Title: Design and control of a parallel robot for ankle rehabilitation

Authors: Y.H. Tsoi, S.Q. Xie

Addresses: Department of Mechanical Engineering, University of Auckland, New Zealand. ' Department of Mechanical Engineering, University of Auckland, New Zealand

Abstract: The use of robots in rehabilitation, particularly for physical therapy has the potential to bring about various benefits including reduction of physical workload of physiotherapists and improved repeatability. A three degree of freedom parallel robot is proposed in this paper to accommodate range of motion (ROM) and muscle strengthening exercises for ankle rehabilitation. Singularity analysis of the design revealed that a redundantly actuated robot is required to avoid singularity in the workspace. Kinematic parameters of the robot were selected so that the available workspace could closely match the available ankle ROM. An impedance control scheme has been utilised to allow control of both force and motion to ensure safety of the patient. The redundant actuation degree of freedom is exploited to regulate the vertical reaction force at the ankle.

Keywords: rehabilitation robots; parallel robots; singularity analysis; workspace analysis; redundant actuation; impedance control; ankle rehabilitation; robot control; physical therapy; range of motion; muscle strengthening; robot kinematics; force control; motion control; patient safety.

DOI: 10.1504/IJISTA.2010.030193

International Journal of Intelligent Systems Technologies and Applications, 2010 Vol.8 No.1/2/3/4, pp.100 - 113

Available online: 11 Dec 2009 *

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