Adaptive Fuzzy Finite-Time Backstepping Control of Nonlinear Systems with Input Constraint and Hysteresis Nonlinearity

This paper investigates the adaptive finite-time tracking control issue for a class of nonlinear systems with input constraint, hysteresis nonlinearity, unmeasured states, and external disturbances. Based on the fuzzy logic systems (FLSs), a fuzzy state observer (FSO) is first designed to estimate the unmeasured states. Then, by using the finite-time stability theory, a novel backstepping control scheme is proposed without constructing the hysteresis inverse. The problem of "explosion of complexity" caused by the derivative of virtual controllers is eliminated by utilizing the low-pass filter. Furthermore, a saturation dynamic filter is employed to address the input constraint. It is proved that the proposed controller guarantees that all the closed signals are semi-global practical finite-time stability (SGPFS), and the tracking error converges to a neighbourhood of the origin. Finally, simulation results are presented to validate the effectiveness of the proposed control scheme.