基于GEP语法解析的零件工艺设计意图提取方法

Method for Extracting Intention in Part Process Design Based on GEP Grammar Analysis

为解决现有工艺设计意图捕获方法存在的缺陷,推动实现数控加工工艺中不同力度的工业设计意图的有效复用,提出一种基于GEP语法解析的零件工艺设计意图提取方法。首先,构建以工艺知识为核心的工艺数据结构化模型,将加工操作与特征实现有效关联,提取每个加工操作的设计意图,以实现对工艺数据中每个工步的表征;其次,提出一种不同时刻候选工步下加工操作的工艺设计意图向量化表征方法,进而生成其工艺设计意图的概率分布矩阵。然后,根据企业已有的可以反映不同时刻工艺设计意图的零件工步序列,提取描述工步之间语义与时序关系的上下文无关文法,建立具有层次性、复合性的数控加工工艺知识与或图;最后以工艺知识与或图为引导,根据生成的工艺设计意图概率分布矩阵,基于GEP语法解析联合获得工艺数据中每个工步最优的工艺设计意图。以三轴数控铣削加工零件为研究对象,基于CATIA原型系统,通过实验验证了所提方法的有效性。

In order to solve the shortcomings of the existing process design intent extraction methods and promote the effective reuse of industrial design intent with different strengths in NC machining process,a part process design intent extraction method based on GEP syntax analysis is proposed.Firstly,a process data structured model with process knowledge as the core is constructed to effectively associate processing operations with features,the design intent of each processing operation is extracted,and the representation of each process step is realized in the process data.Secondly,a method for quantifying the process design intention of processing operations under different time candidate steps is proposed,and then the probability distribution matrix of the process design intention is generated.Then,according to the existing part step sequence that can reflect the process design intention at different times,the context-free grammar describing the semantic and timing relationship between the steps is extracted,and the hierarchical and complex NC machining process knowledge and or diagram is established.Finally,guided by the process knowledge and-or graph,according to the generated probability distribution matrix of process design intent,the optimal process design intent of each step in the process data is obtained based on the GEP syntax analysis and combination.Based on the CATIA prototype system,the effectiveness of the proposed method is verified by experiments.