Event-Triggered based Sliding Mode Control of Uncertain Linear Systems

This paper presents the implementation of the event-triggered technique on sliding mode control (SMC) method in the case of linear systems with bounded uncertainty. Event-triggered technique is a scheduling strategy to reduce the number of control updates in a feedback loop. The Main contribution of this paper is to implement event-triggered SMC on the linear multi-input linear systems with parameter uncertainties. Although the chattering is inevitable in SMC, to tackle this phenomenon, hysteresis bounds are offered to reduce the frequency of control updates; nevertheless it induces a limit cycle. By updating control law at hysteresis boundaries, as the event-triggering rule, system finally ends to limit cycle. Another contribution of this paper is to reduce the amplitude of this limit cycle according to the variable control input, while guaranteeing no request for successive control updates too. In this paper by properly designing dynamic control law and hysteresis bands based on state trajectory, as the system moves towards the stable point, its amplitude decreases and the limit cycle amplitude fades accordingly. This method is illustrated by an example of linear system with uncertainty in the system matrix. Simulation results depict the applicability of SMC combination with the event-triggered technique.