High-fidelity process plant modeling of an unmanned sailboat with a wing sail based on multi-body dynamics

The dynamics of unmanned sailboats are strongly nonlinear, with the wing sail, rudder, keel, and hull tightly coupled under wind, wave, and current excitation. Control plant models intended for real-time implementation are typically linearised or decoupled, and therefore may not adequately represent flow separation, hull oscillation, or cross-subsystem coupling. High-fidelity process plant models, which are valuable for design validation and digital-twin development, remain comparatively underexplored for unmanned sailboats.

To address this gap, this paper develops a MATLAB/Simulink high-fidelity process plant model for a wing-sailed unmanned sailboat which, to the best of the authors’ knowledge, constitutes a first systematic realisation of this kind. The six-degree-of-freedom multi-body formulation accounts for sail–rudder–keel–hull coupling; hull wave responses are driven by WAMIT frequency-domain potential-flow coefficients; and loads on the foils are described uniformly by the Morison equation, with lift and drag coefficients taken from precomputed CFD maps and distributed through a discretised panel method. The modular implementation supports bidirectional coupling between rigid-body dynamics and environmental forces. Static force characterisation and dynamic response analysis under wave excitation confirm physical consistency, providing a reusable simulation basis for design optimisation, controller validation, and failure-scenario testing under complex sea conditions.