Distributed coordination of multi-agent systems for neutralizing unknown threats based on a mixed coverage-tracking metric

Abstract This paper presents a coordination control method for neutralizing multiple threats by a team of mobile agents in a bounded area. Threat here refers to an unexpected target intruding into the area. Without knowing the number of threats, how they maneuver and when to appear a priori, agents equipped with active sensing and actuating devices are driven to detect, track and intercept those threats as many as possible. In order to increase the probability of detecting new threats, a metric (called the mixed coverage-tracking metric) with dynamic task assignment mechanism is introduced. More specifically, the metric is a weighted sum of the travel cost for area coverage and threat tracking respectively. The control objective is to find optimal trajectories and task assignment values of agents that can minimize the expected mixed metric. Based on Voronoi partition of the mission area, a gradient based control law is designed to drive each agent towards its locally optimum configuration. Meanwhile, a task assignment control law is employed to smoothly switch between area coverage and threat tracking depending on the density of detected threats within each agent’s Voronoi cell. Resorting to optimal control and Lyapunov stability theory, the proposed control method can guarantee that each agent asymptotically converges to its centroid of Voronoi cell. Simulation examples are provided to illustrate the effectiveness of the theoretical results.