Event triggering based adaptive tracking of uncertain nonlinear systems with unknown control coefficients

In the framework of event-triggered control, the question of practical tracking of a sort of nonlinear systems with serious uncertainty is addressed in this work by virtue of adaptive output feedback control scheme. Especially, system nonlinearities not only depend on the unmeasurable states, but also allows the existence of output polynomial function. By combining extended Lyapunov matrix inequalities, non-identification adaptive technology and dynamic scaling transformation technology, this article proposes an adaptive output feedback control scheme within the event triggering control framework to realize global practical tracking control of closed-loop system. Simultaneously, it must be mentioned that the proposed control method includes dual gain: static gain and dynamic gain, where the latter can effectively compensate for severe uncertainty, output polynomial functions, time-varying control coefficients, and errors caused by event triggering mechanism; in addition, so as to reduce the transmission frequency of control signals, the event triggering mechanism on account of fixed threshold strategy is adopted. By means of Barbălat’s lemma and Lyapunov’s stability theorem, one can prove that the designed control strategy insures that the closed-loop system states are bounded under any initial conditions, while the tracking error is driven to a prescribed interval after a limited time. Also, the Zeno behavior is successfully ruled out. Eventually, one illustrative example is put forward to verify the correctness of the presented approach.