Kinematics of the 3\(\text {S}_\text {n}\)PU Spatial Robot

In this chapter, the under-actuated 3\(\text {S}_\text {n}\) PU parallel robot presented in [1] is derived from the 6-3 fully-parallel robot. A compact formulation for its kinetostatics is presented, an essential result for its design and control. Part of the work presented in this chapter was carried out in collaboration with professor Raffaele di Gregorio, from the University of Ferrara, Italy. Part of this work appeared in [5, 6].