電氣工程專業(yè)英語考試

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. 當(dāng)我們似乎更喜歡信號處置數(shù)學(xué)方法的整體客觀性，如今證明，為了得到更好的速度性

2、能和低本錢的處置，人工智能方法經(jīng)常是更好的選擇。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. 經(jīng)常當(dāng)算法由于缺乏適宜的數(shù)學(xué)表達(dá)式和足夠強大處置器去運轉(zhuǎn)算法而不能展開時，他們是獨一的處理方案。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，在現(xiàn)代儀器中的信號處置通常會運用許多不同的方法。這個闡明只是對各種方式特征的一個引見并被書寫出來以協(xié)助 選擇。

4、空間的限制阻止了各種方法的詳細(xì)引見。Traditionally the most popular method used to develop mapping models is that of mathematical modeling. 傳統(tǒng)上用于開發(fā)映射模型中最受歡迎的方法是數(shù)學(xué)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. 探求數(shù)學(xué)模型以提供課題最高程度了解和性能最準(zhǔn)確的表達(dá)。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. 數(shù)學(xué)模型主要的缺陷是迅速變得復(fù)雜，以致在丈量系統(tǒng)中這些模型運轉(zhuǎn)通常是不能實現(xiàn)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. 在這類，單一的或多個輸入信號的數(shù)據(jù)處置經(jīng)過親密運用數(shù)學(xué)描畫轉(zhuǎn)化為輸出方式。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. 這種關(guān)系被稱為所謂的算法。嚴(yán)厲關(guān)系約束，關(guān)系可以說是有條理的，也就是說，對于恣意給定輸入輸出將永遠(yuǎn)是一樣的。算法只提供一種詮釋。 This method of signal processing is the most highly developed method and is certainly one to aim for because it is devoid of ambiguity. 信號處置的方法是最高速開展

8、的方法，必然以毫無歧義為目的的。All will agree on how it will respond. It carries a comforting level of understanding and, thus, acceptance. 一切方法對如何呼應(yīng)獲得了一致意見。它能到達(dá)一個令人欣喜的了解程度，從而接受它。Algorithmic methods can be very accurate, traceable, and can be calibrated with relative ease and agreement. 計算方法可以是非常準(zhǔn)確的，可描畫的，并能較容易地調(diào)整并

9、達(dá)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. 他們是許多儀器系統(tǒng)的根底。在儀器中，他們運用的來源可追溯到的早期的計算機運用，首先，機械計算機器(19世紀(jì)后期到1930年)，然后到模擬電子設(shè)備(20世紀(jì)初到20世紀(jì)60年代)，一切這些都從大約1950年開場由于數(shù)字計算機的運用而被替代。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 表達(dá)；化身；詳細(xì)化mathematical equation 數(shù)學(xué)方程式 一切的這些處置方法可以簡單地看成是一個包含適當(dāng)?shù)募夹g(shù)設(shè)備的數(shù)學(xué)方程詳細(xì)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. 隨著時間過去，由于需求復(fù)雜性和性能要求的增長，所以在計算機器里對算法細(xì)節(jié)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. 當(dāng)模型推進(jìn)數(shù)學(xué)描畫方法和人類開展的界限，數(shù)學(xué)描畫最終到達(dá)定義極限。通常，適當(dāng)?shù)募?xì)節(jié)可以被構(gòu)造進(jìn)模型之前產(chǎn)生。算法是由于模型缺乏而產(chǎn)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. 隨著算法復(fù)雜度的增長，處置才干必需提高以堅持準(zhǔn)確和處置速度。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. 雖然在算法的開展和計算才干上得到提高，在許多領(lǐng)域算法的方法論最終遇到數(shù)學(xué)上和技術(shù)上的壁壘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. 研討方法由于缺乏適當(dāng)?shù)乃惴ɑ蛴捎诟弑惧X的計算不能得到最好地運用。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. 在儀器上，另外一個要素也出現(xiàn)。在信號傳輸上快速的詳細(xì)處置導(dǎo)致需求添加電氣帶寬要求。添加的施工本錢也最終到達(dá)技術(shù)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. 僥幸的是在很多情況下可以抑制這些約束限制的處理方案在人工智能的其他領(lǐng)域中開展 (如今稱為“工程上的人工智能)，作為數(shù)學(xué)和其他領(lǐng)域的新方式，如決策論。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. 主要來說，一個算法的關(guān)鍵的局限性是它方式主義過于苛刻的程度極大地影響了它處置精度的深度。Other methods have emerged that allow vaguely subjective, as opposed to tightly objective, processing to be applied to good effect. 其他方法表現(xiàn)出允許模糊的客觀，而不是嚴(yán)謹(jǐn)?shù)目陀^，運用效果良好。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漸獲得接受，以致于如今許多被日常運用，并受專門運用軟件和電子集成電路支持。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，許多項選擇擇被看做是獨立的方法。漸漸地，文獻(xiàn)顯示出成雙交融的趨勢。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. 在一個更廣泛的混合方式中運用依然遭到限制。經(jīng)過把他們放在一個相對的角度上，這個闡明試圖給出一些常見的人

21、工智能的處置方法的綜合評價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. 令人感興趣的是以為在動物實驗中自然界計算似乎不會大量運用的算法，但這里提供了在人工智能中廣泛運用的算法。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. 這里是調(diào)用的范例展現(xiàn)了這樣的閱歷，基于知識系統(tǒng)(KBS)的一些常用方法可以經(jīng)過運用不完好的方式描畫產(chǎn)生多種輸入到一個輸出映射。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驚人的有效方案去處理以前未處理的需求。他們往往比計算方法好或是用更少的計算才干就可執(zhí)行類似義務(wù)。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. 他們與多重輸入處置有關(guān)并運用于將經(jīng)過傳感器提供的數(shù)據(jù)構(gòu)成決策。每個情況經(jīng)過平衡計算量的運用和有效的處置進(jìn)展判別。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. 不利的一面是他們?nèi)狈Ψ绞?，因此能夠很難進(jìn)展調(diào)整和驗證。他們沒有充足的科學(xué)根底和堅實的正式運轉(zhuǎn)根底，不能隨便地以為是 “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. 他們往往很難被另一流派了解，由于他們的描畫并沒有充分的文件可證明或做任何商定公約所規(guī)定。隨著他們的原理廣泛改動，他們必需在廣泛運用之前被深化了解。 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. 對于一切這些不利要素,他們往往能提供“更多的性能以得到低本錢，從而越來越多地采用。 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. 運用的繼續(xù)晉級并不闡明算法成為過時，但如今儀器設(shè)計者有更多的可用途置工具。Unit 12 Simple Instrum

28、ent Model簡易的儀器模型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. 在處理丈量問題的過程中，一個丈量過程的概念模型經(jīng)常是很有用的。在丈量儀器模型簡單概括的情況下，本單

29、元引見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提出了一種簡易儀器的概念模型。物理過程在左邊的圖形中進(jìn)展丈量，被測變量以一種可觀測的物理變量X描畫。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，觀測變量X不需求一定是個被測變量，而是在一些知的方法中簡簡與被測變量相關(guān)。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，物體的質(zhì)量通常是經(jīng)過稱重來丈量，被測變量是物體但是實踐丈量變量卻是地球引力場作用于物體的向下的引力。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. 在圖.12.1中儀器模型的中心功能部件是傳感器，它的功能是將物理變量輸入轉(zhuǎn)換成信號變量輸出。 Signal variable have the property that they can be manipulated in a transmission system, such as an electrical or mechanical circuit. 在傳輸系統(tǒng)中信號變量具有可操作的特性，如

33、電子回路或機械電路。Because of this property, the signal variable can be transmitted to an output or recording device that can be remote from the sensor. 由于這個特性，信號變量可以被傳送到一個遠(yuǎn)離傳感器的輸出或記錄安裝。 In electrical circuits, voltage is a common signal variable. In mechanical systems, displacement or force are commonly use

34、d as signal variables. 在電路中，電壓是一種常見的可變信號。在機械系統(tǒng)、位移和力通常被用做信號變量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. 信號變量的其他例子展如今表12.1。從傳感器輸出的信號可以被顯示、記錄或者被用作為一個輸入信號傳輸?shù)揭恍┐我O(shè)備

35、或系統(tǒng)。 In a basic instrument, the signal is transmitted to a display or recording device where the measurement can be read by a human observer.在一個根本儀器中，信號被傳送到一個顯示或記錄設(shè)備中以便可以被觀測者讀出。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. 察看結(jié)果是M。有很多類型的顯示設(shè)備，從簡單的天平和各類千分尺到復(fù)雜的電腦顯示器。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. 這個信號也可以經(jīng)過一些

37、較大的系統(tǒng)的儀器零件直接運用。例如，傳感器的輸出信號可作為閉環(huán)控制系統(tǒng)的輸入信號。If the signal output from the sensor is small, it is sometimes necessary to amplify the output shown in Fig.12.2. 假設(shè)從傳感器輸出的信號是小的，在Fig.12.2中放大輸出量有時是必要的。 The amplified output can then be transmitted to the display device or recorded, depending on the particular

38、 measurement application. 然后放大輸出可以傳送給顯示器或根據(jù)特定的測試程序記錄。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. 在很多情況下，儀器提供一個數(shù)字信號輸出是很有必要的，這樣它就可以與一個以計算機為根底的數(shù)據(jù)采集和通訊系統(tǒng)銜接。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. 假設(shè)傳感器本身不能提供一個數(shù)字輸出，那么傳感器模擬輸出將由一個模擬/數(shù)字轉(zhuǎn)換器(ADC)轉(zhuǎn)換，如圖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. 數(shù)字信號通常發(fā)送給計算機處置器，以便可以顯示、存儲或傳輸數(shù)據(jù)作為其他系統(tǒng)輸出，并可以運用丈量值。The null method is one possible mode of operation for a measuring instrument. A null instrument uses the null method for measurement. 對于丈量儀器零點法是一種合理的運作方式。零點調(diào)整儀采用零點法作為丈量方法。I

41、n this method, the instrument exerts an influence on the measured system so as to opposite in value, yielding a null measurement. 在該方法中，儀器對丈量系統(tǒng)產(chǎn)生了影響以便與值相反，發(fā)明出一個無效的丈量。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，由某種類型的反響操作運轉(zhuǎn)，這種類型的反響操作允許被測變量與知規(guī)范值進(jìn)展比較。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. 零點調(diào)整儀的主要特點包括：運用某種比測儀的反復(fù)平衡操作，手

43、動或是自動的反響用以實現(xiàn)平衡，和零偏斜。在圖12.3中同等顯示。A null instrument offers certain intrinsic advantages over other modes of operation (e.g., see deflection instruments). 在零點調(diào)整儀中提供一定的內(nèi)在優(yōu)點優(yōu)于其他操作方式 (例如，偏擺儀器)。 By balancing the unknown input against a know standard input, the null method minimizes interaction between the

44、measuring system and the measurand. 經(jīng)過平衡未知輸入和一個知的規(guī)范的輸入，零點法將丈量系統(tǒng)和被測變量之間的相互作用減到最小。As each input comes from a separate source, the significance of any measuring influence on measurand by the measurement process in reduced. 由于每個輸入一個獨立的來源，任何丈量的重要性經(jīng)過丈量過程降低對被測變量的影響。 In effect, the measured system sees a ve

45、ry high input impedance, thereby minimizing loading errors. 實踐上，丈量系統(tǒng)看成一個非常高的的輸入阻抗，從而減少負(fù)載誤差。This is particularly effective when the measurand is a very small value. Hence, the null operation can achieve a high loading error. 當(dāng)被測變量是一種非常小的值時這是非常有效的。因此，零操作可到達(dá)高負(fù)載誤差。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. 實踐上，零點調(diào)整儀由于平衡和檢測方法的有效的分辨率不能到達(dá)完全的相等，但這僅限制于電路目前的工藝程度或運用的方案圖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. 零點調(diào)整儀的缺陷是與簡單的丈量傳感器輸入相比迭代平衡操作需求更多時間去執(zhí)行。因此，當(dāng)要求快速丈量時該方法不能夠提供最快的丈量。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，當(dāng)思索到運作方式時，用戶在丈量精度和所需求的丈量速度中進(jìn)展權(quán)衡，進(jìn)一步說，普通不以最低本錢丈量所選擇。The deflection method is one possible mode of operation for a measuring in

49、strument. A deflection instrument uses the deflection method for measurement. 偏轉(zhuǎn)法是丈量儀器的一種合理的運轉(zhuǎn)方式。偏轉(zhuǎn)量儀器是運用偏轉(zhuǎn)法進(jìn)展丈量。 A deflection instrument is influenced by the measurand so as to bring about a proportional response within the instrument. 偏轉(zhuǎn)量儀器被被測變量影響以致于在儀器中導(dǎo)致相稱的呼應(yīng)。This response is an output reading t

50、hat is a deflection or a deviation from the initial condition of the instrument. 這種呼應(yīng)是一個輸出，讀出的是從儀器的初始條件下的偏向或誤差。 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. 在一個典型的方式中，被測變量直接對主要要素或者初級回路起作用以便將信息轉(zhuǎn)換成一個可檢測的方式

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. 這個名字源自一個常見的儀器，在主要元素物理偏向被銜接到一個輸出，如一個指針或其他類型的讀數(shù)，轉(zhuǎn)向顯示丈量值。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. 在輸出的丈量中，主要元素的偏向大小產(chǎn)生偏向，被設(shè)計成與被測變量值的大小成比例。Deflection instruments are the most common of measuring instruments. 偏向儀器是最常見的是丈量儀器。 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. 被測變量和主要要素的關(guān)系或是丈量電路能夠是直接的，不需求平衡機制或是運用的比較儀電路。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. 經(jīng)過在主要元素和輸出比例之間的信號調(diào)理方法，這個比例的呼應(yīng)可以被人工操作，以致輸出是被測變量的直接指示。Effective designs can achieve a high accuracy, yet sufficient accuracy for less demanding uses can be achieved at moderate costs. 有效的設(shè)計可以到達(dá)高精度，但在適當(dāng)?shù)谋惧X下對于低要求的運用可以到

55、達(dá)適當(dāng)?shù)木取?An attractive feature of the deflection instrument is that it can be designed for either static or dynamic measurements or both. 偏向儀器的一個顯著的特征是它可以設(shè)計為靜態(tài)或動態(tài)丈量或兩者兼而有之。 An Advantage to deflection design for dynamic measurements is in the high dynamic response that can be achieved. 動態(tài)丈量的偏向設(shè)計的優(yōu)點是在高

56、動態(tài)呼應(yīng)下可以實現(xiàn)。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. 偏向儀器的缺陷是要從被測變量中獲得他的能量，其丈量的方式影響被測變量并且改動被丈量變量值。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. 這種變化是稱為負(fù)載誤差。因此，用戶必需確保所產(chǎn)生的誤差是可以接受的。為了預(yù)期的丈量，通常涉及到儀器輸入阻抗的仔細(xì)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) 計算機集成制造 philosophy：哲學(xué)，哲理，理念；計算機集成制造(CIM)是經(jīng)過軟硬件集成實現(xiàn)整體自動化的一種理念。Although each company has its own idea of what CIM really means, most follow a pattern similar to that in Fig.8.1. 雖然不同的公司對CIM的含義有本人的了解，但大多數(shù)

59、認(rèn)同類似于圖8.1的模型。In this diagram, dedicated processing tasks are shown distributed around a factory.該圖中給出了工廠中分布式的特定義務(wù)處置過程。 As computers are further removed form the actual manufacturing area, their function shifts from real-time control toward supervision.real-time control 實時控制supervision 監(jiān)視，管理由于計算機與實踐加

60、工制造區(qū)域有相當(dāng)?shù)拈g隔 ，故其功能由實時控制變?yōu)楸O(jiān)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:單元級 the area level：安裝級 the plant level ：廠級通常以為CIM至少需求實現(xiàn)3級計算機集成，即單元級、安裝級和廠級。Each level has certain tas