Position control of 3-DOF spherical actuator with cogging torque compensation

Abstract

The development of multi degree-of-freedom actuating systems has been required in robotics and industrial machinery fields. In general, however, the actuating system with several degrees of freedom is composed of some single degree-of-freedom motors, which results in large, heavy and complicated st ructures. Therefore, multi-degree-of-freedom actuators are expected to become a key technology to solve these problems and many types of actuators have been studied. We have been developing a 3-DOF spherical actuator which can rotate around multi axes. In this paper, to improve controllability, a new compensation method which cancels out the cogging torque is proposed and the effectiveness of the control method is verified through 3D-FEM and measurements using a prototype.