IMEKO Event Proceedings

Page 4 of 748 Results 31 - 40 of 7479

Kazuhiro Enami, Tatuya Kume, Yasuo Higashi, Kenji Ueno
3D MEASUREMENT OF INNER SHAPE OF A CAVITIY

We strive to develop a 3D coordinate measuring machine, which can measure the inner shape of a cavity with a complex shape. Currently, the ILC (International Linear Collider) project is progressing through international collaboration. The major goal of ILC is to produce and investigate Higgs bosons. ILC consists of two linear accelerators facing each other, and will hurl some 10 billion electrons and positrons toward each other at nearly the speed of light. The cavity is an important component to accelerate particles to near light speed. A cavity’s inner 3D shape influences the accelerating performance. Therefore, it is important to measure the inner 3D shape of a cavity. However, it is difficult to measure the inner shape of cavities with complex shapes like a bellows. We are developing a highly accurate, inner shape measuring machine using triangulation and a measuring method.

Yuri Chugui, Sergei Plotnikov, Anatoly Potashnikov, Alexander Verkhogliad
3D MEASURING TECHNOLOGIES FOR INDUSTRIAL AND SCIENTIFIC APPLICATIONS

The novel results of the R & D activity of TDI SIE SB RAS in the field of the optical measuring technologies, as well as laser technologies for solving safety problems are presented. To measure the rocks stress and to prevent the mountain impact, as well as for basic investigations, a set of optical-electronic deformers and systems was developed and produced. For permanent noncontact bearing position inspection of oil-drilling platforms on Sakhalin coast (Russia) we have developed optical-electronic method and system SAKHALIN. Multifunctional laser technological system LSP-2000 equipped by two Nd-YAG lasers was developed for cutting, welding and surface micro profiling with ablation process (working range of 3 x 2 x 0.6 m³, positioning error less than 10 mkm). Results of development and testing the specialized high productive laser measuring machine, based on structured illumination, for 3D inspection of grid spacers for Russian nuclear reactors with micron resolution are presented. Using high-speed laser noncontact method on the base of triangulation position sensors, TDI SIE has developed and produced automatic laser diagnostic system COMPLEX for inspection of geometric parameters of wheel pairs (train speed up to 60 km/hr.), which is used successfully on Russian railways.

Efstratia Chatzi, Stamatis Chatzistamatis, Nikolaos Soulakellis, Nikolaos Zouros, Christos-Nikolaos Anagnostopoulos
3D Modelling of Petrified Trees: Laser Scanning vs Photogrammetry

In this paper, a methodology for the photogrammetric and laser scan survey of tree fossils of the Petrified Forest on Lesvos island in Greece, is proposed.The Petrified Forest is of particular interest since it is one of the rarest monuments of geological heritage worldwide and it was formed from the fossilized remains of plants. During this study, photogrammetric and laser scanning data by the tree fossils have been gathered, processed and modelled in 3D, and a comparison of the two techniques is taking place. Finally, the most suitable technique for the 3D modelling of objects such as the petrified trees is proposed.

Mauro Lo Brutto, Maria Grazia Spera
3D mosaics survey: analysis of photogrammetric/computer vision approach in a metrological context

The goal of the paper is evaluate photogrammetric/computer vision approach in a metrological context for 3D mosaics survey. The aim of the mosaics survey is the production of a full-scale representation (scale 1:1) useful for the documentation and for the restoration processes. In order to evaluate the optimal photogrammetric/computer vision workflow in this work three different surveys have been done for three mosaics with different size and location. Two of these are stored at Regional Archaeological Museum “Antonino Salinas” in Palermo (Italy) and the other one is stored at Regional Archaeological Museum “Baglio Anselmi” in Marsala (Italy). The research has allowed to show the potentiality and the issues of photogrammetric/computer vision approach for the 3D mosaic documentation.

S. N. Makarov, S. V. Plotnikov, E. V. Sysoev, A. G. Verkhogliad, P. S. Zav’yalov, Yu. V. Chugui, A. V. Latyshev, E. S. Senchenko
3D OPTICAL MEASURING TECHNOLOGIES FOR SCIENTIFIC AND INDUSTRIAL APPLICATIONS

Solving many actual safety problems in science, atomic, optics-mechanical and railway industry takes 3D optical measuring technologies with micro-/ nanometer resolution and productivity from 100 to 105 meas./s. The novel results of the R & D activity of TDI SIE SB RAS in this field are presented.

M. Mongelli, I. Bellagamba, G. Bracco, S. Migliori, A. Perozziello, S. Pierattini, A. Quintiliani, B. Mazzei
3D photogrammetric reconstruction by "Structure from Motion" as a monitoring technique for safety, conservation and improvement of the fruition of cultural heritage

In the last years, with the large growth of new state-of-the-art technologies used in the field of cultural heritage, it's increasingly necessary to promote non-invasive and non-destructive techniques which are "sensitive" to the nature of the site in which they are applied, respecting the Italian historical artistic heritage. Within the COBRA project [1], ENEA developed a new low-cost and non-destructive survey technique by 3D Photogrammetric reconstruction, using the Structure from Motion (SfM) method, for innovative applications in the field of cultural heritage [2]. This paper shows an application of this methodology on the archaeological complex of Priscilla's Catacombs in Rome. Three case studies have been identified, with several design purposes, showing the different applications of this technique: a sarcophagus called "Sarcofago delle Muse" , a chapel named "Cappella Greca" and a masonry element, which are all situated in the "Criptoportico" area.

De Giorgi L., Leucci G.
3D resistivity anomaly probability tomography at the archaeological site of Sagalassos (Turkey)

The archaeological site of Sagalassos is a very important settlement located in a magnificent mountain landscape, 7 km north from a little village named Aglasun (province of Burdur, SW Turkey). Since 1990 the University of Leuven (Belgium) carry out an interdisciplinary archaeological research programme that study the uninterrupted occupation of more than 1000 years in all its aspects from daily life to architecture, from trade and its mechanisms to environmental conditions of the past. The ancient roman city is a site covered under erosion layers and preserved many secrets that need to be revealed. A geophysical campaign was planned along the south facing terraces of the mountain slopes, in order to highlighting the structure of the city still covered. Site conditions (high slope, high grass, several obstacles) and the need to investigate high depths led to the choice of the most suitable geophysical methods. Particularly a 3D distribution in the subsoil of resistivity tensor probability was esteemed.

K. Tsujioka, H. Furuhashi, Y. Uchida
3D SHAPES MEASUREMENT SYSTEM USING AN OPTICAL MODULATOR

We have continued research on 3D shapes measurement system using spatial modulator. The advantages of this system are non-contact, non-invasive, and short time measurement. We proposed a method using differentiation to expand the measurable area and improve the accuracy of measurement. Additionally, We proposed to eliminate the influence of marking on target object surface. It was a very practical and effective method.

F. Bitte, H. Mischo, T. Pfeifer, G. Frankowski
3D SURFACE INSPECTION WITH A DMD BASED SENSOR

In this paper a method for non-contact scanning of small structures is presented similar to that of confocal microscopy but using the technology of Digital Micromirror Devices (DMD) instead of ordinary pinholes. It offers parallel scanning of various specimen following to a principle, where a DMD is used for illumination and a selective CCD for detection. The fundamental concepts concerning system layout and system performance as well as measurement results with a first experimental demonstrator are presented.

Ji Qi, Yingzhong Tian, Wenjun Zhang, Albert Weckenmann, Minglun Fang
3D SURFACE MICRO TOPOGRAPHY RECOVERY FROM MULTI-FOCUS IMAGES USING MODIFIED LAPLACIAN OPERATOR

Optical microscopy enables the observation of highly magnified objects and material structures on micro surfaces, however with the weakness that it can only acquire 2D images. In order to observe the areal features more accurately and intuitively, 3D surface micro topography recovery is applied to form a 3D surface model of an object from its 2D image sequence. Optical microscope has a limited depth of focus in large magnification, which makes the area within the depth of focus cleared and other area blurred. So this paper firstly acquires image sequence which obtains all useful information in one view by vertical scanning of the microscope. Secondly, each image is calculated by an appropriate focus measure operator to find the maximum focus measure value and form a 2D fused image. Then the maximum value of each pixel is accurately transferred into a distance value, forming a discrete depth map. After conducting interpolation, fitting and color mapping, a smooth and authentic 3D color model of the measured surface is obtained. Various focus measure operators such as grey level variance are used to compare their performances in 3D model recovery. The superiority of the modified Laplacian operator proposed in this paper is proved by experimenting on measured objects with different micro topography features such as ditch shaped and slope shaped structure. In addition, surface roughness information of Ra and Rz is extracted from the formed 3D models.

Page 4 of 748 Results 31 - 40 of 7479