Adaptive Event-Triggered Distributed Observer for Unknown-Input LTI Systems

This paper investigates adaptive event-triggered distributed state estimation problems for jointly detectable linear time-invariant (LTI) systems with unknown inputs over directed communication networks. In order to reduce the communication burden, by designing a novel event-triggered mechanism with composite triggering conditions, an adaptive event-triggered distributed observer is proposed for unknown-input LTI systems. Then, it is theoretically proved that the proposed observer can effectively solve the distributed state estimation problems without Zeno behavior exhibiting. Particularly, the proposed distributed observer only requires discrete-time communications among agents for either updating the observer's states or monitoring triggering conditions. Moreover, all parameters of the proposed observer are updated by adaptive laws without requiring any global information, thus achieving plug-and-play operation. Finally, a simulation example is given to show the effectiveness of the proposed distributed observer.