A New Linear Oscillatory Actuator with Variable Characteristics Using Two Sets of Coils.

Nowadays, electromagnetic linear oscillatory actuators are used as vibration control devices because of their high controllability. However, there is a problem that thrust and vibration are small at a wide drive frequency range. In order to improve this problem, we propose a new linear oscillatory actuator that can easily change its own characteristics by using two sets of coils. Through finite element analysis, large vibration was observed at 100 Hz in a series connection, and large vibration and high thrust were observed at 70 Hz and 140 Hz in a parallel connection. From these results, we verified that the actuator had two different characteristics due to switchable connections, and could generate high thrust and large vibration by smaller currents at a wide drive frequency range.

Characteristics verification of an independently controllable electromagnetic spherical motor.

We have been developing electromagnetic spherical actuators capable of three-degree-of-freedom rotation. However, these actuators require complex control to realize simultaneous triaxial drive, because rotation around one axis interferes with rotation around another. In this paper, we propose a new three-degree-of-freedom actuator where 3-axes rotation can be controlled easily. The basic structure and the operating principle of the actuator are described. Then the torque characteristics and the dynamic characteristics are computed by employing 3D-FEM and the effectiveness of this actuator is clarified. Finally, the experimental results using the prototype of the actuator are shown to verify the dynamic performance.