电气工程专业英语考试

1、.：.；While we appear to prefer the total objectivity of a mathematically formulated method of signal processing, it is now well proven that the AI methods often are better choices to use in terms of better speed of performance and often lower cost of processing. 当我们似乎更喜欢信号处置数学方法的整体客观性，如今证明，为了得到更好的速度性

2、能和低本钱的处置，人工智能方法经常是更好的选择。Often they are the only solution since the algorithmic approach cannot be deployed because of the lack of a suitable mathematical formulation or powerful enough processor to run the algorithm. 经常当算法由于缺乏适宜的数学表达式和足够强大处置器去运转算法而不能展开时，他们是独一的处理方案。Signal processing in the modern ins

3、trument, therefore, will often make use of many different methods. This account is an introduction to the characteristics of the various forms and is written to assist selection. Space limitations prevent presentation of each kind in detail. 因此，在现代仪器中的信号处置通常会运用许多不同的方法。这个阐明只是对各种方式特征的一个引见并被书写出来以协助 选择。

4、空间的限制阻止了各种方法的详细引见。Traditionally the most popular method used to develop mapping models is that of mathematical modeling. 传统上用于开发映射模型中最受欢迎的方法是数学建模。The mathematical model is usually what is sought, as it provides the highest level of understanding about the subject and the most precise representation

5、of the behavior. 探求数学模型以提供课题最高程度了解和性能最准确的表达。The major disadvantage of mathematical models is that they can quickly become so complex that implementation of these models in measurement systems is often impractical. 数学模型主要的缺陷是迅速变得复杂，以致在丈量系统中这些模型运转通常是不能实现的。 In this class, the single, or set of multiple

6、, input signal(s) to the data processor is converted to the output form using tightly formulated mathematical description. 在这类，单一的或多个输入信号的数据处置经过亲密运用数学描画转化为输出方式。This relationship is called the algorithm. Strict relationships hold; the relationship is said to be formal, meaning that for any given inpu

7、t the output will always be the same. The algorithm supports only one interpretation. 这种关系被称为所谓的算法。严厉关系约束，关系可以说是有条理的，也就是说，对于恣意给定输入输出将永远是一样的。算法只提供一种诠释。 This method of signal processing is the most highly developed method and is certainly one to aim for because it is devoid of ambiguity. 信号处置的方法是最高速开展

8、的方法，必然以毫无歧义为目的的。All will agree on how it will respond. It carries a comforting level of understanding and, thus, acceptance. 一切方法对如何呼应获得了一致意见。它能到达一个令人欣喜的了解程度，从而接受它。Algorithmic methods can be very accurate, traceable, and can be calibrated with relative ease and agreement. 计算方法可以是非常准确的，可描画的，并能较容易地调整并

9、达成一致。They are the basis of many instrumentation systems. The origin of their use in instrumentation goes back to the early days of computing using, first, mechanical computational machines (late 1800s to around 1930) and then analog electric devices (early 1900s to 1960s), all of which were mostly r

10、eplaced by the use of digital computers commencing around 1950. 他们是许多仪器系统的根底。在仪器中，他们运用的来源可追溯到的早期的计算机运用，首先，机械计算机器(19世纪后期到1930年)，然后到模拟电子设备(20世纪初到20世纪60年代)，一切这些都从大约1950年开场由于数字计算机的运用而被替代。All of these algorithmic methods of processing can be simplistically regarded as embodiments of a mathematical equati

11、on inside a suitable technological machine.embodiments 表达；化身；详细化mathematical equation 数学方程式 一切的这些处置方法可以简单地看成是一个包含适当的技术设备的数学方程详细化。As the demands complexity and performance requirements grew over time, so the did the demands on the detail of the algorithm and the means to model it inside a computation

12、al machine. 随着时间过去，由于需求复杂性和性能要求的增长，所以在计算机器里对算法细节和模型方法有要求。Mathematical description eventually reaches limits of definition as the models push the boundaries of mathematical methods and human development. Too often, this arises before adequate detail is able to be built into the model. The algorithm i

13、s then an inadequate model of the need. 当模型推进数学描画方法和人类开展的界限，数学描画最终到达定义极限。通常，适当的细节可以被构造进模型之前产生。算法是由于模型缺乏而产生的需求As the algorithm increases in complexity, the processing power needed must be increased to maintain both fidelity and speed of processing. 随着算法复杂度的增长，处置才干必需提高以坚持准确和处置速度。Despite great advances

14、 being made in algorithm development and in computer power, the algorithmic methodology eventually encountered mathematical and technological barriers in many fields. 虽然在算法的开展和计算才干上得到提高，在许多领域算法的方法论最终遇到数学上和技术上的壁垒The method is seen to not always be the best to use because of lack of an adequate algori

15、thm or the high cost of computing. 研讨方法由于缺乏适当的算法或由于高本钱的计算不能得到最好地运用。In instrumentation, another factor also arises. Fast, detailed processing brings with it the need for increasing electrical bandwidth requirements in signal transmission. This increases implementation costs and also eventually reache

16、s technological constraints. 在仪器上，另外一个要素也出现。在信号传输上快速的详细处置导致需求添加电气带宽要求。添加的施工本钱也最终到达技术限制。Fortunately the solutions that may overcome these limiting constraints in many circumstances were developing in other fields under the general name of artificial intelligence (now called applied intelligence in en

17、gineering), as new forms of mathematics and in other fields, such as decision theory. 侥幸的是在很多情况下可以抑制这些约束限制的处理方案在人工智能的其他领域中开展 (如今称为“工程上的人工智能)，作为数学和其他领域的新方式，如决策论。Principally, a key limitation of the algorithmic method is that its unforgiving level of formalism carries with it a depth of processing exa

18、ctitude that is often not warranted. 主要来说，一个算法的关键的局限性是它方式主义过于苛刻的程度极大地影响了它处置精度的深度。Other methods have emerged that allow vaguely subjective, as opposed to tightly objective, processing to be applied to good effect. 其他方法表现出允许模糊的客观，而不是严谨的客观，运用效果良好。There AI methods have gradually gained acceptance to the

19、 degree that many are now routinely used and are supported by dedicated applications software and electronic integrated circuitry. 人工智能方法在一定程度上逐渐获得接受，以致于如今许多被日常运用，并受专门运用软件和电子集成电路支持。At first, these many alternatives were seen to be isolated methods. Gradually, the literature has shown trends to merge

20、 them in pairs. 首先，许多项选择择被看做是独立的方法。渐渐地，文献显示出成双交融的趋势。Their use in a more widely mixed form is still limited. This account seeks to give a comprehensive appreciation of the commonly met AI processing methods by placing them into relative perspective. 在一个更广泛的混合方式中运用依然遭到限制。经过把他们放在一个相对的角度上，这个阐明试图给出一些常见的人

21、工智能的处置方法的综合评价It is interesting to contemplate that natural world computing in animals does not appear to make much use of algorithmic methods, but does make extensive use of the methods presented here in the AI class. 令人感兴趣的是以为在动物实验中自然界计算似乎不会大量运用的算法，但这里提供了在人工智能中广泛运用的算法。The paradigm invoked here is t

22、hat experience has shown that informal methods based on knowledge-based systems (KBS) can produce mappings of many inputs to one by use of less than completely formal description. 这里是调用的范例展现了这样的阅历，基于知识系统(KBS)的一些常用方法可以经过运用不完好的方式描画产生多种输入到一个输出映射。The AI methods can yield surprisingly efficient solutions

23、 to previously unsolved needs. They often can outperform algorithmic methods or carry out a similar task with far less computing power. 人工智能方法能提供惊人的有效方案去处理以前未处理的需求。他们往往比计算方法好或是用更少的计算才干就可执行类似义务。They are all associated with multiple input processing and can be applied to forming decisions from data su

24、pplied by sensors. Each situation has to be judged on the balance between use of computing effort and effective processing. 他们与多重输入处置有关并运用于将经过传感器提供的数据构成决策。每个情况经过平衡计算量的运用和有效的处置进展判别。On the downside, they lack formality and thus may be very hard to calibrate and authenticate. They, not having adequate

25、scientific foundation and a solid formal base of operation, are not easily accepted as “sound. 不利的一面是他们缺乏方式，因此能够很难进展调整和验证。他们没有充足的科学根底和坚实的正式运转根底，不能随便地以为是 “可靠的而被接受。They are often hard to comprehend by a second party, for their description is not always adequately documented or done to any agreed conve

26、ntion. As their principles vary widely, they must be well understood before application is developed. 他们往往很难被另一流派了解，由于他们的描画并没有充分的文件可证明或做任何商定公约所规定。随着他们的原理广泛改动，他们必需在广泛运用之前被深化了解。 For all of these negative factors, they often are able to provide “more performance for less cost and thus will be increasin

27、gly adopted. 对于一切这些不利要素,他们往往能提供“更多的性能以得到低本钱，从而越来越多地采用。 Their rising level of use should not suggest the algorithmic methods will become obsolete, but more that the instrument designer now has a much larger set of processing tools available. 运用的继续晋级并不阐明算法成为过时，但如今仪器设计者有更多的可用途置工具。Unit 12 Simple Instrum

28、ent Model简易的仪器模型In addressing measurement problems, it is often useful to have a conceptual model of the measurement process. This unit presents some of the fundamental concepts of measurement in the context of a simple generalized in strument model. 在处理丈量问题的过程中，一个丈量过程的概念模型经常是很有用的。在丈量仪器模型简单概括的情况下，本单

29、元引见一些丈量的根本概念。Fig.12.1 presents a generalized model of a simple instrument. The physical process to be measured is in the left of the figure and the measurand is represented by an observable physical variable X. Fig.12.1提出了一种简易仪器的概念模型。物理过程在左边的图形中进展丈量，被测变量以一种可观测的物理变量X描画。Note that the observable variab

30、le X need not necessarily be the measurand but simple related to the measurand in some known way. 需留意的是，观测变量X不需求一定是个被测变量，而是在一些知的方法中简简与被测变量相关。For example, the mass of an object is often measured by the process of weighing, where the measurand is the mass but the physical measurement variable is the d

31、ownward force the mass exerts in the Earths gravitational field. There are many possible physical measurement variables. A few are shown in Table 12.1. 例如，物体的质量通常是经过称重来丈量，被测变量是物体但是实践丈量变量却是地球引力场作用于物体的向下的引力。一些可以在表12.1中看出。The key functional element of the instrument model shown in Fig.12.1 is the senso

32、r, which has the function of converting the physical variable input into a signal variable output. 在图.12.1中仪器模型的中心功能部件是传感器，它的功能是将物理变量输入转换成信号变量输出。 Signal variable have the property that they can be manipulated in a transmission system, such as an electrical or mechanical circuit. 在传输系统中信号变量具有可操作的特性，如

33、电子回路或机械电路。Because of this property, the signal variable can be transmitted to an output or recording device that can be remote from the sensor. 由于这个特性，信号变量可以被传送到一个远离传感器的输出或记录安装。 In electrical circuits, voltage is a common signal variable. In mechanical systems, displacement or force are commonly use

34、d as signal variables. 在电路中，电压是一种常见的可变信号。在机械系统、位移和力通常被用做信号变量Other examples of signal variable are shown in Table 12.1. The signal output from the sensor can be displayed, recorded, or used as an input signal to some secondary device or system. 信号变量的其他例子展如今表12.1。从传感器输出的信号可以被显示、记录或者被用作为一个输入信号传输到一些次要设备

35、或系统。 In a basic instrument, the signal is transmitted to a display or recording device where the measurement can be read by a human observer.在一个根本仪器中，信号被传送到一个显示或记录设备中以便可以被观测者读出。The observed output is the measurement M. There are many types of display devices, ranging from simple scales and dial gage

36、s to sophisticated computer display systems. 察看结果是M。有很多类型的显示设备，从简单的天平和各类千分尺到复杂的电脑显示器。The signal can also be used directly by some larger system of which the instrument is a part. For example, the output signal of the sensor may be used as the input signal of a closed loop control system. 这个信号也可以经过一些

37、较大的系统的仪器零件直接运用。例如，传感器的输出信号可作为闭环控制系统的输入信号。If the signal output from the sensor is small, it is sometimes necessary to amplify the output shown in Fig.12.2. 假设从传感器输出的信号是小的，在Fig.12.2中放大输出量有时是必要的。 The amplified output can then be transmitted to the display device or recorded, depending on the particular

38、 measurement application. 然后放大输出可以传送给显示器或根据特定的测试程序记录。In many cases it is necessary for the instrument to provide a digital signal output so that it can interface with a computer-based data acquisition or communications system. 在很多情况下，仪器提供一个数字信号输出是很有必要的，这样它就可以与一个以计算机为根底的数据采集和通讯系统衔接。If the sensor does

39、 not inherently provide a digital output, then the analog output of the sensor is converted by an analog to digital converter (ADC) as shown in Fig.12.2. 假设传感器本身不能提供一个数字输出，那么传感器模拟输出将由一个模拟/数字转换器(ADC)转换，如图12.2所示The digital signal is typically sent to a computer processor that can display, store, or tr

40、ansmit the data as output to some other system, which will use the measurement. 数字信号通常发送给计算机处置器，以便可以显示、存储或传输数据作为其他系统输出，并可以运用丈量值。The null method is one possible mode of operation for a measuring instrument. A null instrument uses the null method for measurement. 对于丈量仪器零点法是一种合理的运作方式。零点调整仪采用零点法作为丈量方法。I

41、n this method, the instrument exerts an influence on the measured system so as to opposite in value, yielding a null measurement. 在该方法中，仪器对丈量系统产生了影响以便与值相反，发明出一个无效的丈量。Typically, this is accomplished by some type of feedback operation that allows the comparison of the measurand against a known standar

42、d value. 通常，由某种类型的反响操作运转，这种类型的反响操作允许被测变量与知规范值进展比较。Key features of a null instrument include: an iterative balancing operation using some type of comparator, either a manual or automatic feedback used to achieve balance, and a null deflection at parity shown in Fig.12.3. 零点调整仪的主要特点包括：运用某种比测仪的反复平衡操作，手

43、动或是自动的反响用以实现平衡，和零偏斜。在图12.3中同等显示。A null instrument offers certain intrinsic advantages over other modes of operation (e.g., see deflection instruments). 在零点调整仪中提供一定的内在优点优于其他操作方式 (例如，偏摆仪器)。 By balancing the unknown input against a know standard input, the null method minimizes interaction between the

44、measuring system and the measurand. 经过平衡未知输入和一个知的规范的输入，零点法将丈量系统和被测变量之间的相互作用减到最小。As each input comes from a separate source, the significance of any measuring influence on measurand by the measurement process in reduced. 由于每个输入一个独立的来源，任何丈量的重要性经过丈量过程降低对被测变量的影响。 In effect, the measured system sees a ve

45、ry high input impedance, thereby minimizing loading errors. 实践上，丈量系统看成一个非常高的的输入阻抗，从而减少负载误差。This is particularly effective when the measurand is a very small value. Hence, the null operation can achieve a high loading error. 当被测变量是一种非常小的值时这是非常有效的。因此，零操作可到达高负载误差。In practice, the null instrument will n

46、ot achieve perfect parity due to the usable resolution of the balance and detection methods, but this is limited only by the state of the art of the circuit or scheme being employed shown in Fig.12.4. 实践上，零点调整仪由于平衡和检测方法的有效的分辨率不能到达完全的相等，但这仅限制于电路目前的工艺程度或运用的方案图12.4所示。A disadvantage of null instruments

47、is that an iterative balancing operation requires more time to execute than simply measuring sensor input. Thus, this method might not offer the fastest measurement possible when high-speed of measurements are required. 零点调整仪的缺陷是与简单的丈量传感器输入相比迭代平衡操作需求更多时间去执行。因此，当要求快速丈量时该方法不能够提供最快的丈量。However, the user

48、 should weigh achievable accuracy against needed speed of measurement when considering operational modes. Further, the generally not the lowest cost measuring alternative. 然而，当思索到运作方式时，用户在丈量精度和所需求的丈量速度中进展权衡，进一步说，普通不以最低本钱丈量所选择。The deflection method is one possible mode of operation for a measuring in

49、strument. A deflection instrument uses the deflection method for measurement. 偏转法是丈量仪器的一种合理的运转方式。偏转量仪器是运用偏转法进展丈量。 A deflection instrument is influenced by the measurand so as to bring about a proportional response within the instrument. 偏转量仪器被被测变量影响以致于在仪器中导致相称的呼应。This response is an output reading t

50、hat is a deflection or a deviation from the initial condition of the instrument. 这种呼应是一个输出，读出的是从仪器的初始条件下的偏向或误差。 In a typical form, the measurand acts directly on a prime element or primary circuit so as to convert its information into a detectable form. 在一个典型的方式中，被测变量直接对主要要素或者初级回路起作用以便将信息转换成一个可检测的方式

51、。The name is derived from a common form of instrument where is a physical deflection of a prime element that is linked to an output scale, such as a pointer or other type of readout, which deflects to indicate the measured value. 这个名字源自一个常见的仪器，在主要元素物理偏向被衔接到一个输出，如一个指针或其他类型的读数，转向显示丈量值。The magnitude of

52、 the deflection of the prime element brings about a deflection in the output scale that is designed to be proportional in magnitude to the value of the measurand. 在输出的丈量中，主要元素的偏向大小产生偏向，被设计成与被测变量值的大小成比例。Deflection instruments are the most common of measuring instruments. 偏向仪器是最常见的是丈量仪器。 The relations

53、hip between the measurand and the prime element or measuring circuit can be a direct one, with no balancing mechanism or comparator circuits used. 被测变量和主要要素的关系或是丈量电路能够是直接的，不需求平衡机制或是运用的比较仪电路。The proportional response can be manipulated through signal conditioning methods between the prime element and

54、 the output scale so that the output reading is a direct indication of the measurand. 经过在主要元素和输出比例之间的信号调理方法，这个比例的呼应可以被人工操作，以致输出是被测变量的直接指示。Effective designs can achieve a high accuracy, yet sufficient accuracy for less demanding uses can be achieved at moderate costs. 有效的设计可以到达高精度，但在适当的本钱下对于低要求的运用可以到

55、达适当的精度。 An attractive feature of the deflection instrument is that it can be designed for either static or dynamic measurements or both. 偏向仪器的一个显著的特征是它可以设计为静态或动态丈量或两者兼而有之。 An Advantage to deflection design for dynamic measurements is in the high dynamic response that can be achieved. 动态丈量的偏向设计的优点是在高

56、动态呼应下可以实现。A disadvantage of deflection instruments is that by deriving its energy from the measurand, the act of measurement will influence the measurand and change the value of the variable being measured. 偏向仪器的缺陷是要从被测变量中获得他的能量，其丈量的方式影响被测变量并且改动被丈量变量值。This change is called a loading error. Hence, th

57、e user must ensure that the resulting error is acceptable. This usually involves a careful look at the instrument input impedance for the intended measurement. 这种变化是称为负载误差。因此，用户必需确保所产生的误差是可以接受的。为了预期的丈量，通常涉及到仪器输入阻抗的仔细思索。Computer-integrated manufacturing (CIM) is a philosophy for integrating hardware

58、and software in such a way as to achieve total automation. Computer-integrated manufacturing (CIM) 计算机集成制造 philosophy：哲学，哲理，理念；计算机集成制造(CIM)是经过软硬件集成实现整体自动化的一种理念。Although each company has its own idea of what CIM really means, most follow a pattern similar to that in Fig.8.1. 虽然不同的公司对CIM的含义有本人的了解，但大多数

59、认同类似于图8.1的模型。In this diagram, dedicated processing tasks are shown distributed around a factory.该图中给出了工厂中分布式的特定义务处置过程。 As computers are further removed form the actual manufacturing area, their function shifts from real-time control toward supervision.real-time control 实时控制supervision 监视，管理由于计算机与实践加

60、工制造区域有相当的间隔 ，故其功能由实时控制变为监控。It is generally agreed that at least three levels of computer integration are required for CIM to work: the cell level, the area level, and the plant level. the cell level:单元级 the area level：安装级 the plant level ：厂级通常以为CIM至少需求实现3级计算机集成，即单元级、安装级和厂级。Each level has certain tas