Real-Time Pathfinding in Multirobot Systems Including Obstacle Avoidance

Abstract

The paper describes an approach to the solution of the find path problem, including obstacle avoidance in multirobot systems. The design of multirobot systems requires an overall approach where not only parts of the structure, including the hierarchy are considered, but a complete concept, including the dynamics of the robots, has to be developed. In this paper the structure of these systems is based on the nonlinear con trol approach. The method for real-time pathfinding itself uses a systematic design procedure for multirobot systems, which includes the hierarchical coordinator. This hierarchical coordinator is designed for real-time collision avoidance, where the collision avoidance strategy is based on an analyti cally described avoidance trajectory that serves for collision detection as well as avoidance. The efficiency of the new approach for real-time pathfinding is demonstrated by several cases of practical interest, such as collision avoidance between three robots, interaction of three stationary robots and a stationary obstacle, as well as interaction of mobile robots and moving obstacles, including obstacles of variable size and different shapes.