节点文献
机械产品设计知识管理系统的研究
Research on Design Knowledge Management System for Mechanical Products
【作者】 张善辉;
【作者基本信息】 山东大学 , 机械制造及其自动化, 2008, 博士
【摘要】 为了达到以最快的速度、最低的成本提供质量最优的产品来快速响应市场,企业的产品设计逐步表现出快速化、模块化和知识化的发展趋势。这就要求设计人员必须了解产品设计的详细过程和步骤,能在最短的时间内获取有用的产品设计知识。因此,本文结合设计知识多样性、动态性和相关性的特点,重点从设计知识的表示、设计过程的建模和设计过程的规划三个角度对设计知识管理进行了研究,进而达到将正确的知识在正确的时间传递给正确的人的目的,逐步积累企业设计知识,推动企业模块化、快速化设计模式的发展。从知识多源性、人员相关性、过程相关性和异构性角度出发,将设计知识分为描述性知识、判断性知识、结构性知识、过程性知识、方法性知识和手册性知识六类;通过分析设计本体的重点和难点,提出了设计本体的建立方法。在此基础上,以企业的设计过程、设计组织、设计对象和知识对象为核心,分析各部分主要概念的内涵及其属性关系,建立了相应的本体主模型,实现了设计过程、设计组织、设计对象与知识对象之间的关联及六类知识的表示,为后续的知识嵌入和重用奠定了基础。为了响应快速化、模块化、知识化的产品设计发展趋势,结合产品设计的参数化和重复性特征,选择以工作流方法作为设计过程建模的参考技术,提出了基于工作流扩展的设计向导元模型。为了实现设计知识在产品设计过程中的驱动作用,在基于本体的设计知识表示的基础上,构建了支持知识嵌入的知识流引擎,保证了设计过程中的知识嵌入。借鉴IBM FlowMark工作流模型,提出了设计向导的过程模型,并建立了模块任务、零件任务、抽象任务和行为任务四种任务模型,达到了跟踪设计人员的详细设计任务的目的,并为后续的设计过程规划提供了过程模型和信息依赖关系。提出了基于BOM的分层设计结构矩阵(Design Structure Matrix,DSM),并建立了布尔设计结构矩阵(Binary Design Structure Matrix,BDSM)和数值设计结构矩阵(Numerical Design Structure Matrix,NDSM)相结合的产品设计过程规划方法,既保证了规划的效率,又提高了规划精度。在规划过程中,采用了任务次序指标和信息次序指标相结合的耦合任务集的改进割裂方法,使得设计迭代和反复的次数最少。通过对全耦合、部分耦合和多个任务之间的闭环三种耦合形式的分析,针对合并、分解和两种方式相结合的三种解耦途径,借助分层DSM之间的信息交流与遍历,提出了基于耦合度与任务规模约束的解耦策略,并对耦合度及任务规模的度量进行了定义。此种方法可以助力于企业的产品结构、设计团队、设计过程的重组和模块化发展,达到加强设计知识管理的目的。根据上述关键技术的研究,建立了产品设计知识管理系统的总体框架,构建了以知识分类图、知识分布图、知识利用图和知识传递图为组成的知识地图,并进一步分解和明确了各部分的相应职能,为产品设计知识的各类检索和获取提供了可视化的工具。为了将产品生命周期的相关信息应用于设计过程之中并转化为企业的知识,形成各类设计人员所需要的知识视图,提出了以产品生命周期管理(Product Lifecycle Management,PLM)系统的信息为基础的集成框架和以设计知识管理系统的本体为主体的本体映射模型,并研究了以词汇相似度和概念相似度为主要组成的本体映射算法,实现了信息从PLM系统向设计知识管理系统的准确移植。最后,提出了设计知识管理系统(Design Knowledge Management System,DKMS)的设计思想和功能结构,开发了相应的原型系统,并对系统进行了应用验证。
【Abstract】 In order to provide products of best quality for market with the fastest speed and lowest cost, product design gradually shows the trend of high speed, modularization and knowledge coverage. It is required to know the detailed processes of product design and obtain useful knowledge of product design in the possible shortest time. Therefore, in this paper, from the development trend of product design, considering the diversity, dynamic and relativity characteristics of design knowledge, design knowledge management is researched focusing on the representation of design knowledge, modeling and planning of design process, thereby the purpose of giving the right knowledge to the right person at the right time is achieved. It can speed up product design, accumulate design knowledge, and encourage the development of modular design.From the view of multi-derived, personnel-related, process-related and heterogeneous properties of design knowledge, design knowledge is divided into six kinds, such as descriptive knowledge, judgment knowledge, structural knowledge, process knowledge, methodological knowledge and manual knowledge. Analyzing the keystones and difficulties of design Ontology, the establishment method of design Ontology is presented. On this basis, taking design processes, design organizations, design objects and knowledge objects as the hard core of Ontology, extracting the main concepts and properties from every parts, the corresponding Ontology models are formed. They can help to associate design processes, design organizations, design objects and knowledge objects together, realize the representation of six kinds of knowledge, and lay the foundation for the following knowledge embedding and reuse.Responding to the development trends of product design, with the characteristics of parametrization and repeatability for product design, the workflow method is selected as a reference technology for design process modeling, and a meta-model of design guide is presented based on the extended workflow model. In order to achieve the driving function of design knowledge in product design process, based on the design knowledge representation using Ontology, a knowledge flow engine which supports knowledge embedding is formed, and it is ensured that knowledge can be embedded in design processes. Using workflow model of IBM FlowMark for reference, a process model of design guide is proposed, and four kinds of task models like module task, part task, abstract task and behavior task are established. They can achieve the purpose of tracking how a designer accomplish tasks and how to design products and their parts, and provide process models and relationships of information dependence for the following design process planning.A hierarchical DSM based on BOM is proposed, and the approach of design process planning with the combination of BDSM and NDSM is researched to assure both the efficiency of the planning and the high planning accuracy. In the planning process, we put forward an improved dissevering approach of coupled tasks which contains task sequence norm and information sequence norm, and it can make the quantities of design interactions and loops to be small. With the study of three coupling forms like full coupling, partial coupling and closed-loop of multiple tasks, according to three dissevering approaches of combination, decomposition and integration of two ways above, a dissevering strategy based on the restriction of coupling degree and task scale is presented in virtue of information exchange and traversal between hierarchical DSMs, and the measurement of coupling degree and task scale is defined. This method can help to the reconfiguration and modularization of product structures, design teams and design processes, and then the purpose of strengthening the design knowledge management is achieved.Based on the research of key technologies above, an overall framework of design knowledge management system is established, which introduces a knowledge map, sets up knowledge classification map, knowledge distribution map, knowledge utilization map and knowledge transfer map, and decomposes their corresponding functions in detail. It can provide a visualization tool for knowledge search and retrieval. In order to apply related information from product lifecycle in design process, convert them into enterprise knowledge, and form different knowledge maps designers needed, an integration framework based on information of PLM system and an Ontology mapping model taking Ontology of design knowledge management system as mainstay are proposed, and an Ontology mapping algorithm which contains two main parts of glossary similarity and concept similarity is researched. Then, the accurate migration of information from PLM system to design knowledge management system is realized.Finally, the design methods and functions of design knowledge management system are presented, and the prototype system is developed. The feasibility is illustrated through an engineering instance.
【Key words】 design knowledge management; Ontology; design guide; engine of knowledge flow; Design Structure Matrix (DSM); knowledge map;