Non-fragile exponential H_∞ observer-based event-triggered control of uncertain systems with disturbance input:...

This paper is concerned with the problem of exponential H_∞ event-triggered controller design for uncertain systems with disturbance input. The proposed controller is based on a non-fragile observer which is resilient to gain variations. A new event-triggering condition is introduced deciding on the transmission of the current signal. An event-driven state-feedback controller updates the control signals according to the transmitted data. Utilizing the Lyapunov stability theorem, the sufficient conditions for exponential stability of the estimated states and the error system are proposed. It is proven that the state estimates and the error vector converge to a limited region with a pre-specified exponential rate. The stability conditions are given in the form of linear matrix inequalities (LMIs), by solving which, the controller and the observer gains are attained. It is also shown that a positive scalar limits the inter-execution intervals, by analyzing the Zeno behavior. The design procedure has been stated in a step-by-step manner which makes the design very convenient and straightforward. Eventually, the proposed approach is applied to the level control of a four-tank system. The simulation results illustrate the applicability and effectiveness of the method.