A control system consists of systems or processes assembled to obtain a desired output with specified performance given an input. An example is an elevator control system, which rises to the desired floor with speed and accuracy for passenger comfort. Control systems are integral to modern society and are found in applications like rockets, shuttles, manufacturing, and vehicles. Control systems in the body regulate processes like blood sugar, heart rate during fight or flight, eye movement, and grasping. The objectives of control systems are remote control, input convenience, disturbance compensation, and stability. Closed loop systems provide greater accuracy than open loop by measuring output, comparing to input, and correcting for disturbances through feedback.

1. Control Systems
A. Saksena

2. Introduction
● A control system consists of systems or processes or plants assembled for
the purpose of obtaining a desired output with desired performance, given a
specified input.
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3. Example - Elevator Control
● For example, consider an elevator.When the fourth-floor button is pressed on
the first floor, the elevator rises to the fourth floor with a speed and floor
leveling accuracy designed for passenger comfort.
● Two major measures of performance are apparent: the transient response and the
steady-state error.
○ The push of the fourth-floor button is an input that represents our desired output.
○ The performance of the elevator can be seen from the elevator response.
○ In our example, passenger comfort and passenger patience are dependent upon
the transient response.
■ If this response is too fast, passenger comfort is sacrificed; if too slow, passenger
patience is sacrificed.
■ The steady-state error is another important performance specification since passenger
safety and convenience would be sacrificed if the elevator did not level properly.
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4. Applications of Control Systems
● Control systems are an integral part of modern society. Numerous
applications are all around, some examples are:
○ Rockets fire
○ Space shuttle lifts off to earth orbit
○ Splashing cooling water, a metallic part is automatically machined
○ Self-guided vehicle delivering material to workstations in an aerospace assembly
plant glides along the floor seeking its destination.
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5. Natural Control System
● Within our own bodies are numerous control systems, such as:
○ The pancreas, which regulates our blood sugar.
○ In time of “fight or flight,” our adrenaline increases along with our heart rate,
causing more oxygen to be delivered to our cells.
○ Our eyes follow a moving object to keep it in view
○ Our hands grasp the object and place it precisely at a predetermined location.
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6. Examples of Control Systems
● Drone Control:
○ https://www.youtube.com/watch?v=2BwUMk10WqI
● Elevator Control
○ https://www.youtube.com/watch?v=CvY-G2FTbGM
● Communication based train Control System
○ https://www.mobility.siemens.com/global/en/portfolio/rail/automation/automatic-
train-control/communications-based-train-control-system.html
● Moving Block Train Control System
○ https://www.youtube.com/watch?v=a52ZSCIAoRk
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7. Objectives of Control Systems
● Some of the reasons for control systems:
○ Remote control
○ Convenience of input form
○ Compensation for disturbances
○ Achieving stability
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8. Components of Control System
● Input or Reference
● Input transducer
● Error or Actuating Signals
● Amplifier
● Controller
● Process/ Plant
● Disturbance
● Summing Junction
● Output Actuators/ transducer
● Feedback Amplifier
● Output or Controlled variable
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9. Open Loop System
● The distinguishing characteristic of an open-loop system is that it cannot
compensate for any disturbances that add to the controller’s driving signal.
● Open-loop systems, then, do not correct for disturbances and are simply
commanded by the input.
● The disadvantages of open-loop systems, is its inability to correct for any
disturbances occurring in the system.
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10. Closed Loop System
● The closed-loop system compensates for disturbances by measuring the
output response, feeding that measurement back through a feedback path,
and comparing that response to the input at the summing junction.
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11. Closed Loop System
● Closed-loop systems, have the obvious advantage of greater accuracy than
open-loop systems. They are less sensitive to noise, disturbances, and
changes in the environment.
● On the other hand, closed-loop systems are more complex and expensive
than open-loop systems.
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12. Objectives of Control System
● Two main objectives of study of control system:- Analysis and Design
● Analysis is the process by which a system’s performance is determined.
● Design is the process by which a system’s performance is created or
changed.
● To satisfy either following parameters will be studied:
○ Transient Response - Output variation when input changes
○ Steady State Response - stability of the output
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13. Design Process
Step 1
Transform
Requirements
Into a Physical
System
Step 2
Create a
Schematic
Step 3
Draw a Functional
Block Diagram
Step 5
Solve Mathematical
Model and Analyse the
Design
Step 4
Develop a
Mathematical Model
and Block Diagram
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14. Case Study: Antenna Azimuth Control Systems
System Concept
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15. Case Study: Antenna Azimuth Control Systems
Detailed Layout
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16. Case Study: Antenna Azimuth Control Systems
Schematic Diagram
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17. Case Study: Antenna Azimuth Control Systems
Functional Block Diagram
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18. Case Study: Antenna Azimuth Control Systems
Response Analysis
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