CHAPTER 1

INTRODUCTION TO CONTROL SYSTEM

Automatic control has played a vital role in the advance of engineering and science. In
addition to its extreme importance in space-vehicle systems, missile-guidance systems,
robotic systems, and the like, automatic control has become an important and integral
part of modern manufacturing and industrial processes. 

For example, automatic control is essential in the numerical control of machine tools in the manufacturing industries in the design of autopilot systems in the aerospace industries, and in the design of cars and trucks in the automobile industries. It is also essential in such industrial operations as controlling pressure, temperature, humidity, viscosity, and flow in the process industries.

Since advances in the theory and practice of automatic control provide the means for
attaining optimal performance of dynamic systems, improving productivity, relieving
the drudgery of many routine repetitive manual operations, and more, most engineers and scientists must now have a good understanding of this field.
 
ELEMENTS OF PROCESS CONTROL






 




Advantages of Automatic Control System

•Accuracy: 

They are more accurate than open loop system due to their complex construction. They are equally accurate and are not disturbed in the presence of non-linearities.

 

•Noise reduction ability:
Since they are composed of a feedback mechanism, so they clear out the errors between input and output signals, and hence remain unaffected to the external noise sources.

Disadvantages of Automatic Control System

•Construction: 

They are relatively more complex in construction and hence it adds up to the cost making it costlier than open loop system.

•Stability: 

It is less stable than open loop system but this disadvantage can be striked off since we can make the sensitivity of the system very small so as to make the system as stable as possible.