自动化专业英语教程(王宏文第2版)-英译汉.doc

PART 1电路和电子工程基础 A 电路1 In the case of a resistor, the voltage-current relationship is given by Ohms law, which states that the voltage across the resistor is equal to the current through the resistor multiplied by the value of the resistance.就电阻来说，电压电流的关系由欧姆定律决定。欧姆定律指出：电阻两端的电压等于电阻上流过的电流乘以电阻值。2It may be that the inductor voltage rather than the current is the variable of interest in the circuit.或许在电路中，人们感兴趣的变量是电感电压而不是电感电流。B 三相电路1 Viewed in this light, it will be found that the analysis of three-phase circuits is little more difficult than that of single-phase circuits. 这样看来，三相电路的分析比单相电路的分析难不了多少。2 At unity power factor，the power in a single-phase circuit is zero twice each cycle在功率因数为1时，单相电路里的功率值每个周波有两次为零。3 It should be noted that if the polarity of point A with respect to N ( ) is assumed for the positive half-cycle, then when used in the same phasor diagram should be drawn opposite to, or 180 out of phase with, .应该注意，如果把A点相对于N的极性（ ）定为正半周，那么 在用于同一相量图中时就应该画得同 相反，即相位差为180。A 运算放大器1 One problem with electronic devices corresponding to the generalized amplifiers is that the gains, AU or AI, depend upon internal properties of the two-port system.对应于像广义放大器这样的电子装置，一个问题就是增益 AU 或者AI ，它们取决于两输入端系统的内部特性。2 This is one of the key features of Op-Amp designthe action of the circuit on signals depends only upon the external elements which can be easily varied by the designer and which do not depend upon the detailed character of the Op-Amp itself.这是运算放大器设计的重要特征之一在信号作用下，电路的动作仅取决于能够容易被设计者改变的外部元件，而不取决于运算放大器本身的细节特性。B 晶体管1 Put very simply a semiconductor material is one which can be “doped” to produce a predominance of electrons or mobile negative charges (N-type); or “holes” or positive charges (P-type).简单地说，半导体是这样一种物质，它能够通过“掺杂”来产生多余的电子，又称自由电子（N型）；或者产生“空穴”，又称正电子（P型）。2 TO1 is the original transistor shapea cylindrical “can” with the three leads emerging in triangular pattern from the bottom. Looking at the base, the upper lead in the “triangle” is the base, the one to the right (marked by a color spot) the collector and the one to the left the emitter.TO1是最早的一种晶体管形状即一个带有三个引脚的圆柱体“外罩”，这三个引脚在底部形成三角状。首先要注意的是，“三角形”上面的引脚是基极，其右面的引脚（由一个彩色点标出）为集电极，其左面的引脚为发射极。 A 逻辑变量与触发器1 We shall now briefly discuss the relevance of such terminology, and in so doing we shall bring out the special aptness of the designations “true” and “false” to identify the possible values of a variable. 现在我们将简要地讨论一下这些术语之间的关联，并在此过程中阐明用标示“真”和“假”来识别一个变量的可能值的特殊用途。2 Just as other algebras deal with variables which have a numerical significance, Boolean algebra deals with propositions and is an effective tool for analyzing the relationships between propositions which allow only two mutually exclusive alternatives.和其他处理有数字意义的变量的代数一样，布尔代数处理的是命题，而且布尔代数对于分析仅有两个互反变量命题之间的关系是一种有效的工具。3 There is a generally prevailing attitude in digital systems to view logic 0 as a basic, undisturbed, unperturbed, quiescent state and to view the logic 1 state as the excited, active, effective state, i.e., the state arrived at “after something has happened.”在数字系统中，普遍的观点是把逻辑0看成一个基本的、无干扰的、稳定的、静止的状态，把逻辑1看成一个激励的、活跃的、有效的状态，也就是说，这种状态是发生在“某种操作动作之后”。B 二进制数字系统1 Such devices operate well in a two-state or binary system, using conduction and cutoff as the operating states, and as a result the binary number system is generally employed in internal operations in digital computers.将导通和关断作为工作状态，这样的装置可以在两态即二进制系统中运行，因此数字计算机中的内部操作一般采用二进制系统。2 Given the basic idea of a chain of positive and negative, or positive and zero, or zero and negative pulses as representing binary 1s and 0s, there are many possible codes in which the pulses might be transmitted.给出一串正脉冲和负脉冲，或正脉冲和零，或者零和负脉冲来表示二进制的1及0时，就会有许多这些脉冲可以传递的码。A 功率半导体器件1 Power diodes provide uncontrolled rectification of power and are used in applications such as electroplating, anodizing, battery charging, welding, power supplies (DCand AC), and variable-frequency drives.电力二极管提供不可控的整流电源，这些电源有很广的应用，如：电镀、电极氧化、电池充电、焊接、交直流电源和变频驱动。 2 A gate turn-off thyristor (GTO), as the name indicates, is basically a thyristor-type device that can be turned on by a small positive gate current pulse, but in addition，has the capability of being turned off by a negative gate current pulse门极可关断晶闸管，顾名思义，是一种晶闸管类型的器件。同其他晶闸管一样，它可以由一个小的正门极电流脉冲触发，但除此之外，它还能被负门极电流脉冲关断。3 Such a gate current pulse of very short duration and very large di/dt has small energy content and can be supplied by multiple MOSFETs in parallel with ultra-low leakage inductance in the drive circuit.这样一个持续时间非常短、di/dt非常大、能量又较小的门极电流脉冲可以由多个并联的MOSFET来提供，并且驱动电路中的漏感要特别低。 B 电力电子变换器1 The efficiency of the rectifiers is very high, typically in the vicinity of 98%, because device conduction loss is low and switching loss is practically negligible.由于器件开通时损耗低，且其开关损耗几乎可忽略不计，故该类整流器的效率很高，典型值约为98。2 A variable voltage source can be converted to a variable current source by connection a large inductance in series and controlling the voltage within a feedback current control loop.通过串联大电感，可变电压源可以在电流反馈控制回路的控制下转换为可变电流源。A 直流电机分类1 Each of these motors has different characteristics due to its basic circuit arrangement and physical properties.每种类型的电动机由于其基本电路的不同而具有不同的特征和物理特性。2 The only difference, in most cases, is that the generator acts as a voltage source while the motor functions as a mechanical power conversion device.很多情况下，二者的唯一区别在于发电机常作为电压源，而电动机常作为机械能转换装置。3 A decrease in field current reduces the strength of the electromagnetic field. When the field flux is decreased, the armature will rotate faster, due to reduced magnetic-field interaction.励磁电流的减小会使磁场减弱。当磁通减少时，转子会由于与减弱的磁场相互作用而加速旋转。B 直流传动的闭环控制1 Any positive speed error, caused by either an increase in the speed command or an increase in the load torque, produces a higher current reference Ia*.由速度给定或负载转矩的增加所引起的任何正的速度偏差，都会产生更大的参考电流值Ia*。2 The speed error is corrected at the maximum permissible armature current until the speed error becomes small and the current limiter comes out of saturation.在最大允许电枢I下纠正速度偏差，直到速度偏差减小且限流装置退出饱和状态。A 交流机1 Neglecting the effect of slots and space harmonics due to non-ideal winding distribution, it can be shown that a sinusoidal three-phase balanced power supply in the three-phase stator winding creates a synchronously rotating magnetic field.如果忽略槽和由于非理想分布的绕组产生的空间谐波的影响，可以证明，在三相定子绕组中能以三相对称电源建立一个同步旋转的旋转磁场。2 The rotor winding will be subjected to a sweeping magnetic field, and have inducing current in the short-circuited rotor.转子绕组切割磁场，就会在短路的转子中产生感应电流。 3 This is in contrast to a machine with a cylindrical rotor structure having a uniform air gap (such as an induction motor), defined as a nonsalient pole machine.与其(凸极式同步机)对应的另一种电机是有均匀气隙的圆柱体形转子结构的电机(与异步机相似)，定义为隐极式同步电机。4 For example, the stator-pole pair A-A is energized when the rotor pole-pair a-a approaches it to produce the torque by magnetic pull, but is de-energized when pole alignment occurs.例如，当转子极对a-a接近定子极对A-A时，定子极对A-A被通电，通过磁拉力产生转矩，当两个极对重合时，定子极对A-A断电。 B 感应电机传动装置1 However, as the frequency is increased, the machine airgap flux falls causing low developed torque capability.然而随着频率增加，电机的气隙磁通下降，导致产生的转矩降低。2 In a well-designed PWM drive, the commutation frequency should be increased as permitted by the devices so as to obtain a good balance between the increase of inverter loss and decrease of machine loss.在设计完善的PWM传动系统中，应在器件允许的条件下增加换相频率，以便在逆变器损耗的增加和电机损耗的降低之间找到一个合适的平衡点。A 电力系统 1 In cities and other areas where open lines create a safety hazard or are considered unattractive, insulated underground cables are used for distribution.在城市和其它地区，明线存在安全隐患或者被认为影响美观，所以使用绝缘地下电缆进行配电。2 Each utility that agrees to share gains an increased reserve capacity, use of larger, more efficient generators, and the ability to respond to local power failures by obtaining energy from a linking grid.同意共享的每个电力企业可以获得不断增加的储备功率，使用更大、效率更高的发电机，从电网中获取电能以应对局部电力故障。3 Inductance and capacitance react with a tendency to nullify one another.电感和电容的作用能相互抵消。B 电力系统自动化 1 Metering values such as demand and peak are saved within the meter to create historical information about the activity of the power system.测量值，如需求量和峰值，可以保存在仪表中，用于创建电力系统运行的历史信息。2 Substation integration refers to combining data from the IEDs local to a substation so that there is a single point of contact in the substation for all of the I&C data.变电站集成指的是将局部和整个变电站的IED数据进行组合，于是对于变电站内所有I&C数据，只有一个单联系点。 3 The communications industry uses the term client/server for a device that acts as a master, or client, retrieving data from some devices and then acts as a slave, or server, sending this data to other devices.通信行业对设备使用术语客户/服务器， 该设备作为主设备或客户从其它设备得到数据，然后作为从设备或服务器向其它设备发送数据。PART 2 控制理论 A 控制的世界 1 The reaction time of a human pilot is too slow to enable him or her to fly an aircraft with a lightly damped Dutch roll mode without a yaw damper system.飞行员的反应速度太慢，如果不附加阻尼偏航系统，飞行员就无法通过轻微阻尼的侧倾转向方式来驾驶飞机。2 Since the output is fed back in a functional form determined by the nature of the feedback elements and then subtracted from the input因为输出会以由反馈部件特性决定的函数形式反馈回来，然后从输入中减去B 传递函数和拉普拉斯变换1 The designer quickly becomes adept in relating changes in the Laplace domain to behavior in the time domain without actually having to solve the system equations.设计人员很快就会熟练地把拉普拉斯域的变化与时域状态联系起来，而不需真地解系统方程（时域）。A 稳定性和时域响应 1 The table is continued horizontally and vertically until only zeros are obtained.这张表向水平（向右）垂直（向下）方向延伸，直到得到的都是零为止。B 稳态 1 the principle of superposition holds, 叠加原理成立，2 , thus eliminating the velocity error, and by being introduced ahead of the point of entry of the disturbance into the system, eliminates the steady-state error resulting from a step in the disturbance.，这样通过在系统扰动进入点之前引入（积分环节），可消除由扰动输入中的阶跃（成分）导致的稳态误差。A 根轨迹 1 as any single parameter, such as a gain or time constant, is varied from zero to infinity.当任意单一参数，如增益或时间常数，从零变到无穷时。2 These effects increase in strength with decreasing distance.随着到原点距离的减小，它们的作用强度会增加。此处distance指零（极）点到原点的距离。3 Ignoring for the weaker effect of the added pole, which is often placed at 10 times the distance to the origin, the zero忽略常被置于10倍于零点到原点距离处的附加极点的微弱作用，零点B 频率相应方法：奈氏图1 The wind loading of a tracking radar antenna, for example, results from a mean velocity component that varies with time plus superimposed random gusts.例如，跟踪雷达天线的风力负载是由一个随时间变化的平均速度成分与叠加的随机阵风组成的。2 , it is only approximate and is subject to misinterpretation. 只是近似的而且容易判断错误。3 It is also the negative phase shift (i.e., clockwise rotation) of KZ(s)/P(s) which will make the curve pass through -1.它也是能使曲线通过-1点的KZ(s)/P(s)的负相位移动（即顺时针旋转）的角度。A 频率响应法：波特图 1 This is also true for the leads corresponding to the simple and quadratic lag below.对应于后面的一次和二次滞后的超前环节也是这样。2 To ensure a specified attenuation (reduction) of noise components in the input above a certain frequency should be below a certain level.为保证对输入中高于一定频率的噪声成分指定的衰减，（伯德图中M）应低于某一水平。B 非线性控制系统1 Instead, a number of techniques exist, each of limited purpose and limited applicability.有几种技术存在，但有各自限定的目的和限定的适用范围。2 , or due to overlap of the lands on a hydraulic control valve spool over the ports to the cylinder.，或由于液压控制阀柱上的挡圈与通向液压缸的出口的重叠。3 , an initial condition or input outside the limit cycle leads to an unstable transient growth while transients following a sufficiently small disturbance decay to zero.，当暂态响应跟随一个足够小的扰动向零衰减的时候，一个在极限环外的初始条件或输入会导致一种不稳定的暂态增长。A 现代控制理论简介 1 The transition from simple approximate models, which are easy to work with, to more realistic models produces two effects.从易于处理的简单近似模型到实际一些的模型的转换存在两方面问题。2 It provides an ideal formulation for computer implementation and is responsible for much of the progress in optimization theory.它（现代控制理论）为计算机实现提供了理想的公式化方法，并对最优化理论的发展起了重要作用。3 As far as the state at t1 is concerned, it makes no difference how the initial state was attained.就t1时刻的状态而言，它与初始状态是怎样实现的无关。4 Thus the state at t0 constitutes a complete history of the system behavior prior to t0, insofar as that history affects future behavior.因此，t0时刻的状态构成了t0以前系统活动状态的历史，这个历史状态在一定范围内影响（系统）未来的行为。B 状态方程1 In transfer function models these equations are transformed and variables are eliminated between them to find the relation between selected input and output variables.在传递函数模型中，这些方程经过（拉氏）变换，并消去中间变量，以求得选定的输入输出变量间的关系。2 The generalized coordinates and momenta of Hamiltonian and Lagrangian mechanics are, in fact, a set of state variables.事实上，哈密尔顿和拉格朗日力学的广义坐标和动量就是一组状态变量。A 可控性，可观性和稳定性1 Since complete state controllability does not necessarily mean complete control of the output, and vice versa, complete output controllability is separately defined in the same manner.因为状态完全能控性不一定意味着输出的完全可控，而且反之亦然，所以输出完全能控性以类似的方式单独定义。2 Only local asymptotic stability with respect to the established equilibrium state can be guaranteed for linear analyses.只有相对于（系统）建立的平衡状态的局域渐近稳定才能保证线性分析（可以应用）。B 最优控制系统1 Complete controllabillity in the mathematical sense is a necessary but not sufficient condition for the existence of an optimal control.在数学意义上，完全能控是最优控制存在的必要条件但非充分条件。2 mathematically that is. 数学上是如此的。3 With the exception of some linear plants, the variational approach of Pontryagins minimum principle leads to a nonlinear two-point boundary-value problem that must be solved by numerical methods.除去一些线性控制对象外，庞垂根最小原理的推论引出了一个必须用以数字表示的方法求解的问题。A 传统控制与智能控制1 The term “conventional (or traditional) control” is used here to refer to the theories and methods that were developed in the past decades to control dynamical systems, the behavior of which is primarily described by differential and difference equations.“传统控制”这个术语是指在过去的几十年里发展起来的用于控制以微分和差分方程表述的动态系统的理论和方法。2 Because intelligent control addresses more general control problems that also include the problems addressed by conventional control, it is rather difficult to come up with meaningful bench mark examples.由于智能控制解决了包含传统控制解决的问题在内的更多更广泛的问题，所以提出有代表性的例子相当困难。3 Note that the precise definition of “intelligence” has been eluding mankind for thousands of years.我们注意到“智能”的精确定义已经数千年不为人类所知了。B 人工神经网络 1 The number of hidden neurons must be determined so that the network performs its best, one of the methods used often is trial and error.必须确定隐含神经元的数量以使网络性能最优，一种常用的方法是试凑法。2 Neural networks are performing successfully where other methods do not, recognizing and matching complicated, vague, or incomplete patterns.神经网络在识别匹配复杂、含糊和不完整图案的问题上得到了成功的应用，而其他方法对此问题无能为力。PART 3 计算机控制技术 A 计算机的结构与功能1 how the instruction execution cycle is broken down into its various components.指令执行周期怎样分解成不同的部分。2 One way to achieve meaningful patterns is to divide up the bits into fields一种得到（指令）有效形式的方法是将（这些）位分成段3 The majority of computer tasks involve the ALU, but a great amount of data movement is required in order to make use of the ALU instructions. 计算机的大多数工作涉及到ALU(逻辑运算单元)，但为了使用ALU指令，需要传送大量的数据。B 计算机与网络基础1 Some INPUT DEVICES allow direct human/machine communication, while some first require data to be recorded on an input medium such as a magnetizable material.有些输入设备允许直接的人机对话，而有些输入设备则需要先将数据存储在诸如磁性材料等输入介质上。2 connected directly to (or ONLINE to) a computer online与“直接连接”的概念不同，前者是“联机”，此处是指工作站键盘与主机连在一起工作，后者是指“物理连接”。3 Similarly, at a local level within, say, a single building句中的say是“比如说”的意思。A 外部信号与设备的接口1 In this interface, there is a “tristate” buffer which when it is enabled will force the processor bus to have the same binary value as the external data lines.在这种接口中，有一个三态缓冲器，它能迫使处理器总线与外部数据线有相同的二进制值。2 Ui is then removed and a known negative constant reference voltage U is integrated which produces a ramp down.然后去掉Ui，对一个已知的负常数参考电压U积分以产生一个下降的斜坡。B 计算机的应用1 Computer simulation as a powerful analytic tool widely used in scientific research and engineering design demonstrates unrivalled advantages.作为一种广泛应用于科学研究和工程设计的有力分析工具，计算机仿真显示出无与伦比的优点。2 Data, diagrams, tables, etc. showing its shape, dimension, structure, fabrication and the material it is made from are input as the software requires.表示产品形状、尺寸、结构、组成和制造材料的数据、图形和表格等将按软件的需求输入。3 The solution to that problem was then based on asynchronous low-speed lines organized in either a star topology with a line dedicated to each terminal, or a tree topology with multidrop lines.此问题的解决基于异步低速的传输线，其结构可以是每台终端单配一线的星状拓扑结构，也可以是多分支线的树状拓扑结构。 A PLC概述 1 One can also implement a gateway by means of an OPC DX server, a SCADA application or a specific communication card such as the APPLICOM one.句中的OPC DX即OLE for Process Control Data Exchange. OLE (Object Linking and Embedding) 为对象的链接与嵌入，SCADA（Supervisory Control And Data Acquisition）为数据采集与监视控制系统。B PAC新一代工业控制系统, 可编程自动化控制的未来1 So the “twenty percenters” either lived without functionality not easily accomplished with a PLC or cobbled together a system that included a PLC for the control portion of the code and a PC for the more advanced functionality. 因此那些要开发“20%应用”的工程师们要么使用一个PLC，无法轻松实现系统所需的功能，要么采用既包含PLC又包含PC的混合系统，他们利用PLC来执行代码的控制部分，用PC来实现更高级的功能。2 Multi-domain functionality, At least 2 of logic, motion, PID control, drives, and process on a single platform.多功能性，在一个平台上有逻辑、运动、PID控制、驱动和处理中的至少两种以上功能。3 Single multi-discipline development platform incorporating common tagging and a single database for access to all parameters and functions.单一的多规程开发平台使用通用标签和单一的数据库来访问所有的参数和功能。4 These RTOSs provide the capability to control all aspects of the control system, from the I/O read and write rates to the priority of individual threads spawned on the controller. 这些RTOS能控制系统的各个层面，从I/O读写速率到控制器上各个线程的优先级。A 单片机基础1 The single-chip microcomputer is the culmination of both the development of the digital computer and the integrated circuit, arguably the two most significant inventions of the 20th century.单片机是数字计算机和集成电路发展中的一个顶峰，而这二者可以说是20世纪的两项最有意义的发明。2 on-chip ROM 译为“片内ROM”。B 了解数字