Adaptive predefined-time fuzzy control based on command filtering for uncertain time-delay nonlinear systems

This study explores the issue of tracking control for strictly feedback nonlinear systems affected by internal uncertainties and external disturbances. An adaptive predefined-time fuzzy control scheme based on constructing a novel command filter is proposed, which ensures that the tracking error can converge to a region close to zero within a predefined time and effectively addresses the complexity explosion problem in applying the backstepping method. A fuzzy logic system is used to approximate the unknown nonlinear terms, while an adaptive control method handles external disturbances. In addition, the Pade approximation method is employed to transform the time-delay system model into a delay-free form, which facilitates the controller design. The main benefit of this approach is its ability to ensure that the tracking error converges within a specified time, even in the presence of internal uncertainties and unmatched external disturbances. Finally, simulation results validate the effectiveness of the theoretical findings.