Event-triggering strategy is one of the real-time control implementation techniques which aims at achieving minimum resource utilisation while ensuring the satisfactory performance of the closed-loop system. In this paper, we address the problem of robust stabilisation for a class of nonlinear systems subject to external disturbances using sliding mode control (SMC) by event-triggering scheme. An event-triggering scheme is developed for SMC to ensure the sliding trajectory remains confined in the vicinity of sliding manifold. The event-triggered SMC brings the sliding mode in the system and thus the steady-state trajectories of the system also remain bounded within a predesigned region in the presence of disturbances. The design of event parameters is also given considering the practical constraints on control execution. We show that the next triggering instant is larger than its immediate past triggering instant by a given positive constant. The analysis is also presented with taking delay into account in the control updates. An upper bound for delay is calculated to ensure stability of the system. It is shown that with delay steady-state bound of the system is increased than that of the case without delay. However, the system trajectories remain bounded in the case of delay, so stability is ensured. The performance of this event-triggered SMC is demonstrated through a numerical simulation.

Event-triggered controllers are well known for guaranteeing the desired stability for a sampled-data system with minimum resource utilization. Over the past decade, the study has revealed that the overall performance improvement for a sampled-data system can be achieved by replacing the time-based sampling with an event-triggered one. The design of sliding mode control (SMC) in the event-triggering framework has also shown similar outcomes, especially for uncertain systems. There are different design strategies for event-triggered SMC available in the literature for networked dynamical systems that are potentially affected by uncertainties and transmission delays. The purpose of this survey article is to present the state of the art on event-triggered SMC and familiarize the readers with the design techniques with their pros and cons, since this will be very helpful to the researchers and engineers for implementing SMC using event-based feedback strategies.

In this study, the authors present a robust trajectory tracking control for a class of uncertain Euler–Lagrange (EL) systems using event‐triggered‐based sliding mode strategy. Here, the sliding mode‐based tracking control is designed to ensure the robust stability of EL systems in the presence of external disturbances/uncertainties. Unlike periodic implementation, in event‐triggering strategy, the control signal is updated on demand subject to system stability, so the frequent periodic execution of control tasks is avoided. Here, the event‐triggered implementation of the sliding mode‐based tracking control achieves the robust stability with desired steady‐state performance and reduced computations of control. To realise this, sufficient conditions are derived using Lyapunov analysis such that the proposed controller yields desired tracking performance. It is shown that the triggering condition proposed here ensures Zeno free execution of triggering sequence. Finally, the theoretical development of the study is illustrated through numerical simulation on a two‐link robotic manipulator.