H4: a new family of 4-DOF parallel robots

This paper presents a new family of fully-parallel robots providing 3 translations and 1 rotation about a given axis. Such machines are aimed to use in robotics or machining. The ability of the proposed structure to provide the needed DOF is first proved. Position and velocity relationships are given. Finally, constructive designs are presented that show the effectiveness of the solution with either linear or rotational actuators; symmetrical and asymmetrical designs show that the H4 principle can be the base of a complete family of machines.