英语翻译1.8 Block Diagram ReductionThe discussion of Section 1.7 appears to imply that if the transfer function relating input r and output c in block diagram,such as Fig .1.1 is desired,a differential equation relating these two variables must b

英语翻译1.8 Block Diagram ReductionThe discussion of Section 1.7 appears to imply that if the transfer function relating input r and output c in block diagram,such as Fig .1.1 is desired,a differential equation relating these two variables must b
英语翻译
1.8 Block Diagram Reduction
The discussion of Section 1.7 appears to imply that if the transfer function relating input r and output c in block diagram,such as Fig .1.1 is desired,a differential equation relating these two variables must be obtained first.Fortunately ,this is not necessary.The transfer function can be derived instead by certain algebraic manipulations of those of the subsystems or blocks.Some examples will show this block diagram reduction technique and provide some useful results.
Example 1.8.3 The configuration in Fig.1.5(a),which includes a minor feedback loop,is very common in servomechanisms .Derivation of C/R by the approach of Example 1.8.2 would be laborious ,but become simple if the result in(1.33) is used.It is applied first to reduce the minor feedback loop C/M to a single block ,as shown in Fig.1.5(b).but (1.33) applies again to this new loop and now yields the closed-loop transfer function.
Example 1.8.4 In a tow-input system,the additional input D often represents a dis-turbance ,such as a supply pressure variation in the level control example in Section 1.3 .With the additional block L ,the diagram models the effect of the disturbance on the system.For linear systems the principle of superposition applies,and the total output is the sum of the outputs due to each input separately.Thus the out-put due to R is found as before,and while finding that due to D,R is put equal to zero.The rule of Example 1.8.2 applies when finding the response to D,but note that the product of G2.Note also that for R=0 the minus sign for the feedback at R can be moved to the summing junction for D.Inspection now yields.
Example 1.8.5 In fig.1.6 the two feedback loops interfere with each other.The rearrangements (a) and (b) are alternative first steps to make the result in (1.33) again applicable .Verify that neither changes the system,and that applying (1.33) twice to (a) or (b) yields the closed-loop transfer function.
1.9 Conclusion
In this chapter a general introduction has been given first,including physical discussion of some fundamental features of control system behavior.A level control example led to a common block diagram configuration.Laplace transforms led to the transfer function description of dynamic behavior,and block diagram reduction to the description of an interconnected system of blocks.The application of transfer functions and transforms and transforms to calculation of the response c(t) to an input r(t) and initial conditions has been demonstrated for cases where the roots of the denominator of the transform C(s) are real and distinct.This provides a framework and motivation for study of the next chapter,and a basis for detailed discussion of transient response in Chapter 3.It also allows for an introductory examination of some of the effects of feedback in the problems below.

英语翻译1.8 Block Diagram ReductionThe discussion of Section 1.7 appears to imply that if the transfer function relating input r and output c in block diagram,such as Fig .1.1 is desired,a differential equation relating these two variables must b
1.8方框图减少
1.7那些讨论的部分的看起来暗示如果叙述输入r 和方框图c产量的那些传递函数,例如无花果树.1.1被想要,叙述这两个变量的一个微分方程必须被首先获得.幸好,这不必要.传递函数可能因为子系统或者块的的某些代数学的操作被改为得到.一些例子将显示这种方框图减少技术并且提供一些有用的结果.
例子1.8.3 构造在1.5图(一),哪个包括一较小反馈电路,在伺服机构内普通.C/R的出处以例子的方法1.8.2 将是艰苦的,如果结果在(1.33)被使用,但是变得简单.如图1.5(b)中所示,它被首先申请把较小反馈电路C / M 降低到一个单个的块.但是(1.33)再次应用于这个新环并且现在产生关闭循环传送函数.
在一个拖输入系统过程中的例子1.8.4,另外的输入D 经常代表di turbance,例如在第1.3 部分的在电平调节例子方面的一个供应压力变化.由于另外的块L,图解塑造骚动对系统的影响.对线性系统来说重叠的原则实行,并且由于分别每次输入,总产量是输出的总数.因此由于R 产量被象以前一样,和在发现由于D,R被使相等调零时发现.例子1.8.2的规章使用什么时候发现给D的反应,但是注意到那G2的产品.注意到也适合负号适合反馈在R可能采取行动给D.检查的求和点的R 0 =现在产生.
在无花果树里的例子1.8.5.1.6这个两个反馈电路互相干扰.重新安排(一)和(b)选择使结果在(1.33)方面再次适用的前措施.证实两者都不改变系统和那使用的(1.33)两次成(A)或者(b)产生关闭循环传送函数.
1.9个结论
在这章里一个一般的介绍已经被首先给,包括控制系统性能的一些基本的特征的物理讨论.一个电平调节例子导致一个普通方框图构造.拉普拉斯变换导致动态反应的传递函数说明,以及对一个块的互连系统的说明的方框图减少.传递函数的应用和转换并且改变成反应c(t)的计算到一输入r (t),起始条件已经在改变C(s)的分母的根是真正和清楚的的地方被为情况证明.这提供下一章的研究,以及在第3章的为瞬态响应的详细的讨论的一个基础的一种框架和动力.它也在下面的问题里考虑到对一些反馈的影响的引导检查.

减少1.8框图
第1.7条的讨论似乎暗示如果传递函数的输入和输出有关c r框图,如无花果.1.1时,需要一个微分方程这两个变量有关必须取得第一。幸运的是,这是没有必要的。传递函数可以衍生所取代的某些代数操作系统或街区。一些例子来说明这框图还原工艺,并提供一些有用的成果。
在Fig.1.5 1.8.3配置实例(a),包括一个小的反馈回路,servomechanisms是很普通的病症。...

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减少1.8框图
第1.7条的讨论似乎暗示如果传递函数的输入和输出有关c r框图,如无花果.1.1时,需要一个微分方程这两个变量有关必须取得第一。幸运的是,这是没有必要的。传递函数可以衍生所取代的某些代数操作系统或街区。一些例子来说明这框图还原工艺,并提供一些有用的成果。
在Fig.1.5 1.8.3配置实例(a),包括一个小的反馈回路,servomechanisms是很普通的病症。C / R推导方法的例子1.8.2会辛苦,但如果结果变得简单(1.33)使用。这是第一次来减少未成年人应用反馈回路C /米到一个单一的整体,如图Fig.1.5(b)。但是(1.33)重新申请了这一新的环和现在的闭环传递函数的产量。

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