Efficient Robot Path Planning in the Presence of Dynamically Expanding Obstacles

This paper presents a framework for robot path planning based on the A* search algorithm in the presence of dynamically expanding obstacles. The overall method follows Cellular Automata (CA) based rules, exploiting the discrete nature of CAs for both obstacle and robot state spaces. For the search strategy, the discrete properties of the A* algorithm were utilized, allowing a seamless merging of both CA and A* theories. The proposed algorithm guarantees both a collision free and a cost efficient path to target with optimal computational cost. More particular, it expands the map state space with respect to time using adaptive time intervals in order to predict the necessary future expansion of obstacles for assuring both a safe and a minimum cost path. The proposed method can be considered as being a general framework in the sense that it can be applied to any arbitrary shaped obstacle.