Global output‐feedback adaptive regulation for planar time‐delay nonlinear systems with polynomial growth

Abstract

AbstractThis paper addresses the problem of the global adaptive regulation via output feedback for a class of uncertain planar time‐varying delay nonlinear systems with an unknown control coefficient and unmeasured states dependent growth. The growth rate is the form of an unknown constant multiplying polynomial of output, and the upper bounds of unknown control coefficient and unknown time‐varying delay are both not required to be known. A systematic non‐identifier‐based output‐feedback control scheme is developed by combining the idea of universal control, backstepping technique, and Lyapunov–Krasovskii theorem. The global regulation of nonlinear systems and the global boundedness of the closed‐loop system can be simultaneously achieved by the designed controller based on a dynamic high‐gain observer and a proper update law. A practical example illustrates the efficiency of the proposed method.