Empirical Analysis of UAS Performance under External Wind

View Video Presentation: https://doi.org/10.2514/6.2022-0199.vid The use of small electric unmanned aircraft systems (UASs) has grown significantly in recent years, thereby creating a need to assess their performance under varying weather conditions. In the presence of external winds, the UAS performance can severely deteriorate in terms of the deviation from its planned trajectory or an increased consumption of battery power. Therefore, it is essential to model the effects of external winds on UAS performance and guarantee their safe operation. In this work, rigorous flight tests are conducted to empirically evaluate the battery discharge rate patterns, for a commercial UAS platform, under constant external winds as well as lateral wind gusts. Additionally, extensive tests are conducted to model the deviation of the UAS from its planned trajectory under lateral wind gusts. The study is conducted for head, tail and cross wind orientations of the UAS, as well as for different flight modes - takeoff, hover, cruise and landing, when applicable. The final results show that the battery discharge rate follows a quadratic trend with increasing wind speed, however, there is no significant change in the battery discharge rate in the presence of wind gusts. Additionally, the deviation in UAS position under external wind gusts increases linearly with increasing wind speed and decreases with increasing UAS velocity. Empirical results are used to model the battery discharge rate and deviation in UAS position as functions of external wind speed.