Event-triggered control for a class of switched uncertain nonlinear systems

This paper investigates the event-triggered tracking control for switched nonlinear systems with parametric uncertainties. Due to the interplay between system switching and event-triggered sampling, two problems arise in the control scheme design. One is the mismatch between subsystems and the corresponding controllers as the switch occurs inside the sampling interval. This problem is rather challenging because the existing methods need to know/assume the maximum mismatch period a priori and use some calculation techniques that are only applicable for linear systems. The other is to avoid the Zeno behavior in the event-triggered control since the switch may trigger additional events while such a switch can be sufficiently close to the last triggering instant. To solve the above problems, we co-design a novel switching event-triggered mechanism and a mode-dependent adaptive control law. With this control scheme, the mismatch behavior is addressed without strict assumptions in the literature, and the absence of Zeno is guaranteed by providing a positive minimum inter-trigger time. The tracking error can be regulated to an adjustable neighborhood of the origin. The obtained results are validated by the tracking control of a single-link robotic manipulator. (C) 2019 Elsevier B.V. All rights reserved.