Swift: Transition Characterization and Motion Analysis of a Multimodal Underwater Vehicle

This letter proposes a novel conceptual multimodal underwater vehicle, named "Swift", which is capable of dexterous attitude transition for multiple operation modes. Aside from being competent to adjust pitch and roll angles in the range of -90 degrees to 90 degrees, it can achieve in-situ heading angle maneuvering adjustment with nearly 150 degrees in cramped space, without any assistance of external driving mechanisms such as propeller or rudder. Ingenious configuration, design principles, and maneuvering control sequences of actuators are proposed for innovative attitude transition. Other characteristics, such as the shape and internal drive structures, are identical to classic underwater gliders without further upgrading, which offers great portability and extensibility. The description of the transient behavior during agile attitude transitions, particularly the effective estimation of in-situ heading angle adjustment, is greatly facilitated by transition dynamics with modified hydrodynamic compositions. The consistent results of dynamics simulation and various experiments demonstrate the performance of multi-mode locomotion and promote the transition characterization of the prototype.