Distributed Pursuit of an Evader With Collision and Obstacle Avoidance

The distributed, real-time algorithms for multiple pursuers cooperating to capture an evader are developed in an obstacle-free and an obstacle-cluttered environment, respectively. The developed algorithm is based on the idea of planning the control action within its safe, collision-free region for each robot. We initially present a greedy capturing strategy for an obstacle-free environment based on the Buffered Voronoi Cell (BVC). For an environment with obstacles, the obstacle-aware BVC (OABVC) is defined as the safe region, which considers the physical radius of each robot, and dynamically weights the Voronoi boundary between robot and obstacle to make it tangent to the obstacle. Each robot continually computes its safe cells and plans its control actions in a recursion fashion. In both cases, the pursuers successfully capture the evader with only relative positions of neighboring robots. A rigorous proof is provided to ensure the collision and obstacle avoidance during the pursuit-evasion games. Simulation results are presented to demonstrate the efficiency of the developed algorithms.