Modeling of Piezo-Actuated Positioning Systems

Piezoelectric actuators (PEA) are commercially available for producing extremely small displacements. If a PEA is used to drive a positioning mechanism in a given application, the combined dynamics is then different from the one where only a PEA is considered. In the literature, this dynamics was approximated empirically as that of a second-order system. However, there is a lack of the rationale for such an approximation, thus leaving some issues to be addressed such as the scope of and the error involved in the approximation, etc. This paper is to provide such a rationale as well as the experimental verification.