Improved Path Planning in Highly Dynamic Environments Based on Time Variant Potential Fields

Introduction Planning collision-free paths is one of the basic skills for a mobile robot performing a goal-oriented task. Especially in highly dynamic environments such as robot soccer there is a need for smooth navigation avoiding the cooperating and competing players. Today, robots in RoboCup [5] are moving at speeds of up to 3 m/s. Navigation thus requires real time path planning considering the movement of the obstacles. Although there are publications on path planning in the robot soccer domain (e.g. [1],[3],[7]), the presented approaches do not incorporate the speed of the obstacles into the planned paths. The majority of the teams in the RoboCup middle size league competition of 2005 are actually completely unaware of the speed of the other robots [6]. To the best knowledge of the authors no team uses information on moving obstacles in their path planning algorithms. This paper presents a new method of path planning for the RoboCup domain that extends the approach introduced by Weigel et al. [7] to time variant potential fields that consider the movement of the obstacles over time. Using this method results in smoother paths and less collisions for several scenarios, that frequently occur in RoboCup. The remainder of the paper explains the method in detail and presents first results.