Comparison of real-time control strategies with hysteresis compensation for magnetostrictive actuators

Magnetostrictive actuators are employed for several purposes but, often, the control strategy is strongly affected by their hysteretic behavior. Such issue becomes crucial if dynamic mechanical stress conditions apply. Indeed, the stress must be considered as an additional input. Nevertheless, a compensation scheme with two-input variables can be defined and fruitfully utilized in a suitable invertibility region. In this paper, different control strategies, based on a compensation algorithm able to take into account the applied mechanical stress, are proposed and compared with simpler linear controllers in a real-time setup. Experimental data measured over a magnetostrictive actuator are presented and commented.