Pseudoextended Bouc–Wen Model and Adaptive Control Design With Applications to Smart Actuators

Smart material-based actuators are known to exhibit the hysteresis behavior, and most of them are rate-dependent, i.e., the level of hysteresis depends closely on the rate of input excitation frequency. This behavior is undesirable and has to be eliminated in order to facilitate high-precision applications. Therefore, there is a need for the comprehensive and robust approach to model and control the hysteresis effects. This paper proposes a new model modification to the phenomenological class of the hysteresis model. In this paper, the special case of the Bouc-Wen model is used as the basis for developing the modified one, and its establishment is realized in the discrete-time domain. Through the identification method called “extended particle swarm optimization,” it is verified that the proposed model is able to capture the dynamic and hysteretic behavior of a class of smart material-based actuators with a relatively good accuracy. Then, a robust adaptive control is synthesized based on the proposed model in order to eliminate the hysteresis effects. It is shown that the formulated adaptive controller guarantees the stability of the closed-loop control system. Experimental results show that the proposed control scheme mitigates the hysteresis effects efficiently.