abstract：In order to improve the efficiency of transdermal drug dilivery and reduce the pain of traditional injection on the human body, the microneedle array is needed. In this paper, the fabrication technique for microneedle array was introduced. A microneedle array was obtained on a polymethylmethacrylate (PMMA) substrate by using two moving X-ray lithography and alignment X-ray exposure process using the synchrotron radiation source AURORA of Japanese Ritsumeikan University. A hollow microneedle array was fabric Keywords：transdermal drug dilivery;moving X-ray lithography;fixed X-ray lithography;microneedle array- 94
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- 12
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- 2
Published：2020-08-13
Micro/Nano Technology and Fine Mechanics
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Rapid start-up control of high Q-factor MEMS gyroscope
Abstract：The control method of the drive axis was investigated with the goal of rapid startup of the MEMS gyroscope with a high Q-factor. The change rate of the vibration phase of the high Q-factor resonator with frequency was analyzed, and the reason for the long starting time of the phase-locked loop scheme in addition to its sensitivity to the initial frequency deviation was elucidated. The variation rule of the amplitude at the initial stage of the self-excited oscillation scheme with time was deduced by using the averaging method. A control scheme that combines the self-exited oscillation loop and the phase-locked loop (SEOL-PLL) of the drive axis was proposed. The self-excited oscillation mode was used to quickly start the gyroscope, and then the phase-locked loop was used to maintain the accuracy and stability of the vibration frequency. In the experiment, when the initial frequency deviation of the PLL is less than ±10 Hz, the starting time of the gyroscope is 2 s. Whereas with the SEOL-PLL scheme, a frequency error of 0.01% is achieved in 0.3 s and an amplitude error of 0.1% is achieved in 0.4 s, as long as the initial frequency deviation is within ±1 000 Hz. The "SEOL-PLL" solution considerably reduces the start-up time and is insensitive to the initial frequency deviation of the gyroscope. It is therefore suitable for the mass production of MEMS gyroscope and has a good adaptability to ambient temperature change.Keywords：MEMS gyroscope;startup;phase-locked loop;self-exited osillation- 52
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Published：2020-08-13
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Anti-electromagnetic interference electrocardiogram monitoring system
Abstract：In order to realize the ECG monitoring under electromagnetic interference environment, an anti-EMI ECG monitoring system based on the optical modulator was proposed in this paper. Firstly, the calculation formula of output photocurrent was discussed, and the influence of half wave voltage and insertion loss on the sensitivity was analyzed. Secondly, the Lithium Niobate (LiNbO3) electro-optic crystal was used to establish experimental setup, and measure the ECG signals of five health subjects. Then the propo Keywords：Mach Zehnder interferometer;lithium niobate electro-optic crystal;wearable medical equipment;Electrocardiogram (ECG) signals monitoring;electromagnetic environment- 90
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Published：2020-08-13 -
Time-domain denoising based on photon-counting LiDAR
Abstract：For decreasing the effect of background noise, the traditional imaging method of laser radar requires take long time in accumulation sampling and generating statistical histogram of photon countingto obtain the depth estimation of target. A 3D time-domain denoising algorithm based on photon-counting laser radar was proposed in this paper. Combined with the Poisson statistical model, the method proposed did not need to generate photon counting statistic histogram but used the different distribution feature o Keywords：photon-counting laser radar;single-photon detector;3D imaging;time domain denoising- 126
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- 5
Published：2020-08-13 -
Image registration of polarimeters
Abstract：There are position errors between the images from each split optical path of the amplitude-division imaging polarimeters, image registration between the images from each split optical path is a precondition for polarized detection. In order to solve the problem that the features of the target are not obvious and difficult to extract, and that the change of gray scale of the image is large, a function of similarity measurement was proposed and it was suitable for the image registration of the amplitude-divis Keywords：imaging polarimeters;image registration;polarized information;similarity metric function;mutual information- 110
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Published：2020-08-13 -
Illumination compensation using Retinex model based on bright channel prior
Abstract：Aiming at the problem of image quality degradation caused by insufficient illumination, a retractive algorithm of bright channel was proposed to compensate the illumination intensity of the image. The algorithm assumed that the local constant light could initially satisfy the uniformity of illumination and was similar to the scene, and the bright channel operation was used to estimate the weight of the light component. The problem of blocking was usually solved by the local processing, but this would make t Keywords：retinex;bright channel;illumination compensation- 109
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- 5
Published：2020-08-13 -
Target extraction from LiDAR point cloud data using irregular geometry marked point process
Abstract：In order to realize the arbitrary shape object extraction from LiDAR point cloud data, a method based on irregular marked point process was proposed. Firstly, a random point process was defined on ground plan, in which random point positioned the object projection on the plan. Then the marks associating individual points were defined with a set of nodes to depict the shape of object on the ground plan. Assumed that the elevation values of ground points followed an independent and identical Gauss distributio Keywords：Marked Point Process (MPP);LiDAR point cloud data;Bayesian inference;Maximum A Posteriori (MAP);Reversible Jump Markov Chain Monte Carlo (RJMCMC)- 87
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Published：2020-08-13 -
Detection of low dose CT pulmonary nodules based on 3D convolution neural network
Abstract：To improve the detection rate of pulmonary nodules in early lung cancer screening, a low-dose CT pulmonary nodule detection algorithm based on 3D convolution neural network was presented. First, the multi-directional morphological filtering algorithm was used to preprocess low-dose sequence CT image. The improved 3D region growth algorithm combined with the convex hull algorithm was used for lung parenchymal segmentation. Then the 3D candidate nodules were routed and illuminated in order to solve the convol Keywords：lung cancer screening;three dimensional convolution neural network;ELCAP;lung nodule;imbalance- 163
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Published：2020-08-13 -
Automatic extraction of rotation axis line from 3D scanned point cloud of rotational symmetric object
Abstract：Measurement of solid rocket nozzle thrust line is one of a key technique in the field of spacecraft precise installation and is a representative application of rotation axis line extraction of rotational symmetric object. Given that the existing methods have the problems such as nonobjective, poor reliability and low adaptability, an automatic solution for rotation axis extraction from 3D scanned high density of point cloud data was proposed, in which all the surface points and their normal vectors were uti Keywords：rocket nozzle;thrust line;rotation axis;point cloud;normal vector- 106
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Published：2020-08-13 -
Three-dimentional reconstruction of semantic scene based on RGB-D map
Abstract：Reconstruction of 3D object is an important part in machine vision system, and the semantic understanding of 3D object is a core function for the machine vision system. In this paper, 3D restoration was combined with the semantic understanding of 3D object, a 3D semantic scene recovery network was proposed. The semantic classification and scene restoration of 3D scene were achieved only by using a single RGB-D map as input. Firstly, an end-to-end 3D convolution neural network was established. The input of t Keywords：machine vision;scene restoration;RGB-D map;semantic classification;convolution neural network- 64
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Published：2020-08-13 -
Infrared and visible image fusion using guided filter and convolutional sparse representation
Abstract：In order to solve the problem that the information from the source images is easy to interfere with each other which influences the quality of infrared and visible image fusion, a new image fusion method based on Guided filter, Gaussian filter and nonsubsampled directional filter bank was proposed. The low-frequency approximation components, strong edge components and high-frequency detail components were obtained by combining Guided and Gaussian filter. Then the high-frequency detail components were filter Keywords：image fusion;edge-preserving filter;guided filter;nonsubsampled directional filter bank;pulse coupled neural network;sum of modified laplacian- 113
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Published：2020-08-13 -
Micro-vision image adaptive enhancement and application based on raised cosine variable gain
Abstract：The micro-vision images captured by the CCD camera typically show low gray value, non-uniform illumination, large dynamic range, poor contrast and missed or unrecognized fine structure due to the coaxial light source and optical diffraction in micro-vision system. Based on the raised cosine and variable gain sub-band decomposition algorithm, a micro-vision image adaptive enhancement method was developed to improve the image quality in this work. First, on the basis of image characteristic, the original micr Keywords：micro-vision;image enhancement;non-uniform illumination;raised cosine;variable gain- 84
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Published：2020-08-13 -
A vehicle logo recognition algorithm based on the improved SIFT feature
Abstract：In order to reduce redundancy of detecting extreme point and various adverse effects of image change factors during using SIFT vehicle logo recognition algorithms. An improved SIFT algorithm based on edge constraint and global structure was proposed, it took advantages of the image moment invariant theory and the image edge detection algorithm to only detect edge regions of target image, eliminating extreme points that have nothing to do with vehicle logo recognition regions, and it divided each feature poi Keywords：vehicle logo recognition;SIFT feature;edge constraint;extreme point detection;Support Vector Machine (SVM)- 106
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Published：2020-08-13 -
Three-dimensional microscopic reconstruction of MEMS based on multi image fusion
Abstract：In order to realize the three-dimensional measurement of micro electro-mechanical systems (MEMS), it is usually necessary to use a microscope or an optical profilometer. However, the traditional method has problems such as low precision and high cost of detection equipment, and it cannot achieve good results for an MEMS structure with many fracture surfaces. A new method for 3D measurement and image processing was presented in this paper. Unlike the three-dimensional reconstruction measurement method of mul Keywords：Micro-electro-mechanical Systems (MEMS);3D measurement;microscope;focus measurement;haze removal algorithm- 113
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Published：2020-08-13
Information Sciences
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