THESIS DEFENSE: COORDINATED CONTROL FOR NETWORKED MULTI-AGENT SYSTEMS

Zhipu Jin

Abstract: Coordination in networked multi-agent systems attracts significant interest in the realm of engineering. Typical examples include formations of unmanned aerial vehicles, automated highway systems, and sensor networks. One common feature for these systems is that coordinated behaviors are exhibited by interactions among agents where information exchange and manipulation are necessary. I will talk about my recent work on three relevant issues: uniform strategy for multi-agent formation control, fast-converging consensus protocols, and packet-based state estimation over communication networks.

Formation control of multi-agent systems involves a harmony among local controller design, interaction topology analysis, and objective agreement among networked agents. We propose a novel control strategy so that each agent responses to neighbors'behaviors as well as acts towards the global goal. Using the tools from signal flow graphs and algebraic graph theory, we show that this new strategy eases the design of local controllers by relaxing stabilizing conditions. Consensus protocols are used to achieve the agreement among agents. We propose multi-hop relay protocols for fast consensus seeking and investigate convergence behaviors of consensus protocols with communication delays.

Efficient estimating the states of other agents over communication links is also discussed. Since data is normally not re-transmitted in order to satisfy real-time requirements, packet drops and random delays are inevitable. Multiple description source codes are introduced to manipulate the data before transmission so that the performance of Kalman filter is improved both for i.i.d. packet drops and  for bursty packet drops.