WuKong: Design, Modeling and Control of a Compact Flexible Hybrid Aerial-Aquatic Vehicle

The significant differences in the physical properties of air and water pose a substantial challenge for the development of hybrid aerial-aquatic vehicle (HAAV), which leading to increased prototype size, heavier thrusters, and reduced efficiency or under-actuation in one of the mediums. This letter introduces “WuKong”, a HAAV with a simple structure, compact size, and high maneuverability. WuKong has a maximum width of only 300 mm in one dimension, with 2.48 thrust-to-weight ratio. Its operational range spans 20 m in the air and 3 m underwater, enabling seamless cross-domain maneuvers. These capabilities are attributed to the use of separate thrusters for aerial and aquatic, in conjunction with the proposed cross-domain hybrid control framework, and the incremental nonlinear dynamic inversion (INDI)-based underwater attitude control law. Through simulations and field experiments, WuKong's cross-domain transition capability and the underwater maneuverability performance are demonstrated. Our development provides a practical solution for HAAV applications and offers a platform for subsequent HAAV collaborative tasks.