自动化专业英语 翻译

A feedback control system with proportional control is shown in Fig.6-4. In such a system a compromise is often necessary in selecting a proper gain so that the steady state error and maximum overshoot are within acceptable limits. Practically, however, a compromise cannot always be reached since an optimum value of may satisfy the steady state error but may cause excessive overshoot or even instability. This problem can be overcome if we employ proportional control in conjunction with some other type of control.一个反馈控制系统在Fig.6-4 用比例控制被显示。

在如此的一个系统中，一个妥协时常对选择一个适当的增益感到必需的，以便稳定状态错误和最大过度在可接受的限度里面。

实际地，然而，一个妥协不能够总是最适宜数值以来被到达可能使稳定状态错误满意但是可能引起过度的超越量或平坦的不稳定。

如果我们连同一些其他类型的控制使用比例控制，这一个问题能被克服。

A general feedback control system is shown in Fig.6-3. The output signal of the controller is the actuating signal that is employed for making necessary corrections so that the output corresponds to the input in some manner. The relationship of the actuating signal to the error signal is directly dependent upon 一个一般的反馈控制系统在Fig.6-3 被显示。

控制器的输出讯号是为了作必需的校正被使用的动作号志，以便输出以一些样子符合输入。

动作号志的关系对误差讯号直接地依赖，
A
performance
index is a quantitative measure of system performance. We must of course be clear as to what we mean by system performance. For example, do we mean that the error must be a minimum or constant? Or would we prefer to measure system performance by the square of the error? Clearly, the performance index will depend upon the specific criterion that we wish to invoke. It is therefore important that the design engineer must know a priori what he would like to optimize.一个表现索引是对制度表现的数量衡量。

我们一定当然很清楚关于我们根据系统表现意指的。

举例来说，我们意指错误一定是一个多数最小或常数吗？或我们会偏爱测量错误的角尺的系统表现吗？清楚地，表现索引将会取决于我们想要启动的特定的准则。

因此很重要的是，设计工程师一定知道先验的他想要最佳化的。

A signal flow diagram of a system is like a network consisting of junction points called nodes and directed line segments called branches. These nodes are connected by branches that have prescribed directions. A signal traveling along this branches does so only in the prescribed direction. Each branch has associated with it a gain or transmittance. The construction of a signal flow diagram involves the following of the cause and effect relations. Consider the flow diagram for C(s)=G(s)R(s) as shown in Fig.3-17. Generally, C(s), G(s), and R(s) are replaced by C, G, and R for brevity. The系统的一个讯号流程图像一个叫做波节的网络有接合器点而且指示线分呼叫支链。

这些波节被已经规定方向的支链连接。

讯号移动向前这支链如此只有在被规定的方向中做。

每个支链已经以它联合一个增益或透光度。

讯号流程图的构造包括因素的下列各项和效应关系。

为C （s）考虑流程图=如Fig.3-17 所显示的
G（s）半径（s）. 通常，C（s）、G
（s）和半径（s）为短暂被C 、G 和
半径代替。

这
Although control
systems having a single input an
output can be represented by a
single block diagram and one
transfer function, it is
advantageous to show the individual
elements since their transfer
functions may be generally
determined independently.虽然有一
个被输入的一个输出的控制系统能被
表现一个方框图和一个转移函数，但
是，表示通常的他们的转移函数以来个
别的元素可能独立地被决定是有利的。

Although the block
diagram representation is a very
convenient way of symbolizing a
control system, an alternate method
is the signal flow diagram or signal
flow graph. Once a signal flow
diagram of a control system is
constructed, the application of a
gain formula* yields the overall
transfer function. This
representation is also useful when
casting the system in state space
form as we shall see in the next
section. 虽然方框图表示法是象征一
个控制系统的非常方便方式，但是，一
个交互方法是讯号流程图或讯号流量
图表。

一经控制系统的一个讯号流程
图被装配，增益反应式的应用程序＊产
生全部的转移函数。

当我们将在下一
个断面中见到时，当以状态空间形状投
系统时，这表示法也是有用的。

Analyze the system
using any of the analytical or
graphical methods applicable to the
problem.（3) 分析使用任何分析或
图解式方法的系统适用于问题。

And it is noted that each term
in parentheses is equal to the
entire preceding term. This
property becomes useful in making
computations recursively on a
computer. The number of terms used
in approximating the transition
matrix is a function of the accuracy
desired and the speed of convergence.
If the transition matrix consists of
exponential elements with real
exponents, convergence may occur
quite rapidly.而且它被注意在刮弧的
每个期间和整个的前述期间相等。

这
性质在回归地在一部计算机上制造计
算方面变成有用。

在接近过渡基材方
面被用的期间的数目是被需要的准确
度的一个功能和收敛的速度。

如果过
渡基材和真正的指数有指数元素，收敛
可能相当，快速地发生。

Around the beginning of
the twentieth century much of the
work in control systems was being
done in the power generation and the
chemical processing industry. Also
by this time, concept of the
autopilot for airplanes was fairly
well developed.在二十世纪初，人们
在能源产生和化学处理工业中控制制
度中做了很多有关控制系统的工作。

也
在这时候，飞机的自动驾驶仪理论得到
更好的发展。

As an alternate way of system
representation in the last chapter
we also obtained a set of
first-order differential equations.
Later in this chapter we shall use
such a set to show how a control
system can be compactly represented
in matrix notation. Such a
representation is also called state
space representation and the
variables used are known as state
variables. We will show that such a
representation is directly related
to the governing first-order
differential equations as well as
the system transfer function. The
analysis of control systems using
the state space representation
constitutes what is referred to as
the modern method.当做一个系统表示
法的交互方法，在最后一个章节中，我
们也获得了一组一次,一阶微分方程。

稍后在这一个章节中，我们将使用如此
的一个组表示一个控制系统能如何在
基材记号中细密地被表现。

如此的一
个表示法也被认为状态是空间表示法，
而且被用的变数被知道例如状态变数。

我们将会表示如此的一个表示法直接
地被讲到控制一次,一阶微分方程和系
统转移函数。

使用状态空间表示法的
控制系统的分析组成什么被称为现代
的方法。

As an example of a control system
consider the simplifed version of
the attitude control of a spacecraft
illustrated in Fig. 1-4. We wish the
satellite to have some specific
attitude relative to an inertial
coordinate system. The actual
attitude is measured by an attitude
sensor on board the satellite. If
the desired and actual attitudes are
not the same, then the comparator
sends a signal to the valves which
open and cause gas jet firings.
These jet firings give the necessary
corrective signal to the satellite
dynamics thereby bringing it under
control. A control system
represented this way is said to be
represented by block diagrams. Such
a representation is helpful in the
partitioning of a large system into
subsystems and thereby allowing the
study of one subsystem at a time.
当做控制系统的一个例子考虑太空船
姿态控制的简化过的方框图如同1-4.
我们希望人造卫星能以特定的姿态运
行所以在内部应用了调节系统。

实际
的姿态被一个卫星表面的姿态探测器
测量。

如果期望的与实际的姿态不相
同，这时比较器将一个信号送到阀让阀
打开，并且使喷气点燃。

这些喷气火
焰藉此把必需的纠正信号给卫星动态
特性从而使卫星姿态受控制。

描述一
个控制系统可用方框图表示。

这样一
种描述方法在将一个大的系统分为一
些子系统时是很有帮助的，并使其能在
同一时间内研究子系统。

As an exercise (in convincing
yourself) you should form and take
its inverse Laplace transform and
see that it is equivalent to the
transition matrix shown in the
previous example.当做一种练习（在
使你自己信服方面），你应该造形而且
拿它的倒转Laplace转换而且见到它对
在早先的例中被显示的过渡基材是同
等物。

As another example consider
the system shown in Fig. 1-6. The
figure shows an illustration of the
conceptual design of a proposed Sun
Tracker. Briefly, it consists of an
astronomical telescope mount, two
silicon solar cells, an amplifier,
a motor, and gears. The solar cells
are attached to the polar axis of the
telescope so that if the pointing
direction is in error, more of the
sun’s image falls on one cell than
the other. This pair of cells, when
connected in parallel opposition,
appear as a current source and act
as a positional error sensing device.
A simple differential input
transistor amplifier can provide
sufficient gain so that the small
error signal produces an amplifier
output sufficient for running the
motor. This motor sets the rotation
rate of the polar axis of the
telescope mount to match the
apparent motion of the sun. This
system is depicted in block diagram
form in Fig. 1-7. The use of this
device is not only limited to an
astronomical telescope but to any
system where the Sun must be tracked.
For example, the output of a
photovoltaic array or solar
collector can be maximized using a
Sun Tracker.当做另外的一个例考虑在
图1-6 被显示的系统。

身材表示一个
被提议Sun 公司追踪者的概念上设
计的一个例证。

简短地，它有一个天
文学望远镜座，两个矽太阳能电池，一
个放大器、一个电动机和齿轮。

日光
电池被附上到望远镜的极轴，以便如果
磨利方向在错误中，较多的太阳的图像
落砂在一个电池上超过另一个。

这对
电池，当以平行的反相姿态连接，出现
当一个目前的来源而且担任位置错误
测知装置。

一个简单的微分输入电晶
体放大器能提供充份的增益，以便小误
差讯号生产为了运行电动机是充份的
一个放大器输出。

这一个电动机设定
望远镜座的极轴的转动率相配太阳的
虚表运动。

这一个系统在图1-7 以方
框图形状被描述。

这一个装置的使用
是不只有限制于一只天文学的望远镜
但是至Sun 公司一定被追踪的任何
系统。

举例来说，光电伏打行列的输
出或太阳的集极能使用一个Sun 公司
追踪者被最大值。

As our first example we will
solve for the motion of two
satellites connected by a tether.*
The arrangement consists of two
satellites connected by a massless
and inelasitic tether so that the
center of mass of the system moves
on a gived circular orbit.
Furthermore, the motion of the
satellites is planar, i.e.
restricted to the plane of the orbit.
当做我们的第一个例，我们将会为被一
个系绳连接的两个宇宙站的动作解决。

＊配置有被连接的两个宇宙站被一无
质量的和inelasitic 系绳以便系统的质
量中心继续一个被给的圆的轨道。

此
外，宇宙站的动作是平面，也就是限制
到轨道的平面。

As you progress further, it
is important that you realize that
the techniques developed in the
present chapter are not to be
considered as just another way of
obtaining a solution to problems
outlined in earlier chapters.
Instead these techniques are to be
interpreted as new tools useful for
not only observing variables inside
a control system, but handling a
very large number of input-output
combinations. As systems get more
complex (and interesting), we shall
be more dependent upon the computer
as a computational aid and
consequently rely more heavily on
states space techniques.因为你更进
一步进步，它很重要，你了解目前被发
展的技术章节是不当做获得对在较早
的章节中被概略说明的问题解决办法
的老套方式被考虑。

相反地这些技术
是当做是有用的新工具被解释对不只
有在一个控制系统内观察变数，但是处
理非常大量输入－输出的结合。

因为
系统变得更复杂的（和有趣的），我们
将更依赖计算机为一个计算的帮助而
且结果更很重仰赖状态空间技术。

Because control
systems occur so frequently in our
lives, their study is quite
important. Generally, a control
system is composed of several
subsystems connected in such a way
as to yield the proper cause-effect
relationship. Since the various
subsystems can be electrical,
mechanical, pneumatic, biological,
etc., the complete description of
the entire system requires the
understanding of fundamental
relationships in many different
disciplines. Fortunately, the
similarity in the dynamic behavior
of different physical systems makes
this task easier and more
interesting.因为控制系统在我们的
生活中时常出现，对他们的研究相当重
要。

通常，一个控制系统由被连接的
一些子系统以某种方式结合以便适应
因果关系。

因为各种不同的子系统可能
是微电子、机械、以及空气、生物学的，
等等.所以要描述一个完整的控制系统
需要了解其在不同学科之间的根本关
系。

幸运地，不同身体系统的动态特
性的相似性让这项工作变成更容易、有
趣。

Before analyzing a
control system it is necessary that
we have a mathematical model of the
system. The analysis of the
mathematical model gives us insight
into the behavior of the physical
system. Naturally, the accuracy of
the information obtained depends
upon how well the system has been
mathematically modeled.在分析是必
需的是，我们有系统的一个数学套式的
一个控制系统之前。

数学套式的分析
给我们对物性系统的行为的洞察。

自
然地，被获得的信息的准确度取决于系
统是多么的好算术地做模型。

Before continuing
further several observations are in
order. First, the i-jth element of
the transition matrix is zero if
there is no signal flow from the jth
node to the ith node . Second, the
term is the inverse Laplace
transform of the overall gain from
the jth node to the ith node. Finally,
if the signal flow diagram becomes
very complicated it may be desirable
to use Mason’s gain formula
discussed in Chapter 3. Although the
above method appears difficult
initially, its clarity and overall
simplicity cannot be overstated.
This method is particularly suited
for hand computation.在继续更进一
步一些的观测之前井然有序。

首先，
如果没有从jth 波节到ith 波节的讯
号流量，过渡基材的i－jth 元素是零。

其次，期间是从jth 波节到ith 波节的
总增益的倒转Laplace转换。

最后，
如果讯号流程图变成非常复杂，使用在
第 3 章被讨论的梅森的增益反应式可
能是令人想要的。

虽然上述的方法最
初显得很困难，但是，它的澄清度和全
部的单纯不能够被夸大的叙述。

这一
个方法特别地为手计算被适合。

Chapter 1 Introduction
Check the performance
(speed, accuracy, stability, or
other criterion) to see if the
specifications are met.（4) 检
查表现（速度、准确度、稳定性或其
他准则）看看是否规格被遇见。

Complementin
g the time domain analysis,
several graphical procedures are
presented in Chapter 7. It is
stressed that the utility of these
procedures is greatly enhanced if a
digital computer is used.求补时域
分析，一些图解式的程序在第7 章被
呈现. 一般强调，这些程序的公用程式
非常被提高，如果一个数传计算机被
用。

Consider the
electrohydraulic* vibration
isolation system shown in Fig.4-9.
The system essentially consists of
a rigid mass m vibrating as a result
of the excitation input y(t). The
mass m is connected to a hydraulic
actuator rod having a negligible
cross sectional area. By
considering the acceleration,
velocity, and relative displacement
of the rigid body as feedback
signals, we operate a servovalve to
control the flow of a relatively
incompressible fluid to and from the
hydraulic actuator. Derive the
equations of this system and discuss
the behavior of the system.在
Fig.4-9 考虑electrohydraulic ＊振动
离析制度被显示。

由于激发，系统本
质上有一个硬大众的m 振动输入y（t
标识）。

大众的m 被连接到有一个可
以忽略的十字形的剖面积的一个水力
的主动器棒。

藉由考虑刚体的加速度、
速度和相对位移为反馈作信号，我们操
作一个伺服阀控制流量一相对地不可
压缩流体来回地水力的主动器。

源自
这一个系统的反应式而且讨论系统的
行为。

Consider the transfer function of the system shown in Fig. 3-9a. The final transfer function is shown in Fig.
3-9d. Note that the first reduction involves a parallel combination; the second involves a cascade combination as well as the use of Eq. (3-6). The last reduction again involves the use of Eq. (3-6). And feeds this signal to the amplifier. The signal then goes to the d-c motor whose transfer function is G(s).The output, after being modified by the gear ratio N=N1/N2, is the feedback diagram. The block diagram is shown
in Fig. 3-11.考虑在图3-9 a 被显示
的系统的转移函数。

最后一个转移函
数在图3-9 d 被显示。

注意第一个还
原反应包括一个平行的结合；第二个
包括一个串级结合和情绪商数的使用。

（3-6). 最后一个还原反应再次包括情
绪商数的使用。

（3-6). 而且对放大器
的输送这讯号。

讯号然后去转移函数
是G（s）的直流杂音界限 c 电动机。

输出，在被gear ratio N＝N1/N2 修改
之后，是反馈线图。

方框图在图3-11
被显示。

Control system analysis is concerned with the study of the behavior of dynamic systems. The analysis relies upon the fundamentals of system theory where the governing differential equations assume a cause-effect relationship. A physical system may be represented as shown in Fig. 1-1. Where the excitation or input is x(t) and the response or output is y(t).
A simple control system is shown in Fig.1-2. Here the output is compared to the input signal, and the difference of these two signals becomes the excitation to the physical system, and we speak of the control system as having feedback. The analysis of a control system, such as described in Fig.1-2, involves the obtaining of y(t) given the input and the characteristics of the system. On the other hand, if the input and output are specified and we wish to design the system characteristics, then this is known as synthesis.控制系统的分析与动力
系统的行为研究有关。

分析依靠的系
统理论是自治微分方程因果关系。

一
个物理系统可能被表现如图所示. 激
发或输入是x（t标识）的地方和响应
或者输出是y（t标识）的地方. 一个简
单的控制系统在图1-2被显示。

输出在
这里比较对输入信号，并且这些的不同
两个信号成为物理系统的激励，我们说
这个控制系统有反馈。

控制系统的分
析如图所描述1-2, 包括被给这个系统
的输入和特性的获得y（t）。

另一方面，如果输入和输出被指定，而且我们想要
设计系统特性，这即是综合。

Control system specifications can be directly related to system response as shown
in Fig.6-1.This type of information
is germaine to second-order systems or higher-order systems which have
a pair of characteristic zeroes that are complex and dominate the transient behavior. For example, a system with characteristic zeroes at -5 ,-10±j2 and –0.5+j2 is a fifth-order system but the dominate zeroes are –0.5+j2. The commonly used terms to describe system specifications are peak overshoot, rise time, delay time, settling time, bandwidth, damping ratio and undamped natural frequency. The equations used for calculating these terms are given in Chapter 4 and a brief discussion follows.控
制系统规格能直接地被讲到如Fig.6-1
所显示的系统响应。

这类型的信息是germaine 至第二级的系统或者有复杂
的而且支配暂态行为的一对特性的零
的高次系统。

举例来说，一个系统在
-5,-10 用特性的零±j 2 和-0.5+j 2 是
除了一个第五的级系统这支配零是
-0.5+j 2. 普遍使用的期间描述系统定义是最高的超越量、上升时间，滞延时，
解决时间、带宽、阻尼比和无阻尼自然
频率。

被用的反应式为了计算这些期
间是被屈服的第 4 章和简短讨论追
从。

Derivative Control 引出的控制
Equations
representing the behavior of
electrical systems can be obtained
by the application of Kirchhoff’s
laws. They are: (1) the sum of the
voltage drops is equal to the sum of
the voltage rises in any given loop,
and (2) the sum of currents flowing
into a node equals the sum of
currents flowing out of the node.
The method employing the first law
is referred to as the loop method and
that employing the second is
referred to as the node method.
Either of the two methods are used,
in conjunction with the laws that
describe the physical nature of each
component in a system, to derive the
governing equations. 表现电气系统
的行为的反应式能依Kirchhoff 定律
的应用程序被获得。

他们是：（1) 压
降的总数和任何给定的回路电压上升
的总数相等，而且进入一个波节之内流
动的电流的总数相等流动出波节的电
流的总数（2)。

使用第一个定律的方法
被称为回路方法而且使用其次被称为
波节方法。

这两个方法之中任何一个
被用，连同描述一个系统的每个成分的
物性性质的定律，源自控制反应式。

Finally, optimize the
system parameters so that (1) is
satisfied.（5) 最后，将系统叁数最
佳化以便（1) 被满意。

Finally, the
refinement of the chip and related
computer development has created an
explosion in computational
capability and computer-controlled
devices. This has led to many
innovative methods in manufacturing
methods, such as computer-aided
design and manufacturing, and the
possibility of unprecedented
increases in industrial
productivity via the use of
computer-controlled machinery,
manipulators and robotics.最后，芯
片的精致和相关的计算机发展已经在
计算的能力和控制计算机的装置中建
立一个爆炸。

这已经在像计算机辅助
设计和制造业这样的制造业的方法中
导致许多创新的方法，和经由控制计算
机机械、操作者和机械手工程的使用的
工业生产力的空前增加的可能性。

For applications where it is
required to generate a signal which
is the sum of two signals we define
a summer or summing junction as
shown in Fig.3-3a. If the difference
is required, then we define a
subtractor as shown in Fig. 3-3b.
Subtractors are often called error
detecting devices since the output
signal is the difference between two
signals of which one is usually a
reference signal. Examples of
several components used for summing
and subtracting signals were given
in the previous chapter.因为它为产
生所需一个我们定义一个夏天的两个
讯号的总数的讯号的应用程序或总计
如Fig.3-3 所显示的接合器一。

如果
不同被需要，当时我们把一个消减器定
义为在图3-3 b 显示。

因为输出讯号
是哪一个通常是一个叁考讯号的在两
个讯号不同，消减器时常叫做发现装置
的错误。

被用的一些成分的例子为了
总计而且减去讯号是被屈服的早先章
节。

For complex poles the
response is oscillatory with the
magnitude varying exponentially
with time. Again, if the real part
is in the left half s-plane, the
magnitude decreases with time. If
the real part is positive, then the
magnitude increases exponentially
with time.对于复用竿支撑响应用指数
地以时间改变的量是振荡的。

再次，
如果真正的部分是在左者中一半的顺
式平面，量用时间的减少。

如果真正的
部分确定，当时量指数地以时间增加。

For real, simple poles the
time response is simply an
exponential which decays if the pole
is in the left half s-plane and
increases with time if the pole is
in the right half s-plane. The rate
of this decay or increase is
dependent upon the magnitude of pole.
Poles closer to the imaginary axis
are referred to as dominant poles
since the decay due to them takes
longer.为真正、简单的用竿支撑时间
响应只是一个衰退的指数如果极在左
一半的顺式平面中和增大用时间，如果
极在正直一半的顺式平面中。

这衰变
的率或增大依赖极的量。

极比较靠近
的到想像的桥被称为衰变以来由于他
们占优势的极拿更久。

Generate a
functional block diagram and obtain
a mathematical representation of
the system.（2) 产生一个功能的方框
图而且获得系统的一个数学上表示法。

Having represented
control systems using block
diagrams as well as state variables,
we turn our attention to system
response, i.e. how does a system
respond as a function of time when
subjected to various types of
stimuli? Here we are interested in
the system output without regard to
the behavior of variables inside the
control system. When this is the
case, we can work with the system
transfer function. If we desire C(s)
we can work with C(s)/R(s) and
specify R(s) and obtain the output.
On the other hand, if we need E(s)
we should work with E(s)/R(s) and
specify R(s). In any event it is
important to recognize that when the
response to a single input is
required without regard to the
behavior of variables inside a
control system, we speak of applying
the classical approach. This can be
most readily achieved by employing
techniques. This technique involves
representing the output (or desired
variable) as the ratio of two
polynomials and then expanding the
expression in partial fractions.
The constants of the partial
fraction are calculated by the
residue theorem. The output in the
time domain is the obtained by
taking the inverse Laplace
transform. A detailed discussion of
Laplace transforms is given in
Appendix A and should be reviewed by
those that do not have a good working
knowledge in the use of Laplace
transforms.有表现使用方框图和状态
变数的控制系统，我们将我们的注意转
向系统响应，也就是如何一个系统回应
随着时间推移当对刺激的各种不同类
型服从？在这里我们在控制系统内不
顾变数的行为对系统输出感兴趣。

当
这是外壳，我们能与系统转移函数合
作。

如果我们需要我们能与C（s）/
半径（s）合作而且叙述半径（s）而
且获得输出的C（s）。

另一方面，如
果我们需要我们应该与E（s）/半径（s）
合作而且叙述半径（s）的E（s）。

无
论如何，认识很重要，当响应在一个控
制系统内对一个输入被在不顾变数的
行为下需要时，我们说到加古典的方
法。

这能不迟疑地最藉由使用技术被
达成。

这技术包括表现输出（或者需
要了变数）为两多项式的比率然后在部
分分数中扩大展示语句。

部分分数的
常数被残余物定理计算。

在时域的输
出是这藉由拿倒转的Laplace转换获
得。

Laplace转换的详细讨论被屈服输
气管 A 而且应该被没有Laplace转换
的使用的一个好应用知识的那些检讨。

If a force f(t) is applied to a
linear spring (sometimes called a
Hookean spring), then from Hooke’s
law, f(t)=kx(t). a damper is the
element that creates the frictional
force. In general, the frictional
force in moving bodies consists of
static friction (striction),
coulomb friction, and viscous or
linear friction. We shall concern
ourselves only with linear friction.
When a force f(t) is applied to a
linear damper, then f(x)=Bdx(t)/dt.
Consider the mechanical system
shown in Fig. 2-8a and its
equivalent shown in Fig. 2-8b. If
initially the system is assumed to
be under static equilibrium and the
mass m is then perturbed, a free body
diagram showing all the forces is
drawn as shown in Fig. 2-8c.如果一
个力f（t标识）被应用到一个线性的弹
簧（有时被称为一个Hookean 弹簧）,
当时从虎克定律，f（t标识）=kx（t
标识）. 一个阻尼器是产生磨擦力的元
素。

大体上，磨擦力在移动物体方面
有静态摩擦（striction）, 库仑摩擦、
和黏着性或线性的摩擦。

我们将只用
线性的摩擦与我们自己有关。

当一个
力f（t标识）被应用到一个线性的阻尼
器，当时f（x）=Bdx（t标识）/dt。

考
虑力学的被显示在图2-8 a 的系统和
被显示在图2-8 b 的它的同等物。

如
果最初系统被假定在静态的平衡之下，
而且大众的m 然后被扰乱，一个表现
所有的军队的免费的物体线图被画如
图2-8 c 所示。

If we had represented the system of
Example 2-3 by a set of first-order
differential equations we 假如我们
表现例2-3 的系统一组一次,一阶微分
方程我们
If we have many inputs and
outputs that are monitored and
controlled, the block diagram
appears as illustrated in Fig. 1-5.
Systems where several variables are
monitored and controlled are called
multivariable systems. Examples of
multivariable systems are found in
chemical processing, guidance and
control of vehicles, the national
economy, urban housing growth
patterns, the postal service, and a
host of other social and urban
problems.如果我们有多个输入和输出
被监测和控制，方框图如图所示，方框
图在图1-5 出现如列举的。

一些变数
被监测而且控制的系统叫做多变数系
统。

多变数系统的例子在车辆的化学
的处理、引导和控制，国家的经济中被
发现，都市的壳成长图案、邮政的服务
和许多其他社会、都市的问题。

In general, the input
excitation to a control system is
not known ahead of time. However,
for purposes of analysis it is
necessary that we assume some simple
types of excitation and obtain
system response to at least these
types of signals. In general, there
are three types* of excitations used
in obtaining the response of linear
feedback control systems. They are
the step input, ramp input, and the
parabolic input. These are typical
test or reference inputs. In
practice, the input is generally
never exactly specifiable.大体上，
输入激发在时间之前对一个控制系统
不被知道。

然而，为是必需的是，我
们承担激发的一些简单类型而且获得
系统响应至至少讯号的这些类型的分
析的目的。

大体上，有三类型＊在获
得线性反馈控制系统的响应方面被用
的激发。

他们是步进输入，斜坡输入，
和抛物线的输入。

这些是典型的测试
或叁考输入。

在习惯中，输入从不通
常完全可指明。

In recent years the concepts
and techniques in control system
theory have found increasing
application in areas such as
economic analysis, forecasting and
management problems. An interesting
example of a multivariable system
applied to a corporation is shown in
Fig. 1-8. The inputs of Finance,
Engineering, and Management when
compared to the output which include
products, services, profits, etc.,
yield the excitation variables of
available capital, labor, raw
materials and technology to the
plant. There are two feedback paths,
one provided by the company and the
other by the marketplace.近几年来，
观念和控制系统理论中的技术在面积，
像是经济效益分析发现逐渐增加的应
用程序，预测和管理问题。

被应用到
公司的多变数系统的一个有趣例在图
1-8 被显示。

财务、工程学和管理的输
入当比较对含产品、服务、利润，等等
的输出，产生有效首都、人工、原料和
技术的激发变数到厂。

有两个反馈路
径，一由公司提供和藉着市场的其他
者。

In studying the system
response of a feedback control
system there are three things we
wish to know, viz. the transient
response, the steady state or forced
response, and the stability of the
system. The transient solution
yields information on how much the
system deviates from the input and
the time necessary for the system
response to settle to within certain
limits. The steady state or forced
response gives an indication of the
accuracy of the system. Whenever the
steady state output does not agree
with the input, the system is said
to have a steady state error. By
stability we mean that the output
does not get uncontrollably large.
在学习有三件事物，我们想要知道的反
馈控制系统的系统响应，viz 方面。

暂
态响应、稳定状态或被迫的响应和系统
的稳定性。

短暂的溶液产生关于系统
脱离多少输入和时间的资讯必需的让
系统响应对特定的限度之内安顿。

稳
定状态或被迫的响应提供系统的准确
度的一个指示。

每当稳定状态输出不
同意输入，系统据说有一个稳定状态错
误。

被稳定性，我们意指输出不变得
无法控制大。

In summary, we observe that
for cascaded elements the overall
transfer function is equal to the
product of the transfer function of
each element, whereas the overall
transfer function for parallel
elements is equal to the sum of the
individual transfer function.在摘
要中，我们观察为成瀑布落下的元素全
部的转移函数和每个元素的转移函数
的产品相等，然而给平行的元素全部的
转移函数和个别转移函数的总数相等。

In the previous chapter we saw
how a system may be represented by
linear ordinary differential
equations with constant
coefficients. By defining a single
input and single output in Laplace
transform notation, we managed to
obtain the transfer function of the
system under consideration. We
shall now begin with the transfer
function of individual components
and show how they can be combined in
a systematic way to obtain the
transfer function of the entire
control system. The analysis of this
overall transfer function
constitutes the classical method.
在早先的章节中，我们看见一个系统可
能如何被线性的普通微分方程用固定
的系数表现。

藉由在Laplace转换记
号定义一个输入和单一输出，我们设法
获得系统的转移函数在考虑中。

我们
现在将由他们能以有系统的方式被联
合获得整个控制系统的转移函数的个
别成分和表演的转移函数开始。

这个
全部转移函数的分析组成古典的方法。

Integral Control积分控制
It is important to remember that
all real control systems are
nonlinear; however, many can be
approximated within a useful though
limited range as linear systems.
Generally, this is an acceptable
first approximation. A very
important benefit to be derived by
assuming linearity is that the。