Multi-ship collision risk situation assessment based on finite interval cloud model

The assessment of multi-ship collision risk situation holds important theoretical value and practical significance for enhancing waterborne vessel safety supervision and ensuring safe navigation. However, maritime multi-ship navigation risks are often influenced by the coupled influence of hydro-meteorological conditions and multi-ship navigation situations, exhibiting significant uncertainty and fuzziness. In order to address those gaps, this study aims to propose a collision risk assessment method for multi-ships. First, a dual-dimensional evaluation indicator system integrating hydro-meteorological factors and multi-ship characteristics was constructed, accompanied by six calculation methods for indicator values, providing an operational basis for accurate risk assessment. Subsequently, game theory was employed to integrate weighting results derived from the best-worst method and the extension correlation function method, so as to mitigate the one-sidedness of a single weighting approach. Finally, based on the designed indicator interval grades, a finite interval cloud generator was constructed to characterize the fuzziness and uncertainty of the indicators, thereby achieving a precise quantitative rating of multi-ship collision risk. Validation through four groups of multi-ship potential encounter scenarios in the Bohai Sea of China shows that the proposed method can accurately distinguish the risk levels of different scenarios. Moreover, the variance of the evaluation results is 1 to 4.17 times that of the traditional extension cloud model, indicating higher confidence and sensitivity. The method provides objective and precise technical support for navigation situation monitoring in multi-ship potential encounter scenarios.