Kinematic design of a translational parallel mechanism based on sub-kinematic chain determined workspace superposition

Abstract

This paper presents the kinematic design of a translational parallel mechanism (PM) named Vari-Orthoglide by means of the workspace superposition, according to the sub-kinematic chain (SKC) based PM composition principle. The main topological characteristics of the manipulator with two SKCs under study, such as the position and orientation (POC) characteristics, degree of freedom (DOF) and coupling degree are analyzed, which turns out that the coupling degree equals to 1, implying the partially decoupled motion. With the topological characteristics based kinematic modeling principle, a symbolic model of the kinematics is established to derive its symbolic direct and inverse kinematic solutions. Based upon the direct kinematic solution, the workspaces for the two SKCs can be efficiently found. Moreover, the singularity loci are identified for finding the singularity-free workspace, where a regular workspace is fitted as the task workspace as expected. The presented work shows an approach to design translational parallel mechanisms considering motion decoupling and regular workspace, applicable to other types of parallel mechanisms.

Design and Kinematic Analysis of a Novel Planar Parallel Robot With Pure Translations

“…A systematic design of a group of novel parallel architectures is the primary step in robotics. There are four main type synthesis methodologies: generalized function set theory, single open chain approach, the theory of screw, Lie group and Lie algebra [10][11][12][13][14]. The screw theory has been utilized in many research.…”