Paper:

# 3-DOF Outer Rotor Electromagnetic Spherical Actuator

## Yusuke Nishiura^{†}, Katsuhiro Hirata, and Yo Sakaidani

Graduate School of Engineering, Osaka University

2-1 Yamadaoka, Suita, Osaka 565-0871, Japan

^{†}Corresponding author,

Conventionally, many single-degree-of-freedom (single-DOF) actuators have been used to realize devices with multiple-degrees-of-freedom (multi-DOF). However, this makes their structures larger, heavier, and more complicated. In order to remove these drawbacks, the development of spherical actuators with multi-DOF is necessary. In this paper, we propose a new 3-DOF outer rotor electromagnetic spherical actuator with high torque density and wide rotation angles. The dynamic characteristics are computed employing 3-D FEM and its effectiveness is verified by carrying out measurements on a prototype. Then, in order to realize further high torque density, the electromagnetic pole arrangement is optimized using Genetic Algorithm (GA) and the effectiveness of the optimized stator poles arrangement is verified.

*Int. J. Automation Technol.*, Vol.10, No.4, pp. 591-598, 2016.

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