Event-Triggered Control for Strict-Feedback Nonlinear Systems With External Disturbances

In this paper, the event-trigger adaptive control problem is investigated for a class of nonlinear systems with unknown external disturbance. An estimator is designed to estimate the unknown upper bound of the disturbance-like term, which presents the uncertainties caused by external disturbance, a measurement error of input, and an unknown gain parameter. Unlike the existing results, the bound of tracking error is not only independent of the size of unknown system parameters but also can converge to zero. Moreover, new proof of Zeno-free under the discontinuous input is presented. It is shown that the designed adaptive controller ensures the stability of the closed-loop system and achieves desired tracking performance.