A novel approach in generating 3-DOF motions

Primary objective in the design of spherical actuators or motors is to achieve 3-DOF motions within a compact structure. In the realization of this desired motion, various actuating methodologies have been proposed. In the process of achieving a true 3-DOF motions, spin of the rotor has always been a hurdle for many designers. In this paper, a new and innovative actuating principle coined as the progressive wave method is being proposed and discussed. The novelty lies in the technique to creating the pan, tilt and spin motion. This approach allows pan and tilt motion to be decoupled from the spin motion and thus achieving 3-DOF motions within a single system. A prototype was developed and the proposed working principle was validated.