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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.
61

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).
62

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
63

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.
64

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.
65

Safe Controller Design for Intelligent Transportation System Applications using Reachability Analysis

Park, Jaeyong 17 October 2013 (has links)
No description available.
66

Modelling and Simulation for Evaluation of Cooperative Intelligent Transport System Functions

Aramrattana, Maytheewat January 2016 (has links)
Future vehicles are expected to be equipped with wireless communication technology, that enables them to be “connected” to each others and road infrastructures. Complementing current autonomous vehicles and automated driving systems, the wireless communication allows the vehicles to interact, cooperate, and be aware of its surroundings beyond their own sensors’ range. Such sys- tems are often referred to as Cooperative Intelligent Transport Systems (C-ITS), which aims to provide extra safety, efficiency, and sustainability to transporta- tion systems. Several C-ITS applications are under development and will require thorough testing and evaluation before their deployment in the real-world. C- ITS depend on several sub-systems, which increase their complexity, and makes them difficult to evaluate. Simulations are often used to evaluate many different automotive applications, including C-ITS. Although they have been used extensively, simulation tools dedicated to determine all aspects of C-ITS are rare, especially human factors aspects, which are often ignored. The majority of the simulation tools for C-ITS rely heavily on different combinations of network and traffic simulators. The human factors issues have been covered in only a few C-ITS simulation tools, that involve a driving simulator. Therefore, in this thesis, a C-ITS simulation framework that combines driving, network, and traffic simulators is presented. The simulation framework is able to evaluate C-ITS applications from three perspectives; a) human driver; b) wireless communication; and c) traffic systems. Cooperative Adaptive Cruise Control (CACC) and its applications are chosen as the first set of C-ITS functions to be evaluated. Example scenarios from CACC and platoon merging applications are presented, and used as test cases for the simulation framework, as well as to elaborate potential usages of it. Moreover, approaches, results, and challenges from composing the simulation framework are presented and discussed. The results shows the usefulness of the proposed simulation framework.
67

Robust Safe Control for Automated Driving Systems With Perception Uncertainties / Robust Säker Styrning för Automatiserade Körsystem med Avseende på Perceptions Osäkerheter

Feng Yu, Yan January 2022 (has links)
Autonomous Driving Systems (ADS), a subcategory of Cyber-Physical Systems (CPS) are becoming increasingly popular with ubiquitous deployment. They provide advanced operational functions for perception and control, but this also raises the question of their safety capability. Such questions include if the vehicle can stay within its lane, keep a safe distance from the leading vehicle, or avoid obstacles, especially under the presence of uncertainties. In this master thesis, the operational safety of ADS will be addressed, more specifically on the Adaptive Cruise Control (ACC) system by modeling an optimal control problem based on Control Barrier Function (CBF) unified with Model Predictive Control (MPC). The corresponding optimal control problem is robust against measurement uncertainties for an Autonomous Vehicle (AV) driving on a highway, where the measurement uncertainties will represent the common faults in the perception system of the AV. A Kalman Filter (KF) is also added to the system to investigate the performance difference. The resulting framework is implemented and evaluated on a simulation scenario created in the open-source autonomous driving simulator CARLA. Simulations show that MPC-CBF is indeed robust against measurement uncertainties for well-selected horizon and slack variable values. The simulations also show that adding a KF improves the overall performance. The higher the horizon, the more confident the system becomes as the distance to the leading vehicle decreases. However, this may cause infeasibility where there are no solutions to the optimal control problem during sudden braking as the AV cannot brake fast enough before it crashes. Meanwhile, the smaller the slack variable, the more restrictive becomes CBF where it impacts more on the control input than desired which could also cause infeasibility. The results of this thesis will help to facilitate safety-critical CPS development to be deployed in real-world applications. / Autonoma körsystem (ADS), som är en del av cyberfysiska system (CPS), har blivit alltmer populär med allestädes närvarande användning. Det bidra med avancerade operativa funktioner för perception och styrning, men samtidig väcker detta också frågan om dess säkerhetsförmåga. Sådana frågor inkluderar om fordonet kan hålla sig inom sitt körfält, om det kan hålla ett säkert avstånd till det ledande fordonet eller om det kan undvika hinder, speciellt under osäkerheter hos systemet. I detta examensarbete kommer driftsäkerheten hos ADS att behandlas, mer specifik på adaptiv farthållare (ACC) genom att modellera ett optimalt kontrollproblem baserat på kontrollbarriärfunktion (CBF) förenat med modellförutsägande styrning (MPC). Motsvarande optimalt kontrollproblem är robust mot mätosäkerheter för ett autonomt fordon som kör på en motorväg, där mätosäkerheterna representerar vanliga fel i AV:s perceptionssystem. Ett Kalmanfilter (KF) läggs också till i systemet för att undersöka skillnaden i prestanda. Det resulterande ramverket implementeras och utvärderas på ett simuleringsscenario som skapats i den öppna källkodssimulatorn för autonom körning CARLA. Simulationer visar att MPC-CBF är robust mot mätosäkerheter för väl valda värden för horisont och slackvariabler. Det visar också att systemets prestanda förbättrats ännu mer om ett KF läggs till. Ju större horisont, desto mer självsäkert blir systemet när avståndet till det ledande fordonet minskar. Detta kan dock leda till att det inte finns några lösningar på det optimala kontrollproblemet vid plötslig inbromsning, eftersom fordonet inte hinner bromsa tillräckligt snabbt innan det kraschar. Ju mindre slackvariabeln är, desto mer restriktiv blir CBF som påverkar styrningen mer än vad som är önskvärt vilket också kan leda till olösbart optimalt kontrollproblem. Resultatet från detta examensarbete bär syftet att gynna utvecklingen av säkerhetkritisk CPS som ska användas i praktiska tillämpningar.
68

Performance Assessment of a 77 GHz Automotive Radar for Various Obstacle Avoidance Application

Komarabathuni, Ravi V. 26 July 2011 (has links)
No description available.
69

Nutzen und Grenzen von 3D-Anzeigen in Fahrzeugen

Krüger, Karen 04 June 2008 (has links)
In dieser Arbeit wurden nutzbringende Anwendungsmöglichkeiten für monoskopische und (auto)stereoskopische 3D-Anzeigen in Fahrzeugen theoretisch hergeleitet und empirisch überprüft. Zur Ableitung der Hypothesen wurde für jede Teilaufgabe anhand eines Fragenkatalogs zu den Vor- und Nachteilen von 3D-Anzeigen untersucht, inwieweit deren Bearbeitung davon profitiert, dass Informationen räumlich abgebildet werden. Die erwiesenen 3D-Vorteile wurden zu fünf Kategorien zusammengefasst: Integration, räumliche Kompatibilität, Aufmerksamkeitslenkung, Bildhaftigkeit und Attraktivität. Da der wesentliche 3D-Vorteil für Anzeigen in Fahrzeugen in einer räumlich kompatiblen Informationsdarstellung aus der Fahrerperspektive gesehen wurde, lag der Schwerpunkt der empirischen Arbeit auf 3D-Anzeigen für Fahrerassistenzsysteme (FAS). Am Beispiel einer 3D-Anzeige des Abstandsregeltempomaten (ART) wurde nachgewiesen, dass die Vorteile von 3D-Anzeigen für FAS in einer Erhöhung der Attraktivität und Akzeptanz sowie in einer Verbesserung des unmittelbaren Verständnisses im Vergleich zu 2D-Anzeigen liegen. Gleichzeitig wurden mit optimal gestalteten 3D-Anzeigen keine Nachteile in der Wahrnehmungssicherheit und Ablenkungswirkung festgestellt. Anhand der Literaturanalyse und der empirischen Ergebnisse wurden Gestaltungshinweise für 3D-Anzeigen in Fahrzeugen formuliert. Der erwartete 3D-Vorteil einer kompatiblen Darstellung stellte sich bei einer konstanten Anordnung der Informationen nicht ein, bleibt aber für Aufgaben mit einem kontinuierlichen Abgleich (z.B. Navigation) zu überprüfen. Die stereoskopische Darbietung erbrachte keinen besonderen Nutzen. Das fahrzeugtaugliche ASD erhöhte sogar die Reaktionszeiten. Insgesamt sprechen die Ergebnisse für eine gezielte Verwendung bildhafter monoskopischer 3D-Anzeigen für FAS und ausgewählte räumliche Funktionen, welche sich anhand von Begriffen und abstrakten Symbolen nur schwer erläutern lassen. / This thesis consists of the theoretical deduction and empirical evaluation of useful applications for monoscopic and (auto)stereoscopic 3D-displays in vehicles. For deducting hypotheses concerning the benefits and limits of 3D-displays, each subtask was tested for its potential benefits from a 3D-information presentation using a catalogue of confirmed advantages and disadvantages of 3D-displays. The proven 3D-advantages were summarized in five categories: integration, spatial compatibility, direction of attention, concreteness and attractiveness. Because it was presumed, that 3D-displays in vehicles are especially favorable for representing information about the vehicle surrounding in a 3D-perspective compatible to the drivers view, the empirical part was mainly focused on the application of 3D-displays for driver assistance systems. Using a 3D-display for adaptive cruise control (ACC), a general increase of attractiveness, acceptance and immediate comprehension for 3D-displays in comparison to conventional 2D-displays was confirmed. Simultaneously, well designed 3D-displays did not compromise perceptional safety and driver distraction. Design guidelines for 3D-displays in vehicles were concluded from the evaluation results and from literature analysis. Even though the expected 3D-benefit of spatially compatible information displays from the driver’s perspective was not confirmed for driver assistance systems like ACC with a constant layout of information, it still remains to be tested for continuous matching tasks like navigational checking in cars. The stereoscopic presentation of 3D-displays did not show advantages. On the contrary, an in-vehicle ASD even increased reaction times. In summery, the results suggest a distinctive application of well designed concrete and monoscopic 3D-displays for driver assistance systems and selected spatial functions which are difficult to explain using abstract notions or symbols.
70

Channel measurement and communication module for the Grand Cooperative Driving Challenge

Bergh, Fredrik, Andersson, Johan January 2011 (has links)
Vehicular ad hoc networks (VANETs) are a hot topic in the intelligent transport system (ITS) area. The introduction of wireless communications between vehicles will enable many useful applications to enhance road traffic safety as well to increase efficiency. The standardization of IEEE 802.11p, being an amendment to IEEE 802.11 intended for VANETS, faces many challenges. In Europe a 30 MHz spectrum at 5.9 GHz have been dedicated for ITS and this spectrum has to be used to its full potential. For this reason this thesis compares a 20 MHz wide frequency channel with a 10 MHz wide through measurements using 802.11p hardware. The measurements were conducted on a highway with relative speeds of up to 240 km/h. The results from these initial measurements show that a 20 MHz channel does not perform worse than a 10 MHz channel despite the high relative speeds and large metal signs scattering the signals. What enabled this thesis to do the measurements was Halmstad University‟s participation in the Grand Cooperative Driving Challenge (GCDC) 2011. In GCDC nine teams mostly from Europe competed in having the vehicle that had the best behaviour in a platoon of vehicles using cooperative adaptive cruise control (CACC), the CACC algorithm controlled the vehicles‟ acceleration and breaking autonomously based on in-vehicle sensors and communicated messages between the vehicles in the platoon using 802.11p. This thesis implemented the communication part of Halmstad University‟s vehicle. The challenge was held in Helmond, Holland, May 14-15, 2011. Halmstad University‟s team finished in second place. / CoAct

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