EE-379
LINEAR CONTROL SYSTEMS
Lecture No 1
“CONTROL SYSTEMS ENGINEERING”
By NORMAN S. NISE, 6th Edition
Text Book: Chapter 1
Instructor: Dr. Iftikhar Ahmad
Class: BEE 5 D
Electrical Engineering Department
1
Course Information
Course Title: LINEAR CONTROL
SYSTEMS
Lab (yes)
Credit hrs: 3-3
Prerequisites For this Course: Calculus, Complex Variables and
Transforms, Machines
Instructor:
Dr. Iftikhar Ahmad
e-mail :iftikhar.rana@seecs.edu.pk
SMRIMMS, Room: C-302
Control Systems Engineering
by Norman S. Nise
6th Edition
Reference Book(s):
1. Feedback Control Systems by Phillip and Harbor 4th Edition
2. MODERN CONTROL SYSTEMS by RICHARD C DORF
Text Book:.
2
Main Topics
No.
Topics
1
Introduction
2
Modeling in the frequency domain
3
Time response of systems
4
Reduction of multiple subsystems
5
Steady state errors
OHT-1
6
Root locus
7
Design via root locus
8
Frequency response techniques
OHT-2
9
Design via frequency response
10
Modeling in time domain – State Space
11
Design via State Space
End Semester Exam
3
Assignments & Lab Reports:
• The assignments will be submitted as desired by the instructor.
• The labs will be conducted every week.
Grading Policy:
Quizzes
Assignments
OHT 1
OHT 2
End Semester Test
:
:
:
:
:
10 %
5%
12.5 %
12.5%
35%
Labs
:
25 %
10% Lab report
5% Viva
10% Lab Exam
4
5
The point is learning,
Learning requires effort.
There are no shortcuts here!
Every time you seek to find a shortcut in learning, what you are actually
doing is cheating yourself.
Grade: F or D
Learner
Lecture, Book, etc.
Information
Source
Class
Input
6
First:
Never ever limit yourself to a single source of information
Use multiple sources
Lecture, Book, etc.
Grade: C
Information source
ask an expert
Learner
Information source
read a book
Information source
read another book
Information source
Internet search
7
Secondly: Your use of information sources must be full of life to be fully effective.
Approach each of your sources with specific questions in mind, with the goal of finding
answers to those questions:
Grade: C+ or B
Query
Information source
ask an expert
Query
Learner
Information source
read a book
Information source
read another book
Information source
Internet search
Query
Query
8
Thirdly: Apply what you collect from your sources.
Don't just let that information lie idle in your brain – put it into
immediate action.
This is where you begin to construct your own understanding:
Grade: B+
Application
Write in your own words
Application
Describe what U learn
output
Application
Teach your friend
Application
Build something
Application
9
Practice, practice, practice
Lastly: Treat the results of your application as another source of information, querying
and learning from these efforts as though they were primary sources (like experts or
books). This last step establishes a feedback loop, enabling the learner to self-correct
errors in understanding:
Grade: A
10
Attendance and Expectations
Attendance in class is Mandatory
Class Etiquette:
(1) Don’t read other inappropriate materials in the class
(2) Don’t talk to anyone other than the instructor
(3) Don’t arrive late or leave early
(4) Don’t do work unrelated to this class
(5) Don’t sleep in class
(8) Don’t use cell phones in the class
(9) Don’t violate NUST Code of Student Conduct
11
Synchronous Machine Main Field
Slip
rings
Pole
Fan
DC excitation
winding
ROTOR
STATOR
Main Armature
Red
Yellow
Three-Phase output
Blue
18
E A  K
13
Control Systems (Definition)
Comprises subsystems and processes (or plants) assembled for
the purpose of obtaining a desired output with desired
performance, given a specified input.
Signals flow from the input, through the system and
produce an output
14
Control Systems (Example)
Consider an elevator. When the fourth-floor button is pressed,
the elevator rises to the fourth floor with a speed and floorleveling accuracy designed for passenger comfort.
Two measures of
performance are :
(1) the transient
response
(2) the steady-state
error.
Passenger comfort and passenger patience are dependent
upon the transient response
15
Classification of Control Systems
Control Systems
Natural
Man-made
Manual
Automatic
Open-loop
Non-linear
linear
Time variant Time invariant
Closed-loop
Non-linear
linear
Time variant
Time invariant
16
System Configurations
Block diagrams of control systems:
open-loop system
closed-loop system
17
Antenna azimuth position control system:
system concept
detailed layout
18
Antenna azimuth position
control system:
Schematic diagram
functional block diagram
19
Response of a position control system showing effect of
high and low controller gain on the output response
20
The control system design process
21
One Example
Disturbance
Forces
Desired
position
R (s)
Control algorithm
(Brain)
Controller
Reference
Neural
Signal
Hand
G(s)
Muscle
Actuator
Control block
U (s)
Output
Position
Y(s)
Plant
Input
Eye
Sensor
Open loop
No Feedback
Closed loop
With Feedback
22
Another Example
Disturbances
parties, games
Desired
Performance
Teaching
activities
Actuator
Pedagogism
R (s)
Controller
Reference
performance
Students
U (s)
Control block
Y(s)
Plant
Input
Homework,
Exams, quizzes,…
Sensor
Open loop
No Feedback
Closed loop
With Feedback
Blindly teaching ?!
23
What is a Actuator?
• Actuator is a device which
produce
mechanical energy (output motion) in
response to some type of energy input.
Complex
Electrical
Mechanical
Thermal
Energy
Fluid
• Hydraulic
• Pneumatic
Actuator
Motion
Linear
ElectroMechanical
Rotary
Chemical
26
What is a sensor?
Sensors are transducers that produce (transform) electrical
energy (signals) as a result of some type of stimulation
(measurement space)
Temperature
Distance
Measurement
Sensor
Electrical
Signals
Voltage
Voltage
Current
Digital
Force
Speed
Types of Sensors
Active..
Need External Power
27
Passive.. No External Power
Use of Sensors in
Feedback Control:
In The Next 3-Slides
Air condition
Cooling System
is explained
28
Temperature
+
-
200C
220V, 50Hz
150C
mV
15
20
WAPDA Supply
Reference Error=0 volts
20mV=
200C
+
-
+-
200C
Compensator
Desired
Gain=10
20mV
Amplifier
(Op-Amp
2mV
Thermistor
Converts
Heat into
volts
29
Temperature
+
-
200C
220V, 50Hz
150C
mV
15
Reference
20mV=200C
+-
20
WAPDA Supply
Error=+5 v
150C
Compensator
Desired
Gain=10
15mV
1.5mV
30
Temperature
+
-
200C
220V, 50Hz
150C
mV
15
20
WAPDA Supply
Error= -5 v
Reference
20mV=200C
+-
250C
Compensator
Desired
Gain=10
25mV
2.5mV
31
???
32