面向重用的产品设计过程知识建模与检索

针对传统的产品设计过程知识模型与知识检索方法在提高产品设计过程知识重用性上的不足,提出了多层次多粒度的知识模型以及基于语义的智能检索算法。首先通过分析产品设计过程知识重用的需求,将产品设计过程知识分为项目管理知识、领域知识、产品设计对象知识三类,并建立对应的多层次知识模型。然后在运用本体技术建立产品设计过程知识本体库的基础上,提出了一种基于语义的智能检索算法。最后给出了产品设计过程知识重用模型,并以柴油发动机方案设计为例,证明了该模型的有效性。     

产品知识模型建模方法的研究

研究了基于知识管理的产品设计信息表示、组织和存储方法，采用语义对象表达产品模型，以产品结构树为组织核心，把定义产品的知识资源关联起来，通过产品配置管理，对产品对象、版本及相互之间的关系进行维护，构建了管理和重用设计知识的产品知识模型。基于该产品知识模型可以实现敏捷产品开发，实现企业及企业间产品协作、知识集成与共享。     

有效支持设计知识检索和重用的扩展的设计理性表示

设计理性是对产品设计过程的解释和记录,是一类重要的设计知识,其内容和表示对于有效支持设计知识的检索和重用起着关键作用.针对设计知识检索和重用的需要,提出一种基于本体的扩展的设计理性表示模型.通过分析需要检索和重用的设计知识,给出以IBIS表示为基础,结合FBS模型、产品层次模型和产品需求的设计理性扩展表示;并据此构建设计理性本体以及相关的语义规则,以有效地支持基于语义的设计知识的检索和重用.实验结果表明,文中模型具有良好的表达能力和可用性.     

基于语义的三维CAD模型可重用区域自动提取

针对产品设计中的局部检索重用需求,提出一种基于语义分析的可重用区域自动提取方法。通过采用扩展特征树表征三维CAD模型,准确刻画设计模型中不同粒度、不同形式的特征及特征间的关联关系,有效捕捉模型中包含的设计语义;通过分析局部区域的设计重用性,提出局部区域可重用性度量函数,并以扩展特征树的表征结构为输入,依据局部区域的可重用性自动提取候选可重用区域;通过进一步评价候选可重用区域的重用率确定最终可重用区域,以确保可重用区域的有效性及合理性。实验结果表明,依据本方法提取获得的可重用区域符合设计重用语义,能有效支持产品设计阶段的局部检索重用。     

公理化设计框架下产品设计知识重用的关键技术

针对具有层次性、多属性特点的复杂产品设计过程,对公理化设计框架下的产品设计重用技术进行了研究。通过建立公理化设计框架将复杂产品设计过程进行分解,形成产品设计的需求域、功能域、结构域与工艺域的Z形映射关系,提出一种基于实例的综合考虑设计域间和域内设计信息的知识重用方法,采用基于相似度的知识重用检索算法,获得符合设计要求的最佳重用对象,并以实例进行了验证。     

基于图解特征语义认知的产品设计过程知识模型

针对产品造型设计过程知识表征,提出基于图解语义认知的产品设计过程知识模 型。分析产品的本体语义及产品设计过程知识,结合可拓学基元理论构建产品设计过程的知识 表征基元模型,提出可拓原点基元及可拓向量概念,实现设计过程--设计生长、设计收敛及 设计优化的知识表征。在产品设计过程知识基元表征模型基础上,提出基于图解语义的实例库 聚类方法模型。以机床装备造型设计为例,验证了该方法的可行性,为产品造型设计提供一种 形式化与量化相结合的设计参考方法。     

基于语义对象网络模型的产品知识表达方法

为表达产品知识及其语义内涵和约束关系,提出采用语义对象网络模型（Semantic Object Semantic Networks,SOSNs）表达产品知识。SOSNs是基于图并结合面向对象方法表达的知识模型,其中节点表示产品语义对象,有向边显性定义语义对象之间的语义关系,这种基于图的语义模型能够清晰的表示产品功能、行为、原理、结构、配置管理、约束等知识及其语义关系,将与产品开发相关的知识集成为一个逻辑整体,形成分层的结构化语义对象网络结构,便于组织和管理产品知识,易于实现知识的共享和重用。     

语义驱动的集成化产品建模

针对复杂产品研发过程中多领域协同对产品知识共享和重用的需求,提出一种语义驱动的集成化产品建模方法.结合多本体技术,给出了集成化产品建模框架,该框架由概念层和模型层构成,概念层包括高层核心产品本体和领域本体,模型层由主模型和领域模型等一族模型构成;同时还给出了集成化产品模型的形式化语义描述,在构建高层核心产品本体的基础上建立主模型;基于多领域本体,进行由概念层语义驱动的领域模型快速重构,在语义理解基础上实现跨领域的产品知识重用.     

航天产品装配工艺知识库建模与检索

针对某航天企业装配工艺知识数量巨大而繁杂的特点,梳理该航天产品装配工艺知识,建立装配工艺知识体系。研究基于本体的装配工艺知识建模方法,建立装配工艺知识本体模型,并应用OWL本体形式化语言对装配工艺知识进行本体编码。基于装配工艺知识本体模型,设计装配工艺知识语义相似度算法,该算法综合基于距离的语义相似度和基于属性的语义相似度计算领域本体内部概念间的语义相似度。最后,将所研究的装配工艺知识模型和语义相似度算法应用于某航天产品装配工艺知识库系统,实现了某型号产品的装配工艺知识有序管理和共享重用。     

面向语义信息的案例知识表达与相似度计算方法研究

传统的案例知识表达与共享方式已越来越难以满足目前产品设计对案例知识获取的要求。为了实现异构案例知识的表达与重用,本文面向语义信息提出了一个由概念、表达、特征、类型构成的案例知识本体,旨在对案例知识进行概念化与语义化,并通过概念之间的关系生成概念树,为案例相似性分析提供一个量化方法。为了对案例进行比较、评价和挖掘,探讨了一种基于概念相似度与概念属性相似度的计算方法。另外,结合开发的车门案例知识库说明了模型与方法的可行性和有效性。     

A semantic knowledge management system for laminated composites

The engineering of laminated composite structures is a complex task for design engineers and manufacturers, requiring significant management of manufacturing process and materials information. Ontologies are becoming increasingly commonplace for semantically representing knowledge in a formal manner that facilitates sharing of rich information between people and applications. Moreover, ontologies can support first-order logic and reasoning by rule engines that enhance automation. To support the engineering of laminated composite structures, this work developed a novel Semantic LAminated Composites Knowledge management System (SLACKS) that is based on a suite of ontologies for laminated composites materials and design for manufacturing (DFM) and their integration into a previously developed engineering design framework. By leveraging information from CAD/FEA tools and materials data from online public databases, SLACKS uniquely enables software tools and people to interoperate, to improve communication and automate reasoning during the design process. With SLACKS, this paper shows the power of integrating relevant domains of the product life cycle, such as design, analysis, manufacturing and materials selection through the engineering case study of a wind turbine blade. The integration reveals a usable product-life-cycle knowledge tool that can facilitate efficient knowledge creation, retrieval and reuse from design inception to manufacturing of the product.     

A study on the collaborative management method of product design cycle knowledge

Because of the ever-increasing market competition and rapidly changing of customers’ requirements, the innovation quality and design efficiency of knowledge-intensive product has become the key factors in business success. The traditional knowledge management method which is based on design reuse and the single categories of design knowledge cannot satisfy these demands any more. Therefore, in order to effectively support the innovative design process of enterprises, a design knowledge collaborative management method based on multi-knowledge migration is proposed. According to the characteristics and functions during the product design process, the design knowledge is divided into three categories, design principle knowledge, design domain knowledge and design object knowledge. By extracting the operation attributes, relation attributes and physical attributes of the design knowledge, a unified knowledge representation model is established for different design participants. The ontology concept and knowledge matrix are used to establish the association between various categories of design knowledge. Multifarious knowledge search methods include keyword, function, principle and natural semantics are proposed for different design participants in different design stages. They can not only realize the knowledge reuse in the same domain but also support the cross-domain knowledge migration among different domain. Finally, based on the system analysis modelling, a design knowledge collaborative platform is established for the design process of mechanical products. A case study is also presented to illustrate the implementation of the platform.     

基于哈希的二维工程 CAD 图纸检索技术

针对企业在设计创新过程中大量采用已有计算机辅助设计(CAD)图纸进行设计重 用的情况,提出了一种基于哈希的二维工程 CAD 图纸检索方法。首先基于环形分割算法提取 工程 CAD 图纸中每个组件对象几何特征;基于传统 LBP 算子提出了一种局部拓扑矢量量化模 式(T-LVQP),实现对各个组件拓扑特征的提取;然后基于协方差描述符融合几何特征和拓扑特 征,通过 LBG 算法将所有组件按照几何特征分组后得到工程 CAD 图纸的特征向量表达;最后 通过迭代量化哈希算法生成图纸的哈希序列。实验结果表明,该算法检索速度快、准确度高, 对于二维工程 CAD 图纸具有较好的检索效果。     

基于知识重用的服装CAD系统

针对当前CAD软件对设计知识重用支持不足且大多基于WIMP交互方式等问题,设计并实现一个基于知识重用的服装工艺设计系统。该系统框架主要包括知识推荐和知识编辑2个模块。针对知识推荐和知识编辑,分别提出基于草图相似性的实时知识推荐算法和基于笔手势的知识编辑方法,给出系统的应用实例。该系统已应用于北京某羊绒企业的生产中,实践表明该系统能改善人机交互,提高设计效率。     

基于本体和粗糙集的协同产品设计知识约简

协同产品设计具有知识来源广、知识类型复杂多样等特点。为简化产品设计知识库并从中有效地提取出对产品设计人员有价值的知识,提出了基于本体和粗糙集的协同产品设计知识约简方法。首先通过引入本体技术对设计知识进行本体建模、显式定义语义和统一表达,以增加产品设计知识的语义;然后通过决策属性的正域及核求解等知识约简方法将设计知识库中对设计人员不重要的、冗余的知识进行约简,精练设计知识库,分析并求解出了约简后知识库中知识的依赖度,从而为设计人员选取与设计密切相关的知识提供依据。最后以汽车发动机的协同设计为例介绍了本文的方法。     

Reverse innovative design — an integrated product design methodology

Today’s product designer is being asked to develop high quality, innovative products at an ever increasing pace. To meet this need, an intensive search is underway for advanced design methodologies that facilitate the acquisition of design knowledge and creative ideas for later reuse. Additionally, designers are embracing a wide range of 3D digital design applications, such as 3D digitization, 3D CAD and CAID, reverse engineering (RE), CAE analysis and rapid prototyping (RP). In this paper, we propose a reverse engineering innovative design methodology called Reverse Innovative Design (RID). The RID methodology facilitates design and knowledge reuse by leveraging 3D digital design applications. The core of our RID methodology is the definition and construction of feature-based parametric solid models from scanned data. The solid model is constructed with feature data to allow for design modification and iteration. Such a construction is well suited for downstream analysis and rapid prototyping. In this paper, we will review the commercial availability and technological developments of some relevant 3D digital design applications. We will then introduce three RE modelling strategies: an autosurfacing strategy for organic shapes; a solid modelling strategy with feature recognition and surface fitting for analytical models; and a curve-based modelling strategy for accurate reverse modelling. Freeform shapes are appearing with more frequency in product development. Since their “natural” parameters are hard to define and extract, we propose construction of a feature skeleton based upon industrial or regional standards or by user interaction. Global and local product definition parameters are then linked to the feature skeleton. Design modification is performed by solving a constrained optimization problem. A RID platform has been developed and the main RE strategies and core algorithms have been integrated into SolidWorks as an add-in product called ScanTo3D. We will use this system to demonstrate our RID methodology on a collection of innovative consumer product design examples.     

DEVELOPMENT OF AN INTELLIGENT PRODUCT DESIGN SYSTEM: INTEGRATION STRATEGIES

Conventional computer-aided design (CAD) packages have drastically reduced the workload of the human designer and shortened the product design cycle. However, the degree of effort and volume of information required to use these tools limit their use to the later stages of design. Intelligent computer-aided design (ICAD) systems have sought to provide a more complete design tool to assist the designer in all phases of design. ICAD systems incorporate conventional CAD elements as well as knowledge engineering constructs. The level of integration between different components of an ICAD system determines its usefulness. Most commercial intelligent CAD packages are tied to a specific set of CAD tools, restricting their application domains. This dependence on specific software tools can be reduced by using general purpose modules to interface with available CAD packages. This paper discusses a method of introducing knowledge engineering technology to help develop an advanced intelligent product design system by integrating ICAD's Concept Modeller with SDRC's l-DEAS package for engineering product design. This integration is necessary because neither the Concept Modeller nor the I-DEAS package provides any unified design environment where users can access both symbolic and numerical design tools as needed to carry out design synthesis and analysis activities. Interfacing engineering design and knowledge processing together is not an easy task. The task is further complicated since it needs to be done only by those who have enough knowledge of both technologies, and also because it may result in reorganization of the traditional design process altogether. The proposed intelligent product design system uses artificial intelligence techniques to take care of human experts knowledge and it advocates the use of several commercial software packages that come from a variety of sources (and are proven to be robust) to perform design synthesis in a cost-efficient and timely manner. The technique described here is relatively easy to implement and is well suited to industrial needs.