An automated monitoring strategy for ultrasonic amplitude prediction of piezoelectric transducer

Piezoelectric transducer (PT) is the key component in power ultrasonics. Its vibration amplitude directly reflects the performance of the transducer. The real time measurement of amplitude is seldomly reported and difficult to be realized due to the high frequency and confined space to accommodate a sensor. Currently, there are no viable solutions for monitoring the amplitude when the tool is engaged in the material. We present a real time, low-cost amplitude monitoring strategy of the PT, incorporating voltage, current and resonant frequency. The piezoelectric and wave transmission equation are combined with the displacement and force boundaries. The displacement amplitude of the PT is predicted by the established numerical model based on the voltage, current and resonant frequency. Validating experiments are conducted and experimental results demonstrate that the amplitude measurements have a good agreement with the mathematic simulation, which has confirmed the validity of the proposed technique.