PI and Super Twisting Sliding Mode with Smith Predictor Control Structures for SMA Actuators

This paper aims to design three control solutions for nonlinear processes with Shape Memory Alloy (SMA) wire actuators viewed as controlled processes with dead time. The proposed control solutions are the PI controller with Smith predictor configuration, the sliding mode PI controller with Smith predictor configuration and the super twisting sliding mode PI controller with Smith predictor configuration. The parameters of the proposed controllers are optimally tuned using a Grey Wolf optimizer algorithm. An accurate evolved Takagi-Sugeno-Kang fuzzy model of SMA wire actuators is used to validate the control structures by simulations and their control performance is compared and evaluated.