基于小波变换的船体NURBS曲面光顺方法研究

根据大量的船体型值点,如何有效地建构出光顺的船体曲面是逆向工程中的一个关键问题,而船体曲线曲面光顺又是船舶型线设计的重点和难点.针对船舶型线的设计特点,研究定义了船体曲面的光顺准则;针对船体曲面的复杂性,引入NURBS的k、l次有理基函数Ri,k(u)、Rj,l(υ)作为小波尺度函数,采用小波变换作为曲面光顺方法,利用高亮线检验曲面光顺性;最后通过实例证明了该方法的有效性和合理性.

Study On fairing of ship NURBS surfaces based on wavelets transform

It's crucial in reverse engineering to reconstruct a fair ship surface based on a large number of hull form points,while the fairing of ship hull curves and surfaces is more important and difficult in hull form design.This paper defines the fairing criteria of ship surfaces according to the features of ship form design.k-order and l-order rational basic functions of NURBS are introduced as the scaling functions of wavelets.The wavelets transform is used as surface fairing approach.Finally,high-light lines are applied to verify the fairing degree.The practical example proves that the approach is effective and reasonable.