A robust control framework for smart actuators

Hysteresis in smart actuators presents a challenge in control of these actuators. A fundamental idea to cope with hysteresis is inverse compensation. But due to the open loop nature of inverse compensation, its performance is susceptible to model uncertainties and to errors introduced by inverse schemes. In this paper, we develop a robust control framework for smart actuators by combining inverse control with the l/sub 1/ robust control theory, where the inversion error is modeled as an exogenous disturbance with a magnitude bound quantifiable in terms of parameter uncertainties and inversion schemes. Through the example of controlling a magnetostrictive actuator, we present a systematic controller design method which guarantees robust stability and robust trajectory tracking while taking actuator saturation into account. Simulation and experimental results are provided.