Current Issue : April - June Volume : 2014 Issue Number : 2 Articles : 5 Articles
An obstacle avoidance method of action support 7-DOF manipulators is proposed in this paper.The manipulators are controlled\r\nwith impedance control to follow user�s motions. 7-DOF manipulators are able to avoid obstacles without changing the orbit of the\r\nend-effector because they have kinematic redundancy. A joint rate vector is used to change angular velocity of an arbitrary joint\r\nwith kinematic redundancy. The priority of avoidance is introduced into the proposed method, so that avoidance motions precede\r\nfollow motions when obstacles are close to the manipulators. The usefulness of the proposed method is demonstrated through\r\nobstacle avoidance simulations and experiments...
In the last few years, the number of projects studying the human hand from the robotic point of view has increased rapidly, due\r\nto the growing interest in academic and industrial applications. Nevertheless, the complexity of the human hand given its large\r\nnumber of degrees of freedom (DoF) within a significantly reduced space requires an exhaustive analysis, before proposing any\r\napplications. The aim of this paper is to provide a complete summary of the kinematic and dynamic characteristics of the human\r\nhand as a preliminary step towards the development of hand devices such as prosthetic/robotic hands and exoskeletons imitating\r\nthe human hand shape and functionality. A collection of data and constraints relevant to hand movements is presented, and the\r\ndirect and inverse kinematics are solved for all the fingers as well as the dynamics; anthropometric data and dynamics equations\r\nallow performing simulations to understand the behavior of the finger....
This paper introduces the body weight support gait training system known as the AIRGAIT exoskeleton and delves into the design\r\nand evaluation of its leg orthosis control algorithm. The implementation of the mono- and biarticular pneumatic muscle actuators\r\n(PMAs) as the actuation system was initiated to generate more power and precisely control the leg orthosis. This research proposes\r\na simple paradigm for controlling the mono- and bi-articular actuator movements cocontractively by introducing a cocontraction\r\nmodel. Three tests were performed. The first test involved control of the orthosis with monoarticular actuators alone without a\r\nsubject (WO/S); the second involved control of the orthosis with mono- and bi-articular actuators tested WO/S; and the third\r\ntest involved control of the orthosis with mono- and bi-articular actuators tested with a subject (W/S). Full body weight support\r\n(BWS) was implemented in this study during the test W/S as the load supported by the orthosis was at its maximum capacity.This\r\nassessment will optimize the control system strategy so that the system operates to its full capacity. The results revealed that the\r\nproposed control strategy was able to co-contractively actuate the mono- and bi-articular actuators simultaneously and increase\r\nstiffness at both hip and knee joints....
Many assistive robots for elderly and disabled people have been developed in the past few decades. However, very few of them\r\nbecame commercially available. The major cause of the problem is that the cost-benefit ratio and the risk-benefit ratio of them are\r\nnot good or not known.The evaluation of them should be done in the light of the impacts of assistive technologies on users� whole\r\nlife, both in short-term and long-term. In this paper, we propose a framework of evaluation and design of assistive robots using\r\nICF (International Classification of Functioning, Disability, and Health). The goal of the framework is the realization of the life\r\ndesign and the improvement of the quality of life using assistive technologies. We describe the concept of utilizing ICF in the\r\ndevelopment process of assistive robots, and demonstrate its utility by using some examples of practical application such as the\r\nanalysis of daily living, the design of assistive robots and the evaluation of assistive robots.We also show the issues of using ICF for\r\nfurther development of the framework....
Specificmuscle training is expected to be used for efficient rehabilitation and care prevention. In this paper, we propose algorithms\r\nfor designing a motion path capable of strengthening specific muscles. By using the proposed algorithms, it is possible to design a\r\nmotion path maximizing the activity of an agonist muscle and minimizing that of other muscles. For training, the load is applied\r\nby using a 2-link arm. EMG signal is measured during a training experiment, and the degree ofmuscular revitalization is evaluated\r\nby the amplitude of EMG signal. Finally, the effectiveness of the proposed approach is demonstrated through experiments....
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