Assembly Mode Change of Spherical 3-RPR Parallel Manipulator

Abstract

In this article, the authors investigate the spherical 3-RPR parallel manipulator, focusing on the feasibility of performing non-singular transitions between different direct kinematic problem solutions. Making use of the kinematic mapping approach, a geometric interpretation of the constraint equations of the robot will be given. Several designs of the manipulator will be studied, analyzing the direct singularity surface of each case in the kinematic image space. It will be shown that a general design of this robot allows assembly mode change, reaching a larger operational workspace. Also, two specific architectures which do not permit performing non-singular transitions will be analyzed.

Keywords:

• Direct kinematic problem
• Kinematic image space
• Nonsingular transition
• Spherical parallel manipulator

ACKNOWLEDGMENTS

The authors wish to acknowledge the financial support received from the Spanish Government through the Ministerio de Educación y Ciencia (Project DPI2011-22955), the European Union (Project FP7-CIP-ICT-PSP-209-3), and the Basque Government through the Dpto. Educ., Univ. e Investig. (Project IT445-10). Mónica Urízar would also like to thank the members of the Unit Geometry and CAD (University Innsbruck) for their support and contribution to this work.

Notes

^#Communicated by M. Ceccarelli and V. Mata