Simulation of a Small Unconventional UUV Performing Low-Speed Maneuvers in Shallow Water with Regular Waves and Current

The low-speed maneuvering dynamics of a small, unconventional, and highly maneuverable prototype UUV are simulated for several high-level behaviors in an energetic shallow water environment. The prototype has dimensions similar to a standard A-size sonobuoy and has neither fins nor propeller. Propulsion and control of the prototype are achieved via six independently rotating jet nozzles providing control in all six dynamic degrees of freedom. Additionally, a shallow water simulation environment with regular waves and uniform current is constructed to evaluate the performance of the prototype in an energetic littoral setting. The 6DOF rigid-body dynamic equations of motion for the prototype are presented and integrated using an explicit two-stage method. As part of the effort, a linearized coefficient-based hydrodynamic maneuvering model, a wave force model, and a current model are developed based on a mixture of classical marine hydrodynamics and CFD-based methodologies. Both propulsion and control of the prototype vehicle are achieved via a PID-based controller linked to a Moore-Penrose pseudo-inverse actuator mapping. Several simulations are presented that validate the accuracy and efficacy of the wave and current models and the pseudo-inverse control strategy. Finally, the prototype UUV is exercised in the simulation environment to evaluate its performance for several low-speed maneuvers and higher-level behaviors.