Tethered Lifting-Wing Multicopter Landing Like Kite

Automatic landing of tethered unmanned aerial vehicles (UAVs) is an important issue. Typically, UAVs rely on location sensors such as global navigation satellite system (GNSS) and external cameras to obtain location data. However, harsh environments such as denial GNSS or strong winds make it difficult for UAVs to approach the landing area, and common solutions cannot be used for automatic landing. A tethered lifting-wing multicopter has a structure and static stability similar to a kite. Inspired by kites, this paper proposes a new landing method for tethered lifting-wing multicopters, which can be used without location or velocity sensors. During the landing phase, the tethered lifting-wing multicopter only needs to keep the rotor thrust to actively straighten the tethered cable and a constant attitude similar to that of a kite to keep position stability and increase damping. Meanwhile, the winch only needs to recover the cable at a constant speed until the tethered lifting-wing multicopter returns to its base. Real flight experiments demonstrate the feasibility and practicability of this method.