Wake Vortex Attenuation Control of Receiver UAV in Autonomous Aerial Refueling

This paper addresses the difficult wake vortex attenuation control problem for receiver unmanned aerial vehicle (UAV) in autonomous aerial refueling (AAR). When receiver UAV is approaching the tanker aircraft/UAV in AAR, the wake vortex induced by the tanker aircraft/UAV will have adverse effects on the safe flight of the receiver UAV. By introducing the wake vortex into the receiver UAV's equations through wind-effect terms, a receiver UAV model including wake vortex is first given to facilitate the controller design. Then, to investigate the wake vortex attenuation control, disturbance observer technique is incorporated into the dynamic surface control architecture to estimate the lumped uncertainties caused by the wake vortex. By using Lyapunov method, it is shown that the receiver UAV can approach to the tanker aircraft/UAV with high precision in the presence of wake vortex. Finally, simulation results are presented to illustrate the effectiveness of the proposed control strategy.