Design and Analysis of a Reconfigurable Joint

A new type of reconfigurable joint named rU is developed to extend the application range of the parallel workbench which is useful to expand the reconfigurable characteristics of the parallel mechanism. It could switch between three different topological configurations by changing two reversing pins of this joint. These three configurations are different in degree of freedom and topology. The rU joint has better reconfigurable characteristics by comparing with the popular reconfigurable joints. It is also testified by constructing a reconfigurable limb (rU)P(rU) and analyzing the constraint screws of the limb (rU)P(rU) when it switches between various configurations in different degrees of freedom based on the screw theory. All of their constraint screw systems are carried out. It is proved that the reconfigurable limb with the reconfigurable joint has multiple degrees of freedom configurations.