Robust Control of a Magnetostrictive Actuator

Applications utilizing smart materials are rapidly increasing and include high speed milling and hybrid motor design. Such application utilize magnetostrictive transducers operating in hysteretic and nonlinear regimes. To achieve the high performance capabilities of these transducers, models and control laws must accommodate the nonlinear dynamics in a manner which is robust and facilitates real-time implementation. To this end, the models and control algorithms must utilize known physics to the highest degree possible, be low order, and be sufficiently robust to operate under realistic conditions. In this paper we consider the robust control of a smart structure with disturbances due to inherent hysteresis and sensor noise. We demonstrate the techniques on a magnetostrictive transducers but they are sufficiently general to be utilized on several commonly used smart materials. The performance of the control strategies are illustrated through numerical examples.