Two-Degree-of-Freedom Event-Triggered Tracking Sliding Mode Control

This article presents a two-degree-of-freedom sliding mode control with event-triggered feedback to guarantee robust output tracking for an uncertain plant against matched disturbances. The proposed controller comprises an event-based feedback loop for the plant measurements and the analog feedthrough path for the tracking (reference) signal, which is generated by an exogenous system. Here, the event-triggering mechanism uses only the feedback signals, unlike the existing works, and thus, it retains the two-degree-of-freedom architecture in the controller implementation. The main advantage of the proposed event-based controller is that the event mechanism generates a sparse sampling sequence due to the use of only feedback signals. It is seen that the solvability of the tracking problem is reduced to that of the sliding mode regulator equations. Indeed, it is established under this assumption that for any bounded initial conditions, the proposed sliding mode controller guarantees robust output tracking for the closed-loop system with arbitrary accuracy. Finally, the simulation results are presented to demonstrate the output tracking by using the proposed methodology. © 1963-2012 IEEE.