海浪预报不确定下的船舶运动姿态分析方法

A Method for Analyzing Ship Motion Attitude under the Condition of Uncertain Sea Wave Forecast

摘要: 实时准确地估计海浪预报不确定下的船舶运动姿态是一个非常困难的问题。为解决该问题，通过分析海浪预报的随机误差对船舶运动姿态估计的影响，建立基于不确定性海况预报数据的船舶运动姿态估计模型；引入多项式混沌展开方法，实现船舶运动姿态估计的不确定性量化(Uncertainty Quantification, UQ)；利用船舶横摇运动仿真系统对多项式混沌展开(Polynomial Chaos Expansion, PCE)进行验证，并与常用的蒙特卡洛仿真方法(Monte Carlo Simulation, MCS)进行对比。试验结果表明：在船舶横摇运动姿态UQ问题上，PCE方法与MCS估计效果相当，但收敛速度更快，计算速度提升92%，对航行优化和实时评估船舶安全具有重要的意义。

Abstract: The impact of the random error in sea wave prediction on ship motion attitude estimates is analyzed and a model is developed to estimate ship motion attitude under the condition of uncertain sea wave forecast.The uncertainty of the motion attitude estimates is quantitatively decided with PCE (Polynomial Chaos Expansion).The polynomial obtained through polynomial chaos expansion is inspected and verified by means of a ship rolling motion simulation.The commonly used Monte Carlo simulation is also conducted for comparison.The two simulation methods give equivalent results except the new one is 92% quicker.