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1、个人资料整理仅限学习使用毕业设计 (论文 外文资料翻译设计题目: 取力箱箱体工艺及装备设计译文题目 :组合机床设计的模块化建模方法附件 1：外文资料翻译译文组合机床设计的模块化建模方法图尔加埃萨尔美国密歇根大学研究生研究助理机械工程系安阿伯Ann Arbor tersal umich.edu 杰弗里 L斯坦美国密歇根大学机械工程学系教授Ann Arbor stein umich.edu 卢卡斯卢卡塞浦路斯大学机械与制造工程讲师部lsloucaucy.ac.cy 精选学习资料 - - - - - - - - - 名师归纳总结 - - - - - - -第 1 页，共 24 页个人资料整理仅限学习
2、使用摘要在市场需求讯息万变的情况下，为提升工业竞争力，称为组合机床RMTs ）的新一代机床应运而生。为这些机床的高效设计，则须提出新的方法和工具。这是本文提出组合机床伺服轴模块化建模方法的目的，而这也只是努力发展集成的组合机床设计和控制环境的一部分。该机床的组件被模块化，这样就可以将相应的组件基于机床拓扑学装配起来得到任何特定的配置模型。组件模型使用内置的图形代码以促进所需模块库的直接发展。这些机床模块可用于评估，设计和机床伺服轴的控制。这种方法已有实践证明，人们对其优缺也有一定认识。结果表明，该方法是实现自动化和集成的机床设计环境很有希望的一步。人们对完成这个目标所要面对的挑战也进行了探讨。
3、引言不断增长的竞争迫使制造商更快速地响应需求的变化。因此，制造商必须面对产品市场周期短，过渡时期短，型号和量变化频繁的情形，而且不能影响产品质量和成本。作为制造系统的核心，改进的机床在满足上面提到的需求上把握着关键技术。传统的机床在专用和柔性上的缺点今更胜昔：因其设计的重点在单一部件，使专用设备缺乏柔性机床所具备的灵活性和可扩展性。另一方面，柔性机床无法实现鲁棒性，高的成本效益和专用设备所有的生产量水平。新一代机床在美国密歇根大学工程技术研究中心由Ann Arbor精选学习资料 - - - - - - - - - 名师归纳总结 - - - - - - -第 2 页，共 24 页个人资料整理仅限
4、学习使用主持开发，为的是克服现有生产系统的不足部分为可重构制造系统而开发。这些机床称为组合机床RMTs ）2 ，它们结合了专业和灵活的优点。它们围绕一个零件族和他们的结构设计，在硬件和软件方面，可以快速的改变，经济有效地实现精确的功能和满足设备需求 3 。含多种配置，提供所需柔性和可扩展性，RMTs本质上导致了更复杂的机床设计问题。帮助促进RMTs设计的方法和工具将很大的促进可重构制造系统的应用4-6 。RMTs设计问题的一个重要方面是发展动态模型的设计，伺服轴的控制和赋值。使RMTs建模问题独特的是，即使仅有一台机床，也和存在几种不同的配置，且单独的模式，必须开发。为所有可能的配置开发动态模
5、型可能是一个繁琐和费时的任务，即使利用了特别的方法。而且，没有系统的方法建模将需要大量的专业知识，并容易出错，从而降低了设计中使用模型的效率。本文提出了一种方法，可以有助于减少RMTs 建模的时间，出错和麻烦。这一方法的核心思想是利用RMTs的模块化结构的优势，采取 RMTs 模块化建模方法的建模概念。首先，RMTs的物理组件的模块化建模方式是使用键合图建模工具7 。该键合图模型被封装在一个定义的连接端口的示意图中。然后，原理组件模型按照给定的配置拓扑来组装获取配置模型。配置模型很容易与非动部件如插补器和控制器结合，这可用条形图方便体现；但是这超出了本文的范围。精选学习资料 - - - - -
6、 - - - - 名师归纳总结 - - - - - - -第 3 页，共 24 页个人资料整理仅限学习使用背景RMTs概念是由科伦和哥打 2 提出，从那时起， RMTs的设计就是一个活跃的研究领域。设计RMTs4的方法、工具以及评价结构刚度5 和提示错误 6 设计的替代工具已经开发出来。然而，开发一个系统级建模方法的问题还没有解决。传统上，机床模型描绘伺服电机和驱动装置为第一或第二阶系统8,9 。然而，陈和特卢斯季认为一旦采用了高速机床伺服驱动的结构动力可能会影响系统性能 10 。许多研究人员认定需要配合结构动力学在高速机床上使用高阶模型，以便能够成功设计其控制系统11-13 。这些论述清楚地
7、表明，机床建模不是一项简单的任务和考虑复杂模型时必须要细心，但他们没有提供系统的建模方法，因此，仍然得应用特殊方法。为有助于设计和控制机床伺服驱动，仍有人努力做自动仿真模型的研究。威尔逊和斯坦开发了一个叫建模助手的软件程序能在一个给定的影响范围内自动创成机床驱动系统微型模型FROI ）14 。该模型包括飞轮、一个扭转轴、一滚珠丝杠、一滚珠直流电动机、一个扭转连接键、带驱动和齿轮副的组成部分，其复杂性自动增加，直至超过规定FROI的特征值。这项工作仅是一个概念模型推演法则的证明，不能适用于任何真正的机床系统。不过，这种方法可以用来确定发展系统模型时其复杂性是否适当。戈蒂埃等已经开发出一种名为SI
8、COMAT 的软件包 仿真与控制的机床分析），这有助于建模，仿真，模态分析和控制器的一倍或两精选学习资料 - - - - - - - - - 名师归纳总结 - - - - - - -第 4 页，共 24 页个人资料整理仅限学习使用倍减震或两个机床轴耦合15 。他们的模型由大量的模块和弹簧描述机械系统的动态特性。这项工作使得机床的建模过程更加系统，因此对建模工程师来讲是很有价值的工具，但它缺乏RMTs设计方式所要求的普遍性、模块性和柔性。RMTs建模方法如图1 显示了所设想的 RMTs建模环境。这对于实现RMTs建模任务自动化是理想的，而特定的 RMTs的配置模型自动从标准组件模块库组装。这样所
9、有人工或自动产生的候选设计都可以快速模拟，而其模型可用于就它们的伺服轴动态性能和帮助设计方面评价候选方案，如图一所示，模块化组件模型库是一个自动的RMT建模环境的重要组成部分。因此，拟议方式的第一步就是为了开发用于生成RMT配置组件的标准模型。本文将重点放在机械零件上，并讨论了它们模块化的建模方法。因为机械部件之间相互影响，促成它们的模块化。更有趣的造型。只交流如插补器和控制器信号的模块化建模的组件，提出了一种比较简单的问题，这儿不再讨论。为促进模块化和使组件与环境之间的能量交流更容易，键合图被作为了建模语言。键合图提供电力的物理系统的图形表示。此外，键合图用统一的方式描述了不同的能源领域，这
10、对RMTs建模是相应的优势，因为他们的伺服轴可能包括来自不同领域如机械、电气或液压的组件。键合图只是用在这项工作中模型体现分级结构中的一级。键合图下一水平的数学方程式代表键合图体现的物理现象，这种数学体现只是层次结构中的最低水平。最高级别的键合图都被封装在一个示意图中，这不仅表现紧凑，而且还显示与环境融合的连接端口。图2精选学习资料 - - - - - - - - - 名师归纳总结 - - - - - - -第 5 页，共 24 页个人资料整理仅限学习使用说明了这种层次模式体现。这篇论文所有的模型显示在原理层次，因为本文的目的不是讨论他们的来历，而是想一旦得到这些模型能够做些什么。本文所用模型
11、的详细描述在16 中都可以找到。为了能够应付任何经历不同配置的机械部件的空间运动，使用了捕捉三维动态的模型。此外，最初的假设是，在机械领域范围内所有组成部分都可作为刚体充分体现。图 3 所示的有 N 连接端口的一般刚体是模块库中的一个主要模块。对应于刚体上兴趣点的端口，与环境发生物理上的交互。关系用于指示端口是原子端口，如主要部分能通过端口与所处环境交换能量。而现行的关系则指出了信号端口。只有信息通过这些端口传输。模型库还包含三维连接模块可用于描述构件模型的相关运动。这些联合模块和端口也以标准开发，这样他们可以连接到其他模型模块。该库提供了两种方法来表达制约因素：1）硬的弹簧和减震器可以用来实
12、现更现实的限制，或近似理想的限制；2）拉格朗日乘数可以引进来表达理想约束。对于联合模块的论述读者也被称为16 。一旦模型库由一些基本的模块化刚体和模型组建，建模过程可以进行如下： RMT构件被分解成单件，每个单件与库中的模型相关。如果库中的模型模块都不能完全描述这个单件，那么必须开发一个新的相关模块并添加到库中。然后，模型根据构件拓扑并使用必要的结合块组装。一旦获得组件模型，它可以存储在库中备用。最后，组件模型按照给定的配置拓扑获得该配置模型的组装。这个精选学习资料 - - - - - - - - - 名师归纳总结 - - - - - - -第 6 页，共 24 页个人资料整理仅限学习使用过程
13、可以用图 4 的流程图及以下部分的例子给予证明。实例下面两个例子给提议的建模方法一个概述。第一个例子显示了一个幻灯片建模和第二个例子采用该幻灯片模式发展为RMTs模式。这些例子的目的是提供一个关于组件的模块化如何用在建模流程中的总体思路，而不是解释每个子）组件如何识别和建模的详细信息。因此，该模型模块的细节如它们的复杂程度都没有讨论。滑动体建模是大多数机床工具基本组成部分，包括RMTs 。不同的 RMTs配置可以通过添加 / 删除滑动体获得或重新配置现有结构中的滑动体。因此演示一个滑动体建模流程是有益的。参看图5 所示的滑动体。这是假设的构成部分即如图所示。本示例的目的，所有除电机外的子构件可
14、以像刚体与各连接点样建模。电动机的动力可分为两个用途：三维架构刚体动力和驱动转子和定子之间旋转运动的机电动力。电动机获取双领域动力的模型也已经开发出来，其示意图由图 6 给出。弓形 RMT的模型是由美国国家科学基金会工程研究中心可重构制造系统在密歇根大学开发的，是世界上第一个完整规模的RMTs 。这是一个3 轴机床，其设计围绕着具有五个不同表面族，这些表面倾角变化范围从 -15 至45 ，一次增量15 。它还具有如磨削、钻削加工任意角度的柔性。弓形RMT的可重构性来自于主轴单元，它可通过弓形模块的弯曲导向槽移动从而在上面提到的5 个角度得到配置，然后在任意一个位子上由机械挡块固定。为了举例假精
15、选学习资料 - - - - - - - - - 名师归纳总结 - - - - - - -第 7 页，共 24 页个人资料整理仅限学习使用设基本模块是完全相同的，并对机床没有动力的影响。该工作台、圆柱、主轴基本上都是滑动体，其模型都以上述滑动体模型为基础。该拱被建模为刚体并带有与每个机械挡块连接的端口。最后，该拱式RMT模型按实际机器的拓扑结构组装。要注意这个数字显示的模型只是配置之一。其他配置的模型可通过改变拱模型连接端口得到。既然模型已组装，运动方程可以自动从图形模式得出，并执行仿真。尽管数学模型准备好了，由于当前缺乏好的系统参数估计，我们不能在本文中提供任何仿真结果。一旦参数值可用仿真就很
16、容易进行。讨论本文中标准建模和分级建模概念被确定为RMTs建模方法的主要特点。 RMTs的模块化结构使这种建模方法很有益处，因为这些模型包含了所有可重构的重要特征17 ：1模块化： 子）组件建模模块化2可集成：该模块可以通过其连接端口与其他模块集成3定制：详细程度包括了模型模块都可为单个组件进行定制4可重构性：模型可以很容易地从一个配置转换到另一个5诊断性：可方便地进行模块的模型验证本文介绍的方法可以将建模任务分为两个步骤：1）开发组件模型；, Genoa, Italy, October 28-3117 Koren, Y., Heisel, U., Jovane, F., Moriwaki,
17、T., Pritschow,G., Ulsoy, A. G., Van Brussel, H., 1999, “Reconfigurable Manufacturing Systems”,Annals of the CIRP, Vol. 48/2, pp.527-540附件 2：外文原文A MODULAR MODELING APPROACH FOR THE DESIGN OFRECONFIGURABLEMACHINE TOOLSTulga Ersal Graduate Student Research AssistantDepartment of MechanicalEngineeringUn
18、iversity of Michigan, Ann Arbortersalumich.eduJeffrey L. Stein ProfessorDepartment of Mechanical EngineeringUniversity of Michigan, Ann Arborsteinumich.eduLoucas S. Louca LecturerDepartment of Mechanical and ManufacturingEngineeringUniversity of Cypruslsloucaucy.ac.cyABSTRACT A new generation of mac
19、hine tools called Reconfigurable Machine Tools (RMTs is emerging as a means for industry to be more competitive in a market that experiences frequent changes in demand. New methodologies and tools 精选学习资料 - - - - - - - - - 名师归纳总结 - - - - - - -第 13 页，共 24 页个人资料整理仅限学习使用arenecessary for the efficient de
20、sign of these machine tools. It isthe purpose of this paper to present a modular approach forRMT servo axis modeling, which is part of a larger effort to develop an integrated RMT design and control environment. The components of the machine tool are modeled in a modularway, such that the model of a
21、ny given configuration can beobtained by assembling the corresponding component models together based on the topology of the machine. The component models are built using the bond graph language that enables thestraightforward development of the required modular library.These machine tool models can
22、 be used for the evaluation,design and control of the RMT servo axes. The approach is demonstrated through examples, and the benefits anddrawbacks of this approach are discussed. The results show that the proposed approach is a promising step towards anautomated and integrated RMT design environment
23、, and thechallenges in order to complete this goal are discussed. INTRODUCTION The ever-growing competition forces manufacturers to respond more quickly to changes in demand. As a result, manufacturers have to deal with short product life cycles, short ramp-up times and frequent changes in product m
24、ix andvolumes, without compromising product quality and cost.Being the heart of a manufacturing system, improvedmachine toolshold the key in meeting the above mentionedrequirements. Theshortcomings of conventional machine tools,which can be classified as dedicated and flexible, are being feltmore to
25、day than in the past: With their design focus being asingle part, dedicated machines lack the flexibility and scalability that the flexible machines offer. On the other hand, flexible machines cannot achieve the robustness, the cost-effectiveness and thethroughput levels of dedicated machines1. A ne
26、w generation of machine tools is being developed in theEngineeringResearch Center for Reconfigurable Manufacturing Systems at the University of Michigan, Ann Arbor, as part of an effort to overcome the insufficiencies ofcurrent manufacturingsystems. These machine tools are calledReconfigurable Machi
27、ne Tools(RMTs 2, and they combinethe advantages of their dedicated and flexible counterparts.They are designed around a partfamily and their structure, in terms of both hardware and software, can bechanged quickly and cost-effectively to achieve the exact functionality and capacitydesired 3. Contain
28、ing several configurations to provide the neededflexibility andscalability, RMTs intrinsically lead to morecomplex machine tool design problems. Methodologies andtools that would help facilitate the design ofRMTs could highly benefit and encourage the employment of reconfigurable manufacturingsystem
29、s 4-6. One important aspect of the RMT design problem is developing dynamic models for the design, evaluation andcontrol of servo axes. What makes the problem ofmodelingRMTs unique is that even though there is a single machine tool,there exist several configurations, which separate models haveto be
30、精选学习资料 - - - - - - - - - 名师归纳总结 - - - - - - -第 14 页，共 24 页个人资料整理仅限学习使用developed for. Developing dynamic models for all possible configurations could be a cumbersome and time-consuming task if adhoc methods are utilized. Moreover, without a systematic methodology modeling would require alot of expert
31、ise and would be prone to errors, which woulddegrade the efficiency of using models in the design.In this paper we present a methodology that could help make the RMT modeling task less time demanding, less error-prone and less challenging. The key idea of this methodology is to take advantage of the
32、 modular structure of the RMTs andadopt modular modeling concepts into the RMT modelingmethodology. First, the physical components of an RMT aremodeled in a modular way using the bond graph modeling tool 7. The bond graph model is encapsulated in a schematic representation with defined connection po
33、rts. Then, theschematic component models are assembled by following thetopology of a given configuration to obtain the model of theconfiguration. The configuration model can be easily integratedwith the modules of non-energetic components such asinterpolators and controllers, which can be convenient
34、ly represented with block diagrams 。 however this is beyond thescope of this paper. BACKGROUND The RMT concept was introduced by Koren and Kota 2, and since their introduction, the design of RMTs has been anactive research area. Methodologies and tools for designingRMTs 4 as well as evaluating struc
35、tural stiffnesses 5 andtool tip errors 6 of design alternatives have been developed.However, the problem of developing a system level modelingmethodology for RTMs has not been addressed yet. Traditionally, machine tool models depict the machine toolas a group of servomotor and feed drive assemblies
36、that aremodeled as first or second order systems 8,9. Chen andTlusty, however, showed that the structural dynamics of thefeed drive could affect the system performance once high-speed machine tools are considered 10. Many researchersidentified the necessity to use higher order models for high-speed
37、machine tools to cope with structural dynamics in orderto be able to design the control system successfully 11-13.These publications clearly indicate that modeling a machinetool is not a trivial task and care must be taken when decidingon the complexity of the model, but they do not provide asystema
38、tic way of modeling and, therefore, remain applicationspecific approaches.There have been research efforts to help the design andcontrol of machine tool feed drives by automatically providingsimulation models. Wilson and Stein developed a softwareprogram called Model-Building Assistant to automatica
39、llysynthesize a minimum order model of the machine tool drivesystem for a given frequency range of interest (FROI 14. Thecomplexity of the model, which includes a flywheel, a torsionalshaft, a ballscrew, a ballnut, a DC motor, a torsional coupling, abelt-drive and a gear-pair as components, is autom
40、atically increased until the eigenvalues of the system fall beyond thespecified FROI. This work was a proof of concept for a model deduction algorithm and can not beapplied to any real machinetool system. However, such algorithm can be used 精选学习资料 - - - - - - - - - 名师归纳总结 - - - - - - -第 15 页，共 24 页个
41、人资料整理仅限学习使用to determinethe appropriate model complexity after the development of thesystem model.Gautier et al. have developed a software package calledSICOMAT(Simulation and Control analysis of MachineTools which helps with themodeling, simulation, modal analysis and controller tuning of one or two
42、decoupled or twocoupled machine tool axes 15. Their models describe thedynamics of the mechanical system by a number of masses andsprings. Thiswork makes the modeling of a machine tool process more systematic, and is therefore a valuable tool to themodeling engineer。 however, it lacks the generality
43、, modularityand flexibility that the RMT design methodology demands.The RMT modelingmethodologyFigure1shows the envisionedRMT modelingenvironment. It is desired to automate the task of RMT modeling, where the model of a given RMT configuration is automatically assembled from a library of modular com
44、ponent models.This way, all the candidate designs, which aregenerated either manually or automatically 4, can be modeledquickly and the models can be used toevaluate the candidatesin terms of their servo axis dynamic performance and help with their design.As Figure1 also implies, the modular compone
45、nt model library is a key part for the automated RMT modeling environment. Therefore, the first step of the proposedmethodology is to develop modular models for the componentsthat are used to generate the RMT configurations.This paperputs the emphasis on mechanical parts and discusses theirmodeling
46、in a modular way, because the energy interactionbetween themechanical components makes their modularmodeling more intriguing. Modular modeling of componentsthat only exchange signals, e.g. interpolators and controllers,presents a relatively simpler problem and are not discussedhere.To promote modula
47、rity and to be able to deal with theenergy interactions between the components and theirenvironment rather easily, bond graphs are utilized as themodeling language. Bond graphs provide a power-basedgraphical representation of a physical system. Moreover, bondgraphs describe different energy domains
48、in a unified way, which is a relevant advantage for RMT modeling, since theirservo axes may include components from different energy domains, such as mechanical, electrical or hydraulic.Bond graphs are only one level in the hierarchy of model representations used in this work. Underneath the bond gr
49、aphlevel the mathematical equations represent the physicalphenomena captured by the bond graph and this mathematical representation is the lowest level in the hierarchy. In the highestlevel bond graphs are encapsulated in a schematic representation, which not only allows for a compact representation
50、, but also shows the connection ports where themodel can interact with its environment. Figure 2illustratesthis hierarchy of model representations.In this paper all the models are shown in the schematiclevel, because the goal of this paper is not to discuss theirderivation, but rather to show what c
51、an be done once thosemodels are obtained.A detailed description of the models usedin this paper can be found in 16.In order to be able to cope with any spatial 精选学习资料 - - - - - - - - - 名师归纳总结 - - - - - - -第 16 页，共 24 页个人资料整理仅限学习使用motion that themechanical components may go through indifferent config
52、urations, models that capture the three-dimensional dynamics are used. Moreover, the initial assumption is made that in the mechanical domain all components can beadequately represented as rigid bodies.Figure 3 shows the schematic representation of a genericrigid body with N connection ports, which
53、is one of the main model modules in the library. The ports correspond to points ofinterest on the rigid body, where the physicalinteractions with the environment occur.Bonds (lines with half arrows are used to indicate that a port is a power port, i.e. thebody can exchange energy with its environmen
54、t through thoseports, whereas active bonds (lines with full arrows indicatesignal ports, i.e. only information is transferred through theseports.The model library also contains three-dimensional joint models that can be used to describe the relative motions between the component models.These joint m
55、odels are alsodeveloped in a modular way with ports, where they can beconnected to other model modules. The library offers two ways to express the constraints: (1 stiff springs and dampers can beused to implement more realistic constraints or to approximateideal constraints 。 (2 Lagrange multipliers
56、 can be introducedto express the constraints ideally. For a discussion of joint models the reader is also referred to 16.Once the model library is populated with some basicmodular rigid body and joint models, the modeling procedurecan be carried out as follows: The RMT components are brokendown into
57、 subcomponents and each subcomponent isassociated with a model in the library. If none of the model modules in the library can describe the subcomponent adequately, a new model has to be developed for that subcomponent and added to the library. Then, the models areassembled by following the topology
58、 of the components andusing the necessary joint models. Once a component model is obtained, it can be stored in the library for reuse. Finally, thecomponent models are assembled by following the topology ofa given configuration to obtain the model of that configuration.The process is illustrated in
59、Figure 4 as a flowchart and demonstrated in the following section through examples.EXAMPLES The following two examples give an overview of theproposed modeling methodology. The first example shows themodeling of a slide and the second example employs that slidemodel to develop a model for a RMT. The
60、 purpose of these examples is to give a general ideaabout how the modularity of the components can be exploitedin the modeling procedure, rather than to explain the details ofhow each (subcomponent can be identified and modeled.Therefore, the details of the model modules, such as their level of comp
61、lexity, are not discussed.Modeling a Slide A slide is a basic component of most machine tools,including RMTs.Different RMT configurations can beobtained by adding/removing slides to/from the configurationor by rearranging the existing slides in the configuration.Therefore, it is useful to demonstrat
62、e the modeling 精选学习资料 - - - - - - - - - 名师归纳总结 - - - - - - -第 17 页，共 24 页个人资料整理仅限学习使用procedureof a slide.Consider the slide shown in Figure 5. It is assumed that thecomponents are identified as shown in the figure. For thepurposes of this example, all the subcomponents except themotor can be modeled
63、 as rigid bodies with various number ofconnection points. The motor dynamics can be broken downinto two domains:the three-dimensional rigid body dynamicsof the housing and the electromechanical dynamics that drivethe relative rotational motion between the rotor and the stator.A model has been develo
64、ped for the motor that captures thedynamics in both domains and its schematic representation is given in Figure 6.Modeling the Arch-type RMT, which was developed by the NSFEngineeringResearch Center for ReconfigurableManufacturing Systems at the University of Michigan, is theworlds first full scale
65、RMT. It is a three-axis machine tool thatis designed around a part family with five different surfaceinclinations ranging from -15 to 45at 15increments and hasthe flexibility of doing machining operations such as milling and drilling at any of those angles.The reconfigurability of theArch-type RMT c
66、omes from the spindle unit, which can beconfigured at the five angles mentioned above by moving it along the curved guideway of the arch module and fixing it at any of the five locations on the arch module that are defined by mechanical stops.For the purposes of this example the base module is assum
67、ed to be identical to the ground and it has no effect on thedynamics of the machine tool. Theworktable, the column andthe spindle are essentially slides and their models are based onthe slide model given above. The arch is modeled as a rigid-body with a connection port for each mechanical stop.Final
68、ly,the model of the Arch-type RMT is assembled by following thetopology of the actual machine. Note that the figure shows the model for one of the configurationsonly. The models for the other configurations can be obtainedby changing the connection port of the arch model. Now that the model is assem
69、bled, the equations of motion can be derivedfrom the graphical model automatically, andsimulations can be performed.Although the mathematical model is ready, we cannot provide any simulation results in this paper due to the current lack of good estimates of systemparameters. Simulations can be carri
70、ed out easily once theparameter values are available.DISCUSSION In this paper, modular and hierarchical modeling concepts are identified asthe key characteristics of the RMT modelingmethodology. The modular structure of RMTs makes thismodeling approach beneficial, because the models contain allthe k
71、ey characteristics of reconfigurability 17:1. Modularity: The (subcomponents are modeled in amodular way 2. Integrability: The models can be integrated with othermodules through their connection ports 3. Customization: The level of detail included in themodel modules can be customized for individual
72、 components4. Convertibility: Models can be easily converted from one configuration to 精选学习资料 - - - - - - - - - 名师归纳总结 - - - - - - -第 18 页，共 24 页个人资料整理仅限学习使用another 5. Diagnosability: Model verification can be carried outeasily on model modulesThe approach presented in this paper allows for thesepar
73、ation of the modeling task into two steps:(1 Developingcomponent models。(2 assembling the configurationmodel. While the first step still requires a significant modeling expertise, the second step is much more systematic, and caneven be automated, which is left as a future work. Also, the two steps h
74、avedifferent focuses: The first step focuses on thedynamics within a component, whereas the second stepfocuseson the dynamics between the components.Compared to the existing approaches of servo axismodeling, where every different RMT configuration wouldpotentially be a new modeling problem, the appr
75、oach presentedin this paper allows for a faster development of configurationmodels. Configurations can be assembled quickly using themodel modules in the library, provided that all the componentsutilized in a given configuration have a corresponding modelmodule in the library. Therefore, having a co
76、mprehensivemodel library is essential for this methodology to be efficient.A three-dimensional multibody approach to modeling themechanical components of the machine tool promotesmodularity in the mechanical domain. Thus, for example, themodel of the machine tool slide can be used in anyconfiguratio
77、n without having a special slide model forcircumstances where the base of the slide is constrained to move in more restricted ways. With amultibody approach,generic component models can be created without a-prioriknowledge of the connectivity of the components.A drawback of the three-dimensional mul
78、tibody approachis, however, thatthe generic models might be more complexthan a certain configuration actually demands. For example, in a given configuration a component can be limited to a planarmotion only, in which case a three-dimensional model wouldbe overcomplex. The model should be simplified。
79、 otherwiseunnecessary complexity is retained in the model and reducesthe computational efficiency of the model. The proposedmodular modeling methodology would benefit from theintegration with a model order reduction algorithm. This willbe the focus of future work.Currently the bodies are considered
80、rigid, which is not always an adequate approximation. In order to be able to study the effects of the structural dynamics, flexible body modelsshould also be developed and included in the library.Finally, it is worthwhile to note that commerciallyavailable softwarepackages, such as ADAMS, DADS, EASY
81、5,Dymola etc, could also be used for the purposes of RMT modeling. However, to take advantage of the unified powerbased approach that the bond graphs provide and to make afuture model reduction easier to implement, bond graphs arechosen as the modelinglanguage.SUMMARY AND CONCLUSIONS A A modular mod
82、eling approach is proposed as a RMT modelingmethodology. 精选学习资料 - - - - - - - - - 名师归纳总结 - - - - - - -第 19 页，共 24 页个人资料整理仅限学习使用The components are modeled in amodular way, so that the modeling task of a given RMT configuration merely involves assembling the correspondingmodel modules together.Two exa
83、mples are given to illustratethe methodology, and advantages and disadvantages of this approach are discussed. The outcomes of this work indicate that a modularapproach to the problem of modeling RMTs can make themodeling process systematic and thus potentially more useful to practicing engineers if
84、 implemented in an automated modeling and design environment. However, there are stillchallenges, as highlighted in the discussion, that need to beaddressed before an automated modeling environment can beimplemented in a practical way. ACKNOWLEDGMENTS This work was supported by the EngineeringResear
85、chCenter forReconfigurable Manufacturing Systems of theNational Science Foundationunder Award Number EEC 9529125.REFERENCES 1 Mehrabi, M. G. and Ulsoy, A. G., 1997, State-of-the-Art in Reconfigurable Machining Systems , ERC/RMS TechnicalReport, University of Michigan, Ann Arbor2Koren, Y. and Kota, S
86、., 1999, Reconfigurable MachineTool , U.S. Patent 5,943,7503Landers, R. G., Min, B. K., Koren, Y., 2001,“Reconfigurable MachineTools”,Annals of the CIRP , Vol.50/1, pp. 269 2744 Moon, Y-M., 2000, Reconfigurable Machine Tool Design:Theory and Application , Ph.D. dissertation, Department ofMechanical
87、Engineering, The University of Michigan, Ann Arbor, MI 5 Yigit, A. S. and Ulsoy, A. G., 2002, “Dynamic StiffnessEvaluation for Reconfigurable Machine Tools IncludingWeakly Nonlinear JointCharacteristics”, Proc. IME, Part B:Journal of Engineering Manufacture , Vol. 216/B1, pp. 87-1016 Moon, S-K., 200
88、2, Error Predication and Compensationof Reconfigurable Machine Tool Using Screw Kinematics,Ph.D. dissertation, Department of Mechanical Engineering, TheUniversity of Michigan, Ann Arbor, MI 7 Karnopp, D. and Rosenberg, R. C., 1975, SystemDynamics: A Unified Approach , John Wiley & Sons8 Koren, Y., 1
89、984, Numerical control of machine tools,Khanna, Nai Sarak, Delhi9 Gross, H., 1983, Electrical feed-drives for machine tools,John Wiley & Sons.10 Chen, Y. and Tlusty, J., 1995, “Effect of low-frictionguideways and lead-screw flexibility on dynamics of high- speed machines”, Annals of the CIRP , Vol.
90、44/1, pp. 353-356 11 Pritschow, G., Bretschneider, J., Fahrbach, C., 1996,“Control of High Dynamic Servo Axes for Milling Machines”,Production Engineering , Vol. 3/1, pp. 63-68.12 Smith, D. A., 1999, Wide Bandwidth Control of High-Speed Milling 精选学习资料 - - - - - - - - - 名师归纳总结 - - - - - - -第 20 页，共 2
91、4 页个人资料整理仅限学习使用Machine Feed Drives , Ph.D. dissertation,Department of Mechanical Engineering, The University ofFlorida, Gainesville, FL13 Poignet, Ph., Gautier, M., Khalil, W., 1999, “Modeling,control and simulation of high speed machine tool axes”,IEEE/ASME International Conference on Advanced Inte
92、lligentMechatronics, pp. 617-62214 Wilson, B. H. and Stein, J. L., 1993, ModelBuildingAssistant: An Automated Modeling Tool for Machine Tool Drive Systems, Proceedings of the 1993 InternationalConference on Bond Graph Modeling, Vol. 25/2, pp. 169-17815 Gautier, M., Pham, M.T., Khalil, W., Lemoine, P
93、h.,Poignet, Ph., 2001, “SICOMAT: A system for simulation andcontrol analysis of machine tools”, IEEE/ASME InternationalConference on Advanced Intelligent Mechatronics, Vol. 1, pp.665-67016 Ersal, T., Stein, J. L., Louca, L. S., 2004, “A Bond GraphBased Modular Modeling Approach towards an AutomatedM
94、odeling Environment for Reconfigurable Machine Tools”,Proceedings ofthe1st International Conference on IntegratedModeling and Analysis in Applied Control and Automation(Part of the 1st International Mediterranean ModelingMulticonference, Genoa, Italy, October 28-3117 Koren, Y., Heisel, U., Jovane, F
95、., Moriwaki, T., Pritschow,G., Ulsoy, A. G., Van Brussel, H., 1999, “Reconfigurable Manufacturing Systems”,Annals of the CIRP, Vol. 48/2, pp.527-540精选学习资料 - - - - - - - - - 名师归纳总结 - - - - - - -第 21 页，共 24 页个人资料整理仅限学习使用精选学习资料 - - - - - - - - - 名师归纳总结 - - - - - - -第 22 页，共 24 页个人资料整理仅限学习使用精选学习资料 - - - - - - - - - 名师归纳总结 - - - - - - -第 23 页，共 24 页个人资料整理仅限学习使用精选学习资料 - - - - - - - - - 名师归纳总结 - - - - - - -第 24 页，共 24 页
