Multi robot exploration using a modified A* algorithm

Abstract

Exploration of an unknown environment is one of the major applications of multi robot systems. A popular concept for the exploration problem is based on the notion of frontiers: the boundaries of the current map from where target points are allocated to multiple robots. Exploring an environment is then about entering into the unexplored area by moving towards the targets. To do so they must have an optimal path planning algorithm that chooses the shortest route with minimum energy consumption. Aiming at the problem, we discuss a modification to the well known A*algorithm that satisfies these requirements. Furthermore, we discuss improvements to the target allocation strategy, by pruning the frontier cells, because the computation burden for optimal allocation is increases with the number of frontier cells. The proposed approach has been tested with a set of environments with different levels of complexity depending on the density of the obstacles. All exploration paths generated were optimal in terms of smoothness and crossovers. © 2011 Springer Berlin Heidelberg.