Observability of multi-agent network sensing systems

This work addresses the observability properties of lineartime-invariant systems that are monitored by a sensor networkthat provides access only to relative measurements and partial absolute observations of the state-space variables. Graphtheoretical tools are deployed to represent the information sharing links between the sensors of the network. The results areextended to multi-agent coordinated systems that are independently controlled or execute distributed control protocols. Explicit analytical conditions are derived that determine the system's observability with respect to the spectral characteristicsof the information-sharing network. The system's observability is further investigated for multi-agent systems governed bythe agreement dynamics where only a singleton measurementis available. The analysis is disseminated to the design of distributed observers where the agents have only available their relative displacement measurement from their neighbors. The distributed observer's estimation error is rendered globally asymptotically stable by the addition of an anchor node that has accessto the absolute motion of a single agent (node). The theoreticalanalysis is validated through numerical simulations.