Motion Control of Three-Degree-of-Freedom Spherical Actuator Driven by Four-Phase

Abstract

　Spherical actuators have many advantages such as high accuracy due to multiple-degree-of-freedom direct-drive and downsizing by reduction of the number of actuators. However, the conventional spherical actuators have complicated structures and control units. In order to solve these problems, we proposed a three-degree-of-freedom (3DOF) actuator driven by four-phase. The actuator can generate 3DOF motion by a four-phase inverter and four-coil. This paper describes a dynamic modeling and motion control method for the proposed 3DOF actuator. The simulation results showed that the actuator can be controlled in 3DOF by the proposed control method.