A Simple Asymmetric Hysteresis Model for Displacement-Force Control of Piezoelectric Actuators

This article presents a simple hysteresis model for piezoelectric actuators that can be used for simultaneous displacement-force control applications. The presented model maps the hysteresis voltage of an actuator to the charge passing through it. It can model asymmetric hysteresis loops and does not require to be inverted for real-time implementations. The presented model consists of two exponential functions which are described by only four parameters that are identified from a single identification experiment. Another advantage of the presented model over the existing models is that, it requires measurements of current rather than charge. A simultaneously varying displacement-force experiment is created to frame the model. An average absolute error value of 8 % for the hysteresis voltage-charge fit is calculated. Consequent displacement and force fits have average absolute error value of 2.5 %, which are similar to the best reported in displacement-force control literature.