Scale Invariant Feature Transform (SIFT) has been proven to perform better on the distinctiveness and robustness than other features. But it cannot satisfy the needs of low contrast images matching and the matching results are sensitive to 3D viewpoint change of camera. In order to improve the performance of SIFT to low contrast images and images with large 3D viewpoint change, a new matching method based on improved SIFT is proposed. First, an adaptive contrast threshold is computed for each initial key point in low contrast image region, which uses pixels in its 9×9 local neighborhood, and then using it to eliminate initial key points in low contrast image region. Second, a new SIFT descriptor with 48 dimensions is computed for each key point. Third, a hierarchical matching method based on epipolar line and differences of key points’ dominate orientation is presented. The experimental results prove that the method can greatly enhance the performance of SIFT to low contrast image matching. Besides, when applying it to stereo images matching with the hierarchical matching method, the correct matches and matching efficiency are greatly enhanced.
{"title":"Improved SIFT descriptor applied to stereo image matching","authors":"Luan Zeng, You Zhai, W. Xiong","doi":"10.1117/12.2180667","DOIUrl":"https://doi.org/10.1117/12.2180667","url":null,"abstract":"Scale Invariant Feature Transform (SIFT) has been proven to perform better on the distinctiveness and robustness than other features. But it cannot satisfy the needs of low contrast images matching and the matching results are sensitive to 3D viewpoint change of camera. In order to improve the performance of SIFT to low contrast images and images with large 3D viewpoint change, a new matching method based on improved SIFT is proposed. First, an adaptive contrast threshold is computed for each initial key point in low contrast image region, which uses pixels in its 9×9 local neighborhood, and then using it to eliminate initial key points in low contrast image region. Second, a new SIFT descriptor with 48 dimensions is computed for each key point. Third, a hierarchical matching method based on epipolar line and differences of key points’ dominate orientation is presented. The experimental results prove that the method can greatly enhance the performance of SIFT to low contrast image matching. Besides, when applying it to stereo images matching with the hierarchical matching method, the correct matches and matching efficiency are greatly enhanced.","PeriodicalId":380636,"journal":{"name":"Precision Engineering Measurements and Instrumentation","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120976715","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper studied the effect of curvature on the charge sensitivity of a curved PVDF sensor. The sensor was fabricated by attaching a PVDF film along the X-axis on a group of cylindrical silicon rods to form an outline with several bumps. The open output voltage of a curved sensor was simulated by using ANSYS with a rod curvature of 333 m-1, 400 m-1 and 500 m-1. It was found that the sensitivity was the highest when the curvature was 500 m-1, and the lowest when the curvature was 333 m-1. Curved PVDF sensors were fabricated and tested with a PVDF patch of 30 mm long and 28 μm thick and a radius of silicon rod of 3 mm, 2.5 mm and 2 mm, respectively. A shaker and mass block were used to apply the same dynamic force to the curved sensors and an oscilloscope was used to observe the output charge. The experiment results are not ideal but do show the same tendency as the simulation. The charge sensitivity increased as the curvature of substrate increased.
{"title":"Research on the relationship between the curvature and the sensitivity of curved PVDF sensor","authors":"Lu Shi, Yue Zhang, Weijie Dong","doi":"10.1117/12.2180862","DOIUrl":"https://doi.org/10.1117/12.2180862","url":null,"abstract":"This paper studied the effect of curvature on the charge sensitivity of a curved PVDF sensor. The sensor was fabricated by attaching a PVDF film along the X-axis on a group of cylindrical silicon rods to form an outline with several bumps. The open output voltage of a curved sensor was simulated by using ANSYS with a rod curvature of 333 m-1, 400 m-1 and 500 m-1. It was found that the sensitivity was the highest when the curvature was 500 m-1, and the lowest when the curvature was 333 m-1. Curved PVDF sensors were fabricated and tested with a PVDF patch of 30 mm long and 28 μm thick and a radius of silicon rod of 3 mm, 2.5 mm and 2 mm, respectively. A shaker and mass block were used to apply the same dynamic force to the curved sensors and an oscilloscope was used to observe the output charge. The experiment results are not ideal but do show the same tendency as the simulation. The charge sensitivity increased as the curvature of substrate increased.","PeriodicalId":380636,"journal":{"name":"Precision Engineering Measurements and Instrumentation","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116685083","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A new method based on quadratic programming theory is proposed to determine the regularization parameter. A function whose variable is the derivative with respect to the regularization parameter is formulated. Based on the property that the value of the function is very dependent on the regularization parameter, the optimal parameters can be determined by using quadratic programming theory. A numerical example is utilized to select the parameters through the method. It is concluded that the new method can effectively overcome the ill-posed problems from an ill-conditioned system matrix, and that it can obtain an approximate solution with higher accuracy, fine stability and effective noise resistance.
{"title":"A new method for determining the Tikhonov regularization parameter of load identification","authors":"Wei Gao, Kaiping Yu","doi":"10.1117/12.2180739","DOIUrl":"https://doi.org/10.1117/12.2180739","url":null,"abstract":"A new method based on quadratic programming theory is proposed to determine the regularization parameter. A function whose variable is the derivative with respect to the regularization parameter is formulated. Based on the property that the value of the function is very dependent on the regularization parameter, the optimal parameters can be determined by using quadratic programming theory. A numerical example is utilized to select the parameters through the method. It is concluded that the new method can effectively overcome the ill-posed problems from an ill-conditioned system matrix, and that it can obtain an approximate solution with higher accuracy, fine stability and effective noise resistance.","PeriodicalId":380636,"journal":{"name":"Precision Engineering Measurements and Instrumentation","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122897068","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Qian Li, Xiaojun Liu, Zili Lei, Yi Zheng, Liangzhou Chen, Wenlong Lu
Piezoelectric ceramics with a flexible hinge guide was used for fine positioning at nanometer level, while a stepping motor was used for coarse positioning with a resolution at micrometer level, and their combination helped fulfillment of vertical scanning positioning with large range and nanometer resolution. A grating sensor was used for the real-time measurement of scanning displacement for close-loop positioning control. The properties of the flexible hinge guide was analyzed using ANSYS. Experimental results indicated the performance of the system was good. The system had a good application prospect in an optical profiler for surface measurement.
{"title":"A vertical scanning positioning system with large range and nanometer resolution for optical profiler","authors":"Qian Li, Xiaojun Liu, Zili Lei, Yi Zheng, Liangzhou Chen, Wenlong Lu","doi":"10.1117/12.2181351","DOIUrl":"https://doi.org/10.1117/12.2181351","url":null,"abstract":"Piezoelectric ceramics with a flexible hinge guide was used for fine positioning at nanometer level, while a stepping motor was used for coarse positioning with a resolution at micrometer level, and their combination helped fulfillment of vertical scanning positioning with large range and nanometer resolution. A grating sensor was used for the real-time measurement of scanning displacement for close-loop positioning control. The properties of the flexible hinge guide was analyzed using ANSYS. Experimental results indicated the performance of the system was good. The system had a good application prospect in an optical profiler for surface measurement.","PeriodicalId":380636,"journal":{"name":"Precision Engineering Measurements and Instrumentation","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123776868","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The dynamic testing of structures and components is an important area of research. Extensive researches on the methods of using sensors for vibration parameters have been studied for years. With the rapid development of industrial high-speed camera and computer hardware, the method of using stereo vision for dynamic testing has been the focus of the research since the advantages of non-contact, full-field, high resolution and high accuracy. But in the country there is not much research about the dynamic testing based on stereo vision, and yet few people publish articles about the three-dimensional (3D) reconstruction of feature points in the case of dynamic. It is essential to the following analysis whether it can obtain accurate movement of target objects. In this paper, an object with sinusoidal motion is detected by stereo vision and the accuracy with different feature detection algorithms is investigated. Three different marks including dot, square and circle are stuck on the object and the object is doing sinusoidal motion by vibration table. Then use feature detection algorithm speed-up robust feature (SURF) to detect point, detect square corners by Harris and position the center by Hough transform. After obtaining the pixel coordinate values of the feature point, the stereo calibration parameters are used to achieve three-dimensional reconstruction through triangulation principle. The trajectories of the specific direction according to the vibration frequency and the frequency camera acquisition are obtained. At last, the reconstruction accuracy of different feature detection algorithms is compared.
{"title":"3D reconstruction for sinusoidal motion based on different feature detection algorithms","authors":"Peng Zhang, Jin Zhang, Huaxia Deng, Liandong Yu","doi":"10.1117/12.2181388","DOIUrl":"https://doi.org/10.1117/12.2181388","url":null,"abstract":"The dynamic testing of structures and components is an important area of research. Extensive researches on the methods of using sensors for vibration parameters have been studied for years. With the rapid development of industrial high-speed camera and computer hardware, the method of using stereo vision for dynamic testing has been the focus of the research since the advantages of non-contact, full-field, high resolution and high accuracy. But in the country there is not much research about the dynamic testing based on stereo vision, and yet few people publish articles about the three-dimensional (3D) reconstruction of feature points in the case of dynamic. It is essential to the following analysis whether it can obtain accurate movement of target objects. In this paper, an object with sinusoidal motion is detected by stereo vision and the accuracy with different feature detection algorithms is investigated. Three different marks including dot, square and circle are stuck on the object and the object is doing sinusoidal motion by vibration table. Then use feature detection algorithm speed-up robust feature (SURF) to detect point, detect square corners by Harris and position the center by Hough transform. After obtaining the pixel coordinate values of the feature point, the stereo calibration parameters are used to achieve three-dimensional reconstruction through triangulation principle. The trajectories of the specific direction according to the vibration frequency and the frequency camera acquisition are obtained. At last, the reconstruction accuracy of different feature detection algorithms is compared.","PeriodicalId":380636,"journal":{"name":"Precision Engineering Measurements and Instrumentation","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126349132","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A ranging algorithm based on process measurement was proposed for low-altitude radio fuzes with wide range of action and low request of absolute ranging precision. For those particular applications, a conception of relative burst height was given to control the initiation point of a fuze instead of the absolute burst height. The received echo power was analyzed and its relationship with the relative burst height was derived. The basic principle and implementation of the ranging algorithm were discussed and the simulation results were given including anti-white Gaussian noise performance and anti-active jamming performance. The results proved the feasibility of the ranging algorithm based on process measurement. It could be used to help the further researches of low altitude radio fuzes.
{"title":"Ranging algorithm based on process measurement for low-altitude radio fuzes","authors":"Xiaolu Chen, Tao Xu, Biao Chen, Ronghua Tao","doi":"10.1117/12.2181245","DOIUrl":"https://doi.org/10.1117/12.2181245","url":null,"abstract":"A ranging algorithm based on process measurement was proposed for low-altitude radio fuzes with wide range of action and low request of absolute ranging precision. For those particular applications, a conception of relative burst height was given to control the initiation point of a fuze instead of the absolute burst height. The received echo power was analyzed and its relationship with the relative burst height was derived. The basic principle and implementation of the ranging algorithm were discussed and the simulation results were given including anti-white Gaussian noise performance and anti-active jamming performance. The results proved the feasibility of the ranging algorithm based on process measurement. It could be used to help the further researches of low altitude radio fuzes.","PeriodicalId":380636,"journal":{"name":"Precision Engineering Measurements and Instrumentation","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131260013","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The flow rate is calculated via ultrasonic flow meter (UFM), which is through measuring the difference of time transmitting flow between flow direction and reverse direction. This paper describes the uncertainty analysis for the method of time difference which is commonly used in ultrasonic flow measurement, and the analysis of error source of uncertainty components as well as the general method of elimination. Based on the technique of pseudo random sequence, this paper presents a precise time difference method based on digital correlation technology, and its principle, realization way and uncertainty evaluation are introduced. On the DSP and FPGA system platform, an ultrasonic flow meter scheme based on the digital correlation technology is suggested.
{"title":"Investigating of precision measurement on ultrasonic flow","authors":"F. Jiang, Q. Ji, D. Zhai, Yibo Dong, Chun Dong","doi":"10.1117/12.2181965","DOIUrl":"https://doi.org/10.1117/12.2181965","url":null,"abstract":"The flow rate is calculated via ultrasonic flow meter (UFM), which is through measuring the difference of time transmitting flow between flow direction and reverse direction. This paper describes the uncertainty analysis for the method of time difference which is commonly used in ultrasonic flow measurement, and the analysis of error source of uncertainty components as well as the general method of elimination. Based on the technique of pseudo random sequence, this paper presents a precise time difference method based on digital correlation technology, and its principle, realization way and uncertainty evaluation are introduced. On the DSP and FPGA system platform, an ultrasonic flow meter scheme based on the digital correlation technology is suggested.","PeriodicalId":380636,"journal":{"name":"Precision Engineering Measurements and Instrumentation","volume":"7 2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132927291","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jingzhi Huang, T. Sun, Wei Gu, Zhong Wen, Tenghui Guo
With the fast development of the advanced equipment manufacturing toward precision and ultra-precision trend, especially with the continuously improving of the aviation engine’s performance, the problem of high displacement resolution for the large-load two-dimension adjusting and positioning worktable used for the aeroengine assembling become evident. A method was proposed which is based on the invariable restoring force, and the adjusting and positioning physical model was established. The experiment results indicate that under the occasion of a load with 508 kilogram, the worktable has got a displacement resolution of 0.3μm after using the improved method compared to 1.4μm of the traditional method. The improved method could meet the requirements of aviation engine assembling worktable.
{"title":"Adjusting and positioning method with high displacement resolution for large-load worktable based on the invariable restoring force","authors":"Jingzhi Huang, T. Sun, Wei Gu, Zhong Wen, Tenghui Guo","doi":"10.1117/12.2181818","DOIUrl":"https://doi.org/10.1117/12.2181818","url":null,"abstract":"With the fast development of the advanced equipment manufacturing toward precision and ultra-precision trend, especially with the continuously improving of the aviation engine’s performance, the problem of high displacement resolution for the large-load two-dimension adjusting and positioning worktable used for the aeroengine assembling become evident. A method was proposed which is based on the invariable restoring force, and the adjusting and positioning physical model was established. The experiment results indicate that under the occasion of a load with 508 kilogram, the worktable has got a displacement resolution of 0.3μm after using the improved method compared to 1.4μm of the traditional method. The improved method could meet the requirements of aviation engine assembling worktable.","PeriodicalId":380636,"journal":{"name":"Precision Engineering Measurements and Instrumentation","volume":"9446 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130486721","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Energy harvesting systems are interesting for use in remote power supplies. Many such systems utilize the motion or deformation associated with vibration, converting the mechanical energy to electrical energy, and supplying power to other electronic devices. In terms of energy harvesting from mechanical vibrations, piezoelectric conversion has received much attention as it can directly convert applied strain energy into useable electric energy and easily be integrated into a microsystem. The removal of mechanical energy from a vibrating structure necessarily leads to a damping effect. This paper addresses the damping associated with a piezoelectric energy harvesting system which is called the adaptive synchronized switching harvesting (ASSH) technique. Furthermore, a self-powered circuit which implements the technique (ASSH) is proposed, which validates that the new technique can be truly self-powered. Experimental results show that the vibration amplitudes of the first two modes are reduced by about 9.27 dB and 0.96 dB in the case of the exciting signal of same amplitude ratio (3:3), respectively. Compared with other self-powered vibration damping technique, this technique not only shows its robustness, but also harvests the energy and supply power to other electronic circuits.
{"title":"Multimode vibration damping as a result of piezoelectric energy harvesting","authors":"Hui Shen, Fengsheng Zhang, J. Qiu, Yixiang Bian","doi":"10.1117/12.2181515","DOIUrl":"https://doi.org/10.1117/12.2181515","url":null,"abstract":"Energy harvesting systems are interesting for use in remote power supplies. Many such systems utilize the motion or deformation associated with vibration, converting the mechanical energy to electrical energy, and supplying power to other electronic devices. In terms of energy harvesting from mechanical vibrations, piezoelectric conversion has received much attention as it can directly convert applied strain energy into useable electric energy and easily be integrated into a microsystem. The removal of mechanical energy from a vibrating structure necessarily leads to a damping effect. This paper addresses the damping associated with a piezoelectric energy harvesting system which is called the adaptive synchronized switching harvesting (ASSH) technique. Furthermore, a self-powered circuit which implements the technique (ASSH) is proposed, which validates that the new technique can be truly self-powered. Experimental results show that the vibration amplitudes of the first two modes are reduced by about 9.27 dB and 0.96 dB in the case of the exciting signal of same amplitude ratio (3:3), respectively. Compared with other self-powered vibration damping technique, this technique not only shows its robustness, but also harvests the energy and supply power to other electronic circuits.","PeriodicalId":380636,"journal":{"name":"Precision Engineering Measurements and Instrumentation","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115238433","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yongying Yang, Limin Zhao, Shitong Wang, Pin Cao, Dong Liu, Lu Li, Lu Yan, Chen Li, Shibin Xie, Yang Li, Yangjie Chen
The high-resolution detecting system based on machine vision for defects on large aperture and super-smooth surface uses a novel ring telecentric lighting optical system detecting the defects on the sample all round and without blind spots. The scattering light induced by surface defects enters the adaptive and highly zoom microscopic scattering dark-field imaging system for defect detecting and then forms digital images. Sub-aperture microscopic scanning sampling and fast stitching on the surface is realized by using precise multi-axis shifting guided scanning system and a standard comparison board based upon binary optics is used to implement fast calibration of micron-dimension defects detected actually. The pattern recognition technology of digital image processing which can automatically output digitalized surface defects statements after scaling is established to comprehensively evaluate defects. This system which can reach micron-dimension defect resolution can achieve detections of large aperture components of 850 mm × 500 mm, solve the durable problem of subjective uncertainty brought in by human visual detection of defects and achieve quantitative detection of defects with machine vision.
基于机器视觉的大孔径超光滑表面缺陷高分辨率检测系统采用一种新颖的环形远心照明光学系统，对样品上的缺陷进行全方位无盲点检测。表面缺陷产生的散射光进入自适应高变焦显微散射暗场成像系统进行缺陷检测，形成数字图像。采用精密多轴移位引导扫描系统实现了表面亚孔径显微扫描采样和快速拼接，采用基于二元光学的标准比较板对实际检测到的微米级缺陷进行了快速标定。建立了数字图像处理的模式识别技术，该技术可在标度后自动输出数字化的表面缺陷陈述，对缺陷进行综合评价。该系统可以达到微米级的缺陷分辨率，可以实现850 mm × 500 mm的大孔径部件的检测，解决了人类视觉检测缺陷带来的持久的主观不确定性问题，实现了机器视觉对缺陷的定量检测。
{"title":"A high-resolution detecting system based on machine vision for defects on large aperture and super-smooth surface","authors":"Yongying Yang, Limin Zhao, Shitong Wang, Pin Cao, Dong Liu, Lu Li, Lu Yan, Chen Li, Shibin Xie, Yang Li, Yangjie Chen","doi":"10.1117/12.2181182","DOIUrl":"https://doi.org/10.1117/12.2181182","url":null,"abstract":"The high-resolution detecting system based on machine vision for defects on large aperture and super-smooth surface uses a novel ring telecentric lighting optical system detecting the defects on the sample all round and without blind spots. The scattering light induced by surface defects enters the adaptive and highly zoom microscopic scattering dark-field imaging system for defect detecting and then forms digital images. Sub-aperture microscopic scanning sampling and fast stitching on the surface is realized by using precise multi-axis shifting guided scanning system and a standard comparison board based upon binary optics is used to implement fast calibration of micron-dimension defects detected actually. The pattern recognition technology of digital image processing which can automatically output digitalized surface defects statements after scaling is established to comprehensively evaluate defects. This system which can reach micron-dimension defect resolution can achieve detections of large aperture components of 850 mm × 500 mm, solve the durable problem of subjective uncertainty brought in by human visual detection of defects and achieve quantitative detection of defects with machine vision.","PeriodicalId":380636,"journal":{"name":"Precision Engineering Measurements and Instrumentation","volume":"338 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124310668","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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