Jacobian and Stiffness Analysis of a Novel Six-DOF Parallel Minimanipulator

Abstract

The Jacobian and stiffness matrices of a novel, six-DOF parallel minimanipulator are derived. The minimanipulator consists of three inextensible limbs, each of which is driven by a five-bar linkage to improve its positional resolution and stiffness. All of the minimanipulator actuators are base-mounted. It is shown that, at the central configuration of the minimanipulator workspace, the stiffness matrix can be diagonalized (decoupled). It is also shown that the minimanipulator can be designed to posses direct or torsional isotropic stiffness properties. Moreover, velocity relationships for the minimanipulator drivers are derived and guidelines for obtaining high stiffness are established.