Academic literature on the topic 'Haptic Interaction'

This paper proposed the solution of haptic feedback interaction, which can be used for 3D interaction in Virtual Spinal Fixation Surgery System. We frist introduced the traditional Proxy-based Volume Haptics solution, and then proposed the Haptic feedback primitive based on it. There are four Haptic feedback primitive: point, line, plane and direct force. The haptic feedback system developing model is composed by Haptic Rendering and Graphics Rendering. The paper designed interface and classes based on this model, and then implemented the haptic feedback system at last. With this system, we can feel the load carring condition, speed up the virtual operation and provide data analysis more accurately.

Haptic feedback is known to improve 3D interaction in virtual environments but current haptic interfaces remain complex and tailored to desktop interaction. In this paper, we describe an alternative approach called “Elastic-Arm” for incorporating haptic feedback in immersive virtual environments in a simple and cost-effective way. The Elastic-Arm is based on a body-mounted elastic armature that links the user's hand to the body and generates a progressive egocentric force when extending the arm. A variety of designs can be proposed with multiple links attached to various locations on the body in order to simulate different haptic properties and sensations such as different levels of stiffness, weight lifting, and bimanual interaction. Our passive haptic approach can be combined with various 3D interaction techniques and we illustrate the possibilities offered by the Elastic-Arm through several use cases based on well-known techniques such as the Bubble technique, redirected touching, and pseudo-haptics. A user study was conducted which showed the effectiveness of our pseudo-haptic technique as well as the general appreciation of the Elastic-Arm. We believe that the Elastic-Arm could be used in various VR applications which call for mobile haptic feedback or human-scale haptic sensations.

Intermolecular binding underlies every metabolic and regulatory processes of the cell, and the therapeutic and pharmacological properties of drugs. Molecular docking systems model and simulate these interactions in silico and allow us to study the binding process. Haptic-based docking provides an immersive virtual docking environment where the user can interact with and guide the molecules to their binding pose. Moreover, it allows human perception, intuition and knowledge to assist and accelerate the docking process, and reduces incorrect binding poses. Crucial for interactive docking is the real-time calculation of interaction forces. For smooth and accurate haptic exploration and manipulation, force-feedback cues have to be updated at a rate of 1 kHz. Hence, force calculations must be performed within 1ms. To achieve this, modern haptic-based docking approaches often utilize pre-computed force grids and linear interpolation. However, such grids are time-consuming to pre-compute (especially for large molecules), memory hungry, can induce rough force transitions at cell boundaries and cannot be applied to flexible docking. Here we propose an efficient proximity querying method for computing intermolecular forces in real time. Our motivation is the eventual development of a haptic-based docking solution that can model molecular flexibility. Uniquely in a haptics application we use octrees to decompose the 3D search space in order to identify the set of interacting atoms within a cut-off distance. Force calculations are then performed on this set in real time. The implementation constructs the trees dynamically, and computes the interaction forces of large molecular structures (i.e. consisting of thousands of atoms) within haptic refresh rates. We have implemented this method in an immersive, haptic-based, rigid-body, molecular docking application called Haptimol_RD. The user can use the haptic device to orientate the molecules in space, sense the interaction forces on the device, and guide the molecules to their binding pose. Haptimol_RD is designed to run on consumer level hardware, i.e. there is no need for specialized/proprietary hardware.

The last decade has seen significant advances in research on haptics and haptic interfaces. Device performance has improved, and the many commercial devices now available at reasonable prices indicate how haptic research will grow and new applications involving haptics will touch all aspects of daily life. Sophisticated systems require research beyond physical devices, such as modeling the physical properties of virtual objects, human physiology, and haptic evaluation. This special issue focuses on state-of-the-art design and development of haptic interfaces and explores potential applications of this technology and related issues such as tactile display, haptic rendering, physiology, and evaluation methodologies. The 15 papers were selected after a rigorous peer review from around the world and include diverse topics such as haptic device design and technology, tactile display and tactile sensing, collaborative multiuser haptic environments, haptic cognition, haptic rendering, tele-existence and multimodal interaction, and medical and rehabilitation applications. We thank the Editorial Board of JRM Journal for making this special issue possible. We also thank the authors for contributing their fine work and revising their papers for this issue, and extend our thanks and appreciation to the reviewers for their constructive comments and suggestions.

The concept and the use of haptic devices need to be disseminated and they should become familiar among young people. At present haptics are used in many everyday tasks in different fields. Additionally, their use in interaction with virtual reality applications simulating real systems sense of touch will increase the usersâ?? realism and immersion and, consequently, they will contribute to improve the intrinsic knowledge to the simulationsâ?? goals. However, haptics are associated with expensive equipment and usually they offer several degrees of freedom. The objective of this work is to make their cost not much more expensive than a â??specialâ? mouse by offering a low cost solution with just one degree of freedom (1DOF) useful in many simple cases. Additionally, it is also an objective of this work the development of simple virtual reality systems requiring interactions only requiring one degree of freedom. A low cost, single-axis force-feedback haptic device of 1 degree of freedom has been developed. For evaluating the interest of this prototype a â??Spring Constantâ? application was built and used as a demonstrator. The complete system - the haptic interacting with the â??Spring Constantâ? - will be described in the present work.

In this paper, we propose a novel body-based haptic interaction model that simulates the intrinsic physical properties of the tool and virtual objects during the haptic interaction. When tracing the haptic tool interacting with objects, the body-based force evaluation model based on Hertz's contact theory including both frictional and frictionless contacts is developed in our system. Physical properties of different object materials expressed by Poisson's ratio and Young's modulus are involved to simulate the realistic touch perception between the haptic tool and objects. The neighborhood of transmitted force is dynamically determined in relation to the contact load, and a discrete solution method is applied to accelerate the computation rate of realistic haptic interaction. Our experimental results have shown satisfactory performance of the body-based haptic model we have developed while interacting in touch-enabled virtual environments.

Mid-air haptics allow bare-hand tactile stimulation; however, it has a constrained workspace, making it unsuitable for room-scale haptics. We present a novel approach to rendering mid-air haptic sensations in a large rendering volume by turning a static array into a dynamic array following the user's hand. We used a 6DOF robot to drive a haptic ultrasound array over a large 3D space. Our system enables rendering room-scale mid-air experiences while preserving bare-hand interaction, thus, providing tangibility for virtual environments. To evaluate our approach, we performed three evaluations. First, we performed a technical system evaluation, showcasing the feasibility of such a system. Next, we conducted three psychophysical experiments, showing that the motion does not affect the user's perception with high likelihood. Lastly, we explored seven use cases that showcase our system's potential using a user study. We discuss challenges and opportunities in how large-scale mid-air haptics can contribute toward room-scale haptic feedback. Thus, with our system, we contribute to general haptic mid-air feedback on a large scale.

This paper presents some directions on the design, development and creative use of haptic systems for musical composition, performance and digital art creation. This research has been conducted both from an artistic and a technical point of view and its ambition, over the last decade, apart from the artistic outcome, was to introduce the field of haptics to artistic communities based on an open, do it yourself—DIY ethos. The five directions presented here are not in any sense exhaustive and are based principally on a series of collaborative works and more personal open-ended explorations with the medium of haptics and, more specifically, force-feedback interaction. They will be highlighted along with information about the interaction models and their application to artistic works created by the author and other colleagues. Those directions are (i) Haptic Algorithms and Systems; (ii) Performers Intercoupling; (iii) Haptic Interfaces as Part of the Artistic Practice; (iv) Electromechanical Sound Generation; and (v) Media Art and Art Installations. The interdisciplinary field of musical haptics still has a relatively minor position in the sound and music computing research agendas and, more importantly, its artistic dimension is very rarely discussed. The findings of this research aim to indicate and clarify potential research pathways and offer some results on the use of haptics and force-feedback systems in an artistic context.

Abstract Dual-task performance depends on both modalities (e.g., vision, audition, haptics) and task types (spatial or object-based), and the order by which different task types are organized. Previous studies on haptic and especially auditory–haptic attentional blink (AB) are scarce, and the effect of task types and their order have not been fully explored. In this study, 96 participants, divided into four groups of task type combinations, identified auditory or haptic Target 1 (T1) and haptic Target 2 (T2) in rapid series of sounds and forces. We observed a haptic AB (i.e., the accuracy of identifying T2 increased with increasing stimulus onset asynchrony between T1 and T2) in spatial, object-based, and object–spatial tasks, but not in spatial–object task. Changing the modality of an object-based T1 from haptics to audition eliminated the AB, but similar haptic-to-auditory change of the modality of a spatial T1 had no effect on the AB (if it exists). Our findings fill a gap in the literature regarding the auditory–haptic AB, and substantiate the importance of modalities, task types and their order, and the interaction between them. These findings were explained by how the cerebral cortex is organized for processing spatial and object-based information in different modalities.

This chapter sets about to provide the background and orientation needed to set a novice designer on his or her way to bringing haptics successfully into an interactive product. To define appropriate roles for haptic interaction, it is necessary to integrate a basic awareness of human capabilities on one hand and current device technology on the other. Here, I explore this integration by first summarizing the most salient constraints imposed by both humans and hardware. I then proceed to relate perceptual, motor, and attentional capabilities to a selection of emerging application contexts chosen to be relevant to contemporary design trends and opportunities. These include abstract communication and notification, augmentation of graphical user interfaces, expressive control, affective communication, and mobile and handheld computing.

Historically, haptics—all different aspects of the sense of touch and its study—has developed around very technical and scientific inquiries. Despite considerable haptic research advances and the obviousness of haptics in everyday life, this modality remains mostly foreign and unfamiliar to designers. The guiding motif of this research relates to a desire to reverse the situation and have designers designing for and with the haptic sense, for human use and looking beyond technical advances. Consequently, this thesis aims to nurture the development of haptics from a designerly perspective, leading to a new field of activities labeled haptic interaction design. It advances that haptic attributes and characteristics are increasingly part of the qualities that make up the interactions and the experiences we have with objects and the interfaces that surround us, and that these considerations can and ought to be knowingly and explicitly designed by designers. The book encompasses an annotated research through design exploration of the developing field of haptic interaction design, building on a considerable account of self-initiated individual design activities and empirical-style group activities with others. This extensive investigation of designing haptic interactions leads to the Simple Haptics proposition, an approach to ease the discovery and appropriation of haptics by designers. Simple Haptics consists in a simplistic, rustic approach to the design of haptic interactions, and advocates an effervescence of direct perceptual experiences in lieu of technical reverence. Simple Haptics boils down to three main traits: 1) a reliance on sketching in hardware to engage with haptics; 2) a fondness for basic, uncomplicated, and accessible tools and materials for the design of haptic interactions; and 3) a strong focus on experiential and directly experiencable perceptual qualities of haptics.  Ultimately, this thesis offers contributions related to the design of haptic interactions. The main knowledge contribution relates to the massification of haptics, i.e. the intentional realization and appropriation of haptics—with its dimensions and qualities—as a non-visual interaction design material. Methodologically, this work suggests a mixed longitudinal approach to haptics in a form of a well-grounded interplay between personal inquiries and external perspectives. The book also presents design contributions as ways to practically, physically and tangibly access, realize and explore haptic interactions. Globally these contributions help make haptics concrete, graspable, sensible and approachable for designers. The hope is to inspire design researchers, students and practitioners to discover and value haptics as a core component of any interaction design activities.

The integration of haptics into virtual environments has triggered a new era by allowing interaction with virtual objects through force feedback in a number of fields. Medicine has been the field with highest potential benefit through improved realism and immersion. Not only have virtual environments become superior to traditional medical training methods due to cost-efficiency, repeatability, and objective assessment but the idea of surgery rehearsal by using patient specific data has been raised as well. Achieving sufficient realism in haptics has been a significant challenge due to performance requirements. In order to provide a stable and smooth feedback to the user, the update rates of force feedback need to be in the range of 1~kHz, which restricts the solution time for real-time interactive applications. Realism, on the other hand, demands advanced algorithms capable of simulating physical properties. These advanced algorithms have a high computational burden, taking significant amounts of time and their real-time use, therefore, mostly requires simplification of the virtual scene affecting realism. During palpation, information is transferred to the hand from the local neighbourhood of contact. In deformation simulations, it is therefore common to use a multiresolution scheme, where the local region is modelled with a higher resolution than more distant regions, and at higher update rates. This approach saves computational power, however the less elaborate modelling in the more remote regions affects accuracy. This thesis presents a pipeline to analyse the error introduced by multiresolution techniques. The idea is to estimate how simulation parameters lead to different error magnitudes, as a preprocessing step. This information can subsequently be used for monitoring the error in real-time, or for adjusting simulation parameters to keep the error under a desired limit. There is a trade-off between accuracy/error and computation time required. In an ideal situation, this error should be kept under perceivable levels. Levels of perception is a topic that has been surveyed in psychophysics among other aspects of touch. It has been shown that differences smaller than a ratio of a reference signal, such as force or stiffness, cannot be perceived. Evaluating the exact value of this ratio, however, is nontrivial since there are many secondary factors having a significant impact, such as the multimodal input. This thesis presents the analysis of some factors affecting the sense of touch that were shown to have such impact. Effects of exploratory procedures on stiffness perception were examined through user studies, followed by another study indicating the significant effects of stiffness gradient. Medical data, such as MR and CT, has much higher resolution than is practically used for deformable meshes. It has been common practice to model deformation behaviour by a mesh with lower resolution than is used for visual representation. Lastly, this thesis presents an approach to introduce high-resolution information. The proposed algorithm allows for the detection of inhomogeneous structures beneath a surface. This can be applied in situations similar to the diagnosis of tumours by palpation. The approach is independent of mesh structure and resolution, and can be integrated into any proxybased haptic rendering algorithm. This makes the algorithm a complementary choice for deformation simulation.

The haptic exploration of 2-D images is a challenging problem in computer haptics. Research on the topic has primarily been focused on the exploration of maps and curves. This thesis describes the design and implementation of a system for the haptic exploration of photographs. The system builds on various research directions related to assistive technology, computer haptics, and image segmentation. An object-level segmentation hierarchy is generated from the source photograph to be rendered haptically as a contour image at multiple levels-of-detail. A tool for the authoring of object-level hierarchies was developed, as well as an innovative type of user interaction by region selection for accurate and efficient image segmentation. According to an objective benchmark measuring how the new method compares with other interactive image segmentation algorithms shows that our region selection interaction is a viable alternative to marker-based interaction. The hierarchy authoring tool combined with precise algorithms for image segmentation can build contour images of the quality necessary for the images to be understood by touch with our system. The system was evaluated with a user study of 24 sighted participants divided in different groups. The first part of the study had participants explore images using haptics and answer questions about them. The second part of the study asked the participants to identify images visually after haptic exploration. Results show that using a segmentation hierarchy supporting multiple levels-of-detail of the same image is beneficial to haptic exploration. As the system gains maturity, it is our goal to make it available to blind users.

With a spatial haptic interface device and a suitable haptic rendering algorithm, users can explore and modify virtual geometries in three dimensions with the aid of their haptic (touch) sense. Designers of surgery simulators, anatomy exploration tools and applications that involve assembly of complex objects should consider employing this technology. However, in order to know how the technology behaves as a design material, the designer needs to become well acquainted with its material properties. This presents a significant challenge today, since the haptic devices are presented as black boxes, and implementation of advanced rendering algorithms represent highly specialized and time consuming development activities. In addition, it is difficult to imagine what an interface will feel like until it has been fully implemented, and important design trade-offs such as the virtual object's size and stability gets neglected. Traditional user-centered design can be interpreted as that the purpose of the field study phase is to generate a set of specifications for an interface, and only solutions that cover these specifications will be considered in the design phase. The designer might miss opportunities to create solutions that uses e.g. lower cost devices since that might require reinterpretation of the overarching goal of the situation with starting point in the technical possibilities, which is unlikely without significant material knowledge. As an example, a surgery simulator designed in this thesis required a high cost haptic device to render adequate forces on the scale of human teeth, but if the design goal is reinterpreted as creating a tool for learning anatomical differences and surgical steps, an application more suitable for the lower cost haptic devices could be crafted. This solution is as much informed by the haptic material "speaking back to" the designer as by field studies. This licentiate thesis will approach a perspective of spatial haptic interface design that is grounded in contemporary design theory. These theories emphasizes the role of the designer, who is not seen as an objective actor but as someone who has a desire to transform a situation into a preferred one as a service to a client or greater society. It also emphasizes the need for crafting skills in order to innovate, i.e. make designed objects real. Further, it considers aesthetic aspects of a design, which includes the subtle differences in friction as you move the device handle, and overall attractiveness of the device and system. The thesis will cover a number of design cases which will be related to design theory and reflected upon. Particular focus will be placed on the most common class of haptic devices which can give force feedback in three dimensions and give input in six (position and orientation). Forces will be computed and objects deformed by an volume sampling algorithm which will be discussed. Important design properties such as stiffness, have been identified and exposed as a material for design. A tool for tuning these properties interactively has been developed to assist designers to become acquainted with the spatial haptic material and to craft the material for a particular user experience. Looking forward, the thesis suggests the future work of making spatial haptic interfaces more design ready, both in software and hardware. This is proposed to be accomplished through development of toolkits for innovation which encapsulate complexities and exposes design parameters. A particular focus will be placed on enabling crafting with the haptic material whose natural limitations should be seen as suggestions rather than hinders for creating valuable solutions.

QC 20130916

En Réalité Virtuelle (RV), le sens haptique accroît l’immersion d’un utilisateur dans un Environnement Virtuel (EV) avec lequel il interagit en temps réel. Dans cette thèse, nous proposons des approches pour améliorer l’interaction haptique à deux mains avec des EV. Nous abordons d’abord des problèmes avec l’interaction bimanuelle dans des EV avec des interfaces à effecteur unique. Nous proposons une technique d’interaction nommée la double bulle pour l’exploration d’EV avec une combinaison de contrôle en position et en vitesse. Nous présentons aussi une technique de manipulation nommée prise magnétique qui facilite la saisie d’objets virtuels avec des proxys rigides simples. Des modes de contrôle communs sont utilisés pour améliorer la saisie et l’exploration simultanées. Une évaluation utilisateur a été réalisée pour mesurer l’efficacité de ces techniques. Nous nous intéressons ensuite au calcul de surfaces de contact. Nous proposons une technique nommée god-finger pour rendre des surfaces similaires à celles générées par des doigts à partir d’un unique point de contact. Elle est basée sur un simple parcours de la géométrie locale de l’objet en contact, et est donc moins coûteuse que des méthodes de simulation de corps souples. La méthode est adaptée pour l’interaction avec des proxys rigides simples ou plus complexes, ainsi qu’avec des objets rigides ou déformables, y compris avec des surfaces rugueuses. Une méthode de rendu visuel donne un retour à l’utilisateur sur la forme de la surface de contact. Enfin, nous abordons la résolution de contacts durant la manipulation dextre d’objets virtuels avec des doigts souples. Le calcul des mécaniques de contact est amélioré en agrégeant les multiples contraintes de contact concernées. Une méthode de distribution de pression non uniforme sur la surface de contact adapte la réponse lors d’un contact contre des arêtes pointues. Nous utilisons le modèle de frottement de Coulomb- Contensou pour simuler efficacement le frottement en torsion. L’approche est évaluée avec un modèle de main déformable pour de l’interaction en temps réel. Les travaux présentés dans ce manuscrit ouvrent de nouvelles perspectives dans le contexte de l’haptique bimanuelle et de la RV, en permettant une interaction plus naturelle avec des EV plus complexes
In Virtual Reality (VR), the haptic sense increases the immersion of users in a Virtual Environment (VE) with which they interact in real time. In this Ph.D thesis, we propose contributions to improve two-handed interaction in haptics with VEs. We first address issues with bimanual interaction in VEs using haptic devices with single effectors. We propose an interaction technique called double bubble for exploration of VEs through a combination of position and rate control. We also present a manipulation technique called magnetic pinch which facilitates the grasping of virtual objects with simple rigid proxies. Simultaneous grasping and exploration of the VE is enhanced using common control modes. A user evaluation was conducted to assess the efficiency of these techniques. We then focus on improving the computation of contact surfaces. We propose a god-finger method to render finger padlike surfaces from a single contact point. It relies on a simple scan of the local geometry of the object in contact, and is this less costly than soft body simulation methods. The method is adapted for interaction using simple or more complex rigid virtual proxies, and with rigid or deformable objects, including rough surfaces. A visual rendering method provides feedback on the shape of the contact surface. Finally, we address the resolution of contacts during dexterous manipulation of virtual objects through soft fingers. The computation of contact mechanics is improved by aggregating the multiple contact constraints involved. A method for nonuniform pressure distribution over the contact surface adapts the response when touching sharp edges. We use the Coulomb-Contensou friction model to efficiently simulate torsional friction. The approach is evaluated with a deformable hand model for real time interaction. The contributions of this manuscript open novel perspectives in the context of bimanual haptics and VR, allowing more natural interaction with more complex VEs

Consumers evaluate products in the market place using their senses and often form mental representations of product properties. These mental representations have been studied extensively. Imagery has been shown to interact with perception within many perceptual modalities including vision, auditory, olfactory, and motor. This dissertation draws on the vast visual imagery literature to examine imagery in the haptic, or touch, modality. Two studies were undertaken to examine the relationship between haptic imagery and haptic perception The first study is based on studies from cognitive psychology that have used similar methods for examining visual imagery and visual perception. In study 1, sighted and visually impaired participants were asked to evaluate objects haptically, to form a haptic image of that object during a short interval, and then to compare the haptic image to a second object. In Study 2, sighted and visually impaired participants listened to five radio advertisements containing imagery phrases from multiple modalities. After listening to the advertisements, participants were asked to recall the ad content and assess both the ad and the product while haptically evaluating the product in the ad. Though results were mixed and further exploration will be necessary, these studies offer broad implications for consumer use of haptic imagery in shopping environments. The implications for both sighted and blind consumers are discussed.

The present document exposes a different approach for haptic rendering, defined as the simulation of force interactions to reproduce the sensation of surface relief in dense models. Current research shows open issues in timely haptic interaction involving large meshes, with several problems affecting performance and fidelity, and without a dominant technique to treat these issues properly. Relying in pure geometric collisions when rendering highly dense mesh models (hundreds of thousands of triangles) sensibly degrades haptic rates due to the sheer number of collisions that must be tracked between the mesh's faces and a haptic probe. Several bottlenecks were identified in order to enhance haptic performance: software architecture and data structures, collision detection, and accurate rendering of surface relief. To account for overall software architecture and data structures, it was derived a complete component framework for transforming standalone VR applications into full-fledged multi-threaded Collaborative Virtual Reality Environments (CVREs), after characterizing existing implementations into a feature-rich superset. Enhancements include: a scalable arbitrated peer-to-peer topology for scene sharing; multi-threaded components for graphics rendering, user interaction and network communications; a collaborative user interface model for session handling; and interchangeable user roles with multi-camera perspectives, avatar awareness and shared annotations. We validate the framework by converting the existing ALICE VR Navigator into a complete CVRE, showing good performance in collaborative manipulation of complex models. To specifically address collision detection computation, we derive a conformal algebra treatment for collisions among points, segments, areas, and volumes, based on collision detection in conformal R{4,1} (5D) space, and implemented in GPU for faster parallel queries. Results show orders of magnitude time reductions in collisions computations, allowing interactive rates. Finally, the main core of the research is the haptic rendering of surface mesostructure in large meshes. Initially, a method for surface haptic rendering was proposed, using image-based Hybrid Rugosity Mesostructures (HRMs) of per-face heightfield displacements and normalmaps layered on top of a simpler mesh, adding greater surface detail than actually present. Haptic perception is achieved modulating the haptic probe's force response using the HRM coat. A usability testbed framework was built to measure experimental performance with a common set tests, meshes and HRMs. Trial results show the goodness of the proposed technique, rendering accurate 3D surface detail at high sampling rates. This local per-face method is extended into a fast global approach for haptic rendering, building a mesostructure-based atlas of depth/normal textures (HyRMA), computed out of surface differences of the same mesh object at two different resolutions: original and simplified. For each triangle in the simplified mesh, an irregular prism is considered defined by the triangle's vertices and their normals. This prism completely covers the original mesh relief over the triangle. Depth distances and surfaces normals within each prism are warped from object volume space to orthogonal tangent space, by means of a novel and fast method for computing barycentric coordinates at the prism, and storing normals and relief in a sorted atlas. Haptic rendering is effected by colliding the probe against the atlas, and effecting a modulated force response at the haptic probe. The method is validated numerically, statistically and perceptually in user testing controlled trials, achieving accurate haptic sensation of large meshes' fine features at interactive rendering rates, with some minute loss of mesostructure detail.
En aquesta tesi es presenta un novedós enfocament per a la percepció hàptica del relleu de models virtuals complexes mitjançant la simulació de les forces d'interacció entre la superfície i un element de contacte. La proposta contribueix a l'estat de l'art de la recerca en aquesta àrea incrementant l'eficiència i la fidelitat de la interacció hàptica amb grans malles de triangles. La detecció de col·lisions amb malles denses (centenars de milers de triangles) limita la velocitat de resposta hàptica degut al gran nombre d'avaluacions d'intersecció cara-dispositiu hàptic que s'han de realitzar. Es van identificar diferents alternatives per a incrementar el rendiment hàptic: arquitectures de software i estructures de dades específiques, algorismes de detecció de col·lisions i reproducció hàptica de relleu superficial. En aquesta tesi es presenten contribucions en alguns d'aquests aspectes. S'ha proposat una estructura completa de components per a transformar aplicacions de Realitat Virtual en Ambients Col·laboratius de Realitat Virtual (CRVEs) multithread en xarxa. L'arquitectura proposada inclou: una topologia escalable punt a punt per a compartir escenes; components multithread per a visualització gràfica, interacció amb usuaris i comunicació en xarxa; un model d'interfície d'usuari col·laboratiu per a la gestió de sessions; i rols intercanviables de l'usuari amb perspectives de múltiples càmeres, presència d'avatars i anotacions compartides. L'estructura s'ha validat convertint el navegador ALICE en un CVRE completament funcional, mostrant un bon rendiment en la manipulació col·laborativa de models complexes. Per a incrementar l'eficiència del càlcul de col·lisions, s'ha proposat un algorisme que treballa en un espai conforme R{4,1} (5D) que permet detectar col·lisions entre punts, segments, triangles i volums. Aquest algorisme s'ha implementat en GPU per obtenir una execució paral·lela més ràpida. Els resultats mostren reduccions en el temps de càlcul de col·lisions permetent interactivitat. Per a la percepció hàptica de malles complexes que modelen objectes rugosos, s'han proposat diferents algorismes i estructures de dades. Les denominades Mesoestructures Híbrides de Rugositat (HRM) permeten substituir els detalls geomètrics d'una cara (rugositats) per dues textures: de normals i d'alçades. La percepció hàptica s'aconsegueix modulant la força de resposta entre el dispositiu hàptic i la HRM. Els tests per avaluar experimentalment l'eficiència del càlcul de col·lisions i la percepció hàptica utilitzant HRM respecte a modelar les rugositats amb geometria, van mostrar que la tècnica proposada va ser encertada, permetent percebre detalls 3D correctes a altes tases de mostreig. El mètode es va estendre per a representar rugositats d'objectes. Es proposa substituir l'objecte per un model simplificat i un atles de mesoestructures en el que s'usen textures de normals i de relleus (HyRMA). Aquest atles s'obté a partir de la diferència en el detall de la superfície entre dos malles del mateix objecte: l'original i la simplificada. A partir d'un triangle de la malla simplificada es construeix un prisma, definit pels vèrtexs del triangle i les seves normals, que engloba el relleu de la malla original sobre el triangle. Les alçades i normals dins del prisma es transformen des de l'espai de volum a l'espai ortogonal tangent, amb mètode novedós i eficient que calcula les coordenades baricèntriques relatives al prisma, per a guardar el mapa de textures transformat en un atles ordenat. La percepció hàptica s'assoleix detectant les col·lisions entre el dispositiu hàptic i l'atles, i modulant la força de resposta d'acord al resultat de la col·lisió. El mètode s'ha validat numèricament, estadística i perceptual en tests amb usuaris, aconseguint una correcta i interactiva sensació tàctil dels objectes simulats mitjançant la mesoestructura de les malles
En esta tesis se presenta un enfoque novedoso para la percepción háptica del relieve de modelos virtuales complejos mediante la simulación de las fuerzas de interacción entre la superficie y un elemento de contacto. La propuesta contribuye al estado del arte de investigación en este área incrementando la eficiencia y fidelidad de interacción háptica con grandes mallas de triángulos. La detección de colisiones con mallas geométricas densas (cientos de miles de triángulos) limita la velocidad de respuesta háptica debido al elevado número de evaluaciones de intersección cara-dispositivo háptico que deben realizarse. Se identificaron diferentes alternativas para incrementar el rendimiento háptico: arquitecturas de software y estructuras de datos específicas, algoritmos de detección de colisiones y reproducción háptica de relieve superficial. En esta tesis se presentan contribuciones en algunos de estos aspectos. Se ha propuesto una estructura completa de componentes para transformar aplicaciones aisladas de Realidad Virtual en Ambientes Colaborativos de Realidad Virtual (CRVEs) multithread en red. La arquitectura propuesta incluye: una topología escalable punto a punto para compartir escenas; componentes multithread para visualización gráfica, interacción con usuarios y comunicación en red; un modelo de interfaz de usuario colaborativo para la gestión de sesiones; y roles intercambiables del usuario con perspectivas de múltiples cámaras, presencia de avatares y anotaciones compartidas. La estructura se ha validado convirtiendo el navegador ALICE en un CVRE completamente funcional, mostrando un buen rendimiento en la manipulación colaborativa de modelos complejos. Para incrementar la eficiencia del cálculo de colisiones, se ha propuesto un algoritmo que trabaja en un espacio conforme R4,1 (5D) que permite detectar colisiones entre puntos, segmentos, triángulos y volúmenes. Este algoritmo se ha implementado en GPU a efectos de obtener una ejecución paralelamás rápida. Los resultadosmuestran reducciones en el tiempo de cálculo de colisiones permitiendo respuesta interactiva. Para la percepción háptica de mallas complejas que modelan objetos rugosos, se han propuesto diferentes algoritmos y estructuras de datos. Las denominadasMesoestructuras Híbridas de Rugosidad (HRM) permiten substituir los detalles geométricos de una cara (rugosidades) por una textura de normales y otra de alturas. La percepción háptica se consigue modulando la fuerza de respuesta entre el dispositivo háptico y la HRM. Los tests realizados para evaluar experimentalmente la eficiencia del cálculo de colisiones y la percepción háptica utilizando HRM respecto a modelar las rugosidades con geometría, mostraron que la técnica propuesta fue acertada, permitiendo percibir detalles 3D correctos a altas tasas de muestreo. Este método anterior es extendido a un procedimiento global para representar rugosidades de objetos. Para hacerlo se propone sustituir el objeto por un modelo simplificado y un atlas de mesostructuras usando texturas de normales y relieves (HyRMA). Este atlas se obtiene de la diferencia en detalle de superficie entre dos mallas del mismo objeto: la original y la simplificada. A partir de un triángulo de la malla simplificada se construye un prisma definido por los vértices del triángulo a lo largo de sus normales, que engloba completamente el relieve de la malla original sobre este triángulo. Las alturas y normales dentro de cada prisma se transforman del espacio de volumen al espacio ortoganal tangente, usando un método novedoso y eficiente que calcula las coordenadas baricéntricas relativas a cada prisma para guardar el mapa de texturas transformado en un atlas ordenado. La percepción háptica se consigue detectando directamente las colisiones entre el dispositivo háptico y el atlas, y modulando la fuerza de respuesta de acuerdo al resultado de la colisión. El procedmiento se ha validado numérica, estadística y perceptualmente en ensayos con usuarios, consiguiendo a tasas interactivas la correcta sensación táctil de los objetos simulados mediante la mesoestructura de las mallas, con alguna pérdida muy puntual de detalle

As a solution to mid-air haptic actuation with strong and continuous tactile force, Magnetic Rendering is presented as an intuitive haptic display method applying an electromagnet array to produce a magnetic field in mid-air where the force field can be felt as magnetic repulsive force exerted on the hand through the attached magnet discs. The magnetic field is generated by a specifically designed electromagnet array driven by direct current. By attaching small magnet discs on the hand, the tactile sensation can be perceived by the user. This method can provide a strong tactile force on multiple points covering user’s hand and avoid cumbersome attachments with wires, thus it is suitable for a co-located visual and haptic display. In my work, the detailed design of the electromagnet array for haptic rendering purposes is introduced, which is modelled and tested using Finite Element Method simulations. The model is characterized mathematically, and three methods for controlling the magnetic field are applied accordingly: direct control, system identification and adaptive control. The performance of the simulated model is evaluated in terms of magnetic field distribution, force strength, operation distance and force stiffness. The control algorithms are implemented and tested on a 3-by-3 and a 15-by-15 model, respectively. Simulations are performed on a 15-by-15 model to generate a haptic human face, which results in a smooth force field and accurate force exertion on the control points.

AbstractThis chapter serves as an introduction and motivation for the field of haptic research. It provides an overview of the technical domains covered, but also introduces the philosophical and social aspects of human haptic sense. Various definitions of haptics as a perceptual and interaction modality are discussed to serve as a common ground for the rest of the book. Typical application areas such as telepresence, training, interaction with virtual environments and communication are introduced and typical haptic systems from these areas are discussed.

AbstractThis chapter deals with different interface technologies that can be used to connect task-specific haptic systems to an IT system. Based on an analysis of the relevant bandwidth for haptic interaction depending on the intended application and an introduction of several concepts to reduce the bandwidth for these application (local haptic models, event-based haptics, movement extrapolation etc.), several standard interfaces are evaluated for the use in haptic systems.

Haptic communication offers many interesting opportunities such as an unparalleled feel of presence, opening up to emotions and assuring oneself in reality - except for adding to perception of sizes, distances, weight, hardness, softness, warmth, and coldness – all fundamental aspects of the world. Haptic senses (cutaneous, kinaesthesis etc.) are found all over the body which also means that any technological means, such as wearables have/should have the same potential of full body coverage. For haptics, proximal stimulus could be located at two (or more) spatial separated anatomical locations simultaneously. As any proximal stimulus is an event and events have a duration i.e. existing in temporal space, it is of interest to see how events relate to each other. We do this first for two events, where we get an exact number, and then try to generalize this to three and more events. We observe that natural languages typically lack the fine distinctions in their vocabulary, relaying on vague (as we show) expressions like “before” and “after”.

Abstract A haptic simulation environment to simulate planar three-degree-of-freedom motion has been developed by the authors. The system consists of a novel parallel manipulandum and associated control, collision detection and dynamic simulation software running on a QNX PC. This paper describes haptic interface control and outlines the control systems that have been designed for the haptic rendering of virtual environments. Virtual environment design and implementation are also discussed. Using the haptic simulation environment that has been developed, a four-channel teleoperation architecture is shown to be an effective means to display a variety of simulated environments and is compared with a popular impedance-based approach.