Reduction of pitching moment generation of a quadrotor UAV in gust with slant rotors

Small multirotor unmanned aerial vehicles (UAVs) are used for civilian applications because they can take off and land vertically and hover as well. Although UAVs have been designed for outdoor applications, they exhibit poor posture stability in gusts owing to the generation of a pitching moment. To operate the UAVs in areas with wind disturbances, reducing the pitching moment is essential. In this study, we applied slanted rotors to a quadrotor UAV to reduce the pitching moment, and evaluated the UAV’s performance in gusts. First, we conducted wind tunnel experiments on a single rotor to estimate the performance of slant-rotor UAVs. Second, we estimated the thrust and pitching moment of slant-rotor UAVs based on a single rotor experiment. Finally, an experiment with a quadrotor model was conducted to evaluate the effect of slanted rotors. Wind tunnel measurements revealed that an outward slanted rotor reduces the pitching moment in a crosswind. The pitching moment of the quadrotor UAV in gusts was reduced by 26% with a rotor slanted 20° outwards.