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1、毕业设计/论文外 文 文 献 翻 译院 系 专 业 班 级 姓 名 原 文 出 处 评 分 指 导 教 师 2012 年3 月3 日毕业设计/论文外文文献翻译要求:1外文文献翻译的内容应与毕业设计/论文课题相关。2外文文献翻译的字数:非英语专业学生应完成与毕业设计/论文课题内容相关的不少于2000汉字的外文文献翻译任务(其中,汉语言文学专业、艺术类专业不作要求),英语专业学生应完成不少于2000汉字的二外文献翻译任务。格式按华中科技大学武昌分校本科毕业设计/论文撰写规范的要求撰写。3外文文献翻译附于开题报告之后:第一部分为译文,第二部分为外文文献原文,译文与原文均需单独编制页码(底端居中)并注
2、明出处。本附件为封面,封面上不得出现页码。4外文文献翻译原文由指导教师指定,同一指导教师指导的学生不得选用相同的外文原文。 机械产品方案的现代设计方法及发展趋势摘要:根据目前国内外设计学者进行机械产品设计时的主要思维特点,将产品方案的设计方法概括为系统化、结构模块化、基于产品特征知识和智能四种类型。指出四种方法的特点及其相互间的有机联系,提出产品方案设计计算机实现的努力方向。关键词:机械产品;方案设计方法;发展趋势引言随着科学技术的飞速发展,产品功能要求的日益增多,复杂性增加,寿命期缩短,更新换代速度加快。然而,产品的设计,尤其是机械产品方案的设计手段,则显得力不从心,跟不上时代发展的需要。目
3、前,计算机辅助产品的设计绘图、设计计算、加工制造、生产规划已得到了比较广泛和深入的研究,并初见成效,而产品开发初期方案的计算机辅助设计却远远不能满足设计的需要。为此,作者在阅读了大量文献的基础上,概括总结了国内外设计学者进行方案设计时采用的方法,并讨论了各种方法之间的有机联系和机械产品方案设计实现的发展趋势。根据目前国内外设计学者进行机械产品方案设计所用方法的主要特征,可以把现代设计方法概括为以下四种:1、系统化设计方法系统化设计方法的主要特点是:将设计看成由若干个设计要素组成的一个系统,每个设计要素具有独立性,各个要素间存在着有机的联系,并具有层次性,所有的设计要素结合即可实现设计系统所需完
4、成的任务。系统化设计思想于70年代由德国学者Pahl和Beitz教授提出,他们以系统理论为基础,制订了设计的一般模式,倡导设计工作应具备条理性。德国工程师协会在这一设计思想的基础上,制订出标准VDI2221“技术系统和产品的开发设计方法。制定的机械产品方案设计进程模式,基本上沿用了德国标准VDI2221的设计方式。除此之外,我国许多设计学者在进行产品方案设计时还借鉴和引用了其他发达国家的系统化设计思想,其中具有代表性的是:(1)将用户需求作为产品功能特征构思、结构设计和零件设计、工艺规划、作业控制等的基础,从产品开发的宏观过程出发,利用质量功能布置方法,系统地将用户需求信息合理而有效地转换为产
5、品开发各阶段的技术目标和作业控制规程的方法。(2)将产品看作有机体层次上的生命系统,并借助于生命系统理论,把产品的设计过程划分成功能需求层次、实现功能要求的概念层次和产品的具体设计层次。同时采用了生命系统图符抽象地表达产品的功能要求,形成产品功能系统结构。(3)将机械设计中系统科学的应用归纳为两个基本问题:一是把要设计的产品作为一个系统处理,最佳地确定其组成部分(单元)及其相互关系;二是将产品设计过程看成一个系统,根据设计目标,正确、合理地确定设计中各个方面的工作和各个不同的设计阶段。由于每个设计者研究HYPERLINK 问题的角度以及考虑问题的侧重点不同,进行方案设计时采用的具体研究方法亦存
6、在差异。下面介绍一些具有代表性的系统化设计方法。1.1图形建模法研制的“设计分析和引导系统”KALEIT,用层次清楚的图形描述出产品的功能结构及其相关的抽象信息,实现了系统结构、功能关系的图形化建模,以及功能层之间的联接 。将设计划分成辅助方法和信息交换两个方面,利用Nijssen信息分析方法可以采用图形符号、具有内容丰富的语义模型结构、可以描述集成条件、可以划分约束类型、可以实现关系间的任意结合等特点,将设计方法解与信息技术进行集成,实现了设计过程中不同抽象层间信息关系的图形化建模。文献11将语义设计网作为设计工具,在其开发的活性语义设计网ASK中,采用结点和线条组成的网络描述设计,结点表示
7、元件化的单元(如设计任务、功能、构件或加工设备等),线条用以调整和定义结点间不同的语义关系,由此为设计过程中的所有活动和结果预先建立模型,使早期设计要求的定义到每一个结构的具体描述均可由关系间的定义表达,实现了计算机辅助设计过程由抽象到具体的飞跃。1.2键合图法系统元件的功能分成产生能量、消耗能量、转变能量形式、传递能量等各种类型,并借用键合图表达元件的功能解,希望将基于功能的模型与键合图结合,实现功能结构的自动生成和功能结构与键合图之间的自动转换,寻求由键合图产生多个设计方案的方 法。2、结构模块化设计方法从规划产品的角度提出:定义设计任务时以功能化的产品结构为基础,引用已有的产品解(如通用
8、零件部件等)描述设计任务,即分解任务时就考虑每个分任务是否存在对应的产品解,这样,能够在产品规划阶段就消除设计任务中可能存在的矛盾,早期预测生产能力、费用,以及开发设计过程中计划的可调整性,由此提高设计效率和设计的可靠性,同时也降低新产品的成本。Feldmann把设计任务的功能化产品结构分为四层,(1)产品(2)功能组成(3)主要功能组件(4)功能元件。采用面向应用的结构化特征目录,对功能元件进行更为具体的定性和定量描述。同时研制出适合于产品开发早期和设计初期使用的工具软件STRAT。认为专用机械中多数功能可以采用已有的产品解,而具有新型解的专用功能只是少数,因此,在专用机械设计中采用功能化的
9、产品结构,对于评价专用机械的设计、制造风 险十分有利。根据机械零部件的联接特征,将其归纳成四种类型:1) 元件间直接定位,并具 有自调整性的部件;2) 结构上具有共性的组合件;3)具有嵌套式结构及嵌套式元件的联接 ;4)具有模块化结构和模块化元件的联接。并采用准符号表示典型元件和元件间的连接规则,由此实现元件间联接的算法化和概念的可视化。3、基于产品特征知识的设计方法基于产品特征知识设计方法的主要特点是:用计算机能够识别的语言描述产品的特征及其设计领域专家的知识和经验,建立相应的知识库及推理机,再利用已存储的领域知识和建立的推理机制实现计算机辅助产品的方案设计。机械系统的方案设计主要是依据产品
10、所具有的特征,以及设计领域专家的知识和经验进行推理和决策,完成机构的型、数综合。欲实现这一阶段的计算机辅助设计,必须研究知识的自动获取、表达、集成、协调、管理和使用。为此,国内外设计学者针对机械系统方案设计知识的自动化处理做了大量的研究工作,采用的方法可归纳为下述几种。3.1编码法根据“运动转换”功能(简称功能元)将机构进行分类,并利用代码描述功能元和机构类别,由此建立起“机构系统方案设计专家系统”知识库。在此基础上,将二元逻辑推理与模糊综合评判原理相结合,建立了该“专家系统”的推理机制,用于四工位专用机床的方案设计中。利用生物进化理论,通过自然选择和有性繁殖使生物体得以演化的原理,在机构方案
11、设计中,运用网络图论方法将机构的结构表达为拓扑图,再通过编码技术,把机构的结构和性能转化为个体染色体的二进制数串,并根据设计要求编制适应值,运用生物进化理论控制繁殖机制,通过选择、交叉、突然变异等手段,淘汰适应值低的不适应个体,以极快的进化过程得到适应性最优的个体,即最符合设计要求的机构方案。3.2设计目录法构造了“功能模块”、“功能元解”和“机构组”三级递进式设计目录,并将这三级递进式设计目录作为机械传动原理方案智能设计系统的知识库和开发设计的辅助工具。4、智能化设计方法智能化设计方法的主要特点是:根据设计方法学理论,借助于三维图形软件、智能化设计软件和虚拟现实技术,以及多媒体、超媒体工具进
12、行产品的开发设计、表达产品的构思、描述 产品的结构。在利用数学系统理论的同时,考虑了系统工程理论、产品设计技术和系统开发方法学VDI2221,研制出适合于产品设计初期使用的多媒体开发系统软件MUSE4Mechanical products of modern design methodology and the programme trendsSummary: According to the current domestic and international product design, mechanical design scholars of the main features of
13、 thinking, product design methods summarized as a systematic programme, modular structure, based on product knowledge and wisdom of the four types. That the four methods of the organic link between features and its proposed product design computer programmes to achieve endeavors. Keyword: mechanical
14、 products; Programme design; TrendsIntroductionWith The rapid development of science and technology, the functional requirements of a growing number of products and complexity increase, shortened life expectancy, upgrading speed, the design of the products, particularly machinery products programme
15、design are in urgent need .At present, computer-aided product design drawings, design calculations, processing manufacturing, production planning has been a relatively broad and in-depth study, but results and product development programme of the early computer-aided design falls far short of the de
16、sign requirements. To this end, the author read a lot of literature on the basis of summarizing the design scholars and the methods used for programme design, and discussed ways of the organic link between the computer and mechanical products for programme design trends. Under the current design sch
17、olars and mechanical products used in the design of programmes of the main features of methods, the modern design of the programme approach can be summarized as the following four types: 1. Systematic design methodology The main features of a systematic design methodology: design by several design e
18、lements as a system, the independence of each design element, the presence of various elements of the organic link between each element, and is layered, all elements of the design System design can achieve the required tasks. Systematic design concepts in the 1970s by the German scholar, Professor P
19、aul and Baits, their theoretical system based on the general pattern set design, by design, should be rational. German Engineers in the design concepts on the basis of criteria developed VDI2221 technical system design methodology and product development. Mechanical product development programmer de
20、sign process model basically follows German standards VDI2221 design. In addition, many of our scholars in product design and programmer design was cited for the systematic design and other developed countries, including a representative is: (1) The user needs to be functional as a product of concep
21、tion, design and structural components design, process planning, operational control of the foundation, from the macro-product development process starting, the use of qualitative methods of functional layout, systematic information to users needs rational and effective products into all stages of d
22、evelopment objectives and technical control of the operations. (2) See product as the level of product life systems of organisms, and by systems theory to life the product design process can be divided effectively as demand levels, the achievement of the functional requirements of the specific desig
23、n and product concept level. At the same time the use of life chart at abstract expression products functional requirements, and form the architecture of the products system. (3) Mechanical design system science applications into two basic issues: First, the design of products as a system to deal wi
24、th, the best set of its components (modules) and their interrelationship; Second, product design process as a system, according to the design goals, and correctly, reasonably identify the various aspects of the design work and various design stages. Since each of the designers study and consider the
25、 perspective of the different focus, programmer design specific research methods are used to exist. The following are examples of some representative systematic design methods. 1.1 design analysis and guidance systemKaleit with clear graphic description of levels of functional structures and related
26、 products abstract information systems achieved structural, functional relations graphics, modeling, and the functional connectivity between the layers. Will be designed into two complementary methods and the exchange of information, analytical methods used Nissans information can be used graphic sy
27、mbols, a rich semantic model structure, can be described integration conditions, can be divided type, can be achieved in relations between the arbitrary characteristics, design methodology Xie and information technology integration, achieved design process information among different abstract level
28、of relations graphics modeling. Documentation 11 network design will proceed as a design tool in the development of reactive ask semantic network design, the use of nodes and a network of lines to describe design nodes that components of the module (such as design tasks, functions, components or pro
29、cessing equipment), and lines to adjust the definition of nodes between different semantic relations, The design process for all the activities and results of a pre-established models for early design requirements definition to the specific description of each structure can be expressed by the relat
30、ionship between the definition, computer-aided deplaning process to achieve a leap from abstract to concrete. 1.2 Linkage chart law Integral components of the system can be divide into a functional energy, energy consumption, changing energy forms, such as various types of energy transmission, and a
31、 plan to borrow the functional components express their hope that will be based on a functional model and get a map of achieving functional structure of the automatic generation and functional structure with a map button automatic conversion, Kin seek Hop chart produced by the various design options
32、 to law. 2. Structural modular design methodologyPlanning products from the perspective of: definition design tasks to the functional structure of products based products have been quoted solution (such as a spare parts components, etc.) to describe the design task of decomposition mandate to consid
33、er each sub-task existence counterpart solution of products, so that products can be in the planning stage for the elimination of the design tasks that may exist contradictions, Early projections production, costs and the development of the planned revision of the design process, thus increasing des
34、ign efficiency and the reliability of the design, while also reducing the cost of new products. Feldman task to design the functions of the product mix is divided into four, (1) products (2) functional composition (3) The main function of components (4) functional components. Feature-oriented applic
35、ations using structured catalogue of functional components that is more specific qualitative and quantitative description. At the same time developed a design suitable for product development and early software tools used by early Start. Most of the functions that can be used for mechanical products
36、 have been solution, and with only a few new functions solution dedicated, specialized in the mechanical design of a functional product mix, dedicated machinery for the evaluation of the design, manufacture wind-very favorable. According to the connectivity features of mechanical parts will be conso
37、lidated into its four types:1) A direct positioning components, and since there is a readjustment of the components;2) Structure with the combination of common;3) Of a nest and the nest-style structure of the links-style components;4) A modular structure and modular components connectivity. And the
38、use of symbols that prospective typical components and the inter-linking components rules, thus achieving connectivity between the components of the algorithms and concepts visualization.3. The characteristics of knowledge-based products in the design methodology Design methods based on product char
39、acteristics knowledge of the main features: a computer language to describe the identification and design of products features experts in the field of knowledge and experience, knowledge base and establish the corresponding reasoning machine to use the storage areas have knowledge of the reasoning m
40、echanism and the establishment of the programmer to achieve computer-assisted design products. Mechanical systems design of the programmer is based on products of the main features, and design experts in the field of knowledge and experience on the volume and decision-making, complete body type, a f
41、ew integrated. Computer-aided design stage to achieve this, we must study the automatic acquisition of knowledge, expression, integration, coordination, management and use. To this end, and scholars in mechanical systems design knowledge of programmed design automated processing done a lot of resear
42、ch work, the methods used can be summarized in the following few. 3.1 Coding methodAccording to motion transform (called functional element) the organization classified, and use codes to describe the types of institutions and function element, which has led to the establishment of body system progra
43、mmer design expert systems knowledge base. On this basis, binary logic of combining theory with vague integrated judge the establishment of the expert system reasoning mechanisms, and dedicated spaces for the four programmers designed machine tools. Use of biological evolutionary theory, through natural selection and sexual reproduction to enable organisms to the principles of evolution, in programmed design agencies, the use of network theory approach wi
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