Release Time:2019-03-12  Hits:

Indexed by: Journal Article

Date of Publication: 2016-11-01

Journal: MECHANISM AND MACHINE THEORY

Included Journals: Scopus、EI、SCIE

Volume: 105

Page Number: 369-387

ISSN: 0094-114X

Key Words: Asymmetrical spherical parallel manipulator; Motion/force transmission; Transmission wrench screw; Stiffness; Universal joint

Abstract: This paper presents a comparative study of asymmetrical spherical parallel manipulators with respect to motion/force transmission and stiffness. The manipulators adopt a center shaft to both generate a decoupled unlimited-torsion motion and support the mobile platform for high positioning accuracy, where the difference lies in the rotationally/linearly actuated limbs in-parallel. The transmission indices are defined based on the virtual coefficient between the transmission wrench and twist screws for design analysis. Comparison of the manipulators is carried out based on a multi-objective optimization approach, which aims to maximize the workspace of high transmissibility and stiffness over a regular workspace. Performance isocontours are visualized to highlight the advantages/drawbacks among the manipulator counterparts. (C) 2016 Elsevier Ltd. All rights reserved.