Cooperative path-following control with logic-based communications: theory and practice

This chapter introduces an event-driven, logic-based communication system for decentralized control of a network of nonlinear systems (agents) with the objective of driving their outputs along predefined paths at desired speeds, while holding a desired formation pattern compatible with the paths. An extended cooperative path following (CPF) framework is adopted where communications among agents take place at discrete time instants, instead of continuously. The communication system takes into account explicitly the topology of the communications network, the fact that communications are discrete, and the cost of exchanging information among agents. The theoretical framework adopted allows for the consideration of communication losses and bounded delays. Conditions are derived under which the resulting multi-agent closed-loop system is input-to-state stable, that is stable and with guaranteed levels of performance in the presence of bounded external disturbances and measurement noise. The set-up derived is used to solve the problem of CPF control of multiple underactuated autonomous marine vehicles. The results of experimental field tests with a group of marine vehicles are presented and discussed.