π€ AI Summary
This study addresses the systematic bias in predicting motion responses of semi-submersible platforms under long-period swell conditions and the lack of reliable uncertainty quantification. To this end, a dataβphysics hybrid probabilistic forecasting framework is proposed, which integrates numerical wave spectra, hydrodynamic physical models, and Bayesian statistical inference. An error model accounting for heteroscedasticity and temporal correlation is introduced to effectively correct biases in heave response predictions from the physical model. Under excitation conditions near heave resonance and cancellation frequencies, the proposed method significantly improves both forecast accuracy and the reliability of uncertainty quantification, thereby providing high-confidence decision support for offshore operational safety and efficiency.
π Abstract
A framework for probabilistic forecasting of vessel motion is developed and validated for a semisubmersible operating in long period swell. Bayesian statistical methods are applied to predictions of the heave response from a physics model using numerical wave spectra and measured motion data. Model diagnoses motivate an additional level of complexity required for the error structure in the Bayesian model, specifically to account for heteroskedasticity and time-correlated errors. The hybrid model forecasts were evaluated during periods where the heave resonance and cancellation frequencies were excited. The method is demonstrated to be effective for providing reliable quantification of uncertainty and correcting bias in the raw physics model predictions. This justifies its value for improving the efficiency and safety of offshore operations.