This paper presents the design and field test of a foldable wing unmanned aerial–underwater vehicle (UAUV). The vehicle can complete diving and air operations, and still have the ability of multiple trans-medium water egress and ingress under the condition of carrying mission load during a single flight. The wings can be folded back for drag reduction in underwater sailing and water egress, and unfolded to provide lift for flight after water egress. This paper presents the major components and system design of the vehicle, including the overall structure of the vehicle, the design of the mechanism for self-locking and quick-folding, the design of the electrical system, the selection of the propulsion system, and analyzes the performance gains from foldable wings and foldable propellers. Then the trans-medium field test was introduced, and the analysis and discussion were conducted for the four typical operating conditions of the vehicle, including water sailing, aerial flight, water egress and water ingress. Furthermore, the endurance performance under the corresponding operating conditions is estimated based on experimental data and the current battery energy carried. The presence of foldable wings and a large pitch angle water egress strategy reduces the thrust-to-weight ratio requirement for the vehicle. The results of the field tests can provide important experience and data support for the subsequent application-oriented UAUVs.

中文翻译：

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折叠翼无人机水下飞行器设计与现场试验

本文介绍了可折叠机翼无人机水下航行器（UAUV）的设计和现场测试。该飞行器可完成潜水和空中作业，且在单次飞行携带任务载荷的情况下仍具备多次跨介质进出水的能力。机翼可以向后折叠以减少水下航行和出水时的阻力，并在出水后展开以提供飞行升力。介绍了该车的主要部件和系统设计，包括车辆的整体结构、自锁和快速折叠机构的设计、电气系统的设计、推进系统的选型、分析可折叠机翼和可折叠螺旋桨的性能增益。然后介绍了跨介质现场试验，并对车辆水上航行、空中飞行、进水和出水四种典型工况进行了分析和讨论。此外，还根据实验数据和当前电池所携带的能量来估算相应工况下的续航表现。可折叠机翼和大桨距角排水策略的存在降低了飞行器的推重比要求。现场测试结果可为无人机后续的应用提供重要的经验和数据支持。