Adaptive control for output-constrained nonlinear systems with hysteresis and uncertainty

An adaptive tracking control is proposed for a class of constrained nonlinear systems with hysteresis and uncertainty. Hysteresis and uncertainty may limit system performance such as giving rise to undesirable accuracy or oscillations, even leading to instability. First, Bouc-Wen model is used to describe the hysteresis, and the upper bound is derived. Then, a Barrier Lyapunov Function (BLF) is adopted to ensure the boundness and achieve the output-constrained conditions. Finally, the adaptive technique is used to approximate the uncertainty of the system and the backstepping controller is proposed to eliminate oscillation and overshoot caused by hysteresis. Furthermore, this controller eliminates the influence of the hysteresis, constraint and uncertain constants simultaneously. The simulation results are presented to illustrate the effectiveness of the proposed method.