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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.
11

Autonomous Vehicle Social Behavior for Highway Driving

Wei, Junqing 01 May 2017 (has links)
In recent years, autonomous driving has become an increasingly practical technology. With state-of-the-art computer and sensor engineering, autonomous vehicles may be produced and widely used for travel and logistics in the near future. They have great potential to reduce traffic accidents, improve transportation efficiency, and release people from driving tasks while commuting. Researchers have built autonomous vehicles that can drive on public roads and handle normal surrounding traffic and obstacles. However, in situations like lane changing and merging, the autonomous vehicle faces the challenge of performing smooth interaction with human-driven vehicles. To do this, autonomous vehicle intelligence still needs to be improved so that it can better understand and react to other human drivers on the road. In this thesis, we argue for the importance of implementing ”socially cooperative driving”, which is an integral part of everyday human driving, in autonomous vehicles. An intention-integrated Prediction- and Cost function-Based algorithm (iPCB) framework is proposed to enable an autonomous vehicles to perform cooperative social behaviors. We also propose a behavioral planning framework to enable the socially cooperative behaviors with the iPCB algorithm. The new architecture is implemented in an autonomous vehicle and can coordinate the existing Adaptive Cruise Control (ACC) and Lane Centering interface to perform socially cooperative behaviors. The algorithm has been tested in over 500 entrance ramp and lane change scenarios on public roads in multiple cities in the US and over 10; 000 in simulated case and statistical testing. Results show that the proposed algorithm and framework for autonomous vehicle improves the performance of autonomous lane change and entrance ramp handling. Compared with rule-based algorithms that were previously developed on an autonomous vehicle for these scenarios, over 95% of potentially unsafe situations are avoided.
12

Navigating Navigation : A Safety and Usability Evaluation of the Volvo P1 Navigation System

Lindgren, Anders January 2005 (has links)
<p>Navigation systems are today options provided by car manufacturers’ world wide and market predictions suggest that 25 percent of all cars produced by 2009 will have navigation systems installed. However, there are many human-interface issues concerning the use of these navigation systems. This thesis describes a study which evaluates and tests the safety and usability of the Volvo P1 navigation system and also contains suggestions on how the system and its controls should be designed to be safer and easier to use. This is done through heuristic evaluations and a Lane Change Test (LCT). The LCT is used to compare the level of driver distraction between the steering wheel control and remote control and also between common and advanced exercises in the system. Results from the study shows that there are no significant differences in distraction between using the steering wheel control or the remote control. The results also show that there are no significant differences in distraction between the common and advanced exercises. The results of the study are presented as a collection of design proposals that can be used to improve the system’s safety and usability.</p>
13

Vehicle Dynamics Testing in Advanced DrivingSimulators Using a Single Track Model

Thellman, Jonas January 2012 (has links)
The purpose of this work is to investigate if simple vehicle models are realisticand useful in simulator environment. These simple models have been parametrisedby the Department of Electrical Engineering at Linköping University and havebeen validated with good results. The models have been implemented in a simulatorenvironment and a simulator study was made with 24 participants. Eachtest person drove both slalom and double lane change manoeuvres with the simplemodels and with VTI’s advanced model. The test persons were able to successfullycomplete double lane changes for higher velocities with the linear tyre modelcompared to both the non-linear tyre model and the advanced model. The wholestudy shows that aggressive driving of a simple vehicle model with non-linear tyredynamics is perceived to be quite similar to an advanced model. It is noted significantdifferences between the simple models and the advanced model when drivingunder normal circumstances, e.g. lack of motion cueing in the simple model suchas pitch and roll.
14

Design and Implementation of Steering Vehicles System by Joystick

Lin, Yu-kun 13 July 2011 (has links)
The goal of this thesis is to design the steering vehicle system by joystick. The main function of the steering vehicle system is drivers can operate the joystick with electrical control to accomplish steering motion. In this paper , the main design framework of the steering vehicle system is divided into three stages of the experiment, vehicle architecture, vehicle dynamic simulation and vehicle test results . The overall system is modified Go-kart as a platform, develop a suitable joystick framework in the vehicle, and apply the encoder on the joystick, which transfer the control information into the position signal, to be the input command of steering motor control program. According to the steering by wire for brushless DC servo motor control strategy, the system control architecture achieve the goal by embedded-DSP. And to test double-lane change by Go-kart. Experimental results recorded by gyroscope can compare the steering situation of joystick with steering wheel.
15

Control and Management Strategy of Autonomous Vehicle Functions

Kim, Chang Won 2010 December 1900 (has links)
In this research, an autonomous vehicle function management methodology is studied. In accordance with the traffic situation, the decision making level chooses the optimal function that guarantees safety and minimizes fuel consumption while the control level is implemented via neuromorphic strategy based on the brain limbic system. To realize the decision making strategy, the Analytic Hierarchy Process (AHP) is used by considering driving safety, driving speed, and fuel efficiency as the objectives. According to the traffic situation and predefined driving mode, Lane Change Maneuver (LCM) and Adaptive Cruise Control (ACC) are chosen as the alternative functions in the AHP framework. The adaptive AHP is utilized to cope with dynamically changing traffic environment. The proposed adaptive AHP algorithm provides an optimal relative importance matrix that is essential to make decisions under a varying traffic situation and driving modes. The simulation results show that proposed autonomous vehicle function management structure produces optimal decisions that satisfy the driving preference. The stability of BLS based control is also investigated via Cell-to-Cell Mapping. In this research, autonomous vehicle functions such as Lane change maneuver and Adaptive cruise control are developed by means of BLS based control. The simulation results considered various traffic situations that an autonomous vehicle can encounter. To demonstrate the suggested control method Cell-to-Cell Mapping is utilized. Subsequently, the autonomous vehicle function management strategy is developed by Applying AHP and an adaptive AHP strategy is developed to cope with various traffic situations and driving modes. The suggested method is verified numerical simulations.
16

Navigating Navigation : A Safety and Usability Evaluation of the Volvo P1 Navigation System

Lindgren, Anders January 2005 (has links)
Navigation systems are today options provided by car manufacturers’ world wide and market predictions suggest that 25 percent of all cars produced by 2009 will have navigation systems installed. However, there are many human-interface issues concerning the use of these navigation systems. This thesis describes a study which evaluates and tests the safety and usability of the Volvo P1 navigation system and also contains suggestions on how the system and its controls should be designed to be safer and easier to use. This is done through heuristic evaluations and a Lane Change Test (LCT). The LCT is used to compare the level of driver distraction between the steering wheel control and remote control and also between common and advanced exercises in the system. Results from the study shows that there are no significant differences in distraction between using the steering wheel control or the remote control. The results also show that there are no significant differences in distraction between the common and advanced exercises. The results of the study are presented as a collection of design proposals that can be used to improve the system’s safety and usability.
17

Modeling Slow Lead Vehicle Lane Changing

Olsen, Erik Charles Buck 09 December 2003 (has links)
Driving field experiment data were used to investigate lane changes in which a slow lead vehicle was present to: 1) characterize lane changes, 2) develop predictive models, 3) provide collision avoidance system (CAS) design guidelines. A total of 3,227 slow lead vehicle lane changes over 23,949 miles were completed by sixteen commuters. Two instrumented vehicles, a sedan and an SUV, were outfitted with video, sensor, and radar data systems that collected data in an unobtrusive manner. Results indicate that 37.2% of lane changes are slow lead vehicle lane changes, with a mean completion time of 6.3 s; most slow lead vehicle lane changes are leftward, rated low in urgency and severity. A stratified sample of 120 lane changes was selected to include a range of maneuvers. On the interstate, lane changes are performed less often, <i>t</i>(30) = 2.83, <i>p</i> = 0.008, with lower urgency ratings, <i>F</i>(1, 31) = 5.24, <i>p</i> = 0.05, as compared to highway lane changes, as interstates are designed for smooth flow. Drivers who usually drive sedans are more likely to make lane changes than drivers of SUVs, <i>X</i> ²⁺(1)= 99.6247, <i>p</i> < 0.0001, suggesting that driving style is maintained regardless of which experimental vehicle is driven. Turn signals are used 64% of the time but some drivers signal after the lane change starts. Of cases in which signals are not used, 70% of them are made with other vehicles nearby. Eyeglance analysis revealed that the forward view, rearview mirror, and left mirror are the most likely glance locations. There are also distinct eyeglance patterns for lane changing and baseline driving. Recommendations are to use forward view or mirror-based visual displays to indicate presence detection, and auditory displays for imminent warnings. The "vehicle + signal" logistic regression model is best overall since it takes advantage of the distance to the front and rear adjacent vehicle, forward time-to-collision (TTC), and turn signal activation. The use of additional regressors would also improve the model. Five design guidelines are included to aid in the development of CAS that are useable, safe, and integrated with other systems, given testing and development. / Ph. D.
18

Observation empirique et modélisation des discontinuités du réseau autoroutier : vers l’estimation des capacités / Empiric observation and modelling of the highway network discontinuities : toward capacity estimation

Marczak, Florian 27 October 2014 (has links)
La congestion routière est le résultat d’un excès de la demande sur l’offre. Sur le réseau autoroutier en particulier, la congestion apparaît soit en section courante, soit au niveau des bretelles d’accès, des bretelles de sortie ou des zones d’entrecroisement qui sont généralement appelées les discontinuités ou nœuds du réseau routier. Les objectif de la thèse sont (i) d'apporter des éclairages sur la phénoménologie du trafic au droit des discontinuités du réseau autoroutier et (ii) de proposer des modèles macroscopiques pour en prédire le fonctionnement et évaluer des stratégies d'optimisation de l'écoulement du flux. Contrairement aux modèles existants, les modèles proposés dans cette thèse prennent en compte les phénomènes physiques du trafic en intégrant explicitement les comportements individuels des usagers. Après avoir présenté les outils méthodologiques et expérimentaux mobilisés, la thèse propose une analyse empirique des changements de voie à partir de données individuelles de trajectoires. Sur la base des résultats empiriques, la thèse présente ensuite les modèles analytiques développés qui sont utilisés dans une dernière partie pour proposer des stratégies d'optimisation de l'écoulement du flux du trafic. / The congestion occurs when the demand is higher than the supply. On the highway network, the congestion forms on the diverges, the merges and the weaving section which are generally named the discontinuities of the network. The thesis aims at (i) investigating the traffic phenomenology at the discontinuities of the highway network and (ii) developing macroscopic traffic flow model to forecast their operation and evaluate traffic regulations. Those models will explicitly integrate the drivers' microscopic behaviors. The thesis presents first the methodological and experimental tools. Then, it proposes an empirical analysis of the lane-changes at two merges and one weaving sections. The thesis describes the analytical models while it ends with operational applications of those models.
19

Adjust your view! Wing-mirror settings influence distance estimations and lane-change decisions

Böffel, Christian, Müsseler, Jochen 16 May 2019 (has links)
To perform lane-change maneuvers safely, sufficient distance to the subsequent traffic is required. In the present study distance estimations to the subsequent vehicle (Experiment 1) and lane-change decisions (Experiment 2) were gathered in dependency of left wing-mirror settings: Different vertical settings resulted in low and high vehicle positions with less or more pavement visible in the mirror. Additionally, the visibility or non-visibility of the observer's rear door was varied. Findings indicated that a low vertical position of the following vehicle in the mirror and a visible rear door lead to shorter distance estimations and more cautious lane-change decisions than a high vertical position and a non-visible rear door. Consequently, wing-mirror settings are important for traffic safety.
20

Návrh a ověření funkčnosti systému směrového řízení vozidla / Design and evaluation of vehicle steering controller

Margetaj, Martin January 2019 (has links)
V této práci je prezentován a popsán FlexRay komunikační protokol se sběrnicí. Je představeno několik matematických modelů vozidel pro simulaci a pro vývoj řídících systémů. Dále je popsána tvorba signálové brány pro testovací vozidlo. Software pro úpravu signálu je implementován a odzkoušen v testovacím vozidle. Matematick0 modely byli parametrizovány aby odpovídali skutečnému vozidlu. Vyvinuté řídící systémy pro ovládání vozidla skrze losí test byli implementovány do automobilu a jejich vlastnosti byli otestovány. Závěrem jsou prezentovány výsledky testů jednotlivých řídících systémů.

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