Methodology for Controlling Unmanned Aerial Vehicle Landing on a Ground Wheeled Robot Tethered by Cable

ABSTRACT For a robotic heterogeneous complex (RHC) consisting of a ground wheeled robot (GWR) and an unmanned aerial vehicle (UAV) connected by a tether mechanism (TM) and subject to steady wind acting on the UAV, a methodology for selecting control parameters for UAV landing on the GWR is considered. Landing is proposed along the straight line connecting the tether attachment point on the UAV with its base on the GWR. A synthesis of control for the TM and UAV engines was carried out to ensure landing within a predetermined time. A corresponding mathematical model of UAV and TM motion was derived. It is shown that the UAV’s equilibrium positions along the line are stable, ensuring minimal engine energy consumption during landing. A synthesis of piecewise-linear damping coefficients in the control systems for the TM and UAV engines was performed by selecting moments of slope change based on synchronizing the instantaneous tether length and the distance from the UAV to the landing point. Simulation of the full equations of motion confirmed the feasibility of the proposed UAV landing methodology on the GWR and the validity of the assumptions made.