Externally excited coordination of autonomous formations

Inspired by the recent "Robot Sheepdog Project" in the literature, in this paper a new method for coordination of multi-agent systems moving in a 2-dimensional region with the obstacles along a collision free trajectory is presented. A two level decentralized control scheme is proposed. At lower level, for the agents within the formation, "the sheep", the only concern is to keep that of their formation shape intact and avoid inter-agent collision. At the higher level, an intelligent agent, "the sheepdog", is responsible for determining a collision free trajectory for both the formation and itself, and then coordinating the formation motion along this computed path sequence. This sheepdog utilizes a repulsive vector (acting as a source of repulsive force) to drive the formation along the planned path. The effectiveness of the proposed scheme is demonstrated via simulation results in the presence of multiple obstacles.