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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.
51

Sensory-Motor Integration for Control of Digit Position in Grasping and Manipulation

January 2014 (has links)
abstract: Dexterous manipulation is a representative task that involves sensorimotor integration underlying a fine control of movements. Over the past 30 years, research has provided significant insight, including the control mechanisms of force coordination during manipulation tasks. Successful dexterous manipulation is thought to rely on the ability to integrate the sense of digit position with motor commands responsible for generating digit forces and placement. However, the mechanisms underlying the phenomenon of digit position-force coordination are not well understood. This dissertation addresses this question through three experiments that are based on psychophysics and object lifting tasks. It was found in psychophysics tasks that sensed relative digit position was accurately reproduced when sensorimotor transformations occurred with larger vertical fingertip separations, within the same hand, and at the same hand posture. The results from a follow-up experiment conducted in the same digit position-matching task while generating forces in different directions reveal a biased relative digit position toward the direction of force production. Specifically, subjects reproduced the thumb CoP higher than the index finger CoP when vertical digit forces were directed upward and downward, respectively, and vice versa. It was also found in lifting tasks that the ability to discriminate the relative digit position prior to lifting an object and modulate digit forces to minimize object roll as a function of digit position are robust regardless of whether motor commands for positioning the digits on the object are involved. These results indicate that the erroneous sensorimotor transformations of relative digit position reported here must be compensated during dexterous manipulation by other mechanisms, e.g., visual feedback of fingertip position. Furthermore, predicted sensory consequences derived from the efference copy of voluntary motor commands to generate vertical digit forces may override haptic sensory feedback for the estimation of relative digit position. Lastly, the sensorimotor transformations from haptic feedback to digit force modulation to position appear to be facilitated by motor commands for active digit placement in manipulation. / Dissertation/Thesis / Doctoral Dissertation Kinesiology 2014
52

Smart Clothes as a Tangible User Interface to Affect Human Emotions using Haptic Actuators

Arafsha, Faisal January 2012 (has links)
Affective haptic research is a rapidly growing field. Today, more smart haptic clothes are being studied and implemented which are aimed to effect its users emotionally. However, they have some limitations. This research intends to improve the existing literature and contribute by involving consumers directly in the design of a smart haptic jacket by adding heat, vibration actuators, and by enhancing portability. In this thesis, we are interested in six basic emotions: love, joy, surprise, anger, sadness, and fear. An online survey was designed and conducted on 92 respondents that gave feedback of what it is expected from an affective haptic jacket. The results of this survey assisted in the general design, and the feedback helped to build a prototype. 86% of the respondents expressed interest in the system and are willing to try it when it is ready. A detailed design architecture is provided along with details on the hardware and software used for the implementation. Finally, the prototype was evaluated on 14 participants using the actual prototype haptic jacket based on a QoE comparison between the absence and the presence of haptic actuation. The proposed system showed improvement over a similar system that is designed for the same purpose.
53

Springback Force Considerations in Compliant Haptic Interfaces

Swiss, Dallin R. 01 December 2015 (has links)
This thesis investigates the potential benefits and challenges of using compliant mechanisms in the design of haptic interfaces. The benefits and challenges are presented with an emphasis on their inherent springback behavior and an active compensation approach. Design criteria for compliant mechanism joint candidates are reviewed and several joints are surveyed. Quantitative calculations of axial stiffness and maximum stress for five candidates are presented. Generalized analytical models of springback force and compensation torque are created to simulate the implementation of each joint candidate in a two degree-of-freedom planar pantograph. We use these models in the development and discussion of an analytical approach to predict the motor torques needed to actively compensate for the effects of springback.This approach relies on virtual work analyses of the haptic pantograph to determine the springback forces, compensation torques, haptic workspace, and available haptic force after compensation. A key to estimating the available haptic force is knowing that the force capability is different depending on the local springback force. If a component of the desired haptic force aligns with the springback force, then the two can work together, thus increasing the maximum magnitude of available haptic force beyond the nominal amount. Analytical and experimental results are presented. A detailed method of implementation is given along with a hardware demonstration of active compensation.
54

Perceptual Characterization of a Tactile Display for Live Electronic Music Performance : Designing a Vibrotactile Notification Tool for the CIRMMT Live Electronics Framework (CLEF) / Perceptuell karaktärisering av en taktil display för musik som involverar elektronisk generering och processering av ljud i realtid

Frid, Emma January 2014 (has links)
This study was conducted to assess physical and perceptual properties of a tactile display for a vibrotactile notification system within the CIRMMT Live Electronics Framework (CLEF), a Max-based modular environment for composition and performance of live electronic music. The tactile display was composed of two rotating eccentric mass actuators driven by a PWM signal generated from an Arduino microcontroller. Physical measurements using an accelerometer were carried out in order to estimate intensity and spectral peak frequency as function of duty cycle of the PWM signal. In addition, three user-based studies were conducted to estimate perceptual vibrotactile absolute threshold, differential threshold and temporal differential threshold. Obtained results provided us with precise guidelines that facilitate the design of perceptually robust vibrotactile stimuli for our tactile application. A set of eight simple tactons (vibrotactile icons) was defined, whereafter an absolute identification test was conducted in order to estimate mean tacton recognition rates. Results were promising; mean tacton recognition rate was found to be 74 %. Based on all findings described above, a Max-based prototype used for exploration of tactile stimuli was developed. The prototype contained a library of tactile notification presets to be loaded into CLEF, along with a simple tacton editor for design of customized tactile events. / Syftet med denna studie var att undersöka fysiska och perceptuella egenskaper hos en taktil display som designats för att presentera taktila notifikationssignaler till användare av CIRMMT Live Electronics Framework (CLEF), en Max-baserad modulär miljö för komposition och framförande av musikstycken som involverar Live Electronics. Live Electronics är ett begrepp som innefattar elektronik som används för att generera, processera eller modifiera ljud i realtid. Den taktila display som användes i denna studie var uppbyggd av två roterande excentriska massor, drivna av en pulsbreddsmodulerad signal som genereras av en Arduino mikrokontroller. Accelerometermätningar och tre användarbaserade studier genomfördes för att undersöka följande: intensitet och spektral toppfrekvens som funktion av pulskvot, sensorisk tröskel och intensitetsdiskriminering mellan presenterade stimuli, samt JND i millisekunder för två efterföljande taktila stimuli. Erhållna resultat analyserades varefter riktlinjer för design av perceptuellt robusta signaler för vår taktila display sattes upp. I slutfasen av studien designades åtta taktila signaler, varefter en användarbaserad studie genomfördes för att uppskatta hur lätta dessa signaler var att identifiera. En genomsnittlig identifikationsnivå på 74 % kunde noteras. Baserat på ovan beskrivna resultat utvecklades slutligen en taktil modulprototyp i form av ett bibliotek av fördefinierade taktila stimuli. Denna prototyp inkluderande även en funktion som gav användaren möjlighet att designa och skräddarsy egna taktila signaler.
55

Haptic Affordance: Where affordances and haptics blend: a study in feedback and object recognition

Feld, Adam 14 October 2013 (has links)
No description available.
56

Motorized tensioner systemfor prosthetic hands

Hardell, Felix, Tjomsland, Jonas January 2018 (has links)
Modern research in prosthetic devices and other assistivetechnologies are constantly pushing boundaries. Whilethe technology is impressive, it is still inaccessible for thegreater part of the people in need of it. Advanced devicesare often extremely expensive and require regularly maintenancefrom professionals. Enabling the Future is a globalnetwork of volunteers and was founded to face these problems.They design and 3D-print mechanical prosthetics forpeople in need all over the world.Most of the designs used by Enabling the Future are purelymechanical and do not implement motors. The purposeof this thesis was to take a new approach to the designand construction of low-cost motorized prosthetic hands.By distancing all the electronic components from the hand,including the motor, the project aimed to create a devicecompatible with all current designs of the Enabling the Futurecommunity.To conceptualize this approach a demonstrator was constructedand tested. It utilized a muscle sensor which allowedusers to control the hand by tightening their muscles.The distance between the electronic components andthe prosthetic hand measured approximately one and a halfmeters and still transfered enough force, from the motor tothe hand, to deliver an adequate grip strength. / Modern forskning inom protestillverkning och andrahandikapphjälpmedel gör kontinuerligt stora framsteg. Trotsatt tekniken är imponerade är den fortfarande otillgängligför den största del människor som behöver den. Avanceradehjälpmedel är ofta extremt dyra och kräver kontinuerligtunderhåll från yrkesverksamma. Enabling the Future,ett globalt nätverk av volontärer, grundades för att utmanadessa problem. De konstruerar och tillverkar 3D-skrivnamekaniska proteser för människor med behov över hela världen.De flesta konstruktioner som används av Enabling the Futureär helt mekaniska och använder inga motorer. Syftetmed detta kandidatexamensarbete var att med nya tillvägagångssättkonstruera en billig motoriserad handprotes.Genom att placera all elektronik på en distans från handen,inklusive motorn själv, var tanken att skapa ett systemsom är kompatibelt med de konstruktioner som Enablingthe Future använder.För att förverkliga detta konstruerades en prototyp somtestats. Prototypen använde sig av en muskelsensor somlät användaren kontrollera proteshanden genom att spännasin arm. Distansen mellan de elektriska komponenternaoch protesen var ungefär en och en halv meter, samtidigtsom tillräckligt stor kraft kunde transporteras för att stängahanden med ett tillräckligt grepp.
57

Enhancing Situational Awareness Through Haptics Interaction In Virtual Environment Training Systmes

Hale, Kelly 01 January 2006 (has links)
Virtual environment (VE) technology offers a viable training option for developing knowledge, skills and attitudes (KSA) within domains that have limited live training opportunities due to personnel safety and cost (e.g., live fire exercises). However, to ensure these VE training systems provide effective training and transfer, designers of such systems must ensure that training goals and objectives are clearly defined and VEs are designed to support development of KSAs required. Perhaps the greatest benefit of VE training is its ability to provide a multimodal training experience, where trainees can see, hear and feel their surrounding environment, thus engaging them in training scenarios to further their expertise. This work focused on enhancing situation awareness (SA) within a training VE through appropriate use of multimodal cues. The Multimodal Optimization of Situation Awareness (MOSA) model was developed to identify theoretical benefits of various environmental and individual multimodal cues on SA components. Specific focus was on benefits associated with adding cues that activated the haptic system (i.e., kinesthetic/cutaneous sensory systems) or vestibular system in a VE. An empirical study was completed to evaluate the effectiveness of adding two independent spatialized tactile cues to a Military Operations on Urbanized Terrain (MOUT) VE training system, and how head tracking (i.e., addition of rotational vestibular cues) impacted spatial awareness and performance when tactile cues were added during training. Results showed tactile cues enhanced spatial awareness and performance during both repeated training and within a transfer environment, yet there were costs associated with including two cues together during training, as each cue focused attention on a different aspect of the global task. In addition, the results suggest that spatial awareness benefits from a single point indicator (i.e., spatialized tactile cues) may be impacted by interaction mode, as performance benefits were seen when tactile cues were paired with head tracking. Future research should further examine theoretical benefits outlined in the MOSA model, and further validate that benefits can be realized through appropriate activation of multimodal cues for targeted training objectives during training, near transfer and far transfer (i.e., real world performance).
58

Enabling the Blind to See Gestures

Oliveira, Francisco Carlos De Mattos Brito 02 September 2010 (has links)
Mathematics instruction and discourse typically involve two modes of communication: speech and graphical presentation. For the communication to remain situated, dynamic synchrony must be maintained between the speech and dynamic focus in the graphics. Sighted students use vision for two purposes: access to graphical material and awareness of embodied behavior. This embodiment awareness keeps communication situated with visual material and speech. Our goal is to assist students who are blind or visually impaired (SBVI) in the access to such instruction/communication. We employ the typical approach of sensory replacement for the missing visual sense. Haptic fingertip reading can replace visual material. We want to make the SBVI aware of the deictic gestures performed by the teacher over the graphic in conjunction with speech. We employ a haptic glove interface to facilitate this embodiment awareness. In this research, we address issues from the conception through the design, implementation, evaluation to the effective and successful use of our Haptic Deictic System (HDS) in inclusive classrooms. / Ph. D.
59

Our Third Ear: A Multi-Sensory Experience of Sound

Mills, David Robert 06 July 2016 (has links)
Our Third Ear aims to create a multi-sensory experience by fusing sight, touch, and sound. By creating a means of physically feeling music, listeners can connect with songs, bands, and individual musicians on a profoundly personal level. The potential for unintended applications like learning to play an instrument, broadening the understanding of music for people with hearing impairments, or providing a means of therapy are also exciting prospects. The purpose of this paper is to illustrate the process involved in creating a multi-sensory experience of music from concept to prototype. The culmination of interdisciplinary research and a broad range of creative technologies resulting in a working system. The multi-sensory experience consists of primarily tactile, but also visual responses triggered by music and executed in conjunction with aural music. Tactile investigation involved varied tactile sensations such as vibration, temperature, pressure, proprioception, and touch. Further research questioned the practicality, feasibility, and psychological impacts of using such sensations as well as where on the body such sensations would optimally be received. Visual research involved the visual representation of notes, chords, and sounds, as well as, how music could directly affect visuals in a real time environment. Additional research explored active interaction and passive interaction of visual cues using human computer interfaces. / Master of Fine Arts
60

Soaking Sensual Nakedness: Haptic Bathhouse Explorations

Forsell, Mari Jonel 20 April 2016 (has links)
How can architecture stimulate an increased haptic experience? People with sight lack the everyday immediacy of sensory awareness as compared with people with significant sight impairment. When sight is lost, the mind compensates by heightening the other senses for receiving information. In particular, people who are sight impaired depend on their "somesthesis," or skin sense, for information. In contrast, people who are sighted do not depend on somesthesis to accomplish everyday tasks. Many may go through an entire day without considering their sense of touch. If awareness exists, it is likely through discomfort such as that first barefooted encounter on ice cold tile first thing in the morning or grabbing a burning steering wheel after it baked all day in the hot summer sun. Heschong writes "If sight allows for a three-dimensional world, then each other sense contributes at least one, if not more, additional dimensions." (Heschong, p. 28-29) The sighted rely so heavily on the visual sense for information. They miss many simple tactile encounters along with all their contiguous sensational experiences, constricting the development of these additional dimensions, thus significantly diminishing the depth and complexity of their existence. This is an exploration of touch, a bathhouse, just south of Dupont Circle in the urban fabric of Washington DC. Experiencing a place where the entire body can intimately converge with a building saturated with tactile opportunities, the surprise of stimulating skin-to-surface encounters will remind us of our wonderful somatosensation. How we feel during these sensual unions will add vividness to our lives and a desire to again search for more tactile stimuli feeding our rejuvenated mindfulness. / Master of Architecture

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