【作者】 高伟；

【导师】 殷国富；

【作者基本信息】 四川大学 ， 机械制造及其自动化， 2005， 博士

【摘要】 工艺知识是产品设计制造过程中一种重要的企业知识资源,是制造企业信息化技术系统的重要组成部分之一,也是实现工艺设计信息系统智能化的核心与关键。但由于工艺知识本身的多样性、复杂性、经验性、不确定性等特点,致使企业中的工艺知识缺乏有效的归纳和整理,知识的重用性和共享性差。如何将工艺知识形式化、数字化并以显式的方式保存下来,是工艺设计信息系统智能化研究的前沿问题之一。 随着企业信息化进程的推进,计算机辅助工艺设计(CAPP)系统在制造企业得到广泛的应用,制造企业积累了大量的以Word文档、电子表格、工艺卡片等电子文档形式存在的工艺设计数据,这些数据是企业工艺人员智慧的结晶,蕴涵有大量的工艺知识。如何从这些具有多种结构形式的数据资源中发现、获取和重用其中蕴涵的工艺知识也是网络化环境中工艺设计信息系统智能化急需解决的一项关键技术。本论文在国家自然科学基金项目的资助下,应用数据挖掘理论,重点研究面向工艺设计信息系统的工艺知识描述、分类、发现以及重用的基本原理和在计算机网络环境下的实施算法,探讨一种为制造企业积累工艺知识、提高工艺设计信息系统智能化水平的技术方法。本文的研究成果和特色如下: (1) 分析了基于知识的工艺设计信息系统的智能体现及其与传统智能化工艺设计信息系统的区别,提出了面向用户、面向角色、面向任务的集成化安全管理模型,进而构建了基于知识的工艺设计信息系统的体系结构。为了支持工艺知识发现,建立了集成管理特征、几何特征、材料特征、精度特征、装配特征、工艺特征的零件工艺信息模型。 (2) 提出了基于数据挖掘技术的工艺知识分类方法,将工艺知识分为由标准工艺术语、工艺元、工艺模板、工艺实例等组成的重用型工艺知识和由加工方法选择规则、加工设备选择规则、加工参数选择规则、工时定额和工艺路线安排规则等组成的决策型工艺知识两种类型。根据这两种工艺知识内容的结构特点,分别定义了它们的关系型数据库存储模型,并构建了集成知识收集、管更多还原

【Abstract】 Process knowledge is an important enterprise knowledge resource in product designing and manufacturing and an indispensable part of information technology system in manufacturing industries. It is also the core and key element in realizing the intelligence of process planning information system. However, owing to the diversity, complexity, experience, uncertainness, etc., and other characteristics of process knowledge, the process knowledge in enterprises is in need of effective generalization and arrangement, which makes it hard to be reused and shared. How to formalize and digitalize the process knowledge so as to preserve them in explicit forms is one of the front studies in intelligence of process planning information system.With the progress of enterprise informationization, Computer Aided Process Planning (CAPP) system has been widely applied in manufacturing industries, which has accumulated a large quantity of process planning data in forms of Word, Excel, Cards and other electronic documents. These planning data is the crystallization of the experts and contains a vast of process knowledge. How to discover, acquire and reuse the implied process knowledge from these various-structured data is an important and urgent problem in the intelligence of process planning information system. Supported by the project of national natural science fund and by adopting Data Mining theories, this research focuses upon the basic principles of process knowledge description, classification, discovery and reuse in the orientation of process planning information system, and the implementation arithmetic in computer network environment of these principles, so as to explore a technique to accumulate process knowledge and increase intelligence level of process planning informationsecurity management model in the orientation of user, role and task is presented. The architectural structure of knowledge-based process planning information system is further established. In order to support the discovery of process knowledge, a part process information model is set up, which is an integration of such features as management, geometry, material, precision, assembly and process.(2) A process knowledge classification method is presented based on Data Mining technique. Process knowledge is classified into reusable process knowledge and decisional process knowledge. The former is composed of standard process term, process unit, process template and process case, the latter is constituted of selection rules for processing means, process equipment, process parameters and man-hour ration, process routes arrangement, etc. According to the structural characteristics of these two kinds of process knowledge, the relational databases storage models are defined respectively and the functional models of process knowledge repository administration system is constructed which integrates knowledge-collecting, management and service.(3) An improved hierarchical agglomerative method is designed to make a clustering analysis of the process data according to the features of process data. On this basis, a standard sentence-acquisition method is put forward through editing distance measurement of similarities between different classifications; A double-level process document model is constructed, which is composed of process procedure and steps, to measure the similarities of process documents and carry out clustering analysis on process data so as to acquire process cases.(4) The problem of knowledge discovery in sequence pattern is discussed, and process document is simplified into process sequence, and then a formalized definition is given. By combining Apriori arithmetic and the processing sequence in working procedure, Apriori-seq arithmetic is designed to mine the process sequence pattern so as to acquire process unit and process template.(5) To store the process decision data samples by Process Decision Data Table (PDDT). Designed an improved process decision tree studying arithmetic based on CLS (Concept Learning System). Measuring the importance of conditional attribute for process decision rule in PDDT by ID3 (Iterative Dichotomizer 3) algorithm. Accordingly a process decision tree is established, the principle of simplified disposal of process decision tree is put forward and the method of transformation from process decision tree to process decision regulations is presented.(6) A Directed Assembly Relation Graph (DARG) is defined orienting process cases searching. A case searching algorithm based on DARG is designed for parts with complex assembly restrictions. A Formal Part Query Language (FPQL) is defined, based on which a speedy process case searching algorithm is put forward for parts with simple assembly restrictions.(7) A general goal and functional model are put forward in accordance with the development and requirement of process planning information system in JiaJiang Hydraulic Engineering Machinery Factory (SGCAPP). By adopting process data formalization, and based upon XMLlocal data exchange and Plug-in, a software system is developed which is composed of project management module, flow management module, resource management module and process planning module. To realize process knowledge administration of process unit, typical process and process case, etc. in process resource management module and thus the separation of knowledge administration and application is realized. SGCAPP system has achieved favorable results in enterprise practices and was checked and accepted in April 2005.更多还原