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A multi-finger haptic interface for visually impaired people
Abstract
The present paper deals with a novel type of dual point haptic system. The system exploits a novel kind of kinematics to achieve a high isotropy which improves the force rendering. Other features of the system are its high stiffness, high peak forces together with a zero backlash cable based transmission. The device can be used by means of a set of sizeable thimbles by any pairs of user's fingertips. Such a device has been developed within the EU GRAB project, for testing a novel set of application with blind users. Such a project investigates to which extent a purely haptic environment can be employed from users with visual impairments in terms of the effective capabilities of the device to exchange high level information with the users; the real degree of interaction which can be achieved in this type of system; the effective opportunity for the user to profit from the system using just this type of interaction. The basic system concepts, the application environment and the system performances are given in the following.
... To achieve the required manipulation capabilities that allows to handle objects in a large workspace while still having excellent haptic response all over the workspace, we decided to modify and integrate a couple of existing 3-DOF haptic manipulators that were designed for haptic exploration in large workspaces (the GRAB Manipulators, presented in [1]). Figure 2 at left shows a schematics of each arm mechanics. ...
... Input data of the algorithm are the vectors positions ) of the center of gimbals and also the rotation matrices ( of the barrels for the right and left arms; this data are obtained by the direct kinematics of the two arms. The handle frame ΣEE , the barrel frame of left arm Σ3,L and the angular variables of gimbals qi are shown in figure 3. The vector position PEE 0 , with respect to the main reference frame Σ0 , is given by (1) In order to obtain the rotation matrix ...
During the design phase of products and before going into production, it is necessary to verify the presence of
mechanical plays, tolerances, and encumbrances on production mockups. This work introduces a multimodal system
that allows verifying assembly procedures of products in Virtual Reality starting directly from CAD models. Thus
leveraging the costs and speeding up the assessment phase in product design. For this purpose, the design of a novel
6-DOF Haptic device is presented. The achieved performance of the system has been validated in a demonstration
scenario employing state-of-the-art volumetric rendering of interaction forces together with a stereoscopic
visualization setup.
... Such applications are beyond the scope of this paper. The systems that are more likely to be considered haptically-coupled devices are multifinger haptic devices [8,9] while they are representing a grasping force (the same haptic impedance between two fingers) and as long as they share the same control loop. However, some multi-finger systems [10] have a modular design wherein each finger has its own controller, and this paradigm may fall into the category of teleoperated systems, even though they are simulating the same virtual scenario. ...
... As might be expected, if b 1 = b 2 = b, stability condition (11) is equivalent to the previous condition (8) no matter the values of the masses. Otherwise, if b 1 b 2 , we can define a new damping coefficient, b 0 , as follows: ...
This paper deals with the stability analysis of two haptically-coupled devices. It describes how to model this kind of systems and shows how to obtain stable linking impedances. The approach is applied to an experimental setup that consists of a bimanual driving system in which both devices are haptically coupled. Four different cases depending on system dynamics are considered: 1) identical rigid devices, 2) different rigid devices, 3) different devices with vibration modes, and 4) mechanically-linked devices with vibration modes. The theoretical analysis is validated with experiments carried out on a driving simulation platform. The influence of the human operator is also experimentally discussed. Results can be extended to other applications where two haptic devices are used to hold virtual objects.
... In order to induce tremor on a healthy subject, we use a 3 Degrees of Freedom (DoF) desktop haptic interface called GRAB [7]. The system, with its main components, is represented in Fig. 1. ...
... Different possible strategies and devices capable of introducing an artificial tremor on the hand of healthy users were analysed in [8]. Among the possible solutions, the employment of a three DoF haptic interface called GRAB [7] appeared to be the most suitable option. ...
This paper presents a haptic system that is conceived to support the design process of a class of products or services in order to make them more accessible to people affected by hand tremor diseases. The main aim is to foster the designer empathy allowing her/him to directly feel the effect of the impairment in first person. Specifically, a desktop haptic device is employed to induce a programmable hand-tremor, that is typically observed in people affected by some kind of neurological diseases, on healthy subjects (i.e. the designers). The developed tool is based on a wrist-attached haptic interface with a workspace that is comparable to that of the arm of the user. Such device is able to exert controlled forces on the user's wrist and induces a hand-tremor whose frequency and amplitude are correlated with those measured on impaired people. The control of the device is based on a custom trajectory-tracking algorithm that takes as input tremor signals that are acquired on patients using an optical motion tracking system. In this paper, we present the employed haptic system, the structure of the control system and the experimental validation of the controller done through the acquisition of data on six patients affected by Parkinson's disease.
... Avizzano et al. [21,22] modified the GRAB system (a European project), by accumulation of a haptic device and audio commands to enable the visually challenged to explore the 3D world through touch and audio commands help. ...
PurposeDigital media has brought a revolution, making the world a global village. For people who are visually impaired and people with visual and hearing impairment, navigating through the digital world can be as precarious as moving through the real world. To enable them to connect with the digital world, we propose a solution, Haptic Encoded Language Framework (HELF), that uses haptic technology to enable them to write digital text using swiping gestures and understand the text through vibrations.Method
We developed an Android application to present the concept of HELF and evaluate its performance. We tested the application on 13 users (five visually impaired and eight sighted individuals).ResultsThe preliminary exploratory analysis of the proposed framework using the Android application developed reveals encouraging results. Overall, the reading accuracy has been found to be approximately 91%, and the average CPM is found to be 25.7.Conclusion
The volunteering users of the HELF Android application found it useful as a means of using the digital media and recommended its usage as an assistive technology for the visually challenged. The results of their performance of using the application motivate further research and development in the proposed work to make HELF more usable by people who are visually impaired and people with visual and hearing impairment.
... The main aim is to design and develop different tools that provide the simulation of human limb impairments. In some studies, existing devices and strategies have been investigated to induce artificial tremors in healthy users [44,45]. In this study, a novel instrument simulating tremor (IST) based on voice coil actuator (VCA) is proposed (see Fig. 6). ...
Pathological tremor is a common neuromuscular disorder that affects millions of people around the globe. This disease largely affects the quality of activities of daily living such as drinking, eating, and writing, such that patients suffering from pathological tremor often have a problem in self-care. This work presents a wearable elbow exoskeleton for tremor suppression (WEETS), which offers an alternative assistive technology to the conventional treatments based on surgery and drug therapy. The WEETS system uses a novel configuration and controllable rotational semi-active actuator (RSAA) based on magnetorheological fluid to suppress the tremor in the elbow joint. The RSAA is characterized by its compact structure, lightweight and enough output torque (about 3.5 Nm). The performance of the WEETS system is validated with simulations and a series of experiments. The results show that the WEETS has the capability to attenuate the elbow tremor regarding the magnitude of angular velocity and acceleration by 61.55% and 61.68%, respectively. Furthermore, for better evaluation of the WEETS system, an instrument based on voice coil actuator is developed to generate mechanical signals simulating pathological tremors, which is a novel method to show the validation of the exoskeleton system for tremor suppression. Overall, the results from the experimental setup and simulations confirm the effectiveness of WEETS on tremor suppression.
... To achieve the required manipulation capabilities that allows to handle objects in a large workspace while still having excellent haptic response all over the wotkspace, we decided to modify and integrate a couple of existing 3-DOF haptic manipulators that were designed for haptic exploration in large workspaces (the GRAB Manipulators, presented in [1]). Figure 3 shows a schematic of each arm mechanics. ...
During the design phase of products and before going into production, it is necessary to verify the presence of mechanical plays, tolerances, and encumbrances on production mockups. This work introduces a multi-modal system that allows verifying assembly procedures of products in Virtual Reality starting directly from CAD models. Thus leveraging the costs and speeding up the assessment phase in product design. For this purpose, the design of a novel 6-DOF Haptic device is presented. The achieved performance of the system has been validated in a demonstration scenario employing state-of-the-art volumetric rendering of interaction forces together with a stereoscopic visualization setup.
... In the last decade, a lot of research activities have been carried out for building applications and systems for blind and visually impaired people in his work, Levesque, (2005) presents a comprehensive survey of the use of haptics with the blind. A dual point haptic interface within the EU GRAB project has been developed for testing three applications: exploration of chart data, a city map explorer, and a simple adventure game (Avizzano et al., 2003). These applications were developed and demonstrated in a subsequent work (Iglesias et al., 2004). ...
... Concepts for this project look much like the more recent design of the SPIDAR system, described below. The HAVE system in Europe also suggests using a cable device for aiding the blind by providing haptic feedback using a rigid rod within the cables [10]. Another system based on the WireMan has been proposed more recently [204], so wearable haptic devices are of growing interest. ...
This paper presents a survey of cable-driven robotics. The focus is on suspended designs, in which a comprehensive review is provided. Attention is given to both applications as well as theoretical issues that have been investigated. The paper consists of an overview of the different types of cable-driven robots, descriptions of constructed and proposed suspended-cable robot designs for various applications and descriptions on various theoretical topics being pursued.
This chapter will describe some properties of multi-finger haptic interaction and two devices which support it. Multi-finger haptic interaction can involve many contacts with the environment, but can also involve only one contact point when mediated by a tool such as a pen. As multiple fingers interact with the environment, their individual biomechanics and their sensory properties interact to form the net mechano-sensory properties of the interaction. This chapter will look at such interactions in two particular cases, spatially varying stiffness of the pen grasp, and sensory thresholds of multi-finger versus single finger interaction with haptic features. To characterize the stiffness of the pen-like grasp in various directions, we describe experiments in which force steps (randomized in amplitude and direction) were applied to subjects’ pen-like tools in the plane tangential to the tip. From these, the stiffness ellipse could be identified. A dynamical model of the fingers positioned similarly to the user’s grasp was used to predict the stiffness ellipsoids with similar results. The ellipsoids were shown to be a function of the squeezing force with which the subjects performed the grasps. Much of the research on sensitivity and sensory thresholds is based on measurements with a single finger. We developed a multifinger haptic device (MFHD) to allow two high quality degrees of freedom for each of four fingers in a natural pose. With this device we could compare the sensory thresholds between single finger and multiple finger haptic exploration.
This chapter describes an interaction technique wherein web pages are parsed so as to automatically generate a corresponding 3D virtual environment with haptic feedback. The automatically created 3D scene is composed of "hapgets" (haptically-enhanced widgets), which are three dimensional widgets providing a behavior that is analogous to the behavior of the original HTML components but are also enhanced with haptic feedback. Moreover, for each 2D map included in a web page a corresponding multimodal (haptic-aural) map is automatically generated. The proposed interaction technique enables the haptic navigation through the internet as well as the haptic exploration of conventional 2D maps for the visually impaired users. A rendering engine of web pages that was developed according to the proposed interaction technique is also presented.
This paper is a fusion of two independent studies investigating related problems concerning the use of haptic virtual environments for blind people: a study in Sweden using a PHANToM 1.5 A and one in the U.K. using an Impulse Engine 3000. In general, the use of such devices is a most interesting option to provide blind people with information about representations of the 3D world, but the restriction at each moment to only one point of contact between observer and virtual object might decrease their effectiveness. The studies investigated the perception of virtual textures, the identification of virtual objects and the perception of their size and angles. Both sighted (blindfolded in one study) and blind people served as participants. It was found (1) that the PHANToM can effectively render textures in the form of sandpapers and simple 3D geometric forms and (2) that the Impulse Engine can effectively render textures consisting of grooved surfaces, as well as 3D objects, properties of which were, however, judged with some over- or underestimation. When blind and sighted participants' performance was compared differences were found that deserves further attention. In general, the haptic devices studied have demonstrated the great potential of force feedback devices in rendering relatively simple environments, in spite of the restricted ways they allow for exploring the virtual world. The results highly motivate further studies of their effectiveness, especially in more complex contexts.
This paper describe ongoing research investigating how visualizations, especially line-graphs and charts, may be represented by haptics both to understand the structure and the values associated with the graphical realization. Much of the current research has focused mainly on the structure of the line-graph; some more recent work has used sound to depict the value of the curve. There has been limited work on multiple curves and more complex charts, with problems occurring between the crossover points of (say) a curve. We use the PHANToM Haptic interface to feel objects within the virtual world. Our investigations are focusing on a three- stage methodology: a) unguided exploration, where the user may wander and explore the haptic visualization in their own time, b) constrained navigation, where the user's point of interest is constrained to a particular path, but the user can still explore within these constraints, and c) Tours, where the user is completely guided round a predefined path.
An abstract is not available.
This paper presents the virtual reality applications developed for the feasibility study tests of the EU funded IST project ENORASI. ENORASI aims at developing a highly interactive and extensible haptic VR training system that allows visually impaired people, especially those blind from birth, to study and interact with various virtual objects. A number of custom applications have been developed based on the interface provided by the CyberGrasp haptic device. Eight test categories were identified and corresponding tests were developed for each category. Twenty-six blind persons conducted the tests and the evaluation results have shown the degree of acceptance of the technology and the feasibility of the proposed approach.
Taking advantage of its long experience in the field of nuclear teleoperation, the CEA has recently developed Virtuose 3D, a new input device for teleoperation and virtual reality. This device is a 6DOF input / 3DOF output haptic device. It introduces different mechanical ameliorations over the existing ones and exhibits particularly good performances. This article presents its design and specifications.
We have implemented a computer interface that renders synchronized auditory and haptic stimuli with very low (0.5ms) latency. The audio and haptic interface (AHI) includes a Pantograph haptic device that reads position input from a user and renders force output based on this input. We synthesize audio by convolving the force profile generated by user interaction with the impulse response of the virtual surface. Auditory and haptic modes are tightly coupled because we produce both stimuli from the same force profile. We have conducted a user study with the AHI to verify that the 0.5ms system latency lies below the perceptual threshold for detecting separation between auditory and haptic contact events. We discuss future applications of the AHI for further perceptual studies and for synthesizing continuous contact interactions in virtual environments.
Through an investigation of how the performance of people who have normal visual capabilities is affected by unimodal, bimodal,
and trimodal feedback, this research establishes a foundation for presenting effective feedback to enhance the performance
of individuals who have visual impairments. Interfaces that employ multiple feedback modalities, such as auditory, haptic,
and visual, can enhance user performance for individuals with barriers limiting one or more channels of perception, such as
a visual impairment. Results obtained demonstrate the effects of different feedback combinations on mental workload, accuracy,
and performance time. Future, similar studies focused on participants with visual impairments will be grounded in this work.
At the University of Bologna, an interdisciplinary project is
active in order to investigate the possibility of implementing and
testing a robotic system to help the mobility of visually impaired
persons. The adopted solution is based on the conversion of stereo
vision images into virtual “bas-relief” surfaces,
perceivable by the user by means of a suitable (portable) haptic
interface. In the paper, details on the adopted solutions and the
developed prototypes are given as well as the experimental results
obtained so far
GUIs: Design issues for rhe PC-Access rprcm ASSEI' 96
- P Mabilleau
- Touching
Mabilleau P., Touching & hewing. GUIs: Design issues for rhe PC-Access rprcm ASSEI' 96, ACWSIGCAPH. L 2nd Annual ACM Conference an Assistive Teehnolo@es (pp. 2-9). Vancouver