Observer-based distributed fault detection and isolation for multi-agent systems with time delays and disturbances

In this article, the problem of distributed fault detection and isolation for single fault is considered for multi-agent systems affected by disturbances and communication delays. A bank of unknown input observers based on local information are constructed for distributed fault detection and isolation, and the sufficient conditions are presented to guarantee that the fault-detection residuals generated by unknown input observers satisfy H_/H-infinity. The logic of distributed fault detection is as follows: a agent can be declared as faulty when it's fault residuals exceed the threshold, and the fault residuals of its adjacent nodes are less than the threshold, declaring the existence of the fault.