Haptic cues take on meaning as a function of the context in which they are experienced. In interaction with objects in the physical environment, the context always includes a mechanical contact, at which point force and motion variables can be identified, and across which power may flow. In interaction with objects in a virtual or remote environment, it is not necessary for the contact across which haptic responses are rendered to be the same as the contact at which exploratory actions are applied. In this paper, we ask whether force/motion coupling has a significant impact on manual performance or cognitive load. We conducted an experiment in which n=7 participants attempted, while acting through a teleoperator, to discriminate three objects by their stiffness under two conditions. In one condition physical force/motion coupling was present, in the other it was not. To assess cognitive load, we engaged participants in a simultaneous cognitive task that included a response time measure. Results indicated no difference in manual discrimination performance. After rejecting the datasets of three of our participants based on inconsistent strategy by condition, we observed a small, non-significant trend toward lower cognitive load in the condition with physical coupling. Establishing a robust trend will require additional participants. While results are preliminary, we offer our paradigm as an important direction for new inquiry into the distinctions and interrelationships between information and its presentation in various haptic interface applications. Our work is aimed in particular at developing haptic feedback for use in prosthetic applications.

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Our key motivation is the rehabilitation of individuals recovering from stroke or other neurological insult. The torque exerted by a cable-driven joint is the cross product of the line of action of the cable, known as the moment arm, and its tension. The subject of this article delves into this latter, less-studied quantity associated with torque. The concept of moment arm manipulation of a cable-driven joint is introduced, developed, formalized, and then examined with experiments on a physical, single-joint device. This method of moment arm manipulation, referred to as the moment arm manipulation for remote induction of net effective torque (MARIONET), is found to have distinct advantages that make it feasible for home rehabilitation as well as potential outside of the field.

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We have been developing a grip aid system using air cylinders to assist elderly who have weak grasping force to have daily living activities. The system is small and light weight. In this paper, mechanism to assist thumb, index, and middle fingers using one air cylinder for each finger, is proposed. And also control method of the device using a bending sensor to transfer their will to control the system is developed. Finally much kind of objects are grasped with an assist of the system and the result shows a potential of the system.

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A one-degree-of-freedom set-up driven by pneumatic muscles was designed and built in order to research the applicability of pneumatic artificial muscles in industrial applications, especially in wearable robots such as exoskeletons. The experimental set-up is very non-linear and very difficult to control properly. As a reference, an enhanced PID controller was designed. At the same time, a robust controller H_infin and a sliding-mode controller based on an observer were designed and implemented. After that, a new position controller based on an internal pressure loop for each pneumatic muscle was tuned up. Firstly, this paper presents the experimental set-up and the system’s linear models. After that, it summarizes the enhanced PID controller, H_infin controller and the sliding-mode controller that have been designed. Then, it focuses on the position controller based on the internal pressure loops. Finally, the controllers are compared by means of experimental results.

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This paper describes design of array force display for presentation of hardness distribution in an elastic object. The array force display is composed of an elastic plate and a linear actuator array. It provides a spatially continuous surface on which users can effectively touch virtual objects using any part of their bare hand. The elastic plate is made of rubber and sponge. When the actuator pushes the plate, its hardness increases. The user feels as if hard object is submerged in a soft object. The device is evaluated through experiments for palpation performance

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