Fast Preisach modeling method for shape memory alloy actuators using major hysteresisloops

Abstract

The control accuracy of smart actuators, such as a shape memory alloy (SMA) orpiezoceramic actuator, is limited due to their inherent hysteresis nonlinearities with a localmemory, resulting from the influence of a previous input on subsequent behavior. Inaddition, the existence of minor loops in the major loop because of a local memory alsomakes the mathematical modeling and design of a controller difficult for SMAactuators. Therefore, to enhance the controllability of a smart actuator, the Preisachhysteresis model has emerged as an appropriate behavioral model, yet the modeling isdifficult and the model equation complex. Accordingly, to resolve these difficulties,the current paper proposes a simple method based on applying the proportionalrelationship between the major loop and the FOD curves of an SMA actuator to thePreisach model. As such, using only data for the major hysteresis loop, the proposedmethod enables the FOD curves to be easily approximated and the output lengthrapidly computed. The efficacy of the proposed Preisach modeling method isconfirmed based on comparative experiments with the classical Preisach model.