Robust Adaptive Failure Compensation of Hysteretic Actuators for a Class of Uncertain Nonlinear Systems

Hysteresis exists in a wide range of physical actuators. Furthermore, such actuators may be subject to failures or faults which are often uncertain in time, value and pattern during system operation. However, the available results based on adaptive approaches to compensate for unknown failures of hysteretic actuators are very limited. The work of this note is aimed at addressing such a problem by considering controlling a class of strict feedback systems. A scheme designing smooth adaptive control is proposed for this purpose. It is shown that the designed adaptive controller can ensure all signals are bounded and the tracking error asymptotically approaches a pre-defined bound, no matter whether the hysteretic actuators operate in normal or faulty modes.