Ground Effect Of A Quadcopter Flying Above Inclined Plane

Abstract

Multicopters used for facility inspection are often required to fly very close to structures. However, it is known that the behavior of multicopters in the vicinity of structures can be unstable. In this study, the ground effect when there is an inclined ground plane below the quadcopter was investigated experimentally and numerically. The results show that imbalanced aerodynamic forces which can disturb the flight are generated by different mechanisms depending on the propeller configuration and flight altitude: when flying near the inclined plane with the thrust force of the four rotors maintained constant, the torque acting on the rotors changes depending on the inclination angle of the ground plane. The change in torque is influenced not only by the distance between the rotor and the inclined plane, but also by the distance between neighboring rotors. It was suggested that an imbalance of yawing moments may occur in the quadcopter, which makes flight unstable, depending on the azimuthal angle of the quadcopter with respect to the inclined plane.