Author: Xiaotian Xu
Date: Tuesday, March 28th, 2023, at 1:00 pm
Location: EGR-1131B
Zoom (for the Public Presentation):https://umd.zoom.us/j/7739971299?pwd=L3Z4T1dNTlVUT2kxU241ekwxS2RpZz09
Advisory Committee:
Professor Yancy Diaz-Mercado, Chair/Advisor
Professor Nikhil Chopra
Professor Hosam K. Fathy
Professor Jin-Oh Hahn
Professor Erick Rodriguez-Seda, Special Member
Professor Derek A. Paley, Dean’s Representative
Title of Dissertation: Multi-Agent Spatial Coordination Via Time-Variations In Coverage Control
Abstract:
Coverage control of multi-agent systems (MASs) spatially spreads out a group of agents to form a configuration over a domain of interest. This research investigates the two fundamental elements embedded in coverage control, i.e., the time-varying density function and the time-varying domain, and how these can be leveraged to achieve collaborative controls of MASs. We focus on three problems: first, we abstract a robotic swarm, so it can be controlled as a whole where the robotic team adaptively finds the suitable spatial configuration; second, such abstraction of a MAS is extended to a higher-dimensional embedding for an interactive multi-agent aerial cinematography application; and third, a multi-objective formulation is developed to spatially distribute a MAS and take advantage of its collective effort to persistently cover a space.
In contrast to the coverage with time-varying densities which has been actively studied, we address the coverage control over time-varying domains in the first problem, so the control of a MAS, in terms of its position, scale, shape, etc., is enabled and is simplified into manipulating the domain to be covered directly. The agents coordinate themselves to accommodate the evolution of the domain, even when the domain is evolving fast. A MAS control algorithm, named Swarm Herding, which is built upon the proposed control mechanism is implemented. In pursuit of this approach, contributions are made to the problem of coverage control over time-varying convex and non-convex domains for abstracting the swarm and synthesizing the specialized controllers for every agent in the swarm.
In the second, the abstraction is extended to a hemispherical manifold under the geodesic metric, and it is employed to enable an interactive motion coordinator for multi-robot aerial cinematography. The emphases are on collaborative behavior for multiple unmanned aerial vehicles (UAVs), tracking of a dynamic target, and real-time interaction for aesthetic cinematography objectives. Contributions are made in the design of a distributed interactive framework to provide high-level position instructions for a group of UAVs which addresses the gap in the “one-pilot-many-robot” feature.
In the third problem, a multi-objective coverage control of MASs is formulated to take advantage of the collective effort of a team of mobile sensors to persistently explore a domain of interest. In addition to the standard locational coverage objective, a new perceptional coverage objective is introduced to drive agents around in the domain to gain information. The collaboration between agents is defined not only in terms of exchanging the knowledge of the domain as in previous work but also in terms of inter-agent motion coordination which reduces redundant visits to certain locations by agents. Contributions are made with respect to information exchange with performance guarantees, multi-objective coverage control of MASs with time-varying state-dependent density functions, and analysis of the effects of the multiple objectives.