Solving the Watchman Route Problem with Heuristic Search

This paper solves the Watchman Route Problem (WRP) on a general discrete graph with Heuristic Search. Given graph, line-of-sight (LOS) function, and start vertex, task is to (offline) find (shortest) path through such that all vertices in will be visually seen by at least one vertex path. WRP reminiscent but different from covering mapping problems, which are done online an unknown graph. We formalize as heuristic search problem solve it optimally A*-based algorithm. develop series of admissible heuristics increasing difficulty accuracy. Our abstract underlying into disjoint (GDLS) based clusters within same cluster have LOS specific vertex. use solutions for Minimum Spanning Tree (MST) Traveling Salesman (TSP) GDLS WRP. theoretically empirically investigate these heuristics. Then, we show how optimal methods can modified (by intelligently pruning away large sub-trees) obtain various suboptimal solvers without bound guarantees. These much faster expand fewer nodes than solver only minor reduction quality solution.