Design and implementation of a leader-follower cooperative control system for unmanned helicopters

In this paper, we present a full scheme for the cooperative control of multiple unmanned aerial vehicle(UAV) helicopters. We adopt the leader-follower pattern to maintain a fixed geometrical formation while navigating theUAVs following certain trajectories. More specifically, the leader is commanded to fly on some predefined trajectories,and each follower is controlled to maintain its position in formation using the measurement of its inertial position andthe information of the leader position and velocity, obtained through a wireless modem. More specifications are made formultiple UAV formation flight. In order to avoid possible collisions of UAV helicopters in the actual formation flight test,a collision avoidance scheme based on some predefined alert zones and protected zones is employed. Simulations andexperimental results are presented to verify our design.