Stability analysis and nonlinear control of a miniature shape memory alloy actuator for precise applications

This paper presents a new approach for controlling SMA actuators with hysteresis compensation by using two energy based semi active controllers. SMA actuators exhibit severe hysteresis that is often responsible for position inaccuracy in a regulation or tracking system. In this paper, a SMA actuator model is recalled from [Alasty A, Shameli E. Dynamic modeling of a new varying stress SMA actuator for precise applications. In: Proceedings of 2004 IEEE international conference on mechatronics (ICM'04). Istanbul, Turkey, June 3-5, 2004]. Then, a PID and a novel PID-P3 controllers have been suggested to perform a position control. To investigate the stability of controlled system the dissipativity triplets of both controllers are obtained. At the end, simulation results show that in precision tracking control of the proposed SMA actuator, PID-P3 controllers are more efficient than ordinary PID controllers.