Kinematics of a Special 3-DOF 3-UPU Parallel Manipulator

This paper discusses kinematic of a special 3-UPU parallel pyramid manipulator by using two different principal, in every branch two middle revolute pairs are perpendicular to each other. This mechanism has three instantaneous translational degrees of freedom, but it is not a three-dimension translational mechanism like the general 3-UPU mechanism with two middle revolute pairs parallel to each other in every branch. By analyzed in depth this special mechanism, we discovers some interesting and special characteristics of the mechanism. All of the results are useful for enriching the mechanism theory and should be applied in mechanism design.Copyright © 2002 by ASME