A Cooperative Hunting Behavior by Mobile-Robot Troops

This paper presents a novel feedback-control law for coordinating the motion of multiple holonomic mobile robots to capture/enclose a target by making troop formations. This motion coordination is a cooperative behavior for security against invaders in surveillance areas. Each robot in this control law has its own coordinate system and it senses a target/invader, other robots and obstacles, to achieve this cooperative behavior without making any collision. Although there is no centralized controller and each robot has local feedback that is relative-position feedback, all the robots are asymptotically stabilized, and they make formations enclosing a target. Each robot especially has a vector referred to as a “formation vector,” and the formations are controllable by the vectors. As for determining the formation vectors, we use a reactive-control framework in which robots have some reactions heuristically designed according to this cooperative behavior. Therefore, this robotic system is a hybrid system that consists of a feedback-control law and a reactive-control framework. The validity of this hybrid system is supported by computer simulations.