虚拟仪器的简介外文翻译.doc

中文3800字毕业设计(论文)外文资料翻译系 （院）：交通工程系专 业：车辆工程姓 名： 学 号： 外文出处：LabVIEW based Advanced Instrumentation Systems, 2007: 1-31(用外文写)附 件：1.外文资料翻译译文；2.外文原文。附件1：外文资料翻译译文虚拟仪器的简介Author : Grzegorz Polakqw , Mieczyslaw摘要：本文介绍了基于Lab VIEW软件虚拟仪器的技术特点和设计方法。虚拟仪器的关键技术是应用软件，仪器的主要功能多是由软件来实现的。所谓“软件即仪器”。目前设备多采用单一模拟器技术，无法真正实现装备的实际性能。使用虚拟仪器不但可以节约大量模拟设备的经费投入，而且能够提高质量与效率。与目前大多数模拟设备的经费投入，而且能够提高质量和效率。与目前大多数模拟设备相比，虚拟仪器能够让使用人员主动参与生产过程甚至设计过程。有利于使用者进行主动和与探索式学习。关键词：虚拟仪器 Lab VIEW 设计 学习目标读者在完成本章阅读将有下面一个了解：虚拟仪器的历史虚拟仪器的演变虚拟仪器的定义虚拟仪器的体系结构Lab VIEW的演变使用Lab VIEW创建的虚拟仪器Lab VIEW的优势虚拟仪器在发动机工程的应用超越个人电脑的虚拟仪器1.1简介一种基于用户从环境或从被测单元收集数据，并显示信息的一种仪器，这样一种仪器可以采用变频器来测试如随着温度或压力的变化的物理参数的变化，采集信息并将其转换成相应的电信号，例如电压和频率的变化。这种仪器也被定义为一种物理软件设备。它对获得的来自另一台仪器的数据进行分析和处理，然后在显示器或录音设备上输出数据，这种记录仪包括示波器，频谱分析仪等。基于对源数据的收集和分析的这种形式仪器得到广泛应用。1.2虚拟仪器简介虚拟仪器是一个跨学科领域，包括温度、压力、距离、光和声音的频率和振幅，以及包括电压、电流和频率在内的电气参数。为了创建用于灵活控制和监控的精密仪器，其兼有了传感、硬件和软件技术。虚拟仪器的概念诞生于19世纪70年代后期，当时随着微处理器技术的完善使一台机器的功能更容易被使用，其软件更改也更方便。虚拟仪器的灵活性在很大程度上取决于专用硬件。通常，只有应用特定的程序，将信号调理模块和模拟数字转换器作为接口，连接到外部仪器中使用，因此，计算机或使用专门的板载，控制和采集数据的处理器的仪器，不能简单定义为虚拟仪器。随着在生物技术越来越复杂的应用，利用虚拟仪器可以有效的降低技术设备和生产成本。虚拟仪器得到更加深入的研究。1.3虚拟仪器的历史从历史上看，虚拟仪器系统和测量棒、温度计和尺度一样，都起源于遥远的过去。到了近代，虚拟仪器系统已普遍运用到几乎所有设备，例如，一个由机电压力表传感器连接到另一个传感器的信号调理电路，从信号处理、输出到显示器面板，也许能形成一条记录，其中的微量元素对不断变化的条件，通过机械手臂相联系到一个旋转的滚筒，创造一种随压力变化的时间纪录。但是，直到20世纪80年代采用应用程序，由单一路线到中央控制面板，才组成了一个阵列显示物理数据，利用计数器装置连接开关旋钮套、物理仪器和个别按钮控制的复杂系统才得以应用，例如过程控制。1.4 虚拟仪器的演变因为虚拟仪器技术结合主流商业技术，结合灵活的软件和多种便于控制的硬件设备的电脑技术，所以工程师和科学家们可以创建用户定义的系统，以满足他们的具体应用需求。利用虚拟仪器，工程师和科学家们可以缩短开发时间，设计更高品质的产品，并降低设计成本。一种集合数据收集、工具种类繁多、电脑化控制和操作的仪器被设计，并在商业市场上广泛流通，就是现在所谓的“虚拟仪器。“1.5 早期挑战虚拟仪器是必要的，因为它提供了适用于当今的概念：产品和工艺设计，开发和交付所需的快速适应性检测仪器。只有在虚拟仪器的条件下，工程师和科学家才可以创建自己需要的模块，才能跟上世界的要求。1.6 虚拟仪器虚拟仪器提供了一个测量和自动化系统建设的新模式，并成为主流。其成功的关键包括电脑技术的快速进步、爆炸性的低成本、高性能数据转换器（半导体）的开发以及系统设计软件的出现。这些因素为用户访问虚拟仪器系统提供了非常广泛的基础。虚拟仪器系统是一个由用户控制，通过电脑桌面操作，发展起来用于电脑测试，用于控制硬件服务和信息输出或者数据记录，并在电脑屏幕上显示的技术系统，其利用桌面计算机的外部设备接口收集和整理测试和测量数据。虚拟仪器还扩展到基于PC系统的用于控制、收集和处理数据的程序电脑化仪器系统。也有几个在公开文献对虚拟仪器的定义。桑特定义为“具有一般功能，具有特定程序的一种虚拟工具。”戈德堡介绍说，“虚拟仪器是一些专门的亚基组成，一些通用的电脑，一些软件，和一个小诀窍“。虽然是非正式的，但这些对虚拟仪器定义却具有一般概念的基本思想，即虚拟与足够的资源，“如果我们只是模拟，加载其他计算机软件的话，那么任何计算机都可以模拟任何其他计算机。”这种普遍性介绍了虚拟仪器的基本功能属性：通过软件更改的形式，使用户能够将其功能修改以满足广泛的应用。虚拟仪器是由以下模块组成：传感器模块、传感器接口、信息系统的接口、处理模块、数据接口、用户界面。一个有效的用户界面,展示了对虚拟仪器的控制效率和检测精度，影响操作者对于测量结果的解释。因为电脑的使用界面比传统仪器的用户界面更容易影响和改变，就有可能购买更多的演示效果，为用户界面进行自定义。根据报告和互动功能，我们可以将虚拟仪器的接口分为四类：终端用户界面、图形用户界面、多通道用户界面和虚拟与增强现实接口。集成功能的模块限制了虚拟仪器的灵活性。最简单，最灵活的表达方式，就是建立一个为一个单一的、单片的应用程序软件，采用物理的方法集合为一体的综合虚拟仪器，这种方法能达到最佳的性能，但是维护和制作困难，因此，一个被认为在建模和设计时，面向对象的设计仪器，它更方便地使用模块化组成。虚拟仪器的每一个模块，都能结合其他对象，利用虚拟仪器的界面实现数据信息交换。类似的做法是面向组件的方法，其中，除了元件对象的逻辑分离外，它们在物理上也在不同的单元放置，以便重用。另一种方法，在其基本理念到面向对象的方法相似，是一种非常规的采用内分层控制器方法来解决传感器模块功能集成结构的耦合模式。这种传感器模型应用于很多领域，包括对人体生理信号的传感器电交互系统。在这种传感器的互动模式，从遥感的原始数据流，例如脑电图（EEG）的数据，经过最多两个信号预处理，然后才传递到任意一个应用程序或直接到主体的水平。第二个是允许选择的命令层，允许将即插即用功能一样复杂的处理机制整合起来，发挥组织更灵活的功能来需求解决方案被应用于虚拟仪器数据处理。1.7 Lab VIEW的演变任何虚拟仪器的核心都是灵活的软件，世界上最好的虚拟仪器软件平台之一 Lib VIEW，即实验室虚拟仪器工程工作台的扩大的缩写。 Lab VIEW的确是一个强大的信号采集、测量分析和数据演示，没有了传统开发工具的复杂性的一种灵活性的编程语言，提供了一种图形化开发环境。1986年，美国国家仪器公司将虚拟仪器引入Macintosh，它具有快速性和一致性，作为一种高效、功能强大的编程语言持续吸引了工程师和科学家在测试、控制和设计中的应用。如今，虚拟仪器是数千名工程师和科学家首选的图形化开发环境。有了合适的软件工具，工程师和科学家们可以高效地创建自己的应用程序，通过设计，可以整合一个特定的进程，适合自己需要的例程。他们还可以创建一个最适合应用程序目的的和那些可以进行交流的相应的用户界面。他们可以定义怎样、何时从设备获取信息、如何处理、操纵和存储数据、结果如何呈现给用户。凭借强大的软件，我们可以将连续的做出结果的程序输入到仪器，使其适应信号的变化或者利用或多或少的处理能力显示必要的结果。1.8使用Lab VIEW创建的虚拟仪器Lab VIEW是虚拟仪器的一个组成部分，因为它提供了一个工程师和科学家在考虑具体应用需要的、易于使用的开发环境。Lab VIEW提供了更容易连接到其他的硬件和软件的各种强大的功能。图形化编程是Lab VIEW提供工程师和科学家最强大的特性之一。在Lab VIEW的条件下，用户可以通过一个在计算机屏幕上创建的图形用户界面，自定义虚拟仪器，通过它人们可以实现：开发仪器的实用程序、控制选定的硬件、获得数据的分析、显示结果。1.9 Lib VIEW 的优势对软件的选择很重要，因为软件是整个系统的的核心组成部分。选择合适的软件可以最大限度地提高生产率，同时一个软件如果不适应需要则会消耗时间和生产力。Lab VIEW可帮助用户从开始到完成的过程中利用更少的时间完成更多的工程。相对于其他开发软件，Lab VIEW有几个方面有助于提高生产力。例如易学易用等。1.10超越个人电脑的虚拟仪器近日，商用PC技术已经被应用到嵌入式系统。例如Windows CE中， Intel x86处理器，PCI和Compact PCI总线，嵌入式以太网开发。由于虚拟仪器严重的对商业成本和性能优势技术依赖，它也被扩大到具有更多的嵌入式的和实时的能力。举例来说，Lab VIEW在Linux上的运行，就像嵌入式电子投标系统从Ventur COM的实时嵌入式操作系统的具体指标体系一样自然流畅。虚拟仪器的使用可以通过安放在系统中的一个工具箱，放在桌面上的一个嵌入式系统中。一个一人注目的技术变化、影响嵌入式系统开发的是计算机网络设计体系和网络交流。随着电脑的普及，以太网现在已经成为全球公司和企业的标准基础设施。综述虚拟仪器在日新月异的计算机技术推动下日益强大，在一个开放的框架的基础上提供我们更多力量，去创建和定义更多的系统。这个概念不仅确保了成果在未来的使用，而且也提供了更多的灵活性，以适应需求的变化和扩展。虚拟仪器的设计在科学家和工程师利用Lab VIEW的不断开发和完善下，创造了更亲近的开发环境和更强大的功能。最后，它提供了用于用户设计自定义的进一步加强直观界面的虚拟仪器系统软件。Lab VIEW就是此类软件的例子。Lab VIEW生动的开发环境，提供了具有表现性和灵活性的编程语言，特别是在测量和自动化应用上，提供了高水平的函数关系和实用工具。 附件2：外文原文（复印件）Introduction to Virtual Instrumentation Author : Grzegorz Polakqw , MieczyslawAbstract : The technique characteristics and the design methods of virtual instrument on Lab VIEW software are introduced. The key techniques of the virtual instrument is software, the main function of the instrument is realized by the software, so called software namely instrument . The weapon equipments cannot realize its real performance because o f its single simulator technology. Use of virtual instrument couled not only save a great quantity of funds for equipments, but also increase the quality and efficiency. The people w ho use the virtual instrument can take participate in the equipments procedure of produce and design. Key Words: virtual instrument Lab VIEW design Learning Objectives. On completion of this chapter the reader will have a knowledge on:History of Instrumentation SystemsEvolution of Virtual InstrumentationPremature Challenges of VIDenition of Virtual InstrumentationArchitecture of Virtual InstrumentationEvolution of Lab VIEWCreating Virtual Instruments using Lab VIEWAdvantages of Lab VIEWVirtual Instrumentation in the Engineering ProcessVirtual Instruments Beyond the Personal Computer1.1 IntroductionAn instrument is a device designed to collect data from an environment, or from a unit under test, and to display information to a user based on the Collected data, Such an instrument may employ a transd user to sense changes In a physical parameter, such as temperature or pressure, and to convert the Sensed information into electrical signals, such as voltage or frequency variations. The term instrument may also be dened as a physical software device .That performs an analysis on data acquired from another instrument and then outputs the processed data to display or recording devices. This second category of recording instruments may include oscilloscopes, spectrum analyzers, and digital millimeters. The types of source data collected and analyzed by Instruments may thus vary widely.1.2 Introduction to Virtual Instrumentationtemperature, pressure, distance, frequency and amplitudes of light and sound, and electrical parameters including voltage, current, and frequency. Virtual instrumentation is an interdisciplinary eld that merges sensing, hardware, and software technologies in order to create exible and sophisticated instruments for control and monitoring applications. The concept of virtual instrumentation was born in late1970s,when microprocessor technology enabled a machines function to be more easily changed by changing its software. The exibility is possible as the capabilities of a virtual instrument depend very little on dedicated hardware commonly, only application specic signal conditioning module and the analog-to-digital converter used as interface to the external world. Therefore, simple use of computers or specialized onboard processors in instrument control and data acquisition cannot be dened as virtual instrumentation. Increasing number of biomedical applications use virtual instrumentation to improve insights into the underlying nature of complex phenomena and reduce costs of medical equipment and procedures.1.3 History of Instrumentation SystemsHistorically, instrumentation systems originated in the distant past, with measuring rods, thermometers, and scales. In modern times, instrumentation systems have generally consisted of individual instruments, for example, an electromechanical pressure gauge comprising a sensing transducer wired to signal conditioning circuitry, outputs a processed signal to a display panel and perhaps also to a line recorder, in which a trace of changing conditions is linked onto a rotating drum by a mechanical arm, creating a time record of pressure changes. Complex systems such as chemical process control applications employed until the 1980s consisted of sets of individual physical instruments wired to a central control panel that comprised an array of physical data display devices such as dials and counters, together with sets of switches, knobs, and buttons for controlling the instruments.1.4 Evolution of Virtual InstrumentationVirtual instrumentation combines mainstream commercial technologies, such as the PC, with exible software and a wide variety of measurement and control hardware, so engineers and scientists can create user-dened systems that meet their exact application needs. With virtual instrumentation, engineers and scientists reduce development time, design higher quality products, and lower their design costs. A large variety of data collection instruments designed specically for computerized control and operation were developed and made available on the commercial market, creating the eld now called “virtual instrumentation.”1.5 Premature ChallengesVirtual instrumentation is necessary because it delivers instrumentation with the rapid adaptability required for todays concept, product, and process design, development, and delivery. Only with virtual instrumentation can engineers and scientists create the user-dened instruments required to keep up with the worlds demands.1.6 Virtual InstrumentationVirtual instrumentation achieved mainstream adoption by providing a new model for building measurement and automation systems. Keys to its success include rapid PC advancement; explosive low-cost, high-performance data converter (semiconductor) development; and system design software emergence. These factors make virtual instrumentation systems accessible to a very broad base of users.A virtual instrumentation system is a software that is used by the user to develop a computerized test and measurement system, for controlling an external measurement hardware device from a desktop computer, and for displaying test or measurement data on panels in the computer screen. The test and measurement data are collected by the external device interfaced with the desktop computer. Virtual instrumentation also extends to computerized systems for controlling processes based on the data collected and processed by a PC based instrumentation system.There are several denitions of a virtual instrument available in the open literature. Santori denes avirtual instrument as “an instrument whose general function and capabilities are determined in software. ” Goldberg describes that “ a virtual instrument is composed of some specialized subunits, some general-purpose computers, some software, and a little know-how”. Although informal, these denition capture the basic idea of virtual instrumentation and virtual concepts in generalprovided with sufficient resources, “ any computer can simulate any other if we simply load it with software simulating the other computer .” This universality introduces one of the basic properties of a virtual instrumentits ability to change form through software, enabling a user to modify its function at will to suit a wide range of applications.A virtual instrument is composed of the following blocks:Sensor moduleSensor interfaceInformation systems interfaceProcessing moduleData base interfaceUser interfaceAn effective user interface for presentation and control of a virtual instrument affects efficiency and precision of an operator do the measurements and facilitates result interpretation. Since computers user interfaces are much easier shaped and changed than conventional instruments user interfaces, it is possible to employ more presentation effects and to customize the interface for each user. According to presentation and interaction capabilities, we can classify interfaces used in virtual instrumentation in four groups:Terminal user interfacesGraphical user interfacesMultimodal user interfaces andVirtual and augmented reality interfacesFunctional integration of modules governs exibility of a virtual instrument. The simplest, and the least exible way, is to create a virtual instrument as a single, monolithic application with all software modules of the virtual instruments logically and physically integrated. This approach can achieve the best performance, but makes difficult maintenance and customization. Therefore, it is more convenient to use modular organization. An object-oriented method was identied as natural approach in modeling and design of instruments. Each module of a virtual instrument is then implemented as an object with clearly dened interface, integrated with other objects using message interchange. Similar approach is component-oriented approach, where, in addition to logical separation of components into objects, they are physically placed into different unit to allow reuse. Another approach, similar in its basic idea to the object-oriented approach, is a structural coupling paradigm for nonconventional controllers that dene the layered approach to functional integration of sensor modules. This sensor model was applied in many domains, including electrophysiological interaction systems with sensors for human physiological signals. In this sensor interaction model, a stream of rawdata from the sensing hardware, for example electroencephalogram (EEG) data, passes through up to two levels of signal preprocessing before it is either passed to an application or presented directly to a subject. Second command layer, which is optional, allows more exible organization of data processing and plug-and-play like integration of complex processing mechanisms into a virtual instrument solution.1.7 Evolution of Lab VIEWAt the heart of any virtual instrument is exible software, and National Instruments invented one of the worlds best virtual instrumentation software platforms Lab VIEW expanded as Laboratory Virtual Instrumentation Engineering Workbench. Lab VIEW is a powerful graphical development environment for signal acquisition, measurement analysis, and data presentation, giving the exibility of a programming language without the complexity of traditional development tools. Since1986, when National Instruments introduced Lab VIEW for the Macintosh, it has quickly and consistently attracted engineers and scientists looking for a productive, powerful programming language to use in test, control and design applications. Today, Lab VIEW is the preferred graphical development environment for thousands of engineers and scientists. With the right software tool, engineers and scientists can efficiently create their own applications, by designing and integrating the routines that a particular process requires. They can also create an appropriate user interface that best suits the purpose of the application and those who will interact with it. They can dene how and when the application acquires data from the device , how it processes, manipulates and stores the data, and how the results are presented to the user. With powerful software, we can build intelligence and decision-making capabilities into the instrument so that it adapts when measured signals change inadvertently or when more or less processing power is required.1.8 Creating Virtual Instruments Using Lab VIEWLab VIEW is an integral part of virtual instrumentation because it provides an easy-to-use application development environment designed specically with the needs of engineers and scientists in mind. Lab VIEW offers powerful features that make it easy to connect to a wide variety of hardware and other software. Graphical Programming is one of the most powerful feature that Lab VIEW offers engineers and scientists. With Lab VIEW, the user can design custom virtual instruments by creating a graphical user interface on the computer screen through which one can:Operate the instrumentation programControl selected hardwareAnalyze acquired dataDisplay results1.9 Advantages of Lab VIEWThe choice of software is important because software is generally the central component that ties the entire system together. Choosing the right software can maximize productivity, while a software package that does not tthe needs could drain time and productivity. Lab VIEW helps the user to do more projects done in less time, by streamlining the process from inception through completion. There are several areas in Lab VIEW that contribute to a signicant gain in productivity when compared to other development software . for example easy to learn, easy to use,1.10 Virtual Instruments. Beyond the Personal ComputerRecently, commerci