复杂结构件CAD模型碎面缺陷自动识别与修正方法

An Automatic Fragment Face Error Recognition and Correction Technique for Complex Structural CAD Model

针对复杂结构件数模中常存在碎面缺陷,易导致零件在数控加工自动编程时出现特征识别错误、特征提取困难等问题,提出基于属性邻接图的自动识别与修正方法.首先分析复杂结构件碎面缺陷的特征,给出碎面缺陷的定义;然后建立结构件CAD模型的有效属性邻接图,计算面和边的属性并对图中元素赋值,识别碎面缺陷;再根据碎面的几何类型和几何参数构造相应类型的基面,并对基面进行拟合完成碎面缺陷的修正;最后给出文中方法的实现流程并开发了相应的算法,结合实例证明了该方法的正确性和有效性.文中算法已在CATIA V5平台上实现,并集成在飞机复杂结构件快速数控编程系统中,应用于实际生产,取得了良好的效果.

There are always fragment errors in complex structural CAD model,which is prone to bringing troubles into the successive machining operations.To solve this problem,an automatic fragment face error recognition and correction technique based on attribute adjacency graph is proposed.First,the characteristics of fragment face error in complex structural model are analyzed and the definition of the fragment face.error is given.Second,the attribute adjacency graph of the structural part model is constructed.And the attributes of the faces and edges of the graph are calculated to assign the values to elements of the graph.Next,the fragment face error is identified in the form of extended attribute adjacency graph.Then,the relative basic surface of fragment face error is constructed based on its geometric type and parameters.And the basic surfaces are fit to correct the errors.Finally,the algorithm flow of this technique is given and implemented.The experimental results are showed to prove that the presented method is both correct and effective.