The Experts below are selected from a list of 264 Experts worldwide ranked by ideXlab platform
Regor L Saulsberry - One of the best experts on this subject based on the ideXlab platform.
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development of critical Profilometers to meet current and future nasa composite overwrapped pressure vessel copv inspection needs
2012Co-Authors: Regor L Saulsberry, Charles NicholsAbstract:This project is part of a multi-center effort to develop and validate critical NDE techniques which can be implemented into current and future NASA spacecraft COPV manufacturing processes. After decades of COPV development, manufacturing variance is still high and has necessitated higher safety factors and additional mass to be flown on spacecraft (reducing overall performance). Additionally, the NASA Engineering and Safety Center (NESC) indicated that nondestructive evaluation (NDE) was not adequately implemented during Shuttle and International Space Station (ISS) COPV manufacturing and provisions were not made for on-going structural integrity and health checks during the various spacecraft programs. This project helps to provide additional data needed to help address these issues. This project seeks to develop and install internal and external laser Profilometers at COPV manufacturing facilities to provide data needed to improve COPV quality and consistency. This project also investigates other scanning techniques that will enhance the system to more completely meet manufacturing needs, thus transforming the profilometer into what has been termed the "Universal Manufacturing COPV Scanner".
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develop critical Profilometers to meet current and future composite overwrapped pressure vessel copv interior inspection needs
2010Co-Authors: Regor L SaulsberryAbstract:The objective of this project is to develop laser profilometer technology that can efficiently inspect and map the inside of composite pressure vessels for flaws such as liner buckling, pitting, or other surface imperfections. The project will also provide Profilometers that can directly support inspections of flight vessels during development and qualification programs and subsequently be implemented into manufacturing inspections to screen out vessels with "out of family" liner defects. An example interior scan of a carbon overwrapped bottle is shown in comparison to an external view of the same bottle (Fig. 1). The internal scan is primarily of the cylindrical portion, but extends about 0.15 in. into the end cap area.
Matthew J. Baker - One of the best experts on this subject based on the ideXlab platform.
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neural network digital fringe calibration technique for structured light Profilometers
Applied Optics, 2007Co-Authors: Matthew J. Baker, Jiangtao Xi, Joe F. ChicharoAbstract:We present a novel neural network signal calibration technique to improve the performance of triangulation-based structured light Profilometers based on digital projection. The performance of such Profilometers is often hindered by the capture of aberrated pattern intensity distributions, and hence we address this problem by employing neural networks in a signal mapping approach. We exploit the generalization and interpolation capabilities of a feed-forward backpropagation neural network to map from distorted fringe data to nondistorted data. The performance of the calibration technique is gauged both through simulation and experimentation, with simulation results indicating that accuracy can be improved by more than 80%. The technique requires just one image cross section for calibration and hence is ideal for rapid profiling applications.
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Fringe Calibration using Neural Network Signal Mapping for Structured Light Profilometers
2006 International Symposium on Intelligent Signal Processing and Communications, 2006Co-Authors: Matthew J. Baker, Jiangtao Xi, Joe F. ChicharoAbstract:We present a novel neural network signal calibration technique to improve the performance of triangulation based structured light Profilometers. The performance of such Profilometers is often hindered by the capture of noisy and aberrated pattern intensity distributions. We address this problem by employing neural networks and a spatial digital filter in a signal mapping approach. The performance of the calibration technique is gauged through both simulation and experimentation, with simulation results indicating that accuracy can be improved by more than 80%
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A contrast between DLP and LCD digital projection technology for triangulation based phase measuring optical Profilometers
Two- and Three-Dimensional Methods for Inspection and Metrology III, 2005Co-Authors: Matthew J. Baker, Joe Chicharo, Jiangtao Xi, Enbang LiAbstract:With the growing demand for high speed and dynamic 3D profiling for\napplications such as animation, face recognition and machine vision,\nwe have seen Digital Video Projection (DVP) emerge as the preferred\nprojection technology. In addition to the robust qualities DVP sources\noffer, many researchers are adopting the technology on the merits\nof higher resolutions, contrast ratios and sharper images, all of\nwhich are characteristic of the highly developing projection technology.\nHowever, in regard to the specific application of triangulation\nbased optical Profilometers, DVP lacks predominantly in pattern\ngeometric structure and also suffers from colour channel coupling\nissues. The purpose of this paper is to review the functionality\nand contrast the two chief DVP technologies, Liquid Crystal Display\n(LCD) and Digital Light Processing (DLP) from the specific viewpoint\nof a triangulation based phase measuring profilometer. Experimental\nverification of the performance of each projection technology is\nprovided and finally some suggestions on projection technologies\nfor single and multichannel phase measuring profilometry applications\nis offered.
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Optimisation of triangulation based optical Profilometers utilising digital video projection technology
2005 IEEE LEOS Annual Meeting Conference Proceedings, 2005Co-Authors: Matthew J. Baker, Joe Chicharo, Jiangtao Xi, Enbang LiAbstract:In this work, an optical configuration is proposed to increase the spatial resolution of triangulation based Profilometers utilising digital video projection (DVP) and also facilitate increased performance of defocusing optimisation schemes. The performance of the proposed optical configuration by contrasting experimental results obtained from a typical triangulation based profilometer optical configuration is demonstrated
N A Tsalikova - One of the best experts on this subject based on the ideXlab platform.
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modern dental cad cam systems with intraoral 3d Profilometers
Measurement Techniques, 2010Co-Authors: G G Levin, G N Vishnyakov, K E Loshchilov, T I Ibragimov, Yu I Lebedenko, N A TsalikovaAbstract:Modern CAD/CAM dental systems that incorporate an intraoral 3D profilometer are considered. The operating principle of the device and its functionality features are described. The first domestically produced intraoral 3D profilometer for a CAD/CAM dental system, which was designed at the All-Russia Research Institute of Optophysical Measurements, is presented.
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Modern dental CAD/CAM systems with intraoral 3D Profilometers
Measurement Techniques, 2010Co-Authors: G G Levin, G N Vishnyakov, K E Loshchilov, T I Ibragimov, I. Yu. Lebedenko, N A TsalikovaAbstract:Modern CAD/CAM dental systems that incorporate an intraoral 3D profilometer are considered. The operating principle of the device and its functionality features are described. The first domestically produced intraoral 3D profilometer for a CAD/CAM dental system, which was designed at the All-Russia Research Institute of Optophysical Measurements, is presented.
Jiangtao Xi - One of the best experts on this subject based on the ideXlab platform.
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neural network digital fringe calibration technique for structured light Profilometers
Applied Optics, 2007Co-Authors: Matthew J. Baker, Jiangtao Xi, Joe F. ChicharoAbstract:We present a novel neural network signal calibration technique to improve the performance of triangulation-based structured light Profilometers based on digital projection. The performance of such Profilometers is often hindered by the capture of aberrated pattern intensity distributions, and hence we address this problem by employing neural networks in a signal mapping approach. We exploit the generalization and interpolation capabilities of a feed-forward backpropagation neural network to map from distorted fringe data to nondistorted data. The performance of the calibration technique is gauged both through simulation and experimentation, with simulation results indicating that accuracy can be improved by more than 80%. The technique requires just one image cross section for calibration and hence is ideal for rapid profiling applications.
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Fringe Calibration using Neural Network Signal Mapping for Structured Light Profilometers
2006 International Symposium on Intelligent Signal Processing and Communications, 2006Co-Authors: Matthew J. Baker, Jiangtao Xi, Joe F. ChicharoAbstract:We present a novel neural network signal calibration technique to improve the performance of triangulation based structured light Profilometers. The performance of such Profilometers is often hindered by the capture of noisy and aberrated pattern intensity distributions. We address this problem by employing neural networks and a spatial digital filter in a signal mapping approach. The performance of the calibration technique is gauged through both simulation and experimentation, with simulation results indicating that accuracy can be improved by more than 80%
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A contrast between DLP and LCD digital projection technology for triangulation based phase measuring optical Profilometers
Two- and Three-Dimensional Methods for Inspection and Metrology III, 2005Co-Authors: Matthew J. Baker, Joe Chicharo, Jiangtao Xi, Enbang LiAbstract:With the growing demand for high speed and dynamic 3D profiling for\napplications such as animation, face recognition and machine vision,\nwe have seen Digital Video Projection (DVP) emerge as the preferred\nprojection technology. In addition to the robust qualities DVP sources\noffer, many researchers are adopting the technology on the merits\nof higher resolutions, contrast ratios and sharper images, all of\nwhich are characteristic of the highly developing projection technology.\nHowever, in regard to the specific application of triangulation\nbased optical Profilometers, DVP lacks predominantly in pattern\ngeometric structure and also suffers from colour channel coupling\nissues. The purpose of this paper is to review the functionality\nand contrast the two chief DVP technologies, Liquid Crystal Display\n(LCD) and Digital Light Processing (DLP) from the specific viewpoint\nof a triangulation based phase measuring profilometer. Experimental\nverification of the performance of each projection technology is\nprovided and finally some suggestions on projection technologies\nfor single and multichannel phase measuring profilometry applications\nis offered.
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Optimisation of triangulation based optical Profilometers utilising digital video projection technology
2005 IEEE LEOS Annual Meeting Conference Proceedings, 2005Co-Authors: Matthew J. Baker, Joe Chicharo, Jiangtao Xi, Enbang LiAbstract:In this work, an optical configuration is proposed to increase the spatial resolution of triangulation based Profilometers utilising digital video projection (DVP) and also facilitate increased performance of defocusing optimisation schemes. The performance of the proposed optical configuration by contrasting experimental results obtained from a typical triangulation based profilometer optical configuration is demonstrated
David Bartlett - One of the best experts on this subject based on the ideXlab platform.
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surface roughness of impression materials and dental stones scanned by non contacting laser profilometry
Dental Materials, 2009Co-Authors: Jose Manuel Rodriguez, Richard Curtis, David BartlettAbstract:Abstract Objective To analyze differences in the way dental materials digitize on a non-contacting laser profilometer (NCLP). Methods Three Type IV dental stones and 15 impression materials were mixed according to the manufacturer's instructions and expressed against a glass block to record its surface characteristics. From each material an area of 6 × 40 mm was scanned on the NCLP and the Ra, Rq and Rt roughness values measured from 20 randomly selected transverse profiles. The surface of the impression materials was subsequently poured in Moonstone™ (Bracon Ltd., Etchingham, England) dental stone and the same roughness values obtained from these casts. Differences in roughness values from the dental materials were compared using ANOVA and differences in roughness between impression materials and the Moonstone™ casts compared using paired t -tests. Results There were significant differences in roughness values between individual materials within each type (impression material or dental stone) ( p p p Significance Digitization of dental materials on optical Profilometers was affected by color and transparency.
