Decentralized cooperative manipulation with a swarm of mobile robots: The approach problem

In this paper we consider cooperative manipulation problems where a large group (swarm) of non-articulated mobile robots is trying to cooperatively control the velocity of some larger rigid body by exerting forces around its perimeter. We divide the problem into two phases: (1) approach; and (2) manipulation. This paper presents a novel decentralized solution to the approach phase. An artificial potential field is used to control the motion of the robots such that they establish contact with the object while avoiding collisions with other robots. The resulting grasp locally optimizes the group´s ability to resist disturbances. The approach is provably convergent and does not require centralized coordination of the robots. The results are illustrated in simulation.