Global output feedback stabilization for a class of nonlinear systems subjected to both multiple time-varying delays and zero dynamics

This paper investigates the problem of global output feedback stabilization for a class of time-delay nonlinear systems simultaneously subjected to dynamic uncertainties and an unknown output function. Compared with related celebrated works, the considered systems allow the existence of parameter uncertainties in the output function and nonlinearities, dynamic uncertainties of the unmeasurable state, and continuous external disturbances. A new systematic methodology is established by revamping the double-domination technique with the utilization of a dynamic-gain strategy, an output feedback controller together with a delicate state observer is established successfully, which guarantees the convergence of the states of the closed-loop systems. Finally, a simulation example is given to demonstrate the effectiveness of the theoretical results.