A Novel Micro Hollow Ultrasonic Motorapplied to Underwater Pan-Tilt-Zoom

In this paper, a micro hollow ultrasonic motor based on radial-torsional vibration mode is designed, fabricated and characterized. This motor is mainly composed of one hollow rotor and one stator bonded by a circular piezoelectric ceramics to excite the stator’s radial-torsional vibration mode. The working principle of the hollow ultrasonic motor is to utilize the radial in-plane mode to convert the revolved motion of the inner ring through the beams. The stator has a diameter of 30 mm and weight of 26.6 gram. The vibration characteristics and output performance of the motor are tested. The no-load speed of the prototype of the motor can be reached 10000 rpm under the driving voltage 300 Vp-p at the driving frequency of 71.44 kHz. The proposed hollow ultrasonic motor provides a new driving method for the fully open structure underwater pan-tilt-zoom (PTZ).