Analysis of 2-Degree of Freedom Outer Rotor Spherical Actuator Employing 3-D Finite Element Method

To drive a conventional motor drive system, the number of degrees of freedom needed has to be equal to the number of actuators employed, and this causes the system to be larger and heavier. To solve these problems, the development of a spherical actuator which can rotate around multi axes is being conducted. In this paper, we propose a new spherical actuator with an outer rotor to produce higher torque density and describe the control method for open loop drive. Static torque and dynamic characteristics of the actuator are clarified by employing 3-D finite element method and are verified from experimental results of a prototype.