Formation control of VTOL-UAVs

This paper considers the formation control problem of a group of Vertical Take-Off and Landing (VTOL) Unmanned Aerial Vehicles (UAV) in SE(3). The vehicles among the team are required to track a reference velocity signal and maintain a desired formation. For each vehicle in the formation, we propose a design methodology based on the separation of the translational and the rotational dynamics, using the desired orientation, in terms of the unit-quaternion, as an intermediate variable to achieve our position tracking objective. Global asymptotic stability result of the closed loop system is established using the Lyapunov method. The communication topology between formation team members is assumed to be fixed and bidirectional. Our control scheme can also be applied to the position control of a single VTOL-UAV and constitute, in its own right, an interesting contribution since global results are seldom achieved in the available literature. Finally, simulation results of a scenario of four VTOL-UAVs in a formation are provided to show the effectiveness of the proposed control scheme.