Development of 3 Degree-of-Freedom Spherical Actuator with Auxiliary Poles and Reduced Current Phases

Abstract

　Multi-Degree-of-Freedom (Multi-DOF) actuating systems are composed of several single-DOF motors, which results in large, heavy and complicated structures. In order to solve these problems, various multi-DOF spherical actu-ators have been actively studied. However, the spherical actuator requires many current phases. In this paper, in order to reduce the current phases, a spherical actuator with auxiliary poles is proposed. The proposed actuator can rotate in 3-DOF with 5 current phases. Finally, the torque characteristics of the proposed actuator are evaluated through 3-D FEM analyses.