遗传算法在船舶自由浮态计算中的应用  

Application of Genetic Algorithm in Ship Free Floatation Calculation

作　　者：陆丛红[1] 林焰[1] 纪卓尚[1] 

机构地区：[1]大连理工大学船舶CAD工程中心,大连116024

出　　处：《上海交通大学学报》2005年第5期701-705,710,共6页Journal of Shanghai Jiaotong University

基　　金：教育部"跨世纪优秀人才培养计划"基金资助项目(1999);辽宁省重大基础研究计划资助项目(2004C060)

摘　　要：根据船舶自由漂浮的平衡条件,将自由浮态计算归结为多目标约束优化问题,并引入遗传算法(GA)对该优化问题进行求解.在船体曲面和甲板的非均匀有理B样条(NURBS)曲面表达基础上,应用GA算法,采用实数编码方式,对船舶自由浮态进行计算,在实践中对GA算法进行必要的改进,提高进化速度,并编程实现.通过对两条实船完整浮态和破舱浮态进行计算,并与传统方法的计算结果对比表明,用GA来解船舶自由浮态的方法是简单可行的.由于该计算是基于曲面表达的计算,故比二维表达基础上的计算更精确.与其他迭代方法相比,它不需要人为给定初始迭代点,只需给出船舶总重量和重心位置;设计变量直接取吃水、横倾角和纵倾角,不必预先计算倾角的正切值,使用方便.According to the equilibrium condition of ship free floating, the calculation of free floatation boils down to a multi-objective constrained optimization problem and genetic algorithm (GA) was applied to the solution of it. Based on the NURBS (Non-uniform Rational B-Spline) surface representation of the hull surface and ship deck, applying GA with real number code, the free floatation was calculated. Necessary improvement of GA was made in practice in order to speed up the evolution, and the corresponding program was implemented. The calculation results and their comparison with the conventional ones of two full-scale ships verify the feasibility of the free floatation calculation with GA and the theory is comprehensible. Because of the surface representation of ship hull and deck, the computation result is more precise than that based on 2D representation. Compared with the other iteration algorithms, it is unnecessary to specify the initial iteration point and nothing is needed other than the total gravity of ship and the center of gravity as the only input. Using the mean draft, heel angle and trim angle as the design variables, it need not calculate tangent values of the angles and is more convenient for application.

关 键 词：船舶自由浮态 遗传算法 实数编码 多目标约束优化 稳性 

分 类 号：U661.21[交通运输工程—船舶及航道工程]