This paper presents the development of an arm exoskeleton for displaying a force feedback generated from virtual reality. The developed arm exoskeleton allows the user to obtain the sensation of touch along the joints: wrist, elbow and shoulder. To represent the most realistic touching of virtual object, weight of the device and viscosity of each joint should be compensated. Based on the model derived by Lagrange equation, the model can perform quite well however it is sensitive to model uncertainties of mass and joint friction. A torque disturbance observer for robot manipulator is applied to estimate not only the disturbance at each joint, but also the reaction torque from the user.

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This research aims to develop a portable haptic master hand with 20 degrees of freedom (DOF). Master hands are used as haptic interfaces in master-slave systems. A masterslave system consists of a haptic interface that communicates with a virtual world or an end-effector for tele-operation, such as a robot hand. The thumb and fingers are usually modeled as a serial linkage mechanism with 4 DOF. So far, no 20 DOF master hands are developed that can exert perpendicular forces on the finger phalanges during the complete flexion and extension motion. In this paper, the design and development of a portable 4 DOF haptic interface for the index finger is presented. The concept utilizes a mechanical tape brake at the rolling-link mechanism (RLM) for passive force feedback. The systematic Pahl and Beitz design approach is used as an iterative design method. Important design requirements are; perpendicular forces on the finger phalanges, low friction mechanism, easy to control, no backlash, high backdrivability and lightweight

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One of the key requirements for a Virtual Reality system is the multimodal, real-time interaction between the human operator and a computer simulated and animated environment. This paper investigates problems related particularly to the haptic interaction between the human operator and a virtual environment. The work presented here focuses on two issues: 1) the synthesis of whole-hand kinesthetic feedback, based on the application of forces (torques) on individual phalanges (joints) of the human hand, and 2) the experimental evaluation of this haptic feedback system, in terms of human haptic perception of virtual physical properties (such as the weight of a virtual manipulated object), using psychophysical methods. The proposed kinesthetic feedback methodology is based on the solution of a generalized force distribution problem for the human hand during virtual manipulation tasks. The solution is computationally efficient and has been experimentally implemented using an exoskeleton force-feedback glove. A series of experiments is reported concerning the perception of weight of manipulated virtual objects and the obtained results demonstrate the feasibility of the concept. Issues related to the use of sensory substitution techniques for the application of haptic feedback on the human hand are also discussed.

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Magnetorheological fluid (MRF) is a smart material that has the property of changing its viscosity when exposed to a magnetic field. By placing this fluid into a sealed cylinder with an electromagnet piston as a core, a controllable resistance motion dampener can be created. A novel exoskeleton mechanical power transmission system was designed, utilizing rapid prototype parts, to transmit these resistive forces to the user’s fingertips. A first iteration force feedback glove was developed and tested on human subjects for overall usability. The eventual goal of the system is to provide an alternative force producing system for exercises and rehabilitation. The entire system is lightweight, low power, and easily portable

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Haptic sensation has two complex components; skin (cutaneous) sensing which is mediated by a variety of sensing organs that respond to pressure, vibration, displacement and temperature and kinaesthetic/proprioceptive sensing (muscles and joints) which responds to motions and forces exerted by the interaction of the body with the external environment. Although haptic interaction has been identified as being crucial for many applications, achieving realism in haptic feedback has not been possible due to physical, understanding and modelling problems. This paper explores the sensation of touch from a physiological and technological perspective and shows how this can be combined with an integrated touch/force reflecting system to produce a `realistic’ haptic rendering.

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