Distributed bearing-based formation control of unmanned aerial vehicle swarm via global orientation estimation

Most existing formation control approaches for Unmanned Aerial Vehicle (UAV) swarm assume that global position and global coordinate frame are directly available for each agent. To extend the application domain, this paper proposes a distributed bearing-based formation control scheme, without any reliance on global position or global coordinate frame. The interactions among UAVs are described by a directed topology with two-leader structure. To address the issue of unavailable global coordinate frame, we first present a distributed orientation estimation law for each UAV to determine its orientation under the coordinate frame of the first leader. Based on the orientation estimation, we then design a bearing-based formation control law to globally asymptotically track target moving formations. Finally, simulation results are provided to validate the proposed method, which show that the translation, scale and orientation of the formation can be flexibly controlled via two leaders.