Spatial path analysis for high-altitude solar-powered airship with maximum net energy

The trajectory is a significant factor in the performance of energy systems, including energy production and consumption for solar-powered airships in cruise, especially in high-altitude wind fields. Therefore, this paper aims to analyze the maximum net energy of high-altitude airships based on different cruise strategies, presenting the constant and variable height operation strategies in target tracking for solar-powered airships. This study proposes the solar radiation model and energy model for high-altitude solar-powered airships to calculate their energy production and consumption. We use the natural wind field data to study the flight condition of an airship in detail and obtain the maximum net energy and optimal ascending velocity for the high-altitude airship in the actual wind field. The results show that the start time in target tracking for airships greatly influences optimal trajectory and strategy. The optimal ascending and descending velocities at the starting time of 6:00 are 1 m/s and will not change by cruise direction. These results are beneficial to improve endurance performance of high-altitude airships in cruise.