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Vision stéréoscopique temps-réel pour la navigation autonome d'un robot en environnement dynamique / Maxime Derome (2017)
Titre : Vision stéréoscopique temps-réel pour la navigation autonome d'un robot en environnement dynamique Type de document : Thèse/HDR Auteurs : Maxime Derome, Auteur ; Guy Le Besnerais, Directeur de thèse Editeur : Paris-Orsay : Université de Paris 11 Paris-Sud Centre d'Orsay Année de publication : 2017 Importance : 162 p. Format : 21 x 30 cm Note générale : Bibliographie
Thèse de doctorat de l'Université Paris-Saclay préparée à l’Université Paris-Sud,
École doctorale n°580 Sciences et technologies de l’information et de la communication (STIC)
Spécialité de doctorat : Mathématiques et informatiqueLangues : Français (fre) Descripteur : [Vedettes matières IGN] Photogrammétrie numérique
[Termes IGN] appariement d'images
[Termes IGN] détection d'objet
[Termes IGN] estimation de pose
[Termes IGN] estimation par noyau
[Termes IGN] estimation statistique
[Termes IGN] navigation autonome
[Termes IGN] odomètre
[Termes IGN] propagation d'erreur
[Termes IGN] robot mobile
[Termes IGN] temps réel
[Termes IGN] trajectoire (véhicule non spatial)
[Termes IGN] vision par ordinateur
[Termes IGN] vision stéréoscopiqueIndex. décimale : THESE Thèses et HDR Résumé : (auteur) L’objectif de la thèse est de concevoir un système de perception stéréoscopique embarqué, permettant une navigation robotique autonome en présence d’objets mobiles. Pour pouvoir naviguer en environnement inconnu et en présence d’objets mobiles quelconques, nous avons adopté une approche purement géométrique reposant sur l’estimation de la disparité stéréo, du flot optique et du flot de scène. Pour assurer une couverture maximale du champ visuel, nous avons employé des méthodes d'estimation denses qui traitent chaque pixel de l'image. Enfin, puisque les algorithmes utilisés doivent s’exécuter en embarqué sur un robot, nous nous sommes efforcé de sélectionner ou concevoir des algorithmes rapides, pour nuire au minimum à la réactivité du système. Cette thèse présente plusieurs contributions. Nous avons proposé une nouvelle approche pour l’estimation du flot de scène, en combinant des algorithmes d’odométrie visuelle, d’appariement stéréo et de flot optique. Son implémentation sur GPU permet une estimation du flot de scène à cadence vidéo sur les images du dataset KITTI. Une méthode de détection dense d’objets mobiles a aussi été proposée, en modélisant statistiquement et en propageant toutes les erreurs de mesures. Enfin, nous avons validé expérimentalement sur un petit robot terrestre ces algorithmes de perception, en les couplant à un module de commande prédictive. L’expérience montre que le système de perception proposé est suffisamment rapide pour permettre au robot de détecter un objet mobile et d’adapter à la volée sa trajectoire afin d’éviter une collision. Note de contenu : Introduction
1 - Perception 3D à Partir d'un Banc Stéréoscopique
2 - Estimations Temporelles : Odométrie Stéréo, Flot Optique, Flot de scène
3 - Détection Dense d'Objets Mobiles à Partir d'un Banc Stéréo en déplacement
4 - Programmation sur GPU d'Algorithmes Temps-Réel et Application à la Navigation Autonome en Robotique
ConclusionNuméro de notice : 21575 Affiliation des auteurs : non IGN Thématique : IMAGERIE/INFORMATIQUE/MATHEMATIQUE Nature : Thèse française Note de thèse : Thèse de doctorat : Mathématiques et informatique : Université Paris-Saclay : 2017 nature-HAL : Thèse DOI : sans En ligne : http://www.theses.fr/2017SACLS156 Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=90578 Visualization of two-phase flow dynamics: Techniques for droplet interactions, interfaces, and material transport / Grzegorz Karol Karch (2017)
Titre : Visualization of two-phase flow dynamics: Techniques for droplet interactions, interfaces, and material transport Type de document : Thèse/HDR Auteurs : Grzegorz Karol Karch, Auteur ; Thomas Ertl, Directeur de thèse ; H. Theisel, Directeur de thèse Editeur : Stuttgart : University of Stuttgart Année de publication : 2017 Importance : 180 p. Format : 21 x 30 cm Note générale : Bibliography
Von der Fakultät Informatik, Elektrotechnik und Informationstechnik und dem Stuttgart Research Centre for Simulation Technology der Universität Stuttgart zur Erlangung der Würde eines Doktors der Naturwissenschaften (Dr. rer. nat.), genehmigte AbhandlungLangues : Anglais (eng) Descripteur : [Termes IGN] analyse visuelle
[Termes IGN] mécanique des fluides
[Termes IGN] visualisation 4DIndex. décimale : THESE Thèses et HDR Résumé : (auteur) Computational visualization allows scientists and engineers to better understand simulation data and gain insights into the studied natural processes. Particularly in the field of computational fluid dynamics, interactive visual presentation is essential in the investigation of physical phenomena related to gases and liquids. To ensure effective analysis, flow visualization techniques must adapt to the advancements in the field of fluid dynamics that benefits substantially from the growing computational power of both commodity desktops and supercomputers on the one hand, and steadily expanding knowledge about fluid physics on the other. A prominent example of these advances can be found in the research of two-phase flow with liquid droplets and jets, where high performance computation and sophisticated algorithms for phase tracking enable well resolved and physically accurate simulations of liquid dynamics. Yet, the field of two-phase flow has remained largely unexplored in visualization research so far, leaving the scientists and engineers with a number of challenges when analyzing the data. These include the difficulty in tracking and investigating topological events in large droplet groups, high complexity of droplet dynamics due to the involved interfaces, and a limited choice of high quality interactive methods for the analysis of related transport phenomena. It is therefore the aim of this thesis to address these challenges by providing a multi-scale approach for the visual investigation of two-phase flow, with the focus on the analysis of droplet interaction, fluid interfaces, and material transport. To address the problem of analyzing highly complex two-phase flow simulations with droplet groups and jets, a linked-view approach with three-dimensional and abstract space-time graph representation of droplet dynamics is proposed. The interactive brushing and linking allows for general exploration of topological events as well as detailed inspection of dynamics in terms of oscillations and rotations of droplets. Another approach further examines the separation of liquid phases by segmenting liquid volumes according to their topological changes in future time. For visualization, boundary surfaces of these volume segments are extracted that reveal intricate details of droplet topology dynamics. Additionally, within this framework, visualization of advected particles corresponding to arbitrarily selected segment provides useful insights into the spatio-temporal evolution of the segment. The analysis of interfaces is necessary to understand the interplay of interface dynamics and the dynamics of droplet interactions. A commonly used technique for interface tracking in the volume of fluid-based simulations is the piecewise linear approximation which, although accurate, can affect the quality of the simulation results. To study the influence of the interface reconstruction on the phase tracking procedure, a visualization method is presented that extracts the interfaces by means of the first-order Taylor approximation, and provides several derived quantities that help assess the simulation results in relation to the interface reconstruction quality. The liquid interface is further investigated from the physical standpoint with an approach based on quantities derived from velocity and surface tension gradients. The developed method supports examination of surface tension forces and their impact on the interface instability, as well as detailed analysis of interface deformation characteristics. A line of research important for engineering applications is the analysis of electric fields on droplet interfaces. It is, however, complicated by higher-order elements used in the simulations to preserve field discontinuities. A visualization method has been developed that correctly visualizes these discontinuities at material boundaries. Additionally, the employed space-time representation of the droplet-insulator contact line reveals characteristics of electric field dynamics. The dynamics of droplets are often examined assuming single-phase flow, for instance when the internal material transport is of interest. From the visualization perspective, this allows for adaption of traditional vector field visualization techniques to the investigation of the studied phenomena. As one such concept, dye based visualization is proposed that extends the transport analysis to advection-diffusion problems, therefore revealing true transport behavior. The employed high quality advection preserves fine details of the dye, while the implementation on graphics processing units ensures interactive visualization. Several streamline-based concepts are applied in space-time representation of 2D unsteady flow. By interpreting time as the third spatial dimension, many 3D streamline-based visualization techniques can be applied to investigate 2D unsteady flow. The introduced vortex core ribbons support the examination of vortical flow behavior by revealing rotation near the core lines. For the study of topological structures, a method has been developed that extracts separatrices implicitly as boundaries of regions with different flow behavior, and therefore avoids potentially complicated explicit extraction of various topological structures. All proposed techniques constitute a novel multi-scale approach for visual analysis of two-phase flow. The analysis of droplet interactions is addressed with visualization of the phenomena leading to breakups and with detailed visual inspection of these breakups. On the interface level, techniques for the interface analysis give insights into the simulation quality, mechanisms behind topology changes, as well as the behavior of electrically charged droplets. Further down the scale, the dye-based visualization, streamline-based concepts for space-time analysis, and the implicit extraction of flow topology allow for the investigation of droplet internal transport as well as general single-phase flow scenarios. The applicability of the proposed methods extends, in a varying degree, beyond the use in two-phase flow. Their usability is demonstrated on data from simulations based on Navier-Stokes equations that exemplify practical problems in the research of fluid dynamics. Note de contenu : Introduction
1 - Fundamentals and State of the Art
2 - Visualization of Interactions in Droplet Groups
3 - Visualization of Liquid Interface Dynamics
4 - Visualization Approaches for Material Transport
ConclusionNuméro de notice : 21572 Affiliation des auteurs : non IGN Nature : Thèse étrangère Note de thèse : Doktor thesis : Sciences naturelles : Stuttgart : 2017 En ligne : https://elib.uni-stuttgart.de/handle/11682/9701 Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=90563 Travel time estimation at intersections based on low-frequency spatial-temporal GPS trajectory big data / Luliang Tang in Cartography and Geographic Information Science, vol 43 n° 5 (November 2016)
[article]
Titre : Travel time estimation at intersections based on low-frequency spatial-temporal GPS trajectory big data Type de document : Article/Communication Auteurs : Luliang Tang, Auteur ; Zihan Kan, Auteur ; Xia Zhang, Auteur ; et al., Auteur Année de publication : 2016 Article en page(s) : pp 417 - 426 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Analyse spatiale
[Termes IGN] carrefour
[Termes IGN] coordonnées GPS
[Termes IGN] dimension temporelle
[Termes IGN] données massives
[Termes IGN] durée de trajet
[Termes IGN] fréquence
[Termes IGN] logique floue
[Termes IGN] taxi
[Termes IGN] trafic routier
[Termes IGN] trajectoire (véhicule non spatial)
[Termes IGN] Wuhan (Chine)Résumé : (Auteur) Intersections are the critical parts where different traffic flows converge and change directions, forming “bottlenecks” and “clog points” in urban traffic. Intersection travel time is an important parameter for public route planning, traffic management, and engineering optimization. Based on low-frequency spatial-temporal Global Positioning System (GPS) trace data, this article presents a novel method for estimating intersection travel time. The proposed method first analyzes the different travel patterns of vehicles through an intersection, then determines the range of an intersection dynamically and reasonably, and obtains traffic flow speed and delay at the intersection under different travel patterns using a fuzzy fitting approach. Finally, the average intersection travel time is estimated from traffic flow speed and delay and intersection range in different travel patterns. Wuhan road network data and GPS trace data from taxicabs were tested in the experiments and the results show that the proposed method can improve the accuracy of travel time estimation at city intersections. Numéro de notice : A2016-692 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/POSITIONNEMENT Nature : Article DOI : 10.1080/15230406.2015.1130649 En ligne : https://doi.org/10.1080/15230406.2015.1130649 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=82029
in Cartography and Geographic Information Science > vol 43 n° 5 (November 2016) . - pp 417 - 426[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 032-2016051 RAB Revue Centre de documentation En réserve L003 Disponible Use of the gyrotheodolite in underground networks of long high-speed railway tunnels / J. Velasco-Gómez, in Survey review, vol 48 n° 350 (September 2016)
[article]
Titre : Use of the gyrotheodolite in underground networks of long high-speed railway tunnels Type de document : Article/Communication Auteurs : J. Velasco-Gómez,, Auteur ; J. F. Prieto, Auteur ; I. Molina, Auteur ; et al., Auteur Année de publication : 2016 Article en page(s) : pp 329 - 337 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Navigation et positionnement
[Termes IGN] déviation de la verticale
[Termes IGN] Espagne
[Termes IGN] géoïde
[Termes IGN] guidage de forage
[Termes IGN] guidage de véhicules
[Termes IGN] gyrothéodolite
[Termes IGN] lever souterrain
[Termes IGN] tunnel
[Termes IGN] voie ferréeRésumé : (auteur) The quality of geodetic networks for guiding Tunnel Boring Machines (TBMs) inside long tunnels depends largely on the correct use of a gyroscope. These networks are based on a series of control points at the tunnel entrance, and link each station by means of survey observations as they advance along the tunnel. Once, the networks are used to guide the TBM, they are no longer checked again. It is necessary to perform high accuracy astronomical observations to stars in order to determine the gyrotheodolite constant. Since astronomical observations cannot be made inside tunnels, geodetic azimuths have to be used for the computations. However, these azimuths cannot theoretically be compared with the astronomical azimuths obtained by the gyrotheodolite. An alternative is to compute the instrument constant using the values of the deviation of the vertical derived from a geoid model. That is the approach used in this work where a methodology for the design of underground networks in long tunnels is also presented. This procedure has been implemented during the construction of the Guadarrama and Pajares high-speed railway tunnels (Spain). Numéro de notice : A2016-640 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1179/1752270615Y.0000000043 En ligne : https://doi.org/10.1179/1752270615Y.0000000043 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=81845
in Survey review > vol 48 n° 350 (September 2016) . - pp 329 - 337[article]A frequency-domain imaging algorithm for highly squinted SAR mounted on maneuvering platforms with nonlinear trajectory / Zhenyu Li in IEEE Transactions on geoscience and remote sensing, vol 54 n° 7 (July 2016)
[article]
Titre : A frequency-domain imaging algorithm for highly squinted SAR mounted on maneuvering platforms with nonlinear trajectory Type de document : Article/Communication Auteurs : Zhenyu Li, Auteur ; Mengdao Xing, Auteur ; Yi Liang, Auteur ; et al., Auteur Année de publication : 2016 Article en page(s) : pp 4023 - 4038 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image radar et applications
[Termes IGN] accélération
[Termes IGN] données Doppler
[Termes IGN] mesurage de la fréquence
[Termes IGN] radar à antenne synthétique
[Termes IGN] trajectoire (véhicule non spatial)Résumé : (Auteur) The imagery of highly squinted synthetic aperture radar mounted on maneuvering platforms with nonlinear trajectory is a challenging task due to the existence of acceleration and the cross-range-dependent range migration and Doppler parameters. In order to accommodate these issues, a frequency-domain imaging algorithm based on tandem two-step nonlinear chirp scaling (TNCS) with small aperture is proposed. For the cross-range-dependent range cell migration (RCM) caused by the linear range walk correction and acceleration, the first-step NCS is introduced to suppress this dependence and realize the unified RCM correction. Based on the differences between full-aperture and small-aperture data in the cross-range processing, the second-step NCS is introduced in frequency domain to equalize the cross-range-dependent Doppler parameters, for cross-range processing is more sensitive to the cross-range dependence than range processing. Furthermore, a novel geometric correction method based on inverse projection is utilized to eliminate the negative effects caused by the imaging processing. Simulation results and real data processing are presented to validate the proposed approach. Numéro de notice : A2016-877 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2016.2535391 En ligne : https://doi.org/10.1109/TGRS.2016.2535391 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=83040
in IEEE Transactions on geoscience and remote sensing > vol 54 n° 7 (July 2016) . - pp 4023 - 4038[article]PermalinkModeling and simulation of glacier avalanche: a case study of Gayari sector glaciers Hazards assessment / Muhammad Ashan Mahboob in IEEE Transactions on geoscience and remote sensing, vol 53 n° 11 (November 2015)PermalinkDetection of high speed railway track static regularity with laser trackers / L. Yao in Survey review, vol 47 n° 343 (July 2015)PermalinkAutomatic selection of landmarks for navigation guidance / Rui Zhu in Transactions in GIS, vol 19 n° 2 (April 2015)PermalinkPermalinkVisualization, statistical analysis, and mining of historical vessel data / Sabarish Senthilnathan Muthu (2015)PermalinkOrbit computation of the TELECOM-2D satellite with a genetic algorithm / Florent Deleflie in Proceedings of the International astronomical union, vol 9 S310 (Juillet 2014)PermalinkA near-real-time automatic orbit determination system for COSMIC and its follow-on satellite mission: analysis of orbit and clock errors on radio occultation / Yi-Shan Li in IEEE Transactions on geoscience and remote sensing, vol 52 n° 6 Tome 1 (June 2014)PermalinkLes principes variationnels en physique / Jean-Louis Basdevant (2014)PermalinkA spatio-temporal graph model for marine dune dynamics analysis and representation / Rémy Thibaud in Transactions in GIS, vol 17 n° 5 (October 2013)PermalinkUsing virtual reality and percolation theory to visualize fluid flow in porous media / Carlos Magno De Lima in Geoinformatica, vol 17 n° 4 (October 2013)PermalinkFrom lab to road test: Using a reference vehicle for solving GNSS localization challenges, road testing the VERT: a data collection campaign, applications of the VERT: EGNOS, urban integrity and beyond / Miguel Ortiz in Inside GNSS, vol 8 n° 5 (September - October 2013)PermalinkPilotage de machines de chantier : Utilisation de systèmes de mensuration intelligents dans les travaux routiers et de génie civil / G. Roulier in Géomatique suisse, vol 111 n° 3 (01/03/2013)PermalinkPermalinkÉtude et optimisation du fonctionnement des systèmes 3D de positionnement Topcon sur les machines de travaux publics / Bastien Lopes (2013)PermalinkPermalinkIntegrating Landsat-7 imagery with physics-based models for quantitative mapping of coastal waters near river discharges / Nima Pahlevan in Photogrammetric Engineering & Remote Sensing, PERS, vol 78 n° 11 (November 2012)PermalinkTrajectory-based registration of 3d lidar point clouds acquired with a mobile mapping system / Adrien Gressin in ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences, vol I-3 (2012)PermalinkPNN query processing on compressed trajectories / S. Shang in Geoinformatica, vol 16 n° 3 (July 2012)PermalinkEvolution morphodynamique interannuelle du littoral sud sur la Gironde / A. Dehouck in Revue Française de Photogrammétrie et de Télédétection, n° 197 (Juin 2012)Permalink