A positioning actuator of magnetic shape memory alloys based on fuzzy sliding mode control

Magnetic shape memory alloys (MSMA) has become a potential candidate in many engineering fields. MSMA has advantage of huge strain, which is much larger than other materials. Besides, it has properties of lightness and high frequency response. All of these characteristics make MSMA as a good choice in micro engineering. However, MSMA has obvious hysteresis phenomenon of nonlinear behavior. The difficulty to use the MSMA as a positioning actuator due to the hysteresis is increased. In this paper, we present the prototype of MSMA actuator. The hysteresis phenomenon of MSMA is also discussed. We also demonstrated experiments of positioning control. Fuzzy sliding mode control (FSMC) is a method to control the system without mathematical model, and it can provide the robustness property. Controller design and experiments are discussed. Experiments show that the precise positioning of controls can be achieved.