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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

[en] DYNAMIC VEHICLE PLATOON FORMATION: A SELF-ORGANIZING APPROACH / [pt] FORMAÇÃO DE COMBOIOS VEICULARES DINÂMICOS: UMA ABORDAGEM DE AUTO-ORGANIZAÇÃO

LAURO DE LACERDA CAETANO 11 May 2020 (has links)
[pt] A auto-organização possui conceitos amplamente utilizados em diversos domínios que vão desde a biologia até aplicações em sistemas distribuí- dos. Além disso, os seus princípios servem como base e inspiração para a modelagem e desenvolvimento de tecnologias contemporâneas, como os drones e os sistemas autônomos. Nos últimos anos, os sistemas autônomos de direção e suas aplicações têm gerado um grande interesse na sociedade, principalmente pelo potencial de melhorar a segurança e a eficiência dos fluxos rodoviários. Neste trabalho, investigamos os principais aspectos de auto-organização presentes na formação de comboios veiculares dinâmicos. Ademais, modelamos e desenvolvemos um protocolo de gerenciamento de comboios baseado em fundamentos de auto-organização. Finalmente, demonstramos que o protocolo preserva a segurança e estabilidade do comboio em um cenário onde há redução de faixas no ambiente rodoviário. / [en] Self-organization has concepts widely used in many fields ranging from biology to applications in distributed systems. Besides, its principles serve as the basis and inspiration for the modeling and the development of contemporary technologies, such as drones and autonomous systems. In recent years, autonomous driving systems and their applications have instigated a great interest in society, primarily due to the potential of improving the safety and efficiency of road traffic. In this work, we investigate the main aspects of self-organization present in dynamic vehicle platoons. Also, we model and develop a platoon management protocol based on self-organizing principles. Finally, we demonstrate that the protocol maintains the safety and stability of the platoon in a lane reduction scenario in the road environment.
2

Contribution à la commande d'un train de véhicules intelligents / Contribution to intelligent vehicle platoon control

Zhao, Jin 02 September 2010 (has links)
Ce mémoire est consacré à la mise en œuvre de commandes d'un train de véhicules intelligents sur autoroute ayant pour objectifs principaux de réduire la congestion et d’améliorer la sécurité routière. Après avoir présenté l'état de l'art sur des systèmes de conduite automatisée, des modèles de la dynamique longitudinale et latérale du véhicule sont présentés. Ensuite, des stratégies de contrôle longitudinal et latéral sont étudiées.D'abord, le contrôle longitudinal est conçu pour être hiérarchique avec un contrôleur de niveau supérieur et un contrôleur de niveau inférieur. Pour celui de niveau supérieur, une régulation d'inter-distance SSP (Safety Spacing Policy) est proposée. Nous avons constaté que la SSP peut assurer la stabilité de la chaîne et la stabilité des flux de trafic et augmenter ainsi la capacité de trafic. Puis, pour celui de niveau inférieur, une loi de commande floue coordonnée est proposée pour gérer l'accélérateur et le freinage. Ensuite, une loi de commande multi-modèle floue est conçue pour le contrôle latéral. De plus, pour réaliser des transformations lisses entre les différentes opérations latérales, une architecture de contrôle hiérarchique est proposée. Puis, l'intégration des commandes longitudinale et latérale est étudiée. Enfin, l'estimation des variables d’états du véhicule est discutée. Un filtre de Kalman-Bucy est conçu pour estimer les états du véhicule. En outre, un prototype de véhicule intelligent à échelle réduite est également présenté. Les performances des divers algorithmes de commande proposés ont été testées par simulations, et les résultats ont été confirmés par les premières expériences en utilisant le prototype / This PhD thesis is dedicated to the control strategies for intelligent vehicle platoon in highway with the main aims of alleviating traffic congestion and improving traffic safety. After a review of the different existing automated driving systems, the vehicle longitudinal and lateral dynamic models are derived. Then, the longitudinal control and lateral control strategies are studied respectively. At first, the longitudinal control system is designed to be hierarchical with an upper level controller and a lower level controller. For the upper level controller, a safety spacing policy (SSP) is proposed. It is shown that the proposed SSP can ensure string stability, traffic flow stability and improve traffic capacity. Then, a coordinated throttle and brake fuzzy controller (lower level controller) is designed, in which a logic switch is designed to coordinate the two actuators (throttle and brake pedals). Second, for the lateral control, a multi-model fuzzy controller is designed. And a hierarchical lateral control architecture is also proposed, which can effectuate flexible switch between different lateral operations. After that, the integration of the longitudinal controller and lateral controller is also studied. Finally, the estimation of vehicle states is discussed. A Kalman-Bucy filter is designed to estimate vehicle states in lateral dynamics. Moreover, a reduced scale multi-sensor intelligent vehicle prototype is also presented. The performances of the divers control algorithms proposed in this thesis have been tested in numerical simulations, and the first step experiments with the reduced scale vehicle prototype gave encouraging results

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