Abstract: To achieve the automatic completeness inspection of sequential dimensions,a testing method based on locus intersection was proposed.According to the theory of Geometric Constraint (GC) solving and constraint dependency analysis,the completeness testing of sequential dimensioning was transformed into the constrained states determination of Geometric Primitives (GPs).The mapping relationships between the constrained state of GPs,the using state of dimensions and the completeness states of dimensions were established.The concept of locus was proposed to reflect the influence of GC on GPs,and the locus generation rules were built to analyze the locus intersection principles.Based on the location references,the constrained state of each GP was determined in sequence,and the completeness states of dimensions were confirmed.A 3D model with dimensions was taken as an example to demonstrate the process of completeness testing,and the results verified the effectiveness of the algorithm.

Key words: sequential dimensions, completeness state of dimension, dependency analysis, locus intersection, constrained state of geometric primitives

摘要： 为了实现顺序尺寸标注完备性的自动检测,提出一种基于轨迹相交的检测方法。根据几何约束求解和约束依赖性分析,将顺序尺寸标注的完备性检查问题转换为几何基元的约束状态判定问题,建立了尺寸完备性状态与几何基元约束状态、尺寸使用状态之间的映射关系。提出轨迹的概念来反映几何约束对几何基元产生的影响,进而建立了轨迹生成规则,分析了轨迹两两求交的交集类型。以定位基准为基础,依次确定了每个几何基元的约束状态,进而得到了尺寸的完备性状态。以一个含有尺寸标注的三维模型为例,演示了顺序尺寸标注完备性检查的运行过程,结果验证了算法的有效性。

关键词: 顺序尺寸标注, 尺寸完备性状态, 依赖性分析, 轨迹相交, 几何基元约束状态