【作者】 马铁强；

【导师】 孙伟；

【作者基本信息】 大连理工大学 ， 机械设计及理论， 2009， 博士

【摘要】 随着制造业市场需求向多品种小批量定制方向转变,大规模定制逐渐成为企业生产模式的发展方向。产品快速设计作为一种面向大规模定制的产品设计技术,是实现大规模定制的核心和源头,其关键是合理组织、管理以及重用企业设计资源,通过设计资源优化和重组,设计出客户满意的产品。CAD模型作为一类重要的设计资源,其数量随着三维CAD技术推广而剧增。为了解决CAD模型重用问题,使之为产品快速设计和建模服务。论文研究了支持产品快速设计的CAD模型重用技术,并围绕面向产品快速设计的产品族建模、CAD模型检索以及异构CAD系统数据交换等关键技术开展研究。具体内容如下:(1)根据CAD模型的结构、功能及工程特性,分析CAD模型的可重用性和重用层次;以CAD模型可重用性和重用层次为基础,建立支持产品快速设计的CAD模型重用技术框架,并分析其关键技术构成情况。分析面向产品快速设计的产品族建模、CAD模型检索、异构CAD系统数据交换等关键技术存在的问题,并给出相应解决途径。(2)为了满足成熟产品快速设计系统开发的要求,利用模块化设计思想建立了面向产品快速设计的产品族结构模型,并给出其建模方法及过程。以成熟产品设计实例为分析对象,利用产品结构标号图描述其装配结构;提出基于频繁子图挖掘的产品族模块划分方法,建立频繁子图到产品族模块的映射关系;研究了产品族结构关联方法,包括产品族装配结构预定义、产品族配置关系定义和产品族参数关系定义。提出的产品族建模方法用于快速建立成熟产品快速设计系统所需的产品族,可有效缩短成熟产品快速设计系统的开发周期,同时实现CAD模型的装配层重用。(3) CAD模型检索技术是实现CAD模型重用、提高设计效率的有力工具。为了提高CAD模型检索工具的智能化、可视化水平,论文以边界匹配为基础,提出基于拓扑邻接逼近的CAD模型检索方法。该方法分为两步:以基于广度优先搜索的图生成树算法获得检索对象与检索条件之间的初始边界匹配方案;提出拓扑邻接逼近算法,并以初始边界匹配方案作为输入,搜索检索对象与检索条件之间最佳边界匹配方案。以最佳边界匹配方案为依据,计算检索对象与检索条件之间的结构相似性,从而实现CAD模型检索。该方法已被应用于UG系统,可实现“~*.prt”模型文件检索。实验表明,该方法比其他方法的精度、效率更高,适应性更强,实用性更好。(4)为了实现协同产品快速设计中异构CAD系统间的模型转换与重用,提出了基于特征的异构CAD系统集成数据交换方法。建立了该方法的框架,并分析其实现机制;从特征层次分析CAD模型信息构成,提出基于特征类的特征信息描述方法,提出改进的几何证书标识法解决几何元素命名与辨识问题;给出异构CAD系统数据交换过程中的设计历史、特征以及约束等设计意图信息转换方法。该方法被应用于CATIA系统和UG系统之间的数据交换过程。实验表明,该方法可有效解决协同产品快速设计中的CAD模型共享、转换与重用问题。该方法与其他方法相比,其信息丢失更少,目标CAD模型与源CAD模型具有相同变型效果。(5)提出了基于CAD模型重用的产品快速设计系统开发方法。建立了基于CAD模型重用的产品快速设计系统框架,并分析其功能模块;以卧式冷凝器设计为例,阐述了基于产品族的产品快速设计、结构相似模型检索与重用、异构CAD模型转换与重用标准件模型管理与重用等关键技术的实现方法及应用实例。该系统已在某制冷企业应用,为企业取得了良好的经济效益。最后对全文的主要研究内容及创新点进行总结,并提出进一步研究设想。更多还原

【Abstract】 With the market demand changing to low-volume and high-variety,the mass customization becomes the trend of production mode gradually.As a kind of product design technology facing mass customization,product rapid design is the kernel technology realizing mass customization.The key factor is the organization,management and reuse of design resource,while enterprises implement the product rapid design.The product meeting the costumer’s demand is designed with the optimization and recomposition of design resource, while the product rapid design is implemented.As a kind of important design resource,the number of CAD models increase rapidly with the broadly application of 3D CAD systems.In order to reuse CAD models and serve product rapid design,the reuse of CAD models supporting product rapid design is researched. Some key technologies are researched,such as the product-rapid-design-oriented product family modeling,CAD model retrieval and data exchange between heterogeneous CAD systems.The work of this dissertation is as follows.(1) The reusabilities and reuse levels of CAD model are analyzed according to the characteristics of it.The theoretical system of CAD model reuse technologies supporting product rapid design is built accoding to the reusabilities and reuse levels of CAD model.The constitutions of key technologies in the framework are analyzed.The problems in some key technologies are put forward,and these key technologies include the product-rapid-design-oriented product family modeling,CAD model retrieval,and data exchange between heterogeneous CAD systems.The corresponding solutions are given.(2) In order to develop the rapid design system of the developed product rapidly,the the product-rapid-design-oriented product family structure model is built,and the modeling method are put forward based on modularizing design.The expression of assembly structure based product structure labeled graph is proposed.The module partition method based on frequent subgraph mining is presented,and Apriori algorithm is applied to build the mapping between frequent subgrahs and product family modules.The structural correlation method of product family is presented,which includes the predefinition of the assembly structure of product family,the definition of the configuration relationships among producy family modules and the definition of the parameter correlations among producy family modules.The proposed method is used to build the product family used in the rapid design system of the developed product,which is effective to shorten the developing lifecycle of the system. Moreover,the reuse of CAD model on level of assembly is realized.(3) The CAD model retrieval technology is the powerful tool to reuse the CAD model and improve the design effectiveness.To improve the intelligence and the visualization of the CAD model retrieval tool,the CAD model retrieval method based on topology adjacency approximation is proposed on the basis of boundary matching.The method is divided into two steps.Firstly,Breadth-First-Search-based spanning tree algorithm is applied to obtain an initial boundary matching between retrieval object and retrieval condition.Secondly,the topology adjacency approximation algorithm is put forward to find the optimal boundary matching based on the initial boundary matching by the cycle and approximation process,and the matching result is used to calculate the shape similarity between retrieval object and retrieval condition.Finally a CAD model retrieval system on the UG platform is developed based on the proposed method.Experimental results show that the retrieval precision and effectness of the proposed method is higher than other methods,and the adaptiveness and the practicability is better.(4) Aiming at solving the problem on the reuse of heterogeneous CAD model during the process of product rapid design using CAD system,the method of integration data exchange among heterogeneous CAD systems is proposed.The framework of the method is built,and the implementation mechanism is analyzed.The information constitution of CAD model on level of feature is analyzed.The description method of feature information based on feature class is proposed,in which the geometry element identifaction method based on improved geometry certification is presented to name and identify geometry element.The transformation method of design intent information is given,and the design intent information includes design history,feature and constraint.The proposed method has been used in the data exchange between CATIA and UG.Experiments results shows that the sharing, exchange and reuse of CAD model among heterogeneous CAD system can be realized,the loss of design intent is less than other methods,the variant results of target CAD model is same as the source CAD model.(5) The framework of product rapid design system based on the reuse of CAD model is built according to the above-mentioned methodologies,and the function modules of the system are planned.The horizontal condenser is taken as the example to validate the key technologies above-mentioned such as the product rapid design based on product family,the retrieval and reuse of CAD models,the transformation and reuse of heterogeneous CAD model,and the the management and resuse of standard parts model.A rapid design system has been developed for a refrigeration enterprise,and economic benefit was gotten. Finally the research work of this dissertation is summarized,and the innovations are pointed out.Moreover,suggestions for further study are put forward accordingly.更多还原