基于本体的机械产品工程变更影响分析方法研究

发布时间：2018-04-30 16:11

本文选题：工程变更 + 本体　；参考：《山东大学》2015年博士论文

【摘要】：制造企业在产品设计和制造过程中,不可避免地出现大量工程变更。多数企业对已完成的变更没有很好地利用,对变更的影响分析大都依靠人的经验完成,处理效率较低,分析结果不全面,致使变更决策失误或后续变更执行不到位。本文创建了工程变更案例知识的本体,提出了相似变更案例的检索策略和算法,从变更影响范围和影响程度综合分析变更影响,提出了基于产品结构关联、功能关联和外部因素关联的变更影响范围分析方法,构建了基于成本、时间、效益和风险的变更影响程度评价体系。本文的研究成果必将为提升企业变更分析的能力和效率,增强企业市场竞争力起到积极的理论指导和应用推动作用。提出了利用本体实现变更案例表示的方法,结合变更案例知识特点,将其抽象为变更对象、变更流程、变更数据和变更组织四类基本概念,建立了概念体系,定义了概念属性和概念间关联关系。实现了变更案例的统一表示,满足了变更管理者对案例重用的基本要求,为案例检索和影响分析奠定了基础。提出了变更案例的检索策略,建立了基于本体的语义相似度改进计算模型。通过案例标引,将检索转变为检索需求与变更案例标引的匹配,提高了检索效率。在对检索需求进行概念扩展和约束关系定义后,选择向量空间模型作为检索模型,在计算概念的属性相似度基础上结合概念自身的相似度获得变更案例与检索需求的综合相似度值,保证最大程度上把握用户检索需求,更快速准确地提供相似变更案例,提高用户分析变更的效率和质量。提出了基于本体的工程变更影响范围分析方法和实现策略。在研究变更传播机制的基础上,分别从产品零部件间的结构关联、功能关联和其他外部因素三方面分析变更影响范围,基于本体的图模型搜索算法,确定变更影响到的产品/零部件对象、图文档等数据、相关责任人及过程/活动,为进一步进行变更影响程度分析、变更决策及保证变更实施的全面性和一致性奠定基础。创建了工程变更影响程度评价体系。构建了变更成本、变更时间、变更效益和变更风险的评价指标体系,提出了指标值的获取方式和计算方法以及变更影响程度的综合评价原则。变更管理者可针对不同类型的变更活动筛选细化评价指标,从所关注的角度对变更实施进行评价,实现变更实施的事前预测,为变更决策提供依据。在上述理论和方法研究的基础上,设计实现了工程变更影响分析系统。该系统基于PLM系统设计开发,实现了变更案例、设计知识和相关领域知识的检索,基于本体的变更影响范围分析,基于成本、时间、效益、风险的变更影响程度分析,并以汽车的零部件变更为例进行了应用验证。
[Abstract]:In the process of product design and manufacturing, a large number of engineering changes inevitably occur in manufacturing enterprises. Most enterprises do not make good use of the completed changes, the impact analysis of the changes mostly depends on the human experience, the processing efficiency is low, the analysis results are not comprehensive, resulting in the error of the change decision-making or the implementation of the subsequent changes is not in place. In this paper, the ontology of engineering change case knowledge is established, and the retrieval strategy and algorithm of similar change case are put forward. Based on the analysis of the scope of influence of change based on the correlation of function and external factors, the evaluation system of change influence degree based on cost, time, benefit and risk is constructed. The research results of this paper will play a positive role in theory guidance and application for improving the ability and efficiency of enterprise change analysis and enhancing the market competitiveness of enterprises. In this paper, a method of realizing change case representation by ontology is put forward. According to the characteristics of change case knowledge, it is abstracted into four basic concepts: change object, change process, change data and change organization. The relationship between conceptual attributes and concepts is defined. It realizes the unified representation of change cases, meets the basic requirements of case reuse by change managers, and lays a foundation for case retrieval and impact analysis. The retrieval strategy of change case is proposed, and the improved semantic similarity calculation model based on ontology is established. Through the case indexing, the retrieval is transformed into the matching between the retrieval requirement and the change case indexing, and the retrieval efficiency is improved. After extending the concept and defining the constraint relation, the vector space model is selected as the retrieval model. On the basis of calculating the attribute similarity of the concept, combining the similarity of the concept itself to obtain the comprehensive similarity value between the change case and the retrieval requirement, it ensures that the user's retrieval needs are grasped to the greatest extent, and provides the similar change case more quickly and accurately. Improve the efficiency and quality of user analysis of changes. The analysis method and implementation strategy of the influence range of engineering change based on ontology are put forward. On the basis of studying the mechanism of change propagation, this paper analyzes the scope of influence of change from three aspects: structural association, functional association and other external factors, and the graph model search algorithm based on ontology. To determine the product / parts objects, drawings and documents, related responsible persons and process / activities, which will lay the foundation for further analysis of change impact degree, change decision and ensure the comprehensiveness and consistency of change implementation. The evaluation system of influence degree of engineering change is established. The evaluation index system of change cost, change time, change benefit and change risk is constructed, and the method of obtaining index value and calculating method and the comprehensive evaluation principle of change influence degree are put forward. The change manager can screen and refine the evaluation index according to different types of change activities, evaluate the change implementation from the point of view of concern, realize the prior prediction of the change implementation, and provide the basis for the change decision. On the basis of the above theory and method research, the project change impact analysis system is designed and implemented. The system is designed and developed on the basis of PLM system. It realizes the retrieval of change case, design knowledge and related domain knowledge, the analysis of change influence range based on ontology, the analysis of change influence degree based on cost, time, benefit and risk. The application verification of automobile parts change is carried out.
【学位授予单位】：山东大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TH186

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