SIMULATION AND COMPUTER-AIDED KINEMATIC DESIGN OF 3-DEGREE-OF-FREEDOMSPHERICAL PARALLEL MANIPULATORS

Parallel robotic manipulators are complex mechanical systems that lead to involved kinematic and dynamic equations. Hence, the design of suc h systems is in general not intuitive, and advanced simulation and des ign tools specialized for this type of architecture are highly desirab le. This article discusses the kinematic simulation and computer-aided design of three-degree-of-freedom spherical parallel manipulators wit h either prismatic or revolute actuators. The kinematic analysis of sp herical parallel manipulators is first reviewed. Solutions for the dir ect and inverse kinematic problems are given, and the expressions for the singularity loci are then introduced. The determination of the wor kspace of this type of manipulator is also addressed. Finally, a compu ter package developed specifically for the CAD of spherical parallel m anipulators is presented. This package allows the interactive analysis of manipulators of arbitrary architecture including the representatio n of the workspace, the representation of singularities, and the graph ic animation of trajectories specified either by the direct or the inv erse kinematic module. It can be used for the design of any spherical parallel three-degree-of-freedom actuated mechanism, which can find ma ny applications in high-performance robotic systems. (C) 1995 John Wil ey & Sons, Inc.