Practical State Estimation With Event-Triggered Sliding Mode Observer

This article deals with the practical state estimation for an uncertain dynamical system under feedback constraints. We propose an event-triggered sliding mode observer to estimate the states in the practical sense, i.e., arbitrary steady-state bound can be achieved for the estimation error irrespective of the disturbance signal. A new sliding mode observer is proposed with the discontinuous output error injection vector of the same order as that of the disturbance vector; therefore the observer can be represented by an interconnection of continuous and discontinuous dynamics. Two scenarios are considered for implementing this observer in the event-triggering framework, viz., the actuator side implementation and the sensor side implementation, in which the observer is run at the actuator and sensor sides, respectively. However, the event-triggering mechanism in both cases is placed in the sensor end to regulate the transmission of output/estimated values. It is shown under the observability assumption that the event-triggered observer estimates the states practically with intermittent communication and disturbance input. Finally, we take a practical example to illustrate the state estimation using the proposed sliding mode observer.