Argos: A novel 3-DoF parallel wrist mechanism

This article presents a novel parallel spherical mechanism cabled Argos wit h three rotational degrees of freedom. Design aspects of the first prototyp e built of the Argos mechanism are discussed. The direct kinematic problem is solved, leading always to four nonsingular configurations of the end eff ector for a given set of joint angles. The inverse-kinematic problem yields two possible configurations for each of the three pantographs for a given orientation of the end effector Potential applications of the Argos mechani sm are robot wrists, orientable machine tool beds, joy sticks, surgical man ipulators, and orientable units for optical components. Another pantograph based new structure named PantoScope having two rotational DoF is also brie fly introduced.