27 research outputs found

    A Parallel Elastic Haptic Thimble for Wide Bandwidth Cutaneous Feedback.

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    Design of wearable fingertip haptic devices is often a compromise between conflicting features: lightness and compactness, against rich and neat haptic feedback. On one side direct drive actuators (i.e. voice coils) provide a clean haptic feedback with high dynamics, with limited maximum output forces. On the other side mechanical transmissions with reduction can increase output force of micro sized motors, at the cost of slower and often noisy output signals. In this work we present a compact fingertip haptic device based on a parallel elastic mechanism: it merges the output of two differently designed actuators in a single, wide bandwidth haptic feedback. Each actuator is designed with a different role: one for rendering fast, high frequency force components, the other for rendering constant to low frequency components. In the work we present design and implementation of the device, followed by experimental characterization of its performance in terms of frequency response and rendering capabilities

    Rendering of Pressure and Textures Using Wearable Haptics in Immersive VR Environments

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    Haptic systems have only recently started to be designed with wearability in mind. Compact, unobtrusive, inexpensive, easy-to-wear, and lightweight haptic devices enable researchers to provide compelling touch sensations to multiple parts of the body, significantly increasing the applicability of haptics in many fields, such as robotics, rehabilitation, gaming, and immersive systems. In this respect, wearable haptics has a great potential in the fields of virtual and augmented reality. Being able to touch virtual objects in a wearable and unobtrusive way may indeed open new exciting avenues for the fields of haptics and VR. This work presents a novel wearable haptic system for immersive virtual reality experiences. It conveys the sensation of touching objects made of different materials, rendering pressure and texture stimuli through a moving platform and a vibrotactile abbrv-doi-hyperref-narrowmotor. The device is composed of two platforms: one placed on the nail side of the finger and one in contact with the finger pad, connected by three cables. One small servomotor controls the length of the cables, moving the platform towards or away from the fingertip. One voice coil actuator, embedded in the platform, provides vibrotactile stimuli to the user

    Rendering of pressure and textures using wearable haptics in immersive VR environments

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    International audienceHaptic systems have only recently started to be designed with weara-bility in mind. Compact, unobtrusive, inexpensive, easy-to-wear, and lightweight haptic devices enable researchers to provide compelling touch sensations to multiple parts of the body, significantly increasing the applicability of haptics in many fields, such as robotics, rehabilitation , gaming, and immersive systems. In this respect, wearable haptics has a great potential in the fields of virtual and augmented reality. Being able to touch virtual objects in a wearable and unobtrusive way may indeed open new exciting avenues for the fields of haptics and VR. This work presents a novel wearable haptic system for immersive virtual reality experiences. It conveys the sensation of touching objects made of different materials, rendering pressure and texture stimuli through a moving platform and a vibrotactile motor. The device is composed of two platforms: one placed on the nail side of the finger and one in contact with the finger pad, connected by three cables. One small servomotor controls the length of the cables, moving the platform towards or away from the fingertip. One voice coil actuator, embedded in the platform, provides vibrotactile stimuli to the user

    A Review of Non-Invasive Haptic Feedback stimulation Techniques for Upper Extremity Prostheses

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    A sense of touch is essential for amputees to reintegrate into their social and work life. The design of the next generation of the prostheses will have the ability to effectively convey the tactile information between the amputee and the artificial limbs. This work reviews non-invasive haptic feedback stimulation techniques to convey the tactile information from the prosthetic hand to the amputeeñ€ℱs brain. Various types of actuators that been used to stimulate the patientñ€ℱs residual limb for different types of artificial prostheses in previous studies have been reviewed in terms of functionality, effectiveness, wearability and comfort. The non-invasive hybrid feedback stimulation system was found to be better in terms of the stimulus identification rate of the haptic prosthesesñ€ℱ users. It can be conclude that integrating hybrid haptic feedback stimulation system with the upper limb prostheses leads to improving its acceptance among users

    Wearable haptic systems for the fingertip and the hand: taxonomy, review and perspectives

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    In the last decade, we have witnessed a drastic change in the form factor of audio and vision technologies, from heavy and grounded machines to lightweight devices that naturally fit our bodies. However, only recently, haptic systems have started to be designed with wearability in mind. The wearability of haptic systems enables novel forms of communication, cooperation, and integration between humans and machines. Wearable haptic interfaces are capable of communicating with the human wearers during their interaction with the environment they share, in a natural and yet private way. This paper presents a taxonomy and review of wearable haptic systems for the fingertip and the hand, focusing on those systems directly addressing wearability challenges. The paper also discusses the main technological and design challenges for the development of wearable haptic interfaces, and it reports on the future perspectives of the field. Finally, the paper includes two tables summarizing the characteristics and features of the most representative wearable haptic systems for the fingertip and the hand

    Optimization-Based wearable tactile rendering

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    Novel wearable tactile interfaces offer the possibility to simulate tactile interactions with virtual environments directly on our skin. But, unlike kinesthetic interfaces, for which haptic rendering is a well explored problem, they pose new questions about the formulation of the rendering problem. In this work, we propose a formulation of tactile rendering as an optimization problem, which is general for a large family of tactile interfaces. Based on an accurate simulation of contact between a finger model and the virtual environment, we pose tactile rendering as the optimization of the device configuration, such that the contact surface between the device and the actual finger matches as close as possible the contact surface in the virtual environment. We describe the optimization formulation in general terms, and we also demonstrate its implementation on a thimble-like wearable device. We validate the tactile rendering formulation by analyzing its force error, and we show that it outperforms other approaches

    Delivering Expressive And Personalized Fingertip Tactile Cues

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    Wearable haptic devices have seen growing interest in recent years, but providing realistic tactile feedback is not a challenge that is soon to be solved. Daily interactions with physical objects elicit complex sensations at the fingertips. Furthermore, human fingertips exhibit a broad range of physical dimensions and perceptive abilities, adding increased complexity to the task of simulating haptic interactions in a compelling manner. However, as the applications of wearable haptic feedback grow, concerns of wearability and generalizability often persuade tactile device designers to simplify the complexities associated with rendering realistic haptic sensations. As such, wearable devices tend to be optimized for particular uses and average users, rendering only the most salient dimensions of tactile feedback for a given task and assuming all users interpret the feedback in a similar fashion. We propose that providing more realistic haptic feedback will require in-depth examinations of higher-dimensional tactile cues and personalization of these cues for individual users. In this thesis, we aim to provide hardware and software-based solutions for rendering more expressive and personalized tactile cues to the fingertip. We first explore the idea of rendering six-degree-of-freedom (6-DOF) tactile fingertip feedback via a wearable device, such that any possible fingertip interaction with a flat surface can be simulated. We highlight the potential of parallel continuum manipulators (PCMs) to meet the requirements of such a device, and we refine the design of a PCM for providing fingertip tactile cues. We construct a manually actuated prototype to validate the concept, and then continue to develop a motorized version, named the Fingertip Puppeteer, or Fuppeteer for short. Various error reduction techniques are presented, and the resulting device is evaluated by analyzing system responses to step inputs, measuring forces rendered to a biomimetic finger sensor, and comparing intended sensations to perceived sensations of twenty-four participants in a human-subject study. Once the functionality of the Fuppeteer is validated, we begin to explore how the device can be used to broaden our understanding of higher-dimensional tactile feedback. One such application is using the 6-DOF device to simulate different lower-dimensional devices. We evaluate 1-, 3-, and 6-DOF tactile feedback during shape discrimination and mass discrimination in a virtual environment, also comparing to interactions with real objects. Results from 20 naive study participants show that higher-dimensional tactile feedback may indeed allow completion of a wider range of virtual tasks, but that feedback dimensionality surprisingly does not greatly affect the exploratory techniques employed by the user. To address alternative approaches to improving tactile rendering in scenarios where low-dimensional tactile feedback is appropriate, we then explore the idea of personalizing feedback for a particular user. We present two generalizable software-based approaches to personalize an existing data-driven haptic rendering algorithm for fingertips of different sizes. We evaluate our algorithms in the rendering of pre-recorded tactile sensations onto rubber casts of six different fingertips as well as onto the real fingertips of 13 human participants, all via a 3-DOF wearable device. Results show that both personalization approaches significantly reduced force error magnitudes and improved realism ratings

    Design of a wearable fingertip haptic device for remote palpation: Characterisation and interface with a virtual environment

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    © 2018 Tzemanaki, Al, Melhuish and Dogramadzi. This paper presents the development of a wearable Fingertip Haptic Device (FHD) that can provide cutaneous feedback via a Variable Compliance Platform (VCP). The FHD includes an inertial measurement unit, which tracks the motion of the user's finger while its haptic functionality relies on two parameters: pressure in the VCP and its linear displacement towards the fingertip. The combination of these two features results in various conditions of the FHD, which emulate the remote object or surface stiffness properties. Such a device can be used in tele-operation, including virtual reality applications, where rendering the level of stiffness of different physical or virtual materials could provide a more realistic haptic perception to the user. The FHD stiffness representation is characterised in terms of resulting pressure and force applied to the fingertip created through the relationship of the two functional parameters - pressure and displacement of the VCP. The FHD was tested in a series of user studies to assess its potential to create a user perception of the object's variable stiffness. The viability of the FHD as a haptic device has been further confirmed by interfacing the users with a virtual environment. The developed virtual environment task required the users to follow a virtual path, identify objects of different hardness on the path and navigate away from "no-go" zones. The task was performed with and without the use of the variable compliance on the FHD. The results showed improved performance with the presence of the variable compliance provided by the FHD in all assessed categories and particularly in the ability to identify correctly between objects of different hardness

    손끝 햅틱 임ëč„ë„Œ 위한 ì˜ì‚Ź 햅틱의 활용

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    í•™ìœ„ë…ŒëŹž (ì„ì‚Ź)-- 서욞대학ꔐ 대학원 : êž°êł„í•­êł”êł”í•™ë¶€, 2016. 2. 읎동쀀.We propose a novel design of cutaneous fingertip haptic device and approach of integrating pseudo-haptics into our cutaneous haptic device. With 2-DoF cutaneous device, angle-force calibration result is presented for its operation. Then, 3-DoF cutaneous haptic device is designed for more realistic contact feedback in virtual reality (VR). Preliminary result of integrating cutaneous device and hand tracking device for complete wearable haptic interface is also demonstrated. Meanwhile, we explore possible utility of pseudo-haptics for cutaneous fingertip haptic device, whose performance is inherently limited due to the lack of kinesthetic feedback. We experimentally demonstrate that: 1) pseudo-haptics can render virtual stiffness to be more rigid or softer only by modulating visual cueand 2) pseudo-haptics can be used to expand the range of the perceived virtual stiffness to be doubled.Chapter 1 Introduction 1 1.1 Motivation and Objectives 1 1.2 Related Works 3 Chapter 2 Cutaneous Fingertip Haptic Device 6 2.1 2-DoF Cutaneous Haptic Device 6 2.1.1 Design and Specification 6 2.1.2 Angle-Force Calibration 8 2.1.3 Application of 2-DoF Cutaneous Haptic Device 10 2.2 3-DoF Cutaneous Haptic Device 11 2.2.1 Design and Specification 11 2.2.2 Control Design 14 2.2.3 IMU Distortion Offset Calibration 17 2.2.4 Device Validation 20 2.2.5 Integration with Wearable Hand Tracking Interface 21 Chapter 3 Pseudo-Haptics with Cutaneous Haptic Feedback 25 3.1 Limitation of Cutaneous Haptic Device 25 3.2 Application of Pseudo-Haptics Effect 26 Chapter 4 Experimental Study 28 4.1 Experimental Settings 28 4.2 Experiment #1 32 4.3 Experiment #2 34 4.4 Experiment #3 36 4.5 Discussion 38 Chapter 5 Conclusion and Future Work 40 5.1 Conclusion 40 5.2 Future Work 41 Bibliography 42 요앜 50Maste
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