Model-Based Investigation of the Influence of Environmental Conditions on the Energy Supply of Multirotor UAVs

Flight time of unmanned aerial vehicles (UAVs) is limited by available energy, which is affected by the mission profile and external factors, such as environmental conditions. Two main environmental conditions that need to be considered are the impact of wind and ambient temperature on the UAV and its energy supply. The purpose of this study is to examine the effects of wind and ambient temperature to conduct a preliminary evaluation of flight performance and flight limitations. For this reason, three locations in the United States—New York City, Miami, and Fairbanks—are selected and the impact of the considered environmental conditions of these areas analyzed. A model is created to simulate wind-dependent flight maneuvers for two flight missions: a delivery flight and a facade inspection mission. These missions are simulated with a temperaturedependent battery model at varying wind conditions to evaluate the effects of the combined environmental conditions. Investigating the extent of the influence and its effect on flight time are crucial steps in developing a digital twin in the future. The results indicate that wind conditions can have either positive or negative effects on the state of charge (SOC) of the UAV battery, depending on the wind speed, direction, and mission type. Furthermore, temperature impacts SOC significantly more than wind does for the missions examined at selected locations. When considering the whole range of environmental conditions, no mission is feasible under the least favorable of the researched conditions (i.e., wind speed of 8 m/s and a temperature below 273.15 K) in New York City and Fairbanks. In the most favorable of the researched conditions (i.e., wind speed of 2 m/s and a temperature of 306.35 K), the SOC reaches its maximum of 59.73% (Miami) at the end of the delivery flight and 74.24% (Miami) at the end of the facade inspection. When simulating average wind speeds and average ambient temperatures, there is also a noticeable difference in power demand for these locations, as the SOC varies between 36.62% (Fairbanks) and 56.77% (Miami) at the end of the delivery mission and between 61.62% (Fairbanks) and 72.55% (Miami) at the end of the facade inspection mission.