150 research outputs found

    High Frequency Acceleration Feedback Significantly Increases the Realism of Haptically Rendered Textured Surfaces

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    Almost every physical interaction generates high frequency vibrations, especially if one of the objects is a rigid tool. Previous haptics research has hinted that the inclusion or exclusion of these signals plays a key role in the realism of haptically rendered surface textures, but this connection has not been formally investigated until now. This paper presents a human subject study that compares the performance of a variety of surface rendering algorithms for a master-slave teleoperation system; each controller provides the user with a different combination of position and acceleration feedback, and subjects compared the renderings with direct tool-mediated exploration of the real surface. We use analysis of variance to examine quantitative performance metrics and qualitative realism ratings across subjects. The results of this study show that algorithms that include high-frequency acceleration feedback in combination with position feedback achieve significantly higher realism ratings than traditional position feedback alone. Furthermore, we present a frequency-domain metric for quantifying a controller\u27s acceleration feedback performance; given a constant surface stiffness, the median of this metric across subjects was found to have a significant positive correlation with median realism rating

    Hardness Perception Based on Dynamic Stiffness in Tapping

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    A human can judge the hardness of an object based on the damped natural vibration caused by tapping the surface of the object using a fingertip. In this study, we investigated the influence of the dynamic characteristics of vibrations on the hardness perceived by tapping. Subjectively reported hardness values were related to the dynamic stiffness of several objects. The dynamic stiffness, which characterizes the impulsive response of an object, was acquired across the 40–1,000 Hz frequency range for cuboids of 14 types of materials by administering a hammering test. We performed two psychophysical experiments—a ranking task and a magnitude-estimation tasks—wherein participants rated the perceived hardness of each block by tapping it with a finger. We found that the perceptual effect of dynamic stiffness depends on the frequency. Its effect displayed a peak around 300 Hz and decreased or disappeared at higher frequencies, at which human perceptual capabilities are limited. The acquired results help design hardness experienced by products

    A Mechanistic Force Model for Simulating Haptics of Hand-Held Bone Burring Operations

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    The research presented in the thesis is concentrated on developing a mechanistic model to predict the forces experienced during bone burring with application to haptic feedback for virtual reality surgical simulations. This model can be used in haptic devices to provide haptic feedback for virtual reality (VR) surgical simulations. The model is developed based on the understanding of the force profile recorded in the experiments. To determine the force produced under various cutting orientations, experiments are conducted using a surgical burr on a synthetic bone. The total force experienced in bone burring can be understood as a combination of resistive force and vibrational force. The resistive force is calculated using the concept of the specific cutting energy of the bone material. The specific cutting energy (Us) is a concept adopted from the mechanics of grinding. Data from the experiments is used to calibrate the specific cutting energy of the material. The vibrational force is developed as an empirical component of the coupled model. Comparisons between the experimentally measured force data and the force profile predicted by the model show a similar trend. Results confirm that the proposed model is capable of effectively predicting the haptics in bone burring, specifically with the abrasive type of burr

    A Novel Haptic Simulator for Evaluating and Training Salient Force-Based Skills for Laparoscopic Surgery

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    Laparoscopic surgery has evolved from an \u27alternative\u27 surgical technique to currently being considered as a mainstream surgical technique. However, learning this complex technique holds unique challenges to novice surgeons due to their \u27distance\u27 from the surgical site. One of the main challenges in acquiring laparoscopic skills is the acquisition of force-based or haptic skills. The neglect of popular training methods (e.g., the Fundamentals of Laparoscopic Surgery, i.e. FLS, curriculum) in addressing this aspect of skills training has led many medical skills professionals to research new, efficient methods for haptic skills training. The overarching goal of this research was to demonstrate that a set of simple, simulator-based haptic exercises can be developed and used to train users for skilled application of forces with surgical tools. A set of salient or core haptic skills that underlie proficient laparoscopic surgery were identified, based on published time-motion studies. Low-cost, computer-based haptic training simulators were prototyped to simulate each of the identified salient haptic skills. All simulators were tested for construct validity by comparing surgeons\u27 performance on the simulators with the performance of novices with no previous laparoscopic experience. An integrated, \u27core haptic skills\u27 simulator capable of rendering the three validated haptic skills was built. To examine the efficacy of this novel salient haptic skills training simulator, novice participants were tested for training improvements in a detailed study. Results from the study demonstrated that simulator training enabled users to significantly improve force application for all three haptic tasks. Research outcomes from this project could greatly influence surgical skills simulator design, resulting in more efficient training

    Human haptic perception in virtual environments: An investigation of the interrelationship between physical stiffness and perceived roughness.

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    Research in the area of haptics and how we perceive the sensations that come from haptic interaction started almost a century ago, yet there is little fundamental knowledge as to how and whether a change in the physical values of one characteristic can alter the perception of another. The increasing availability of haptic interaction through the development of force-feedback devices opens new possibilities in interaction, allowing for accurate real time change of physical attributes on virtual objects in order to test the haptic perception changes to the human user. An experiment was carried out to ascertain whether a change in the stiffness value would have a noticeable effect on the perceived roughness of a virtual object. Participants were presented with a textured surface and were asked to estimate how rough it felt compared to a standard. What the participants did not know was that the simulated texture on both surfaces remained constant and the only physical attribute changing in every trial was the comparison object’s surface stiffness. The results showed that there is a strong relationship between physical stiffness and perceived roughness that can be accurately described by a power function, and the roughness magnitude estimations of roughness showed an increase with increasing stiffness values. The conclusion is that there are relationships between these parameters, where changes in the physical stiffness of a virtual object can change how rough it is perceived to be in a very clear and predictable way. Extending this study can lead to an investigation on how other physical attributes affects one or more perceived haptic dimensions and subsequently insights can be used for constructing something like a haptic pallet for a haptic display designer, where altering one physical attribute can in turn change a whole array of perceived haptic dimensions in a clear and predictable way

    Haptics: Science, Technology, Applications

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    This open access book constitutes the proceedings of the 13th International Conference on Human Haptic Sensing and Touch Enabled Computer Applications, EuroHaptics 2022, held in Hamburg, Germany, in May 2022. The 36 regular papers included in this book were carefully reviewed and selected from 129 submissions. They were organized in topical sections as follows: haptic science; haptic technology; and haptic applications

    Haptics Rendering and Applications

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    There has been significant progress in haptic technologies but the incorporation of haptics into virtual environments is still in its infancy. A wide range of the new society's human activities including communication, education, art, entertainment, commerce and science would forever change if we learned how to capture, manipulate and reproduce haptic sensory stimuli that are nearly indistinguishable from reality. For the field to move forward, many commercial and technological barriers need to be overcome. By rendering how objects feel through haptic technology, we communicate information that might reflect a desire to speak a physically- based language that has never been explored before. Due to constant improvement in haptics technology and increasing levels of research into and development of haptics-related algorithms, protocols and devices, there is a belief that haptics technology has a promising future

    Haptics: Science, Technology, Applications

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    This open access book constitutes the proceedings of the 12th International Conference on Human Haptic Sensing and Touch Enabled Computer Applications, EuroHaptics 2020, held in Leiden, The Netherlands, in September 2020. The 60 papers presented in this volume were carefully reviewed and selected from 111 submissions. The were organized in topical sections on haptic science, haptic technology, and haptic applications. This year's focus is on accessibility
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