Lecture on Modern Control Systems - an Introduction
1. Dr. Abusabah I. A. Ahmed
abusabah22@hotmail.com
Modern Control Systems
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Course Outline
❑Introduction and basic Concepts
❑State Space Design
❑Modelling and state space description of dynamic
systems
❑Realization of transfer function
❑State space analysis (State-space Solution)
❑Properties of the state space model : Stability,
Controllability, Observability and detectability.
❑State space Feedback: pole placement using state feedback
❑Observer, and observer based control design
❑Adaptive Control Systems
❑Fuzzy Logic Control Systems
❑Artificial Neural Networks
Abusabah I. A. Ahmed
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Text Books
2. P. N. Paraskevopoulos, “Modern Control
Engineering”, Marcel Dekker, Inc. , 2002.
Abusabah I. A. Ahmed
1. Katsuhiko Ogata, “Modern Control
Engineering”,4th edition, Prentice Hall,
2002.
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Course Evaluation
❑ Home works: 5%
❑ Class works : 5%
❑ Mid-term Exam: 20%
❑ Final exam: 70%
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Lecture Outline
❑ Introduction
❑ Modern Control
❑ State Space Concept
❑ State Space representation of Transfer
Function
❑ Practice Problem
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Introduction
❑ Automatic control is one of today’s most significant areas of
science and technology.
❑ This can be attributed to the fact that automation is linked to the
development of almost every form of technology.
❑ Automatic control requires both a rather strong mathematical
foundation, and implementation skills to work with controllers in
practice.
❑ It is important to mention that modern technology has, in certain
cases, succeeded in replacing body organs or mechanisms, as for
example in replacing a human hand, cut off at the wrist, with an
artificial hand that can move its fingers automatically, as if it were a
natural hand.
❑ Although the use of this artificial hand is usually limited to simple
tasks, such as opening a door, lifting an object, and eating, all these
functions are a great relief to people who were unfortunate enough
to lose a hand.
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Classical Modern
Suitable for SISO Systems Suitable for SISO and MIMO
Systems
Suitable for analysis of linear
Systems
Suitable for analysis of linear
and nonlinear systems
Suitable for analysis of time
invariant
Suitable for analysis of time
invariant and time varying
Systems
It uses frequency domain It is a time domain approach
❑Modem control has many advantages over classical control. The
following table shows a comparison between the two techniques
Modern control
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State Space Representation of TF
❑ Transfer Functions can be represented by a
variety of state space forms.
❑ Some of these are:
✓Controllable canonical form
✓Observable canonical form
✓Diagonal form
✓Jordan form
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State Space Representation of TF
Controllable Canonical Form (CCF)
❑ Consider the system described by
This equation can be written
The following State Space representation is known as
Controllable Canonical Form (CCF)
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State Space Representation of TF
Controllable Canonical Form (CCF)
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State Space Representation of TF
Controllable Canonical Form (CCF)
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State Space Representation of TF
Observable Canonical Form (OCF)
Note that the 𝑛 × 𝑛 state matrix of state equation is the
transpose of the controllable canonical form state equation
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State Space Representation of TF
Diagonal Canonical Form (DCF)
For distinct root case the transfer function can be written as
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State Space Representation of TF
Diagonal Canonical Form (DCF)
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State Space Representation of TF
Jordan Canonical Form (JCF)
❑In the case where the denominator polynomial involves repeated
roots, the diagonal form must be modified into the Jordan canonical
form.
❑Suppose ,for example, that the Pi’s are different from one another
except that the first three Pi’s are equal, or P1=P2=P3 . Then the
factored form of the TF becomes
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State Space Representation of TF
Jordan Canonical Form (JCF)
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State Space Representation of TF
Example 1-1
Obtain state representation in the Controllable Canonical Form,
Observable Canonical Form and Diagonal Canonical Form!
Solution
b0= 0
Controllable Canonical Form:
Observable Canonical Form
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State Space Representation of TF
Diagonal Canonical Form
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Practice Problem
𝑌(𝑠)
𝑈(𝑠)
=
𝑠2 + 2𝑠 + 3
𝑠3 + 5𝑠2 + 3𝑠 + 2
Obtain state representation in the Controllable
Canonical Form, Observable Canonical Form and
Diagonal Canonical Form for the following TF!