Performance analysis of a hovering multirotor UAV in open field wind conditions

Abstract

This paper analyses the performance of a battery powered hexacopter Unmanned Aerial Vehicle (UAV), typically used for wind monitoring applications, in inherently stochastic open field atmospheric conditions. The custom-built UAV is equipped with a specifically developed sensor suite to measure UAV platform and flight parametric data, together with environmental data including wind speed and direction. Experimental data were collected during hovering flights under different ambient conditions with free stream wind speeds of up to 12 m/s. The paper proposes an Intermediate Speed Approximation for UAV power consumption modelling for scenarios where the UAV has a relative airspeed similar to the rotor induced velocity. The study also focuses on the impact of increasing wind speeds and atmospheric air density on the power consumption of the hovering UAV, which in turn affect its flight endurance. The results show that the UAV's power requirements for maintaining stable hovering decrease for higher wind speed magnitudes due to the higher air mass flow rate passing through the UAV rotors. The power demand stabilizes at its minimum value for an incident wind speed of 8.0 m/s before increasing again. The UAV power demand was observed to increase with decreasing atmospheric air density, but the overall effect is marginal.