  This paper solves the rendezvous problem for a network of underactuated rigid
bodies such as quadrotor helicopters. A control strategy is presented that
makes the centres of mass of the vehicles converge to an arbitrarily small
neighborhood of one another. The convergence is global, and each vehicle can
compute its own control input using only an on-board camera and a three-axis
rate gyroscope. No global positioning system is required, nor any information
about the vehicles' attitudes.
