International Symposium on Laser Metrology最新文献

A low-cost antenna reflector shape and distortion measuring system with high accuracy 一种低成本、高精度的天线反射面形状和畸变测量系统

International Symposium on Laser Metrology Pub Date : 2008-10-03 DOI: 10.1117/12.814543

Xudong Li, Hongzhi Jiang, Jie Zhou, Dong Li, Huijie Zhao

引用次数: 0

Crack displacement sensing and measurement in concrete using circular grating moire fringes and pattern matching 基于圆光栅云纹条纹和模式匹配的混凝土裂缝位移传感与测量

International Symposium on Laser Metrology Pub Date : 2008-10-03 DOI: 10.1117/12.814583

H. Chan, K. Yen, M. Ratnam

{"title":"Crack displacement sensing and measurement in concrete using circular grating moire fringes and pattern matching","authors":"H. Chan, K. Yen, M. Ratnam","doi":"10.1117/12.814583","DOIUrl":"https://doi.org/10.1117/12.814583","url":null,"abstract":"The moire method has been extensively studied in the past and applied in various engineering applications. Several techniques are available for generating the moire fringes in these applications, which include moire interferometry, projection moire, shadow moire, moire deflectometry etc. Most of these methods use the superposition of linear gratings to generate the moire patterns. The use of non-linear gratings, such as circular, radial and elongated gratings has received less attention from the research community. The potential of non-linear gratings in engineering measurement has been realized in a limited number of applications, such as rotation measurement, measurement of linear displacement, measurement of expansion coefficients of materials and measurement of strain distribution. In this work, circular gratings of different pitch were applied to the sensing and measurement of crack displacement in concrete structures. Gratings of pitch 0.50 mm and 0.55 mm were generated using computer software and attached to two overlapping acrylic plates that were bonded to either side of the crack. The resulting moire patterns were captured using a standard digital camera and compared with a set of reference patterns generated using a precision positioning stage. Using several image pre-processing stages, such as filtering and morphological operations, and pattern matching the magnitude displacements along two orthogonal axes can be detected with a resolution of 0.05 mm.","PeriodicalId":191475,"journal":{"name":"International Symposium on Laser Metrology","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117334032","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}

引用次数: 9

Temporal Paul wavelet analysis for phase retrieval using shadow moire technique 基于阴影云纹技术的时域保罗小波分析相位恢复

International Symposium on Laser Metrology Pub Date : 2008-10-03 DOI: 10.1117/12.814585

H. Niu, C. Quan, C. Tay

引用次数: 0

High throughput measurement techniques for wafer level yield inspection of MEMS devices MEMS晶圆级良率检测的高通量测量技术

International Symposium on Laser Metrology Pub Date : 2008-10-03 DOI: 10.1117/12.814724

O. Varela Pedreira, T. Lauwagie, J. de Coster, L. Haspeslagh, A. Witvrouw, I. De Wolf

引用次数: 9

Frequency-shifting method for phase retrieval from fringe patterns 从条纹图中提取相位的移频方法

International Symposium on Laser Metrology Pub Date : 2008-10-03 DOI: 10.1117/12.814522

Haixia Wang, K. Qian, Wenjing Gao

引用次数: 1

Optical bi-sensorial measurement system for production control of extruded profiles 用于挤压型材生产控制的光学双传感器测量系统

International Symposium on Laser Metrology Pub Date : 2008-10-03 DOI: 10.1117/12.814567

A. Weckenmann, J. Bernstein

{"title":"Optical bi-sensorial measurement system for production control of extruded profiles","authors":"A. Weckenmann, J. Bernstein","doi":"10.1117/12.814567","DOIUrl":"https://doi.org/10.1117/12.814567","url":null,"abstract":"Extruded profiles are semi-finished products (made out of steel, brass, aluminum, synthetics...) which are appointed for wide applications in manufacturing of technical products. As yet used optical sensors in process control working to the shading technology detect the object's shadow orthographically to the axis of illumination. As a consequence they record it unattached by the profiles coat in measurement range at any point of the measured profile with high precision. As a matter of fact, concave zones cannot be captured. Alternatively the measurement of concave zones can be arranged by light-section systems. These do not comply with the required accuracy, are comparatively slow and moreover affected by dislocations of the section of the profile. A measurement system including a light-section and a shading system combines the advantages of both optical systems. It is to serve with a reliable conception for the assembly of a bi-sensorial measurement system consisting of both systems as well as suitable methods of analysis for the in-line inspection of concave profiles. As a result it contains conclusions concerning requirements of the light source, the arrangement of this source and the cameras, obtainable precision and sampling rate as well as the essential synchronization of both systems. After designing an appropriate prototype, the selected light-section system and the shading system will be synchronized and aligned. Therefore, the metered geometrical data will be merged for the evaluation of form deviation. So, developed and adapted software supports and contains proposals to the uncertainty after successful tests. The system and a calibration method will be proved in production where robustness will be a most critical despite of heat, dust and vibrations. The target uncertainty of less than 0.1 mm at every section of the profiles coat has to be met.","PeriodicalId":191475,"journal":{"name":"International Symposium on Laser Metrology","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129375177","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}

引用次数: 1

New simplified measuring method for distributed low-level birefringence 分布式低能级双折射的一种简化测量方法

International Symposium on Laser Metrology Pub Date : 2008-10-03 DOI: 10.1117/12.814536

K. Gomi, Tomoyuki Suzuki, Y. Niitsu, K. Ichinose

引用次数: 0

Microlens testing: an application 微透镜测试:一个应用

International Symposium on Laser Metrology Pub Date : 2008-10-03 DOI: 10.1117/12.814595

Hooi Leng Ng-Lee, S. C. Goh, C. Ranjit, .. Maryanto, Jie Ying Sarah Ng, A. Asundi

引用次数: 0

Processing of digital holograms for size measurements of microparticlese 微粒子尺寸测量用数字全息图的处理

International Symposium on Laser Metrology Pub Date : 2008-10-03 DOI: 10.1117/12.814578

E. Darakis, Taslima Khanam, A. Rajendran, V. Kariwala, A. Asundi, T. Naughton

{"title":"Processing of digital holograms for size measurements of microparticlese","authors":"E. Darakis, Taslima Khanam, A. Rajendran, V. Kariwala, A. Asundi, T. Naughton","doi":"10.1117/12.814578","DOIUrl":"https://doi.org/10.1117/12.814578","url":null,"abstract":"Digital holography has been reported as an effective tool for particle analysis. Other image-based techniques have small depth of focus allowing only 2D analysis at microscopic level. On the other hand, digital holography offers the ability to study volume samples from a single recording as reconstructions at different depths can be obtained. This paper focuses on the processing of the digital hologram that follows its recording in order to obtain particle size. We present a stepwise processing procedure with discussion on aspects such as reconstruction, background correction, segmentation, focusing, magnification and particles' feature extraction. Solutions to common obstacles faced during particle analysis which include ways to obtain fixed size reconstructions, automatically determine the threshold value, calculate magnification, and locate particles' depth position using effective focusing metrics are highlighted. Real holograms of microparticles are used to illustrate and explain the different stages of the procedure. Experimental results show that the proposed algorithm can effectively extract particle size information from recorded digital holograms.","PeriodicalId":191475,"journal":{"name":"International Symposium on Laser Metrology","volume":"80 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126386912","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}

引用次数: 12

Hardware-based error compensation in 3D optical metrology systems 基于硬件的三维光学测量系统误差补偿

International Symposium on Laser Metrology Pub Date : 2008-10-03 DOI: 10.1117/12.814693

K. Harding

引用次数: 4