A hybrid aerial underwater vehicle (HAUV) that could operate in the air and underwater might provide tremendous potential for ocean monitoring and search and rescue as well as underwater exploration. Differences between the aerial and underwater environments, along with common disturbances in wind or oceanic currents, present key challenges when designing a robust global controller. This paper presents a nonlinear dynamic controller, otherwise known as the adaptive dynamic surface control (ADSC) scheme, which effectively deals with the challenges aroused by the nonlinearities, uncertainties, and time-varying parameters of the system. First, the mathematical model of the HAUV is developed by means of the Newton–Euler formalism, highlighting the influence of the environment change on the vehicle dynamics. Second, the variations of added mass and damping during the water/air transition are estimated. Finally, the ADSC scheme is used to control and provided robust transition between distinct mediums for the vehicle in simulations, compared with the gain-scheduled proportional–integral–derivative scheme. The simulation results validate the good tracking performance and strong robustness of the presented scheme.

The distinct design concepts of the vehicles operating in air and water is one of the tremendous challenges that constrain the development of the hybrid aerial underwater vehicle (HAUV). This incompatibility consequently results in the enlarging volume and weight of the existing prototypes, as well as the unmatched maneuvering characteristics in both domains. This letter presented a novel miniaturized and lightweight HAUV, “Nezha-mini,” which weighs 953 g and is only A4-scaled. Besides, the low cost and high modularity allow the convenient repair and remanufacturing. Nezha-mini reconciles the complete multi-domain maneuverability within 50 m aerially and 6 m underwater whilst sufficing for the rapid and stable cross-domain locomotion, which benefits from the selection and unique layout of the propulsion system, as well as our proposed multi-modal control strategy and the cross-domain triggering mechanism. The results of the field experiments are in good agreement with the dynamics simulation, demonstrating the performance of multi-domain locomotion in real environments. The preliminary exploration in this letter provides a referential solution for the miniaturization of the highly maneuverable HAUVs for practical applications and creates a feasible platform for the future clustering and networking of HAUVs.