Predefined-time adaptive fuzzy tracking control for a class of uncertain nonlinear systems

Abstract

This article investigates the predefined-time adaptive tracking control for a class of uncertain strict-feedback nonlinear systems. The system under consideration is subject to unknown external disturbances, unknown control gain, and completely unknown nonlinear dynamics. To approximate the unknown nonlinear functions, fuzzy logic systems are employed. Based on the proposed stability criterion, both the controller and the adaptive laws are designed such that the settling time can be specified in advance, and the control singularity problem is effectively avoided. Theoretical analysis confirms that all signals in the closed-loop system remain bounded, and the tracking error converges to a small neighborhood around the origin within the predefined time. Finally, both a numerical example and a practical simulation are presented to demonstrate the effectiveness and feasibility of the proposed approach.