Optimal proportional-integral-derivative control of shape memory alloy actuators using genetic algorithm and the Preisach model

Abstract

Shape memory alloy (SMA) actuators, which have the ability to return to a predetermined shape when heated, have many potential applications in aeronautics, surgical tools, robotics, and so on. Although the number of applications is increasing, there has been limited success in precise motion control owing to the hysteresis effect of these smart actuators. The present paper proposes an optimization of the proportional-integral-derivative (PID) control method for SMA actuators by using genetic algorithm and the Preisach hysteresis model. In this work, the numerical Preisach model with geometrical interpretation is used for hysteresis modelling of SMA actuators. This model is then incorporated in a closed-loop PID control strategy. The optimal values of PID parameters are determined by using genetic algorithm to minimize the mean squared error between desired output displacement and simulated output. This is used to reduce hysteresis effects and improve accuracy for the displacement of SMA actuators.