Abstract: To solve the bottleneck problems in the three-dimensional irregular packing problems,two improved methods were proposed.First,the vector graphics were hybridized with bitmaps to describe the 3D irregular parts.The parts were described in form of vector graphics during the primary procedure of packing,and then represented by the cube-shaped particles before seeking optimal packing attitude.To eliminate the gaps between the parts and to export the accurate packing layout,the parts were restored again with vector graphics.Second,the concept of all-attitude in aerospace field was introduced.Multiple surface points were evenly arranged on the sphere through the longitudinal and latitudinal lines.Thus,multiple axis of rotation could be determined by taking the center of sphere as the starting point and the surface point as the ending point.In this way,the part could get more rotating shafts than the traditional method,thus greatly improving the optimization search space of the packing attitude.Numerical examples proved that the proposed algorithm had the advantages of fast execution speed and good layout performance.

Key words: three-dimensional packing, irregular packing, hybrid representation, all-attitude, constructive algorithm

摘要： 针对三维不规则排样构造算法的瓶颈问题提出了两方面改进：首先,将不规则三维零件进行矢量图与像素图的混合表达,在算法的初始阶段,零件采用矢量方式表达;在寻找最优排样姿态阶段则使用立方体微粒表达;在算法末尾阶段为了消除零件之间的缝隙并输出精确的排样图,零件恢复为矢量表达。然后,引入航空航天领域的“全姿态”概念：借助经线和纬线在球体上均匀布置多个表面点;以球心为起点,以表面点为终点,从而确定多个旋转轴。通过这种方法,零件可以获得比传统方法更多的旋转轴,从而大大提升了排样姿态的优化搜索空间。通过算例证明,所提算法具有执行速度快和排样性能好的优点。

关键词: 三维排样, 不规则排样, 混合表达, 全姿态, 构造算法