Mission-oriented cooperative 3D path planning for modular solar-powered aircraft with energy optimization

Modular Solar-Powered Aircraft (M-SPA) is a kind of High-Altitude Long-Endurance (HALE) aircraft which exploits the mission advantage of swarm UAV and the HALE advantage of large aspect-ratio SPA. M-SPA’s separated mode and combined mode give it the potential to maximize the mission efficiency with limited solar energy. In this paper, firstly, oriented by the mission of maximizing the cruise area, the overall design of the M-SPA is modeled, including the energy model, the aerodynamic model and the flight environment settings. Secondly, by analyzing the energy consumption of the flight modes, we design a multi-phase flight mission strategy. Then, a 24-hour three-dimensional (3D) flight profile of the M-SPA is optimized, including the sub-SPA cooperative path planning in the separation mode. Finally, inspired by the Traveling Salesman Problem (TSP), an improved Ant Colony Algorithm (ACA) is exploited to find the optimal path for each sub-SPA, which is further developed into a dynamic separation and combination scheme for the M-SPA. The simulation results show that the mission performance of the M-SPA outperforms that of the conventional SPA, and explicitly, the mission coverage of the M-SPA is slightly less than a linear increase under comparable simulation conditions.