Synchronization in a network of identical continuous‐ or discrete‐time agents with unknown nonuniform constant input delay

This paper studies the synchronization problem for multiagent systems with identical continuous‐ or discrete‐time agents with unknown nonuniform constant input delays. The agents are connected via full‐ or partial‐state coupling. The agents are assumed to be asymptotically null controllable, ie, all eigenvalues are in the closed left‐half complex plane for continuous‐time agents or in the closed unit disc for discrete‐time agents. We derive an upper bound for the input delay tolerance, which explicitly depends on the agent dynamics. Moreover, for any unknown delay satisfying this upper bound, a low‐gain–based protocol design methodology is proposed without relying on exact knowledge of the network topology such that synchronization is achieved among agents for any network graph in a given set.