【作者】 郭四海；

【导师】 冯珊；

【作者基本信息】 华中科技大学 ， 系统工程， 2004， 硕士

【摘要】 基于数字仿真的虚拟制造环境下,拟实生产过程的产品样机称虚拟样机(Virtual Prototype, VP)。虚拟样机概念设计对应于现实世界产品设计过程中的概念设计阶段。本文按照概念设计过程建模的功能-行为-结构(Function-Behavior-Structure, FBS)原则,将虚拟样机概念设计的任务界定为根据用户对新产品的各项需求信息,在数字世界中构建该新产品技术方案的过程;该方案应给出产品提供的功能、它在运行中的行为表现和体现产品功能与行为的载体结构。据此,产品概念设计是基于需求分析的系统集成(综合)过程。本文是作者参与了基于案例推理(CBR)方法的虚拟样机概念设计支持系统的研究与开发实践的总结。首先,在论述CBR方法原理、系统实现中的信息处理流程及相关技术基础上,推出一种基于案例推理的复杂产品虚拟样机概念设计流程框架。在此框架中,产品信息建模即产品的案例形式化描述,及相应案例库的建立与管理是整个系统开发的基础。其中案例的形式化设计又是系统效能成功运用的关键因素。其次,基于产品案例,依据设计任务知识及相关的前提和判断,通过一定推理策略的执行,最终可获得关于新产品的功能-行为-结构方案,从而完成概念设计任务。虚拟样机概念设计支持系统的作用在于辅助用户完成概念设计流程并提高概念设计功效。作者在基于XML的案例描述和结合应用背景的CBR具体技术实现方面进行了具有创新意义的工作。第一,为满足多学科复杂产品虚拟样机通用性要求和适应多用户协同设计工作方式,采用了案例标记语言(Case-based Markup Language,CBML)作为分布式的环境下有效地描述案例的XML衍生式特定标记语言工具。为此作者对CBML语言进行了详细的探讨,针对导弹产品描述的复杂性,解决了有效运用CBML建立导弹产品案例和案例库的工作,并通过系统测试。第二,在案例推理方法方面,基于CBR传统4Re流程模型,分别对案例检索、重用、调整和维护各子流程在概念设计问题求解中的特殊作用,进行适用关键技术的选择、优化与确定。最后集成各子流程功能组件,建成复杂产品虚拟样机概念设计支持系统原型。该原型系统已通过验收。更多还原

【Abstract】 In digital simulation based virtual manufactural environment, product prototype simulating real manufacture process is called Virtual Prototype. Virtual prototype conceptual design corresponds to conceptual designing stage of actual product designing procedure. With Function-Behavior-Structure(FBS) modeling principle of conceptual designing stage, the thesis specified that virtual prototype conceptual designing task, as according to user’s requirements information of the new product, to produce its technological schema for production. The schema should describe product function offered, behavior representation and the substancial carrier structure embodying product function and behavior. Hereby, product conceptual designing is actually a system integration process based on requirements analysis.The thesis summarizes studying and development experiences in activities of constructing virtual prototype conceptual design support system based on CBR. First of all, with a detailed discussion of CBR principle, information flow processing and relevant techniques, the framework of conceptual design for complex products virtual prototype based on CBR is proposed. In this framework, basis of the system is case formalization and case base building . The case formalization design is the key element to improving system efficiency and effectivity. Secondly, according to designing task related preconditions and judgements, FBS schema of new product will be figured out through performing corresponding case-based reasoning strategy, consequently the conceptual design task will then be fulfilled.The effect of virtual prototype conceptual design support system includes aiding conceptual designing flow and effectively improving conceptual design capacity. Author has fulfilled innovation work in integrate case representation base on XML with CBR. Firstly, in order to meet universal demand for multi-knowledge complex virtual prototype and to be adaptive with the multi-user cooperative designing pattern, case-based markup language (CBML) is used as a specific markup language tool derived from XML to efficiently represent case in a distributed working environment. Thus, author introduces CBML in applications, and efficiently builds missile case database aimed at solving complex problem of missile product representation. Secondly, based on CBR traditional 4Re flow model, technical innovation choice and optimization on case representation, case reuse, case adaptation and case maintenance were given in the dissertation. The prototype has been put in use and evaluated with a satisfied record .更多还原