Brian P. Gerkey, Sebastian Thrun, and Geoff Gordon
We study a formof the pursuit-evasion problem, in which one or more searchers must move through a given environment so as to guarantee detection of any and all evaders, which can move arbitrarily fast. Our goal is to develop techniques for coordinating teams of robots to execute this task in application domains such as clearing a building, for reasons of security or safety. To this end, we introduce a new class of searcher, the phi-searcher, which can be readily instantiated as a physical mobile robot. We present a detailed analysis of the pursuit-evasion problem using φ-searchers. We show that computing the minimum number of phi-searchers required to search a given environment is NP-hard, and present the first complete search algorithm for a single phi-searcher. We show how this algorithm can be extended to handle multiple searchers, and give examples of computed trajectories.