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Dissertations / Theses on the topic 'Inspection of dimensions'
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1
Hřib, Jan. "Automatizovaný systém pro skenování konstrukčních dílů." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2021. http://www.nusl.cz/ntk/nusl-442450.
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The aim of this thesis is to design an automated scanning system for components for the purpose of inspecting their dimensions and tolerances. The theoretical introduction provides the reader with basic information on the topic of 3D scanning. The work also includes the design of own scanning system. The greatest attention is paid to the design of a program using the PCL library. The aim of the program is automatic processing of data from a 3D scanner and evaluation of the required dimensions of the scanned component. The final part of the work is devoted to testing the proposed solution.
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Ferguson, Bradley Stuart. "Three dimensional T-Ray inspection systems /." Title page, Table of contents and abstract only, 2004. http://web4.library.adelaide.edu.au/theses/09PH/09phf3521.pdf.
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Chung, Kyung Ho. "Application of Augmented Reality to Dimensional and Geometric Inspection." Diss., Virginia Tech, 2002. http://hdl.handle.net/10919/26326.
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Ensuring inspection performance is not a trivial design problem, because inspection is a complex and difficult task that tends to be error-prone, whether performed by human or by automated machines. Due to economical or technological reasons, human inspectors are responsible for inspection functions in many cases. Humans, however, are rarely perfect. A system of manual inspection was found to be approximately 80-90% effective, thus allowing non-confirming parts to be processed (Harris & Chaney, 1969; Drury, 1975). As the attributes of interest or the variety of products increases, the complexity of an inspection task increases. The inspection system becomes less effective because of the sensory and cognitive limitations of human inspectors. Any means that can support or aid the human inspectors is necessary to compensate for inspection difficulty.
Augmented reality offers a new approach in designing an inspection system as a means to augment the cognitive capability of inspectors. To realize the potential benefits of AR, however the design of AR-aided inspection requires a through understanding of the inspection process as well as AR technology. The cognitive demands of inspection and the capabilities of AR to aid inspectors need to be evaluated to decide when and how to use AR for a dimensional inspection.
The objectives of this study are to improve the performance of a dimensional inspection task by using AR and to develop guidelines in designing an AR-aided inspection system. The performance of four inspection methods (i.e., manual, 2D-aided, 3D-aided, and AR-aided inspections) was compared in terms of inspection time and measurement accuracy. The results suggest that AR might be an effective tool that reduces inspection time. However, the measuring accuracy was basically the same across all inspection methods. The questionnaire results showed that the AR and 3D-aided inspection conditions are preferred over the manual and 2D-aided inspection. Based on the results, four design guidelines were formed in using AR technology for a dimensional inspection.
Ph. D.
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Pendse, Nachiket Vishwas. "An effective dimensional inspection method based on zone fitting." Texas A&M University, 2004. http://hdl.handle.net/1969.1/3239.
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Coordinate measuring machines are widely used to generate data points from an actual surface. The generated measurement data must be analyzed to yield critical geometric deviations of the measured part according to the requirements specified by the designer. However, ANSI standards do not specify the methods that should be used to evaluate the tolerances. The coordinate measuring machines employ different verification algorithms which may yield different results. Functional requirements or assembly conditions on a manufactured part are normally translated into geometric constraints to which the part must conform. Minimum zone evaluation technique is used when the measured data is regarded as an exact copy of the actual surface and the tolerance zone is represented as geometric constraints on the data.
In the present study, a new zone-fitting algorithm is proposed. The algorithm evaluates the minimum zone that encompasses the set of measured points from the actual surface. The search for the rigid body transformation that places the set of points in the zone is modeled as a nonlinear optimization problem. The algorithm is employed to find the form tolerance of 2-D (line, circle) as well as 3-D geometries (cylinder). It is also used to propose an inspection methodology for turbine blades. By constraining the transformation parameters, the proposed methodology determines whether the points measured at the 2-D cross-sections fit in the corresponding tolerance zones simultaneously.
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Cheetham, Andrew. "Simulation of a multi-dimensional pattern classifier." Thesis, Nottingham Trent University, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.297128.
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Lloyd, Timothy Brian. "Surface extraction from coordinate measurement data to facilitate dimensional inspection." Thesis, Georgia Institute of Technology, 1999. http://hdl.handle.net/1853/15815.
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Wander, Joseph M. "The application of Moire interferometry to automated 3-dimensional inspection." Thesis, Massachusetts Institute of Technology, 1985. http://hdl.handle.net/1721.1/15264.
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Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1985.MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING.
Includes bibliographical references.
by Joseph M. Wander.
M.S.
8
Morton, Carrie A. (Carrie Anne). "A collaborative tool for the inspection of three dimensional design." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/43378.
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Rajkumar, Devaraj. "Decomposition of measured contours into geometric features for dimensional inspection." PDXScholar, 1990. https://pdxscholar.library.pdx.edu/open_access_etds/4149.
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Image processing systems used in Vision Assisted Dimensional Inspection usually output a set of boundary pixels representing the part edges. This boundary information must be divided into several subsets representing the various edges of the actual object, so that comparisons with the nominal part can be made.
The purpose of this project is to devise a method to divide the set of pixels obtained from the image processing system into subsets of pixels. Each of these subsets represent an edge in the contour of the actual object. This method must also detect transition points between the adjacent features. This project addresses only planar contours which are composed of straight and circular edges. Two new algorithms have been developed, the first algorithm detects the transition points involving straight edges and the second algorithm finds the transition points when circular features are involved. In addition, the measured features are also matched with their nominal counterparts. The performance of these algorithms are demonstrated by simulated as well as images from the vision system.
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Marshall, Andrew David. "The automatic inspection of machined parts using three-dimensional range data and model based matching techniques." Thesis, Cardiff University, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.254595.
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Nakazawa, Takeshi. "THREE-DIMENSIONAL NON-CONTACT SURFACE PROFILERS FOR SEMICONDUCTOR IC PACKAGE INSPECTION." Diss., The University of Arizona, 2011. http://hdl.handle.net/10150/205472.
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The subject of this dissertation is the development of three-dimensional (3D) surface profilers for semiconductor back-end inspection. The value of this study is: 1) to provide a new phase-to-height relationship for Fourier Transform Profilometry (FTP) that is universal as it allows alternate FTP system architectures for a micrometer scale object measurement, and 2) to provide a new method for full field substrate warpage and ball grid array (BGA) coplanarity inspection using machine vision. The desire to increase electronic device performance has resulted in denser and smaller IC packaging. As the dimensions of the devices decrease, the requirements for substrate flatness and surface quality become critical in avoiding device failure. For a high yield production, there is an increasing demand in the requirement for the dimensional verification of height, which requires 3D inspection. Based on the current demands from the semiconductor industry, this dissertation addresses the development of fast in-line surface profilers for large volume IC package inspection. Specifically, this dissertation studies two noncontact surface profilers. The first profiler is based on FTP for measuring the IC package front surface, the silicon die and the epoxy underfill profile. The second profiler is based on stereovision and it is intended for inspecting the BGA coplanarity and the substrate warpage. A geometrical shape based matching algorithm is also developed for finding point correspondences between IC package images. The FTP profiler provides a 1 σRMS error of about 4 μm for an IC package sample in an area of 14 mm x 6.5 mm with a 0.13 second data acquisition time. For evaluating the performance of the stereovision system, the linearity between our system and a confocal microscope is studied by measuring a particular IC sample with an area of 38 mm x 28.5 mm. The correlation coefficient is 0.965 and the 2σdifference in the two methods is 26.9 μm for the warpage measurement. For BGA coplanarity inspection the correlation coefficient is 0.952 and the 2difference is 31.2 μm. Data acquisition takes about 0.2 seconds for full field measurements.
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Wang, Jaiwei. "A dedicated computer vision system for dimensional inspection of engineering components." Thesis, University of Huddersfield, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.338604.
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Davis, Tyler A. "Flexible machine tool control for direct, in-process dimensional part inspection /." Diss., CLICK HERE for online access, 2004. http://contentdm.lib.byu.edu/ETD/image/etd478.pdf.
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Davis, Tyler Addison. "Flexible machine tool control for direct, in-process dimensional part inspection." BYU ScholarsArchive, 2004. https://scholarsarchive.byu.edu/etd/139.
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For some time now coordinate measuring machines have been an integral part of the shop floor. The goal has been to make coordinate measuring machines (CMMs) into tools that can easily be used by machinists to improve their manufacturing capabilities. The value of a CMM as a quality control tool is undisputed. Now efforts are being made to further reduce the time and cost of measurement by reducing the physical distance between machining and measuring processes. The ability to reduce that distance to zero and measure a part directly on the chip-making machine has been a goal for many years. Dimensional inspection of parts is primarily conducted by coordinate measuring machines operating on motion instructions from task planning software. The research in direct machining and control (DMAC) at BYU has identified a potential application of CMM technologies on existing machine tools. To prove that a machine tool can be controlled as a CMM with the DMAC controller, this research will integrate the software package PC-DMIS provided by Wilcox Associates, Inc. with a DMAC controller provided by Direct Controls, Inc. to conduct in-process dimensional inspection of parts as they are being machined. This process is referred to as DirectCMM because it will link the DMAC controller directly to PC-DMIS without need for post-processing. This thesis will lay the groundwork for future efforts at developing systems that utilize in-process part inspection to dynamically correct computer aided manufacturing (CAM) process plans. To aid future efforts at dynamic CAM process updating, a software interface specification will be created for passing measurement data between CMM and CAD/CAM software packages. A CMM control specification will also be created to provide a standard method for controlling coordinate measuring machines with the DMAC controller. Possible methods for dynamic CAD/CAM updating will be explored.
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Yau, Hong-Tzong. "The development of an intelligent dimensional inspection environment using coordinate measuring machines /." Connect to resource, 1991. http://rave.ohiolink.edu/etdc/view.cgi?acc%5Fnum=osu1244135873.
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Yau, Hong-Tzong. "The development of an intelligent dimensional inspection environment using coordiante measuring machines." The Ohio State University, 1991. http://rave.ohiolink.edu/etdc/view?acc_num=osu1244135873.
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Makem, J. E. "Virtual Net-Shape Forging of Aerofoil Blades - Dimensional Inspection and Shape Sensitivity to Process Variables." Thesis, Queen's University Belfast, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.517543.
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Sadaoui, Sif Eddine. "Inspection dimensionnelle - Une approche multi-capteurs pour la vérification des spécifications géométriques." Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLN020/document.
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L'inspection dimensionnelle, qui consiste à vérifier la conformité géométrique des pièces vis-à-vis des spécifications, est une étape essentielle dans le cycle de vie des produits. Elle s’appuie de plus en plus sur la mesure multi-capteurs qui permet un gain de temps certain. Néanmoins, le gain de temps n'a de sens que si la qualité des résultats respecte le besoin métrologique. En effet, la mise en œuvre combinée de capteurs de technologie et de caractéristiques différentes engendre un certain nombre de problèmes qui affectent directement la qualité de la mesure. Dans ce travail, une approche d'inspection automatique utilisant un scanner combinant un capteur à contact avec un capteur laser-plan monté sur une MMT est proposée. Cette approche cherche à utiliser au mieux les capacités de chacun des capteurs, en privilégiant la mesure avec le capteur laser-plan dès lors que la qualité requise est obtenue pour un gain de temps. L’approche consiste à définir une séquence d’opérations de mesure de surfaces qui portent des spécifications, appelées entités d’inspection.Partant d'un ensemble d'orientations du scanner, la séquence d'opérations est établie pour chaque orientation par évaluation de l'aptitude du capteur laser puis celle du palpeur à mesurer les surfaces avec la qualité nécessaire. La gamme d'inspection est complétée par la définition optimale de la trajectoire du capteur laser-plan et celle du palpeur pour chaque orientation. La trajectoire finale exécutée sur machine MMT est obtenue par transformation et assemblage des deux trajectoires. À l'issue de l'exécution, la mesure avec les deux capteurs conduit à deux nuages de points hétérogènes qu’il convient de traiter avant l’évaluation finale des spécificationsDimensional inspection, which consists in verifying the geometric conformity of parts in terms of specifications, is an essential step in the product life cycle. Recently, dimensional inspection has been increasingly based on multi-sensor measurement that allows a significant time saving. However, time saving is only meaningful if the quality of the results respects the metrological requirements. Indeed, the combined use of sensors of different technologies and characteristics generates issues that affect the measurement quality. In this work, an automatic inspection approach using a scanner combining a contact sensor with a laser-plane sensor mounted on a CMM is proposed. This approach aims to best use the abilities of each of the sensors, giving priority to measurement with the laser-plan sensor as soon as the required quality is obtained for time saving. The approach consists in defining a sequence of surface measurement operations that have specifications, called inspection features.Starting from a set of scanner orientations, the sequence of operations is established for each orientation by evaluating the ability of the laser sensor and then that of the probe to measure surfaces with the required quality. The inspection plan is completed by the optimal definition of the laser-plane sensor path and the probe path for each orientation. The final path executed on the CMM machine is obtained by transforming and assembling the two paths. At the end of the execution, the measurement with the two sensors leads to two heterogeneous point clouds that must be processed before the final evaluation of the specifications
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Hons, Viktor. "Detekce vad s využitím smart kamery." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2021. http://www.nusl.cz/ntk/nusl-442536.
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This thesis deals with the application of smart cameras and verification of its functions. In the first part the term smart camera is defined, the parts of it and the most common applications are presented. A review of smart cameras from the different manufactures on the market is made. After selection of the proper camera model three task from real industrial application are specified – inspection of capacitor print, inspection of beer label and dimension measurement. With the picked camera the tasks are performed, including the layout of workplace, scene and lighting. Further the reliability is tested together with the successfulness and the speed of designed solution.
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Wong, Ching-Li Jimmy. "Computer integrated dimensional inspection of manufactured parts with sculptured surfaces using CAD and coordinate measuring machine /." The Ohio State University, 1989. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487672631601377.
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Koeppe, Ralf. "A comparative study of the performance of various image analysis methods for dimensional inspection with vision systems." PDXScholar, 1989. https://pdxscholar.library.pdx.edu/open_access_etds/3930.
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Dimensional inspection with Vision Systems requires a careful selection of image analysis methods in order to obtain accurate information about the geometry of the parts to be measured.
The purpose of this project is to study, implement and compare different image evaluation methods and to show their strengths and weaknesses with respect to dimensional inspection. Emphasis is made on the inspection of circular features. The criteria of comparison for these methods are discussed. Using synthetically generated images, various analysis methods are compared and conclusions for their use are drawn. Results of the comparison show that the selection of a method has to be done with regard to the noise level of the measurement. Finally, a computationally fast calibration algorithm is studied and implemented .
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Carlson, Shane A. "Development of a Variational Part Model Using In-Process Dimensional Measurement Error." Diss., CLICK HERE for online access, 2006. http://contentdm.lib.byu.edu/ETD/image/etd1341.pdf.
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Wells, Lee Jay. "Advancing Manufacturing Quality Control Capabilities Through The Use Of In-Line High-Density Dimensional Data." Diss., Virginia Tech, 2014. http://hdl.handle.net/10919/24865.
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Through recent advancements in high-density dimensional (HDD) measurement technologies, such as 3D laser scanners, data-sets consisting of an almost complete representation of a manufactured part's geometry can now be obtained. While HDD data measurement devices have traditionally been used in reverse engineering application, they are beginning to be applied as in-line measurement devices. Unfortunately, appropriate quality control (QC) techniques have yet to be developed to take full advantage of this new data-rich environment and for the most part rely on extracting discrete key product characteristics (KPCs) for analysis. In order to maximize the potential of HDD measurement technologies requires a new quality paradigm. Specifically, when presented with HDD data, quality should not only be assessed by discrete KPCs but should consider the entire part being produced, anything less results in valuable data being wasted.
This dissertation addresses the need for adapting current techniques and developing new approaches for the use of HDD data in manufacturing systems to increase overall quality control (QC) capabilities. Specifically, this research effort focuses on the use of HDD data for 1) Developing a framework for self-correcting compliant assembly systems, 2) Using statistical process control to detect process shifts through part surfaces, and 3) Performing automated part inspection for non-feature based faults. The overarching goal of this research is to identify how HDD data can be used within these three research focus areas to increase QC capabilities while following the principles of the aforementioned new quality paradigm.Ph. D.
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Ji, Qiang. "A three dimensional computer vision system for inspecting the geometric tolerances of circular machine features /." Thesis, Connect to this title online; UW restricted, 1998. http://hdl.handle.net/1773/5953.
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Xie, Tuqiang. "Development of an opto-fluidic probe for on-line noncontact dimensional inspection and tool condition monitoring in a hazardous manufacturing environment." Thesis, Brunel University, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.324552.
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Ben, Abdallah Hamdi. "Inspection d'assemblages aéronautiques par vision 2D/3D en exploitant la maquette numérique et la pose estimée en temps réel Three-dimensional point cloud analysis for automatic inspection of complex aeronautical mechanical assemblies Automatic inspection of aeronautical mechanical assemblies by matching the 3D CAD model and real 2D images." Thesis, Ecole nationale des Mines d'Albi-Carmaux, 2020. http://www.theses.fr/2020EMAC0001.
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Cette thèse s'inscrit dans le contexte du développement d'outils numériques innovants au service de ce qui est communément désigné par Usine du Futur. Nos travaux de recherche ont été menés dans le cadre du laboratoire de recherche commun "Inspection 4.0" entre IMT Mines Albi/ICA et la Sté DIOTA spécialisée dans le développement d'outils numériques pour l'Industrie 4.0. Dans cette thèse, nous nous sommes intéressés au développement de systèmes exploitant des images 2D ou des nuages de points 3D pour l'inspection automatique d'assemblages mécaniques aéronautiques complexes (typiquement un moteur d'avion). Nous disposons du modèle CAO de l'assemblage (aussi désigné par maquette numérique) et il s'agit de vérifier que l'assemblage a été correctement assemblé, i.e que tous les éléments constituant l'assemblage sont présents, dans la bonne position et à la bonne place. La maquette numérique sert de référence. Nous avons développé deux scénarios d'inspection qui exploitent les moyens d'inspection développés par DIOTA : (1) un scénario basé sur une tablette équipée d'une caméra, portée par un opérateur pour un contrôle interactif temps-réel, (2) un scénario basé sur un robot équipé de capteurs (deux caméras et un scanner 3D) pour un contrôle totalement automatique. Dans les deux scénarios, une caméra dite de localisation fournit en temps-réel la pose entre le modèle CAO et les capteurs mis en œuvre (ce qui permet de relier directement la maquette numérique 3D avec les images 2D ou les nuages de points 3D analysés). Nous avons d'abord développé des méthodes d'inspection 2D, basées uniquement sur l'analyse d'images 2D puis, pour certains types d'inspection qui ne pouvaient pas être réalisés à partir d'images 2D (typiquement nécessitant la mesure de distances 3D), nous avons développé des méthodes d'inspection 3D basées sur l'analyse de nuages de points 3D. Pour l'inspection 3D de câbles électriques présents au sein de l'assemblage, nous avons proposé une méthode originale de segmentation 3D des câbles. Nous avons aussi traité la problématique de choix automatique de point de vue qui permet de positionner le capteur d'inspection dans une position d'observation optimale. Les méthodes développées ont été validées sur de nombreux cas industriels. Certains des algorithmes d’inspection développés durant cette thèse ont été intégrés dans le logiciel DIOTA Inspect© et sont utilisés quotidiennement chez les clients de DIOTA pour réaliser des inspections sur site industrielThis thesis makes part of a research aimed towards innovative digital tools for the service of what is commonly referred to as Factory of the Future. Our work was conducted in the scope of the joint research laboratory "Inspection 4.0" founded by IMT Mines Albi/ICA and the company DIOTA specialized in the development of numerical tools for Industry 4.0. In the thesis, we were interested in the development of systems exploiting 2D images or (and) 3D point clouds for the automatic inspection of complex aeronautical mechanical assemblies (typically an aircraft engine). The CAD (Computer Aided Design) model of the assembly is at our disposal and our task is to verify that the assembly has been correctly assembled, i.e. that all the elements constituting the assembly are present in the right position and at the right place. The CAD model serves as a reference. We have developed two inspection scenarios that exploit the inspection systems designed and implemented by DIOTA: (1) a scenario based on a tablet equipped with a camera, carried by a human operator for real-time interactive control, (2) a scenario based on a robot equipped with sensors (two cameras and a 3D scanner) for fully automatic control. In both scenarios, a so-called localisation camera provides in real-time the pose between the CAD model and the sensors (which allows to directly link the 3D digital model with the 2D images or the 3D point clouds analysed). We first developed 2D inspection methods, based solely on the analysis of 2D images. Then, for certain types of inspection that could not be performed by using 2D images only (typically requiring the measurement of 3D distances), we developed 3D inspection methods based on the analysis of 3D point clouds. For the 3D inspection of electrical cables, we proposed an original method for segmenting a cable within a point cloud. We have also tackled the problem of automatic selection of best view point, which allows the inspection sensor to be placed in an optimal observation position. The developed methods have been validated on many industrial cases. Some of the inspection algorithms developed during this thesis have been integrated into the DIOTA Inspect© software and are used daily by DIOTA's customers to perform inspections on industrial sites
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Sarfraz, Hassan. "Kinematics and Optimal Control of a Mobile Parallel Robot for Inspection of Pipe-like Environments." Thèse, Université d'Ottawa / University of Ottawa, 2014. http://hdl.handle.net/10393/30486.
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The objective of this thesis is to analyze the kinematics of a mobile parallel robot with contribution that pertain to the singularity analysis, the optimization of geometric parameters and the optimal control to avoid singularities when navigating across singular
geometric configurations. The analysis of the workspace and singularities is performed in a prescribed reference workspace regions using discretization method. Serial and parallel singularities are analytically analyzed and all possible singular configurations are presented. Kinematic conditioning index is used to determine the robot’s proximity to a singular configuration. A method for the determination of a continuous and singularity-free workspace is detailed.
The geometric parameters of the system are optimized in various types of pipe-like
structures with respect to a suitable singularity index, in order to avoid singularities during the navigation across elbows. The optimization problem is formulated with an objective to maximize the reachable workspace and minimize the singularities. The objective function is also subjected to constraints such as collision avoidance, singularity avoidance, workspace continuity and contact constraints imposed between the boundaries and the wheels of the robot. A parametric variation method is used as a technique to optimize the design parameters. The optimal design parameters found are normalized
with respect to the width of the pipe-like structures and therefore the results are
generalized to be used in the development phase of the robot.
An optimal control to generate singularity-free trajectories when the robotic device has to cross a geometric singularity in a sharp 90◦ elbow is proposed. Such geometric singularity inherently leads to singularities in the Jacobian of the system, and therefore a modified device with augmented number of degrees of freedom is introduced to be able to generate non-singular trajectories.
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Vissiere, Alain. "Mesure de cylindricité de très haute exactitude.Développement d’une nouvelle machine de référence." Thesis, Paris, ENSAM, 2013. http://www.theses.fr/2013ENAM0067/document.
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Le Laboratoire Commun de Métrologie LNE-CNAM (LCM) souhaite affiner sa maîtrise des références de pression afin de réaliser des appareillages de tout premier rang au niveau international. L'incertitude relative visée sur les références de pression est de l'ordre de 10-6. Cet objectif se traduit par une problématique de métrologie dimensionnelle où une mesure de la forme des pistons/cylindres utilisés dans les balances manométriques doit être menée. La mesure de cylindricité est également impliquée dans un très grand nombre d'applications industrielles comme la qualification d'étalons de référence destinés à la qualification d'appareillages de mesure. Notre travail de recherche, réalisé dans le cadre d'une convention CIFRE avec la SAS GEOMNIA, concerne la réalisation d'un instrument de référence de très haute précision permettant la mesure de forme de cylindres creux ou pleins. Nous proposons un saut technologique pour satisfaire un niveau d'incertitude sur la mesure de l'écart de cylindricité de l'ordre de 10 nanomètres dans un volume de mesure cylindrique de Ø350 mm et de hauteur 150 mm. La mesure de forme est habituellement pratiquée en déplaçant un capteur par rapport à la surface à mesurer par un guidage de haute précision. Il n'est cependant pas possible de réaliser un guidage entre deux solides d'un niveau de précision permettant de garantir les incertitudes souhaitées, même en utilisant les techniques de correction d'erreurs dont la précision est limitée par le défaut de répétabilité des guidages. Pour satisfaire à ce niveau d'incertitude, nous proposons une démarche basée sur le concept de structure métrologique dissociée. La mesure d'une pièce consiste alors à comparer sa forme à celle d'une pièce cylindrique de référence. Cette dernière doit seulement présenter une stabilité de forme parfaite. La cartographie d'écart de forme de la référence cylindrique doit cependant être identifiée au même niveau d'incertitude visé.Le travail de recherche développé propose une analyse détaillée des machines actuelles et de leurs limitations. Suite à cette analyse, une architecture de machine a été proposée pour lever ces limitations. Cette architecture tient compte des écarts « secondaires » liés à la position des capteurs et des effets de second ordre, pour satisfaire le niveau de précision visé. Une procédure complète d'étalonnage de la machine a été élaborée en s'inspirant des méthodes de séparation d'erreurs. Cette procédure originale permet de séparer les défauts de forme du cylindre de référence de ceux d'une pièce de qualification cylindrique mesurée simultanément. La méthode employée ne présente pas de limitations en termes d'exactitude. Cette procédure a été expérimentalement validée. Une analyse des effets liés à la mesure de surfaces cylindriques par des capteurs capacitifs a été menée. Ces essais ont conduit au développement de stratégies d'étalonnage de ces capteurs in situ utilisant des interféromètres à laser intégrés dans la machine. La traçabilité métrologique des résultats des mesures est ainsi garantie. Deux bancs de tests ont été développés pour caractériser les diverses influences et valider les procédures d'étalonnage des capteurs. La conception détaillée de l'instrument est issue de la synthèse des réflexions menées sur l'architecture, sur l'étalonnage et sur la maîtrise de la mesure de déplacements par capteurs capacitifs. Ce travail a abouti à la réalisation de ce nouvel instrument de référence ; sa conception, son montage et son réglage sont présentésThe “Laboratoire Commun de Métrologie LNE-CNAM (LCM)” seeks to improve the measurement of primary pressure standards done using pressure balances, to an order of 10-6 relative uncertainty. Therefore, it is appropriate to back-up these pressure balances with a measurement of the topology of the piston-cylinder devices used on these balances. Cylindricity measurement is also found in many industrial applications such as the measurement of standards used for the calibration of measuring machines. This research project, conducted in collaboration with SAS GEOMNIA under a CIFRE agreement, has a main objet to develop a new ultra-high precision machine for cylinders form measurement. We pushes with this project the leading edge of the cylinders form measurement area; we propose indeed a technological leap which leads to reduce the uncertainty associated to cylindricity errors up to 10 nm in a cylindrical working volume of 350 mm diameter rand 150 mm height. Form measurement is usually done using a measurement probe moved about the surface to be measured with high precision guiding systems. Nonetheless, these guiding systems are not precise enough to offer the low uncertainty required even when error correction techniques are used. This is because the precision of the guides is limited by their low repeatability. To meet this uncertainty level, we propose an approach based on the “dissociated metrological structure” concept. The measurement consists of comparing the artifact's form with the form of a cylindrical reference which should have perfect form stability. However, the mapping form deviation of this cylindrical reference needs to be identified at the same level of uncertainty referred.The present work exposes a detailed analysis of the existing measuring machines and their limitations. Consequently, an optimized machine architecture is proposed in order to overcome the present limitations. The proposed machine architecture takes into account the "secondary" error terms relative to the probes positions and second order effects in order to satisfy the level of accuracy sought. A complete calibration procedure of the machine has been elaborated based on the error separation methods; it allows the separation of the form errors of each of the reference cylinder and a qualification cylindrical part simultaneously measured. This procedure does not present any accuracy limitations and has been experimentally verified. An analysis of the effects related to the measurement of cylindrical artifacts using capacitive sensors has also been investigated. These experiments have led to the development of in-situ calibration strategies using laser interferometers integrated in the machine. Thus, the metrological traceability of the measurements is guaranteed. Two test benches have been developed to characterize the error sources that influence the measurement and to validate the calibration procedures of the probes used. The detailed design of the instrument synthesizes all the conceptual thoughts about the architecture, the calibration and the displacement measurement of the capacitive probes. This work has resulted in the development of this new reference instrument; its design, installation and adjustment are detailed
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Su, Rong. "Improved inspection and micrometrology of embedded structures in multi-layered ceramics : Development of optical coherence tomographic methods and tools." Doctoral thesis, KTH, Mätteknik och optik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-144595.
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Roll-to-roll manufacturing of micro components based on advanced printing, structuring and lamination of ceramic tapes is rapidly progressing. This large-scale and cost-effective manufacturing process of ceramic micro devices is however prone to hide defects within the visually opaque tape stacks. To achieve a sustainable manufacturing with zero defects in the future, there is an urgent need for reliable inspection systems. The systems to be developed have to perform high-resolution in-process quality control at high speed. Optical coherence tomography (OCT) is a promising technology for detailed in-depth inspection and metrology. Combined with infrared screening of larger areas it can solve the inspection demands in the roll-to-roll ceramic tape processes. In this thesis state-of-art commercial and laboratory OCT systems, operating at the central wavelength of 1.3 µm and 1.7 µm respectively, are evaluated for detecting microchannels, metal prints, defects and delaminations embedded in alumina and zirconia ceramic layers at hundreds of micrometers beneath surfaces. The effect of surface roughness induced scattering and scattering by pores on the probing radiation, is analyzed by experimentally captured and theoretically simulated OCT images of the ceramic samples, while varying surface roughnesses and operating wavelengths. By extending the Monte Carlo simulations of the OCT response to the mid-infrared the optimal operating wavelength is found to be 4 µm for alumina and 2 µm for zirconia. At these wavelengths we predict a sufficient probing depth of about 1 mm and we demonstrate and discuss the effect of rough surfaces on the detectability of embedded boundaries. For high-precision measurement a new and automated 3D image processing algorithm for analysis of volumetric OCT data is developed. We show its capability by measuring the geometric dimensions of embedded structures in ceramic layers, extracting features with irregular shapes and detecting geometric deformations. The method demonstrates its suitability for industrial applications by rapid inspection of manufactured samples with high accuracy and robustness. The new inspection methods we demonstrate are finally analyzed in the context of measurement uncertainty, both in the axial and lateral cases, and reveal that scattering in the sample indeed affects the lateral measurement uncertainty. Two types of image artefacts are found to be present in OCT images due to multiple reflections between neighboring boundaries and inhomogeneity of refractive index. A wavefront aberration is found in the OCT system with a scanning scheme of two galvo mirrors, and it can be corrected using our image processing algorithm.QC 20140428
Multilayer (FP7-NMP4-2007-214122)
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Benmoussat, Mohammed Seghir. "Hyperspectral imagery algorithms for the processing of multimodal data : application for metal surface inspection in an industrial context by means of multispectral imagery, infrared thermography and stripe projection techniques." Thesis, Aix-Marseille, 2013. http://www.theses.fr/2013AIXM4347/document.
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Le travail présenté dans cette thèse porte sur l'inspection de surfaces métalliques industrielles. Nous proposons de généraliser des méthodes de l'imagerie hyperspectrale à des données multimodales comme des images optiques multi-canales, et des images thermographiques multi-temporelles. Dans la première application, les cubes de données sont construits à partir d'images multi-composantes pour détecter des défauts de surface. Les meilleures performances sont obtenues avec les éclairages multi-longueurs d'ondes dans le visible et le proche IR, et la détection du défaut en utilisant l'angle spectral, avec le spectre moyen comme référence. La deuxième application concerne l'utilisation de l'imagerie thermique pour l'inspection de pièces métalliques nucléaires afin de détecter des défauts de surface et sub-surface. Une approche 1D est proposée, basée sur l'utilisation du kurtosis pour sélectionner la composante principale parmi les premières obtenues après réduction des données avec l’ACP. La méthode proposée donne de bonnes performances avec des données non-bruitées et homogènes, cependant la SVD avec les algorithmes de détection d'anomalies est très robuste aux perturbations. Finalement, une approche, basée sur les techniques d'analyse de franges et la lumière structurée est présentée, dans le but d'inspecter des surfaces métalliques à forme libre. Après avoir déterminé les paramètres décrivant les modèles de franges sinusoïdaux, l'approche proposée consiste à projeter une liste de motifs déphasés et à calculer l'image de phase des motifs enregistrés. La localisation des défauts est basée sur la détection et l'analyse des franges dans les images de phaseThe work presented in this thesis deals with the quality control and inspection of industrial metallic surfaces. The purpose is the generalization and application of hyperspectral imagery methods for multimodal data such as multi-channel optical images and multi-temporal thermographic images. In the first application, data cubes are built from multi-component images to detect surface defects within flat metallic parts. The best performances are obtained with multi-wavelength illuminations in the visible and near infrared ranges, and detection using spectral angle mapper with mean spectrum as a reference. The second application turns on the use of thermography imaging for the inspection of nuclear metal components to detect surface and subsurface defects. A 1D approach is proposed based on using the kurtosis to select 1 principal component (PC) from the first PCs obtained after reducing the original data cube with the principal component analysis (PCA) algorithm. The proposed PCA-1PC method gives good performances with non-noisy and homogeneous data, and SVD with anomaly detection algorithms gives the most consistent results and is quite robust to perturbations such as inhomogeneous background. Finally, an approach based on fringe analysis and structured light techniques in case of deflectometric recordings is presented for the inspection of free-form metal surfaces. After determining the parameters describing the sinusoidal stripe patterns, the proposed approach consists in projecting a list of phase-shifted patterns and calculating the corresponding phase-images. Defect location is based on detecting and analyzing the stripes within the phase-images
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CRO, PAOLO. "Gestione del rapporto di lavoro e intervento pubblico nel sistema giuslavoristico." Doctoral thesis, Università Cattolica del Sacro Cuore, 2007. http://hdl.handle.net/10280/95.
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L'opera esamina l'intervento pubblico nella gestione del rapporto di lavoro sotto il profilo storico e giuridico nelle tre fasi d'instaurazione, gestione e cessazione del rapporto. Si valorizza anche il ruolo specifico dei tre poteri legislativo, esecutivo e giudiziario, con particolare riguardo all'analisi sistematica del diritto amministrativo del lavoro. L'opera intende porre in luce gli elementi logici, giuridici ed assiologici di questo ramo del diritto del lavoro, per ricondurne le fattispecie esaminate ad un sistema coerente e razionale e per suggerirne sia un metodo d'analisi de iure condito sia una prospettiva per una lettura ed una proposta de iure condendo.This work analyses how public powers affects labour relationships both from the historical and the juridical points of view. The three main phases of labour relationships beginning, management and end are examined separately. The specific contributions by the three public powers legislative, administrative and judiciary especially by the public administration, are also dealt with. The goal is to illustrate the logical, juridical and ethical elements of this branch of the labour law, in order to build a rational system for both the analysis de iure condito and the debate de iure condendo.
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Lan, Zi-Yue, and 籃子越. "Machine Vision 2 Dimensions and 3 Dimensions detection for semiconductor coating inspection." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/s6re72.
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碩士國立高雄科技大學
機械工程系
107
This study is applied to semiconductor components and ceramic substrates by 2D and 3D machine vision inspection systems. In the past, the semiconductor machine inspection system used 2D for testing, but the technology is changing with each passing day, and many components are extremely precise. Therefore, it is necessary to detect 3D in more detail and carefully, so as to avoid unawareness. In this experiment, we use 2D image binarization and 3D smart sensor as a tool for measurement and detection. 3D laser sensor can detect moving targets with resolution up to 1.5μm and sampling rate up to 35 kHz. The 3D point cloud map can be generated in one time and can be applied to the robot. 2D vision can not detect the 3D geometry of an object, and 3D detection can provide spatial geometry data related to the shape of the object. Whether it is printed circuit board (PCB) on-line inspection or ceramic substrate packaging can be used for surface measurement of complex measurements. The use of 3D inspection can greatly increase the yield by discussing its mechanical properties and reliability. The 2D test results and 3D measurement data are used as supporting evidence. Keywords: 3D, Mechanical vision, inspection Sensor, Printed circuit, board Ceramic substrate, Point cloud
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Hodgson, Sally. "A Study of the impact of British Columbia’s meat inspection regulations and amendment on food security in select rural and remote communities in BC." Thesis, 2012. http://hdl.handle.net/1828/4273.
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Food safety regulations have increased over the past decade in response to food safety scares, international trade and changing public demands. The purpose of this thesis is to determine the impacts of meat safety regulations and a subsequent amendment on food security in rural and remote communities in British Columbia. Case studies of three communities, Bella Coola Valley, Haida Gwaii and Powell River Regional District, were utilized to assess these impacts. Interviews with government officials and local farmers were combined with agricultural and socio-economic data. Though it is not possible to attribute impacts directly and solely to the change in regulatory structure, it appears that the addition of harsh safety regulations has damaged an already fragile local meat industry in these vulnerable communities. The regulation amendment solved some of these issues, but many rural regions are still struggling to maintain local self-sufficiency in food production.Graduate
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Abou, Shaar Belal. "Adaptable Three Dimensional System for Building Inspection Management." Thesis, 2012. http://hdl.handle.net/10012/6923.
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Sustaining the safety and operability of civil infrastructure assets, including buildings, is a complex undertaking that requires a perpetual cycle involving inspection, and further decisions for renewal fund allocation. However, inspection, which is the basis for all subsequent decisions, is a complex task to manage, particularly when a large number of assets are involved. The current lack of a structured process with visual referencing as well as the high subjectivity and inflexibility to changing inspection requirements make current inspections very costly and time consuming.
This research improves the building inspection process by introducing a 3D system for inspection management that has four unique features: (1) a structured assessment approach that considers multiple organizations, buildings and inspectors, using a GIS interface; (2) a 3D visual referencing method for marking problem areas during inspections to facilitate all on-site inspections, thus reducing time and cost; (3) a visual guidance module to reduce inspection subjectivity; and (4) a flexible module for designing different assessment types. The proposed inspection management system creates 3D building plans from 2D Computer-Aided Drawing (CAD) to provide location referencing that enhances inspection effectiveness. The visual guidance system allows inspectors with various experience levels to perform consistent inspections and requires less training, thus reducing costs. Flexible inspection generation also allows a variety of inspection types, such as condition and level of service, to be readily incorporated.
A computerized prototype system has been developed using the Windows Presentation Foundation’s XAML markup language with underlying C# programming on a tablet computer for experimentation. The thesis provides a detailed description of system development and reports the benefits of the system on a sample inspection. Accordingly, the system has proven most useful for large organizations that own a large number of building assets that require frequent inspections.
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Huang, Guo-Long, and 黃國龍. "Automatic Image Inspection System for Workpiece Dimension." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/22716349275497385023.
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碩士國立雲林科技大學
機械工程系碩士班
101
This study applies automated vision inspection system for measuring and inspecting workpiece dimension. In this study, sliding track and knife saddle rail are used as sample object for system development. The system is written in C++, using OpenCV library for image processing, and Qt library for graphical user interface. Hardware used are as the following: a CCD camera, transparent acrylic fixture, and a backlight, fixed on a metal stand. Object to be processed is first fixed on the trasparent fixture with backlight, then the image of the particular object is taken to be processed. The process of the system can be divided into two groups: creating the template, and workpiece inspection. To create a template, an image of standard workpiece has to be taken, and user has to define image processing parameters, find features rule definite standard. The template is then image processed, getting features by find features rule. Features retrieved is then used to determine object dimension. The same process and parameter is applied to workpiece inspection, finding corresponding features. Finally sizes is computing and compared tolerance, thus determining if the workpiece inspected is up to standard.
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Ferguson, Bradley S. "Three dimensional T-ray inspection systems." 2004. http://hdl.handle.net/2440/37962.
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Pulsed terahertz (THz) systems are an emergent technology, finding diverse applications as they approach maturity. From their birth in the late 1980's to the wealth of alternate sources and imaging modalities now available, the rise has been fuelled by the expectation that this will prove a world changing technology. This Thesis takes an application focused approach and seeks to provide enabling systems and algorithms for the development of functional imaging systems with broad potential application in security inspection, non-destructive testing and biomedical imaging. Three dimensional pulsed THz imaging systems were first introduced in 1996 using a reflection-mode ultrasound-like configuration. This Thesis builds upon this former work by focusing on transmission mode tomography systems using pulsed THz radiation. Several novel 3D imaging modalities are introduced. The hardware architectures, based on optoelectronic generation and detection of THz radiation are described. Approximations to the wave equation are derived, allowing linear reconstruction algorithms to recover 3D structural information fromthe transmitted THz field. Finally the systems are demonstrated and the achievable resolution and image quality are investigated. Three imaging architectures are developed herein: 1. T-ray holography allows the 3D distribution of point scatters to be resolved based on a single projection image utilising a novel reconstruction algorithm based on the windowed Fourier transform and back-propagation of the Fresnel-Kirchhoff diffraction equation. 2. T-ray diffraction tomography utilises the diffracted THz field to allow a Helmholtz equation based, frequency-dependent reconstruction to be performed and the THz spectrum at each pixel to be calculated. 3. T-ray Computed Tomography (CT) uses analogous techniques to X-ray CT, based on the Radon transform, to provide 3D T-ray reconstructions of unprecedented fidelity. These techniques have important applications in material identification, which is investigated in the second part of this Thesis. Pulsed THz spectroscopy has been widely acclaimed for its potential to identify different materials based on their spectral properties. The second part of this Thesis presents algorithms towards this goal. Three case studies are performed focusing on biomaterial classification, anthrax detection and in vitro osteosarcoma cell differentiation. A classification framework is developed to process the THz spectral data and identify specific materials. A linear filter model is introduced to describe the system response of different materials, and the filter taps are utilised for feature extraction. This technique is demonstrated for biomaterial and anthrax classification. For cell differentiation a genetic algorithm is used to select deconvolved frequency components to train a classifier. In each case a high classification accuracy is demonstrated, highlighting the promise and potential of three dimensional T-ray inspection systems.Thesis (Ph.D.)--School of Electrical and Electronic Engineering, 2004.
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Zheng-Wei, Wang, and 王政暐. "Development of Dimension Inspection System for Carrier Tape." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/18358862355550443244.
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碩士遠東技術學院
機械研究所
93
In this paper, image processing is applied to build up a dimension inspection system for carrier-tape. A fast and simple technique is used for dimensional inspection of the carrier type. In order to improve the holes detection from the original image, two auxiliary light sources are used to improve the contrast between holes and edges. An improvement on Otsu’s threshold method is designed for a more effective computation of a threshold value, which separates the object from the background. Hardware and software are both used in a coordinated manner to find an optimal threshold value and to simplify the image processing procedures. Canny edge search method is used to find the object edge. For the holes measurements, this method randomly finds four right triangles from the four quadrants in a circle, and then computes the circle diameter using the Pythagorean theorem. This paper proposed a simple and effective method to replace the complicated algorithms by using two threshold values and two auxiliary light sources to make the dimensional inspection system more stable. The method, which needs to acquire the image, processes the image, and measures the carrier-tape dimension completes in approximately 1.2 seconds. The accuracy of the inspection method is approximately 0.02mm, which is sufficient to meet the demands of carrier-type dimensional inspection.
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汪德美. "Applying Corner Detection Method in Dimensional Inspection." Thesis, 1991. http://ndltd.ncl.edu.tw/handle/28940436487397112216.
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碩士國立清華大學
工業工程研究所
79
This thesis includes four parts: First, a contour tracking method is introduced in order to obtain a sequence of integer-coordinate edge points. This is the preliminary task for corner detection. Secondly, a simple algorithm for corner detection is proposed. The method applies the concept of cancellation of the vector''s direction on both side (the forward and backward arms) of a point to detect corners. Comparing the results with that of the other corner detectors, the similar results are obtained. Our method is simpler in the computation of discontinuity. Thirdly, camera calibration proposed by Chang was introduced. The method involves two types of transformation: homogeneous and quadratic calibration. Besides, we develop a simple method to transform dimensions between the image plane and the real-world plane by using a transformation factor. Finally, two mechanical parts (i.e. screws and gears) are inspected by our comer detector. For external screws, we inspect three defects: the missing thread, the distorted thread and the thread without axial symmetry. For gears, we measure the pitch variance and the total accumulated pitch variance.
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Hsu, Sheng-Jie, and 許勝傑. "Miniaturized Three-Dimensional Optical Inspection System for Industry 4.0." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/8rsyru.
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碩士中原大學
奈米科技碩士學位學程
106
“Industry 4.0,” or the fourth industrial revolution, is a high-tech plan proposed by Germany. With advantages of penetrative scanning and adequate resolution, Optical Coherence Tomography (OCT) is one of the promising industrial imaging technologies that can be used for nondestructive inspection of factory products. At present, most of the imaging facilities in the market yield 2D images, and therefore are challenging in quick 3D imaging of the samples like touch panels of mobile phones or panel substrates of solar cells. At present, the optical inspection machines in the market are commonly large in size, heavy in weight, and high in price. Besides, the requirement of manual operation results in high detection error rate and its increasing with time, which not only reduces the efficiency but also increases the production costs. This paper established miniaturized OCT module for observation of the internal structure of the mobile touch panels and solar cell panels. We employed 5mm microlenses and 2cm micro-actuators to construct the module and made the entire optical inspection system reduced to 5 to 10cm in length. It can then be applied to an automatic optical inspection array with even higher scan speed and throughput. The defected mobile phone panels or solar cell panels can be directly discarded without subsequent processing cost, and the information can be fed back for parameters optimization of the production line. The rapid development of Industry 4.0 makes high-speed inspection more valuable. Optical tomography technique can be applied to construct a quality-control system that performs automated on-line scans, prompt three-dimensional inspection, and real-time feedback for fine tuning of production parameters to establish a fully-automated factory environment. Due to its non-invasive ness and small volume, the “Miniaturized 3D Optical Inspection System for Industry 4.0” has great market potential in panel detection, automation system, and other related industrial fields.
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Hsieh, Yuan-Ming, and 謝元銘. "Development and Application of Three Dimension Ball Grid Array Inspection System." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/04256021989772960837.
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碩士國立臺灣大學
機械工程學研究所
91
The aim of this study is to construct a prototype of Precision 3D Measurement System for the Dimensional Inspection of BGA Components, which could be integrated into the process of BGA packaging. This system focus on the 3D inspection on Coplanarity, Ball height and Board Warpage. I used Triangular Method of Structure Light as the main principle of this thesis. Therefore, the micro focus linear laser is adopted to project a single light fringe on the BGA. Then, we used a CCD Camera to capture the images of the curve of the fringe projected on BGA. After a set of image processing techniques, we may obtain the cross-section profile of BGA in the Image Coordinate, and then convert the site data of Image coordinate to Space Coordinate. By the work of an X-Y Stage, we can scan the BGA to get more cross-section profile at different site on the same BGA. That way, we get three dimension profile data of BGA. Besides, I bring up a solution of complex reflection phenomenon which happens in BGA measurement process. Finally, I use real-time calculating algorithm to obtain the result of BGA inspection on Coplanarity, Ball height and Board Warpage.
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Huang, Wen-Cheng, and 黃文成. "Developing the 2D Precision Inspection System on BGA IC Component Dimension." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/56356905579854730602.
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碩士國立屏東科技大學
機械工程系
88
The purposes of this study to develop a set of vision system to inspect 2D BGA dimension including ball size, position and quality and the distance from outside of inner ball to the side of package in BGA IC. In the system, we use the software of image processing (Matrox MIL5.0), the windows development tool (Microsoft Visual Basic5.0) and the conception of Machine Vision. The results indicate that the inspection time is 0.2 second per BGA IC(ball number 48,BGA Length：7mm,BGA width：7mm)，the measurement accuracy for ball position is less than 0.8mil , ball size for package dimension is less than 1 mil and the distance from edge ball to the sides of package is less than 1 mil and the repeatibility is ranging within 0.5mil.
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Shen, Ta-Cheng, and 沈大誠. "Multi-Layer Ceramic Capacitor Inspection Using One-Dimensional Wavelet Transform." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/01923207684518604145.
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碩士國立臺北科技大學
生產系統工程與管理研究所
91
This paper exploits a wavelet-based scheme to inspect the surface defects and basic dimensions of 0805 Multi-layer Ceramic Capacitors (MLCC) using machine vision. The image of passive component is initially processed to show only two solder plates (terminations). Then, the covariance matrix eigenvector for each boundary point generates the 1D θ-p representation to describe the angle variations at the boundaries of each termination. The 1D θ-p representation is further decomposed directly by one-dimensional wavelet transform (1D WT). Since a single corner (intersection of two boundary edges) and jag corners (surface defect) are local deviations on termination boundaries, their locations are represented as intensive and highly fluctuated wavelet energy at the 1st detail scale. Concerning 0805 MLCC type of passive component, the surface defects and single corners on termination boundaries can be captured by appropriate thresholds (e.g. in wavelet energy). The basic dimensions of a passive component are simply the direct distance between located single corners. Real 0805 MLCCs are testing samples to evaluate the performance of the proposed approach. Experimental results show that the proposed method achieves precise identification for surface defects and measurement for basic dimensions. The proposed approach is invariant with respect to the orientation, easy to implement, and free from primitive-matching process. Therefore, it is especially suitable for various types of passive component that are similar to 0805 MLCC in small-batch production.
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CHANG, FU-KAI, and 張復凱. "Dimension and defect inspection Module for self-lubricating bearings by Machine vision." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/5bv8dm.
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碩士國立雲林科技大學
機械工程系
106
Currently, the self-lubricating bearings have been inspected by manual operation. With the development of industry and the advance of productive technology, demands on inspection cannot be achieved by conventional procedure. Since the efficiency of manual detection is much lower than the productive efficiency and the examination standard of inspectors would be effected by fatigue, the inspected results performed by each operator are different. From the above mentioned descriptions, the conventional inspection is replaced by the automatic optical inspection. The major issue of this study is based on the measurement theories and defect detection method of bearing. The constructed module for the detection of dimension and defect which contains measurement principle, image process and definitions of defect parameter has been developed with machine vision. In this investigation, the precision of measurement system is analyzed by the repeatability experiments. To verify the accuracy of the proposed system, a vertical projector for self-lubricating bearing will be utilized as reference standard for comparison measurement and defect detection between projector and the developed module. According to the experiment results, the standard deviation of the proposed measurement system is about 0.023mm. The maximum deviation between this system and reference system is 0.015mm. The rate of defect product inspection is 100% and normal products have 2.28% overkill. the speed of inspection increase from 87pcs/min to 250 pcs/min. The rate of inspection speed increase 181%.
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Hsu, Hui-Chung, and 許惠中. "3-Dimensional Defect Inspection of Workpieces Profile by Digital Image Processing." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/nf7zv7.
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Wang, Jia-Yan, and 王家彥. "Automatic image inspection module for dimensional measurements of the rubber plies." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/93582887972557388162.
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碩士國立雲林科技大學
機械工程系
102
Tires play an important role in driving safety. The tread rubber is on the outermost layer of the tire; its main function is protecting the carcass when the car is driving. Because it’s directly contacting the road it’s the tire’s part with the biggest abrasion. The tread rubber can provide tire traction in a wide range of use and it can resist puncture, abrasion and heat. Therefore, the most important thing about a tire is the accuracy of its rubber dimensions. This research’s investigations focus on automatic measurement technology using line lasers and a CCD camera. Considering that in online processing only total width detection used to be applied, there was no real-time detection process for measuring the top width of the tread rubber. Therefore, operators used to cut out a small part of rubber to be measured after the end of the process, unable to reach a comprehensive online detection. Due to this reason two automatic systems for dimensional measurements of tread rubbers have been developed, of which one being an off-line and one being an on-line system. Both systems use image processing software, a CCD camera, three line lasers attached to fine tuning seats and a red filter to measure both the total width and the top width of the tread rubber. Different light sources to the line laser have been proven of causing major problems due to the variance in reflectivity of different rubber materials. In order to verify the measurement capability of the system, its repeatability has been analyzed by using the commercial profile measurement system Tri-Scan. Whilst the off-line measurement system showed a maximum standard deviation of 0.11 mm the largest standard deviation when using the on-line system was 0.3 mm. These deviations are smaller than ±0.5 mm. Therefore, the on-line system should meet the requirements of tire abrasion measurements.
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Li, Chun-I., and 李俊逸. "Detect the Two-dimensional defect of solder balls by automatic optical inspection." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/38977906013542544764.
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碩士聖約翰科技大學
電子工程系碩士班
96
ABSTRACT Ball-Grid-Array (BGA) has become one of the most popular packaging techniques in the electronic industry. This study proposed an automatic optical inspection (AOI) system for two-dimensional (2D) defects of BGA solder balls. The proposed system captures 2D gray-level image of solder balls by CCD camera, collocating with a proper lighting, and then extracts the image features of the inspected solder balls with thresholding, edge detection, blob analysis, image projection, roundness measurement and pixel-area method. Experiments have shown that the 2D defect inspection of the BGA solder ball defects such as absent ball, deformed ball, double ball, ball offset, oversized ball and undersized ball is very efficient and effective with the proposed AOI system. The processing time of the proposed system for an image of 640×480 pixels is less than 0.2 second on a typical personal computer. Keywords: Automatic optical inspection; Two-dimensional inspection; Solder-ball defects
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Ou, Tao-chi, and 歐陽燾騏. "Two-Dimensional Bar Code Inspection of TFT Array for LCD Manufacturing Process." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/61213627055645394785.
Full textAbstract:
碩士逢甲大學
資訊電機工程碩士在職專班
100
LCD products are part of smart phones, LED TVs and computers that are full with our daily lives. Some manufacturers adopt the barcode in quality control under the production process of LCD glass substrate. The quality control in the production process and output are 100% inspected. Traditional visual inspection by operators is time consuming and subject to human errors as of fatigue. Our research establishes an inspecting system of data matrix of barcode to replace with traditional inspection. The system is one that extracts non-contact optical inspecting method. QR image printed on LCD metal layer and non-metal layer is taken by combination of CCD camera and image processing software. The inspection highlights include the readability, correction and deviation of data matrix barcode. The software has advantages such as convenience and flexibility, and the user can check the results directly in friendly man-machine interface. Data from CCD camera can be output to SVMS software for quality analysis. The object of experiment is to increase the production rate and quality of manufacturing and simultaneously lower the cost by automatic inspecting of machine vision. The CCD camera is saturated in the situation higher than 850nm wavelength light while in taking barcode. We can improve the quality of data matrix barcode inspecting with an attachment filter to filter out the wavelength light with higher than 850nm.
48
FA-HSUAN, CHU, and 朱法軒. "Development of an Optical Inspection System Used for Measuring Dimension of Bonded Microfluidic Chips." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/6wuvc6.
Full textAbstract:
碩士國立臺灣科技大學
機械工程系
106
This study aims to develop an automated optical inspection system for measuring microchannel dimension. Research about microfluidic chip has flourished in recent years. There will be more and more related products which are important for dimension appearing. Therefore we developed a non-destructive and non-contact measurement for bonded microfluidic chip to verify whether the microchannel dimension meets the tolerance specification. The data measured with measurement system we’ve developed is compared with the reference value measured with toolmaker microscope. The error obtained after comparing reaches ± 2 %.
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Huang, Go-Li, and 黃國豊. "Development of an Inspection System for the Appearance Dimension of Multi-Layer Ceramic Capacitor." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/19839885773088815392.
Full textAbstract:
碩士國立屏東科技大學
機械工程系所
95
The study of the research is to develop a low-cost, easy to operate, rapid, precision automatic system of measuring the MLCC’s (Multi-Layer Ceramic Capacitor) apparent dimension. Through the oscillation feeding mechanism, The MLCC is discharged to the patt of realignment mechanism and conveyed to the rotational plate in the same direction; the mechanical vision technology is used on the plate to measure the MLCC’s apparent dimension. It finalizes the low-cost, stable,rapid system of sensing the apparent dimension. That we use the technology of cooperatively processing the fetching image motion and the image calculation and combine the optical imaging technology and the self-developed lighting module. The design of this dissertation is to use the to quickly discharge MLCC to the weight-bearing plate, turn the plate to the localization sensor, through the memory localization of the ensor convey MLCC to the measuring station and use the memory localization and the digital image technology to fast measure the MLCC’s apparent dimension. The equipment now can measure the MLCC’s apparent dimension. At length, through the practical measuring experiment we assess the system’s speed and power of measuring. It is expected to accomplish over 200 MLCCs each minute. The system’s reappearing can reach GR&R 9.98％ and the accuracy reaches 0.04mm, which can fulfill the industry’s requirements, promote the measuring accuracy and reduce the time and human resources.
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TSAI, YUAN-ZHANG, and 蔡沅璋. "Development of Inspection System for Dimensional Measurements of Grinding Wheels by Image Processing." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/8a5454.
Full textAbstract:
碩士國立虎尾科技大學
機械與電腦輔助工程系碩士班
107
The machine vision technology is mainly applied to dimension measurement, defect inspection, etc. In the past, traditional manual measurements were not only inefficient, but they were often subject to different operations or judgments by the inspectors. These causes resulted in different measuring results. In order to improve these problems, the industry is now moving toward automatic measurements. The machine vision and vision inspection have also been widely used in the industry, which can improve efficiency, reduce human visual errors, and improve the reliability of measurements. The main purpose of this thesis is to employ Borland C++ Builder to develop an automatic image inspection system with the PC-based controller and X, Y, Z, and C four-axis platform mechanism for measuring the geometry of the grinding wheels. The coordinate position can be obtained from the operation screen of the controller and the image inspection system. The Sobel operator is adopted to calculate the gradient value to implement the autofocus and automatic measurements. The guidance pictures of the human machine interface lead the operators to achieve user-friendly and simple measurements of the grinding wheels. In this study, the TG-5 tool grinder is applied to grind the round bars to verify the error between the verification result and the expected result. The errors of the outside diameter of the grinding wheel and the flange distance are both 6 μm. Experimental results show that the radius measurement error is within 1.96 % in comparison with the five-axis measuring machine Zoller genius 3. This means that the measurement accuracy of the proposed inspection system is within a reasonable range.