基于分解的进化算法和多变量分析技术在船型参数设计中应用

Application of Decomposition-Based Evolutionary Algorithm and Multivariate Analysis in Ship Form Parameter Research

引入优化和决策技术讨论船型参数设计的多目标优化论证,基于分解的进化算法(DBEA)将船型参数设计的多个目标优化问题分解为一定数量的单目标优化子问题,采用进化算法同时求解这些单目标优化子问题.DBEA算法的种群由法向边界相交方法(NBI)构建,子问题的优化通过和邻近个体的进化操作完成.采用熵权和灰色关联方法对DBEA算法得到的船型Pareto解集进行综合评价,给出每个设计方案的定量指标排序.基于多变量分析技术讨论了船舶设计变量的层次聚类属性,给出了设计变量间的类别特性.采用多维标度方法(MDS)给出了这些变量在二维平面里的映射图形,结合聚类树形图可以加深对船舶参数设计模型的认识.对一艘3万t油船进行船型参数设计,算例分析表明,DBEA算法能够快速获得分布均匀的Pareto解,灰色关联方法的决策合理可行.

The study of hull parameters of ship is an important design task for ship designers.This task can be treated as a multi-objective optimization project. A decomposition-based evolutionary algorithm（DBEA）was adopted for approximating the Pareto set of multi objective optimization problem.In this way,the multi objective optimization problem was explicitly decomposed into a series of scalar optimization problems.The evolutionary algorithm was used to find solutions to these single-objective optimization problems simultaneously.The gray relational analysis was employed for comprehensive evaluation of Pareto set.The ranking of each solution were obtained after entropy-weights of attributes were provided.The hierarchical clustering of design variables and attribute variables were also investigated.The dendrogram plots were conducted for these variables.The projections of variables on 2-dimensional space were given by using the multidimensional scaling（MDS）skill.The relations of variables were studied together with dendrogram.An example of main dimensions design of tanker with 30 000 DWT was provided for demonstration of the present hybrid method.