Position, velocity, and workspace analysis of a novel 6-DOF parallel manipulator with “piercing” rods

Abstract

The article deals with the research of a novel parallel manipulator with six degrees of freedom and three kinematic chains. Each chain of the manipulator presents a so-called “piercing” rod, which injects into the mechanism working area. The paper starts with a mechanism description and its potential applications, followed by a mobility analysis based on screw theory. After that, the positioning analysis, including algorithms to solve inverse and forward kinematics problems, is performed. The paper considers several approaches to solve the forward kinematics problem. The velocity analysis follows next and provides a relation between the output link velocities and the drive speeds. The workspace analysis continues the kinematic research. The study considers two types of workspaces: the translation and the orientation. The geometrical approach concerning different mechanism constraints is used to construct the translation workspace, and the orientation one is obtained by a combination of geometrical and discrete techniques. The paper also explores the dependence of the workspaces’ shape and volume on the manipulator geometric parameters. The last section of the article studies the manipulator performance based on the inverse of condition number. Examples executed using MATLAB accompany the suggested algorithms.