Chinese Version Light学术出版中心
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Issue 2 ， 2010
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The variation of transverse chromatic aberration with the displacement of artificial stop and eccentricity based on the individual eye model
Abstract：The angle between visual axis and optical axis is calculated from the cornea data for eight eyes. According to the measurements of the corneal surfaces, the optical axis lengths, the wavefront aberrations and the angle obtained from calculation, the individual eye models involving the angle between visual axis and optical axis are constructed with ZEMAX software. The constructed eye models are then used to investigate the variations of transverse chromatic aberration (TCA) at fovea with the displacement of artificial pinhole from the visual axis. The result shows that TCA increases with the displacement linearly at an average ratio of 5.7 arcmin/mm, with some differences among the eight eyes over the range from 5.46 arcmin/mm to 5.95 arcmin/mm. Then, we investigate the variation of TCA with eccentricity over the spectrum from 420 nm to 700 nm. Across the field of view of 20°both at nasal and temporal, TCA increases with the eccentricity at an average ratio of 0.36 arcmin/deg for the eight eyes over the range from 0.32 arcmin/deg to 0.44 arcmin/deg. And the variation of TCA is slower at the end of long wavelength than that at the end of short wavelength.Keywords：Vision science;transverse chromatic aberration;individual eye model- 49
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Published：2020-08-12 -
Stray light analysis of three-mirror off-axis space optical telescope
Abstract：Stray light analysis results to a three-mirror off-axis space telescope was present in this article with the measurement of PST (Point Source Transmittance ). The entity model of the system was built to determine the first and second order scattering paths. The result was calculated by the improved Monte Carlo raytrace method between 20° off-axis angle. It was demonstrated that the stray lights mainly composed with the first order scattering, and was coincident closely with the structure of the optical system. The PST equaled to 3.56 and 4.02 at 0.1° off-axis angle, 6.63×10-5 and 4.48×10－5 at 20° off-axis angle. Comparing with the two-mirror off-axis telescope, the stray light of three-mirror system was graveness at the big off-axis angle, and could be reduced by changing the mirror’s scatting rate. The result indicated that it could meet the requirement.Keywords：Three-mirror off-axis telescope;stray light;Scattering path;PST- 62
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Published：2020-08-12 -
Alternate coded pattern for structured light system
Abstract：In structured light system, coded pattern is the key of corresponding problem. Performances of coded pattern directly affect measuring accuracy and resolution. In the paper, an analysis of the maximum stripe deformation (due to depth changes on surface) and measuring resolution limits are discussed, the principle of spatial periodicity used for coding is proposed. Performances of measurement greatly improve with use of spatial periodicity in coding. When spatial periodicity is used for coding, the resolution is greatly improved, or the number of pattern is greatly reduced for real-time structured light systems. According to those analyses, a novel coded pattern based on spatial periodicity for real-time structured light system is presented, which is alternate time-space coded pattern. These coded patterns allow range scanning of moving objects with easy implementation of decoding and high measurement resolution. Experiments demonstrated the validity of spatial periodicity used in coded pattern design.Keywords：Structured light system;Coded pattern design;Spatial periodicities;Alternate time-space coded pattern- 37
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Published：2020-08-12 -
Software design and implementation for Solar Backscatter Ultraviolet Spectrometer in FY-3A
Abstract：Satellite borne Solar Backscatter Ultraviolet Spectrometer (SBUS) which is independently developed for the first time in China has been put into use in-orbit. A significance change on research and detection of atmospheric ozone in china is brought by this. On the basis of the description for the working mode of SBUS, the analysis of the run task in-orbit is made and an introduction about the important points of software is explained in detail. The data of remote sensing measured in-orbit with solar/ atmospheric working mode are given. The results show that SBUS are working normally in-orbit, and measurement modes are implementing correctly, and the control parameters are valid. All functions of the embedded software are achievement and meet the requirements of application.- 58
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Published：2020-08-12 -
Further improvement of Iterative Error-Correction Method in laser direct writing
Abstract：Abstract: In order to further correct the optical proximity effect in laser direct writing, the Iterative Error-Correction Method proposed by Rajesh Menon is improved from two aspects. On the one hand, one virtual acoustooptic modulator with high resolution is used to correct the direct writing pattern, and then the exposure data obtained is converted and rounded to that corresponding to the low resolution acoustooptic modulator to avoid the degradation during correction. On the other hand, the exposure dose of writing spots nearest to each error area barycenter is modulated by performing serial global optimization with the minimum whole pattern error as a yardstick, which avoids failure to correct the optical proximity effect when the number of positive errors is equal to that of negative errors. Numerical simulation results indicate that, by the improved Iterative Error-Correction Method, the optical proximity effect of pattern with low resolution acoustooptic modulator can be preferably corrected, and that with high resolution acoustooptic modulator can be further corrected. Subsequently, the resolution of laser direct writing is enhanced.Keywords：laser direct writing;Optical proximity effect;Iterative Error-Correction Method- 46
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Published：2020-08-12 -
Ultra miniature absolute optical encoder based on eight-matrix coding
Abstract：In order to realize miniaturization of absolute optical encoder with the character of greater accuracy and more reliability, a new coding mode and structure of reading head are investigated. The eight-matrix coding used in absolute optical encoder, is different from custom four-matrix coding. Eight-matrix coding which reduce dimension of encoder greatly is a bran-new coding technique. It can realize the function of 10-bit binary coding through only two grating tracks. With the optimizing coding, we reduce the position errors which are brought by signals getting from two grating tracks. The grating tracks are more the position error is bigger. Single reading-head is also good for reducing dimension of encoder, so the number of LED is smaller. Moiré fringe obtained by phase compensation is another new technique in this paper. Experimental results indicate that eight-matrix encoder has smaller size (Φ25mm×16mm), lighter weight while higher resolution (resolution of 16-bit)and higher accuracy(30″). Also it can normally work in very hard condition for long time with more reliability. It can be widely applied to the field of modern military and aerospace.Keywords：optical encoder;absolute encoder;ultra miniature;eight-matrix;phase compensation- 56
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Published：2020-08-12 -
Band Selection for Space-based Infrared Target Detection Using Background Clutter Model
Abstract：The working band and its selection method of the U.S defense support program (DSP) are explored. A new method used to choose the optimal detection bands based on the background clutter model is proposed. The simplified parametric expression for scene radiation is deduced, and then the spatial clutter model is built. The synthetic signal-to-noise (SSNR) is given in analytic form. Finally, the optimal bands are chosen by searching all the scene clutter level space, target radiation characteristics space and the spectrum space, which provide the best system performance to detect some certain class of targets with the similar radiation characteristics under different clutter levels. The validity of the method is illustrated by examples. Calculation and analysis results indicate that the optimal detection bands are dependent on the scene clutter level and the target radiation characteristics. With two target radiation profiles, the optimal bands for DSP are 2.73~2.85μm and 4.2~4.43μm.Keywords：Clutter model;Space-based target detection;Band selection;Detection performance- 56
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Published：2020-08-12 -
A Mothed of Spectrum Data Real-time Acquisition with Wavelet Firm Shrinkage Filtering
Abstract：In order to improve the performance of Biochemical Analyzer, A Mothed of Spectrum Data Real-time Acquisition with Wavelet Filtering was presented in the paper. Average spectrum was calculated based on the two spectra which were collected. And the noise variance was calculated as the next threshold instead of noise variance estimation. Threshold will be adjusted on line deal with wavelet filtering. And give the evaluation criteria, in favor of the computer automatically. The experiment proved that superior to the traditional 10 times averaging method, the accuracy at high acquisition improve on the basic acquisition speed.In the main fiber-optic spectrometer for micro-biochemical analyzer Samples Detect application process showed that: improve the detection accuracy and reduce the detection time, increase efficiency by 4-5times.Keywords：Wavelet Filtering;CCD;spectral analysis;noise variance estimation- 41
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Published：2020-08-12 -
Research on fabrication of 3D metal microstructure based on UV-LIGA and micro-EDM technology
Abstract：A process to fabricate 3D metal microstructure based on UV-LIGA and micro-EDM technology was researched. 2D metal microstructure was fabricated by UV-LIGA technology firstly, and then it was machined using micro-EDM to get 3D metal microstructure. The method takes advantages of high machining accuracy and fabricating 3D metal microstructure with free-form surfaces. 3D nickel mold with trapezium table and taper flute microstructures in part was fabricated. The influence of micro-EDM discharge parameter on surface roughness was analyzed, and the surface roughness was dropped through reducing the discharge voltage and catacitance.Keywords：3D metal microstructure;UV-LIGA;micro-EDM;surface roughness- 38
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Published：2020-08-12 -
The Optimize Design of Supersonic Seeker’s Dome
Abstract：The figure of the dome have influents not only on the optical system, but also on the missile’s drag which can influent the field of fire. The dome’s figure is composed by inside figure and outside figure. In this paper, the CFD simulation is used to get the relation function between ellipticity and drag of the dome. To get the relation function of optical performance and ellipticity, we use OPD function as a tool to evaluate it. After deciding the weights of the aerodynamic and optical performance, here gets the final dome’s outside figure which is a elliptic with ellipticity equals to 2. As this is a foundation, and the minimum deviation of the light through dome as the optimizing goal, by using ray tracing method, the optimizing function is built up. After calculation, the inside figure of the dome is conic with R=33.31 c=-0.78.Keywords：dome;optimize design;CFD;ray tracking- 38
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Published：2020-08-12 -
Extraction of the central positions of light stripe in sub-pixel in 3D surface measurement based on light-sectioning method
Abstract：Central positions of light stripe are important for 3D surface measurement based on light-sectioning method. This paper presents a method to extract the central positions of light stripe in sub-pixel. The gray level of image is considered as a 2D function of the coordinates. The directional derivative and the gradient of the image of light stripe are calculated, and the pixel gradient represents the direction of the change in gray level, which is assumed as the normal direction of the light stripe curvilinear. Pixels at the positions of light stripe can be extracted by setting a threshold for both absolute value of the gradient and the gray level. The sub-pixel central positions of the light stripe are equal to the mean value of the gray-level-weighed positions of the pixels in the stripe’s adjacent region along the gradient direction. With this method, the normal direction of the stripe can be simplified to be the gray level gradient, avoiding thus complicated steps to calculate a Hessian matrix to get normal directions, and ensuring enough accuracy with less computation.Keywords：image processing;gradient of gray-level;central positions in sub-pixel- 42
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Published：2020-08-12 -
Experimental study on cutting performance of Al/SiCp composite with nano cemented carbide tool
Abstract：The SiC particle has higher hardness in the Al/SiCp composite, and the tool wear is fast when Al/SiCp composite is machined. Nano-cemented carbide is a novel material, which is superior to common cemented carbide on physical and mechanical properties, such as high hardness, toughness, flexural strength and higher wear resisting property. In this paper the nano cemented carbide tool WC-7Co was prepared, and the cutting experiment was done. And wear mechanism of nano cemented carbide tool and chip removal mechanism were studied. Results shaw, the wear mechanism of nano cemented carbide tool is abrasion wear due to the micro-cutting of SiC particles, and micro-chipping and micro-breakage of cutting edge under the high frequent interrupted impact of the SiC particles. The essence of cutting Al/SiCp is interrupted cutting. The Al/SiCp chip removal mechanism is breakout of the chip. Flank wear value of nano cemented carbide tool is about 30-50% less than common cemented carbide.Keywords：nano cemented carbide;Al/SiCp matrix composite;wear mechanism;interrupted cutting- 57
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Published：2020-08-12 -
A Generalized Predictive - Multimode PID Control Method for Giant Magnetostrictive Actuator
Abstract：Abstract: In order to overcome the significant impact of hysteresis on positioning precision when Giant Magnetostrictive Material Actuator（GMA） applied for fine positioning, under the condition of the hysteresis compensation, adaptive PID control method is studied and a multimode PID control method based on Generalized Predictive Control （GPC）principle is established. Firstly, the main idea of GPC principle is introduced and the relation between parameters of the PID controller and estimated-to-be parameters is derived. Then, for the quibble problem at the beginning stage,a multimode PID controller, which choose control method between regular PID and GPC-PID by PID parameters variability, is setup. At last, PID parameters are reached to fulfill displacement control for GMA. Experimental results indicate that although GPC-PID controller extends the consuming time of each execution step slightly by 7 ms, RMS of tracking error reduce 0.066μm, compared with Generalized Minimum Variability-Fuzzy PID (GMV-Fuzzy PID) controller. It can overcome the impact of inaccurate hysteresis and system modeling or disturbance, and is advantageous when both real-time and high precision requirements need to be met.Keywords：giant magnetostrictive actuator;precision positioning;generalized predictive control;multimodel control- 29
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Published：2020-08-12 -
Microneedles Array and Mask Compensation Based on X-ray Lithography
Abstract：A new microfabrication technology based on the PMMA（polymethylmethacrylate）microneedles has been presented，that was based on PCT technology with X-ray and lithography mask. By moving lithography mask, three-dimensional PMMA microstructures can be made. The fabricated shape had a direct dependence on the absorber on X-ray mask pattern. From the experiment, the final microstructure was not the same as the absorber pattern on X-ray mask. If there is no compensation for mask design, the deformed shapes of sloped side-wall on the exposed structures were observed, this would affect the performance of microneedles. The reason of the deformed shapes of sloped side-wall mainly analyzed in this paper was the nonlinear relationship between developing time and exposure energy. Base on the compensation of the mask pattern, the strength of microneedle with the channels was improved by changing the mask pattern from a hollow double right-triangular pattern to a hollow double semi- elliptic pattern.- 44
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Published：2020-08-12 -
Analysis of electrical parameters effect on cylindricity in electrical discharge machining small hole
Abstract：The statistical study shows that there are some relations between the electrical parameters and the machining quality in electrical discharge machining (EDM). In order to control the cylindricity error of small hole machined by EDM, it is very necessary to study the relations between the electrical parameters and the cylindricity of small hole by technology experiments. In the course of studying, a measurement of multiple sections by cartesian coordinate is proposed, and then the cylindricity quantitative evaluation of hole is achieved. Based on the method above, an orthogonal experiment is used, and the effect of some main electrical parameters (voltage, current, pulse width, inter pulse and tool-lifting) on cylindricity of small hole is studied. The results indicate that pulse width affects cylindricity most distinctly, the voltage is secondary, and the effect of rest parameters is weak. The discharge parameters combination is achieved to purchase the least cylindricity error.Keywords：EDM;small hole;discharge parameters;cylindricity evaluation;orthogonal experiment- 42
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Published：2020-08-12 -
Half-cover Offset FDK Algorithm of Helical Cone-beam CT
Abstract：Objective: The cone-beam helical computed tomography (CT) can scan the long object, but conventional x-ray CT imaging is based on the assumption that the entire cross-section of an object is illuminated with x-rays at each view angle. When inspecting large object, the conventional scanning mode is limited due to the width of planar detector. As an alternative, this paper developed field of view (FOV) half-cover scan such that slightly more than one half of required projection data is acquired. Method: When scanning, the gantry is translated horizontally, which direction is vertical to center ray. Then the conventional helical scan is executed. During reconstruction, the extended FDK (Feldkamp-Davis-Kress) algorithm is proposed with no rebinnging needed, and it is computationally as efficient as conventional helical cone-beam FDK algorithm. Result: Experimental results indicate that the FOV half-cover scan can extend the field of view up to 1.86 times, and the image quality, which is reconstructed by improved algorithm with small planar detector, is almost similar to the conventional algorithm with large planar detector. The reconstruction time is reduced 376.66 seconds due to the decrease of projections. Conclusion: The half-cover scan of helical cone-beam CT can extend the diameter of the field of view, and extended FDK algorithm is efficient.Keywords：X-ray imaging;Helical cone-beam CT;Half-cover scan;FDK algorithm- 25
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Published：2020-08-12 -
Three Dimensional Edge Detection Based on Wavelet Locating and Facet Model
Abstract：High accuracy and high speed are both required highly in actual industrial Computed Tomography (CT) three dimensional (3D) applications. Using facet model, we can obtain the precise image edge to meet the needs of high accuracy. But it will consume too much time when be used to detect 3D image edge, so it is difficult to be applied in 3-D edge detection of actual Industrial CT image. Against this problem, we present a method of 3D edge detection based on wavelet translate and facet model. When wavelet translate was be used to detect edge, the speed is high, but the result has relationship with the threshold. If threshold is small, the edge is a little thick that it is hard to locate exactly. If threshold is big, the edge is not continuous that we can’t get the complete contour. However, we just make use of this characteristic to increase the speed of facet model. Firstly, 3D wavelet transform is been used to 3D data of Industrial CT, the initial candidates of edge could be obtained by setting smaller threshold. Through this step the edge was been located roughly. Secondly, 3D facet model is been used to decide if the candidate is the true edge. Then the 3D image edge of high accuracy is located. The improved algorithm can accelerate the original facet model greatly by the preprocessing of 3D wavelet transform which can reduce the number of edge pixel candidates. Finally, experiments on actual Industrial CT 3D image data and simulated image data validate the efficiency and accuracy of the improved algorithm. The original and improved algorithm were both been realized by programming. Then two groups of experiment result was been obtained. The accuracy of the two algorithm was been compared by computing the area of the same object in the two groups of result. Comparison of the program runtime indicate the speed of improved algorithm is been increased. So the experiment results show that the improved method not only has the equivalent accuracy with direct facet model, but also increases the speed from 3.51 to 7.39 times. The image edge is simpler; the speed of algorithm is faster. In this way, 3D facet model which is high accurate can be used into actual Industrial CT 3D image processing. It is of actual significance to Industrial CT high accuracy and speed detection.Keywords：three dimensional;wavelet;facet;Industrial CT;edge detection- 28
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Published：2020-08-12 -
Noisy CT Linear Crack Detection Algorithm Based on Fast Beamlet Transform
Abstract：Objective: CT (Computed Tomography) is a useful tool to analyze object’s inner defect, its image more or less has noise. Crack is a common defect, with linear or piecewise linear characteristic. So, effectively detecting the linear crack in noisy image is the first important thing to analyze it. Method: A noisy CT linear crack detection algorithm based on fast Beamlet transform is presented in this paper. After analyzing the component and relation of Beamlet in mono-scale, a fast Beamlet transform is proposed. On the basis of it, a control variable about relativity is introduced. Then combining the tree-structure of Beamlet’s mutiscale and top to bottom inter-scale inhibition to optimize the object function, the linear crack is detected. Finally, considering the near pixels of detection result of linear crack, the edge of its domain is extracted. Result: In the numerical experiment, the images include original noisy CT image, adding Gaussian white noise of variance 0.1 to the original image, adding salt & pepper noise with density 0.1 to the original image. Compared with the method of Laplace, Canny or wavelet, the proposed method can detect the noisy CT linear crack effectively. Conclusion: Because Beamlet using lines to analyze the image data, the proposed method has robustness to noise. The detection result is convenient for next data analysis.Keywords：Industrial Computed Tomography;crack detection;fast Beamlet transform;Noise- 24
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Published：2020-08-12 -
Research on modified triangle identification algorithm
Abstract：Triangle star identification algorithm is widely used in attitude determination system, that adopts star sensor as navigation parts at present. But low characteristic dimensions lead to high percentage of redundancy and mistake. To improve accuracy of triangle identification algorithm, a modified algorithm which based on traditional one is proposed. Record the star pairs that meet interstellar angle threshold in star matrix, and count the guide star’s appearance simultaneously, according to the truth that each star must be attached to two sides of the triangle, eliminate the entire star pair which any particular star appears less than two times, then construct guide triangle from stars left in star matrix. Only take interstellar angle and relative magnitude of stars as pattern, decreases the capacity of the database, enhances the validity of results, for another thing, hashing search method used during star identification speeds up the identification process.- 42
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Published：2020-08-12 -
Research on Stereo Vision match Algorithm for Attitude Recognition of Manipulator
Abstract：The region-margin line segment stereo match algorithm is proposed based on the research on binocular stereo vision. The geometric characteristics of margin line segment and the color characteristics of the region are used to realize integrate matching. Using the information of color and color gradient direction, the integrate match is realized depend on all information of the geometric characteristics of the margin line segment and the region of the line segment. The experiment of attitude recognition of manipulator is done by the algorithm and the result shows that the algorithm could recognize the attitude of manipulator by higher accuracy in complicated background. The recognition accuracy reach to 0.017 and the expected aim is reached.Keywords：binocular stereo vision;manipulator;Match Algorithm;Attitude Recognition- 36
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Published：2020-08-12 -
An automatic image mosaic algorithm based on multi-domain features
Abstract：Abstract: In order to improve visual field of photos, an improved and automatic image mosaic algorithm is presented based frequency and time domain features. Phase correlation is used to sort the unordered image sequence and estimate the overlapping area, in which improved Harris operator is used to extract corners. Then, the initial feature point pairs are obtained with bidirectional greatest correlative coefficient, and the false feature point pairs are rejected by RANSAC. Finally, image mean combined linear weight function is used to implemented image mosaic. Experiment results show that this algorithm exceeds existing ones at stability and matching speed about 40％.It can efficiently solve the difficulty in confirming corresponding points and gain satisfying visual effect in image mosaics with notable illumination difference.Keywords：image mosaic;auto-sorting;corners detection;image fusion- 32
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Published：2020-08-12 -
Study on dynamic programming algorithm for space small targets detection
Abstract：In order to detect space small targets from sequence image, a improved dynamic programming algorithm is presented. First, the development and current situation of dynamic programming algorithm used in small targets detection was introduced. Second, Focus on the case of defocus which is common in project for obtaining the sub-pixel center of target, the recursive equation of score function was improved and multi-points accumulation with direction weight algorithm was presented, and the original multispeed plane calculation was also simplified. Finally, the key processes which were encountered in algorithm realization, but skipped over by previous literatures were discussed, include states initialization, constant false alarm rate threshold and track data structure. Analysis indicates that the computational complexity reduced about 50% under the condition of the certain parameters. Experimental results indicate that targets were detected in 5 frames with the multi-points algorithm, in contrast, a number of fake tracks were found until to 10th frame when use the original algorithm. The score SNR of 20 tracks with maximum score in 5th frame of multi-points algorithm is 0.87 higher than that of origin. The multi-points accumulation with direction weight algorithm is able to reduce the false alarm caused by speckle noise efficiently and raise the detection ability of dynamic programming.Keywords：dynamic programming;Small targets detection;Multi-points accumulation;Space images- 44
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Published：2020-08-12 -
Method of Architecture-based Software Reliability Estimation
Abstract：Architecture-based models are the prevalent approaches for the software reliability estimation. The failure behavior and the relationship between software modules are essential for the approaches. This paper presents an overview of architecture-based models and the assessment methods during the reliability estimation. Firstly, architecture-based models are classified as composite and hierarchical according to the solution method. Then, depending on the approach for application we advance the principle of analyzing software architecture and the modules’ interaction, assessing the module’s reliability, estimating the transferring probabilities. The approach will be practice in a real system’s reliability estimation.Keywords：software reliability;architecture-based model;software reliability estimation- 25
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Published：2020-08-12 -
A New Online 3D Measurement Method of Cement Clinker in Grate Cooler
Abstract：A mesh-candidate-based online 3D measurement method is proposed for reconstruction of the cement clinker in the grate cooler. The binocular stereo system is consist of two cameras with intersection of the optical axes. The wavelet multi-resolution algorithm is applied for improving the efficiency of measuring system. The few candidates were rematched using larger or smaller window according to histogram if the confidence coefficient value was low, and it reduced the measurement error caused by ambiguity. The measurement system reconstructed the surface of the cement clinker in grate cooler with high accuracy and efficiency.Keywords：machine vision;3D measurement;Depth Candidates;Cement Clinker- 34
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Published：2020-08-12 -
Study on automatic gain control algorithm of SBUV-ICCD
Abstract：In order to make SBUV-ICCD (Solar Blind Ultraviolet Enhanced CCD) detect variable radiation luminance's target, and avoid damage the device when it expose for high intensity radiation, a AGC (automatic gain control) algorithm has been proposed for SBUV-ICCD. The sum of N consecutive frames image's histogram has been treated as analysis object, divide it to four background section, target's section, brightness section and saturated section. The AGC algorithm has been accomplished using the proportion factor between brightness section and target's section as controlling parameters, also the coefficient between saturated section and brightness section. At last experiments has designed for test the performance of algorithm. Experimental results indicate that when the target's luminance boost up unexpected or fade rapidly, this algorithm can adjust the gain of ICCD quickly and effectively, make the image has satisfied resolution.Keywords：SBUV;ICCD;Automatic Gain Control- 60
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Published：2020-08-12 -
Work-piece Localization Method in Sub-aperture Stitching Test Based on Stereovision
Abstract：In order to realize sub-aperture stitching measurement of large-aperture optics, a work-piece localization method based on stereovision is introduced. A measurement system is established and its mathematical model, measuring principle and the obtain of the transformation matrix and etc is investigated. First, the measuring principle of the sub-aperture stitching test is introduced, and its requirement to the work-piece localization is analyzed. Then the stereovision measurement system is introduced, its measuring model is established. After that, the marked points’ 3D coordinates which are rigid connected with the optics under test are obtained and the transformation matrix can be solved out by quaternion method. Then, the full-aperture phase map can be synthesized by mathematically minimizing the mismatch among the overlapping areas of all sub-apertures. Finally, a 150mm flat and a 100mm convex sphere are tested using this method. Experimental results indicate that the precision of the system’s translation and rotation measurement are better than 0.1mm and 0.01degree, respectively. This can provide an effective initial value for the stitching algorithm and its measurement error does not cumulative along with the motion in its view field. It can satisfy the system’s precision requirements and it is non-contact, simple, and rapid speed, as well as strong anti-jamming and stabilization.Keywords：Stereovision;Large-aperture;Optics;Sub-aperture Stitching;Workpiece localization- 47
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Published：2020-08-12
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