Task switching for specialized mobile robots working in cooperative formation

Abstract

A formation transition strategy for a fleet of cooperative mobile robots is presented in this paper. Switching to a new formation in order to handle a specific task is controlled by subdividing the plane of movement into different zones with the assumption that each zone involves a specialized task to be performed by a specific agent. As such the robots adapt their formation as they hit a new zone, with the leader robot being assigned as the agent that best responds to the new zone task requirements. The proposed system is modeled using nonholonomic mobile robot dynamics. A kinematic and torque controller for nonholonomic mobile robots is presented to control path following and group formation. Collision avoidance is introduced using repulsive potential forces to prevent the agents from colliding during formation transition and to control interagents separation. To demonstrate the proposed system validity, simulation results are presented which show that the group of robots effectively coordinate themselves within each zone as a desired formation by selecting a new robot to be a leader while ensuring smooth switching to a new formation from zone to zone and without collisions.