Ellipse-based modelling of hysteresis in a smart actuator

This work investigates the elliptical modelling of hysteresis in a smart actuator. The actuator in question is a rolled dielectric elastomer (DE) tubular actuator. The actuator actually demonstrates asymmetric hysteresis behaviour due to an inherent nonlinear voltage-strain characteristic. In this contribution the dynamic asymmetric hysteretic characteristics of the voltage driven tubular actuator are initially decomposed into the nonlinear static voltage-strain characteristic in series with a symmetric hysteretic characteristic. A gain scheduling term is introduced to compensate for the nonlinear voltage-strain behaviour of the actuator thereby producing the symmetric hysteretic characteristic of the actuator. The symmetric hysteresis characteristic seems to be elliptical in nature. In this contribution the modelling of this `decomposed´ symmetric hysteresis characteristic is investigated using an ellipse-based modeling approach.