This paper presents a decentralized controller to guide a group of aerial robots to converge to and to move along a simple closed curve specified in a three-dimensional environment. This curve may be considered as a perimeter to be surveilled by the robots. The solution presented in this paper is based on an artificial vector field modulated by a collision avoidance scheme and relies only on local sensing. Proofs of asymptotic stability of the proposed controller are devised for a team of kinematically controlled rotorcrafts. Experimental results with a group of autonomous quadrotors are presented to validate the applicability and performance of the approach.
RSJ Advanced Robotics Best Paper Award in 2014.