Response improvement of shape memory alloy actuators? with Peltier Elements

Shape memory alloy (SMA) actuators can be deformed by being heated up and cooled down. There are mainly two methods for controlling the deformation of the SMA actuators. The one is to use thermal control devices such as Peltier elements. The other is to electrify the SMA actuators, which utilizes the fact that they are heated up due to Joule heat. The goal of this paper is to improve the response speed of the SMA actuators by using the Peltier elements as well as by electrifying the SMA actuators. First, properties of the SMA actuators and the Peltier elements are examined. Net, an online control method is proposed to find appropriate time intervals for heating and cooling the SMA actuators with the Peltier elements. The proposed method is based on a golden section search which is a simple but efficient optimization method. Then a control method for preheating and precooling the SMA actuators is presented. The experimental results are given to show the effectiveness of the proposed method.