Dynamic event-triggered minimal-order observer for linear systems

Event-triggered control is a useful approach in networked control to achieve reduction of data transmission between a plant and a controller. In many practical cases, we can not measure all states of the plant. Then, an observer is often used to estimate the states. On the other hand, the dynamic event triggering mechanism that can make inter-event times larger than those of the conventional event triggering mechanisms has been proposed. In this paper, we consider event-triggered output-feedback control of linear systems. First, we propose an event-triggered minimal-order observer to estimate the unmeasured states from the measured states and control input so that we reduce the computational effort to reconstruct the state. Next, we introduce two dynamic event triggering mechanisms that are extensions of the previous work. One is used at a sensor for the sampling of the output of the plant. The other is at the controller for the update of the control input. We show that the proposed control method ensures the asymptotic stability of the closed-loop system. In addition, we derive triggering conditions under the existence of network delays. Finally, we perform a simulation to show the stability of the closed-loop system and the improvement of the average of the inter-event times by the dynamic event triggering mechanisms.