【正文】 approximately proportional to the product of the field density and the current ,some nonlinearity being introduced by the distortion of the stator field due to the flux generated by the armature current .This socalled “armature reaction” is kept small by carefully motor design .更確切的說,轉(zhuǎn)矩接近正比于場強(qiáng)與電流的乘積。然而一個復(fù)雜的過程控制系統(tǒng)可能包含好幾個被稱作伺服機(jī)構(gòu)的裝置。I: 9：It is usually possible to vary the set value in such a system by manual adjustment of a control knob or by means of an auxiliary automatic control 。而有種情況下，均假定負(fù)反饋網(wǎng)絡(luò)中的放大器是單向的。4：In practice ,a RTD may be used with as much as 500 feet of threeconductor cable without creating a perceptible error .實踐中，熱電阻探測器可使用至多500英尺的三導(dǎo)線電纜，而不會產(chǎn)生任一可察覺的誤差。//If one or more parameters ,or the very form of elemental equation ,vary in a known fashion with time ,the system is said to be timevarying .如果有一個或多個參數(shù)，甚至連基礎(chǔ)方程本身都以一種已知方式隨時間而變化，則此系統(tǒng)就稱為時變系統(tǒng)。//Continuoustime system are described by differential equation ,discretetime systems by difference ，而離散時間系統(tǒng)則用于差分方程描述。//First ,in many cases the implementation of the openloop control suggested above would require a very sophisticated (and hence expensive) puting device to determine the inputs required to counteract the predicted disturbance effects .首先，在許多情況下，實現(xiàn)上面所提到的開環(huán)控制需要一臺非常完善的（因而很費錢的）計算裝置，一邊用它算出抵消預(yù)估擾動影響所需的輸入量。//Most often this is in some kind of valve , but it might also be a belt or motor speed ,louver position ,and so on .最常見的是由某種閥來完成，但這也可能是一條皮帶，或者是馬達(dá)速度，口徑位置等等。//The input is in no way influenced by the output of the system ,represented by y(t) . 輸入變量絕不會受到y(tǒng)(t) 所表示的系統(tǒng)輸出變量的影響。F: 1： shows voltampere curves for a metal filament lamp ,V1(Ⅰ)，and for a carbonfilament lamp V2(Ⅰ)，(Ⅰ)和V2(Ⅰ)分別表示金屬絲燈泡和碳絲燈泡的伏安特性曲線，//As is seen , the relation between the voltage and the current in each lamp is other than linear . 如圖所示每個燈泡的電流和電壓之間的關(guān)系并不是線性的，//The resistance of the metalfilament lamp increases ,and that of the carbonfilament lamp decreases with increase of ，金屬絲燈泡的電阻是增加的，而碳絲燈泡的電阻是減少的。//Such motors are fairly mon ponents in systems of interest to control engineers . 這種電機(jī)是控制工程師在系統(tǒng)中應(yīng)用的比較普遍的元件。 6：A robot , once properly programmed ,will not put a chip in the wrong place .一旦適當(dāng)?shù)鼐幊?，機(jī)器人就不會將芯片發(fā)錯地方。4：An example is the speed control system of a turbinegenerator set in a power station ,whose main purpose is to maintain the generator speed as nearly constant as possible 。3：A new phase in robot applications has been opened with the development of “intelligent robot ” . 一個機(jī)器人應(yīng)用的新局面隨著“智能機(jī)器人”的發(fā)展而已近打開。//The handeye coordination for generalpurpose manipulation will be extremely powerful in the industrial world .這種用于通用的手眼配合操作在工業(yè)界將會變得極為有效力。2：Consider the armaturecontrolled .motor shown schematically in . 。D: 1：Denoting the mass moment of inertia of the armature as J ,and assuming that there is an externally applied load torque mL(t) and a viscous friction torque Cw(t) opposing the motion ,we may write 設(shè)電樞的轉(zhuǎn)動慣量為J，外加負(fù)載轉(zhuǎn)矩為mL (t) ,摩擦轉(zhuǎn)矩為Cw(t),兩者都是阻礙運動的，于是得E: 1：Every time the interface is used to read a transducer ,the same operations must be carried out to convert the input number into a more convenient ，同時還要將輸入數(shù)值轉(zhuǎn)換成更容易的形式。//The input or control u(t) is selected based on the goals for the system and all available a priori knowledge about the system .輸入變量或控制作用u（ t）是根據(jù)本系統(tǒng)的目標(biāo)以及所有可獲取的先驗知識而選定的。5：For every process there must be final actuator that regulates the supply of energy or material to the process and changes the measurement signal . 對每一過程，均必須由最終的控制器來調(diào)節(jié)過程中能量或材料的供給量，并且改變測量值。7：For negative feedback to exist ,either A or B must be a negative quantity to give the loop phase inversion , and the return difference is always (1+AB) for negative feedback .為了形成反饋，A或B必須為負(fù)量以使得環(huán)路形成倒向，因而對于負(fù)反饋深度恒等于（1+ab）.H: 1：However ,this advantage is more than outweighed by the disadvantages of openloop control and the inherent advantages of feedback systems . 然而，這一優(yōu)點比不上開環(huán)控制的缺點和反饋系統(tǒng)的固有優(yōu)點。//If ,as in sampling or digital systems ,some elemental equations are defined or used only at discrete points in time ,a discretetime system is the result . 而假如，在采樣問題或數(shù)字系統(tǒng)中常見這種情況，有些基礎(chǔ)方程僅定義于，或僅能應(yīng)用于離散的時間點上，這就導(dǎo)致了離散時間系統(tǒng)。//When all elemental equations can be described by a set of constant parameter values ,as in the familiar RLC circuit ,the system is said to be stationary or timeinvariant or constant coefficient .當(dāng)所有的基礎(chǔ)方程都能用一組定常參數(shù)值來描述，正如熟知的RLC電路的情況，就稱該系統(tǒng)是穩(wěn)態(tài)的，或時不變的，或常系數(shù)的。3：In each case ,the input circuit of the amplifier can be represented by an equivalent passive impendence Zi defined as the ratio of Vi/Ii or admittance Yi ,defined as Ii/vi. 在每種情況下，放大器的輸入回路都可以用一個等值無源阻抗Zi（Zi 是vi與Ii的比值）or 等值導(dǎo)納Yi（Yi是Ii與Vi比值）來表示。7：It is assumed in each case that the forward