基于知识的航空产品装配单元划分技术研究

【作者】 李丽萍；

【导师】 李原；

【作者基本信息】 西北工业大学 ， 航空宇航制造工程， 2005， 硕士

【摘要】 系统地提出了基于知识的航空产品装配单元划分的理论与方法,对装配工艺知识的获取、知识的表示、主体装配单元划分、未组合件划分等关键技术进行了深入的研究。在理论研究的基础上,开发了基于知识的装配单元划分原型系统,支持工艺人员进行快速工艺设计。 全文主要工作如下: 第一章给出了装配单元及装配单元划分的含义;从图分解法、模糊数学法及其他装配单元划分方法三方面入手,对国内外现有装配单元划分技术的研究与应用现状进行了综述与分析;论述了在飞机产品中进行基于知识的装配单元划分的研究意义、研究背景及本论文的研究内容。 第二章分析了飞机装配单元划分在飞机装配工艺设计中的重要地位;构建了飞机图树装配模型,并研究了数学表达;总结了装配单元的划分特点及分离面的选取原则;重点分析影响装配单元划分的定量与定性因素,提出采用模糊数学的方法加以解决;并从知识及对各因素的可控角度分析,确定装配基准、连接方法、典型接合与对接接头对装配单元划分的影响。 第三章提出了面向对象的知识模型,结合飞机产品特点,提出了面向对象与产生式规则相结合的知识表示方法;以装配工艺快速设计支持系统的知识库结构为基础,明确了装配单元划分系统知识库中实体间联系;阐述了知识的正向推理策略及冲突消解策略。 第四章提出了分主体装配单元划分和未组合件划分两步进行、中间穿插知识的解决装配单元划分的核心思想;以树模型为基础,通过实例知识的运用解决主体装配单元划分,以图模型为基础,通过构造关联图上的聚合度,运用模糊综合评判的方法实现了对未组合件的划分。 第五章介绍了基于知识的装配单元划分原型系统的设计与开发。采用VC++与CAA(Component Application Architecture)的集成开发工具,实现了运行于CATIA环境下的装配单元划分系统。 第六章对本文工作进行了总结,讨论了进一步研究的可能方向。更多还原

【Abstract】 This dissertation presents a new theory and method of assembly unit partition based on the knowledge. Research of the key techniques of assembly unit partition includes the assembly knowledge acquisition and representation, the main assembly unit partition and the unassembled partition. On the basis of the theoretical research, an assembly unit partition system based on the knowledge is developed, which can support the technologist in getting feasible assembly technological of product quickly.The dissertation is organized as follows:Chapter 1 gives the definition of assembly unit and assembly unit partition; gives a review of the development situation of assembly unit partition method, which from chart disassembly, fuzzy mathematics and other three aspects; And the background, significance and contents of assembly unit partition are proposed particularly.Chapter 2 analyses the importance of aircraft assembly unit partition; gives a model called aircraft chart-tree assembly model, and its mathematics representation; expatiates some factors which effects assembly unit partition. Presents fuzzy theory to solve the problem made by ration factors and other factors; after the analysis of the knowledge and factors controllable, ascertain the effect made by assembly benchmark, link method, typical joint and tie-in.Chapter 3 presents the object-oriented knowledge model, gives the knowledge representation method which combing the object-oriented with generation rule; ascertains the relation between entities in knowledge base of assembly unit partition; expatiates the reasoning policy and conflict solution policy.Chapter 4 presents make two steps to finish the assembly unit partition, which are the main assembly unit partition and unassembled partition, interlude using knowledge. The main assembly unit partition is to mach tables of the bill of material, and unassembled partition is to search liaison between parts, compute assembly polymerization.Chapter 5 gives the general architecture of a prototype system for assembly unit partition based on knowledge under the CATIA environment to validate the ideas and methods proposed in this dissertation. By using VC++ and CAA, four sub-modules are developed and implemented. A practical case is used to validate the correctness and effectiveness of the research results.Chapter 6 draws some conclusions and the future directions in the field.更多还原