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

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.

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.

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.

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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.

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).

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.

Haptics is a field of robotics that involves many aspects of engineering, requiring the collaboration of different disciplines like mechanics, electronics, control theory and computer science. Although multi-disciplinarity is an element in common with other robotic application, haptic system has the additional requirement of high performance because of the human perception requirement of 1KHz feedback rate. Such high computing requirement impacts the design of the whole haptic system but it is has particular effects in the design and implementation of haptic rendering algorithms. In the chain of software and hardware components that describe a haptic system the haptic rendering is the element that has the objective of computing the force feedback given the interaction of the user with the device.A variety of haptic rendering algorithms have been proposed in the past for the simulation of three degree of freedom (3DoF) interactions in which a single point touches a complex object as well as 6DoF interactions in which two complex objects interact in multiple points. The use of 3DoF or 6DoF algorithms depends mostly from the type of application and consequently the type of device. For example applications like virtual prototype require 6DoF interaction while many simulation applications have less stringent requirements. Apart the number of degree of freedom haptic rendering algorithms are characterized by the geometrical representation of the objects, by the use of rigid or deformable objects and by the introduction of physical properties of the object surface like friction and texture properties. Given this variety of possibilities and the presence of the human factor in the computation of haptic feedback it is hard to compare different algorithms to asses whether one specific solution performs better than any other previously proposed.The goal of the proposed work is two-fold. First this thesis proposes a framework allowing for more objective comparison of haptic rendering algorithms. Such comparison take into account the perceptual aspect of haptic interaction but tries to remove it from the comparison with the aim of obtaining an objective comparison between algorithms. Second, this thesis proposes a new haptic rendering algorithm for 3DoF interaction and one for 6DoF interaction. The first algorithm for 3DoF interaction provides interaction with rotational friction based on a simulation of the soft finger contact model. The new 6DoF interaction algorithm allows the computation of the haptic feedback of interaction between voxel models.

While haptics, tactile displays, and other topics relating to non-visual user interfaces have been the subject of a variety of research initiatives, little has been done specifically related to those for blind driving. Many automation technologies have been developed for the purpose of assisting and improving the safety of sighted drivers, but to enable a true driving experience without any sense of sight has been an essentially overlooked area of study. Since 2005, the Robotics & Mechanisms Laboratory at Virginia Tech has assumed the task of developing non-visual interfaces for driving through the Blind Driver Challenge®, a project funded by the National Federation of the Blind. The objective here is not to develop a vehicle that will autonomously mobilize blind people, but to develop a vehicle that a blind person can actively and independently operate based on information communicated by non-visual interfaces. This thesis proposes some generalized considerations for the development of non-visual interfaces for driving, using the instructional interfaces developed for the Blind Driver Challenge® as a case study. A model is suggested for the function of blind driving as an open-loop control system, wherein the human is an input/output device. Further, a discussion is presented on the relationship between the bandwidth of information communicated to the driver, the amount of human decision-making involved in blind driving, and the cultivation of driver independence. The considerations proposed here are intended to apply generally to the process of non-visual interface development for driving, enabling efficient concept generation and evaluation. / Master of Science