Chinese Version Light学术出版中心
Latest Issue
Issue 5 ， 2019
-
Research progress of pixel-level integrated devices for spectral imaging
Abstract：The majority of the present spectral imaging systems couple traditional filters with photodetectors, which are too large and cannot be customized. The rapid advances in micro/nano-opto-electro-mechanical systems have provided effective solutions for the continuing miniaturization of spectral imaging systems. Based on plasmonics and optical metasurfaces, micro/nano color filters are capable of regulating light fields at the pixel level and thus have the potential to replace traditional filters and to be inte Keywords：spectral imaging;integrated optical devices;color filtering;optical metasurfaces- 158
- |
- 12
- |
- 6
Published：2020-08-13 -
Development of inner-surface profile measurement system for ICF capsule
Abstract：Considering the urgent demand for high-precision and nondestructive measurements of a Inertial Confinement Fusion (ICF) capsule, an inner-surface profile measurement system for an ICF capsule was developed in this study. First, the system used a Least Square Circle (LSC) algorithm to calculate the capsule′s eccentricity and adjusts it automatically and quickly using the eccentricity adjustment table. The system then controlled via software an air-bearing shaft to drive the capsule rotation, and it used the Keywords：confocal measurement;Inertial Confinement Fusion(ICF) capsule;inner profile;automatic eccentric adjustment- 132
- |
- 12
- |
- 7
Published：2020-08-13 -
Process parameters and thermal physical properties of W-Ni-Cu composite fabricated using selective laser melting
Abstract：To investigate the process and thermal physical performance of W-Ni-Cu manufactured using the Selective Laser Melting (SLM) technique, an experiment of four variables was conducted to study the influence of laser power, scanning speed, length of the scanning line, and overlap rate on the density. Scanning electron microscopy as well as a thermal analyzer, differential scanning calorimeter, and thermal-mechanical analyzer were used to study the microstructure, thermal conductivity, and thermal expansion. The Keywords：selective laser melting;W-Ni-Cu alloy;process parameter;microstructure;thermal conductivity;thermal expansion coefficient- 118
- |
- 16
- |
- 0
Published：2020-08-13 -
Effectiveness evaluation system for anti cat′s eye detection technology using optoelectronic target
Abstract：Anti cat′s eye detection is currently an active area of research in the optoelectronics countermeasure field. The basis of this investigation was the objective evaluation technology of effectiveness for quantification purposes. An effectiveness evaluation technology based on cat′s eye echo image processing was proposed. The detectability of a target was evaluated based on the change of the image centroid in a calculation window. Moreover, quantitative evaluation of anti-cat′s-eye detection technology was re Keywords：active photodetection;anti cat′s eye detection;echo image;image centroid- 106
- |
- 12
- |
- 1
Published：2020-08-13 -
Precision measurement of X-ray optical thickness in capsules
Abstract：To precisely measure the x-ray optical thickness of laser inertial confinement fusion capsules, an experimental apparatus based on a precision gas spindle and fiber array detectors is developed. By utilizing the chromatic confocal spectrum and optical microscopy, the problems of fine adjustment of the gas spindle and alignment of the X-ray optical path are solved successfully. The obtained x-ray optical thickness data provide information about local defects, surface quality, distribution of thickness, and composition. The results of the systematic stability demonstrate that the x-ray optical thickness of capsules can be measured precisely with a maximum repeatability deviation of 0.01% and a lateral resolution of 100 μm.Keywords：optical measurement;laser fusion;X-ray optical thickness;light path calibration;capsule- 98
- |
- 0
- |
- 3
Published：2020-08-13 -
Design of laser schlieren test system for mine gas/air premixed gas deflagration
Abstract：To obtain accurate internal micro-structure information related to mine gas/air premixed gas deflagration flow fields, the evolutionary process of deflagration flow fields and the mechanism involved in inert medium flame retardant inhibition from the perspective of elementary reactions must be understood. A high-speed laser schlieren measurement system is constructed for the mesoscale shock pipeline. Due to the geometric space constraints in the laboratory, a design scheme of a Z-shaped optical path for the Keywords：laser schlieren;shock tube;optical path design;gas deflagration;flame retardant and explosion suppression- 108
- |
- 0
- |
- 4
Published：2020-08-13 -
Bending deformation of optical fiber sensing and shape reconstruction of soft pneumatic driver
Abstract：To solve the flexible sensing measurement problem of flexural bending of soft pneumatic drivers, a method of curvature measurement and shape reconstruction by embedding fiber grating into a strain limiting layer for a soft pneumatic driver was proposed. First, the relationship between the spectral characteristics of the fiber grating and bending curvature of the strain limiting layer were theoretically analyzed. Then, a device that performs soft sensing, demodulation, and curvature calibration based on the Keywords：optical sensing;shape sensing;fiber Bragg grating;curvature measurement;pneumatic driver;polyimide film- 267
- |
- 62
- |
- 8
Published：2020-08-13 -
Hundred-Hertz nonchain HF laser with long operation period based on initiated discharge
Abstract：The aim of this investigation was to achieve stable and high-energy repetitive pulsed mid-infrared HF laser operation. A systemic study of pulsed energy stability based on a compact, closed-circle, electric-discharge nonchain HF chemical laser with a repetition frequency of 100 Hz was performed. Initially, the three main factors that influence pulse energy stability in an electric-discharge nonchain HF chemical laser were identified based on chemical reaction kinetics and experimental results without gas fl Keywords：mid-infrared laser;chemical laser;HF laser;discharge initiation;energy stability- 67
- |
- 13
- |
- 0
Published：2020-08-13 -
Detection of heavy metal Pb in soil by filament-nanosecond laser induced breakdown spectroscopy
Abstract：In this study, quantitative analysis of heavy metal lead in soil was conducted by femtosecond laser-filament-laser-induced breakdown spectroscopy (Filament-ns DP-LIBS). First, a femtosecond laser plasma wire was used to ablate the lead-containing soil sample, and a low-density soil particle source was sprayed outward. Then, following interpulse delay time Δ t, another nanosecond laser beam was used to re-ablate the low-density soil particle source to enhance spectral intensity, compress spectral line width, Keywords：filament-nanosecond laser induced breakdown spectroscopy;spectral resolution;soil heavy metal pollution;Pb element- 129
- |
- 22
- |
- 6
Published：2020-08-13
Modern Applied Optics
-
Research Progresses of Pixel-level Integrated Devices for Spectral Imaging
Abstract：The majority of the present spectral imaging systems couple traditional filters with photodetectors, which are too large and cannot be customized. The rapid advances in micro/nanooptoelectromechanical systems have provided effective solutions for the continuing miniaturization of spectral imaging systems. Based on plasmonics and optical metasurfaces, micro/nano color filters are capable of regulating light fields at the pixel level and thus have the potential to replace traditional filters and to be integrated with imaging systems on chips. In recent years, microspectral imaging systems integrated with dynamic or static filters have come to the forefront of new research and are enabling the development of new methods of spectral imaging. However, complete understanding of the fundamental theories of plasmonic filters remains elusive. In addition, a host of problems exist in terms of device performance, manufacturing cost, and assembly processes. In this review, we present the research progress of pixellevel integrated microdevices for spectral imaging, including micro/nano color filters, integrated manufacturing of filters and imagers, and assembly techniques of microspectral imaging systems. We also summarize the limitations and discuss the development trends of microspectral imaging systems.Keywords：spectral imaging;integrated optical devices;color filtering;optical metasurfaces- 100
- |
- 15
- |
- 6
Published：2020-08-13 -
Development of inner-surface profile measurement system for ICF capsule
Abstract：Considering the urgent demand for highprecision and nondestructive measurements of a Inertial Confinement Fusion (ICF) capsule, an innersurface profile measurement system for an ICF capsule was developed in this study. First, the system used a Least Square Circle (LSC) algorithm to calculate the capsule′s eccentricity and adjusts it automatically and quickly using the eccentricity adjustment table. The system then controlled via software an airbearing shaft to drive the capsule rotation, and it used the zerocrossing point of the axial response curve of a laser differential confocal sensor and a ray tracing algorithm to calculate the geometric position of each sampling point on the capsule′s innersurface profile. Finally, the roundness value of the inner profile was evaluated using LSC. Experimental results show that the eccentricity adjustment time can reach 22 s, and the inner profile measurement time can reach 10, 20, and 40 s, which correspond to the sampling points of 1 024, 2 048, and 4 096, respectively. In addition, the standard deviation of the inner profile roundness is shown to be as high as 19 nm (1 024 points). The system realizes an automatic rapid adjustment of the capsule′s eccentricity and a highprecision, nondestructive, rapid, and automatic measurement of the capsule′s inner profile.Keywords：confocal measurement;ICF capsule;inner profile;automatic eccentric adjustment- 87
- |
- 20
- |
- 7
Published：2020-08-13 -
Effectiveness evaluation system for anti cat′s eye detection technology using optoelectronic target
Abstract：Anti cat′s eye detection is currently an active area of research in the optoelectronics countermeasure field. The basis of this investigation was the objective evaluation technology of effectiveness for quantification purposes. An effectiveness evaluation technology based on cat′s eye echo image processing was proposed. The detectability of a target was evaluated based on the change of the image centroid in a calculation window. Moreover, quantitative evaluation of anticat′seye detection technology was realized by contrastive measurements of key parameters such as the maximum detection range & minimum power of the illuminating laser in the same range. The principles of the evaluation system were discussed. In addition, a prototype was designed and tested in an outfield using two sighting telescopes as targets both before and after anticat′seye detection procedure. The results indicate that when the test distance changes from 500 m to 1 km, the decrease in the minimum illumination power is 1.5%. When the illumination laser power changes from 500 mW to 300 mW, there is an increase in the maximum detection distance of 1.8%. This implies that the proposed evaluation technology are consistent under different experimental conditions, and could be used to objectively and accurately quantify the effectiveness of the anticat′seye detection technology. It also has the potential to support research in related fields.Keywords：active photodetection;anti cat′s eye detection;echo image;image centroid- 68
- |
- 10
- |
- 1
Published：2020-08-13 -
Design of laser schlieren test system for mine gas / air premixed gas deflagration research
Abstract：To obtain accurate internal microstructure information related to mine gas/air premixed gas deflagration flow fields, the evolutionary process of deflagration flow fields and the mechanism involved in inert medium flame retardant inhibition from the perspective of elementary reactions must be understood. A highspeed laser schlieren measurement system is constructed for the mesoscale shock pipeline. Due to the geometric space constraints in the laboratory, a design scheme of a Zshaped optical path for the schlieren measurement system is also proposed. The laser schlieren system replaces the traditional pressure flame measurement system, and the research focus of deflagration flow fields is shifted from macroscopic singlesource information to microscopic multistructure information. The results show that the chemical reaction of the flame front becomes stronger at 60, 100, 125, and 212 ms when accompanied by a shock wave. The flame breaks at approximately 75 ms, and the pressure decreases at this point. After a 325ms flame front sweeps over the measuring point, the pressure decreases rapidly. The results provide a basis for new research into methods other than highspeed photography for premixed gas deflagration and pressure flame velocity measurements.Keywords：laser schlieren;shock tube;optical path design;gas deflagration;flame retardant and explosion suppression- 44
- |
- 12
- |
- 4
Published：2020-08-13 -
Stability of machining system for fine turning largepitch thread
Abstract：In highfeed turning process, the dynamic characteristics of the machining system exhibit timevarying with realtime changes in the relative contact relationship between the rotating workpiece, the dynamic evolution of the tool wear and the cutting tool, and the quality change caused due to material removal. Combined with the dynamic model of largepitch thread, using the zeroorder frequency domain method and the improved fulldiscrete timedomain method, a cutting stability prediction method for turning largepitch thread was proposed and experimentally verified. Based on the timedomain method, considering the influence of process damping, the influence of different tool wear conditions on the cutting stability of the largepitch thread during finish turning process was investigated in this study, and consistency of the experimental measurements with the predicted results was verified. It is concluded that the ultimate cutting depth increases with the increase in tool wear; the machining parameters, such as the spindle speed is in the range 1025 r/min, cutting depth is 8 mm, and axial feed amount is 0.05 mm, which should be given priority in the process planning of trapezoidal screw with large pitch. The results obtained provide the theoretical basis for the optimization of largepitch thread turning process parameters. The enhancement and advancement of highspeed feed processing theory and highefficiency machining technology is of great importance for the development of large equipment key components represented by largepitch thread.Keywords：large-pitch thread;cutting stability;turning;Wear- 70
- |
- 7
- |
- 0
Published：2020-08-13
-
Gain-optimization trajectory planning method for hyper-redundant manipulator with joint constraints
Abstract：Because their inverse kinematics do not have analytical solutions, hyper-redundant manipulators cannot be directly solved by the geometric method. To realize real-time planning, this study proposes an artificial potential field trajectory planning method based on the Jacobian transposition matrix. Trajectory planning must satisfy not only the requirements of end-tracking accuracy but also the joint velocity and angular constraints. The joint velocity is mainly determined by the gain of the trajectory planni Keywords：artificial potential field;joint constraints;weighted joint velocities;Monte Carlo method;speed feedforward;Lyapunov stability theorem- 118
- |
- 13
- |
- 5
Published：2020-08-13 -
Ultra-precision grinding of monocrystalline silicon reflector
Abstract：An ultra-precision grinding process employing a rotational grinding technique was investigated to achieve high-efficiency, low-damage grinding of monocrystalline silicon reflectors. First, the characteristics of ultra-fine wheels, such as their surface topography and compositions, were analyzed. The grinding performance of wheels was studied based on the grinding of monocrystalline silicon. Then, the shape of the grinding surface was controlled based on the mathematical relationship between the posture angl Keywords：silicon reflector;workpiece rotational grinding;surface and subsurface damage;surface profile control;ultra-fine diamond wheel- 153
- |
- 31
- |
- 7
Published：2020-08-13 -
Grinding of typical functional brittle materials
Abstract：To evaluate the grinding performance of typical functional brittle materials, a back-face grinding model was established and subsequently the specific energy of the wafer material and the distribution of grinding force was calculated during the grinding process according to this model. First, a series of grinding experiments were conducted at different feed rates. The rate of increase of spindle power was then chosen to evaluate the grinding performance; the recorded data of grinding power varied significan Keywords：brittle materials;specific energy;distribution of grinding force;increasing rate of spindle power- 79
- |
- 14
- |
- 2
Published：2020-08-13 -
Static and dynamic load capacity of piezoelectric actuated ultrasonic levitation precision bearing
Abstract：An ultrasonic levitation bearing based on piezoelectric actuation is designed to study the static and dynamic capacities of an ultrasonic levitation bearing. In this paper, calculations and numerical simulations of the levitation force of a gas squeeze film bearing were done using the finite difference method and a MATLAB function to calculate discrete equations for numerical calculations. The Reynolds equation describing the pressure distribution of the gas film was established for the bearing's start-up a Keywords：ultrasonic levitation bearing;piezoceramics;squeezed film;bearing capacity- 139
- |
- 11
- |
- 2
Published：2020-08-13 -
Stability of machining system for fine turning large-pitch thread
Abstract：In high-feed turning process, the dynamic characteristics of the machining system exhibit time-varying with real-time changes in the relative contact relationship between the rotating workpiece, the dynamic evolution of the tool wear and the cutting tool, and the quality change caused due to material removal. Combined with the dynamic model of large-pitch thread, using the zero-order frequency domain method and the improved full-discrete time-domain method, a cutting stability prediction method for turning Keywords：large-pitch thread;cutting stability;turning;wear and tear- 80
- |
- 0
- |
- 0
Published：2020-08-13 -
Study of piezoelectric wind energy harvester with indirect excitation
Abstract：To improve the reliability and bandwidth of self-powered systems for environmental monitoring, a piezoelectric wind energy harvester with indirect excitation was presented. The piezoelectric beam in the shell was excited by the turbo-excited vibration generated by the coupling of the cylinder shell and wind. The proposed harvester had the advantages of high reliability and a wide dynamic adjustment range. This study introduced its structure and the principles of its operation while conducting theoretical an Keywords：indirect excited;piezoelectric power generation;wind energy harvester- 129
- |
- 15
- |
- 1
Published：2020-08-13 -
Design and experiment of high frequency jetting dispenser driven by double piezoelectric stacks
Abstract：To meet the requirements of high-frequency and micro-scale distribution of glue, a novel jetting dispenser with a corner-filleted flexure hinge driven by double piezoelectric stacks was developed. First, the output displacement and modal of the amplifier were calculated using finite element analysis software. The influencing factors of the structural parameters were discussed with regard to the requirement of high frequency operation. Based on the microelement method and analysis of the glue dynamics in the Keywords：electronic packaging;piezoelectric driving;high frequency dispensing;displacement amplifier- 140
- |
- 15
- |
- 3
Published：2020-08-13 -
Design and optimize of high tolerance support structure for large aperture space mirror
Abstract：In a traditional space mirror, the stress of processing and assembling cannot be eliminated and this causes the surface accuracy of the mirror to degrade. In this study, an optimization method for a high-stability support structure for a space mirror was proposed to solve this problem. A 1.5-m aperture high-tolerance and high-accuracy space mirror for engineering applications was fabricated. First, the initial configuration of the mirror subassembly was designed based on theory and experience. The mirror wa Keywords：large aperture;space mirror;high tolerance design;flexible support;assembly stress- 129
- |
- 36
- |
- 9
Published：2020-08-13 -
Optimization design of structural parameters of 2-DOF parallel stroke amplification mechanism
Abstract：The objective of this study was to develop a bionic quadruped robot that can realize fast walking and good mobility. Motion performance analysis and optimization of structural parameters for a 2-DOF parallel mechanism that can realize end-position travel amplification of the mechanism were conducted. Optimization results were then applied to the leg mechanism of a bionic quadruped robot, and a prototype was constructed. First, an inverse solution of the 2-DOF parallel travel amplification mechanism was dedu Keywords：parallel stroke amplification mechanism;kinematic flexibility;performance evaluation index;structure parameters;optimization design- 82
- |
- 12
- |
- 0
Published：2020-08-13
Micro/Nano Technology and Fine Mechanics
-
Feature fusion and weight adaptive updating based motion blur object tracking
Abstract：This study presents a motion blur object tracking method which combines the histogram of oriented gradient and hue saturation (HOGHS) with the Zernike moments features based on ECO_HC. This method was proposed to address object blur caused by the motion of the camera or the object itself. HOGHS was constructed by integrating fHOG with color features, and the properties of Zernike moments were introduced. The object was represented by combining HOGHS and Zernike moments. Furthermore, a novel quality evaluati Keywords：motion blur;object tracking;Zernike moments;ECO_HC- 141
- |
- 12
- |
- 4
Published：2020-08-13 -
High-frame frequency imaging system of large area CMOS image sensor
Abstract：For the demand of large area CMOS image sensor system with high frame frequency, designed the imaging system based on the GMAX0504 CMOS image sensor. It satisfied the demand of a large area sensor and high frame frequency imaging system; solved the problems of transmission speed and storage volume by the use of DDR3-SDRAM and NAND-FLASH; enhanced the image dynamic range(DR), SNR, MTF through real-time imaging processing; improved the image PRNU by pixel correction algorithm. The specifications of the experiments in the lab verified that the image SNR could be at 44 dB on average, almost the maximum SNR of the CMOS sensor; the image PRNU could be at 1.4% on average, up to the sensor PRNU specification. The new system and hardware structure could be used in a larger and faster area CMOS imaging system, and get better imaging specifications. It is a valid and solved scheme for further system design.Keywords：GMAX0504;High Dynamic Range(HDR);training;high-frame frequency;medianfilter;DDR3- 102
- |
- 21
- |
- 11
Published：2020-08-13 -
Adaptive feature fusion with the confidence region of a response map as a correlation filter tracker
Abstract：To correct the failure of some correlated filter trackers using a fixed weight feature fusion under illumination variation and deformation, the correlation filter tracker with an adaptive feature fusion and a confidence region of the response map is proposed for enhancing tracking robustness. The confidence region of the response map is the region where each response value is higher than the expectation of the response map. The fusing weights of a HOG response map and color histogram response map at every f Keywords：object tracking;feature fusion;adaptive;response map;confidence region- 166
- |
- 14
- |
- 2
Published：2020-08-13 -
Synchronous motion de-aliasing based on optical flow topological sparse weighting
Abstract：This work aims to overcome the limitations of Euclidean distance weighted sparse subspace clustering that does not consider the manifold structure of a rigid body. Here, a sparse subspace clustering method weighted using optical flow trajectory manifold topology was proposed. In the proposed algorithm, the manifold distance of each trajectory in the space-time similarity adjacency matrix was embedded into the weight matrix to solve the sparse coefficient. This ensured that the trajectory with a relatively closed manifold distance became the sparse self-expression dictionary, thereby reducing the clustering aliasing error of synchronous motion. The comparison of experiments between synchronous motion and synchronous swing reveals that the proposed algorithm can reduce aliasing error down to 1%. Finally, the motion segmentation results of Jacquard needle indicate that the algorithm can be potentially used for industrial applications.Keywords：variational optical flow;sparse subspace clustering;manifold distance;restricted isometry property;subspace aliasing;Dijkstra algorithm- 65
- |
- 10
- |
- 1
Published：2020-08-13 -
Fast helmet-wearing-condition detection based on improved YOLOv2
Abstract：Construction sites comprise changeable illumination, complicated backgrounds, and various types of construction personnel, which makes the detection of helmet wearing challenging. To address the problems of low accuracy and poor robustness of traditional detection methods, this paper proposed a method of helmet wearing detection based on deep learning. The proposed method was based on the YOLOv2 target detection, and its network structure was improved. First, utilizing the notion of densely connected networ Keywords：deep learning;target detection;helmets detection;densely connected networks;MobileNet- 227
- |
- 37
- |
- 20
Published：2020-08-13 -
TLD particle swarm optimization target tracking using a sample deletion mechanism
Abstract：This study improved the tracking robustness and real-time performance of a tracking-learning-detection (TLD) algorithm for a wide range of scenarios by considering two important aspects, namely, the tracking and learning modules. The study proposed a TLD particle swarm optimization (PSO) target-tracking algorithm using a sample deletion mechanism. First, the original tracking module of a TLD algorithm was replaced by a color-feature-based PSO target-tracking algorithm, which enhanced the tracking performanc Keywords：target tracking;TLD algorithm;learning module;sample deletion mechanism- 112
- |
- 10
- |
- 2
Published：2020-08-13 -
Automatic point cloud feature-line extraction algorithm based on curvature-mutation analysis
Abstract：Point cloud feature-line extraction is the basis of point cloud model reconstruction. Globally, the research on feature-line extraction from point clouds has been conducted in terms of edge detection, feature line tracking, and surface analysis. However, this seemingly simple operation is actually difficult to realize because of problems such as varied models, point cloud noise and imperfection, and feature complexity. Starting from the assertion that curvature mutated points imply the feature line of a sin Keywords：point cloud model;curvature mutation;feature line extraction;connection region;thinning algorithm- 128
- |
- 18
- |
- 12
Published：2020-08-13 -
Star image filling based on stellar image point trajectory
Abstract：Digital zenith camera is an astronomical instrument which is used to locate by taking star images. When taking a star image, there are star points missing in the star image due to external factors such as clouds, and the accuracy of positioning will be affected directly. In order to improve the practicability of the instrument and its adaptability to the environment, the stellar image point trajectory is derived and a star image filling method based on stellar image point trajectory is proposed. This method constructs a filling model between the missing star image and the adjacent two star images. The experimental data shows that the method can better fill the star image. The positioning error calculated by the filled star image is less than 0.001″. The positioning accuracy remains unchanged.Keywords：image point trajectory;missing star image;filling model- 106
- |
- 7
- |
- 1
Published：2020-08-13
Information Sciences
Loading...
0