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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.
381

Retour tactile statique et dynamique utilisant le retournement temporel et l'électrovibration / Static and dynamic haptic feedback using time reversal and electrovibration stimulations

Zophoniasson, Harald 26 June 2017 (has links)
Le retour haptique disponible aujourd'hui dans les produits grand public est d'un intérêt limité pour les interactions tactiles et moins efficace que l'utilisation d'un clavier physique pour la saisie de texte. Relativement simple, celui-ci ne peut communiquer que peu d'informations : signaler silencieusement un appel, notification de messages ou confirmation de frappe de touches sur clavier virtuel. Bien que des améliorations aient été apportées aux technologies haptiques existantes, comme des actionneurs plus performants et des gammes de vibrations plus larges afin de simuler des boutons ou des textures, elles restent limitées à un retour tactile unique. Ceci empêche tout usage multi-doigts ou multi-utilisateurs en simultané.Ce travail vise à développer un retour tactile statique et dynamique sur grande surface (format A4). Les interactions avec les écrans tactiles nécessitant un retour tactile plus riche et plus performant, deux types de retour complémentaires ont été identifiés afin de les enrichir. Le retournement temporel des ondes de flexions dans les plaques est étudié afin de simuler l'appui sur un bouton (retour statique). La 2ème approche se base sur la stimulation par électrovibration, qui permet de simuler des textures ou de différencier des zones d'interactions (retour dynamique). Afin d’estimer de manière précise la résolution spatiale du procédé tactile par retournement temporel, un modèle analytique basé sur l'équation de Kirchhoff est proposé. Des mesures expérimentales confrontées au modèle ont permis de le valider. Par ailleurs, des règles de conception sont élaborées et appliquées pour le développement d'un nouveau prototype avec une électronique dédiée sur une plaque en verre de faible épaisseur (1.1 mm). Différents types de signaux de commande sont étudiés. La quantification sur un bit (i.e. signaux de forme carré) avec filtrage des fréquences audibles s’avère être l'alternative la plus efficiente en terme d'amplitude de déplacement générée et de réduction des émissions sonores. Des problématiques de dimensionnement, comme le placement des actionneurs, l'homogénéité de la résolution spatiale et l'amplitude de déplacement sont analysées. L'effet de la force d'appui du doigt sur l'amplitude de déplacement est quantifié (6 % de perte d'amplitude dû à une force d'appui de 2 N sur une localisation autre que le point de focalisation, et jusqu'à 37 % pour la même force d'appui sur le point de focalisation).Le seuil de détection d'une focalisation par retournement temporel mesuré sur 10 utilisateurs se situe à environ 10 µm et est peu influencé par la force d'appui de l'utilisateur sur l'écran. En répétant la focalisation des ondes de manière à former un signal modulé en amplitude, il devient possible de générer des retours tactiles enrichis, notamment de simuler le comportement du clic d’un bouton poussoir. Des motifs avec des fréquences de répétition et des enveloppes différentes sont comparés. Il apparaît qu'une fréquence de 200 Hz et une enveloppe en sinus cardinal sont les plus plaisants pour l’utilisateur.Par ailleurs, l'électrovibration produit des stimuli capables de reproduire une sensation de texture, en modifiant le coefficient de friction entre le doigt et la surface à explorer. L’intensité de ces stimuli dépend de l'épaisseur de peau du bout du doigt. Les seuils de détection des mécanorécepteurs sont dépendants de la fréquence du signal appliqué. Une étude utilisateur ayant pour but de déterminer l'influence de la force d'appui sur le seuil de détection d’une stimulation par électrovibration a été conduite. Les seuils minimaux ont été observés pour une fréquence de 240 Hz. La force d'appui a une influence limitée sur les seuils de détection.La combinaison des deux approches de stimulations (retournement temporel et électrovibration) sur une même surface offre un retour tactile riche et multi-point pour une interaction statique (simulation de clics) et dynamique (simulations de textures). / The current haptic feedback in end user products provides limited tactile interactions and is less efficient than physical keyboards for typing. Most people are used to the simple tactile feedback available in smartphones. However, it is very limited, and can only convey little information: silently signaling a phone call, notifying an incoming message or acknowledging touch inputs when typing on a virtual keyboard. Although advances are made to enrich existing technologies in hand-held devices, such as more efficient actuators with broader ranges of vibrations to emulate buttons or textures, they remain limited to a single point feedback. This prevents any simultaneous multi-user scenario.This work aims to develop static and dynamic haptic feedback on large surfaces (A4 format). Interaction with screen based devices is in need of better and richer haptic feedback. Two types of feedback with complimentary performance are identified as necessary to enrich tactile interactions. Time reversal, as a static feedback technology, is studied to simulate a button press. Electrovibration, as a dynamic feedback, is investigated to simulate tactile textures or to differentiate specific areas of interaction.An analytical model based on Kirchhoff's equation for wave propagation to compute the spatial resolution of time reversal of flexural waves applied to plates is presented. Measurements on a physical system are confronted to the model's prediction. Design guidelines are elaborated and used to develop a new time reversal enabled screen with adapted drive electronics, on a 1.1 mm thick glass plate. Driving signal alternatives are investigated. Signals quantified on one bit (i.e. square type signals) with audible frequencies filtered out are found to be the most efficient in terms of amplitude generation and audible noise emission. Integration issues, such as the actuators’ distribution on the plate and their impact on focalisation point's amplitude and spatial resolution homogeneity are investigated. The effect of the fingertip pressure on the amplitude vibration is studied (6% loss of amplitude due to a 2N force applied by a fingertip on a position other than the focalisation location, and up to 37% for the same force at the focus point's location).The detection threshold measured on ten users is found to be about 10 µm and is not influenced by the force applied on the screen. While a single impact (one impulse) demonstrates the feasibility of time reversal for tactile feedback, a repetition of impacts varying in amplitude offers the possibility to generate richer haptic feedback (such as a button click). Patterns with different repetition frequencies and envelopes are compared in a user study. It appears that frequencies of 200 Hz and the smoothness of the cardinal sine envelope are found to be the best in terms of pleasantness.On the other hand, electrovibration stimulations are able to create a texture feedback by modifying the apparent friction coefficient between the fingertip and the surface. The electrostatic force generation depends on the fingertip skin's thickness. The mechanoreceptors detection threshholds are frequency dependent. A user study on the influence of the applied force on the perception threshold of tactile feedback is presented. The minimum perception thresholds are observed for 240 Hz stimulus. The effect of the applied force appears to have limited effect on the perception threshold.The combination of both stimulation approaches (time reversal and electrovibration) on a single surface will offer a rich multi-point tactile feedback, both for static buttons and dynamic textures.
382

Interaktivní manipulace s 3D objekty se silovou zpětnou vazbou / Interactive Manipulation with 3D Objects with Force Feedbeck

Bělín, Jan January 2009 (has links)
Physical haptic interaction is added to the modern manipulation with objects in virtual space. In content of this master's thesis the haptic technology is represented by SensAble Phantom Omni device and OpenHaptics toolkit, which is related to the device. Reader is initially introduced into mathematical basics of manipulation and into haptic technology history including current state. The introduction into Openhaptics toolkit follows as well as HDAPI and HLAPI libraries description. As a result of this theoretical basics demo aplications have been created, that show basic and advanced abilities of the Phantom Omni device. Demos represent the functionality of the device as examples integrating well-known elementary physical laws and events.
383

VR Touch - Toolkit : Skapandet av ett nytt VR-verktyg för användandet av haptisk feedback och visualisering

Nordeman Malm, Oskar, Elm, Jonathan January 2023 (has links)
Denna undersökning belyser varför beröring är ett viktigt sinne för att stärka VR-upplevelser. Genom att använda beröring som metod för att utforska fysiska egenskaper har vi skapat endigital gestaltning som demonstrerar hur denna unika förmåga kan användas. Denna undersökning har bidragit till skapandet av ett nytt verktyg för framtida utveckling av VR-upplevelser, vilket har öppnat upp möjligheter att använda beröring som huvudmekanik. Genom att kombinera haptisk feedback och visualisering av händer och omgivning kan vi utforska och interagera med VR-spel på ett nytt och spännande sätt. / This study highlights why the sense of touch is important for enhancing VR experiences. By using touch as a method to explore physical properties, we have created a digital representation that demonstrates how this unique ability can be utilized. This study has contributed to the development of a new developer tool for future VR experience design, which has opened up possibilities for incorporating the sense of touch as a main mechanic. By combining haptic feedback and visualization of hands and the environment, we can explore and interact with VR games in a new and exciting way.
384

Passive vs. active wearable technology monitoring trunk flexion in elementary teachers

Jose, Bailey 12 May 2023 (has links) (PDF)
The objective of this study was to assess the biomechanical and subjective measures of elementary school teachers while wearing active and/or passive wearable devices during the average workday. Five elementary school teachers wore a harness that held an Upright GO 2 posture tracking device and a Vicon Blue Trident sensor on the participant's upper back for two school days. Haptic feedback was on for one day and off for the other. Data from the Vicon wearable was analyzed to determine participants’ trunk flexion severity, frequency, and duration. Surveys were used to determine perceived exertion and perception of wearable technology. This study proved that teachers are undergoing severe trunk flexion throughout the day; however, there was not consistent improvement in trunk flexion when haptic feedback was applied. Results also indicated that perceived exertion levels of teachers did not always correlate to the frequency of trunk flexion measured through the wearable device.
385

Realization of a serially-linked haptic device / Framtagning av en serielänkad haptisk enhet

Massoumzadeh, Ramtin January 2017 (has links)
Spatial haptic interfaces have existed for more than 20 years but have not been widespread despite promising applications. The few devices found in the market as of today are either considered costly, of higher quality and produced in smaller series or mass-produced and cheap, but of lower quality. This thesis aims to develop a new serially-linked everyday haptic desktop product under the project name Polhem. It aims to be based on the previous efforts of WoodenHaptics and AluHaptics, developed by Forsslund et al. The electronics and control software is shared between the WoodenHaptics, the AluHaptics as well as the Polhem designed and manufactured in this project. Polhem is capable of delivering forces in 3 DOF and its manipulandum is trackable in 6 DOF. Polhem is designed so as to eliminate problems related to angular tracking technologies currently used in some higher-end haptic devices. / Spatiala haptiska gränssnitt har existerat i mer än 20 år men har trots sina lovande applikationer inte varit tillgänglig i någon större utsträckning. De få enheter som finns på marknaden i dagsläget anses antingen vara dyra, av högre kvalitet och produceras i mindre serier eller massproducerade och billiga, men av lägre kvalitet. Denna avhandling syftar till att utveckla en ny serielänkad haptisk produkt under projektnamnet Polhem. Polhem syftar till att baseras på de föregående enheterna WoodenHaptics och AluHaptics, som utvecklats av Forsslund et al. Elektroniken och reglermjukvaran delas mellan WoodenHaptics, AluHaptics och Polhem. Polhem kan leverera krafter i 3 frihetsgrader och dess manipulandum kan spåras i 6 frihetsgrader. Polhem är utformad så att den eliminerar problem relaterade till äldre vinkelspårningsteknologi som för närvarande används i många högpresterande haptiska enheter
386

Exploring the effect of using vibrate-type haptic glove in the VR industrial training task

Hsu, Yi-Hsiou January 2020 (has links)
Is it a dream came true for you to experience a Virtual Reality (VR) and be able to touch virtual objects and manipulate them with your bare hands? The recent growth of the Virtual Reality market resulted in an intensification of the development of the haptics gloves technology. The newly haptics gloves, Bebop gloves launched and commercialized recently which will use for this study. Earlier research has explored a range of haptics effects mainly on VR surgery or gaming. Yet, VR industrial training has gradually received attention in recent years. Creating multiple scenarios in the virtual scene is not only cost-effective but also increases safety and reduces training time. However, not many research studies have explored using haptic gloves in the VR industrial training environment. This study tries to complement earlier research by investigating usability and user performance using bebop vibration gloves in VR industrial training. The purposes were to provide a usability review of bebop gloves and explored the effect of haptics in VR industrial training. Three different haptics settings (Non-haptics, Partial haptics, and Full-haptics) were being set up. Eighteen users were then recruited to try randomly two haptics settings. Each user had to complete a five steps VR industrial training task while “thinking aloud”, followed by questionnaires and interviews after the task. The error and time recorded for each training step. These results confirmed several conclusions drawn in earlier research about how the haptics affect user performance in the VR environment, as well as how the behavior changes when using the haptics gloves in a VR environment. Last but not least the results also pointed to the importance of vibration haptics benefits in small-scale actions and provide the user with an interpersonal confirmation. / Är det en dröm som förverkligades för dig att uppleva en virtuell verklighet (VR) och kunna röra virtuella objekt och manipulera dem med bara händer? Den senaste tillväxten av marknaden för Virtual Reality resulterade i en intensifiering av utvecklingen av haptikhandskar-tekniken. De nyligen haptiska handskarna, Bebophandskar lanserade och kommersialiserades nyligen som kommer att användas för denna studie. Tidigare forskning har undersökt en rad haptiska effekter främst på VR-kirurgi eller spel. Ändå har VR-industriell utbildning gradvis fått uppmärksamhet under de senaste åren. Att skapa flera scenarier i den virtuella scenen är inte bara kostnadseffektivt utan ökar också säkerheten och minskar tiden. Men inte många forskningsstudier har undersökt användning av haptiska handskar i VR: s industriella utbildningsmiljö. Denna studie försöker komplettera tidigare forskning genom att undersöka användbarhet och användarprestanda med hjälp av bebop-vibrationshandskar i VR-industriutbildning. Syftena var att tillhandahålla en användbarhetsgranskning av bebop-handskar och utforska effekten av haptik i VR-industriutbildningen. Tre olika haptikinställningar (Non-haptics, Partial haptics och Full-haptics) inställdes. Atten användare rekryterades sedan för att testa slumpmässigt två haptikinställningar. Varje användare måste genomföra en femstegs VR-industriell träningsuppgift medan han ”tänker högt”, följt av frågeformulär och intervjuer efter uppgiften. Felet och tiden som registrerats för varje träningssteg. Dessa resultat bekräftade flera slutsatser som dragits i tidigare forskning om hur haptiken påverkar användarnas prestanda i VR-miljön, liksom hur beteendet förändras när man använder haptikhandskarna i en VR-miljö. Sist men inte minst pekade resultaten också på vikten av fördelar med vibrationshaptik i småskaliga åtgärder och ger användaren en interpersonell bekräftelse.
387

Design and control of a three degree-of-freedom planar parallel robot

Joshi, Atul Ravindra January 2003 (has links)
No description available.
388

Control Implementation and Co-simulation  of A 6-DOF TAU Haptic Device / Reglering, implementering och samsimulering av en 6-DOF TAU haptisk enhet

Zhang, Yang January 2020 (has links)
In the research area of virtual reality, the term haptic rendering is defined as the process of computing and generating the interaction force between the virtual object and the operator. One of the major challenges of haptic rendering is the stably rendering contact with a stiff object. Traditional haptic rendering algorithms performs well when rendering contact with soft objects. But when it is used to simulate contact with objects with high stiffness, the algorithm may cause unstable response of haptic devices. Such unstable behavior (e.g., oscillation of the device) can destroy the fidelity of the virtual environment and even hurt the user.  To address the above stability issues, a new design approach has been proposed in this paper. The proposed approach consists of three main process steps: modeling and linearization in ADAMS, LQR position controller design, verification with co-simulation. In the first step, a simulation model of the system is firstly created in ADAMS/View. Then this nonlinear ADAMS multi-body dynamics model is linearized and exported as a set of linear state space matrices with the help of ADAMS/Linear. In the second step, different from the traditional force-control algorithms, LQR position controller is developed in Matlab Simulink based on the exported matrices to emulate interactions with stiff objects. At last, the verification of control performance is carried out by setting up co-simulation between ADAMS and Simulink.  A case study implementation of this proposed method was performed on the TAU device which was previously developed by Machine Design department at KTH. TAU is an asymmetrical parallel robot with six degrees of freedom for the simulation of surgical procedures like drilling and milling of hard tissues of bones and teeth. The results show that the linear model exported from ADAMS is sufficiently accurate and the proposed controller can render a virtual wall with stiffness at the level of 105 N/m. / Inom forskningsområdet virtuell verklighet definieras termen hatisk återgivning (haptic rendering) som processen för beräkning och generering av interaktiva krafter mellan det virtuella objektet och användaren. En av de största utmaningarna med haptisk återgivning är att stabilt simulera känslan av beröring av styv material för användare. Traditionella algoritmer fungerar när det gäller att simulera känslan av beröring av mjuk material, men när algoritmerna används för att simulera kontakt med materialer med stor styvhet kan det orsaka instabilitet hos haptiska enheter. Sådana instabilitet, bland annat svängning hos enheten, kan förstöra den virtuella miljöns exakthet och till och med skada användare.  Denna uppsats försöker ta itu med det ovanstående problemet genom att föreslå en ny designmetod. Metoden består av tre huvudsteg: modellering och linearisering med hjälp av ADAMS, design av LQR-positionskontroll, och verifiering med samsimulering (co-simulation). I det första steget skapas systemets simuleringsmodell med hjälp av ADAMS/View. Sedan linjäriseras denna icke-linjära ADAMS-multikroppsdynamikmodell. Modellen exporteras som linjära tillståndsmatriser med hjälp av ADAMS/Linear. I det andra steget designas en LQR-positionskontroll med hjälp av Matlab Simulink baserat på de exporterade matriserna tidigare för att simulera interaktioner med styv material, vilket skiljer sig från de traditionella kraftkontrollalgoritmer (force-control algorithms). I det sista steget utförs verifieringen av positionskontrollens prestanda genom att ställa in samsimulering (co-simulation) mellan ADAMS och Simulink.  En testkörning av denna föreslagna metod har utförs på TAU-enheten som tidigare utvecklades av KTH institutionen för maskinkonstruktion. TAU är en asymmetrisk parallellsrobot med sex frihetsgrader för att simulera kirurgiska ingrepp som borrning av hårda vävnader i ben och tänder. Resultaten visar att den linjära modellen som exporteras från ADAMS är tillräckligt korrekt, för den föreslagna positionskontrollen kan framställa en virtuell vägg med styvhet vid 105 N/m.
389

The Sensory and Haptic Nature of Art Therapy Materials With Young Children Ages 0-5yrs Old of Complex Trauma

Duncan, Sarah 01 April 2019 (has links) (PDF)
This survey study with an art response aims to further understand how the sensory and haptic nature of art therapy materials can aid in healing within the therapeutic process. Specifically, it will explore young children, ages 0-5yrs old, of complex trauma and how they respond to art materials within the therapeutic process. Surveys were distributed to mental health therapists working with the 0-5 year old population in order to gather baseline information about how young children who have experienced trauma, respond to methods of interventions, including art materials. Through analysis of the participants’ survey responses and artwork, emergent themes revealed insight for further research and reinforced the importance of a consistent, nurturing caregiving relationship. These findings and themes illuminated the importance of relationship and revealed inquiries about the sensory and haptic nature of art materials being utilized for assessment in dyadic therapy with children 0-5 years old.
390

TOWARDS IMPROVING TELETACTION IN TELEOPERATION TASKS USING VISION-BASED TACTILE SENSORS

Oscar Jia Jun Yu (18391263) 01 May 2024 (has links)
<p dir="ltr">Teletaction, the transmission of tactile feedback or touch, is a crucial aspect in the</p><p dir="ltr">field of teleoperation. High-quality teletaction feedback allows users to remotely manipulate</p><p dir="ltr">objects and increase the quality of the human-machine interface between the operator and</p><p dir="ltr">the robot, making complex manipulation tasks possible. Advances in the field of teletaction</p><p dir="ltr">for teleoperation however, have yet to make full use of the high-resolution 3D data provided</p><p dir="ltr">by modern vision-based tactile sensors. Existing solutions for teletaction lack in one or more</p><p dir="ltr">areas of form or function, such as fidelity or hardware footprint. In this thesis, we showcase</p><p dir="ltr">our research into a low-cost teletaction device for teleoperation that can utilize the real-time</p><p dir="ltr">high-resolution tactile information from vision-based tactile sensors, through both physical</p><p dir="ltr">3D surface reconstruction and shear displacement. We present our device, the Feelit, which</p><p dir="ltr">uses a combination of a pin-based shape display and compliant mechanisms to accomplish</p><p dir="ltr">this task. The pin-based shape display utilizes an array of 24 servomotors with miniature</p><p dir="ltr">Bowden cables, giving the device a resolution of 6x4 pins in a 15x10 mm display footprint.</p><p dir="ltr">Each pin can actuate up to 3 mm in 200 ms, while providing 80 N of force and 3 um of</p><p dir="ltr">depth resolution. Shear displacement and rotation is achieved using a compliant mechanism</p><p dir="ltr">design, allowing a minimum of 1 mm displacement laterally and 10 degrees of rotation. This</p><p dir="ltr">real-time 3D tactile reconstruction is achieved with the use of a vision-based tactile sensor,</p><p dir="ltr">the GelSight, along with an algorithm that samples the depth data and marker tracking to</p><p dir="ltr">generate actuator commands. With our device we perform a series of experiments including</p><p dir="ltr">shape recognition and relative weight identification, showing that our device has the potential</p><p dir="ltr">to expand teletaction capabilities in the teleoperation space.</p>

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