Design, analysis, and implementation of wireless traveling-wave ultrasonic motors

Abstract

Wireless motors have been extensively investigated for their flexibility and convenience, but they inevitably suffer from vulnerability to magnetic field interference, insufficient robustness, and the need for numerous power switches. Therefore, a wireless traveling-wave ultrasonic motor (USM) with high robustness is proposed in this article, which artily integrates capacitive power transfer into a USM to derive the brand-new nonmagnetic wireless direct-drive motor. Prominently, differing from the existing wireless motors, the proposed wireless USM avoids the use of fragile microcontrollers and active or passive switches at the motor side, the control process of which can be completely conducted at the primary side, thus facilitating high-degree integration and maintenance-free operation. In addition, the bidirectional motion capability and flexible speed regulation can be readily achieved by changing the sequence and amplitude of two-phase outputs at the primary side, enabling the real sense of wireless direct drive. Finally, theoretical analysis and hardware experimentation are given to verify the feasibility of the proposed wireless USM for nonmagnetic biomedical and aerospace applications.