Characterization of link failures in multi-agent systems under the agreement protocol

The concept of detectability for a link with respect to an agent in a multi-agent system is introduced in this work. Link failures in the network are characterized in terms of their detectability, depending on how a link failure affects the response of a particular node in the system, and whether the link failure can be determined by observing that node's response. Sufficient conditions for detectability are provided and it is pointed out that link failures are detectable for a class of directed graphs with rooted out-branchings. The conceptually related notion of distinguishable directed information flow graphs is also introduced, and its importance in a multi-agent system is discussed. Simulation studies reveal that the obtained analytical results hold for randomly initialized network configurations.