Valentinis, FrancisBattista, ThomasWoolsey, Craig A.2024-11-062024-11-062023-07https://hdl.handle.net/10919/121569This article incorporates free-surface and ambient wave effects into a nonlinear parametric model. Subsequently, its use is demonstrated via simulation of a scale model submarine maneuvering under the control of a nonlinear depth-keeping control system in a seaway. An energy-based model is presented, which represents the underactuated submarine in a free-surface-affected state. This model is then used to synthesize a control law using port-Hamiltonian theory and interconnection and damping assignment passivity-based control. The Lyapunov analysis is used to study the stability of the closed-loop system, and a simulation-based demonstration illustrates the performance of the control law. The results demonstrate that a closed-loop nonlinear controller is able to improve the quality of near-surface depth keeping by automatically compensating for parasitic effects in the hydrodynamics that can compromise depth-keeping performance during maneuvers.pp. 752-777application/pdfenIn CopyrightArticle - Refereedhttps://doi.org/10.1109/JOE.2023.3234811483Woolsey, Craig A. [0000-0003-3483-7135]