Testing and modeling of velocity limits of piezoelectric stacks via step and staircase driving voltages

Abstract Piezoelectric (PZT) stacks are extensively applied due to the advantages such as fast response and high precision. The dynamic characteristics of PZT stacks are of vital importance, and one of the most important aspects, velocity output, especially the velocity limit, can determine the dynamic characteristics limits of various PZT stack actuators. However, there is almost no systematic research on the velocity limit of a single PZT stack, which may vary with various factors. This paper investigates the velocity limits of PZT stacks via step and staircase driving voltages, in order to explore the influencing factors of the velocity limit of a single PZT stack and establish a theoretical model to describe the dynamic characteristics of a PZT stack well. Firstly, a group of experiments were performed and the influencing factors of the velocity limits of PZT stacks were analyzed. The results reveal that the velocity limits of PZT stacks are related to the thickness of the PZT layer, the voltage difference and the direction of motion. Then, the multi-degree-of-freedom spring-mass-damper system was established as a theoretical model to characterize the step responses of the velocity output of a PZT stack, which was verified by the experimental data in time domain. A unified prediction model in a linear function form was established to summarize the influencing factors of the velocity limits of PZT stacks, which can be used to predict the velocity limits of PZT stacks quickly and precisely. The results of this research can promote the theoretical research on the dynamic characteristics of PZT stacks and provide a theoretical basis for the joint modeling of PZT stacks and other mechanisms, which can be expected to further promote the performance prediction and optimization of various PZT stack actuators.