Unified minimalistic modeling of piezoelectric stack actuators for engineering applications

Abstract

Piezoelectric (PZ) actuator is widely recognized for its high precision and displacement accuracy even at nanometer ranges. A minimalistic model is proposed in the present work, for PZ stack actuators. In the proposed model, various stack assembly arrangements have been assumed. Separate series and parallel assembly arrangements are suggested for both mechanical and electrical parts of the PZ actuators. The linearized constitutive equations formulated by IEEE, is considered to take into account the electromechanical coupling of the PZ actuator. In the proposed model, stiffness of the connectors in stack assembly have also been taken into account and is modeled as connector spring. To include the effects of connector spring, the relationships of force and voltage with actuator displacement is replaced by the relations between force and voltage with the displacement of point of actuation at the physical system. This leads to a more realistic model of PZ actuator to be used in applications requiring actuator to be modeled as a black-box. With the advent of technology, more and more complex and compact actuating system are emerging into existence. Engineering applications, such as in the field of robotics, that require a black-box modeling of actuators, need simplistic models of the actuators to decrease the computational complexity. The proposed model, being a minimalistic one, qualifies as an ideal candidate for such applications.