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A novel spherical parallel manipulator: forward position problem, singularity analysis, and isotropy design

Published online by Cambridge University Press:  08 September 2008

Javad Enferadi*
Affiliation:
Department of Mechanical Engineering, Ferdowsi University of Mashhad, Mashhad, Iran.
Alireza Akbarzadeh Tootoonchi
Affiliation:
Department of Mechanical Engineering, Ferdowsi University of Mashhad, Mashhad, Iran.
*
*Corresponding author. E-mail: [email protected]

Summary

In this paper, a novel spherical parallel manipulator and its isotropic design is introduced. This manipulator has good accuracy and relatively a larger workspace which is free of singularities. Utilizing spherical configuration the forward position problem is solved by equivalent angle–axis representation and Bezout's method which leads to a polynomial of degree 8. Two examples are given, one for isotropic and one for nonisotrpoic design. The first case results in eight real solutions, therefore, the polynomial being minimal. Using invariant form, we study acceleration analysis, conditions for singularity and find infinite isotropic structures. Accuracy and workspace analysis are also performed and are shown to have good global conditioning index and relatively large workspace. Using isotropic design and singularity requirements, we show the workspace of isotropic design is free of singularity.

Type
Article
Copyright
Copyright © Cambridge University Press 2008

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