YingLong-I: A Hybrid Aerial Underwater Vehicle Using Integrated Coaxial Counter-Rotating Propulsion

A compact and lightweight hybrid aerial underwater vehicle(HAUV) named YingLong-I is proposed in this letter. The system primarily consists of an integrated coaxial counter-rotating propulsion module, a rudder-based air-water compatible attitude control module, and an attitude switching module, with a compact size of 292 × 292 × 405 mm and a total weight of 2.5 kg. Compared to seperate air-water propulsion modules, the integrated coaxial counter-rotating propulsion module significantly reduces structural volume and weight. Simultaneously, consistent attitude regulation across both aerial and underwater environments is ensured by the unified rudder-based attitude control module. A payload-to-weight ratio of 0.46 (maximum payload: 1.2 kg) is demonstrated by YingLong-I, surpassing quadrotor HAUVs, where ratios are typically below 0.3. The capabilities of YingLong-I, including cross-domain transition, stable aerial flight, underwater navigation, depth-keeping, and vertical takeoff/landing, were verified through field experiments.