High-Level Local Control Strategies for the Coordination of Large Groups of Mobile Autonomous Agents

Yale University, New Haven CT

Investigators

Abstract

Intellectual Merit: Remarkable advances have been made in recent years in the development of small, agile, relatively inexpensive mobile autonomous vehicles, ultimately intended for a wide variety of purposes such as search and rescue, exploration, environmental monitoring, distributed sensing, the cleaning and maintaining of structures, etc. The existence of such vehicles and the anticipated development of still more advanced versions raises compelling questions: Can large numbers of small autonomous vehicles be successfully deployed in the form of a "swarm" or "flock"as a search team, an exploration group, or something similar, to cooperatively carry out a pre-scribed task and to respond as a group to high-level management commands? Can such a group reliably function robustly, in a difficult or even uninhabitable environment such as outer space or under sea, possibly without a designated leader, with limited communications between its mem-bers, and/or with the "roles"of its members not all the same and perhaps changing with time? What can we learn about how to organize these groupings from biological groupings such as insect swarms, bird ocks, and fish schools? Is there a hierarchy of "compatible" models appropriate to swarming/schooling/ ocking which is rich enough to explain these behaviors at various "resolutions" ranging from aggregate characterizations of emergent behavior, to "point models" for each vehicle, to even more detailed descriptions which model individual vehicle dynamics? In broad terms, these are the issues we propose to address More specifically, we propose to study distributed multi-vehicle motion control algorithms with the aim of better understanding the concepts upon which large classes of such algorithms might depend. For example, we would like to better understand the implications of changing nearest neighbor sets and how this intrinsic property can be modelled and analyzed within the context of switched dynamical systems. We would also like to understand how to analyze asynchronous systems, which because of coarse modelling, exhibit non-deterministic state transitions. We also propose to explore, devise and evaluate alternative data structures/models at various degrees of granularity for representing large homogeneous/hetrogeneous groups of mobile autonomous agents moving in a densely populated environment. These representations are needed for a variety of purposes: for overall management of a large group, for simulating the effects of various protocols on group behavior, etc. Example data structures could include "rigid point formations" and "Euclidean Distance Matrices" as well as other graph-theoretic concepts and vehicle models and various levels of abstraction. Broader Impacts: This project will advance discovery and understanding while promoting teaching, training and learning in at least two different ways. First, graduate students involved in the project will be expected to attend and present there results at technical meetings. Second, project graduate students will contribute to and participate in a short course on the topic which we envision organizing and giving towards the end of the project. We cannot think of any especially unusual way in which this project might broaden participation of underrepresented groups, although we certainly would encourage such participation. This project will enhance infrastructure for research and education in at least two ways. First we expect to continue our crossdisciplinary collaboration with our environmental biologist colleagues with whom we've already been working for several years. Second, we expect to continue to collaborate with our experimentalist colleagues who have built an underwater multi-vehicle testbed { originally conceived by this PI } for trying out various control algorithms. We hope to continue to contribute to broadening dissemination to enhance scientific and technological understanding by organizing and running boni fide interdisciplinary technical gatherings like the forthcoming Block Island Workshop on Cooperative Control which we've co-organized and which will take place in June, 2003.