Mission-Oriented Multirotor UAV Design Using Multi-Stage Battery Detachment for Extended Range and Endurance

Multi-stage battery detachment is an effective approach for extending the endurance of multirotor UAVs. However, mission-dependent design guidelines remain insufficient. An optimization framework was developed to estimate the weight margin over an entire mission profile and extend the main mission duration by utilizing the estimated weight margin. The framework was applied to a 7 kg-class quadcopter and evaluated for three scenarios at different forward flight speeds: maximum-range flight, reconnaissance, and maritime search-and-rescue missions. The results showed that the optimal number of detachment stages strongly depended on flight speed. Under hovering conditions and at speeds of 10 m/s or lower, a 13-stage configuration was optimal whereas, at 20 m/s, a 9-stage configuration was optimal because of the higher required power. For the maximum-range scenario, the proposed approach achieved 64.8 km at 10 m/s, representing a 111.8% improvement over the single-battery configuration. In addition, reconnaissance loiter time increased by 183–290%, and the maritime search-and-rescue operational radius increased by 39%. These results provide a practical design methodology for multi-stage battery detachment.