Research on resonance and antiresonance states of free stator of traveling wave ultrasonic motors

Under the condition of high-power drive, the experimental phenomena of free stator of traveling wave ultrasonic motor takes on strong nonlinear effects. Firstly, its corresponding theories are established to analyze and compare the stator's performances at the resonance and antiresonance states. At the same time, some important parameters, such as resonance/antiresonance frequency, mechanical quality, electro-mechanic coupling, and the relative vibration effect, are selected elaborately to evaluate the vibrational performances of free stator. Then, some experimental schemes based on the laser vibration measurement are designed respectively. Under the different drives conditions, the experimental characterizations of free stator at the resonance and antiresonance states are analyzed systematically. Finally, The investigative results show that the performance at the antiresonance state is much better than that at the resonance state. Some conclusions of this paper can provide novel idea and guidance for the choosing of the operating states and driving modes of traveling wave ultrasonic motor.