汽车焊装夹具案例知识获取的研究

发布时间：2018-11-03 16:37

【摘要】：现代产品设计是基于知识的设计,以知识获取为核心,因此设计重用研究成为设计领域一个研究热点。汽车白车身工程中焊装夹具的设计重用研究,已成为一个重要的研究应用领域。一个轿车的白车身装焊工艺过程包含3000~5000个点焊步骤,有100多个焊装工位,500~800套夹具单元。如何利用已有大量的汽车焊装夹具零部件文件进行新的设计任务,成为此领域的一个非常有意义的研究课题。基于案例推理的设计是指从三维装配模型设计案例中,进行案例知识学习、知识获取,从三维模型中提取运动学模型,进而辨识典型模型的主要参数,建立三维模型装配案例参数模型,通过案例检索、案例修改实现案例重用的设计。基于实体特征的案例辨识方法,改变了以往通过文本名称等非实体特征检索辨识夹具类型的方法。因此,本文以基于特征的夹具案例辨识算法为研究内容。在基于实体特征的夹具案例辨识理论框架的支持下,本文首先详细研究了典型焊装夹具案例辨识理论;在此基础上提出了典型夹具案例中一节转臂夹具单元和二节转臂夹具单元关键零件辨识算法;进而实现了典型夹具案例类型的辨识算法和典型夹具案例的运动学模型提取算法。最终通过工程实例,对汽车焊装夹具案例辨识算法进行验证,基于实体特征的案例辨识算法研究,将为实现典型夹具案例中零件的辨识和典型夹具类型的辨识提供解决方案。本文提出的基于实体特征的夹具案例辨识算法,可进一步推广到一般三维装配案例的辨识和案例运动学模型的提取上。
[Abstract]:Modern product design is based on knowledge, with knowledge acquisition as the core, so the research of design reuse has become a research hotspot in the field of design. The design and reuse of welding fixture in automobile white body engineering has become an important research and application field. The welding process of a car includes 3000 ~ 5000 spot welding steps, with more than 100 welding stations and 500 or 800 fixture units. How to make use of a large number of automobile welding fixture parts files for new design tasks has become a very meaningful research topic in this field. Case-based reasoning (CBR) design refers to the case knowledge learning, knowledge acquisition, kinematics model extraction from 3D assembly model design cases, and identification of the main parameters of typical models. The case parameter model of 3D model assembly is established, and the design of case reuse is realized by case retrieval and case modification. The case identification method based on entity feature changes the previous method of identifying fixture type by non-entity feature retrieval such as text name. Therefore, the feature-based fixture case identification algorithm is studied in this paper. Supported by the framework of fixture case identification based on entity feature, this paper firstly studies the typical welding fixture case identification theory in detail. On the basis of this, the identification algorithms of key parts of one and two arm jig units in typical fixture cases are proposed, and the identification algorithm of typical fixture case types and kinematic model extraction algorithm of typical fixture cases are realized. Finally, the case identification algorithm of automobile welding fixture is verified by an engineering example. The case identification algorithm based on entity features will provide a solution for the identification of parts and typical fixture types in typical fixture cases. The algorithm of fixture case identification based on solid feature in this paper can be extended to the identification of general 3D assembly cases and the extraction of case kinematics model.
【学位授予单位】：烟台大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG431

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