Types of Feedback Control Systems

by B. Kuo & F. Golnaraghi

 

Feedback control systems may be classified in a number of ways, depending upon the purpose of the classification. For instance, according to the method of analysis and design, control systems are classified as linear or nonlinear, and time-varying or time-invariant. According to the types of signal found in the system, reference is often made to continuous-data or discrete-data systems, and modulated or unmodulated systems. Control systems are often classified according to the main purpose of the system. For instance, a position-control system and a velocity-control system control the output variables just as the names imply. In a particular case, the type of control system is defined according to the form of the open-loop transfer function. In general, there are many other ways of identifying control systems according to some special features of the system. It is important to know some of the more common ways of classifying control systems before embarking on the analysis and design of these systems.

 

Kuo, B., Golnaraghi, F. Automatic Control Systems. – 9^th Ed. – Wiley, 2010. – 944 p. (P. 11).

 

18. Make a sentence out of the two parts:

 

1)      Feedback -

 

2)      Driver -  

 

3)       Transducer -

 

 

a) a defect in a circuit, which prevents the current from following the intended course.

b) an electromagnetic device controlling a larger current or activating other devices in the same or another electric circuit.

c) an instrument for measuring, comparing or controlling electric voltage.

 

4)       Potentiometer

 

5)        Relay –

 

6)      Detector -

 

7)      Amplifier -

 

 

8)      Regulator –

 

9)      Fault -

 

10)     Assembly -  

 

d) a device used to increase the strength of an electric signal.

e) any machine part that communicates motion to another part.

f) any device that transmits energy from one system to another or converts the energy in form.

g) a mechanism for controlling the movement of machinery, the flow of liquids, gases, electricity, steam, etc.

h) an apparatus for indicating the presence of smth., as electric waves.

i) a fitting together of parts to make the whole.

 

j) a transfer of [part of the output of an active circuit or device back to the input.

 

UNIT THREE

 

Texts: History of the word “cybernetics”; The History of Cybernetics; Cybernetics; The Heritage and Revival of Cybernetics; Сфера кибернетики; Обратнаясвязь

Grammar: The Complex Subject and the Complex Object; the Construction for + infinitive

 

1.                Memorize the words:

Rudder – руль

to assure  – убеждать; уверять; обеспечивать; гарантировать

root – корень

to denote – обозначать, означать

to manage – управлять

 

2.                Translate the text and tell what the word “cybernetics” stands for:

 

History of the word "cybernetics"

 

Cybernetics is the discipline that studies communication and control in living beings and the machines built by man. A more philosophical definition, suggested by Louis Couffignal in 1958, considers cybernetics as "the art of assuring efficiency of action". The word cybernetics was reinvented by Norbert Wiener in 1948 from the Greek kubernetes, pilot, or rudder. The word was first used by Plato in the sense of "the art of steering" or "the art of government ". Ampère used the word cybernetics to denote "the study of ways of governing." One of the very first cybernetics mechanisms to control the speed of the steam engine, invented by James Watt and Matthew Boulton in 1788, was called a governor, or a ball regulator. Cybernetics has in fact the same root as government: the art of managing and directing highly complex systems.

 

3. Memorize the words:

a cone shaped float – конусообразный поплавок

to run dry – работать всухую

self-regulatory device – саморегулирующееся устройство

knowledge management – управление знаниями

to keep great minds busy – занимать умы великий людей

a holding tank – бак-сборник

 

4. Translate the text and speak about the history of cybernetics: