Global adaptive regulation for time-delay nonlinear systems with saturated input

In this paper, the global adaptive stabilization problem for a class of uncertain time-delay nonlinear systems with unmeasured state dependent growth and saturated input is addressed by output-feedback. The nonlinearities depend on both the unmeasured states and the unknown polynomial-of-output growth. To handle the unmeasured state and the saturated input, a distinct observer and an auxiliary system with only one high-gain updated in a new form, are introduced, respectively. Moreover, a systematic output-feedback control scheme is proposed by using the method of backstepping. The designed controller can guarantee that all the states of the closed-loop system are global bounded. Finally, a practical example shows the validity of the proposed method.