Analysis of trans-domain motion process of bullet-shaped trans-domain amphibious vehicle

A fully functional prototype of a bullet-shaped trans-domain amphibious vehicle with the ability to perform reciprocating cross-medium movements has been developed. Once the bullet-shaped underwater vehicle completes its designated underwater tasks, upon reaching a suitable location for surface observation, it will transform into a bullet-shaped coaxial counter-propeller aircraft to carry out cross-domain out-of-water and performing aerial flight missions. The successful transition of the vehicle into amphibious mode is attributed to the design of an innovative energy attitude multiplexing mechanism. Simultaneously, a rational and effective hybrid-switching strategy has been proposed to enhance the reliability of the vehicle's amphibious mode transition. In view of the complex and changeable cross-domain environment, we have adopted a modular design concept, breaking down the entire cross-domain movement process into three key phases: air operation flight, transient cross-domain, and underwater active sailing. Detailed theoretical analysis, algorithm design, and experimental research have been conducted for each phase. This paper proposes and expounds the key design principles, evaluates the performance indicators of key components, and weighs the matching of body dynamics and propulsion performance to ensure that the vehicle achieves the expected performance. Finally, the success of the test at different phases further proves that the vehicle has the ability to achieve complete cross-domain operation.