基于实例的齿轮设计应用技术研究

【作者】 孟妍妮；

【导师】 方宗德；

【作者基本信息】 西北工业大学 ， 车辆工程， 2006， 硕士

【摘要】 基于实例推理的设计是一种新的智能设计方法,是基于实例推理技术在设计领域中的应用。基于实例的推理(Case-Based Reasoning)是一种基于记忆、利用过去的实例和经验来解决新问题的一种方法,它可以看作是从一个实例到另一个实例的类比推理。由于CBR具有易学易用,知识获取容易,适应性强等优点,受到人工智能研究者的高度重视。本文主要研究了基于实例设计系统的原理和应用技术,分析了渐开线圆柱齿轮的一般设计过程和方法以及各项特征属性的特点,在此基础上建立了基于实例的设计模型,并将其应用于齿轮的辅助设计,构造了基于实例的渐开线圆柱齿轮辅助设计系统。文本的主要研究内容包括: 1.实例知识的表示 设计实例的表示是基于实例设计系统的基础。本文分析研究了实例知识的表达方法,将实例知识的表达与领域知识相结合,并利用面向对象的思想,提出了有效的模型简化和特征抽取方法,抽象出渐开线圆柱齿轮的实例结构,采用结构化模型描述应用领域知识。 2.实例的组织 本文借鉴面向对象的思想,提出了具有多重抽象层次的分类结构组织实例,将整个实例库划分为多个层次上的子空间,能够在实例检索过程中有效地限定搜索范围,提高检索效率。 3.实例检索方法研究 实例间相似度的计算方法和实例检索策略是CBD系统中的重点。本文将自适应人工神经网络应用于CBD系统,构建了两级ART网络模型,可以完成实例的动态聚类,并能自动地将实例组织成两级存储结构,提高了系统的工作效率。本文在研究现有的实例间相似度算法的基础上,结合渐开线圆柱齿轮自身的设计特点提出了新的计算实例间相似度的方法。 4.实例调整技术研究 实例调整是CBD系统中的难点,本文深入分析了现有的实例调整方法,将基于规则的修改方法和基于实例的修改方法结合起来,提出了适合于本系统的实例调整的策略和具体实现方法。 5.基于实例的设计系统本文最后重点阐述了建立基于实例知识的渐开线圆柱齿轮设计原型系统的具体实现过程和实验分析,对CBD技术在渐开线圆柱齿轮设计方面的具体应用作了的探索。更多还原

【Abstract】 Case-Based Design is a new kind of intelligent design method and the appliance of CBR in design. Case-Based Reasoning is a memory-based method which utilizes old cases and experience to solve new problem, and it can be seen as analogism from a case to another case. Because CBR has much merit such as easily learning and using, facilitated knowledge acquirement, strong adaptability etc, it gets highly regard of artificial intelligence researcher. This paper focuses on the research of CBD system principium and application. After analyzing the main ideas of case-based design and the features of the involute cylinder gear, a prototype system for the involute cylinder gear design is developed. The following are the main research contents:1.Representation of design cases Representation of design cases is the basis of case-based design system. The paper analyzes the Representation of cases and the technology of object-oriented. The paper analyses the features of the involute cylinder gear and brings forward a special model-simplified and feature abstract method to structurize the representation of cases.2.Organization of design cases This paper adopts the technology of object-oriented and realizes a classification hierarchy with multi-abstract layers to organize cases. The advantage of this method is that its ability to divide the whole case base into several subspace so as to limit the searching bounds, which can improve the retrieval efficiency. On the basis of research the matching algorithms, the paper provides a new matching algorithm.3.Research on case retrieval Case retrieval algorithm and similarity calculation are the most important issues for current research in CBD. This paper combines ART-2 Neural Networks and multi-grade index and presents a two-level networks model for cases. This method can achieve dynamic clustering and progressively reduce the searching space to improve the adaptive capability and the efficiency of the system.4.Case Adaptation Strategy Case Adaptation Strategy full of difficulties in CBD. This paper analyzes several methods of case modification, and puts forward amethod to integrate CBR and RBR into the process of case modification which is fit for this CBD system.5. Research on the Case-based Design System This paper discusses the application of CBD technique in Involute Cylinder Gear Design system to explore for the practical application of CBD technique in mechanical field.更多还原