Model and Analysis of Piezoelectric Actuator in Practical Three-Stage Mechanism

Piezoelectric elements (PEMs) are used in a variety of applications. In this paper we developed a full analytical model of a piezoelectric actuator which includes piezostack elements and a three-stage amplification mechanism. The model was derived separately for each unit of the system. Next, the units were combined, while taking into account their coupling. The hysteresis phenomenon, which is significant in piezoelectric materials, was extensively described. A number of hysteresis calculating algorithms were investigated and a new simple method of examining piezoelectric hysteresis was demonstrated. The theoretical model was verified in a laboratory setup. This setup includes a piezoelectric actuator, measuring devices and an acquisition system. The measured results were compared to the theoretical results, while taking into account the nonlinear phenomena of the piezoelectric materials and the three-stage amplification mechanism, and were found to be very similar. Due to its simplicity, this model can easily be modified in order to be applied to other PEMs or other amplification mechanism methods. The main novelty of this work lies in its system-level approach for piezoelectric actuators. All of the system elements include non-linear phenomena, which mutually influence each other. First, each part of the system will be described separately and then, the combined subsystems and the coupling between their parts will be represented. Finally we treat this system as one whole unit.