Flocking for multi-robot systems via the Null-Space-based Behavioral control

In this paper the flocking problem for a multi-robot system, consisting in making the robots of a team grouping together, is addressed. The flocking is achieved resorting to the Null-Space-based Behavioral (NSB) control by defining very simple behaviors for each robot of the team and by properly arranging these behaviors in priority. The NSB algorithm, making the robots using only local information, successfully achieves the flocking with or without a rendez-vous point and in eventual presence of obstacles. Extensive simulations and experiments using differential-drive mobile robots prove the effectiveness of the proposed algorithm.