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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.
161

Contrôle et optimisation des systèmes de transport intelligents dans le voisinage des intersections / Control and optimization for intelligent transportation systems in vicinity of intersections

Liu, Bing 09 September 2016 (has links)
Cette thèse est consacrée à étudier les applications potentielles de véhicules autonomes et communications V2X pour construire les systèmes de transport intelligents. Premièrement, le comportement de caravane dans un environnement de véhicule connecté est étudié. Un algorithme de commande de caravane est conçu pour obtenir l'espacement sécuritaire ainsi que la conformité de la vitesse et de l'accélération. Deuxièmement, à plus grande échelle, les caravanes autour d'une intersection sont considérées. Le débit pendant une période de signal de trafic peut être amélioré en tirant profit de la capacité redondante de la route. Dans diverses contraintes, les véhicules peuvent choisir d'accélérer et rejoindre la caravane précédente ou à décélérer de déroger à l'actuel. Troisièmement, une intersection sans signalisation en VANET est considérée. Dans des conditions de faible trafic, les véhicules peuvent réguler leur vitesse avant d'arriver à l'intersection en fonction du temps d'occupation de la zone de conflit (TOZC) stocké au niveau du gestionnaire, afin qu'ils puissent traverser l'intersection sans collision ni arrêt. Le délai peut être réduit en conséquence. Enfin, un algorithme de gestion d'intersection autonome universelle, qui peut fonctionner même avec le trafic lourd, est développé. Le véhicule cherche à sécuriser les fenêtres entrant dans le TOZC. Ensuite, sur la base des fenêtres trouvées et le mouvement du véhicule qui précède, les trajectoires des véhicules peuvent être planifiées en utilisant une méthode de programmation dynamique segmentée. Tous les algorithmes conçus sont testés et vérifiés avec succès par des simulations dans scénarios différents / This thesis is devoted to study the potential applications of autonomous vehicles and V2X communications to construct the intelligent transportation systems. Firstly, the behavior of platoon in connected vehicle environment is studied. A platoon control algorithm is designed to obtain safe spacing as well as accordance of velocity and acceleration for vehicles in the same lane. Secondly, in larger scale, the platoons around an intersection are considered. The throughput in a traffic signal period can be improved by taking advantage of the redundant road capacity. Within diverse constraints, vehicles can choose to accelerate to join in the preceding platoon or to decelerate to depart from the current one. Thirdly, an unsignalized intersection in VANET is considered. In light traffic conditions, vehicles can regulate their velocities before arriving at the intersection according to the conflict zone occupancy time (CZOT) stored at the manager, so that they could get through the intersection without collision or stop. The delay can be reduced accordingly. Finally, an universal autonomous intersection management algorithm, which can work even with heavy traffic, is developed. The vehicle searches for safe entering windows in the CZOT. Then based on the found windows and the motion of preceding vehicle, the trajectories of vehicles can be planned using a segmented dynamic programming method. All the designed algorithms are successfully tested and verified by simulations in various scenarios
162

Analyse de Performances de Régulateurs de Vitesse Adaptatifs Coopératifs / Cooperative Adaptive Cruise Control Performance Analysis

Sun, Qi 15 December 2016 (has links)
Cette thèse est consacrée à l'analyse de performance de Régulateurs de Vitesse Adaptatifs Coopératifs(CACC) pour un train de véhicules intelligents afin de réduire la congestion du trafic et améliorer la sécurité routière.Premièrement, la politique d'espacement, à Intervalles Constants de Temps (CTH) est introduite. Basé sur cette politique d'espacement, un nouveau système décentralisé de Deux-Véhicules-Devant CACC (TVACACC) est proposé, dans lequel l'accélération souhaitée de deux véhicules précédents est prise en compte. Ensuite, la stabilité de la chaîne du système proposé est analysée théoriquement. Il est démontré que grâce à l'aide de la communication multiple entre véhicules, une meilleure stabilité de la chaîne est obtenue par rapport au système conventionnel. Un train de véhicules dans le scénario Stop-and-Go est simulé avec une communication parfaite puis dégradée. Le système proposé donne un comportement stable de la chaîne, correspondant à l'analyse théorique.Deuxièmement, une technique de dégradation pour CACC est présentée comme stratégie alternative lorsque la communication sans fil est partiellement ou complètement perdue. La stratégie proposée, appelée DTVACACC, utilise le filtre de Kalman pour estimer l'accélération actuelle du véhicule précédent qui remplace l'accélération souhaitée. Il est démontré que la performance pour le DTVACACC, peut être maintenue à un niveau beaucoup plus élevé.Enfin, une approche d’Apprentissage par Renforcement (RL) pour système CACC est proposée. L' algorithme politique- gradient est introduit pour réaliser le contrôle longitudinal . Ensuite, la simulation a montré que cette nouvelle approche de RL est efficace pour CACC / This PhD thesis is dedicated to the performance analysis of Cooperative Adaptive Cruise Control (CACC) system for intelligent vehicle platoon with the main aims of alleviating traffic congestion and improving traffic safety. At first, the Constant Time Headway (CTH) spacing policy for vehicle platoon is introduced. Based on this spacing policy, a novel decentralized Two-Vehicle-Ahead CACC (TVACACC) system is proposed, in which the desired acceleration of two front vehicles is taken into account. Then the string stability of the proposed system is theoretically analyzed. It is shown that by using the multiple wireless communication among vehicles, a better string stability is obtained compared to the conventional system. Vehicle platoon in Stop-and-Go scenario is simulated with both normal and degraded communication.Secondly, a graceful degradation technique for CACC was presented, as an alternative fallback strategy when wireless communication is lost or badly degraded. The proposed strategy, which is referred to DTVACACC, uses Kalman filter to estimate the preceding vehicle’s current acceleration as a replacement of the desired acceleration. It is shown that the performance is maintained at a much higher level.Finally, a Reinforcement Learning (RL) approach of CACC system is proposed. The policy-gradient algorithm is introduced to achieve the longitudinal control. Then simulation has shown that this new RL approach results in efficient performance for CACC.
163

Evolução de uma unidade de gerenciamento eletrônico de um motor VW 2.0L e desenvolvimento de controle de cruzeiro: Projeto Otto IV / Enhancement of an electronic management unit for a VW 2.0L engine and development of cruise control: Otto IV Project.

Pereira, Bruno César Fernandes 25 August 2017 (has links)
Com o passar do tempo, nota-se um aumento gradativo da demanda por veículos mais econômicos e que disponham de itens capazes de aumentar o conforto e a segurança. Citase, como exemplo, o controle de cruzeiro (Cruise Control) que, atualmente presente em diversos veículos, é responsável por controlar a velocidade do veículo de maneira autônoma, sem a necessidade de intervenção do condutor no pedal de aceleração, resultando em um aumento de conforto ao reduzir o esforço para dirigir, além de prover efetividade para manter a velocidade do veículo em torno de um valor desejado. Neste contexto, o presente trabalho apresenta o desenvolvimento de um controlador de cruzeiro para operar em um veículo modelo Volkswagen Polo Sedan 2.0L 2004, o qual não possui este recurso em seu estado de fábrica. Para a implementação deste recurso, o trabalho faz uso de uma unidade de gerenciamento eletrônico (conhecida também por Electronic Control Unit - ECU) desenvolvida em 2013, no âmbito do projeto Otto II (PEREIRA, 2013), para controle do motor presente no respectivo veículo, viabilizando, desta forma, a validação do controle de cruzeiro por meio de testes utilizando o veículo em um dinamômetro inercial. Entretanto, previamente ao projeto do controlador de cruzeiro, o presente trabalho teve como foco o aperfeiçoamento do funcionamento desta ECU, visando a sua evolução no que diz respeito ao estado da arte de unidades de gerenciamento eletrônico de motores. Para isto, em sua primeira fase, o trabalho realizou diversas melhorias nas malhas de controle já existentes no firmware de 2013, tais como controle de marcha lenta, controle da borboleta eletrônica e controle de partida. Ao mesmo tempo, novos recursos foram implementados em firmware: controle de torque, controle da mistura ar/combustível em malha fechada (sonda lambda), segurança na comunicação entre blocos da ECU, identificação de marcha, suporte para diagnóstico via OBD-II, dentre outros. Além destas atividades envolvendo desenvolvimento de firmware, o trabalho, ainda em sua primeira fase, promoveu o desenvolvimento de uma nova ferramenta de software que, além de ser capaz de monitorar diversos parâmetros da ECU em tempo real, integra diversas funções, tais como função de computador de bordo alternativo, opção para controle do motor através da simulação do pedal de aceleração, opção para alteração da rotação de marcha lenta e função para automatização do ensaio de identificação do veículo (tarefa necessária para o projeto do controlador de cruzeiro). / Over time, there is a gradual increase of the demand for economical vehicles equipped with items capable of increasing the comfort and safety. As an example, the Cruise Control, which is already available in several vehicles, is responsible to control the vehicle speed in an autonomous manner, without the driver intervention on the throttle pedal. As a result, a greater comfort is achieved by reducing the effort to drive, besides providing effectiveness to keep the vehicle speed around a desired value. In this context, this project aims the development of a Cruise Control applied to a vehicle Volkswagen Polo Sedan 2.0L 2004, in which such resource is not available. To implement this resource, the project uses an electronic engine management unit (also known as Electronic Control Unit - ECU) developed in 2013 by the Otto II project (PEREIRA, 2013). This ECU is responsible to control the engine of the respective vehicle, which allows the Cruise Control validation through a set of tests performed with the vehicle on an inertial dynamometer. However, prior to the Cruise Control design, this project focused on the ECU operation enhancement, in order to achieve the state of the art in electronic engine management units. For this goal, the project, during its first phase, performed several improvements on the control algorithms already existing in the firmware developed in 2013, such as idle speed control, electronic throttle valve control and engine starting control. At the same time, new features were fully implemented in firmware: torque control, closed loop air/fuel ratio control (lambda control), safety for the communication among ECU blocks, gear identification, support to OBD-II diagnostic, among others. In addition to the firmware development activities, the project, still in its first phase, developed a new software tool capable of monitoring several ECU parameters in real time, besides providing many functions, such as alternative board computer, an option to control the engine by simulating the throttle pedal, an option to change the idle speed and a function to automate the system identification test (task required for the Cruise Control design).
164

L’industrie des croisières au Québec et les impacts environnementaux sur le Saint-Laurent

Kingsbury, Antoine 03 1900 (has links)
No description available.
165

Cruise terminal

Fong, Wan-hang, Angela., 方蘊蘅. January 2000 (has links)
published_or_final_version / Architecture / Master / Master of Architecture
166

Conception & développement d'une plateforme en réalité virtuelle de pilotage de véhicules intelligents / Virtual reality platform design & development for intelligent vehicles control

Luo, Minzhi 21 September 2012 (has links)
Cette thèse est consacrée au domaine interdisciplinaire des Systèmes de Transport Intelligents et des technologies de Réalité Virtuelle. Elle se concentre sur l’amélioration des stratégies de commande des véhicules intelligents en tenant compte des impacts de l’environnement naturel ainsi que sur l’analyse de performance, la visualisation et la vérification de la validité des algorithmes de commande sur la plateforme de véhicules intelligents réalité virtuelle (IVVR).La plateforme IVVR comprend trois sous-systèmes : un sous-système de commande de véhicules intelligents, un sous-système de visualisation et un sous-système virtuel sans fil. Le synthétique environnement naturel a été modélisé et simulé pour la simulation et l’analyse de performance des stratégies de commande sous conditions environnementales complexes. Ensuite, les expérimentations concernant le trafic équipé du régulateur de vitesses adaptatives (ou coopérative) sont exécutés et ils montrent que les systèmes existants ont échoué à maintenir une espace inter-véhiculaire de sécurité lorsque les conditions d’environnement naturel sont défavorables. Dans ce cas, nous proposons un nouvel algorithme de commande appelé NECACC pour le contrôle longitudinal du véhicule en maintenant une espace inter-véhiculaire de sécurité et garantissant une capacité de circulation optimisée même dans des conditions environnementales complexes. Cet algorithme est ensuite simulé, vérifié et validé sur la plateforme IVVR. Enfin, les démonstrations de trafic virtuel effectuant des manœuvres communes de circulation contrôlés par les systèmes de commande intégrés proposées sont présentées sous diverse conditions environnementales / This thesis is dedicated to the interdisciplinary area of Intelligent Transportation Systems and Virtual Reality technologies. It focuses on the improvement of intelligent vehicles control strategies by considering the natural environment impacts as well as the visualization, the verification and performance analysis of proposed control algorithms on the proposed Intelligent Vehicles Virtual Reality (IVVR) platform.The IVVR platform includes three subsystems: Vehicle Intelligent Control Subsystem, Visualization Subsystem and Virtual Wireless Subsystem. For realizing the control strategy simulation and performance analysis under complex natural environment conditions, Synthetic Natural Environment has been modeled and simulated in this IVVR platform. Therefore, experiments of Adaptive Cruise Control (ACC) or Cooperative ACC system equipped traffic are executed and show that normal ACC/CACC system fails to keep a safe inter-vehicle space when the natural environment condition is variable or adverse especially in stiff conditions. For solving this problem, we propose a new control algorithm called NECACC (Natural Environment based CACC) for longitudinal vehicle control in maintaining a safe inter-vehicle distance as well as guaranteeing an appropriate traffic capacity even under complex environmental conditions. This algorithm is then simulated and verified in IVVR platform as a “proof of concept”. Finally, some virtual traffic demonstrations performing common traffic maneuvers are presented in IVVR platform under various environmental conditions. The vehicle platoon is controlled by proposed integrated control system and the safety can be ensured all the time
167

Mobilní app pro měření odstupu od předchozího vozidla v provozu / Mobile App for Measuring the Range from the Preceding Vehicle in Traffic

Henry, Andrii January 2015 (has links)
This master's thesis deals with development of mobile app for measuring the range from the preceding vehicle in traffic using visual-based methods. This paper describes implementation of computer vision algorithms of detection and tracing objects, detection of horizon on desktop and mobile devices. Also deals with visual-based range measuring without any other mechanisms. The output of the work is implemented detectors of vihicles and horizon using OpenCV library on the Windows platfom and draft of user inerface of a mobile phone aplication on the Android platform.
168

"Green Cheese" and "the Moon": Jimmy Carter, Ronald Reagan, and the Euromissiles

Griffith, Luke January 2018 (has links)
No description available.
169

Handoff of Advanced Driver Assistance Systems (ADAS) using a Driver-in-the-Loop Simulator and Model Predictive Control (MPC)

Wilkerson, Jaxon 01 December 2020 (has links)
No description available.
170

Safe Controller Design for Intelligent Transportation System Applications using Reachability Analysis

Park, Jaeyong 17 October 2013 (has links)
No description available.

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