Event-triggered based global adaptive output-feedback stabilization for nonlinear systems with multiple uncertainties

This paper investigates the global stabilization of uncertain nonlinear systems via adaptive event-triggered output feedback. The system nonlinearities possess unmeasured states dependent growth and the large uncertainties include two components, i.e., the unknown growth rate and the unknown measurement sensitivity. Different from the existing continuous time control counterpart by a recursive way, a brief event-triggered control is redesigned in a universal form. In addition, a high-gain observer is constructed to rebuild the unmeasured states and a new updating law of dynamic gain is provided to compensate the large uncertainties. To exclude Zeno behavior, a time-varying threshold, which is strict positive and decays to zero, is introduced into the event-triggering mechanism. It is proved that the designed adaptive event-triggered control drives the system states globally bounded and convergent to zero. A simulation example is given to illustrate the effectiveness of the proposed approach.