“…Distributed coordination of teams of autonomous robots has received increasing attention from the control society in the last decade [1,2,3,4], due to the rapid development of computation and communication techniques as well as powerful embedded systems. One typical coordination task is formation keeping, in which a team of mobile agents is required to move collaboratively so that the team manoeuvres as a whole with a prescribed formation shape [5,6,7,8,9,10]. Formation control of mobile agents, finds various applications in engineering fields, such as sensor networks for data collections [11], unmanned aerial vehicles for military missions [12], and satellite formations for deep space exploration [13].…”