Algorithms for the Connectivity Constrained Unmanned Ground Vehicle Surveillance Problem

The Connectivity Constrained UGV Surveillance Problem (CUSP) considered in this paper is the following. Given a set of surveillance UGVs and an area with obstacles that is to be covered, find waypoint-paths such that; 1) the area is completely surveyed, 2) the time for performing the search is minimized and 3) the induced information graph is kept recurrently connected. It has previously been shown that the CUSP is NP-hard. This paper presents four different heuristic algorithms for solving the CUSP, namely, the Token Station Algorithm, the Stacking Algorithm, the Visibility Graph Algorithm and the Connectivity Primitive Algorithm. These algorithms are then compared by means of Monte Carlo simulations. The conclusions drawn are that the Token Station Algorithm provides the best solutions in terms of objective value function, the Stacking Algorithm has the lowest computational complexity, while the Connectivity Primitive Algorithm provides a good trade-off between optimality and computational complexity for larger problem instances.