Wilson D.,ITER Organization |
Bernard N.,G2Metric |
Mariani A.,Spatial Alignment Ltd.
Fusion Engineering and Design | Year: 2015
The assembly of ITER will involve the precise and accurate alignment of a large number of components and assemblies in areas where access will often be severely constrained and where process efficiency will be critical. One such area is the inside of the vacuum vessel where several thousand components shall be custom machined to provide the alignment references for in-vessel systems. The paper gives an overview of the process that will be employed; to survey the interfaces for approximately 3500 components then define and execute the customization process. © 2015 ITER Organization.
Zhu T.,University of South Carolina |
Sutton M.A.,University of South Carolina |
Li N.,University of South Carolina |
Orteu J.-J.,CNRS Clement Ader Institute |
And 3 more authors.
Experimental Mechanics | Year: 2011
Accurate, 3D full-field measurements at the micron-level are of interest in a wide range of applications, including both facilitation of mechanical experiments at reduced length scales and accurate profiling of specimen surfaces. Scanning electron microscope systems (SEMs) are a natural platform for acquiring high magnification images for stereo-reconstruction. In this work, an integrated methodology for accurate three-dimensional metric reconstruction and deformation measurements using single column SEM imaging systems is described. In these studies, the specimen stage is rotated in order to obtain stereo views of the specimen as it undergoes mechanical or thermal loading. Simulations and preliminary experimental studies at 300× demonstrate that (a) spatially-varying image distortions can be removed from images using a non-parametric distortion model, (b) the system can be reliably calibrated using distortion-corrected images of a planar object and grid at various orientations and (c) specimen rotation variability during the measurement phase can be controlled so that baseline strain errors are within the range of ±150 με. Benchmark rigid body motion experiments using calibrated SEM views demonstrate that all components of strain in the reconstructed object have a mean value around O(10-4) and a random spatial distribution with standard deviation ≈ 300 micro-strain. © 2010 Society for Experimental Mechanics.
Viana I.,CNRS Clement Ader Institute |
Bugarin F.,CNRS Clement Ader Institute |
Cornille N.,G2Metric |
Orteu J.-J.,CNRS Clement Ader Institute
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2015
This paper focuses on quality control of mechanical parts in aeronautical context by using a single PTZ camera and the CAD model of the mechanical part. In our approach two attributed graphs are matched using a similarity function. The similarity scores are injected in the edges of a bipartite graph. A best-match-search procedure in bipartite graph guarantees the uniqueness of the match solution. The method achieves excellent performance in tests with synthetic data, including missing elements, displaced elements, size changes, and combination of these cases. © 2015 SPIE.