Distributed observers for tracking a moving target by cooperative multiple agents with time delays

This paper is concerned with a leader-follower problem of cooperative multiple agents with a switching interconnection topology and communication delay. Distributed observers are designed for the second-order follower-agents to track a moving target (regarded as an active leader) with unmeasurable velocity and unknown constant input. Dynamic neighbor-based rules, consisting of distributed controllers and observers for the autonomous agents, are developed to keep updating the information of the leader. With the help of an explicitly constructed common Lyapunov function (CLF), it is proved that each agent can track the active leader. Moreover, the tracking error is estimated in a noisy environment and input-to-state stability (ISS) is obtained for the time-delay system.