连续路径下旋转体的扫描实体造型

Swept volume solid modeling of revolutions on curved trajectories

以实体造型仿真和工程应用为目的,基于包络理论和边界描述实体造型法,提出了旋转体在连续路径下进行扫描实体造型的一种新方法.该方法针对扫描实体的造型难点,将整个造型过程分为扫描路径的分析(包括连续路径的离散和离散点位置上局部标架的建立)、扫描轮廓的提取(包括各个离散点位置上扫描母体旋转体速度分量的计算和轮廓曲线的提取)、扫描实体包络面的构造(包括对各条扫描轮廓曲线的分组和糅合)以及扫描实体的完整造型(包括对包络面与入口和出口边界的连接).与现有方法相比,该方法能快速有效地以旋转体为扫描母体进行扫描实体造型,在减少计算量的同时保证了造型的精确性.

A novel algorithm based on envelop theory and B-rep modeling technique was proposed aiming at the difficulties of swept volume solid modeling for manufacturing. The algorithm was divided into four parts： analysis of trajectory curves including trajectory discretization and reference frame establishment,extraction of swept profiles including evaluation of velocity vectors on revolution generators and calculation of swept profiles at each discretized position, generation of envelop surfaces including the grouping and lofting of swept profiles, and construction of swept volume solids including the combination of swept envelop surface with the ingress and egress surfaces. Experimental results show that the presented algorithm is simpler, more efficient and accurate than other methods.