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6-DOF parallel manipulators with better dexterity, rotatability, or singularity-free workspace

Published online by Cambridge University Press:  01 July 2009

K. Y. Tsai*
Affiliation:
Department of Mechanical Engineering, National Taiwan University of Science and Technology, 43 Keelung Road, Section 4, Taipei, Taiwan10672.
T. K. Lee
Affiliation:
Department of Mechanical Engineering, National Taiwan University of Science and Technology, 43 Keelung Road, Section 4, Taipei, Taiwan10672.
*
*Corresponding author. E-mail: kytsai@mail.ntust.edu.tw

Summary

Isotropic manipulators are generally considered as designs with optimum dexterity. Currently, many 6-DOF (degrees-of-freedom) isotropic parallel manipulators can be developed by numerical or analytical methods. At an isotropic configuration, a manipulator is equidistant from its neighboring singular points. The distance, however, can be very small, so an isotropic design might have relatively smaller singularity-free workspace. This paper presents methods to develop traditional 6-DOF parallel manipulators with better dexterity and larger singularity-free workspace. Some fully symmetric nontraditional designs are then proposed. The evaluation of kinematic properties shows that the fully symmetric designs have very good global dexterity, better rotatability, and relatively larger singularity-free workspace. The manipulators are suitable for some special tasks requiring higher precision, better rotatability, or larger workspace.

Type
Article
Copyright
Copyright © Cambridge University Press 2008

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