基于CBR的车身焊接夹具CAD系统开发

发布时间：2018-02-06 05:15

本文关键词： 焊接夹具智能化设计基于实例推理二次开发 CATIA　出处：《江苏大学》2017年硕士论文　论文类型：学位论文

【摘要】：现有汽车车身焊接夹具设计开发很难继承以往专家的经验与知识,制约了汽车车身焊接夹具的开发效率和产品质量,因此开发出一款基于实例推理的车身焊接夹具智能化CAD系统进行汽车车身焊接夹具快速开发具有重要意义。本文以基于实例推理为中心,开发出一款基于实例推理车身焊接夹具CAD系统,其主要研究内容与进展情况如下:(1)在深入研究车身焊接夹具的分类与特点之后,提出基于车身焊接夹具的CBR-CAD思想,根据需求分析,构建出系统框架共七大模块:用户管理模块、用户工作空间模块、基于实例推理模块、焊接夹具标准件库模块、快速装配模块、2D工程图模块、BOM管理模块。之后对CATIA文档结构和命令交互机制做出剖析,并选择CAA方式作为开发模式。(2)分析了基于实例推理的原理和特点,重点研究了基于车身焊接夹具实例推理关键技术。特别是在实例表达方面,在以往使用对象模型来创建对象的基础上,引入“池”的概念来创建对象,所有的相关数据分布在关系池、规则池、参数池和方法池中,加快了创建对象速度。在实例提取方面,首先构造出车身焊接夹具实例提取决策树,然后在实例检索方面使用最近邻算法来进行实例检索,并通过实例验证了检索的有效性,之后对实例的冲突解决和实例组织做了论述。(3)结合CAA框架,对CATIA中如何进行参数化进行分析,最终确定了基于知识工程的参数化技术。以数据库作为载体,分析了标准件创建的思路,开发出标准件库,并能使用CAA框架实时读取知识工程的参数,修改并重建模型。最后,以L座为例详细说明了如何操作数据库对数据进行检索、过滤和排序。(4)对基于实例推理车身焊接夹具CAD系统进行了完整测试,并以车身侧围焊接夹具为例说明了系统各个模块的工作流程,验证了该系统的可行性和有效性。
[Abstract]:It is very difficult to inherit the experience and knowledge of previous experts in the design and development of welding fixture for automobile body, which restricts the development efficiency and product quality of welding fixture for automobile body. Therefore, it is important to develop an intelligent CAD system for automobile body welding fixture based on case-based reasoning (CBR). This paper focuses on Case-Based reasoning (CBR). A case-based reasoning (CBR) welding fixture CAD system is developed. The main research contents and progress are as follows: 1) after deeply studying the classification and characteristics of body welding fixture. This paper puts forward the idea of CBR-CAD based on body welding fixture. According to the requirement analysis, seven modules of the system framework are constructed: user management module, user workspace module, and case-based reasoning module. Welding fixture standard parts library module, fast assembly module 2D engineering drawing module and BOM management module. Then the CATIA document structure and command interaction mechanism are analyzed. The principle and characteristics of CBR are analyzed, and the key technology of CBR based on welding fixture is studied, especially in case representation. Based on the previous use of the object model to create objects, the concept of "pool" is introduced to create objects. All the relevant data are distributed in relational, rule, parameter and method pools. In the aspect of instance extraction, the decision tree of instance extraction for body welding fixture is constructed first, and then the nearest neighbor algorithm is used to retrieve the case in the aspect of case retrieval. The effectiveness of the retrieval is verified by an example, and then the conflict resolution and case organization of the case are discussed. (3) based on the CAA framework, how to parameterize the CATIA is analyzed. Finally, the parameterized technology based on knowledge engineering is determined. With the database as the carrier, the idea of creating standard parts is analyzed, and the standard part library is developed, and the parameters of knowledge engineering can be read in real time by using CAA framework. The model is modified and reconstructed. Finally, taking the L block as an example, it explains in detail how to operate the database to retrieve the data. Filter and sort. 4) the CAD system of body welding fixture based on case-based reasoning is tested, and the work flow of each module of the system is illustrated by the example of side welding fixture. The feasibility and effectiveness of the system are verified.
【学位授予单位】：江苏大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP311.52;U468.2

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