Active Perception and Localization for Multi-Robot Systems

Overview & Synopsis

In this thesis, we tackle challenges in the localization of multi-robot systems, focusing on cooperative localization in non-infinitesimally rigid formations with sensing constraints. Our contributions introduce a framework in which the possibly conflicting goals of connectivity maintenance, task execution and the information acquisition are "mediated" using a quadratic program and the control barrier functions and control Lyapunov function formalism. Another contribution of this thesis addresses distributed active localization of multiple moving targets by a group of flying robots using camera-based measurements, while accommodating other tasks if system redundancy permits. Also in this case, the problem formulation utilizes a quadratic program and control barrier functions. Building on the control barrier function and quadratic program framework, we identify and address limitations in the existing state of the art, particularly in distributed control barrier functions. Our modifications result in a controller that converges to the centralized optimal solution. Lastly, we present an observer methodology as a novel contribution, allowing cooperative localization of a multi-robot system in a common frame using body-frame relative measurements.