• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 214
  • 48
  • 29
  • 28
  • 12
  • 5
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 3
  • 2
  • 2
  • Tagged with
  • 428
  • 85
  • 83
  • 77
  • 67
  • 65
  • 62
  • 61
  • 58
  • 54
  • 53
  • 50
  • 48
  • 47
  • 44
  • 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.
321

Constance spatiale haptique et attribution distale / Haptic spatial constancy and distal attribution

Dupin, Lucile 30 November 2015 (has links)
L'environnement dans lequel nous évoluons nous apparaît comme stable. Il nous semble exister indépendamment de notre mouvement et du sens à partir duquel nous le percevons. Or, chacun de nos déplacements peut modifier l'information sensorielle : l'image rétinienne est constamment modifiée lorsque nous sommes en mouvement ou l'information tactile lorsque nous déplaçons la main pour identifier un objet. Par ailleurs, les éléments extérieurs peuvent se déplacer produisant également une modification de la stimulation de nos capteurs. La connaissance de notre propre mouvement dans cet environnement est un élément essentiel permettant de distinguer les modifications sensorielles liées à notre propre action de celles qui nous sont extérieure. Le mouvement est généralement réalisé par le capteur sensoriel: celui-ci subit la modification de stimulation liée à son propre déplacement. Le toucher est fondamentalement une modalité active car, l'objet exploré tactilement est généralement plus grand que la surface de peau utilisée pour ce faire. Le mouvement permet donc de reconstituer spatialement les caractéristiques de l'objet, en associant les informations locales successives. Mais, le nombre de degrés de liberté du mouvement en haptique complexifie cette opération, et l'on peut s'interroger sur la représentation de ce mouvement. Il a été observé que l'association sensorimotrice haptique apparaît pouvoir dépasser le cadre de son usage quotidien. Dans le cas de certains dispositifs de substitution sensorielle visuo-tactile, le participant, non-voyant ou bien les yeux bandés, déplace une caméra dont l'image est retransmise tactilement dans le dos grâce à une matrice de vibreurs tactiles. Après un entraînement, les participants rapportent percevoir l'élément filmé, et localisé dans l'espace. Or, il existe deux grandes différences par rapport à une perception tactile usuelle. Tout d'abord, la modification de la stimulation liée au mouvement correspond à une modalité distale, comme la vision, et non proximale comme l'est le toucher. Ensuite, le mouvement est réalisé par une partie du corps, le bras, et la conséquence sensorielle tactile est située sur une autre partie, le dos. Afin d'étudier l'association sensorimotrice dans la perception spatiale haptique, nous avons dû établir une méthodologie permettant de séparer le mouvement réalisé de la stimulation tactile résultante afin qu'ils soient situés à deux endroits distincts sur le corps. Nous avons tout d'abord choisi le cas où la conséquence tactile du mouvement d'une main est stimulée sur l'index de l'autre main. Cette expérience a montré qu'il existait une représentation du mouvement, abstraite de son origine, pouvant être associée avec la stimulation tactile situé sur l'autre main, sans entraînement. L'association sensorimotrice entre les deux bras peut être considérée comme un cas spécifique en raison de la coordination bimanuelle. Nous avons donc étudié cette association lorsque le mouvement est réalisé par le pied ou les yeux ou lorsqu'un point se déplace visuellement sans aucun mouvement du participant. Les résultats ont montré qu'il existe deux représentations complémentaires du mouvement. Une première, plus abstraite, correspondant au codage d'une direction dans l'espace. Elle est utilisée même lorsqu'il n'y a pas d'action mais simplement la visualisation d'un mouvement. L'autre représentation correspond aux caractéristiques du mouvement (amplitude/vitesse) et n'a pu être observé que lorsqu'il y avait une action. L'étude suivante s'est concentrée sur le référentiel de représentation de la direction du mouvement. Les résultats ont montré qu'il s'agissait en partie d'un référentiel centré sur le participant. Dans le cas où les bras étaient positionnés devant et à proximité du participant, présentaient une tendance plus instable voire allocentrique pour certains participants. / The world appears stable to us. It seems to exist independently from our own movements and the sense we use to perceive it. Our movements can however modify the sensory information we receive: the retinal image is constantly modified when we walk as is the tactile stimulation when we move the hand to identify an object. External objects can also move in the meantime, further modifying the stimulation. The knowledge of our own movement in the environment is necessary to distinguish sensory modifications linked to our own action and the ones linked to external movement. In most of the cases, the sensory receptor itself is moved in order to perceive and it generates the sensory modification linked to its movement. Touch is fundamentally an active modality. Explored objects are generally larger than the skin surface used to perceive them. Spatial characteristics of the objects are perceived thanks to the movement, by combining the successive local tactile information, which is made even more complicated by the degrees of freedom inherent to the movement in haptic perception. This leads to the question on how the movement is represented. It has been observed that sensory-motor combination in haptic goes beyond the way it is normally used on a daily basis. Participants -blind or blindfolded- uses visuo-tactile sensory substitution displays by moving a camera. The resulting image is "displayed" tactilely on the back of the participant using a matrix of vibrators. After a period of training, participants report that they perceive the filmed object, located in space. There are two main differences between this experiment and the usual haptic perception. First, the modification of the stimulation linked to the movement corresponds to a distal modality, like vision, and not a proximal modality, like haptic. Then, the movement is made with one part of the body, the arm, and the sensory consequence is perceived on another part of the body, the back. In order to study the sensory-motor association in spatial haptic perception, we have set up a method to divide location of the movement on the body from the location where the resulting tactile consequence is perceived. Our first study was the case of moving one hand and feeling the tactile consequence on the other hand's index finger. This experiment has shown that a representation of the movement, abstract from its location on the body, could be associated to the tactile simulation, without training. Moreover, we have studied this association in the situations where feet or eyes move, or for a seen motion (without any movement of the participant). Results have shown that there are two distinct and complementary representations of the movement. The first one, more abstract, corresponds to the spatial direction. It is used even when there is no action -visual movement-. The other representation corresponds to the movement's characteristics (amplitude/velocity) and hasn't been observed when participants are not moving. In another experiment, we have studied the reference frame of the movement's direction. Results have shown that the main part of the reference frame was egocentric but in the cases where the arms were positioned in front of and near from the participant, the reference frame was instable and even allocentric for some participants.
322

Innovative mixed reality advanced manufacturing environment with haptic feedback

Satterwhite, Jesse C. 13 July 2018 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / In immersive eLearning environments, it has been demonstrated that incorporating haptic feedback improves the software's pedagogical effectiveness. Due to this and recent advancements in virtual reality (VR) and mixed reality (MR) environments, more immersive, authentic, and viable pedagogical tools have been created. However, the advanced manufacturing industry has not fully embraced mixed reality training tools. There is currently a need for effective haptic feedback techniques in advanced manufacturing environments. The MR-AVML, a proposed CNC milling machine training tool, is designed to include two forms of haptic feedback, thereby providing users with a natural and intuitive experience. This experience is achieved by tasking users with running a virtual machine seen through the Microsoft HoloLens and interacting with a physical representation of the machine controller. After conducting a pedagogical study on the environment, it was found that the MR-AVML was 6.06% more effective than a version of the environment with no haptic feedback, and only 1.35% less effective than hands-on training led by an instructor. This shows that the inclusion of haptic feedback in an advanced manufacturing training environment can improve pedagogical effectiveness.
323

Att känna historien : - ett skapande av intresseväckande ingångar för barn

Danielsson, Lovisa January 2021 (has links)
Touching history – to create interesting entrances is a thesis in the field of information design focusing on spatial design. Many museum experiences have been characterized by the gaze. Different barriers in forms of showcases, ropes and exhortations have made the visitor into an observer. With the digitalization this has become even more noticeable. But humans, no matter how young or old, are still physical beings with different senses which offer different ways to experience the world, also in regards of museum experiences. The purpose of this study is to investigate the haptic experience of an object as an information channel in exhibitions. This has been done to investigate if information that is communicated in the interaction between the body and the object has any significance for children’s interest in history.  The scientific theoretical basis for the study focuses, among other things, on the correlation between cognition, emotion and the physical body. This means theories in embodied cognition and haptic perception and previous research about sensory experiences in museums. The purpose for the methodological work has been to thoroughly explore the subject. The work includes interviews through video call, telephone and e-mail with persons working in the museum sector. This to establish the study firmly into the field it aims to explore, and from a museum perspective receive experiences and important inputs. Moreover different workshops and one prototype test have been conducted, this to explore and get an understanding of the subject from the users perspective and to meet their needs. The workshops and the prototype test have been conducted in collaboration with school classes.  With support from theories, previous research and methodological work a design has been created that aims to provide and make haptic experiences available in an exhibition context. This to arouse interest in children, so that the interest works as an entrance in regards to wanting to know more about history. / Att känna historien – ett skapande av intresseväckande ingångar för barn är ett examensarbete inom informationsdesign med inriktning mot rumslig gestaltning. Många museiutställningar har under en tid präglats av visuella intryck, där olika barriärer i form av montrar, rep och förmaningar gjort besökaren till en betraktare. Detta har genom digitaliseringar av museibesök blivit allt mer påtagligt. Samtidigt är människan, gammal som ung, en fysisk varelse med flera sinnen vilka erbjuder en möjlighet att uppleva världen på flera olika sätt, så även med avseende på museibesöket. Studien syftar till att utforska den haptiska upplevelsen av föremål som informationskanal i utställningssammanhang. Detta har gjorts för att undersöka huruvida information som erhålls i samspelet mellan kropp och föremål har betydelse för barns intresse av historia.   Studiens vetenskapliga teoretiska grund fokuserar främst på samspelet mellan kognition, emotion och den fysiska kroppen. Det innebär teorier om förkroppsligad kognition och haptisk perception samt tidigare forskning om betydelsen av sensoriska upplevelser i museisammanhang. Studiens metodiska arbete har syftat till att utforska ämnet från grunden. Arbetet har inbegripit intervjuer via videosamtal, telefon och mejl med personer verksamma inom museisektorn. Detta för att förankra arbetet i det område vilket det avser att utforska och utifrån ett museiperspektiv erhålla erfarenheter och betydelsefulla insikter. Därtill har olika workshops och ett prototyptest genomförts, detta för att utforska och förstå ämnet ur användarens perspektiv och förankra gestalningsförslaget i de behov som föreligger. Genomförande av workshops och prototyptest har skett tillsammans med två skolklasser.   Med stöd i teori och tidigare forskning samt metodiskt arbete har ett gestaltningsförslag för ett utställningsrum arbetats fram som syftar till att tillhandahålla och tillgängliggöra haptiska upplevelser av föremål i utställningssammanhang. Detta för att väcka intresse hos barn, ett intresse som i sin tur är tänkt att fungerar som ingångar till att vilja veta mer om historien.
324

A Variable-Stiffness Compliant Mechanism for Stiffness-Controlled Haptic Interfaces

Hawks, Jeffrey C 01 December 2014 (has links) (PDF)
In this research a variable-stiffness compliant mechanism was developed to generate variable force-displacement profiles at the mechanisms coupler point. The mechanism is based on a compliant Roberts straight-line mechanism, and the stiffness is varied by changing the effective length of the compliant links with an actuated slider. The variable-stiffness mechanism was used in a one-degree-of-freedom haptic interface to demonstrate the effectiveness of varying the stiffness of a compliant mechanism. Unlike traditional haptic interfaces, in which the force is controlled using motors and rigid links, the haptic interface developed in this work displays haptic stiffness via the variable-stiffness compliant mechanism. The force-deflection behavior of the mechanismwas analyzed using the Pseudo-Rigid Body Model (PRBM), and two key parameters, KQ and g,were optimized using finite element analysis (FEA) to match the model with the behavior of the device. One of the key features of the mechanism is that the inherent return-to-zero behavior of the compliant mechanism was used to provide the stiffness feedback felt by the user. A prototype haptic interface was developed capable of simulating the force-displacement profile of Lachmans Test performed on an injured ACL knee. The compliant haptic interface was capable of displaying stiffnesses between 4200 N/m and 7200 N/m.
325

Haptic and visual simulation of material cutting process : a study focused on bone surgery and the use of simulators for education and training

Eriksson, Magnus G. January 2006 (has links)
A prototype of a haptic and virtual reality simulator has been developed for simulation of the bone milling and material removal process occurring in several operations, e.g. temporal bone surgery or dental milling. The milling phase of an operation is difficult, safety critical and very time consuming. Reduction of operation time by only a few percent would in the long run save society large expenses. In order to reduce operation time and to provide surgeons with an invaluable practicing environment, this licentiate thesis discusses the introduction of a simulator system to be used in both surgeon curriculum and in close connection to the actual operations. The virtual reality and haptic feedback topics still constitute a young and unexplored area. It has only been active for about 10-15 years for medical applications. High risk training on real patients and the change from open surgery to endoscopic procedures have enforced the introduction of haptic and virtual reality simulators for training of surgeons. Increased computer power and the similarity to the successful aviation simulators also motivate to start using simulators for training of surgical skills. The research focus has been twofold: 1) To develop a well working VR-system for realistic graphical representation of the skull itself including the changes resulting from milling, and 2) to find an efficient algorithm for haptic feedback to mimic the milling procedure using the volumetric Computer Tomography (CT) data of the skull. The developed haptic algorithm has been verified and tested in the simulator. The visualization of the milling process is rendered at a graphical frame rate of 30 Hz and the haptic rendering loop is updated at 1000 Hz. Test results show that the real-time demands are fulfilled. The visual and haptic implementations have been the two major steps to reach the over all goal with this research project. A survey study is also included where the use of VR and haptic simulators in the surgical curriculum is investigated. The study starts with a historical perspective of the VR and haptic topics and is built up by answering different questions related to this topic and the implementation of simulators at the medical centres. The questions are of general concern for those developing surgical VR and haptic simulators. Suggested future work includes modelling, development and validation of the haptic forces occurring in the milling process and, based on this, implementation in the simulator system. Also, further development of the simulator should be done in close cooperation with surgeons in order to get appropriate feedback for further improvements of the functionality and performance of the simulator. / QC 20101112
326

MAPPING STRATEGIES OF DISTANCE INFORMATION BASED ON CONTINUOUS VIBROTACTILE AMPLITUDE AND FREQUENCY VARIATION - THESIS JOHANNES F. RUESCHEN

Johannes Friedrich Rueschen (14238116) 09 December 2022 (has links)
<p>Our study investigates how different mapping strategies of distance information affect performance in an object exploration task with a teleoperated virtual robot. The task was to find an object inside a backpack using a simulated robotic gripper. A virtual proximity sensor tracked the distance between the tip of the gripper and the object. The distance was conveyed as a vibration pattern on the users index finger. This is the only information that was received to guide the user towards the object. The goal was to locate the hidden object by moving the tip of the gripper as quickly and as closely towards the object as possible without touching it. We implemented three different mapping strategies that utilized continuous frequency and amplitude variations of sinusoidal vibrations to encode distance. The present study provides empirical evidence that the mapping strategy can affect accuracy when approaching an object. We found that linear feedback sensations help to sense the rate of approach. Non- linear feedback perception can provide cues that enable more accurate approximation of the absolute distance. We found that experienced participants could selectively attend to and integrate frequency and intensity cues when both modalities are changed simultaneously. Inexperienced participants were not able to make this distinction and found it difficult to interpret such a signal. They preferred one-dimensional changes.</p>
327

Design, Modeling And Control Of Magnetorheological Fluid-Based Force Feedback Dampers For Telerobotic Systems

Ahmadkhanlou, Farzad 05 September 2008 (has links)
No description available.
328

Synchronized Dining Tangible mediated communication for remote commensality

Komaromi Haque, Judit January 2016 (has links)
This thesis discusses commensality as a significant social activity, that helps to maintain and strengthen social bonds. It also examines the sense of touch as a communication channel, and provides an insight to how it can be used to communicate affect. Touch as contextualized medium and its relevance to interaction design is investigated. Based on studies made in psychology, physiology, sociology and communication it aims to find an answer to the question: ”How may we create togetherness -with the help of an interactive device- between loved ones separated by distance during dining, through remote communication?” In order to meet the objectives of the above question this research followed the Research Through Design methodology, with series of workshops and prototyping sessions.
329

<b>IMPACT OF VARIABILITY OF HAPTIC FEEDBACK IN VIRTUAL REALITY (VR) DURING TASK PERFORMANCE</b>

Nuela Enebechi (18126196) 09 March 2024 (has links)
<p dir="ltr">Task performance is considered an important emphasis in the world of Human-Computer Interaction (HCI). With the emergence of advanced technologies such as Virtual Reality (VR), it is important to understand how individuals are able to utilize this tool for productive task performance. Researchers are continuously exploring how to enhance human performance in a digital space (Wang & Jung, 2011). Prior research has demonstrated the role of integrating haptic feedback into a visual interface, with potential benefits in task performance, as well as increased experiences of presence and awareness while completing HCI tasks. Several research studies have been carried out to investigate ways to optimize human performance and richly uncover factors that affect human performance negatively and positively (Asan et al., 2015). Typically, in a VR setting, three primary senses are engaged: visual, auditory, and tactile (haptic). However, there is a gap in the literature regarding how the availability and intensity of haptic feedback through VR controllers affect users during task performance. This research study seeks to understand the cognitive performance of users in VR when exposed to varying levels of haptic feedback via the VR controllers. Results from this research reveal that participants perceived their performance to be higher and frustration to be lower when they were exposed to moderate and consistent availability and intensity of haptic feedback. To enhance VR’s immersion for users, it is essential to comprehend how to engage the human senses to optimize cognitive performance. Overall, the impact of this research study is to add to an existing body of literature in the domain of haptic feedback for extended reality-based experiences. </p>
330

An Investigation of Auditory Icons and Brake Response Times in a Commercial Truck-Cab Environment

Winters, John 11 June 1998 (has links)
In the driving task, vision, hearing, and the haptic senses are all used by the driver to gather required information. Future Intelligent Transportation Systems components are likely to further increase the volume of information available to or required by the driver, particularly in the case of commercial vehicle operators. The use of alternate modalities to present in-vehicle information is a possible solution to the potential overload of the visual channel. Auditory icons have been shown to improve operator performance and decrease learning and response times, not only in industrial applications, but also as emergency braking warnings. The use of auditory icons in commercial truck cabs has the potential to increase the number of auditory displays that can be distinguished and understood by commercial vehicle operators, and this experiment sought to determine the utility of auditory icons in that situation. Nine auditory icons were evaluated by commercial vehicle operators as they drove an experimental vehicle over public roads. A comparison of the data collected in the truck-cab environment to data collected in a laboratory study on the same auditory icons revealed some differences in the perceived meaning, perceived urgency, and association with the auditory icons' intended meanings between the two conditions. The presence of these differences indicates that driver evaluations of auditory icons can be affected by the environment, and testing should therefore be conducted in a situation that approximates the end-user environment as closely as possible. A comparison of the drivers' brake response times across the three warning conditions (no warning, auditory icon, and soft braking) was also conducted on a closed, secure handling course. Dependent measures included overall brake reaction time and its components, steering response time, time to initial driver action, and categorical measures of driver responses (steering, swerving, braking, and stopping). The results indicated numerically shorter mean response times (on the order of 0.5 seconds for Total Brake Response Time) for the two conditions with warnings, but the differences were not statistically significant. The most likely reason for this lack of significance is the extreme between-subject variability in response times in the no warning condition. An analysis of the response time variance across the three conditions did indicate significantly less variability in operator responses in the two warning conditions. Two of the five dependent measures (Brake Pedal Contact Time and Total Brake Response Time) exhibited significantly reduced variance in the auditory icon warning condition compared to the no warning condition. The soft braking warning condition exhibited significantly reduced variance for four of the dependent measures (Accelerator Reaction Time, Brake Pedal Contact Time, Total Brake Response Time, and First Reaction Time). These results indicate that a soft braking stimulus like that used in this study could potentially prove to be a more effective emergency braking warning than simple auditory warnings alone. / Master of Science

Page generated in 0.0617 seconds