A graph search algorithm for indoor pursuit/evasion

Athanasios Kehagias,Geoffrey Hollinger,Sanjiv Singh

doi:10.1016/j.mcm.2009.06.011

Athanasios Kehagias, Geoffrey Hollinger + Show 1 more

Open Access

https://doi.org/10.1016/j.mcm.2009.06.011

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Abstract

Using concepts from both robotics and graph theory, we formulate the problem of indoor pursuit/evasion in terms of searching the nodes of a graph for a mobile evader. We present the IGNS ( Iterative Greedy Node Search) algorithm, which performs offline guaranteed search (i.e. no matter how the evader moves, it will eventually be captured). Furthermore, the algorithm produces an internal search (the searchers move only along the edges of the graph; “teleporting” is not used) and exploits non-monotonicity, extended visibility and finite evader speed to reduce the number of searchers required to clear an environment. We present search experiments for several indoor environments, in all of which the algorithm succeeds in clearing the graph (i.e. capturing the evader).

Highlights

IntroductionIn this paper we present a formulation of pursuit / evasion as a graph search problem and introduce an algorithm to solve this problem
In this paper we present a formulation of pursuit / evasion as a graph search problem and introduce an algorithm to solve this problem.In broad terms pursuit / evasion (PE) involves a team of K pursuers trying to locate / capture a mobile evader
We have presented an approach to robotic indoor PE which is based on (a) discretization of the indoor environment and conversion to a graph, (b) search of the graph

Summary

Introduction

In this paper we present a formulation of pursuit / evasion as a graph search problem and introduce an algorithm to solve this problem. In broad terms pursuit / evasion (PE) involves a team of K pursuers trying to locate / capture a mobile evader. Several more speci...c variations of the problem can be de...ned, depending on the capabilities of the pursuers and the evader (and the information available to each of them), the environment in which PE takes place, the type of solution sought and so on. 1. The pursuit takes place in an indoor environment (e.g. a house, an o¢ ce building) and the evader cannot leave the environment (i.e. no exits are available). 2. The evader is adversarial (i.e. wants to avoid capture), arbitrarily fast and has complete knowledge of the environment map and the pursuer locations

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