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Issue 7 ， 2016
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Orbit determination of space objects with single satellite optical observations and virtual range
Abstract：Observability of optical monitoring data based on single space-based satellite is poor when the orbit is improved, iteration cannot be converged and even normal equation would be ill-conditioned, which would cause failure of cataloging and orbit determination of a large number of space targets. Features and difficulties of application of single-satellite optical monitoring to determine the orbit of space target were analyzed. Then the rank deficiency of orbit determination based on space-based monitoring an Keywords：optical observation;space object;space-based satellite;orbit determination;virtual range;successful rate- 93
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Published：2020-08-13 -
Distribution and suppression of higher-order harmonics of metrology beamline in 5~140 nm
Abstract：To correct and improve calibration and measurement precision of optical element performance at 5-140 nm waveband covered by metrology beamline, a scheme for higher-order harmonic suppression was designed based on spectral radiation standard of State Synchrotron Radiation Laboratory and distribution of higher-order harmonic of the metrology beamline. The distribution of the higher-order harmonic of metrology beamline at 5-140 waveband was studied by use of 3500, 8401/mm gold-film self-support transmission gr Keywords：synchrotron radiation;spectral metrology;higher-order harmonics;suppression- 81
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Published：2020-08-13 -
Surface modification of 2 m RB-SiC substrate by magnetron sputtering
Abstract：In order to eliminate the surface microdefect after the direct polishing of RB-SiC substrate, reduce the surface roughness and increase the surface quality, Si was selected as the modified material based on the features of large aperture SiC, where a 2 m-level RB-SiC substrate was modificated by using the magnetron sputtering technology. The silicon film was deposited by a developed Φ3.2 m magnetron sputtering coating machine, and the SiC substrate was polished and modificated based on the computer control Keywords：optical fabrication;magnetron sputtering;surface modification;RB-SiC;large aperture- 100
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Published：2020-08-13 -
Influence of sampling point distribution in freeform surfaces fitting with radial based function model
Abstract：In view of the importance of surface shape fitting precision of free-form surface model in researches such as free-form surface representation and selection of initiating structure of surface shape, the influence of different sampling point distribution patterns on surface shape fitting precision of the Gaussian Radial Basis Function Based on Slope(Gaussian RBF-BS) model was investigated. An off-axis quadric surface and an bumpy paraboloid were fitted with different sampling point distributions which were u Keywords：optical design;freeform surface;fitting precision;distribution of sampling points- 72
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Published：2020-08-13 -
Analysis of influence factors of resolution in high-resolution 4
f imaging systemAbstract：The factors and its mechanism which influence 4f imaging systemic resolution in practice were studied to guide the design and adjustment of the system. Firstly, the influence of the aberration caused by adjustment error on the system optical transfer function (MTF) in theory, whereby the mathematic model for describing the relationship of them was established. Based on the model, the adjustment error of 4f optical imaging system of 1 μm resolution was derived, and the influence of lens eccentricity, incline Keywords：information optics;4f transmission system;alignment;mathematical model;curve analysis;high resolution- 133
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Published：2020-08-13 -
Analysis of influence factors of resolution in high-resolution 4f imaging system
Abstract：The factors and its mechanism which influence 4f imaging systemic resolution in practice were studied to guide the design and adjustment of the system. Firstly, the influence of the aberration caused by adjustment error on the system optical transfer function (MTF) in theory, whereby the mathematic model for describing the relationship of them was established. Based on the model, the adjustment error of 4f optical imaging system of 1 μm resolution was derived, and the influence of lens eccentricity, incline and displacement on the MTF was simulated, thus the variations of the resolution with the errors were achieved. The result indicates that within the incline of 15", the eccentricity error is 0.02 mm and the displacement is within 0.01 mm. The adjustment error results in the decline of the resolution. Although the resolution increases while the incline within a minimum scope, the total trend will not change. The relationship figure of adjustment error and resolution can provide the reference for the error estimation of high-resolution 4f imaging system.Keywords：information optics;4f transmission system;alignment;mathematical model;curve analysis;high resolution- 49
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Published：2020-08-13 -
Extraction of laser stripe centers based on equal matching points for binocular vision measurement
Abstract：In order to extract laser stripe centers accurately and quickly and provide more suitable extraction results for binocular vision measurement of feature dimension, a laser stripe center extraction method with equivalent matching point was proposed. The gray centroid method was employed to extract central points of laser stripe, to calculate gray-gradient directions and to determine boundaries of laser stripe. Then coarse extraction results of laser stripe in the left and right images were used to determine Keywords：binocular vision measurement;extraction of laser stripe centers;equivalent matching points;subpixel- 134
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Published：2020-08-13 -
Calibration of area-array camera parameters based on improved exact measuring angle method
Abstract：An improved exact measuring angle algorithm is proposed for parameter calibration of area array cameras. Based on a given estimated principal point of camera, the algorithm calculated deviation between the estimated and actual principal points and focal distance of the camera by using the corresponding relationship between intersection angle of two beams of parallel lights and image point of projection on the camera. The influence of image feature extraction error on intersection angle measurement accuracy Keywords：angle measurement;area-array camera;intrinsic parameters;calibration precision- 96
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Published：2020-08-13
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Eye-safe LIDAR for short-range stand-off detection of bio-aerosols
Abstract：A portable bio-aerosol short-rang lidar-measuring system which meets laser irradiation eye-safe requirement was established to realize real-time warning and monitoring of aerosol of biological warfare agent in human activity areas. Taking a 405 nm semiconductor laser with high-frequency modulation as the excitation light source and a 200 mm-caliber Cassegrain telescope system as the signal light collection system, the portable bio-aerosol laser radar short-range lidar-measuring system based on pseudo-random Keywords：laser LIDAR;bio-aerosols;laser radiation;eye safe;pseudo-random modulation- 82
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Published：2020-08-13 -
Calibration of stray light based on point source transmittance measurement system
Abstract：To improve the stray light testing ability and calibration accuracy of the stray light equipment used in test of the Point Source Transmittance (PST), a calibration lens was proposed to calibrate the testing range and testing accuracy of the equipment in a large off-axial angle. By using a simple physical model, the calibration lens was designed in a laboratory. The physical parameters of the calibration lens were measured, then these parameters were taken into the TracePro to calculate the PSTs in differen Keywords：point source transmittance measurement;stray light measurement;standard lens;calibration;bidirectional reflectance distribution function- 85
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Published：2020-08-13 -
Sawing of optical glass assisted with ultrasonic vibration
Abstract：Based on ultrasonic vibration added in radial direction of saw-cutting ultra-thin abrasive cutting wheel, two kind of optical glasses with different physical properties were fabricated to explore the influence of radial ultrasonic vibration on saw-cutting process. The sawing force and sawing energy were deduced theoretically, and the cutting paths of single abrasive in conventional and ultrasonic assisted sawings were represented. Then K9 glass and quartz glass were machined by ultrasonic assisted sawing, d Keywords：optical glass;sawing;radial ultrasonic vibration- 63
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Published：2020-08-13 -
Material removal mechanism for fused glass by using soft particles
Abstract：On the basis of Arrhenius theory and molecular vibration theory, the elastic and hyper elastic contact among the soft polishing particles, fused glass and the polishing pad was analyzed, then the material removal mechanism of fused glass using soft particles in polishing process was explored. According to the theoretical research mentioned above, a lots of polishing experiments were carried out and a material removal rate model was established. Theoretical calculation and experimental results show that the Keywords：fused glass;chemico-mechanical polishing;soft polishing particle;material removal mechanism;model of material removal rate- 95
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Published：2020-08-13 -
Parameter sensitivity of thermal characteristics for micro-expansion type heat switch
Abstract：The effects of various uncertain factors in the conduction path of a micro-expansion type heat switch on its thermal characteristics including OFF thermal resistance, ON thermal resistance and ON/OFF ratio were researched using parameter sensitivity analysis method. By comparing with the property experiment, the validity of heat switch finite element thermal model was verified. Based on the model, the relevance between thermal conductivity of structural components, thermal contact conductance of mating surf Keywords：micro-expansion type heat switch;thermal characteristics;parameter sensitivity;uncertain factor- 69
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Published：2020-08-13 -
Optimization design of flexible and damping support structure of space camera
Abstract：According to the performance requirements of a high-resolution space camera for the bottom support structure, a flexible and damping support structure composited by a fillet feet frame and a straight beam was designed. Firstly, the bottom supporting structure of the space camera was designed based on the request of a satellite structure, and a optimized design model for the random response was established. The flexible link for the leg of two-feet frame structure was proposed with the size optimization tech Keywords：space camera;support structure;flexible and damping;random vibration;acceleration response;optimization design- 114
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Published：2020-08-13 -
Damage detection of nonmetallic pipe by using nonlinear ultrasonic guided wave with signal delay
Abstract：As the damages on nonmetallic pipes, especially early damages, are difficult to be detected by ultrasonic guided wave, this paper proposes a nonlinear ultrasonic guided wave with signal delay to detect and localize the defects on nonmetallic pipes. Based on the nonlinear ultrasonic wave theory, the damage states of nonmetallic pipes were analyzed and an incentive method with mixed signals from the same end of the signal delay was developed to generate signal delay according to different speeds of the mixing Keywords：nonmetallic pipe;damage location;ultrasonic guide wave detection with delay signal;nonlinear modulation- 87
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Published：2020-08-13 -
Adsorption of TiO2 nanoparticles on monocrystalline silicon surface
Abstract：To efficiently create the ultra-smooth surface of brittle crystals, an ultraviolet induced nanoparticle colloid jet machining system was established and the interaction mechanism between the nanoparticles and the surface of a workpiece in the process was investigated. Firstly, the characteristics of TiO2 nanoparticles and monocrystalline silicon surface used in the experiment were measured and investigated. Then, the plane-wave pseudopotential calculation method based on first-principles was used to study t Keywords：TiO2 nanoparticle;ultra smooth surface;monocrystalline silicon surface;chemical adsorption;ultraviolet induced nanoparticle colloid jet machining- 121
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Published：2020-08-13 -
Stiffness calculation and optimal design of elliptical flexure hinges
Abstract：An optimization design method for elliptical flexure hinges is researched. As the traditional calculation formula for the stiffness of elliptical flexure hinges is more complex, this paper deduces a approximate theoretical formula by nonlinear fitting method with power function. Based on the approximate theoretical formula, it analyzes the precision characteristics of the flexure hinges and their maximum stresses at working. Then, the global optimization solver GlobalSearch and local optimization solver Fmi Keywords：elliptical flexure hinge;rotation stiffness;stiffness calculation;nonlinear curve fitting;optimization design;finite element analysis- 103
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Published：2020-08-13 -
Control of active reflector system for radio telescope
Abstract：According to the control requirements of the active reflector surface in the 110 m radio telescope at QiTai(QTT) Xinjiang, a new displacement actuator and a new displacement control system were designed and manufactured and then their characteristics were tested by a dual-frequency laser interferometer in the micro-displacement laboratory. The displacement actuator was designed by a scheme of high precision worm and roller screw structures, and the displacement control system was based on a ARM micro-proces Keywords：radio telescope;active reflector;S curve acceleration control algorithm;displacement actuator;displacement control system- 91
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Published：2020-08-13 -
Compound support structure for large aperture mirror of space remote sensor
Abstract：For requirements of the mirror in a space remote sensor for support function, a compound support structure used in the mirror with a large aperture in the space field was designed. The compound support structure includes a peripheral support composed of an A frame and a tangential pull rod and a back support composed of three groups of whiffletree structures. The support principle and engineering realization of the compound support structure were researched. Then, the design idea of function allocation and Keywords：space remote sensor;large aperture mirror;compound support;simulation analysis;surface shape error test;mechanical test- 156
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Published：2020-08-13 -
Thermal error modeling for spindle system of precision CNC lathe
Abstract：The experiments and modeling of thermal error compensation for the spindle system of a Computer Numerical Control (CNC) lathe were researched. A thermal error compensation model for the Spindle system of CNC lathe at axial and radial directions was established to enhance its error compensation ability and to improve the machining precision. A test platform for the thermal error of the spindle system was built. The five point method was used to test the thermal error of the spindle system, and a thermocouple Keywords：precision Computer Numerical Control(CNC) lathe;spindle system;thermal error modeling;thermal error compensation;Re-sampling Step Particle Swam Optimization(RSPSO)- 106
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Published：2020-08-13
Micro/Nano Technology and Fine Mechanics
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Structure design and optimization of high heat load absorbers in SSRF front-end
Abstract：To handle the high heat load obtained by photon absorbers located in the front-end of Shanghai Synchrotron Radiation Facility (SSRF), the structure design and optimization of photon absorbers were researched. The dispersion strengthened copper called GlidCop AL-15 was used to manufacture the absorbers. Direct water cooling and grazing incidence structures were used to improve thermal controlled-release ability of the front-end photon absorbers. The Petukhov formula and Darcy-Weisbach formula were selected t Keywords：Shanghai Synchrotron Radiation Facility(SSRF);high heat load;photon absorber;front-end;structure design;thermal analysis- 42
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Published：2020-08-13 -
Multi-scale representation for skin models in geometrical product specifications
Abstract：As most of the Computer Aided Tolerancing tools can only deal with the CAD models with an ideal surface and can not reflect manufacturing errors in physics and geometry, this paper explores a multi-scale representation method for skin model shapes in the Geometrical Product Specification. A discrete data modeling method was proposed for the simulation of topographic errors of surfaces and section profiles of a product in macroscopic and microcosmic scales based on new-generation geometrical product specific Keywords：geometrical product specification;skin model;discrete geometry;wavelet analysis;multi-scale representation- 67
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Published：2020-08-13 -
Installation error control of dynamic measurement for small photoelectric encoder
Abstract：The installation errors leaded by deflections from two axes of a measured encoder and a reference encoder were researched in the process of dynamic measurement to improve the accuracy and reliability of photoelectric encoders. The effect of installation errors on measurement accuracy of the measuring accuracy of the measured encoder was analyzed and the installation error formula and a error control range formula were derived. To reflect the actual measuring accuracy of the encoder by encoder dynamic measur Keywords：photoelectric encoder;dynamic measurement;installation misalignment;error control- 90
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Published：2020-08-13 -
Random vibration and fatigue analysis of off-axis reflective optical system structures
Abstract：In order to research the performance of off-axis reflective optical system against the dynamic environment, the random vibration and fatigue analysis is presented. The finite element model of optical system structures is established and its modal analysis is performed by the finite element software MSC/Patran. The boundary conditions are used as the connecting hole of the base frame which in the actual assembly. The analysis results are obtained by constraint to the each node, and it shows that the change o Keywords：off-axis reflective;optical system structure;finite element analysis;random vibration;fatigue analysis- 102
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Published：2020-08-13 -
Broadband generation performance of two-degree-of-freedom cantilever beam piezoelectric generator
Abstract：A two-degree-of-freedom cantilever beam piezoelectric generator was explored to improve the generation performance of the cantilever beam piezoelectric generator under the variety of the ambient vibration energy sources. The theoretical model of the frequency characteristics of the two-degree-of-freedom cantilever beam piezoelectric generator was established and finite element analysis was performed for the proposed theoretical model. The theoretical results show that the theoretical analysis and finite ele Keywords：piezoelectric generator;two-degree-of-freedom cantilever beam;broadband;frequency characteristics- 95
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Published：2020-08-13
Micro/Nano Technology ang Fine Mechanics
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Fusion of infrared and visible images based on target segmentation and compressed sensing
Abstract：The image fusion of infrared and visible light is susceptible to noise and the target information is weakened easily. Therefore, a new fusion algorithm based on target area extraction and compressed sensing was proposed. Firstly, the infrared image was detected in a salient region at frequency-tuned domain to obtain a corresponding salient map. Under the guidance of the salient map, the infrared target area was extracted together with region growing method to effectively overcome the effects of noise and co Keywords：image fusion;infrared image;visible image;saliency map;non-subsampled shearlet transform;target segmentation;Compressed sensing;multi-resolution singular value decomposition- 120
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Published：2020-08-13 -
Application of improved complete ensemble empirical mode decomposition with adaptive noise in spectral signal denoising
Abstract：As the accuracy and stability of a blood glucose level model is affected by the noise in near infrared non-invasive blood glucose detection process, an improved complete ensemble empirical mode decomposition method with adaptive noise was proposed for denoising of near infrared spectroscopy signals. Meanwhile, a mode selection method based on Frechet distance combining with the feature of curve curvature was proposed for the selection of Intrinsic Mode Functions(IMFs). Firstly. the complete ensemble empiric Keywords：non-invasive blood glucose detection;near infrared spectroscopy;signal denoising;Complete Ensemble Empirical Mode Decomposition with Adaptive Noise(CEEMDAN);curvature;discrete Frechet distance- 107
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Published：2020-08-13 -
Fusion of infrared and visible images combined with NSDTCT and sparse representation
Abstract：A novel fusion method of infrared and visible images was proposed based on Non-subsampled Dual-tree Complex Contourlet Transform (NSDTCT) and sparse representation to overcome the shortcomings of traditional image fusion method based on wavelet transform. With the proposed method, morphological transform was used to deal with source images, and then the source images were decomposed by the NSDTCT to obtain the low frequency sub-band coefficients and high frequency sub-band coefficients. According to the dif Keywords：image fusion;infrared image;visible image;Non-subsampled Dual-tree Complex Contourlet Transform(NSDTCT);sparse representation;Adaptive Dual Channel Pulse Coupled Neural Network(APCNN);morphology transform- 89
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Published：2020-08-13 -
Rail image segmentation based on Otsu threshold method
Abstract：As rail images show uneven gray distribution, general image segmenting methods can not accurately segment rail images. To address this issue, this paper presents an improved Otsu method using weighted object variance (WOV) for rail image segmentation to separate the defect from its background. Firstly, the property of a rail image was analyzed and the problems of the Otsu method and other global threshold methods for segmenting rail images were summarized. Then, the Otsu method was improved. By taking the c Keywords：image segmentation;Otsu thresholding;surface defects;machine vision;rail- 284
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Published：2020-08-13 -
Moving target detection under moving base
Abstract：Traditional moving target detection under a moving base has a problem of larger background interference, and its detection accuracy is effected by the noise interference. This paper proposes a moving target detection method under the moving base by using orthogonal Fourier transform and kernel-grayscale chart to overcome the influence of a larger illumination change and background noise on moving target detection accuracy. Firstly, the evaluation function was introduced the selection of a feature matching b Keywords：moving target detection;moving base;orthogonal Fourier transform;kernel-gray chart- 99
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Published：2020-08-13 -
Improved video defogging based on fog theory
Abstract：To improve the usability of a foggy video, an improved video defogging method based on fog theory was proposed. By using dark channel prior knowledge, Retinex method and image fusion, the method applies the values of global atmospheric light and a medium transmission map estimated from the video backgrfound image to defogging of all the video frames. The effects of the defogging for the video image were evaluated by three methods in subjective qualitative evaluation, objective quantitative evaluation and op Keywords：video defogging;atmospheric scattering model;dark channel prior knowledge;retinex method;image fusion- 103
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Published：2020-08-13 -
Design of longitudinal control law for small fixed-wing UAV during auto landing
Abstract：For the auto landing precisely of an Unmanned Aerial Vehicle(UAV), the longitudinal control law for the auto landing of the UVA was designed based on Adaptive Internal Model Control (AIMC) principle. By taking a small wheeled UVA as a working platform, the longitudinal nonlinear model was decoupled and linearized. Then, the ground speed and sink rate were selected as control targets and longitudinal control law was designed based on the AIMC and applied to control system design. The filter parameter was adj Keywords：Unmanned Aerial Vehicle(UAV);auto landing;Adaptive Internal Model Control(AIMC);longitudinal control law;digital simulation;Hardware in Loop Simulation(HILS)- 89
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Published：2020-08-13 -
Multi-ship saliency detection via patch fusion by color clustering
Abstract：Because the boundary pixels are easy to be classified as a background in the multi ship target detecting processing, this paper proposes a multi-ship saliency detection method based on patch fusion by color clustering. Firstly, this method detects the color similarity of the pixels in the neighbourhood, and the adjacent pixels with the similar color are gathered as an image patches. Then, the image patches are expanded to make them include some pixels of other patches, so as to enhance the contrast value of Keywords：multi-target detection;saliency detection;ships;image patch;color clustering- 64
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Published：2020-08-13 -
Estimation of DOA and polarition parameters for single electromagnetic vector sensor based on FLOCC
Abstract：A Fractional Lower Order Cyclic Correlation (FLOCC)-based MUSIC method was proposed for estimation of the Direction of Arrival (DOA) and polarization parameters for a single electromagnetic vector sensor in mixed α and Gaussian noises and cycle stable interference signals. On the basis of the cyclic stability of signals, the FLOCC function was used to suppress the cyclic stationary disturbance signal and the mixed α and Gaussian noises. Then, MUSIC method was used to estimate the DOA and polarization parame Keywords：single electro magnetic vector sensor;Direction of Arrival(DOA);polarization parameter;parameter estimation;Fractional Lower Order Cyclic Correlation(FLOCC)- 108
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Published：2020-08-13
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