A Redundant Parallel Spherical Mechanism for Robotic Wrist Applications

Parallel kinematic structures constitute promising alternative architectures, when compared to their serial counterparts, for developing positioning and orienting robotic mechanisms. The present author, in a previous work, proposed a qualitative procedure that enables the designer to compare kinematic structures from a group of candidates for robotic wrist applications. Among one of the architectures recommended by the method—the 3 RRR+RUR—is theoretically analyzed here, so its kinematic performance is evaluated. In order to verify the theoretical results, a prototype of the kinematic parallel structure considered is tested and its behavior is observed under operating conditions.