1、单词：20 分，10 个二。句子翻译： 40 分，8 题1: P2 A common method of analyzing an electrical network is mesh or loop analysis. The fundamentallaw that is applied in this method is Kirchhoffs first law, which states that the algebraic sun of thevoltages around a closed loop is 0 ,or , in any closed loop , the sum of
2、 the voltage rises must equal the sum of the voltage drops. Mesh analysis consists of assuming that currentstermed loop currentsflow in each loop of a network ,algebraically summing the voltage drops around each loop ,and setting each sum equal to 0.分析电网络的一般方法是网孔分析法或回路分析法。应用于此方法的基本定律是基尔霍夫第一定律，基尔霍夫第一
3、定律指出：一个闭合回路中的电压代数和为 0，换句话说，任一闭合回路中的电压升等于电压降。网孔分析指的是：假设有一个电流即所谓的回路电流 流过电路中的每一个回 路，求每一个回路电压降的代数和，并令其为零。2: P17Alternatively, suppose that there had been attached to each pilots seat an electronic device that provided an output voltage which is V1 when the seat is occupied and V2 when the seat is not oc
4、cupied. Let us attach the designation “true” to the voltage level V2 so that the level V1 is “false”. Let us further construct an electric circuit with two sets of input terminals and one set of output terminals. The circuit is to have the property that the output voltage will be V2 if and only if b
5、oth inputs, i.e., one input AND simultaneously the other, are at the level V2. Otherwise the output is V1 Finally let us connect the inputs to the devices on the chairs of pilots A and B and arrange that an alarm bell, connected to the output Z, respond when the output is V2 (“true”) and not otherwi
6、se. We have then constructed a circuit which performs the AND operation and is capable of making the logical deduction that the plane is unpiloted when, indeed, both pilots leave the cockpit换句话说，假设每一位飞行员座位下面有一个电子装置，当座位上有人时，其输出电压为V1，当座位上无人时，其输出电压为 V2。现在我们用“真”来代表电压 V2，从而使电压 V1表示“假 ”。让我们进一步制作一个带有两个输入端和
7、一个输出端的电路，此电路的特性是：只要两个输入，即一个输入同时和另一个输入相与，结果为 V2 时，输出电压才是 V2。否则，输出是 V1。最后，让我们把输入和飞行员 A 和 B 座位下的装置联结起来，并安装一个与输出 Z 相连的警铃，当输出是 V2 (“真”)时响应，否则不响应。这样，我们已创建了一个执行与操作的电路，这个电路能完成当两个驾驶员确实都离开驾驶舱时飞机是无人驾驶的逻辑推断。3: P66Control theory itself has two categories:classical and modern. Classical control theory, which had
8、its start during World War II, can be characterized by the transfer function concept with analysis and design principally in the Laplace and frequency domains. Modern control theory has arisen with the advent of highspeed digital computers and can be characterized by the state variable concept with
9、emphasis on matrix algebra and with analysis and design principally in the time domain. As might be expected, each approach has its advantages and disadvantages as well as its proponents and detractors. 控制理论本身分成两个部分：经典和现代。经典控制理论始于二次大战以传递函数的概念为特征，分析和设计主要在拉普拉斯域和频域内进行。现代控制理论是随着高速数字计算机的出现而发展起来的。它以状态变量的概
10、念为特征，重点在于矩阵代数，分析和设计主要在时域。每种方法都有其优点和缺点，也各有其倡导者和反对者4:P67Openloop and closedloop controlsystems(see Fig. 21A1).An openloop system is one in which the control action is independent of the output.A closedloop system ,however,the input of the plant is somehow dependent on the actual output Since the outpu
11、t is fed back in a functional form determind by the nature of the feedback elements and then subtracted from the input,a closedloop system is often referred to as a negative feedback system or simply as afeedback system.开环和闭环系统（如图 2-1A-1）：开 环控制系统是控制行为与输出无关的系 统。而闭环系统，其被控对象的输入在某 种程度上依赖于实际的输出。因为输出以 由反馈
12、元件决定的一种函数形式反馈回来， 然后被输入减去。闭环系统通常是指负反 馈系统或简称为反馈系统。5： P83Actual system are also subjected to undesirable inputs, such as noise in command inputs and disturbances arising from changes in the plant parameters or changes in the environment in which the plant is operating. Noise inputs that enter the syste
13、m with the command input require filtering techniques to remove or suppress them without affecting the command input itself. We shall limit our discussion to disturbance inputs which enter the system at the plant rather than at the controller. 实际系统总是容易受到不希望的输入干扰，例如， 命令输入中的噪声以及由于参数改变在被控对象中产生的干扰或者被控对象
14、工作环境变化产生的干扰。随着命令输入进入系统的噪声输入需要滤波器进行驱除或者抑制并不对输入信号产生影响。 我们将限于讨论通过被控对象进行系统的噪声而不讨论通过控制器进入系统的噪声6: P887.Loci are symmetrical about the real axis since complex openloop poles and zeros occur in conjugate pairs. 轨迹关于实轴对称，因为复杂的开环极点和零点成对的出现8.Sections of the real axis to the left of an odd total number of openl
15、oop poles and zeros on this axis form part of the loci, because any trial point on such sections satisfies the angle condition. 实轴上某个区间右侧实轴上的开环零极点数之和为奇数时，这个区间形成根轨迹，因为这个区间上的任一点满足幅角判据。9. If the part of the real axis between two o.l. poles (o.l. zeros) belongs to the loci, there must be a point of brea
16、kaway from, or arrival at, the real axis. If no other poles and zeros are close by, the breakaway point will be halfway. 如果实轴在两个开环极点（开环零点）之间属于根轨迹，则在其中必定有突破点（汇合点）.如果附近没有极点或者零点，则突破点（汇合点）必定在（两个开环极点/开环零点）中间7: P97When the function has no pole or zero inside the right-half s plane, i.e. the function is mi
17、nimum phase, the Bode plots can be sketched rather rapidly with a knowledge of the four elementary factors that appear in the function.当该函数无零点和极点在 S 平面右半部时， 即系统为最小相位系统， 可以使用函数的四个快速地绘出伯德图8: P99Similarly, the gain margin equals 1 divided by the magnitude at the frequency where the phase angle is -180,
18、 the gain margin in dB, is therefore the distance of the magnitude below 0dB at this frequency, as shown in Fig. 2-4A-2.同样，增益裕量等于 1 除以相角为 180 时对应频率的幅值。因此，,以 dB 来表示，为如图 Fig. 2-4A-2.所示的频率处，幅值曲线与 0 分贝线的距离。9: P163ROM is usually for the permanent, non-volatile storage of an applications program. Many mic
19、rocomputers and microcontrollers are intended for high-volume applications and hence the economical manufacture of the device requires that the contents of the program memory be committed permanently during the manufacture of the chips. Clearly, this implies a rigorous approach to ROM code developme
20、nt since changes cannot be made after manufacture. This development process may involve emulation using a sophisticated development system with a hardware emulation capability as well as the use of powerful software tools. ROM 通常是用于永久的、非易失的应用程序存储。许多的微处理器或者微控制器是大批量生产的， 为了省钱， 要求程序在生产时就永久地固化在存储器中。显然，这就
21、意味着 ROM 代码的开发必须十分精确，因为一旦生产出来就无法更改。 这种开发过程包括使用一个复杂的开发系统， 该系统包括硬件仿真能力以及功能强大的软件工具。10:P180One way to accomplish this objective is by first measuring the temperature T(t), then comparing it to its desired value, and based on this comparison, deciding what to do to correct for any deviation. The flow of s
22、team can be used to correct for the deviation. This is, if the temperature is above its desired value, then the steam valve can be throttled back to cut the steam flow(energy) to the heat exchanger. If the temperature is below its desired value, then the steam valve could be opened some more to incr
23、ease the steam flow(energy) to the exchanger. All of these can be done manually by operator, and since the procedure is fairly straightforward, it should present no problem. However, since in most process plants there are hundreds of variables that must be maintained at some desired value, this corr
24、ection procedure would required a tremendous number of operator. Consequently, we would like to accomplish this control automatically. That is, we want to have instruments that control the variable without requiring intervention from the operator. This is what we mean by automatic process control. 完
25、成这个目标的一个方法是首先测量温度， 然后将其与期望值比较， 在比较的基础上再决定如何去做以消除偏差。蒸汽的流量可以用于消除偏差。即， 如果温度高于期望值，将蒸汽阀关小以削减进入热交换器的蒸汽（能量） 。如果温度低于期望值，则蒸汽阀门就会打开大一点以增加蒸汽流量（能量） 。 所有这些都可以由操作员手工完成，而且由于步骤很直观，不会有什么问题。然而。在大多数的生产过程中有数百的变量必须维持在期望值，这就要求有很多的操作员。因此，我们就希望采用自动控制来完成这些工作。即，我们要用仪表来控制这些变量而不需操作员干预。这就是过程的自动控制11:P252伴随着信息处理与通信技术的发展,能完成诸多服务功能
26、的楼宇自动化系统也应运而生。当我们正在走向下一个世纪的时候，一个主要的趋势是开发多样化的通讯技术，包括音频与视频信号的传送，多媒体系统的开发包含了这些特点。我们主要的工作集中在：提供高清晰度和立体图像传输的可视化服务；具有意识、辨识、理解和推理的智能化服务；携带方便的个人移动通讯服务。我们的目标是进一步将信息处理和通讯技术融合在一起。这将导致具有更高集成水平的智能建筑，如图 6-2B-1 所示。三。段落翻译：25 分，两题（现代控制理论状态控制 P108 与过程控制 P182）P108：The concept of state occupies a central position in mo
27、dern control theory. However, it appear in many other technical and non-technical context as well. In thermodynamics the equations of state are prominently used. Binary sequential networks are normally analyzed in term of their state. In everyday life, monthly financial statements are commonplace. T
28、he President state of the Union meesage is another familiar example.状态的概念在现代控制理论中占据中心位置。然而其也出现在其他技术和非技术领域。在热力学中状态方程的概念被突出地使用。二进制序列网络通常使用状态的术语进行分析。在日常生活中每月的也使用财政（财务）状况。美国总统的国情咨文也是一个熟悉的例子。In all of these examples the concept of state is essentially the same. It is a complete summary of the status of t
29、he system at a particular point in time. Knowledge of the state at some initial time t0 plus knowledge of the system inputs after t0, allows the determination of the state at a later time t1. As far as the state at t1 is concerned, it makes no difference how the initial state was attained. Thus the
30、state at t0 constitutes a complete history of the system behavior prior to t0, insofar as that history affects future behavior. Knowledge of the present state allows a sharp separation between the past and the future.在上述所有的例子中， “状态”的概念是基本相同的。 “状态”完全就是系统在某个特殊时刻的“状况”的一个总结。状态在某个时刻 t0 的值再加上 t0 时刻的输入的知识可
31、以确定以后时刻 t1 的状态。就 t1 时刻的状态而言，它与初始状态是如何实现的无关。因此， t0时刻的状态就构成了 t0 以前行为的历史，这个历史状态在一定程度上影响系统未来的行为。当前状态就将过去与未来作了一个截然的划分。At any fixed time the state of a system can be described by the values of a set of variables xi called state variables. One of the state variables of a thermodynamic system is temperature
32、 and its value can arrange over the continuum of real number. In a binary network state variable can take on only two discrete values, 0 or 1. Note that the state of your cheking account at the end of the month can be represented by single number, the balance. The state of the Union can be represent
33、ed by such things as gross national product, percent unemployment, the balance of trade deficit, ect. For the systems considered in this article the state variables may take on any scalar value, real or complex. That is . Although some systems require an infinite number of state variables, only syst
34、em ixCwhich can be described by a finite number n of state variables will be considered here. Then the state can be represented by an n component state vector It belongs to an 12Tnxxn- dimensional vector space defined over the field C.在任何一个固定的时刻，系统的状态可以用变量集合的值 xi 来描述，称为状态变量。热力学系统的一个状态变量是温度，其值是在一个实数连
35、续区间 R 变化。对于一个二进制网络状态变量可以仅仅有两个离散的值，0 和 1。你在月底帐目的平衡的状态可以用一个数来表示。国情咨文中的状态可以用国民生产总值、失业率、贸易赤字等来表示。对于本文所考虑的系统，状态变量可以用任何一个标量值（实数或复数）来表示。即 。虽然ixC有的系统需要用无穷多个状态变量来表示，但是在这里我们仅仅考虑有限个数目状态变量的系统。因此，状态可以表示为 n 个分量的状态向量 。状态向量属12Tnx于某个域 C 上的状态空间。For Continuous-time system, the state is defined for all time in some int
36、erval, for example, a continually varying temperature or voltage. Discrete-time system have their state defined only at discrete times, as with the monthly financial statement or the annual State of the Union message. Continuous-time and discrete-time systems can be discussed simultaneously by defin
37、ing the times of interest as T. For continuous-time system T consists of the set of times . In 01ktteither case the initial time could be and the final time could be in some circumstances. 对于连续时间系统，状态可以定义某个区间上的所有时间。例如，连续变化的温度或者电压。离散时间系统的状态只定义在离散时刻。例如，每月财务状况或者年度国情咨文。连续时间系统和离散时间系统可以通过定义时间域 T 来统一讨论。对于连
38、续时间系统，T由 的所有实数构成。对于离散时间系统，T 由 离散时刻集合构01,t01ktt成。在任何一种情形，有时，初始时刻可以为 ，最终时刻可以是 。The state vector x(t) is defined only for those . At any given t, it is simply an ordered 01,tset of n numbers. However, the character of a system could change with time, causing the number of required state variables (and
39、not just the values) to change. If the dimension of the state space varies with time, the notation could be used. It is assumed here that is the same n-tdimensional state space at all .T状态向量 x(t)仅仅是在 上有定义。对于任意给定的 t ，x(t)仅仅是一个有序的01,tn 个数的集合。然而系统的特性可以随时间变化，会引起系统状态变量个数（不是变量的值）的变化。如果状态空间的维数发生变化需要使用符号 。这
40、里假设这里 表示，t对于 系统的维数都是 n 维。tTB: Fundamentals of Process ControlAt this time it is necessary to define some terms used in the field of automatic process control. The first term is controlled variable. This is the variable that must be maintained or controlled at some desired value. In the preceding exa
41、mple, the process outlet temperature, T(t), is the controlled variable. The second term is set point, the desired value of controlled variable. The manipulated variable is the variable used to maintain the controlled variable at its set point. In the example, the flow of steam is the manipulated var
42、iable. Finally, any variable that can cause the controlled variable to deviate away from set point is defined as a disturbance or upset. In most process there re number of different disturbance. As an example, in the heat exchanger shown in Fig. 5-1A-2, possible disturbance are inlet process tempera
43、ture, Ti(t), the process flow q(t), the quality of the energy of steam, ambient conditions, process fluid composition, fouling, and so on. What is important here is to understand that in the process industries, most often it is because of this disturbance that automatic process control is needed. If
44、 there were no disturbance, design-operating conditions would prevail and there would be no necessity of continuously “policing” the process.此时，有必要定义一些自动过程控制的术语。第一个属于是被控变量。该变量是指那些要维持或者控制在期望值的变量。 ，在前面的例子中，过程出口的温度 T(t)就是被控变量。第二个术语是设定点，指被控变量的期望值。操纵变量是指用于将被控变量控制在期望值的变量。在前面的例子中，蒸汽的流量就是操纵变量。最后，所有会使被控变量偏离期
45、望值的变量就称为干扰或者扰动。在大多数的过程中，有多个不同的干扰。例如，在图 5-1A-2 所示的热交换器中，可能的干扰有，入口的过程温度 Ti(t)，过程流量 q(t)，蒸汽能量的质量，周围的条件过程流质的成分，堵塞等等。必须理解，正是因为干扰存在，才需要自动控制。如果没有干扰，所设计的工作点就一直保持，也就不需要连续地调节过程了。The following additional terms are also important. Open loop refers to the condition in which the controller is disconnected from th
46、e process. That is, the controller is not making decision of how to maintain the controlled variable at set point. Another instance in which open loop control exists is when the action (A) taken by controller does not affect the measurement (M). This is indeed a major flaw in the control system desi
47、gn. Close-loop control refers to the condition in which the controller is connected to the process, comparing the set point to the controlled variable and determining corrective action.下面附加的术语也是重要的。开环是指这样的条件：控制器不与被控过程相连接。即控制器不会为维持被控变量在设定值而作决断。开环控制的另一个例子是控制器的动作不会影响测量量。闭环是指这样的条件：控制器与被控过程相连接，将设定值与被控变量相
48、比较然后决定再决定相应的调节行为。Let us now say a few words about the signal used to provide communication between instruments of control system. There are three principal types of signals used in the process industry today. The pneumatic signal, or air pressure, ranges normally between 3 and 15 psig. Less often, s
49、ignal of signals of 6to 30 psig or 3 to 27 psig are used. The usual representation in piping and instrument diagrams(P&ID) for pneumatic signal is .The electrical, or electronic, signal range normally between 4 and 20 mA. Less often 10 to 50 mA, 1 to 5V or 0 to 10V are used. The usual representation in (P&ID) is . The third type of signal, which is becoming common is the digital, or discrete, signal( zeros and ones). The use of process-control system based on large-scale computer, minicomputer, or microcomp
