复杂产品设计的知识建模与重用研究

为了解决复杂产品在设计过程中经验知识重用难的问题,本文划分了四类知识模型与重用方法。为实例类知识模型构建特征向量并建立三级知识检索机制。针对图表类知识采用离散化方法建立表达模型,并分别对存在目标函数与无法建立目标函数两种情况建立知识重用机制。利用输入参数、输出参数形成特征向量,并与数学符号建立公式类设计知识中原子公式的表达模型,利用特征向量匹配实现原子公式的组合重用。采用规律类知识中被影响因素构建特征向量,并利用设计约束触发规律类知识重用。最终满足复杂产品对设计知识表达与重用的要求。     

An ontology-based method for knowledge integration in a collaborative design environment

A collaborative design environment can be viewed as a multi-agent system where each design agent has knowledge about specific domains and can solve different problems. Several agents combine to solve a complex problem through knowledge sharing and inter operation. It is essential to construct an integrated knowledge base to improve the efficiency and consistency of complex problem-solving. An ontology-based knowledge integration framework in a collaborative design environment is presented in this paper. Ontology provides standard vocabulary, technical terminology and a domain model for knowledge integration. The representation and construction of ontology are critic problems for knowledge integration. An object-oriented concept graph representation is presented to represent ontology. It has advantages of both object-oriented methodology and Sowa’s conceptual graph. It can be translated into predicate calculus conveniently, and can represent the intension of concepts. In order to improve the efficiency of ontology construction, a semantic-based approach is presented. Firstly, a semantic affinity based clustering algorithm is presented to generate concepts from the term set of multi-agent systems. Then, ontology is constructed based on knowledge.     

基于知识重用的产品方案设计多级实例推理模型

大型复杂产品方案设计结构配置过程具有复杂性、多层次、多属性和创造性的特点,对设计知识的合理组织和重用是提高产品设计效率的有效保障.在多级设计分解的基础上,研究了大型复杂产品方案设计多级实例推理与重用技术,提出了多级实例推理关联传导过程的形式化表达模型,建立了多级推理过程的传导效应函数,给出了多级实例推理算法和基于多级实例推理初始方案的实现过程.通过实例验证了所提模型与算法的有效性和可操作性.     

Research on ontology-based integration of product knowledge for collaborative manufacturing

One of the most important research subjects germane to knowledge management in collaborative manufacturing is the integration of heterogeneous product knowledge distributed among different collaborative enterprises. To deal with the problem of optimization of knowledge integration in collaborative manufacturing, an ontology-based framework of knowledge integration is presented to transform the problem of knowledge integration into a problem of ontology integration. First of all, a collaborative business process for collaborative enterprises is described, and then an ontology-based framework of knowledge integration is established. Under the condition of analyzing the structure of knowledge ontology, an ontology schema of knowledge concept is discussed. Aiming at the ontology schema, a method of ontology integration based on ontology similarity is improved. The method is composed of ontology mapping and ontology merging, which is based on calculated result of ontology similarity between local ontology and global ontology. Finally, the implementation of the framework of knowledge integration is described, and the application results meet the requirement of the knowledge integration to ensure that validity of the ontology integration method was proved.     

本体在产品知识S-B-F表达模型中的应用研究

设计了基于本体的产品知识结构-行为-功能表达模型。根据本体构建原则和方法,结合语义Web的建模语言OWL,论述了模型中流和行为/功能本体的构建,并以齿轮泵为例进行描述。最后给出了应用分析,证明了本体技术在产品知识建模中的实用性。     

面向知识重用的企业建模框架

针对现有企业建模体系不能支持行业知识表达与知识重用的问题,提出一个面向行业知识重用的多维度企业建模框架。其中,知识层次维由跨行业通用知识层、特定行业知识层、个案企业专项知识层三个子层次组成,用于描述不同抽象层次的知识;知识过程维包括概念化、知识资产获取、重用性设计、知识演化四个子过程,用于知识获取过程控制;知识内容维由一组视图组成,用于对可重用知识及其关系建模。最后,以水泥生产企业为例,说明了该框架在具体企业管理信息化中实现知识重用的情况。     

航天产品设计知识的表示与重用技术研究

航天产品设计需要大量借鉴以往型号产品的设计方案,对设计知识的合理组织和重用是提高航天产品设计效率的有效保障.本文研究了航天产品设计知识表示与重用技术,提出了一种基于实例的设计知识重用方法.通过对航天产品设计过程的深人分析,提出映射体系多级树状结构的知识表示模型,并基于该知识表示模型提出知识检索策略,其中实例检索采取基于相似度的买例检索算法.通过实例检索策略获得符合设计要求的最佳匹配实例及相关设计知识,并以火箭为例进行验证.     

基于知识重用的开关柜设计技术研究

为更好地利用已有的开关柜设计知识提高产品设计效率,分析了开关柜产品的结构特点和设计知识特点,提出了开关柜产品的整机及功能元知识的表达方法,并给出了功能模块的配置规则及范例相似性判别准则.进一步分析了开关柜的配置设计知识的组成及实现配置的方法,采用基于范例推理和配置规则技术,建立了一个开关柜辅助设计系统,并给出了HXGN-12型开关柜设计的应用实例.实例表明,该系统在缩短产品设计时间等方面是有效的.     

支持产品复用的集成产品开发研究

企业在长期的生产活动中积累了大量宝贵的产品资源。如何有效利用这些产品资源是缩短产品开发周期、提高产品质量以及实现对市场的快速响应的关键。将基于实例的推理技术引入产品数据管理,提出一种基于产品数据管理的支持产品复用的集成产品开发环境结构;针对产品属性的特点,提出一种新的实例检索模型,并给出相应算法;为了实现基于实例的设计系统与产品数据管理系统之间的数据交流,开发了两者之间的数据接口;以某钢厂典型产品开卷机为对象,开发了Smar Team环境下的开卷机集成设计系统。该系统能够有效地支持对现有产品资源的复用,缩短开发周期,提高设计质量。研究成果可以推广应用至其他典型产品。     

一种基于特征继承的产品设计重用的方法

从研究各种设计特征的分类入手,运用面向对象的编程思想对简单孔类特征及由其派生出来的沉孔类特征、台阶孔类特征等进行详细的分析,并对这种特征层的设计重用的方法的可行性进行必要的探讨,最后给出一个简单的例子证明这种方法是可行有效的.     

基于知识模板的复杂产品设计重用方法研究

为实现复杂产品设计知识的莺用,提出了基于面向对象技术的知识模板概念.用统一建模语言建立了复杂产品设计阶段的功能-行为-结构模型.通过功能分解和结构映射,将功能信息和向何信息集成封装在一个类模板中.基于功能域、行为域和结构域三个映射域,设计了功能分解算法,从而形成可重用知识.知识模板通过组成模板的静态和动态知识提取并加以综合获得,利用相似度数值的计算进行模板的选择与匹配.最后以叉车产品功能分解和结构映射所形成的知识模板,说明了所提出的设计重用方法的实际应用.     

面向产品设计的多维度知识推送研究

阐述了产品设计知识的多维度概念,提出了基于集对分析的知识多维度筛选模型,给出了需求驱动的产品设计知识服务模型,在产品设计需求的驱动下,对知识进行筛选和排序,提高了知识获取的准确性。通过应用案例,验证了所提方法的有效性。     

An online Web-based environment for detailed design reuse

This research presents an online Web-based environment for the reuse of detailed design. In this environment, users can browse existing product databases including all related product information and graphic displays of the geometrical models, search and retrieve related products and generate new designs from existing products. In the underlying database, product data are clustered into product families to facilitate data management and reuse, and the variant method is adopted to transform an existing design into a new design.     

产品设计中基于元模型的知识管理

为了一致地描述产品设计过程中的多种知识,便于系统实施,提出了基于元模型的知识建模方法.采用面向对象技术,定义信息对象和知识对象,描述对象的特征属性、关系属性和操作.信息对象通过抽取项目管理信息和产品设计信息的特征得到,反映信息实体之间的关系,而知识对象则是通过关联相关信息对象得到.通过对象之间的关系定义可以构建知识地图,实现了对显性知识的导航和对隐性知识的积累.提出了面向产品设计流程的信息获取方法,随着项目的进行,不断丰富信息对象和知识对象.最后,讨论了该方法在ProNet项目中的应用.     

一种面向构件重用的产品构件库设计

在可重构设计系统中,构件资源库是不可缺少的部分,它的丰富程度决定了整个重构设计系统的重构能力和产品范围,它的有效程度决定了产品开发的质量和速度.提出一种面向重构设计应用的,采用层次化存储(功能分解层,功构映射层,构件类关系层和构件明细层),支持多视图检索的构件库技术.应用表明该方法是一种有效的构件库构造途径,此外,它有助于从构造数据库角度来支持产品重构设计并提高后期构件选择的效率.     

大型水轮机方案设计知识重用可拓策略

为继承与重用大型水轮机产品设计知识,通过基元对设计知识进行了描述,研究了产品方案设计知识重用可拓策略,运用基元的可拓性实现了设计知识的拓展,形成了产晶方案设计知识的可拓基元集合,并建立了相应的产品方案设计知识重用可拓模型.最后,以大型水轮机选型方案设计为例,验证了该模型的有效性和可操作性.     

基于本体的复杂产品设计知识优化集成

为解决复杂产品设计知识集成中知识冗余高、集成结果不够优化的问题,提出了一种基于设计知识本体的知识集成器,将这一问题转化为局域本体与全局本体问的本体集成问题.分析了协同设计知识的组成,构建了设计知识本体模型.在此基础上,设计了以本体构建、本体映射和本体合成三个模块为主干的知识集成器,并对本体映射中的相似度给出了量化的评定方法,实现了本体集成.通过应用实例验证了该方法的有效性.     

Challenges of manufacturability and product data management in bending

Effective production in a networking environment of sheet metal products needs accurate and relevant PDM (product data management) data, appropriate modeling of components supported by local and global network solutions, and utilization of advantages of feature-based modeling. To enable these aspects of effective production in sheet metal production, it is necessary to evaluate the integration of DFMA (design for manufacturing and assembly) and PDM. This paper aims at identifying the challenges of DFMA and PDM integration through recognizing possible malfunctioning parts of their integration. The observations are based on sheet metal specimens in which the DFMA and PDM aspects are visible in punching and bending. This study will focus on five issues that are included either in DFMA or PDM, or both: the effects of different calculation methods for the flattened length, utilization viewpoints of global or local manufacturability guidelines, assembly conditions, options to tune the manufacturing process instead of changing the product geometry, and possible additional requirements given by the customers. Based on practical design and manufacturing tests, it has become evident that one option to improve the quality of analyzed sheet metal parts is to further develop the integration of DFMA features with the workshop’s cutting and punching parameters. As one possible improvement to these kinds of integration tasks of DFMA and PDM, it is suggested that the responsibilities for developing DMFA and PDM applications with proper design parameters could be analyzed more deeply between persons working with information exchange, product design, software design, or production machine design.