A Robust Controller for Shape Memory Alloy Actuators

This paper describes a robust mixed-synthesis controller for shape memory alloy (SMA) actuators. The weights for the controller are chosen such that the disturbance rejection criterion is met for low frequencies and robust stability is maintained for high frequencies. Simulation and experimental results show fast and accurate response for strain in the SMA under no perturbation. The performance of the controller is also verified in the presence of load and cooling rate perturbations. The response shows that the controller maintains good disturbance rejection and robust stability. Sinusoidal references are tracked with negligible error in the presence of perturbations. In addition, the controller is also tested for SMA actuators operating in water. The excellent results validate further both the model and the controller used for the SMA actuators