基于零件三维模型对称性识别的三维尺寸自动标注技术

3D Dimension Automatic Annotation Technology Based on Part Symmetry Detection

为了解决目前三维尺寸自动标注中对于模型对称性的判断主要依赖交互选择以及存在的算法普适性问题,以B-Rep表达模型为研究对象,面向尺寸的自动标注,研究了模型的对称性识别,并将对称性识别与尺寸快速标注技术相结合,实现了三维模型尺寸的自动标注。首先运用分治思想将对称性判断问题转化为对称面的匹配问题,通过对匹配面集与模型之间的布尔运算来判断全局对称性;然后结合尺寸标注实际情况,对冗余尺寸进行了总结与合并,以达到标注完备性与合理性要求;最后以实验室自研MBD软件为平台,基于openCASCADE实现了上述算法,开发了对称性识别以及尺寸自动标注模块,并通过实例模型与SolidWorks的DimXpert尺寸自动标注插件进行了标注效果对比,验证了该方法的可行性。

To address the issue of reliance on interactive selection and algorithm universality in current automatic 3D dimension annotation systems for model symmetry detection,this paper focuses on size⁃based automatic annotation using B⁃Rep models and researches symmetry detection for the model,integrating symmetry detection with rapid size annotation technology to achieve automatic 3D model size annotation.Firstly,using the principle of divide and conquer,the symmetry detection problem is transformed into a matching problem of symmetrical faces,and global symmetry is determined through Boolean operations between the matching face set and the model.Then,taking into account the practical situation of size annotation,redundant dimensions are summarized and combined to achieve completeness of annotation.Finally,the proposed algorithm is implemented on the MBD software platform developed by the laboratory,and a symmetry detection and automatic size annotation module are developed,verifying the feasibility of the algorithm.