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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Requisitos técnicos para la aplicación de sensores de tecnología láser en sistemas inteligentes de transporte (ITS)

Gallego Ripoll, María de las Nieves 22 March 2010 (has links)
Es un hecho incuestionable que las necesidades de los ciudadanos han cambiado a lo largo de los últimos tiempos. Objetos, bienes, cualidades y situaciones que antes nos eran indiferentes actualmente ocupan una elevada posición en nuestra escala de valores. Un ejemplo de ello es la seguridad que en la sociedad en la que vivimos es un activo en alza que está alcanzando cotas muy importantes. La seguridad vial se convirtió en una preocupación global en abril de 2004, cuando la Asamblea General de la Organización de las Naciones Unidad (ONU) aprobó una resolución en la que instaba a la mejora de la seguridad vial en el mundo [ONU04]. Esta preocupación se traspasó a todas las esferas de gobierno (ONU, UE, Gobiernos de España..). Así, el principal objetivo de todas las políticas y planes de seguridad vial se centran actualmente en la reducción de muertes en carretera [DGTO6a]. Uno de los escenarios donde se pone de manifiesto de forma más evidente y clara el problema de la seguridad vial y el objetivo de reducción de víctimas por accidentes de tráfico es el entorno urbano y metropolitano. Este conjunto de factores y circunstancias posiciona a la gestión de tráfico como uno de los factores estratégicos más relevantes hoy en día. Asimismo, implica a diversos sectores tales como el económico (dependencia de los combustibles), el ambiental (contaminación, ruido, emisión de gases de efecto invernadero ), la seguridad (de usuarios de la vía, tanto conductores, como peatones) y la salud (problemas respiratorios, circulatorios ). Los sistemas de transporte inteligentes, ITS (acrónimo del inglés Intelligent Transportation Systems), presentan una solución a las demandas de seguridad vial, gestión de tráfico y movilidad ciudadana, gracias al desarrollo y al uso de diversas aplicaciones y tecnologías [ITS08a, ITS8b]. La correcta gestión del tráfico rodado exige la utilización de una gran cantidad de información que presente un alto grado de fiabilidad. / Gallego Ripoll, MDLN. (2010). Requisitos técnicos para la aplicación de sensores de tecnología láser en sistemas inteligentes de transporte (ITS) [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/7381 / Palancia
2

<b>TECHNIQUES FOR REDUCING TRAFFIC MANAGEMENT CENTER CAMERA POSITIONING LATENCY FOR ACCELERATED INCIDENT RESPONSE</b>

Haydn Austin Malackowski (18339684) 10 April 2024 (has links)
<p dir="ltr">Traffic Incident Management (TIM) is an important tool for agencies to reduce secondary crashes, improve travel reliability, and ensure safety of first responders. Having “eyes” on the scene from roadside traffic cameras can assist operators to dispatch appropriate personnel, provide situational awareness, and allow for quick response when incident conditions change. Many intelligent traffic systems (ITS) centers deploy pan-tilt-zoom (PTZ) cameras that provide broad coverage but require operators to position. When incidents occur or a public safety vehicle stops for roadside assistance, Traffic Management Center (TMC) operators need to reposition cameras to monitor the event. The camera positioning time depends on operator experience, accuracy of 911 call, location, public safety radio reports, and in some cases, GPS positions. This research outlines the methodology to use GPS data sources to automate camera position to a scene for event nature verification. In general, this GPS information can come from either connected vehicles or public safety vehicles, such as Indiana Department of Transportation (INDOT) Hoosier Helpers. Implementing this research into INDOT daily operations has increased the number of events that cameras verify, while decreasing the time from event occurrence to camera verification from a median of 5 minutes to a median of approximately 90 seconds. The time is driven by the accuracy and frequency of GPS data from devices. With increased telematics polling rates and availability of enhanced vehicle data such as door open/close and seatbelt latch events, this latency is expected to further decline. </p>
3

Emergency Braking in Compact Vehicle Platoons: A Cyber-Physical Design

Krishna Murthy, Dharshan 24 March 2021 (has links)
With the advent of autonomous driving, concepts like road trains or platoons are becoming more popular. In these arrangements, vehicles travel at separations of only 5 to 10m between them. These short inter-vehicle distances allow compacting vehicle flows resulting in increased throughput on highways. In addition, there are also fuel/energy savings as the magnitude of aerodynamic resistance acting on vehicles is reduced. These benefits increase when reducing inter-vehicle separations to below 5m. However, it becomes extremely difficult to guarantee safety, especially, when braking in an emergency. The longitudinal and lateral control systems developed so far aim to achieve string stability in the cruise scenario, i.e., to prevent that small variations at the lead magnify towards the trail. Unfortunately, this has no relevance during emergency braking, since control systems incur saturation, i.e., the condition where computed output brake forces exceed those that can be applied by actuators. This is because all vehicles have to apply their maximum brake forces in order to minimize the stopping distance of the platoon and reach a complete standstill. As a result, emergency braking requires special attention and needs to be designed and verified independent of the cruise scenario. Braking in an emergency is mainly characterized by the problem of heterogeneous deceleration capabilities of vehicles, e.g., due to their type and/or loading conditions. As a result, a deceleration rate possible by one vehicle may not be achievable by its immediately leading or following vehicles. Not addressing this heterogeneity leads to inter-vehicle collisions. Moreover, transitions in the road profile increase the complexity of such brake maneuvers. Particularly, when there is a transition from a flat road to a steep downhill, an already saturated brake controller cannot counteract the effect of the downhill slope. Hence, its deceleration magnitude will be reduced, potentially leading to intra-platoon crashes that would otherwise not occur on a flat road. In this work, we first analyze the problem of emergency braking in platoons operating at inter-vehicle separations below 5m and under idealized conditions (i.e., flat road, instantaneous deceleration, etc.). For this case, we propose a cyber-physical approach based on exploiting space buffers that are present in the separations between vehicles, and compare it with straightforward schemes (such as Least Platoon Length and Least Stopping Distance) in terms of achieved aerodynamic benefits, overall platoon length, and stopping distance. We then consider realistic conditions (in particular, changing road profiles as mentioned before) and investigate how to design a brake-by-wire controller present at each vehicle that accounts for this. We further extend our proposed cyber-physical approach by adding cooperative behavior. In particular, if an individual vehicle is unable to track its assigned deceleration, it coordinates with all others to avoid inter-vehicle collisions, for which we propose a vehicle-to-vehicle (V2V) communication strategy. Finally, we present a detailed evaluation of the proposed cyber-physical approach based on high-fidelity vehicle models in Matlab/Simulink. Even though more work is needed towards a real-life implementation, our simulation results demonstrate benefits by the proposed approach and, especially, its feasibility.
4

Capteurs de position innovants : application aux Systèmes de Transport Intelligents dans le cadre d'un observatoire de trajectoires de véhicules / New position sensors : application to Intelligent Transport Systems within the context of estimation of vehicule trajectories

Aubin, Sébastien 12 December 2009 (has links)
Améliorer la sécurité routière passe par une meilleure compréhension des causes d'accidents. Il est donc nécessaire de développer des observatoires discrets pour étudier la manière de conduire de tous les automobilistes. Une partie de cette analyse implique l'utilisation de capteurs mesurant les trajectoires des véhicules sur une portion de route. Deux capteurs innovants ont été crées pour pallier au manque de capteurs suffisamment précis pour ces travaux de recherche : le premier est un capteur à fibres optiques présentant une succession de réseaux de Bragg et le second, protégé par un brevet, est fondé sur une technologie résistive. Le premier repère la déformation locale de fibres optiques noyées à moins d'un centimètre sous la surface de la chaussée. Il utilise la variation de longueurs d'onde engendré par l'extension de la fibre à la zone de contact roue - sol. En utilisant un algorithme adéquat, il est insensible à la température. Le second est constitué de deux conducteurs dont un est résistif. Le poids du véhicule engendre un contact électrique entre les deux conducteurs, transformant la résistance électrique de l'ensemble. Les modèles développés, électrique ainsi que de variation thermique, permettent sa meilleure utilisation. Ils ont été soumis à une expérimentation sur une route départementale. Le capteur optique s'avère plus performant mais coûteux. Le deuxième n'est pas assez robuste mais présente des perspectives intéressantes. / This action stake is not technology for itself. It is a great help the development of new safety functions, e.g. the estimation of driver’s behaviour based uponthe vehicle’s trajectory. This trajectory is determined via two sensors we developed. This system must not disturb the driver and should therefore remain invisible to him. The first one is a fiber Bragg grating (FBG) sensor. It detects local strain due to the vehicle weight. The fiber is embedded in the road thanks to resin used in other traffic sensors. The vehicle location is spotted according to the variations of Bragg wavelengths. The fiber extension located under the ground - wheel contact zone changes the step of the Bragg grating. The second one is based upon two conductors. One of them has a grater electrical resistance. The vehicle’s weight creates a link between the two conductors. The resulting electrical resistance provides a lateral position estimation of the vehicle. Electrical and thermic models and simulation even increase the sensor reliability. A caveat is lodged. Both of them were tested on a secondary road. To put in a nutshell, the FBG sensor gives better results but is very expensive (sensors and interrogator too). The resistance sensor is not much raw nevertheless it has interesting perspectives.
5

Verkehrstelematik

Krimmling, Jürgen, Lehnert, Martin 22 May 2019 (has links)
Die Verkehrstelematik, im Englischen als Intelligent Transport Systems (ITS) bezeichnet, kann durch die Verbindung von Telekommunikation, Informatik und Automatisierung wesentlich zur Sicherung der Mobilität beitragen. Dabei kann durch Erfassen, Übermitteln, Verarbeiten und Darstellen von Verkehrsdaten in Telematiksystemen der Verkehr prognostiziert, gesteuert, gelenkt, geleitet und organisiert werden. An der Fakultät Verkehrswissenschaften „Friedrich List“ der TU Dresden beschäftigt sich das Institut für Verkehrstelematik mit verkehrstelematischen Fragestellungen und Anwendungen. An der Professur für Verkehrsleitsysteme und -prozessautomatisierung stehen dabei Lehre und Forschung in den Themengebieten Verkehrs- und Betriebsleitsysteme, Verkehrssteuerungstechnik, Verkehrsprozessautomatisierung und Verkehrsmanagement sowohl des schienengebundenen als auch des straßengebundenen Verkehrs im Vordergrund. Um aktuelle Forschungs- und Entwicklungsergebnisse einem breiten Fachpublikum verfügbar zu gestalten, veröffentlicht die Professur mit der Schriftenreihe „Verkehrstelematik“ in loser Folge interessante Forschungsthemen und Beitrage aus ihrem unmittelbaren Wirkungsfeld, der Verkehrstelematik allgemein und darüber hinaus auch Beitrage zu interdisziplinär aufgestellten Fragestellungen. Damit verbunden ist die Hoffnung, dass die aktuellen Forschungsergebnisse in die Praxis einfließen und dabei helfen, den Verkehr flüssiger, ressourcenschonender und effizienter zu gestalten. / Traffic telematics and Intelligent Transport Systems (ITS) can significantly contribute to securing mobility by combining telecommunications, information technology and automation. By capturing, transmitting, processing and displaying traffic data in traffic emblematic systems, the traffic can be predicted, controlled, directed, managed and organized. The Institute of Transport Telematics at the Faculty of Traffic Sciences 'Friedrich List' of the Technische Universität Dresden (TUD) deals with traffic telematics issues and applications. Teaching and research in the fields of traffic guidance and operation control systems, traffic control technology, process automation and traffic management of both rail-bound and road-bound traffic are in the focus of the Chair of Traffic Control and Process Automation. In order to make current research and development results available to a broad professional audience, the professorship publishes interesting research topics and contributions from their immediate field of action, namely traffic telematics in general, and also contributions to interdisciplinary issues with the series 'Verkehrstelematik'. Linked to this is the hope that current research findings will be put into practice and help to make traffic smoother, Eco-friendly and more efficient.
6

IN - eine verteilte Service-Plattform mobiler Prozeßarchitekturen für verkehrstelematische Anwendungen / IN - adistributed service platform of mobile process architectures for traffic telematic applications / traffic telematics IN (eng)

Riegelmayer, Wolfgang P. 14 February 2006 (has links) (PDF)
Der Paradigmenwechsel zur Entwicklungsmethodik innerhalb verteilter Kommunikationssysteme schlägt sich auch in der Telematik zum Anwendungspotential und Systemkomplexität nieder. Dies liefert eine neue Auffasung dessen, was den transparenten Datenkanal ausmacht.
7

IN - eine verteilte Service-Plattform mobiler Prozeßarchitekturen für verkehrstelematische Anwendungen

Riegelmayer, Wolfgang P. 09 January 2006 (has links)
Der Paradigmenwechsel zur Entwicklungsmethodik innerhalb verteilter Kommunikationssysteme schlägt sich auch in der Telematik zum Anwendungspotential und Systemkomplexität nieder. Dies liefert eine neue Auffasung dessen, was den transparenten Datenkanal ausmacht.

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