Design and Implementation of Distributed Numerical Control in Flexible Manufacturing System

To monitor, control and manage the work process of computer numerical control machine tools in a flexible manufacturing system (FMS) effectively, the distributed numerical coutrol (distributed-NC) software should be innovated with the characteristics of modularization and reconfiguration. In this paper, firstly, distributed-NC functions in the FMS environment are described. Then, we present a design and development method of the real time distributed-NC that is on the basis of the re-coufigurable software and hardware platform and with an object-oriented model concept. Finally, to verify the proposed method, the distributed-NC software has been implemented in VC++ 6.0 and has been tested in connection with the different physical flexible manufacturing shops.     

Architecture of Virtual Manufacturing based on Autonomous Manufacturing Islands

Virtual manufacturing (VM) is an integrated synthetic manufacturing environment exercised to enhance all levels of decision and control in a manufacturing networked enterprise. Autonomous manufacturing island (AMI) is an active, dynamic and flexible production cell in the domain of technology, organization and management. This paper explains the concept of VM, proposes the architecture of VM based on AMI and discusses its characteristics. Lastly, a pilot system of virtual manufacturing based on AMI is introduced.     

Interaction of Units and Research Methods of Control Performances of Distributed Manufacturing Information System

In order to analyze the function demand of the distributed manufacturing information system as well as its control demand, and eliminate information ambiguity among system units to integrate semantics, the abstract Agent model and computational structure of each unit was presented based on flexible coupling automata. The autonomy of each unit was investigated in this foundation. The system unit was described using the Web Ontology Language （OWL） ontology. And the system semantics was also integrated. On these basics the communication among the system units was analyzed with an example of interaction between a machine and a warehouse. The control performances of information system units were investigated using Boolean matrix as a substitute for traditional process in RW theory, which reduced the computational complexity. This work established the foundation for the demand analysis, design and development of the distributed manufacture information system.     

Distributed collaborative CAD system based on Web Service

This paper presents a novel Web Service based distributed collaborative CAD system employing feature as its collaborative design element and uses XML to define feature operations and communication protocol between the server and the client. To reduce network load and increase response ability of the system, the feature information is updated incrementally on the client. The system supports collaborative designing on heterogeneous platforms. Its framework and communication protocols are analyzed in detail. The experimental results from the developed prototype system showed that it can effectively support collaborative design under the distributed environment.     

Open Architecture of Single-processor Real-time Robot Control System Based on Windows NT

This paper introduces the architecture and implementation of an industrial robot control system based on Windows NT. This robot control system, which is based on a single-processor structure, can run on general industrial computers. Owing to using Windows NT's real-time extension RTX, the control system can achieve good realtime performance and friendly user interface in one general-purpose operating system. A three layer hierarchical architecture of control software is proposed to make the system more scalable and flexible. Furthermore a communication and configuration system is implemented to enable modules to communicate with each other, which make the control system scalable and flexible.     

Model Construct Based Enterprise Model Architecture and Its Modeling Approach

In order to support enterprise integration,a kind of model construct based enterprise model architecture and its modeling approach are studied in this paper.First,the structural makeup and internal relationships of enterprise model erchitecutre are discussed.Then,the concept of reusable model construct(MC) which belongs to the control view and can help to derive other views is propsed.The modeling approach based on model construct consists of three steps,reference model architecture synthesis,enterprise model customization,system design and implementation.According to MC based modeling approach a case study with the background of one-kind-productmachinery nanufactureing enterprises is illustrated.It is shown that proposal model construct based enterprise model architecture and modeling approach are practical and efficient.     

Intelligent Scheduling Controller Design for Networked Control Systems Based on Estimation of Distribution Algorithm

The use of communication networks in control loops has gained increasing attention in recent years due to its advantages and flexible applications. The network quality-of-service （QoS） in those socalled networked control systems always fluctuates due to changes of the traffic load and available network resources, This paper presents an intelligent scheduling controller design approach for a class of NCSs to handle network QoS variations, The sampling period and control parameters in the controller are simultaneously scheduled to compensate for the network QoS variations. The estimation of distribution algorithm is used to optimize the sampling period and control parameters for better performance. Compared with existing networked control methods, the controller has better ability to compensate for the network QoS variations and to balance network loads. Simulation results show that the plant setting time with the intelligent scheduling controller is reduced by about 64.0% for the medium network load and 49.1% for high network load and demonstrate the effectiveness of the proposed approaches.     

An Order-oriented Procedure Model for A Robust and Agile Production System

The manufacturing industry in 1990's is faced with se-vere challenge among the global competition for mar-kets.Production for a small quantity and high varietyeven lot-sizes of one-digit numbers products has be-come a main trend today.Traditional production proce-dure limits the flexibility of the production system.Inthis paper,based on the analysis of the procedure charac-teristics,a design strategy for re-usage of informationand resource is introduced,and an order-oriented pro-cedure model with concurrent,hierarchical and micro-cycle structure for a robust and agile production systemis proposed in order to realize flexible and adaptive pro-duction for dynamically-changing orders.     

异构环境中MMS协议的研究与实现

通过在Ｗｉｎｄｏｗｓ和ＵＮＩＸ这两种不同操作系统构成的异构环境中实现制造报文规范（ｍａｎｕｆａｃｔｕｒｉｎｇｍｅｓｓａｇｅｓｐｅｃｉｆｉｃａｔｉｏｎ,ＭＭＳ）通信的实例,探讨了如何在异构环境中实现ＭＭＳ通信的方法。介绍了ＭＭＳ的基本知识,特别是ＭＭＳ对象与服务的一般概念与特点;提出了一种ＭＭＳ客户／服务器系统的具体实现结构,并介绍了ＭＭＳ对象表示、ＭＭＳ服务实现、ＭＭＳ应用接口定义等;结合ＭＭＳ数控伴随标准,探讨如何将ＭＭＳ中抽象的对象与服务同具体数控设备的属性与操作对应起来,也即实际数控设备与ＶＭＤ的一般映射方法。所建立的ＭＭＳ通信系统能够提供面向制造设备的通用通信平台,从而有助于较好地解决车间层设备的信息集成问题。     

基于Web-MMS车间自动化通信模型设计与评价

在分析MMS以及Web服务技术的基础上,提出了车间控制系统的通信模型设计方法,构建了基于Web服务遵循MMS标准的车间控制系统通信模型.为了使车间控制通信系统具有实用性和可靠性等特点,进行了基于Web-MMS的通信模型的Petri网动态行为分析.在此基础上,进行了车间控制的通信原型系统的设计,并进行了通信模型的性能评价.分析结果表明,基于Web-MMS的通信模型设计方法是有效可行的.     

基于Client／Server结构打印服务系统设计和实现

介绍了基于Ｃｌｉｅｎｔ／Ｓｅｒｖｅｒ结构的具有灵活配置能力和良好可扩充性的打印服务系统ＣＯＳＩＸＬＰＶ１．０的总体框架．讨论了客户和服务器程序的结构和功能划分、打印执行结构的设计以及系统的定制和裁剪，并对系统实现作了简述     

柔性制造控制系统的并行设计方法

通过分析控制系统并行设计的支持环境，建立了控制系统并行设计支持环境的框架模型．从面向对象以及并行工程观点出发，提出了控制系统并行设计的策略，构造了以过程为中心，控制系统体系结构、数据、过程建模、用户界面／接口并重的面向对象的控制系统并行设计的工作流集成模型．在此基础上，描述了控制系统并行设计的实施内容和步骤．建立在上述设计方法基础上的柔性制造控制系统具有可重用性、可靠性、鲁棒性和开放性等特点．     

集成DCOM和CORBA的应用服务器设计与实现

采用Inprise的MIDAS技术，设计并实现了一个集成DCOM／CORBA的数据库应用程序服务器，能同时支持DCOM／CORBA用户对后台数据库的访问，并构造了DCOM和CORBA客户应用程序与其进行交互测试．该集成提供的这种新思路能充分利用Windows平台上丰富的软件资源和CORBA畀种平台的易通讯性．     

Component-based Control Software Design for Flexible Manufacturing System

A new method that designs and implements thecomponent-based distributed & hierarchical flexiblemanufacturing control software is described with acomponent concept in this paper. The proposed methodtakes aim at improving the flexibility and reliability ofthe control system On the basis of describing theconcepts of component-based software and thedistributed object technology, the architecture of the     

Analytical Results of Server Loads and Network Load in a General Client／Server System

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One-Stop服务的高校电子政务系统的构建

提出一种基于One—Stop服务的高校电子政务系统的体系结构，它使用三层瘦客户／服务器模式，对所有客户提供统一的入口界面，以及可以自定义服务功能，因而能够实现不同部门之间的事务协作处理。同时，探讨基于XML和DCOM的系统实现技术。     

基于COM/DCOM的分布式计算研究与应用

分布式计算技术在软件开发中得到了广泛的应用,它使复杂的大型网络应用程序变得易于开发。基于组件对象模型COM(Component Object Model)和分布式组件对象模型DCOM(Distributed COM)的组件技术是微软的分布式对象技术。通过详细地分析基于OM/DCOM组件技术的分布式计算的基本原理,总结了开发COM/DCOM组件的基本方法和三层分布式应用程序的实现过程。最后,给出了一个用COM组件构造的三层分布式应用系统实例。