1. 0. Administrative Topics
EE3511: Automatic Control Systems
0. Administrative Topics
Dr. Ahmed Nassef
EE3511_L1
Salman Bin Abdulaziz University

2. Salman Bin Abdulaziz University
Textbook
Dorf and Bishop, Modern Control Systems 11th Ed. 2007
References :
Ogata K., Modern Control Engineering, 3rd Ed
Close, Frederick and Newell. Modeling and Analysis of Dynamic Systems, 3nd edition, John Wiley, 2002.
Norman S. Nice. Control Systems Engineering, John Wiley & Son, 4th Ed. 2003
EE3511_L1
Salman Bin Abdulaziz University

3. Salman Bin Abdulaziz University
Grading Policy
Exam 1 (20%),
Exam 2 (20%),
Final Exam (50%),
HWs + Quizzes (5%)
Attendance & class participation (5%), penalty for late attendance
Note: No absence, late homework submission allowed without genuine excuse.
EE3511_L1
Salman Bin Abdulaziz University

4. 1. Introduction to Control Systems
EE3511: Automatic Control Systems
1. Introduction to Control Systems
EE3511_L1
Salman Bin Abdulaziz University

5. Salman Bin Abdulaziz University
Why do we study control systems?
EE3511_L1
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6. What do these two have in common?
Both are highly nonlinear, complicated dynamics!
Both are capable of transporting goods and people over long distances
BUT
One is controlled, and the other is not.
Control is “the hidden technology that you meet every day”
It heavily relies on the notion of “feedback”
EE3511_L1
Salman Bin Abdulaziz University

7. Salman Bin Abdulaziz University
The Course Goal
Learn how to model, setup mathematical description, analyze and design linear control systems
EE3511_L1
Salman Bin Abdulaziz University

8. Course Objectives The students will learn to
model mechanical and electrical systems.
use Laplace transform to solve linear dynamical systems.
find transfer functions using signal flow graph
analyze the stability using Routh-Hurwitz method.
characterize transient and steady state response of linear systems.
EE3511_L1
Salman Bin Abdulaziz University

9. Course Objectives (cont.)
analyze and design linear control systems using Root locus
PID controller Design
analyze, design controllers and simulate dynamical systems using MATLAB and SIMULINK.
implement controllers for pilot scale processes.
In the Lab
EE3511_L1
Salman Bin Abdulaziz University

10. Salman Bin Abdulaziz University
Course Outlines
Introduction to Control Systems
Modeling of Dynamical Systems
Mechanical
Electrical
Laplace Transform
Review of complex variables
Laplace Transform, properties
Inverse Laplace Transform
Solution of Ordinary Differential Equations
Transfer functions
EE3511_L1
Salman Bin Abdulaziz University

11. Salman Bin Abdulaziz University
Course Outlines
Block Diagrams and Signal Flow Graphs
Block diagrams and manipulation
Signal Flow Graphs
Analysis of Control Systems
Test Signals: step, impulse, ramp , sinusoidal
Effect of feedback on transient response
Disturbance reduction
Effect of feedback on steady state error
EE3511_L1
Salman Bin Abdulaziz University

12. Salman Bin Abdulaziz University
Course Outlines
Time Response of Control Systems:
Time domain specifications in transient and steady state requirements
Response of first order systems
Response of second order systems
Response of higher order systems
Steady state analysis and error constants
EE3511_L1
Salman Bin Abdulaziz University

13. Salman Bin Abdulaziz University
Course Outlines
System Stability and Root locus:
Concept of stability
Routh-Hurwitz stability criteria
Stability of feedback control systems
Design Example
Introduction to root locus: concept and procedure.
EE3511_L1
Salman Bin Abdulaziz University

14. Salman Bin Abdulaziz University
Course Outlines
PID controller Design
Introduction to PID
Guidelines for PID design
Ziegler Nichols methods
EE3511_L1
Salman Bin Abdulaziz University

15. 2. Introduction to Control Systems
EE3511: Automatic Control Systems
2. Introduction to Control Systems
EE3511_L1
Salman Bin Abdulaziz University

16. Salman Bin Abdulaziz University
The Course Goal
To be able to model, setup mathematical description, analyze and design linear control systems
EE3511_L1
Salman Bin Abdulaziz University

17. Salman Bin Abdulaziz University
Systems
A system is any set of interrelated components acting together to achieve a common objective.
Each system has a process (Plant), inputs and outputs
inputs Process outputs
(Plant)
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18. Salman Bin Abdulaziz University
Example
You could think of a car as a “system". The inputs are the positions of the steering wheel, gear shift lever, gas, brake and clutch pedals. The output is the position of the car.
EE3511_L1
Salman Bin Abdulaziz University

19. Block Diagram Representation of Systems
inputs Process outputs
(system)
Inputs are signals that affect the system variables
Represented by arrows entering the system
Outputs are measured or calculated variables
Shown as arrows leaving the system
Process represent the relationship between inputs and outputs
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Salman Bin Abdulaziz University

20. Salman Bin Abdulaziz University
What is Control?
Control is a term that describes the process of forcing a system to behave in a desired way in order to achieve certain objective(s)/goal(s).
Control is the process of making a system variable adhere to a particular value, called the reference value.
EE3511_L1
Salman Bin Abdulaziz University

21. Salman Bin Abdulaziz University
Control Systems
A group of actions assembled in such a way to regulate some outputs at their desired levels.
used to increase productivity and improve performance of systems.
EE3511_L1
Salman Bin Abdulaziz University

22. Control Engineering Now
Control Engineering is becoming an important field
Engineers from different disciplines (Electrical Mechanical, Aerospace, Chemical,…) are learning about control engineering
Applications continue to grow and spread
Control Systems are important in modern societies. Examples of applications of control systems include Petrochemical plants, airplanes, cars, air-conditioning systems and weapons.
Biological systems using control systems. Our bodies maitain the body temperature at a specified temperature. The Glucose Level in our is being controlled. Without control walking will not be possible.
Techniques of control engineering have been used in many areas. It has been used to control inflation and unemployment rate.
EE3511_L1
Salman Bin Abdulaziz University

23. Control Systems in modern societies.
Control Systems Applications include
Petrochemical plants,
airoplanes,
cars,
air-conditioning systems
Weapons ….
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24. Salman Bin Abdulaziz University
Biological systems use control systems
Control body temperature
Control the Glucose Level
Control is used to help us walk, move, see, write, play,
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Salman Bin Abdulaziz University

25. Salman Bin Abdulaziz University
Techniques of control engineering have been used in many areas.
To control inflation
To control unemployment rate.
EE3511_L1
Salman Bin Abdulaziz University

26. Classification of control Systems
Open loop –Closed loop
Linear-Nonlinear
Continuous-Discrete
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27. Open loop Control Systems
An open loop control system consists of three basic components:
Control Element: Determines the action needed for the given input
Correction Element: initiate action to change the variable to be controlled
Process: the system of which a variable is being controlled
input
process
output
Correction Element
Control
Element
EE3511_L1
Salman Bin Abdulaziz University

28. Closed Loop Control Systems
A closed loop control system consists of five basic components:
Comparison Element: Compares required value and actual value
Control Element: Determines the action needed based on the value of the error
Correction Element: produce the change in the process to reduce the error
Process: the system of which a variable is being controlled
Measurement Element: Produces a signal that represent the value of controlled variable
EE3511_L1
Salman Bin Abdulaziz University

29. Closed Loop Control Systems
input
process
output
Correction
Element
Control
Measurement _
EE3511_L1
Salman Bin Abdulaziz University

30. Closed Loop Control Systems
The variables associated with closed loop control systems are defined as
Controlled Variable: The variable that is measured and being maintained at a desired value (OUTPUT).
Manipulated Variable: the variable that is varied by the controller.
Feedback signal: The output of the measurement device
Set point: the input value applied to the loop. It is the desired condition to the controlled variable (INPUT).
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31. Salman Bin Abdulaziz University
Example
Back to the car example. You could think of yourself as the controller. You alter the manipulated variables signals (the positions of the steering wheel, pedals, etc) so that the car follows a desired trajectory (controlled variable).
EE3511_L1
Salman Bin Abdulaziz University

32. Salman Bin Abdulaziz University
EE3511_L1
Salman Bin Abdulaziz University

33. Feedback Control System
In general
Main Components:
Plant: Process + Actuator
Controller
Sensor
Disturbance
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Salman Bin Abdulaziz University

34. Control Systems in Nature
Pancreas:
regulate blood sugar.
Adrenalin
automatically generated to increase heart rate and oxygen intake in times of flight.
Eyes
able to follow a moving object.
Hand:
able to pick up an object and place it at a predetermined location
EE3511_L1
Salman Bin Abdulaziz University

35. 3. Control Engineering Design and Examples of Modern Control Systems
EE3511: Automatic Control Systems
3. Control Engineering Design and Examples of Modern Control Systems
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Salman Bin Abdulaziz University

36. Salman Bin Abdulaziz University
Fly Ball Governor
Invented by James Watt in 1769
Steam
Turbine
Close valve
Open valve
Steam
Steam
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37. Salman Bin Abdulaziz University
Fly Ball Governor
Example of early control systems
With fly ball governor Watt’s steam engine become safer and more practical
As speed increases  the balls move away from the center  the lever moves up  the valve is closed  less steam goes to the turbine  speed decreases  the balls move to the center  the lever moves down  the valve is open  speed increases
EE3511_L1
Salman Bin Abdulaziz University

38. Water Level Float Regulator
Invented by Polzunon in 1765
Steam
Float
valve
Water Feed
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39. Salman Bin Abdulaziz University
Role
Automation/Control systems engineers are concerned with understanding and controlling segments of their environment (Systems) to provide useful economic products for society
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40. Salman Bin Abdulaziz University
Activities
Understanding
Modeling
Designing
Testing
Implementation
Monitoring
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41. Salman Bin Abdulaziz University
Automation impact
PRODUCTIVITY
and to obtain high-quality products
Material handling
Safety and Security
Etc…
EE3511_L1
Salman Bin Abdulaziz University

42. Foundation/knowledge
Feedback theory
Linear system analysis
Knowledge
Network theory
Communication theory
Reliability and maintenance theory
Safety theory
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Salman Bin Abdulaziz University

43. Salman Bin Abdulaziz University
Definition
A control system is an interconnection of components forming a system configuration that will provide a desired system response.
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44. Open-Close-Multivariable
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45. Salman Bin Abdulaziz University
Usual Representation
Every component (or process) can be represented by a block
SISO: Single input Single output
Process
Input
Output
Cause
Effect
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46. Salman Bin Abdulaziz University
Usual Representation
Actuator
Process
Desired
Output response
Output
SIMO: Single input multi-output
MISO:
MIMO:
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Salman Bin Abdulaziz University

47. Open-Loop Control System
An open-loop control system utilizes an actuating device to control the process directly without using feedback.
Actuator
Process
Desired
Output response
Output
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48. Salman Bin Abdulaziz University
Open loop system
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49. Close-Loop Feedback Control
A close-loop system uses a measurement of the output and feedback of this signal to compare it with the desired output (reference or command)
Comparison
Actuator
Process
Measurement
Desired
Output
contoroller
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50. Salman Bin Abdulaziz University
EE3511_L1
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51. Salman Bin Abdulaziz University
The design process
Definition
Design is the process of inventing the forms, parts, and details of a system to achieve a specific goal
Terminology
Specifications
alternatives
Trade-off
Synthesis
optimization
EE3511_L1
Salman Bin Abdulaziz University

52. Design of Control Systems
Establish Control Goals
Identify variables to control
Write the specifications
Establish the system configuration and identify the actuator
Obtain the models of (process, actuators, sensors)
Describe the controller, select the parameters to be adjusted
Select the values of the parameters
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53. Salman Bin Abdulaziz University
A design example
Control Goal: Design a system for rotating disk speed control that will ensure that the actual speed of rotation is within a specified percentage of the desired speed.
Variables to be controlled: Disk rotation speed
Establish the system configuration and identify the actuator:
EE3511_L1
Salman Bin Abdulaziz University

54. A design example Open loop
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55. A design example Closed-loop
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