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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.
531

Facial Expressions as Indicator for Discomfort in Automated Driving

Beggiato, Matthias, Rauh, Nadine, Krems, Josef 26 August 2021 (has links)
Driving comfort is considered a key factor for broad public acceptance of automated driving. Based on continuous driver/passenger monitoring, potential discomfort could be avoided by adapting automation features such as the driving style. The EU-project MEDIATOR (mediatorproject.eu) aims at developing a mediating system in automated vehicles by constantly evaluating the performance of driver and automation. As facial expressions could be an indicator of discomfort, a driving simulator study has been carried out to investigate this relationship. A total of 41 participants experienced three potentially uncomfortable automated approach situations to a truck driving ahead. The face video of four cameras was analyzed with the Visage facial feature detection and face analysis software, extracting 23 Action Units (AUs). Situation-specific effects showed that the eyes were kept open and eye blinks were reduced (AU43). Inner brows (AU1) as well as upper lids (AU5) raised, indicating surprise. Lips were pressed (AU24) and stretched (AU20) as sign for tension. Overall, facial expression analysis could contribute to detect discomfort in automated driving.
532

Jeřábová kočka 32t / Crab of crane 32t

Elsner, Ondřej January 2011 (has links)
This thesis deals with design four-wheel crab of crane for overhead crane with capacity of 32,000 kg. Contains the functional calculations of steel rope , pulleys, cable drum. The integral part of the thesis constitutes the calculation and choice of driving mechanism for lifting, travel drive and motor drive pulley block hook rotation.
533

Optimiser la validité des comportements observés sur simulateur de conduite : étude des interactions entre immersion, présence et comportement / Optimizing the validity of behaviors observed on driving simulator : study of the interactions between immersion, presence and behavior

Deniaud, Christophe 08 December 2017 (has links)
Les simulateurs de conduite permettent d’étudier le comportement humain dans différentes conditions fixées expérimentalement. Un avantage majeur de la simulation est de ne pas exposer le sujet à un risque objectif et que les conditions de test sont "facilement" mises en œuvre et manipulées. Le recours à la simulation pose néanmoins la question de la généralisation et transposition des comportements observés en simulation à la situation réelle de conduite. En effet, il est nécessaire de s’assurer que le simulateur mesure précisément l’objet d’étude sans le modifier ou l’influencer. L’évaluation du degré de validité est donc cruciale dans toute étude sur simulateur qui cherche à susciter des comportements réalistes de conducteurs. Le postulat de notre travail repose donc sur l’idée que la présence est un concept clé pour évaluer la représentativité des comportements de conduite observés en simulation. Toutefois plusieurs difficultés seront à résoudre. Une des plus cruciales repose sur le fait que la présence est difficilement mesurable en temps réel puisque le fait même de chercher à la mesurer peut rompre l’état de présence plus ou moins existant. Ainsi obtenir des indicateurs comportementaux de la présence constitue un véritable enjeu pour caractériser la nature d’un phénomène qui à l’heure actuelle est davantage fantasmé à l’aide de mesures post-expérimentation que concrètement démontré par la mise en évidence de comportements spécifiques reproductibles. / Driving simulators make it possible to study human behavior in different experimentally determined conditions. A major benefit of simulation is that it does not expose the subject to an objective risk and that test conditions are "easily" implemented and manipulated. The use of simulation nevertheless raises the question of the generalization and transposition of the behaviors observed in simulation to the actual driving situation. Indeed, it is necessary to ensure that the simulator accurately measures the object of study without modifying or influencing it. Assessing the degree of validity is therefore crucial in any simulator study that seeks to create realistic driver behaviors. The postulate of our work is therefore based on the idea that presence is a key concept for assessing the representativeness of driving behaviors observed in simulation. However, several difficulties will have to be solved. One of the most crucial is the fact that presence is difficult to measure in real time because the very fact of trying to measure it can break the more or less existing presence state. Thus, to obtain behavioral indicators of presence is a real challenge to characterize the nature of a phenomenon which at present is more fantasized by post-experimental measures than concretely demonstrated by the demonstration of specific reproducible behaviors.
534

Analysis of vehicle ergonomics using a driving test routine in the DHM tool IPS IMMA

Romera Orengo, Javier January 2020 (has links)
The objective of this project is to develop a driving test using a Digital Human Modeling tool (DHM), specifically IPS IMMA, which will allow the evaluation of the ergonomics of the interior of vehicles as currently demanded by the automotive companies. Thus, improving both the design and the design process. This will involve a study of the driving and the tasks carried out by a real person to end up programming them in the DHM software. Based on this study an interface is suggested that guides engineers or ergonomists to design their own driving tests and enable them to evaluate their own designs without a high specialization in DHM tools and software. Taking into account the already present autonomous cars and their future development, the conceptual design of a two positions steering wheel (autonomous/manual driving) will be introduced as an example to be added in the driving test. This example is intended to show how DHM tools can be used to evaluate different designs solutions in early stages of the product development process. This project will be a contribution to one of the sections of the ADOPTIVE project carried out at the University of Skövde and in collaboration with Swedish automotive companies.
535

Exploration of Weather Impacts on Freeway Traffic Operations and Safety Using High-Resolution Weather Data

Dai, Chengyu 01 January 2011 (has links)
Adverse weather is considered as one of the important factors contributing to injuries and severe crashes. During rainy conditions, it can reduce travel visibility, increase stopping distance, and create the opportunity hydroplaning. This study quantified the relative crash risk on Oregon 217 southbound direction under rainy conditions by using a match-paired approach, applied one-year traffic data, crash data and NEXRAD Level II radar weather data. There are 26 crashes occurred in match-paired weather conditions for Oregon 217 in year 2007. The results of this study indicate that a higher crash risk and a higher property-damage-only crash risk occurred during rainy days. The crash risk level varies by the location of the highway, at milepost 2.55 station SW Allen Blvd has the highest driving risks under rainy conditions.
536

Deep Learning Based Motion Forecasting for Autonomous Driving

Dsouza, Rodney Gracian 07 October 2021 (has links)
No description available.
537

Telematics and Contextual Data Analysis and Driving Risk Prediction

MoosaviNejadDaryakenari, SeyedSobhan 25 September 2020 (has links)
No description available.
538

Using Simulation-Based Testing to Evaluate the Safety Impact of Network Disturbances for Remote Driving / Simuleringsbaserad Testning för att Utvärdera hur Nätverksstörningar Påverkar Säkerheten vid Fjärrkörning

Trivedi, Shrishti January 2023 (has links)
The transportation industry has been transforming because of rapid digitalization and autonomy. Because of this the demand for more connected and autonomous vehicles is increasing for both private individuals and businesses. Reducing human interaction emphasizes the need for higher road safety. Autonomous vehicles, in general, have different sources of faults which might lead to severe accidents and injuries. Testing and validating autonomous vehicles can be useful for avoiding such cases. Remote driving is a potential fallback option whenever autonomous vehicles fail. The remote operator can take direct or indirect control of the remotely-operated vehicle whenever the need arises. Tele-operated driving has three main parts - the vehicle, the remote operator, and communication between the two. Communication plays an important role in this feedback control system. Any communication disturbance in the video feed from the vehicle to the remote operator or in the commands from the operator to the vehicle can result in safety violations and even accidents. These disturbances can have different sources. This work presents a methodology to inject network disturbances to analyze the effect of these disturbances on vehicle manoeuvrability. A driving simulator, CARLA, was used as a vehicle model to solve this problem and to allow human-in-the-loop. NETEM was used to inject different faults on the outgoing traffic to emulate network disturbances. The implementation was done on LocalHost to avoid any delays that might occur due to the presence of physical devices in the network. It was concluded from the Time-to-Collision (TTC) results that road safety decreased whenever the fault was injected in a vehicle-following case. Another important insight was that the packet loss of 5% always showed a TTC violation for a 6-sec threshold. The highest steering reversal rate was also observed for 5% packet loss. It was observed from the results that the steering reversal rate (SRR) was consistently higher in the faulty run. This indicates that the drivers were more distracted. Based on the results, it is observed that network disturbances affected driving in a remote driving setup. The results can be further utilized for more comprehensive studies to understand how simulator-in-loop can be used for testing, verification, and validation. / Transportbranschen har förändrats på grund av snabb digitalisering och autonomi. Efterfrågan på mer uppkopplade och autonoma fordon ökar hos både privatpersoner och företag. Men minskad användarinteraktion ökar behovet av högre säkerhet hos fordonen. Autonoma fordon har i allmänhet olika felkällor som kan leda till allvarliga olyckor och skador. Att testa och validera autonoma fordon blir viktigt för att undvika sådana fall. Fjärrkörning är ett potentiellt komplement när autonoma fordon inte är tillräckligt säkra. Fjärroperatören kan ta direkt eller indirekt kontroll över det fjärrmanövrerade fordonet när behovet uppstår. Telestyrd körning har tre huvudkomponenter - fordonet, fjärroperatören och kommunikationen däremellan. Kommunikation spelar en viktig roll i detta återkopplade system. Varje störning i kommunikationen av videoflödet från fordonet till fjärroperatören eller i kommandon från operatören till fordonet kan resultera i bristande säkerhet och till och med olyckor. Dessa störningar kan ha olika källor. Detta arbete presenterar en metod för att injicera nätverksstörningar för att kunna analysera effekten av dessa på fordonets manövrerbarhet. En körsimulator, CARLA, användes som fordonsmodell och anpassades för att kunna styras av en mänsklig fjärroperatör. NETEM användes för att injicera olika fel på den utgående nätverkstrafiken för att efterlikna nätverksstörningar. Implementeringen gjordes på LocalHost för att undvika fördröjningar som kan uppstå på grund av närvaron av andra fysiska enheter i nätverket. Av TTC-resultaten drogs slutsatsen att trafiksäkerheten minskade när fel injicerades i ett fall där fjärroperatören följer att annat fordon. En annan viktig insikt var att en paketförlust på 5% alltid gav överträdelser med för låg TTC vid en gräns för lägsta tillåtna värde på 6 sekunder. Även de högsta observerade värdena på styrvändningstakt (steering reversal rate) observerades för 5% paketförlust. Resultaten visade att styrvändningstakten konsekvent var högre vid felinjicering. Detta tyder på att förarna var mer distraherade. Baserat på resultaten är en observeration att nätverksstörningar kan påverka säkerheten vid fjärroperation. Metodiken kan användas för mer omfattande studier för att förstå hur simulator-i-loopen kan användas för testning, verifiering och validering.
539

Assessing Moisture Resilience of Wall Assemblies to Wind-Driven Rain Loads Arising from Climate Change

Xiao, Zhe 18 February 2022 (has links)
Moisture loads arising from the deposition of wind-driven rain (WDR) on building façades can induce detrimental effects to wall assembly components and can adversely influence their long-term performance. Wind-driven rain as a climatic phenomenon will inevitably be affected by the evident changing climate in the near future. Wall assemblies subjected to wind-driven rain loads will also perform differently due to a varying moisture environment over the course of time. The performance of the building envelope, including the wall assembly, largely determines the serviceability of a building over its life cycle. Thus, it is essential for practitioners to understand and to be able to assess such performance. In this study, a complete procedure has been developed to permit assessing the moisture resilience of wall assemblies to wind-driven rain loads arising from climate change. The development of this procedure included four phases. In the first phase the historical and projected climate data was analysed to identify the possible wind-driven rain conditions to which a wall assembly may be exposed. The magnitudes of wind-driven rain and driving-rain-wind-pressure for different return periods were also investigated. Based on the results from phase one, a watertightness test protocol was established taking into consideration the possible ranges of wind-driven rain and driving-rain-wind-pressure as they may occur spatially, as well as temporally, across Canada. The range of watertightness test parameters was accommodated in the newly built Dynamic Wind and Wall Testing Facility (DWTF) at the National Research Council Canada. Thereafter in phase two of the research, wall assemblies having different configurations were tested in the DWTF following the test protocol to obtain the moisture load for wall assemblies under different wind-driven rain conditions. Such moisture loads were formulized and used in the third phase, where hygrothermal simulations were conducted to derive the hygrothermal parameters of the wall assemblies subjected to historical and projected climate data. In the final research development phase, different criteria and methods were explored to describe the performance of wall assemblies based on the hygrothermal parameters. During the development of the moisture resilience assessment procedure, a novel wind-driven-rain-pressure-index was devised to describe the extent of the effects arising from the concurrent action of wind-driven rain and driving-rain-wind-pressure loads on a vertical wall assembly; a new two-step approach was established to formulize the watertightness test results and thereby permit calculating the moisture load using values of hourly wind-driven-rain and hourly driving-rain-wind-pressure of a given location; a novel severity index was proposed to quantitatively describe the damage events arising from such moisture load on the wall assemblies. The moisture performance of tested wall assemblies subjected to historical and projected future climate were compared and discussed. The risks of occurrence of damage events in wall assemblies during different time periods were also demonstrated.
540

<b>AUTOMATION-TO-HUMAN TRANSITION OF CONTROL: </b><b>AN EXAMINATION OF PRE-TRANSITION BEHAVIORS THAT INFLUENCE READINESS TO TAKE OVER FROM CONDITIONALLY AUTOMATED VEHICLES</b>

Nade Liang (7044191) 08 March 2024 (has links)
<p dir="ltr">Automated Driving Systems (ADS) have evolved significantly over the past decade. With conditionally automated driving systems still requiring constant driver supervision and human intervention upon system request, a driver’s readiness to take over from an ADS has significant safety implications. Research suggests that drivers using ADS are more likely to engage in non-driving-related tasks (NDRTs), and this engagement can deteriorate takeover performance. However, different NDRTs can involve engagement of physical, visual and/or cognitive resources, which all can affect the takeover process in different ways. The potential interaction effects among these factors may be the cause of mixed empirical findings regarding the influence of NDRT engagement on takeover readiness and performance. Additionally, with more advanced ADS, takeover scenarios are likely to be less urgent. Yet, the ways in which drivers behave in response to a takeover request to intervene during such less urgent scenarios while engaged in NDRTs is still not well understood.</p><p dir="ltr">The purpose of this dissertation is to provide a better understanding of drivers’ response behavior during a conditionally automated vehicle takeover process by analyzing drivers’ motor, visual, and cognitive readiness in response to a takeover request (TOR). The work was completed in two phases. The first phase focused on the effects of pre-takeover visual engagement on takeover readiness in urgent situations. Two experiments were conducted as part of this first phase. Particularly, Study 1 investigated drivers’ post-TOR visual attention allocation and cognitive readiness after continuous visual NDRT engagement before a TOR. Study 2 examined drivers’ pre-TOR visual attention allocation and takeover performance both during and after voluntary engagement with visual NDRTs. The second phase used a non-urgent takeover scenario to investigate drivers’ takeover behavior and visual attention allocation when prioritizing the engagement of visual-manual NDRTs that differed in terms of cognitive engagement levels.</p><p dir="ltr">Study 1 required continuous visual attention in NDRTs and manipulated only the location of visual attention before an auditory TOR. Dependent measures included duration, location, and directness eye-tracking measures after the TOR, as well as freeze-probe cognitive readiness scores. Overall, delayed visual attention re-allocation in the driving scene, less dispersed gaze patterns, and worse perception and comprehension of road hazards were associated with off-road visual NDRT engagement. In addition, no significant benefit of enforcing on-road visual attention before the TOR, compared to the baseline condition without NDRT requirements, were found. These findings highlight the need to investigate the effects of more naturalistic NDRT engagement on takeover attention reallocation and takeover performance.</p><p dir="ltr">Study 2 complemented Study 1 by allowing voluntary switching of visual attention between the NDRT and the driving scene prior to the TOR, with the driving task being a priority. In addition, Study 2 investigated drivers’ takeover quality and understanding of the takeover scene using the appropriateness of their takeover decisions. Dependent measures were pre- and post-takeover eye-tracking measures, aligning to those used in Study 1, in addition to motor response measures, longitudinal and lateral vehicle control measures, and decisions made in response to a road obstacle. Overall, the driver’s post-TOR behaviors were not significantly affected by NDRT conditions, but visual NDRT-induced differences in gaze distribution were associated with the appropriateness of takeover decisions.</p><p dir="ltr">Finally, Study 3 used knowledge from prior studies to isolate the effects of different levels of cognitive engagement in real-world visual-manual NDRTs. The purpose was to investigate the effects of cognitive engagement on drivers’ visual attention allocation before and during the takeover, as well as on takeover performance in non-urgent takeover scenarios, where NDRT engagement was a priority. Dependent measures included eye-tracking measures, takeover response time, and vehicle control measures, used in prior studies. In summary, engagement in NDRTs with higher levels of cognitive engagement resulted in significant differences in pre-TOR visual attention allocation and less stable takeover maneuvers.</p><p dir="ltr">The findings from this work contribute to a better understanding of the effects of different components of NDRT engagement on takeover performance in conditionally automated driving systems. Ultimately, this work can contribute to improving the design of next-generation human-machine interfaces in surface transportation, including driver monitoring systems and in-vehicle displays, that promote safer human-automation integration in future ADS.</p>

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