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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

Prediction and Prevention of Simulator Sickness: An Examination of Individual Differences, Participant Behaviours, and Controlled Interventions

Reed Jones, James 23 December 2011 (has links)
Fixed-base driving simulators are commonplace in research and training. Simulators provide safe and controlled environments to train users on vehicle and device operation, to evaluate the safety of devices and controls, and to conduct research on driving and driving behaviours. One drawback to simulators is simulator sickness. As with motion sickness, simulator sickness can cause nausea, but additionally it has symptoms such as headache and eyestrain. Simulator sickness is a problem for multiple reasons: it can skew experimental results, it can waste participants’ and experimenter’s time, and it can limit testable populations. In addition, participants may modify their behaviour to avoid sickness, affecting experimental results or impeding learning. While sickness can reduce over multiple exposures, it is not known if any observable behaviours accompany these reductions. It is also not known why there are such marked individual differences in susceptibility. To test for behaviours that could be responsible for reducing sickness, I examined participants across two sessions in a fixed-base driving simulator. I found that gaze behaviour (eye and head movements) changed along with sickness. To determine the cause for this finding I instructed participants (pre-drive) to fixate their gaze during the curves of a simulated drive. This gaze modification was effective in reducing sickness during a first-time experience in the simulator, supporting a causal link. Next, I attempted to replace the missing vestibular input in a fixed-base simulator, so that the visual and vestibular perceptions of motion matched. This experiment showed that by providing vestibular stimulation appropriate or opposite of what would occur in the real world reduced sickness. This provided support for the theory that distracting stimulation (electrical in this case) could reduce attention to visual motion cues and therefore reduce conflict, a novel finding for simulator sickness research. Finally, I tested for any correlations between individual differences and sickness. I found that history of motion sickness and current illness both correlated with sickness, potentially useful as a pre-screening tool. In addition, driving behaviours such as speed, braking, and acceleration all correlated with sickness, showing that how a person behaves in a simulation could also contribute to sickness. / CFI, OGS, Auto21
12

Effect of different alcohol levels on take-over performance in conditionally automated driving

Wiedemann, Katharina, Naujoks, Frederik, Wörle, Johanna, Kenntner-Mabiala, Ramona, Kaussner, Yvonne, Neukum, Alexandra 30 September 2020 (has links)
Automated driving systems are getting pushed into the consumer market, with varying degrees of automation. Most often the driver’s task will consist of being available as a fall-back level when the automation reaches its limits. These so-called take-over situations have attracted a great body of research, focusing on various human factors aspects (e.g., sleepiness) that could undermine the safety of control transitions between automated and manual driving. However, a major source of accidents in manual driving, alcohol consumption, has been a non-issue so far, although a false understanding of the driver’s responsibility (i.e., being available as a fallback level) might promote driving under its influence. In this experiment, N = 36 drivers were exposed to different levels of blood alcohol concentrations (BACs: placebo vs. 0.05% vs. 0.08%) in a high fidelity driving simulator, and the effect on take-over time and quality was assessed. The results point out that a 0.08% BAC increases the time needed to re-engage in the driving task and impairs several aspects of longitudinal and lateral vehicle control, whereas 0.05% BAC did only go along with descriptive impairments in fewer parameters.
13

Effet des messages de sécurité routière sur la détection des cyclistes par les automobilistes dans un environnement dynamique : implication des processus attentionnels et émotionnels / Effect of road safety messages on cyclist detection by motorists in dynamic environments : involvement of attentional and emotional processes

Lafont, Alex 30 November 2018 (has links)
Le principal objectif de cette thèse est de mieux comprendre comment un message de prévention peut moduler les capacités de détection d'usagers vulnérables chez un automobiliste. Un message de prévention délivre à la fois une information sur la vulnérabilité de certains usagers mais peut également générer des émotions chez la personne qui y est exposée. Cette thèse s'intéresse donc d'une part à comment l' émotion seule, mais également l'information sur la vulnérabilité de certains usagers de la route, peuvent impacter les capacités de détection des usagers vulnérables. Nous porterons une attention particulière aux cyclistes, population pour laquelle, à notre connaissance, peu de travaux existent à ce sujet. Par ailleurs, étant donné le focus porté sur les émotions dans le cadre de cette thèse, l'un des objectifs secondaire de cette thèse sera de s'intéresser à des signatures physiologiques particulières de certaines émotions / The aim of the present project is to provide a better understanding of how safety messages can control drivers' vulnerable road user detection abilities. Safety messages provide both vulnerability information and elicit emotion with persons that are exposed to it. This thesis deals with how vulnerability information and emotions respectively affect vulnerable road user detection performances. A special focus was placed on cyclists because of the lack of studies that address cyclist detetcion issues. The project also focused on physiology, especially emotion identification through physiological patterns.
14

ADAS : A simulation study comparing two safety improving Advanced Driver Assistance Systems

Mattsson, David January 2012 (has links)
Driving is a high-risk adventure which many enjoy on a daily basis. The driving task is highly complex, ever-changing, and one which requires continuous attention and rapid decision making. It is a task that is not without risk, where the cost to reach the desired destination can be too great – your life could be at stake. Driving is not without incidents. Rear-end collision is a common problem in the Swedish traffic environment, with over 100 police-reported individual incidents per year. The amount of rear-end collisions can be hypothetically reduced by introducing new technology in the driver’s vehicle, technology which attempts to improve the driver’s safety driving. This technology is called Advanced Driver Assistance Systems – ADAS. In this study two ADAS were evaluated in a driving simulator study: An Adaptive Cruise Control (ACC) which operates on both hazardous and non-hazardous events, and a Collision Warning System (CWS) which operates solely on non-hazardous events. Both of these ADAS function to guard against risky driving and are based on the assumption that drivers will not act in such a manner that they would willingly reduce the effectiveness of the system. A within-subjects simulation study was conducted where participants drove under three conditions: 1) with an adaptive cruise controller, 2) a frontal rear-end collision warning system ADAS, and 3) unaided, in order to investigate differences between the three driving conditions. Particular focus was on whether the two ADAS improved driving safety. The study results indicate that driving enhanced by the two ADAS made the participating drivers drive less safely.
15

Development of models for detection of automobile driver impairment

Dingus, Thomas A. 15 November 2013 (has links)
Two of the leading causes of automobile accidents are driver impairment due to alcohol and drowsiness. Apparently, a relatively large percentage of these accidents occur because drivers are unaware of the degree to which they are impaired due to these sources. The purpose of this research was to develop models which could detect driver impairment due to alcohol, drowsiness, or the combination of alcohol and drowsiness, and which could be practically implemented in an automobile. Such detection models, if successfully implemented in conjunction with a system to warn an impaired driver of his or her condition, could potentially save hundreds of lives each year. Six driver-subjects operated a computer controlled driving simulator during each of four conditions. The four conditions consisted of a control condition, an alcohol condition, a sleep-deprived condition, and a combination alcohol and sleep-deprived condition. Moderate levels of alcohol and sleep deprivation were used for this study. Nineteen performance and behavioral measures were collected during this study. Each measure was evaluated singly and in combination with other measures to determine potential value for detection of driver impairment. Detection models were then formulated using the most promising detection measures. The results indicated that a useful on-board drowsiness impairment detection device is possible and practical for highway driving. This device would also, in all likelihood, provide useful detection information regardless of whether low to moderate amounts of alcohol were present in a drowsy driver. The results also showed that on-board alcohol impairment detection may be possible at moderate to high BAC. / Master of Science
16

Measuring Complexity of Built Environments : The impact of traffic lights and load of traffic levels on how drivers perceive stress

Papamarkos, Periandros January 2020 (has links)
To understand which factors affect the perception of stress while driving is interesting since it would help us to get closer to comprehending how the street network design can avoid putting stress on the drivers. Earlier research has measured drivers’ perception of safety under different street conditions by using video clips of real street environments. This study, that is carried out in cooperation with ITRL and it forms part of the MERGEN project, aims to introduce HCI techniques in order to prove that these techniques can bring valuable and credible results when substituting the conventional means of carrying out experiments. The study focuses on how the level of car traffic and the presence or not of traffic signs and lights affect how the drivers’ perceive stress emotion. To extract relevant information, a perceptual experiment was conducted in which 29 subjects were exposed to stimuli that represented four different virtual street scenarios. Each scenario comprised a unique case that combined the two factors under examination. In order to measure the levels of the perceived stress, the subjects of the experiment were asked to answer questions on how they perceive the following four aspects: confidence, comfort, route information and manageability of traffic load. It was concluded that the presence of traffic signs and automated traffic lights has a big impact on every aspect that was examined since a significant difference on the responses given was measured. It was also concluded that the level of car traffic does not play a very significant role when it alters in street scenarios where traffic signs and traffic lights are present. Nevertheless, the level of car traffic becomes a factor on how drivers perceive stress when the street scenario does not include presence of traffic signs and lights. The use of HCI techniques with the goal to extract information on how drivers perceive emotions managed to give back descriptive results, something that can enhance the use of this kind of methods in the evaluation of not only street network designs but any Built Environment design in general. The study is conducted using virtual scenarios but is meant to help better understand emotions in real situations. / Att förstå vilka faktorer som påverkar uppfattningen av stress under körning är intressant eftersom det skulle hjälpa oss att begripa hur gatunätets design kan undvika att sätta stress på förarna. Tidigare forskning har mätt förarnas uppfattning om säkerhet under olika gatuförhållanden genom att använda videoklipp från verkliga gatumiljöer. Denna studie, som genomförs i samarbete med ITRL och ingår i MERGEN-projektet, syftar till att införa HCI-tekniker för att bevisa att dessa tekniker kan ge värdefulla och trovärdiga resultat när de ersätter konventionella metoder för att genomföra experiment. Studien fokuserar på hur nivån på biltrafik och närvaro av trafikskyltar och ljus påverkar hur förarna uppfattar stresskänslor. För att extrahera relevant information genomfördes ett perceptuellt experiment där 29 personer utsattes för stimuli som representerade fyra olika virtuella gatuscenarier. Varje scenario bestod av ett unikt fall som kombinerade de två faktorer som undersöktes. För att mäta nivåerna av den upplevda stressen ombads försökspersonerna att svara på frågor om hur de uppfattar de följande fyra aspekterna: förtroende, komfort, ruttinformation och hanterbarhet av trafikbelastningen. Man drog slutsatsen att närvaron av trafikskyltar och automatiserade trafikljus har stor inverkan på varje aspekt som undersöktes eftersom en signifikant skillnad i de givna svaren uppmättes. Man drog också slutsatsen att biltrafiknivån inte spelar en så viktig roll när den förändras i gatuscenarier där trafikskyltar och trafikljus finns. Ändå blir biltrafiknivån en faktor för hur förare upplever stress när gatuscenariot inte inkluderar närvaron av trafikskyltar och ljus. Användningen av HCI-tekniker i syfte att extrahera information om hur förare uppfattar känslor lyckades ge tillbaka beskrivande resultat, något som kan förbättra användningen av denna typ av metoder vid utvärderingen av inte bara gatunätdesign utan alla byggnadsmiljöer generellt. Studien genomförs med virtuella scenarier men är tänkt att hjälpa till att bättre förstå känslor i verkliga situationer.
17

Integrated Energy Management and Autonomous Driving System: A Driving Simulation Study

Bruck, Lucas Ribeiro January 2022 (has links)
In searching for more efficient vehicles with lower carbon emissions, researchers have invested enormous time and resources in designing new materials, components, systems, and control methods. The result is not only an immense volume of publications and patents but also a true electrification revolution in the transportation sector. Although the advancements are remarkable, much is still to be developed. Energy management systems are often designed to fulfil drive cycles that represent just a fraction of the actual use of the vehicles, disregarding essential factors such as driving conditions that may vary in real life. Furthermore, control algorithms should not ignore one of the most relevant driving aspects, comfort. Driving should be a pleasant activity since we spend much time of our lives performing this task. This research proposes a novel algorithm for managing energy consumption in electrified vehicles, the regen-based equivalent consumption minimization strategy (R-ECMS). Its suitability for solving the power-split problem is evaluated. Experiments emulating labelling schedules are conducted considering an example application. Robustness to different drive cycles and flexibility of the algorithm to various modes of operation are assessed. Furthermore, the method is integrated into an autonomous longitudinal control. The function leverages vehicle dynamics and journey mapping to assure energy efficiency and adequate drivability. Finally, the tests are conducted using human-driven cycles leveraging driving simulation technology. That allows for including driver subjective feelings in the design and assessing the algorithm's performance in realistic driving conditions. / Thesis / Doctor of Philosophy (PhD)
18

La perception des accélérations latérales en simulateur de conduite : étude de l'intégration multi-sensorielle pour l'amélioration des performances de simulation / Perception of lateral acceleration in driving simulator Study of multisensory integration for improvement of simulation performances : study of multisensory integration for improvement of simulation performances

Savona, Florian 06 December 2016 (has links)
Un simulateur de conduite dynamique est un outil permettant, entre autres, d’étudier les processus d’intégration multi-sensorielle pour la perception du mouvement et la production du comportement de conduite. Néanmoins, les limitations mécaniques des simulateurs, qui imposent des stratégies dynamiques pour simuler le réel, peuvent avoir un impact défavorable sur la perception et le comportement du conducteur. Cette problématique est particulièrement vraie pour la prise de virages qui demeure une situation difficile à reproduire de façon réaliste notamment à cause des variations importantes d’accélérations latérales. Dans ce contexte, cette thèse présente des travaux de recherches permettant de mieux comprendre les processus d’intégration multi-sensorielle (rôle des informations inertielles et visuelles) pour la perception du mouvement en virages et de caractériser l’évolution d’un percept en fonction des conditions de simulation.En conclusion, il a été démontré que la perception des accélérations latérales est basée sur des processus non-linéaires. Le rôle des informations visuelles et inertielles semble donc dépendre des individus et du contexte (notamment du niveau des accélérations latérales) dans lequel ces stimulations sont produites. Sur la base de l’ensemble de ces résultats, des nouvelles pistes d’amélioration du simulateur dynamique SHERPA² de PSA sont proposées. Il est préconisé notamment d’employer un gain du mouvement latéral dégressif avec l’augmentation du niveau d’accélération latérale. / A dynamic driving simulator is a tool, among others, allowing the study of multisensory integration for motion perception and production of driving behavior. Nevertheless, the mechanical limitations of the simulators which impose dynamic strategies to simulate the real can have an adverse negative impact on the driver perception and its behavior. This issue is particularly true for cornering which remains a difficult situation to reproduce in a realistic way, because of massive lateral accelerations variations. In this context, this thesis presents research works allowing to understand the processes of multisensory integration (role of inertial and visual information) for the motion perception in cornering and to characterize the evolution of a percept as a function of simulation conditions.In conclusion, it has been demonstrated that the perception of lateral accelerations is based on non-linear processes. The roles of visual and inertial information seem to depend on the individuals and on the context (notably the level of lateral accelerations) in which these stimulations are produced. Base on of the overall results, new ways for improvement of the dynamic driving simulator SHERPA2 are proposed. It is notably preconized to employ a lateral motion gain digressive with the increase of lateral acceleration.
19

Etude des lois de commande de la plateforme de simulation de conduite et influence sur le mal de simulateur / Study of control command of dynamic platform for driving simulation and influence on simulator sickness

Aykent, Baris 16 December 2013 (has links)
La simulation de conduite est fortement utilisée dans la recherche et le développement pour l'industrie automobile. Les simulateurs de conduite sont utilisés pour évaluer les prototypes véhicules pour la dynamique du véhicule et les systèmes d'aide à la conduite. Cependant, l'utilisation des simulateurs de conduite induit une problématique scientifique qui peut limiter son développement. En raison de son principe même, le simulateur de conduite ne restitue pas des mouvements du véhicule à l'échelle 1. Ce verrou cause des phénomènes de mal du simulateur qu'il est important d'étudier.Cette thèse propose d'étudier des méthodes et outils à mettre en œuvre dans les simulateurs de conduite statique ou dynamique. De cette mise en œuvre, des études sur le mal du simulateur sont menées grâce à des mesures objectives (via un capteur de suivi de mouvement, plate-forme de stabilité du corps, électromyographie) et subjectives (par l'intermédiaire de questionnaires). Des solutions algorithmiques et matérielles sont proposées et évaluées dans le contexte de la simulation de conduite.Les approches proposées dans cette thèse pour réduire le mal du simulateur sont:- Elaborer et évaluer les algorithmes de contrôle de la plate-forme mobile hexapode: sept algorithmes différents sont mis en œuvre.- Mesurer les effets liés au mal de simulateur sur les sujets aux niveaux vestibulaire, neuromusculaire et posturale.- Evaluer l'influence de l'implication des sujets sur le mal de simulateur (conducteurs et passagers). / Simulation has been intensively involved nowadays in research and development for automotive industry. Driving simulators are one of those simulation techniques which are used to evaluate the prototypes for the vehicle dynamics and driving assistance systems. However with the driving simulator, there is a lock associated with its use. Because representing a permanent scenario as scale 1 is quite difficult. Because of that difficulty, motion/simulator sickness is an inevitably important topic to study.This thesis proposes to explore methods and tools to implement in static or dynamic simulators. In this implementation, studies of simulator sickness are conducted with objective measures (via a motion tracking sensor, platform for body stability, electromyography) and subjective (through questionnaires). These algorithmic or hardware solutions studies should be defined and applied at simulators. The proposed approaches to reduce or avoid simulator sickness in this thesis are:- Building control algorithms of motion hexapod platform: seven different algorithms are implemented.- Measuring the effects of inertia on subjects at vestibular, neuromuscular and postural levels.- Assessing the involvement of subjects (drivers and passengers).
20

Complexité des situations, expérience, tension et vigilance : quels impacts sur la charge de travail et les performances de jeunes conducteurs ? / Situations complexity, experience, tension and vigilance : which impact on workload and performance of young drivers?

Paxion, Julie 05 December 2014 (has links)
L'objectif de cette thèse est d'identifier les liens entre les facteurs accidentogènes chez les jeunes conducteurs, en analysant les effets de la complexité de la situation et de l'expérience de conduite sur la charge de travail, la tension, la vigilance et les performances. L'hypothèse générale est que les situations coûteuses, i.e. simples et très complexes, ainsi que le manque d'expérience peuvent mener à une forte dépense énergétique. Ainsi, un haut niveau de tension et un faible niveau de vigilance peuvent provoquer des dégradations de performances à travers la hausse de la charge de travail, caractérisant une surcharge du conducteur. Ceci devrait s'observer plus précocement pour les novices ayant suivi un Apprentissage Traditionnel (AT), puis pour ceux ayant suivi un Apprentissage Anticipé de la Conduite (AAC), puis pour les conducteurs arrivant à la fin du permis probatoire, et enfin pour les plus expérimentés. Une première expérimentation menée sur des données subjectives a confirmé les liens entre les niveaux de charge de travail, de tension et de vigilance en fonction de la complexité de la situation. Une seconde expérimentation menée sur des données subjectives et physiologiques a également confirmé les liens entre les niveaux de charge de travail, de tension et de vigilance, avec une sous-estimation du niveau physiologique par les novices AT. Les résultats établissant les liens entre des caractéristiques de la situation de conduite et des caractéristiques individuelles menant à des accidents de la route pourront permettre d'adapter les actions de sensibilisation et les modules de formations à la conduite. / The aim of this thesis is to identify the links between the accidents factors among young drivers, by analyzing the effects of situation complexity and driving experience on workload, tension, vigilance and performance. The general hypothesis is that costly situations, i.e. simple and very complex, and the lack of experience can lead to a high energy expenditure. Thus, a high level of tension and a low level of vigilance can provoke performance impairments through the increase of workload, which characterizes an overload of the driver. This should be early observed for novices who had a traditional learning, then for early-trained novices, then for drivers arriving at the end of the probationnary period, and then for the most experienced ones. A first experiment, carried out on subjective data, has confirmed the links beween the levels of workload, tenion and vigilance depending on situation complexity. A second experiment, carried out on subjective and physiological data, has also confirmed the links between the levels of workload, tension and vigilance, with an underestimation of the pysiological level by the traditionally trained novices. The results establishing the links between the driving situation's characteristics and the individuals' characteristics leading to road accidents will allow adapting the awareness actions and the modules of driving trainings.

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