定性推理在概念设计中的应用

发布时间：2018-03-13 14:10

本文选题：定性推理　切入点：符号有向图　出处：《西安电子科技大学》2012年硕士论文　论文类型：学位论文

【摘要】：概念设计作为产品创新的一个重要环节，受到了越来越多的关注。概念设计作为产品设计整个生命周期的初始阶段，在这个阶段我们所获得关于系统结构的信息是不精确的、不完全的、定性的一些信息，此时我们无法甚至有时候也不需要建立定量的系统模型，因此就不能要用传统的定量方法去分析，而定性推理却能根据这些模糊的信息推出对设计有用的信息，因此将定性推理用在概念设计上有着重要的意义。本文从抽象的角度对产品的概念设计过程进行了进一步的认识，强调了定性推理在概念设计中应用的重要性。在研究了定性推理常用方法的基础上，着重介绍了基于SDG的定性推理方法，它是定性推理的一个重要分支，是一种重要的定性推理方法。本文在总结有关SDG故障诊断研究的基础上，将基于SDG的定性推理方法引入概念设计领域，对基于SDG的定性推理方法进行了系统的研究，，详细研究了SDG定性模型的建立过程以及基于此模型的推理过程，采用基于经验知识为主，以基于数学模型的方法为辅来建立了相应的SDG模型，利用SDG的相容通路，推导出推理规则，从而进行约束传播。通过设计相应的知识表示方法，构造了约束传播和反向推理正向演算算法，结合相应的规则从而实现推理。最后结合平面四杆机构这个问题，采用基于数学模型和基于经验知识相结合的方法建立了相应的SDG模型的以及对反向推理正向演算的过程进行了深入的研究。
[Abstract]:As an important part of product innovation, conceptual design has attracted more and more attention. As the initial stage of the whole life cycle of product design, the information we get about the system structure is imprecise. Incomplete, qualitative information that we can't and sometimes do not need to build a quantitative system model, so we can't use traditional quantitative methods to analyze it. But qualitative reasoning can infer useful information for design according to these fuzzy information, so it is of great significance to apply qualitative reasoning to conceptual design. This paper makes a further understanding of the conceptual design process of products from an abstract point of view, emphasizes the importance of the application of qualitative reasoning in conceptual design, and studies the common methods of qualitative reasoning. This paper introduces the qualitative reasoning method based on SDG, which is an important branch of qualitative reasoning and an important qualitative reasoning method. The qualitative reasoning method based on SDG is introduced into the field of conceptual design. The qualitative reasoning method based on SDG is systematically studied. The process of establishing qualitative model of SDG and the reasoning process based on this model are studied in detail. Based on empirical knowledge, the corresponding SDG model is established with the method based on mathematical model. The inference rules are deduced by using the compatible path of SDG, and the corresponding knowledge representation method is designed. The forward calculus algorithm of constraint propagation and backward reasoning is constructed, and the corresponding rules are combined to realize the reasoning. Finally, the problem of planar four-bar linkage is considered. Based on mathematical model and empirical knowledge, the corresponding SDG model is established and the process of backward reasoning forward calculus is deeply studied.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH122

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