A distributed laboratory based on object-oriented measurement systems

This paper aims to demonstrate how new network and software technologies are a suitable basis for building a geographically Distributed Measurement Laboratory. An architecture characterized by high reconfigurability, modularity, extendibility and re-usability is proposed. The hardware and software solutions are discussed in detail. The effectiveness of the proposed architecture is experimentally illustrated by an actual implementation.     

面向先进制造的分布式测量系统研究

针对现代先进制造业对测量系统的要求，本文提出了一种基于多Agent的分布式测量系统框架，该系统首先按其功能划分为6个不同的Agent，然后利用KQML作为通信语言、CORBA作为通信机制来执行多Agents间的交流和协作，具有互操作、合作性、智能性、开放性等特点，并选用火车轮尺寸检测线对其进行仿真。     

Web-based distributed manufacturing control systems

With the evolution of the application of web technology, agent-based manufacturing systems can be both easily implemented and become a potential approach for modern manufacturing enterprises. In this paper, we present problems and models required for the development of web-based distributed manufacturing control systems. The specific objectives are: (1) to propose an appropriate architecture for a web-based distributed manufacturing control system, (2) to define the specification of a web-based cell controller, (3) to design the co-operative mechanisms, contract net protocol, for better system performance, (4) to upgrade the communication capability of existing CNC machines from RS232C to TCP/IP (Transmission Control Protocol/Internet Protocol) based on Ethernet .To demonstrate the proposed development, prototype software based on ASP and VB programming was designed and implemented. As a result, not only is a great amount of time saved in the development of web-based manufacturing control software, but this development can also enhance the competitive capability of companies trying to operate on a flexible basis.     

Flow measurement system model with distributed resources

The paper describes a general flow measurement system model with distributed resources based on Distributed Component Object Model (DCOM). Complex flow-rate calculation procedures are decomposed and distributed throughout the measurement system. The paper explains to what extent a flow measurement process can be partitioned into the services that can be realized as separate objects shareable across the network. Certain measurement system components perform local measurements and/or calculations and communicate with a remote measurement system resource via intranet/internet. The measurement system comprises direct measurements of the primary measurement quantities, the calculation of the flow-rate and the calculation of the physical properties for various gases, gas mixtures, water and steam. Using DCOM the measurement system automatically activates the remote client/server components that carry out flow-rate calculations in real time. The measurement system covers different measurement procedures and a variety of primary elements. The performances of the measurement system model have been verified by realizing a measurement system with two measuring sections.     

Distributed measurement systems

In this paper the technologies that permit the development of distributed measurement systems over the internet are discussed. The different concepts of virtual instrumentation are summarized. Two different approaches to measurement system development are compared — the first is based on the commercially available environment , and the second, widely used in the research field, is based on the object-oriented programming.     

分布式测量系统动态时间性能测度方法

在网络制造环境下,动态时间性能是分布式测量系统的重要指标.针对基于公共对象请求代理结构和尺寸测量接口规范的分布式测量系统,根据多用户非抢占优先排队网络静态性能模型,提出基于无穷小摄动分析的分布式测量系统动态性能评价算法.算法以分布式测量系统时间性能指标的在线变化为输入,动态调整排队网络系统服务台的窗口数量,从而实现对系统时间性能的动态调整.最后,在某制造工厂中进行了应用实验,证明了算法的有效性.     

计量软件工程标准与准则

<正>目前,软件已成为众多测量系统中不可缺少的一部分。随着对系统功能的要求及测量不确定性的不断增加,软件变得更加复杂,因而更容易受到错误的影响。因此,对软件产品及软件设计程序的要求在软件质量评估中也变得更加重要,而标准和准则是确定这些要求的手段。本文概述了软件质量保证领域的标准化现状,着重介绍了检测、校准实验室应用软件的相关规则。     

A distributed architecture for automated manufacturing systems

The concept of distributed architectures for automated manufacturing systems is presented here. A modular architecture for a logical cell-controller is proposed where shopfloor level modules are incorporated in the cell control system so as to allow active co-operation for distributed decision making and control. Two examples illustrating distributed formulations for specific planning and control are presented. These examples demonstrate the feasibility and potential for distributed architectures for automated manufacturing. This work has been supported by a grant from the Institute of Manufacturing Research, Wayne State University, USA.     

On the control of distributed parameter systems using a multidimensional systems setting

The unique characteristic of a repetitive process is a series of sweeps, termed passes, through a set of dynamics defined over a finite duration with resetting before the start of the each new one. On each pass an output, termed the pass profile is produced which acts as a forcing function on, and hence contributes to, the dynamics of the next pass profile. This leads to the possibility that the output, i.e. the sequence of pass profiles, will contain oscillations which increase in amplitude in the pass-to-pass direction. Such behavior cannot be controlled by standard linear systems approach and instead they must be treated as a multidimensional system, i.e. information propagation in more than one independent direction. Physical examples of such processes include long-wall coal cutting and metal rolling. In this paper, stability analysis and control systems design algorithms are developed for a model where a plane, or rectangle, of information is propagated in the pass-to-pass direction. The possible use of these in the control of distributed parameter systems is then described using a fourth-order wavefront equation.     

分布式光纤瓦斯气体浓度测量的研究

利用光纤布拉格光栅的梳状窄带滤波特性,通过检测瓦斯的特征吸收谱线的方法来监测瓦斯气体的浓度,并且利用光纤光栅的空分复用和波分复用特性,实现多点分布式监测.通过多波长同时探测的方法提高系统分辨能力和精度.测量系统瓦斯气体的浓度测量范围为0～5%,测量精度大于0.1%,监测距离为50km.     

基于合作靶标的分布式测量系统定向方法

大尺寸分布式测量系统基于多源观测交会原理,测量节点间的相对位姿关系决定了系统整体性能.工作空间测量定位系统是分布式测量系统的典型代表,其定向方法借助激光跟踪仪的靶球互换性构建几何约束条件,导致系统接收节点存在不可避免的对心误差,影响定向精度.本文研究了一种移动式合作靶标的分布式系统定向方法.通过设计集成多接收节点的合作...     

摩托车车架反求工程中的数据测量

反求工程是通过重构产品零件的CAD模型,对原型进行修改和再设计,以达到设计创新、产品更新之目的.反求工程中如何根据样件特点和建模要求选取恰当的测量方法极为重要.同时,在进行三维坐标测量时,可以通过适当的规划测量布点,使测量数据满足必要性和充分性,为后期处理数据减轻负担,提高效率.通过摩托车车架的测量实践,为后续的建模和再设计获得高精度的测量值.     

Sampled-data control for linear time-delay distributed parameter systems

Some real systems have spatiotemporal dynamics and are time-delay distributed parameter systems (DPSs). The existence of time-delay may lead to system instability. The analysis and design of DPSs with time-delay is essentially more complicated. To take into account the factor of time-delay and fully enjoy the benefits of the digital technology in control engineering, it is a theoretical and practical value to consider the sampled-data control (SDC) problem of DPSs with time-delay. However, there are few attempts to solve the SDC problem of time-delay DPSs. In this paper, we introduce a SDC for linear time-delay DPSs described by parabolic partial differential equations (PDEs). A SDC design is developed in the formulation of spatial linear matrix inequalities (LMIs) by constructing an appropriate Lyapunov functional, which can stabilize exponentially the time-delay DPSs. This stabilization condition can be applied to either slowing-varying time delay or fast-varying one. Finally, simulation results of a numerical example are provided to illustrate the effectiveness of the proposed method.     

分布式协作系统快速可靠组播算法

为解决分布式协作系统中单点失效、实时性不高和对节点动态性支持不足等问题,提出一种基于网状拓扑结构的分布式协作快速可靠组播算法.该算法采用纯分布式协议来构建协作系统网状拓扑结构,各个协作对象根节点负责同步操作和记录日志信息.为降低协作数据传输延时,提高协作实时性,通过泛洪方式为每个协作节点构建冗余最短路径组播树进行协作数据分发;使用冗余对象根节点和传输链路来增强在节点动态加入和退出时协作系统的可靠性.最后,利用试验仿真对基于网状拓扑结构的快速可靠组播算法的分发延时和可靠性进行了验证.     

Web-enabled platform for distributed and dynamic decision-making systems

With the advent of internet and wireless technologies, real-time remote monitoring and control is becoming an essential need for meeting highly dynamic business objectives. At the same time, web-enabled platforms are required to perform remote monitoring with efficiently and effectively. Recent progresses on e-manufacturing applications address the needs for better integration between factory floor and enterprise systems. This paper presents a web-enabled platform which focuses on web-enabled intelligence to enable products and systems to achieve near-zero-downtime performance through device-to-business (D2B) platform. The proposed web-enabled platform can effectively minimize the massive information bottleneck that exists between plant floor and information systems. Case studies are presented to determine how effectively web-enabled industrial system can be used in factory floor as well as business decision-making. Manufacturers and users will benefit from the increased equipment and process performance with the effective implementation of the developed web-enable platform.     

Problems of measurement in soft systems

The paper reviews the problem of widely defined measurement in soft systems. It defines soft systems as those incorporating human activity, or describable by fuzzy logic. It considers examples from measurements in psychology, economics and psychology. A framework for considering measurement in soft systems is offered for discussion.     

基于LonWorks现场总线的分布式智能密度检测系统

本文介绍了一种基于LonWorks现场总线技术的分布式密度智能检测系统的设计方案。该系统采用Chip-Based结构,每个智能节点以MC143150为主处理器,PLT-22为收发器。系统中将采集来的温度和压力数据传送给神经元芯片,经其处理为密度数据后,经由收发器通过LON网络传输到上位机,实现了对密度的实时、准确及自动检测。     

A web-based distributed measurement system for electrical power quality assessment

Industries’ systems are shifting toward almost entirely sophisticated electronic devices. Power Quality (PQ) analysis is getting importance for the economy because this equipment is highly sensitive to PQ events. Control and supervision of an industrial process has mainly been focused on the electrical protection, and little attention has been paid to the quality of the electrical supplies. Nowadays, measurement and communications systems have advanced to enable the installation of web-based sensors within a PQ assessment scenario. In this sense, this paper presents an innovative low-cost measurement system, as well as investigates the challenges and trends in the development of distributed PQ measurement systems using smart sensors.