【作者】 张立文；

【导师】 黄传真；

【作者基本信息】 山东大学 ， 机械电子工程， 2005， 硕士

【摘要】 在企业实现CAD/CAPP/CAM/PDM/ERP等系统集成与数据信息共享的过程中,CAPP是连接产品设计与制造的桥梁。但CAPP的研究与应用相对滞后,传统的CAPP系统已成为实现CAD/CAPP/CAM等系统集成的瓶颈。因此有必要研究与开发新的CAPP系统。 本文以半创成式工艺设计方式自动生成零件多工艺路线,并根据评价原则对工艺路线进行优化,获得最优工艺路线为目标,对其实现过程中的关键技术进行研究,并以WIT-CAPP为开发平台,开发了基于设备资源和成本约束的动态工艺路线创成式CAPP子系统。 建立了创成式CAPP子系统的体系结构模型,该模型由零件信息输入、工艺知识库和推理机组成。提出了基于特征的方位特征描述法,实现了对回转体类和非回转体类零件特征的描述。建立了零件工艺信息结构模型,提出了形状特征中主特征和辅特征的划分原则,建立了形状特征层次结构模型和数据结构模型,采用特征标识和特征编码相结合的方法来描述形状特征。建立了适应动态变化环境的系统事实库和工艺规则库。研究了特征加工链的特征工序数即加工链的长度,建立了单特征加工链的数据结构模型。研究了推理策略和推理方式,以及解决推理过程中冲突的解决方法,采用基于规则的正向推理策略,采用规则优先级的方法解决了规则冲突。采用了子目标法和空间划分匹配法来对工艺路线决策中的推理模块进行分解,通过一系列的推理过程完成动态工艺路线的创成设计。建立了基于规则和推理机的工艺决策模型,该模型的优点是使工艺决策规则和工艺数据相互独立,工艺决策规则与系统推理机程序相互独立。提出了多工艺路线的串/并联图表示方法,建立了最优工艺路线的评价原则和最优工艺路线评价函数。并对系统进行了实例运行。论文的研究结果对推动CAPP技术的发展和应用具有一定的理论和现实意义。更多还原

【Abstract】 Computer aided process planning (CAPP) is the linkage between design and manufacture in the course of software integration and data share among CAD/CAPP/CAM/PDM/ERP etc.. But the application and research of CAPP is very slow. The traditional CAPP system has become a bottleneck in the integration of CAD/CAPP/CAM. Therefore, it’s necessary to study and develop a new kind of CAPP system.The thesis aims at automatic-achieving several technology processes by semi-generated technology planning, and optimizing the technology processes in accordance with the proposed evaluating rules to get the best technology process. And the key technology to reach the aims is researched. A generated system for dynamic technology process based on machine resource and cost constraint has been developed on the base of WIT-CAPP.The general structure model of generated-system for CAPP is built, which is composed of the input of part information, the knowledge database of process planning, and process decision and reasoning module. The geometry features on rotating parts and other kinds of parts are described with the proposed orientation and feature description method. The information model of part technology process is designed, and the rules are raised to classify the primary shape feature and the secondary shape feature. The layer structure model of shape feature and data structure is established. The shape feature is described by the combination of feature mark and feature code method. The system fact information database and technology rule database are designed, which are suitable for the changing manufacture environment. The feature number of working procedure, i.e. the length of feature operation chain, is studied, and the data structure model of single feature operation chain is designed. The reasioning strategy and mothed, and the solution to the conflict arised in the course of reasoning is studied. The forward reasoning strategy based on rules is adopted, the rule confliction is resolved with the preference rule. The reasoning course of technology process strategy is decomposed with subordinate aim and space separation matching method. The dynamic technologyprocesses are generated with a series of reasoning process. The decision-making model of technology based on rules and reasoning is built, whose merits are that the technology decision-making rules, technology data and reasoning program is independent each other. The series-parallel connection chart is designed to describe the multipule technology processes, and the evaluating rules and function for optimizing technology process are also designed. The system is operating with a real part example. The study result of the thesis is of theoretical and practical singnificance to promote the development and application of CAPP technology.更多还原