• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 5
  • 2
  • Tagged with
  • 9
  • 9
  • 4
  • 4
  • 4
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 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.
1

Conception et réalisation d’une plateforme mécatronique dédiée à la simulation de conduite des véhicules deux-roues motorisés / Design and realization of a mechatronic platform for motorized two-wheeled vehicle riding simulation

Nehaoua, Lamri 10 December 2008 (has links)
Le sujet de thèse concerne la réalisation et la caractérisation d’un simulateur dynamique de véhicule deux-roues. La thèse est organisée en plusieurs parties essentielles. D’abord, une étude bibliographique est menée pour cerner la problématique de la simulation de conduite d’une manière générale en se focalisant sur les simulateurs de point de vue conception. Dans cette partie, on a pris connaissance des différentes architectures mécaniques utilisées auparavant ainsi que les problèmes liés. Le choix de l'architecture du simulateur est guidé par les besoins nécessaires d'avoir une perception suffisante au cours de la simulation de conduite. Notre objectif est de reproduire les effets inertiels (accélération, effort,..) les plus pertinents perçus dans une conduite réelle. Le second chapitre aborde la dynamique des véhicules et compare celle des deux-roues contre les automobiles. Des adaptations pour des modèles dynamiques de moto ont été présentées pour répondre à nos besoins en termes de rendus privilégiés. Le troisième chapitre présente les aspects conception, réalisation, caractérisation et identification du simulateur de moto mis au point dans le cadre de cette thèse. Il constitue la principale contribution de ces travaux de recherche. Les deux derniers chapitres sont dédiés aux algorithmes de contrôle/commande ainsi qu’essais expérimentaux sur la plateforme. Ces tests ont été réalisés en vue de la caractérisation et la validation de performances de toute la chaîne de simulation. / This thesis deals with the design and realization of a dynamic mechanical platform intended to the motorcycle riding simulation. This dissertation is organized into several principal sections. First, a literature review is conducted to identify the driving simulation problematic in a general way by focusing on the simulator design. In this part, it was aware of the various mechanical architectures used previously as well as the related limitations. The choice of the simulator‘s mechanical architecture of is driven by the needs to have an sufficient perception during simulated driving situation. Our goal is to reproduce the most relevant inertial effects (acceleration, torque, ..) perceived in a real world driving. The second chapter discusses an exhaustive comparison between automotive vehicles dynamics against the two-wheeled vehicles against. Existing motorcycles dynamic models are adjusted and of have been adapted to meet our needs in terms of privileged inertial cues. The third chapter presents the design aspects, mechanical realization, characterization and identification of the motorcycle simulator developed within the framework of this thesis. It constitutes the main contribution of this research works. Finally, the last two chapters are dedicated to motion cueing /control algorithms and open-loop experimentation on the simulator’s platform. These tests were performed for the characterization and validation of performance of the entire simulation loop.
2

Investigations into self motion thresholds using a Stewart platform / Investigations into self motion thresholds using a Stewart platform

Akbari, Behzad 06 1900 (has links)
Full motion simulators are traditionally used in the flight industry to train pilots. They are used to add the sensation of acceleration in simulation to make it more "realistic". Clearly the motion envelop of the simulator is limited by physical constraints so the motion platform has to be stopped and returned to the center position after an acceleration cue, called washout. A key question is: which acceleration can a subject feel and which not, called the acceleration threshold. We are also interested in strength of accelerations for which a subject can detect the direction. Literature gives several results, but we found that some of these values seemed very low to us and the experiments were conducted on very specific groups of people like pilots, A.J.Benson and H.Vogel (1986), Schroeder (1999). Furthermore, we are simulating moving vehicles like a car or an air plane and are interested in the acceleration ranges in a noisy environment. Noisy, the noise is a result from the vibration of engines, rough roads and disturbances that are Gaussian. This thesis gives a literature review, implement the cueing procedure to make motion and vibration to do different experiment and analyze the results. / Thesis / Master of Computer Science (MCS)
3

Three Degree-of-Freedom Simulator Motion Cueing Using Classical Washout Filters and Acceleration Feedback

Gutridge, Christopher Jason 03 May 2004 (has links)
Good motion cueing in a flight simulator serves to enhance the overall simulation environment. However, poor motion cueing can greatly detract from the simulation and serve solely to distract the pilot. The latter was the case for Virginia Tech's three degree-of-freedom motion-base. The most common method of motion cueing is to use washout filters to produce the best motion cues within the physical limitations of the motion system. This algorithm is named the classical washout algorithm and its filters were studied first in this research, but initially yielded undesirable results. In efforts to greatly improve the acceleration response in the pitch axis, the concept of an acceleration feedback controller in conjunction with washout filters was investigated. In developing a mathematical model of the motion-base and its corresponding circuitry, corrections and modifications were made to the circuitry which served to improve the dynamic response of the motion-base and enhance motion sensations. Next, design and implementation of the acceleration feedback controller for the pitch axis was performed and tested using a pilot rating scale and time history responses. The parameters for the acceleration feedback algorithm and the classical washout algorithm were varied to find the most favorable algorithm and set of parameters. Results of this paper have demonstrated the successful implementation of acceleration feedback and that the motion system at Virginia Tech now serves to greatly enhance the simulation environment. / Master of Science
4

Evaluation of Motion Cueing Algorithms for a Limited Motion Platform Driver-in-Loop Simulator

Sekar, Rubanraj 13 August 2020 (has links)
No description available.
5

The Development of an Adaptive Driving Simulator

Tudor, Sarah Marie 12 March 2015 (has links)
The ability to drive a car is an important skill for individuals with a spinal cord injury to maintain a high quality of life, particularly their freedom and independence. However, driving with a physical disability often requires the installation of an adaptive driving system to control steering, gas, and braking. The two main types of adaptive driving controls are mechanical and electrical, also known as drive by wire (DBW). DBW controls work by converting electric signals to mechanical actuators. Driving simulators are useful tools for adaptive driving systems because they allow users to test different control devices, to practice driving without the dangers of being on the road, and can be used as a safe way to evaluate disabled drivers. This study focused on the development of a dynamic driving simulator using DBW controls because many studies focus on mechanical controls and not DBW controls and often use static simulators. The simulator was developed using the Computer Assisted Rehabilitation Environment (CAREN) virtual reality system. The CAREN system (Motek Medical, Amsterdam, Netherlands) includes a six degree of freedom (DOF) motion base, an optical motion capture system, a sound system, and a 180-degree projection screen. The two DBW controls, a lever device to control the gas and brake and a small wheel device to control steering, sent an electric signal to a Phidget microcontroller board, which interfaced with the CAREN system. Several different driving scenarios were created and imported into CAREN's D-Flow software. A program was developed in D-Flow to control the scene and motion of the platform appropriately based on the DBW controls via the Phidget. The CAREN system dynamically controlled the motion platform based on the user's input. For example, if the user applied the brake suddenly, the user felt a deceleration from the motion platform moving backwards. Human testing was performed and through the use of a survey, feedback about the system was obtained. Changes were made to the simulator using the feedback obtained and further testing showed that those changes improved the simulator. The driving simulator showed the capability to provide dynamic feedback and, therefore, may be more realistic and beneficial than current static adaptive driving simulators. The dynamic adaptive driving simulator developed may improve driving training and performance of persons with spinal cord injuries. Future work will include more human testing. The dynamic feedback provided through the system's moving platform and virtual camera movement will be optimized in order to perform similarly to a real car. Testing will also be completed with and without the dynamics from the moving platform to see how this type of feedback affects the user's driving ability in the virtual environment.
6

Comparison between filter- and optimization-based motion cueing algorithms for driving simulation

Cleij, Diane, Venrooij, Joost, Pretto, Paolo, Katliar, Mikhail, Bülthoff, Heinrich, Steffen, Dennis, Hoffmeyer, Friedrich W., Schöner, Hans Peter 25 September 2020 (has links)
This paper describes a driving simulation experiment, executed on the Daimler Driving Simulator (DDS), in which a filter-based and an optimization-based motion cueing algorithm (MCA) were compared using a newly developed motion cueing quality rating method. The goal of the comparison was to investigate whether optimization-based MCAs have, compared to filter-based approaches, the potential to improve the quality of motion simulations. The paper describes the two algorithms, discusses their strengths and weaknesses and describes the experimental methods and results. The MCAs were compared in an experiment where 18 participants rated the perceived motion mismatch, i.e., the perceived mismatch between the motion felt in the simulator and the motion one would expect from a drive in a real car. The results show that the quality of the motion cueing was rated better for the optimization-based MCA than for the filter-based MCA, indicating that there exists a potential to improve the quality of the motion simulation with optimization-based methods. Furthermore, it was shown that the rating method provides reliable and repeatable results within and between participants, which further establishes the utility of the method.
7

Objective motion cueing tuning for vehicle dynamics evaluation in winter conditions

Hvitfeldt, Henrik January 2024 (has links)
Vehicle manufacturers strive for an increasingly efficient and faster development process. Although computer-aided engineering has made significant progress toward a fully virtual development process, a challenge remains in integrating human subjective feedback to fully close the virtual development loop. Subjective assessment of ride and driving characteristics are still very important traits of a passenger car. Moving-base driving simulators have the ability to introduce the human into the virtual development loop, thus enabling subjective assessment of virtual vehicle models. Such an introduction has the potential to significantly speed up the development process and at the same time save resources by avoiding physical testing and providing informed decisions in the early phase of vehicle development cycles. The challenge to do so lies in the possibility to evaluate a vehicle in a driving simulator, which is highly dependent on the motion cueing. Motion cueing algorithms are used to map the vehicle motion into the confined workspace of a driving simulator. As of today, these algorithms are still often tuned and evaluated subjectively. The challenge with this approach is that it does not guarantee the fidelity of the cueing and it needs physical vehicles to be compared with. This work thus focuses on the objective development and evaluation of motion cueing, which potentially could enable high fidelity motion cueing in the early stages of the vehicle development process, when prototypes are not available. This is very important for winter testing since the testing is challenging with regards to ambient conditions, the limited testing season and the increasing need to speed up the development process. The goal of this work is to move towards an objective approach to cueing evaluation based on physical models combining vehicle model, simulator, and human. Therefore, this thesis presents an objective methodology to motion cueing evaluation and development. Based on the state-of-the-art review, this work addresses the need for simple linear models to evaluate the fidelity of motion cueing algorithms. The linear model is applied to the problem of positioning the longitudinal axis of rotation of the simulator cabin and shows promising results when compared to time series-based optimisation and subjective assessment. Furthermore, using the same model to improve the motion cueing by introducing tilt coordination shows that even though the immersion is improved, the tilt coordination changes the perceived vehicle characteristics. To objectively evaluate different yaw cueing strategies in winter conditions, a more detailed human model is introduced that extends the state-of-the-art vestibular organ models by introducing gaze stabilisation using a model of the vestibulo-collic reflex. The cueing evaluation indicates the potential of separating slip angle feedback from the high-pass filtering of motion cues, as well as the advantage of using the vehicle’s motion as a target for cueing optimisation rather than the human vestibular response in winter handling evaluation. By addressing the inherent skewing of vehicle characteristics in motion cueing and suggesting improvements to the evaluation and cueing strategies, this work contributes to the possibility of virtually evaluating the vehicle dynamic characteristics in driving simulators under winter conditions.
8

Teleoperation and the influence of driving feedback on drivers’ behaviour and experience

Zhao, Lin January 2023 (has links)
Automated vehicles (AVs) have been developing at a rapid pace over the past few years. However, many difficulties still remain for achieving full Level-5 AVs. This signifies that AVs still require human operators to intervene or assist, such as taking over control of AVs or selecting their routes. Therefore, teleoperation can be seen as a subsystem of AVs that can remotely control and supervise a vehicle when needed. However, teleoperated driving conditions are largely different from real-life driving, so remote drivers may experience different driving feedback. In such a situation, therefore, the driving behaviour and performance of remote drivers can also be impacted. The following three studies were conducted to investigate these points. First, a seamless comparative study was carried out between teleoperated and real-life driving. Driving behaviour and performance were compared in two scenarios: slalom and lane following. Significant differences in driving behaviour and performance between them were found in the study. The lane following deviation during teleoperated driving is much greater than that of real-life driving. In addition, remote drivers are more likely to drive slower and make more steering corrections in lane following manoeuvres. Second, three types of steering force feedback (SFF) modes were compared separately in both teleoperated and real-life driving to investigate the effect of SFF on driving experience. The three SFF modes consist of Physical model-based steering force Feedback (PsF), Modular model-based steering force Feedback (MsF), and No steering force Feedback (NsF). The difference between PsF and MsF is that the main forces come from different sources, namely the estimated tyre force and steering motor current, respectively. As expected, the experimental results indicate that NsF would significantly reduce the driving experience in both driving conditions. In addition, remote drivers were found to require reduced steering feedback force and returnability. Finally, the influence of motion-cueing, sound, and vibration feedback on driving behaviour and experience was studied in a virtual teleoperation platform based on the IPG CarMaker environment. The prototype of a teleoperated driving station (TDS) with motion-cueing, sound, and vibration feedback was first developed to study human factors in teleoperated driving. Then, the low-speed disturbance scenario and high-speed dynamic scenario were used separately to investigate how these factors affect driving. Experimental results indicate that sound and vibration feedback can be an important factor in speed control by providing remote drivers a sense of speed. In the low-speed disturbance scenario, motion-cueing feedback can help with road surface perception and improve the driving experience. However, it did not significantly improve driving performance in the high-speed dynamic scenario. The research conducted reveals how driving behaviour may change in teleoperated driving and how different driving feedback influences it. These results could provide guidance for improving teleoperated driving in future research and serve as a guide for policymaking related to teleoperation. / Självkörande fordon (AV) har utvecklats i snabb takt de senaste åren. Men det finns fortfarande många utmaningar innan man når  helt självkörande fordon. Följaktligen krävs fortfarande säkerhetsförare när AV-enheter är i drift och i framtida drift kan AV-enheter stöta på oväntade problem som en människa behöver lösa. Fjärrövervakning kan därför ses som ett  backupsystem, som kan fjärrstyra och övervaka fordonet när det inte fungerar. Men situationen  vid fjärrstyrning är helt annorlunda än för körning i verkligheten, där fjärroperatörer kan uppleva olik återkoppling  och känslor jämfört med körning i verkligheten. Därför kan även fjärroperatörernas körbeteende och prestanda ändras i denna situation. För att undersöka detta utfördes följande tre studier. För det första genomfördes en sömlös jämförelsestudie mellan fjärrstyrning och verklig körning. Körbeteende och prestanda jämfördes i två scenarier, nämligen slalom och linjeföljning. Signifikanta skillnader i körbeteende och prestanda hittades mellan fjärrstyrning och körning i verkligheten. Avvikelse från linjeföljning vid fjärrstyrning är betydligt större än för körning i verkligheten. Dessutom är det mer sannolikt att fjärroperatörer kör i lägre hastigheter och gör fler styrkorrigeringar vid fjärrstyrning.  För det andra jämfördes tre typer av styrkraftsåterkopplingsmodeller (SFF) separat i både fjärrstyrning och verklig körning för att undersöka SFF:s inverkan på körupplevelsen. De tre SFF-modellerna inkluderar en  modell för fysisk återkoppling (PsF), modell för modulär återkoppling (MsF) och ingen återkoppling (NsF). Skillnaden mellan PsF och MsF är att huvudkrafterna härrör från olika källor, nämligen respektive från den matematiskt uppskattade däckkraften och från styrmotorströmmen. Som förväntat tyder resultaten av experimentet på att NsF avsevärt skulle minska körupplevelsen vid både fjärrstyrning och körning i verkligheten. Vid fjärrstyrning upptäcktes också  att operatörer kräver minskad styråterkopplingskraft och returförmåga.  Slutligen studerades påverkan av rörelsestyrning, ljud och vibrationsfeedback på körbeteende och upplevelse. Prototypen av fjärrkontrolltorn  med rörelsestyrning, ljud och vibrationsfeedback utvecklades först för att studera mänskliga faktorer vid fjärrstyrning. Sedan användes ett låghastighetsscenario med störningar och det dynamiska höghastighetsscenariot separat för att undersöka hur dessa faktorer påverkar körning vid fjärrstyrning. Resultaten av experimentet indikerar att ljud- och vibrationsåterkoppling kan vara till stor hjälp för att reglera  hastigheten genom att ge operatörerna medvetenhet om hastighet. I låghastighetsscenariot kan återkoppling  från rörelsestyrning underlätta uppfattningen av vägytan och förbättra körupplevelsen. Den ökade dock inte nämnvärt dynamisk körprestanda  i hög hastighet.  Denna forskning undersöker hur körbeteendet kan förändras vid fjärrstyrning och hur olika återkopplingar till operatör påverka körning på distans. Dessa resultat kan  ge vägledning om hur man kan förbättra fjärrstyrning i framtida forskning och fungera som en referens för skapande av regler kopplat till fjärrövervakning och fjärrstyrning. / <p>QC 230504</p>
9

Etude des liens entre immersion et présence pour la mise au point d'un simulateur de conduite de deux-roues motorisé / Study of the relationship between immersion and presence to develop a powered two-wheelers simulator

Dagonneau, Virginie 12 October 2012 (has links)
Les environnements virtuels, et en particulier les simulateurs de conduite à plate-forme dynamique, posent la délicate question de la restitution multisensorielle en vue de générer la bonne "illusion" pour leurs utilisateurs. Si la réalité virtuelle est reconnue pour la limitation des coûts, le gain temporel et la contrôlabilité et reproductibilité des situations étudiées, la problématique de la validité de ces outils de recherche (ou de formation) est cruciale pour la transférabilité des connaissances produites.Constituant une première étape dans le processus de validation du simulateur IFSTTAR, ce travail s’appuie sur une démarche originale reposant sur une double évaluation, par élément et globale. Il s’agit (i) de configurer de manière optimale les caractéristiques immersives et interactives du simulateur liées au mouvement de roulis afin de produire une illusion d’inclinaison crédible et acceptée, et (ii) d’évaluer, de manière globale, différentes configurations du simulateur (modèles dynamiques de véhicule) au moyen de mesures objectives (temps de familiarisation) et subjectives (présence, mal du simulateur).Prises dans leur ensemble, les sept études menées durant cette thèse ont permis de valider une plage de restitution du mouvement de roulis pertinente pour produire une sensation d’inclinaison sans entraîner de déséquilibre critique ou de sensation de chute. Un angle d’inclinaison du simulateur au-delà de 11,4 degrés est ainsi déconseillé pour éviter toute sensation de chute, néanmoins cette valeur est susceptible d’être influencée par divers facteurs (e.g., présence d’informations visuelles, positionnement de l’axe de roulis). Ces études ont également permis d’identifier, en conduite passive, les paramètres nécessaires ainsi que les contributions relatives des informations visuelle et inertielle pour la production d’une sensation d’inclinaison crédible. En conduite active, l’évaluation du degré de contrôle des participants en fonction du modèle dynamique de véhicule (virtuel) a permis de pointer les faiblesses actuelles du simulateur IFSTTAR afin de proposer plusieurs pistes de développement. / Virtual environments, and specifically motion-based driving simulators, raise the delicate question of multisensory cueing in order to produce the good "illusion" to the users. If virtual reality is well acknowledged for cost limitation, validity issue of these research (or training) tools is critical for knowledge transfer of new results.As a first step in the validation process of the IFSTTAR motorcycle simulator, this work relies upon an original design based on a double approach : by element and global. It consists in (i) optimal balancing of simulator’s immersive and interactive characteristics linked to roll motion so as to yield a believable and embraced leaning illusion, and (ii) evaluating more generally different simulator configurations (vehicle dynamic models) through objective (training length) and subjective measures (presence, simulator sickness).Taken as a whole, the seven studies conducted during this thesis enable the validation of the relevant range of roll motion cueing to produce a leaning sensation without leading to a critical unbalance or fall sensation. A leaning angle of the simulator beyond 11.4 degrees is not recommended to avoid any fall sensation, however this figure can be influenced by various factors (e.g., visual informations, roll axis location). These studies also allow to identify, in passive driving situations, the necessary parameters as well as the relative contribution of visual and inertial informations for the production of a believable leaning sensation. In an active driving situation, the evaluation of the degree of users control through different (virtual) vehicles dynamic models has permitted to highlight the weaknesses of IFSTTAR simulator in order to set several guidelines for further development.

Page generated in 0.0853 seconds