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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.
1

Effective development of haptic devices using a model-based and simulation-driven design approach

Ahmad, Aftab January 2014 (has links)
Virtual reality (VR)-based surgical simulators using haptic devices can increase the effectiveness of surgical training for surgeons when performing surgical procedures in hard tissues such as bones or teeth milling. The realism of virtual surgery through a surgical simulator depends largely on the precision and reliability of the haptic device, which reflects the interaction with the virtual model. The quality of perceptiveness (sensation, force/torque) depends on the design of the haptic device, which presents a complex design space due to its multi-criteria and conflicting character of functional and performance requirements. These requirements include high stiffness, large workspace, high manipulability, small inertia, low friction, high transparency, and cost constraints. This thesis proposes a design methodology to improve the realism of force/torque feedback from the VR-based surgical simulator while fulfilling end-user requirements. The main contributions of this thesis are: 1. The development of a model-based and simulation-driven design methodology, where one starts from an abstract, top-level model that is extended via stepwise refinements and design space exploration into a detailed and integrated systems model that can be physically realized. 2. A methodology for creating an analytical and compact model of the quasi-static stiffness of a haptic device, which considers the stiffness of actuation systems, flexible links and passive joints. 3. A robust design optimization approach to find the optimal numerical values for a set of design parameters to maximize the kinematic, dynamic and kinetostatic performances of a 6-degrees of freedom (DOF) haptic device, while minimizing its sensitivity to variations in manufacturing tolerances and cost, and also satisfying the allowed variations in the performance indices. 4. A cost-effective approach for force/torque feedback control using force/torque estimated through a recursive least squares estimation. 5. A model-based control strategy to increase transparency and fidelity of force/torque feedback from the device by compensating for the natural dynamics of the device, friction in joints, gravity of platform, and elastic deformations. / <p>QC 20140415</p>
2

Model-based design of haptic devices

Aftab, Ahmad January 2012 (has links)
Efficient engineering design and development of high precision and reliable surgical simulators, like haptic devices for surgical training benefits from model-based and simulation driven design. The complexity of the design space, multi-domains, multicriteria requirements and multi-physics character of the behavior of such a product ask for a model based systematic approach for creating and validating compact and computationally efficient simulation models to be used for the design process.The research presented in this thesis describes a model-based design approach towards the design of haptic devices for simulation of surgical procedures, in case of hard tissues such as bone or teeth milling. The proposed approach is applied to a new haptic device based on TAU configuration.The main contributions of this thesis are: Development and verification of kinematic and dynamic models of the TAU haptic device. Multi-objective optimization (MOO) approach for optimum design of the TAU haptic device by optimizing kinematic performance indices, like workspace volume, kinematic isotropy and torque requirement of actuators.  A methodology for creating an analytical and compact model of the quasi-static stiffness of haptic devices, which considers the stiffness of; actuation system;flexible links and passive joints. / QC 20120611
3

Interfaces et capteurs pour une chaine de micro-téléopération / Sensors and devices for a micro-teleoperation system

Weill-Duflos, Antoine 06 July 2017 (has links)
La téléopération ouvre des possibilité nouvelles d'interaction avec le micro-monde. Avec des systèmes adaptés il devient possible de manipuler des éléments aux échelles microscopiques. L'ajout d'un retour haptique apporte une information supplémentaire nécessaire à une interaction naturelle. Cette thèse aborde la problématique de la conception d'une chaîne de téléopération haptique par la conception de ses éléments clefs. La première partie décrit l'optimisation de l'interface haptique à un degré de liberté haute fidelité issue des précédents travaux du laboratoire. Un premier travail augmente la précision des efforts produits. Cette amélioration est liée à une optimisation de la mesure de la vitesse de l'interface à des fréquences d’échantillonnage élevées. Un second point traite de la validation et quantification précise des forces de l'interface. La deuxième partie décrit deux nouveaux capteurs de force conçu spécifiquement pour les interactions avec le micro-monde. Ces fonctionnent sur le même principe de mesure par compensation. Deux approches sont suivies pour augmenter les fréquences des forces mesurable par le capteur. La première s'attache à réduire la masse en concevant un nouveau capteur à l'échelle micrométrique avec des technologies MEMS. Une deuxième approche modifie la conception du capteur et supprime la raideur dans le guidage. La troisième partie décrit la conception d'une nouvelle interface haptique à plusieurs degrés de liberté. Les éléments clefs de sa conception sont l'utilisation d'un palier à air, pour un guidage sans frottement, et de moteurs linéaires à induction, pour une inertie réduite. / Teleoperation opens up new possibilities for interaction with the micro-world. Adequate systems make it possible for human to manipulate elements on microscopic scales. An added haptic feedback provides information crucial for a natural interaction. A bilateral coupling between the subsystems offers the best haptic transparency. This thesis addresses the design of a complete haptic teleoperation chain by focusing on its key elements. Three parts are detailed: The first part describes improvements of the high fidelity one degree of freedom haptic interface designed previously. First, the precision of the forces produced is improved. This improvement is related to the measurement of the motor velocity at high sampling frequencies. Then, the device is precisely caracterized. The second part describes the design of two new force sensors designed specifically for interactions with the micro-world. The forces are measured by compensation. Two approach are observed to expand the frequencies of forces measurable by the sensors. First approach try to reduce the mass, a new sensor on a micrometric scale is built with MEMS technologies. The second approach offer a new design of the sensor. In particular, the stiffness in the guidance is removed. The third part describes the design of a new haptic interface with multiple degrees of freedom. This interface combines the performances of the one degree of freedom interface with a 2D configuration. The key elements of its design are the an air bearing for frictionless guidance and linear induction motors for reduced inertia.
4

Tactile Speech Communication: Design and Evaluation of Haptic Codes for Phonemes with Game-based Learning

Juan S Martinez (6622304) 14 May 2019 (has links)
<div>This thesis research was motivated by the need for increasing speech transmission rates through a phonemic-based tactile speech communication device named TAPS (TActile Phonemic Sleeve). The device consists of a 4-by-6 tactor array worn on</div><div>the forearm that delivers vibrotactile patterns corresponding to English phonemes. Three studies that proceeded this thesis evaluated a coding strategy that mapped 39 English phonemes into vibrotactile patterns. This thesis corresponds to a continuation of the project with improvements summarized in two parts. First, a design and implementation of a training framework based on theories of second language acquisition and game-based learning is developed. A role playing game named Haptos was designed to implement this framework. A pilot study using the first version of the game showed that two participants were able to master a list of 52 words within 45 minutes of game play. Second, an improved set of haptic codes was designed. The design was based on the statistics of spoken English and included an additional set of codes that abbreviate the most frequently co-occurring phonemes in duration. The new set included 39 English phonemes and 10 additional abbreviated symbols. The new codes represent a 24 to 46% increase in word presentation rates. A second version of the Haptos game was implemented to test the new 49 codes in a learning curriculum distributed over multiple days. Eight participants learned the new codes within 6 hours of training and obtained an average score of 84.44% in symbol identification tests with error rates per haptic symbol below 18%. The results demonstrate the feasibility of employing the new codes for future work where the ability to receive longer sequences of phonemes corresponding to phrases and sentences will be trained and tested.</div>
5

Manipulation dans le micro/nanomonde : dispositif haptique préhensile / Micro/nanomanipulation : Micro/nanomanipulation : Haptic device

Nigues, Antoine 06 September 2012 (has links)
Le rayonnement synchrotron et la microscopie à sondes locales (SPM) sont deux des techniques les plus utilisées pour étudier les propriétés physiques et chimiques de nanostructures. Le couplage de ces deux techniques est prometteur pour les nanosciences en leur ouvrant de nouveaux horizons. D'un point de vue expérimental ce couplage est un défi exaltant et a déjà prouvé ses capacités par la combinaison de la Microscopie à Force Atomique (AFM) et de la diffraction de Rayons-X pendant le projet X-tip, qui, grâce au développement d'un microcope à force atomique embarqué sur une lugne de lumière synchrotron a permis l'étude du module de Young de microplots de germanium en procédant simulatanément à son indentation et à son analyse par diffraction. Cependant, cette configuration ne permet pas de manipuler en trois dimensions (3D). Le but ultime, pour notre nano-manipulateur est de manipuler en 3D avec un contrôle permanent des nano-forces exercées sur l'objet sous un faisceau d'analyse (rayon X, LASER). Le premier chapitre s'attarde donc sur les senseurs qui devront rendre compte des interactions à l'échelle nanométrique et permettre la saisie d'un objet individuel. Après un tour d'horizon de différentes techniques de micro/nanomanipulation disponibles à ce jour (micro-préhenseurs mécaniques basés sur la technologie MEMS, pinces optiques, préhenseurs basés sur la microscopie à force atomique conventionnelle) et devant les contraintes qu'implique le couplage d'un tel système avec les expériences synchrotron, le choix des oscillateurs à quartz (Diapason et LER) en tant que senseurs est expliqué. La microscopie à force atomique en générale et le fonctionnement particulier de ces oscillateurs sont décrits. Dans le second chapitre le développement instrumental de notre station de nanomanipulation est détaillé et notamment : Comment mettre en place ce type de résonateurs et la pointe associée pour réaliser à la fois l'imagerie AFM de l'échantillon et la préhension de l'objet? Comment contrôler le positionnement grossier et fin des trois éléments d'une nanomanipulation? Enfin le système haptique ERGOS et son couplage avec notre montage est décrit. Dans le dernier chapitre, deux types d'expériences sont présentés : le premier ne fait intervenir que notre montage piloté classiquement par ordinateur et montre ses capacités à réaliser la préhension d'objets micrométriques de manière contrôlée. Le second fait intervenir le couplage entre notre montage et le système haptique pour réaliser l'exploration rapide d'un échantillon ainsi que la localisation et la reconnaissance de forme d'objet sub-micronique. Ces expériences rendent compte des capacités de ce couplage à transmettre directement à un utilisateur les interactions à l'échelle nanométrique ainsi que la possibilité par l'intermédiaire de cette interface de réaliser des tâches complexes : manipulation sur une surface, reconnaissance de forme, et suivi de contour. / The synchrotron radiation and scanning probe microscopy (SPM) are the (two) most used techniques to study the physical and chimical properties of nanostructures. Coupling these two techniques is promising for the nanosciences by opening news horizons. From an experimental point of view, this coupling is an exciting challenge and has already proven its skills with the combination of Atomic Force Microscopy (AFM) and X-Ray diffraction during the X-tip project, which, thanks to the development of an atomic force microscope embended on a synchrotron beamline, has permitted to study Young's modulus of germanium microplots proceeding simultaneously with its indentation and its diffraction analysis. However, this configuration doesn't permit a three dimension (3D) manipulation. The ultimate goal, for our nano-manipulator, is to manipulate in 3D with a permanent control of nano-forces exerted on the object undcer a scanning beam (X-Ray, laser). The first chapter therefore focuses on the sensors which measure the interactions at a nanometer scale and permit the seizure of an individual object. After an overview of the differents techniques of micro/nano-manipulation available today ( mechanical micro-grippers based on MEMS technology, optic tweezers, grippers based on conventionnal atomic force microscopy), and in front of the constraints implied by the coupling of this kind of system with the synchrotron experiments, the choice of quartz oscillators (Tunning fork and LER) as sensors is explained. The atomic force microscopy in general and the particular behavior of these oscillators is described. In the second chapter, the instrumental development of our nano-manipulation station is detailed and especially : How to implement this type of resonators and the associated tip to achieve both AFM imaging of the sample and gripping of the object ? How to control the coarse and fine positionning of the three elements of a nano-manipulation ? Finally, the haptic system ERGOS et its coupling with our assembly is describe. In the last chapter, two types of experiments are presented : the first involves only our assembly piloted classically with a computer and show its skills in the achievement of gripping of micrometric objects in a controled way. The second involves the coupling between our assembly and the haptic system to achieve the fast exploration of a sample and also the location and shape recognition of sub-micronic objects. These experiments reflect the capacities of this coupling to directly transmit to an user the interactions at a nanometer scale and also the possibility using this interface to achieve complex tasks : manipulation on a surface, shape recognition and contour tracking.
6

Cartesian Force Estimation of a 6-DOF Parallel Haptic Device / Kartesisk kraftuppskattning av en 6-DOF parallellhaptisk enhet

Dong, Fanghong January 2019 (has links)
The haptic device recreates the sense of touch by applying forces to the user. Since the device is “rendering” forces to emulate the physical interaction, the force control is essential for haptic devices. While a dedicated force/torque sensor can close the loop of force control, the additional equipment creates extra moving mass and inertia at the tool center point (TCP). Therefore, estimating the Cartesian force at the TCP has continuously been receiving attention over the past decades. The objective of this thesis project is to develop a real-time force estimation algorithm based on the proportional current-torque relationship with the dynamic modeling of the TAU haptic device. The algorithm can be further used for the force control of the device. The research questions of the thesis are: how to design and develop an algorithm for the TAU that used for Cartesian contact force estimation, how to set up the force estimation test bench and how to evaluate the results of the force estimation algorithm. In order to achieve the force estimation algorithm, a virtual environment is built to simulate the real-time haptic physics. Then an external force/torque sensor is installed at the TCP to get the measurement of the Cartesian force at the TCP. The force estimation algorithm calculates the Cartesian force at the TCP based on the current measurement of the DC motors at the six joints. The estimation result of the Cartesian force at the TCP is then compared with the force/torque sensor measurement to determine if the estimation algorithm is sufficiently accurate. The analysis of the estimation accuracy emphasizes the feasibility of Cartesian force estimation on the TAU haptic device. / En haptikenhet gör det möjligt att förmedla en känsla av kontakt i en virtuell värld genom att skapa krafter som motverkar en rörelse . Hur denna kraft skapas och kontrolleras är av stor vikt för att få den så verklighetstrogen som möjligt. Om man har en kraftsensor kan den användas till att utforma en kraftreglering med återkoppling, men på bekostnad av en ökad massa och tröghet vid användarens hand. Detta har medfört ett ökat intresse under de senaste åren för att på olika sätt försöka uppskatta den kraft som återkopplas till användaren utan att behöva en kraftsensor. Målet för detta examensarbete är att utveckla en algoritm för att uppskatta en kontaktkraft i realtid baserat på antagandet att motormomentet är proportionellt beroende av strömmen. Algoritmen kan sedan användas för att konstruera en sluten reglerloop med kraftåterkoppling för en haptisk enhet. Forskningsfrågorna som behandlas i detta examensarbete är;  hur kan vi utforma en algoritm för estimering av kontaktkrafter för haptikenheten TAU  hur kan vi utforma en experimentell försöksuppställning för mätning av de verkliga kontaktkrafterna från TAU vid kontakt.  hur kan vi använda resultaten från experimenten för utvärdering av algoritmen För testning och utvärdering av algoritmen har en virtuell värld skapats för att efterlikna en simuleringsmiljö som haptikenheten är tänkt att användas i. En kraftsensor har monterats under det verktyg som användaren håller i när enheten används när ett typiskt ingrepp ska övas i en simulator, t.ex. borrning i en tand. Vid experimenten beräknar algoritmen den uppskattade kontaktkraften som användaren känner baserat på den uppmätta strömmen för de sex motorer som aktiveras av kontakten. Dessa beräknade värden har sedan jämförts med de från kraftsensorn uppmätta för att avgör om algoritmen är tillräckligt noggrann. Analysen visar att noggrannheten är tillräckligt bra för att vara en lovande ansats till att användas för kraftuppskattning vid reglering av kontaktkraft för haptikenheten TAU.
7

AN EVALUATION OF THE TRAVELING WAVE ULTRASONIC MOTOR FOR FORCE FEEDBACK APPLICATIONS

Venkatesan, Nishant 01 January 2009 (has links)
The traveling wave ultrasonic motor is considered for use in haptic devices where a certain input-output relation is desired between the applied force and the resulting motion. Historically, DC motors have been the standard choice for this purpose. Owing to its unique characteristics, the ultrasonic motors have been considered an attractive alternative. However, there are some limitations when using the ultrasonic motor for force-feedback applications. In particular, direct torque control is difficult, and the motor can only supply torque in the direction of motion. To accommodate these limitations we developed an indirect control approach. The experimental results demonstrate that the model reference control method was able to approximate a second order spring-damper system.
8

Haptic Device Design

Baser, Ozgur 01 January 2006 (has links) (PDF)
ABSTRACT Haptic devices are used to provide multi-modal data transfer between haptic users and computers in virtual reality applications. They enable humans to take force and tactile feedback from any virtual or remote objects. Haptic devices also facilitate the use of data collected from a real object in the virtual environment. Usage of the haptic devices increase more and more in industrial, educational and medical applications in parallel with development of virtual reality technology. As virtual reality technology requires interdisciplinary study with related to its application areas, it creates a lot of different specific working areas (Haptic interface design, freeform model, surgical operations in virtual environment etc.). Especially, some complex modifications which require hand-working can be performed with the system having great potential in medical applications (Brain surgery without error and operations which require great skill etc.). This is only one of the implementations of haptic devices in digital environment. Aim of this study is to design and manufacture a 7 DOF (degrees of freedom) haptic device which serves the mentioned application areas. All different haptic devices in literature have maximum 6 DOF. The designed 7 DOF haptic device has about 20% extra working space and more flexible working capability compared to the other haptic devices with the similar link lengths and joint limitations. This study is important in terms of the development of haptic devices in the world as well as spreading of haptic devices and its applications in Turkey.
9

Design and implementation of control software libraries for fiber characterization / Design and implementation of control software libraries for fiber characterization

Podivín, Ladislav January 2010 (has links)
Tato práce se zabývá návrhem a implementací dvou konkrétních softwarových modulů, které jsou částí distribuovaného řídícího systému CoSMic. Tento systém je určen pro řízení speciálního zařízení pro charakterizaci papírových vláken. Prvním vyvinutým modulem je HapticFiber, ten má poskytovat rozhraní mezi řídícím systémem a speciálním vstupním zařízením - haptic device. Druhým modulem je ViCo, jehož účelem je poskytnout softwarovou obálku pro uživatelem definovaný algoritmus zpracovaní obrazu. Tento modul musí být připraven splnit určitá časová omezení, proto je nutné, aby běžel v rámci operačním systému reálného času.
10

Design setup for haptic devices for surgery applications / Design av haptisk platform för medicinska kirurgi-simulatorer

El Musleh, Khaled January 2016 (has links)
In a way to help doctors and medical students train on performing difficult surgeries before entering the stressful operating room, DevinSense is developing a generic hardware platform for medical simulation. The system is used together with specific simulation software derived from real patient data and optimized towards the user specifications. The hardware platform will enable training for the operator to develop basic surgical skills effectively without the risk of losing the patients and avoiding the hospital daily contrails. The trainee on the simulator sees the scene displayed in real 3D-stereoscopic mode through a semi-transparent mirror and controls the surgery tools with a 6-DOF force feedback device. Thus, the simulated procedure becomes nearly identical to the real surgery. This project aims to develop a conceptual hardware platform for the medical simulator. The proposed solution should be height adjustable to different users. It must also include additional ergonomic functions such as mobility and suitable for use within the working environment. Accordingly, two conceptual prototypes are manufactured and evaluated. The first conceptual prototype is developed to check if the setup provides a good experience for the users, and to dimension the size of the components and to determine their location to set targets for the second prototype. The resulting product of the second prototype is one leg-lifting column with aluminum profile mounted on the top of it. The semi-transparent mirror, secondary monitor, haptic device and additional components are mounted on the setup to deliver the desired functions. The mechanical development is done using Autodesk Inventor. ANSYS is used to simulate the setups’ stresses and vibrational response to ensure that the system will perform optimally. MATLAB is used for mathematical modeling. The test results of the second prototype were promising where the height can be adjusted for users between 155 cm and 200 cm. Furthermore, the prototype provides stable and stiff design while operating on the simulator as well as transporting it. / För att hjälpa läkare och läkarstudenter att träna på att utföra svåra operationer, utvecklar DevinSense en generisk hårdvaruplattform för medicinska kirurgi-simulatorer. Systemet används för specifika simuleringsprogram som kommer ifrån verkliga patientdata och är optimerad med avseende på användarens specifikation. Hårdvaruplattformen möjliggör utbildning för operatören att utveckla grundläggande kirurgiska färdigheter effektivt utan risk för patienterna. Den som utbildas på simulatorn ser operationssimuleringen som en verkligt 3D-stereoskopisk bild genom en halvgenomskinlig spegel och styr kirurgiverktyget med en 6-DOF haptisk-enhet. Simuleringen kommer att kännas som en riktig operation. Syftet med projektet är att utveckla en prototyp av en haptisk plattform för en medicinsk simulator. Prototypen bör vara justerbar i höjdled för att passa olika användare. Den måste också innefatta ytterligare ergonomiska funktioner som till exempel att vara lätt att transportera. Följaktligen har två prototyper tillverkats och utvärderats. Den första prototypen utvecklades för att kontrollera om den ger en bra upplevelse för användaren, för att dimensionera komponenterna och för att bestämma deras platser. Detta för att sätta upp mål för den slutgiltiga prototypen. Den slutgiltiga prototypen har en linjärenhet som är monterad på en bottenplatta och en aluminiumprofil som är monterad ovanpå linjärenheten. Den halvgenomskinliga spegeln, sekundära bildskärmen, haptiska enheten och ytterligare funktionsenheter har även monterats på aluminiumprofilen. Autodesk Inventor användes för att designa prototypen. ANSYS användes för att analysera spänningar och vibrationsbeteende hos prototypen för att säkerställa att systemet kommer att fungera tillfredställande. MATLAB användes för matematisk modellering. Testresultaten för den andra prototypen blev lovande. Höjden kan justeras för användaren, som är mellan 155 och 200 cm lång, den är stabil när användaren använder haptikenheten och den är även stabil när användaren ska förflytta prototypen till ett annat rum.

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