Nguyễn Công Phương

CONTROL SYSTEM DESIGN

The Performance of Feedback Control Systems

Contents

Introduction

I. II. Mathematical Models of Systems III. State Variable Models IV. Feedback Control System Characteristics V. The Performance of Feedback Control Systems VI. The Stability of Linear Feedback Systems VII. The Root Locus Method VIII.Frequency Response Methods IX. Stability in the Frequency Domain X. The Design of Feedback Control Systems XI. The Design of State Variable Feedback Systems XII. Robust Control Systems XIII.Digital Control Systems

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2

The Performance of Feedback Control Systems

1. Introduction 2. Test Input Signals 3. Performance of Second – Order Systems 4. Effects of a Third Pole & a Zero on the Second –

Order System Response

5. The s – Plane Root Location & the Transient

Response

6. The Steady – State Error of Feedback Control Systems 7. Performance Indices 8. The Simplification of Linear Systems 9. System Performance Using Control Design Software

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3

Introduction

Performance measure, M1

Performance measure, M2

pmin

Parameter, p

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4

The Performance of Feedback Control Systems

Introduction

1. 2. Test Input Signals 3. Performance of Second – Order Systems 4. Effects of a Third Pole & a Zero on the Second –

Order System Response

5. The s – Plane Root Location & the Transient

Response

6. The Steady – State Error of Feedback Control Systems 7. Performance Indices 8. The Simplification of Linear Systems 9. System Performance Using Control Design Software

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5

Test Input Signals (1)

• If the system is stable, the response to a specific input

signal will provide several measures of the performance. • But because the actual input signal of a system is usually unknown, a standard test input signal is normally chosen.

• Using a standard input allows the designer to compare

several competing designs.

• Many control systems experience input signals that are

very similar to the standard test signals.

• 4 types:

– Unit impulse, – Step, – Ramp, – Parabolic.

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6

Test Input Signals (2)

( )r t

( )r t

A

 2

 2

t

t

0

0

,

t

,

0

  

A t ,

0

r t ( )

;

R s

( ) 1 

 2

r t ( )

;

R s ( )

0,

t

0

A s

  

1  0,

 2 otherwise

   

Unit impulse

Step

Ramp

Parabolic

( )r t

( )r t

A

t

t

0

0

2

At

,

t

0

At

,

t

0

r t ( )

;

R s ( )

r t ( )

;

R s ( )

A 3

0,

t

0

2 s

A 2 s

0,

t

0

  

   

7

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The Performance of Feedback Control Systems

1. Introduction 2. Test Input Signals 3. Performance of Second – Order Systems 4. Effects of a Third Pole & a Zero on the Second –

Order System Response

5. The s – Plane Root Location & the Transient

Response

6. The Steady – State Error of Feedback Control Systems 7. Performance Indices 8. The Simplification of Linear Systems 9. System Performance Using Control Design Software

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8

Performance of Second – Order Systems (1) ( )R s

( )Y s

G s ( )

)

s s (

2  n 2   n

( )

Y s ( )

R s ( )

1

G s ( ) G s ( ) 

R s ( )

2

s

s

2  n 2  n

2  n

R s ( )

Y s ( )

2

1   s

s s (

s

)

2  n 2  n

2  n

1

t

2

1 

 n

y t ( ) 1

e

sin(

1

t

cos

)

 

 n

2

1

t

 n

e

sin(

t

)

1  

  n

1 

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9

Performance of Second – Order Systems (2) ( )R s

( )Y s

G s ( )

)

s s (

2  n 2   n

( )

1

t

t

2

1 

 n

 n

r t ( ) 1

y t ( ) 1

e

sin(

1

t

cos

) 1

e

sin(

t

)

 

 

 

 n

  n

2

1 

1

1.8

( )y t

1.6

1.4

 = 0.1  = 0.2  = 0.4  = 0.7  = 1.1  = 2.0

1.2

1

0.8

0.6

0.4

0.2

t

0

0

3

0.5

1

1.5

2

2.5

10

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Performance of Second – Order Systems (3) ( )R s

( )Y s

G s ( )

)

s s (

2  n 2   n

( )

Y s ( )

R s ( )

1

G s ( ) G s ( ) 

R s ( )

2

s

s

2  n 2  n

2  n

R s

( ) 1

Y s ( )

 

2

s

s

2  n 2  n

2  n

t

2

 n

y t ( )

e

sin(

1

t

)

 n

2

1

 n  

t

 n

e

sin(

t

)

1  

  n

1 

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11

Performance of Second – Order Systems (4) ( )R s

( )Y s

G s ( )

)

s s (

2  n 2   n

( )

t

t

2

 n

 n

r t ( )

t ( )

y t ( )

e

sin(

1

t

) 1

e

sin(

t

)

 

 n

  n

2

1 

1

 n  

4

( )y t

3

 = 0.10  = 0.25  = 0.50  = 1.1

2

1

0

-1

-2

t

-3

0

3

0.5

1

1.5

2

2.5

12

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Performance of Second – Order Systems (5)

1

t

t

2

1 

 n

 n

r t ( ) 1

y t ( ) 1

e

sin(

1

t

cos

) 1

e

sin(

t

)

 

 

 

 n

  n

( )y t

2

1 

1

1.6

ptM

final value

ptM

Percent overshoot

100%

1.4

final value

Overshoot

2

/ 1

 

100

 e 

1.2

1.0 

1

0.9

1.0 

0.8

0.6

Peak time pT

2

0.4

1n

Settling time sT

4 n

0.2

Rise time rT 1rT

0.1

t

0

0

0.5

1

1.5

2.5

2

3.5

4

4.5

5

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13

Performance of Second – Order Systems (5)

120

Percent overshoot Peak time

100

80

60

40

20

0

0.1

0.2

0.3

0.6

0.7

0.8

0.9

1

0.4

0

0.5 Damping ratio,  sites.google.com/site/ncpdhbkhn

14

Performance of Second – Order Systems (6)

1.6

1.4

 = 10rad/s n  = 1rad/s n

1.2

1

e d u t i l

0.8

p m A

0.6

0.4

0.2

0

1

2

3

4

6

7

8

9

10

0

5 Time (s)

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15

Performance of Second – Order Systems (7)

( )R s

( )Y s

)

s s (

K p

( )

s s (

)

T s ( )

2

2

1

G s ( ) G s ( ) 

K ps K s

s

s

2  n 2  n

2  n

1

s s (

p

)

Ex. Find K & p so that the transient response to a step should be as fast as attainable while retaining an overshoot of less than 5%, and the settling time should be less than 4 seconds. K p  K 

2

/ 1

 

2

Percent overshoot

100

1

 

s 1,2

 n

j  n

2

(1/ 2 )

/ 1 (1/ 2 )

 e  

100e

4

T s

1n 

4.32%

4  n

1

j 1

1   

s 1,2

2

1

1

  n     n

2(1/ 2) 2

2

2  n

1/ 2

2

K

( 2)

2

2  n

  p   

2

        n

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16

Performance of Second – Order Systems (8)

( )R s

( )Y s

)

s s (

K p

Ex. Find K & p so that the transient response to a step should be as fast as attainable while retaining an overshoot of less than 5%, and the settling time should be less than 4 seconds.

( )

K

2;

p

2

1.4

1.2

1

) t ( y

0.8

0.6

0.4

0.2

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17

0 0 1 2 3 4 6 7 8 9 10 5 Time (s)

The Performance of Feedback Control Systems

1. Introduction 2. Test Input Signals 3. Performance of Second – Order Systems 4. Effects of a Third Pole & a Zero on the Second –

Order System Response

5. The s – Plane Root Location & the Transient

Response

6. The Steady – State Error of Feedback Control Systems 7. Performance Indices 8. The Simplification of Linear Systems 9. System Performance Using Control Design Software

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18

Effects of a Third Pole & a Zero on the Second – Order System Response (1)

T s ( )

2

(

s

s

s

1)

2 

1)( 

1 

1.4

1.2

1

) t ( y

0.8

0.6

0.4

0.2

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 = 2.25  = 1.5  = 0.9  = 0.4  = 0.05  = 0.001 0 2 4 6 8 10 12 14 0 Time (s)

Effects of a Third Pole & a Zero on the Second – Order System Response (2)

T s ( )

2

(

s

s

s

1)

2 

1)( 

1 

1 

Percent overshoot

Settling time

0.444

2.25

0

9.63

0.666

1.50

3.9

6.30

1.111

0.90

12.3

8.81

2.50

0.40

18.6

8.67

20.0

0.05

20.5

8.37

0.45

 

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T s ( )

2 (  n 2 s 

 

Effects of a Third Pole & a Zero on the Second – Order System Response (3) a s a )( / ) 2 2 s   n n

3.5 a/

a/ 3 a/

a/ = 5 n = 2 n = 1 n = 0.5 n

2.5

) t ( y

2

1.5

1

0.5

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21

0 1 2 3 4 6 7 8 9 10 0 5 Time (s)

Effects of a Third Pole & a Zero on the Second – Order System Response (4)

T s ( )

2 (  n 2 s 

 

) / a s a )( 2 s 2   n n

Percent overshoot

Settling time

Peak time

a  / n

23.1

8.0

3.0

5

39.7

7.6

2.2

2

89.9

10.1

1.8

1

210.0

10.3

1.5

0.5

0.45

 

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22

Ex.

4

3

;

T s ( ) 2

T s ( ) 1

2

s  25)(

6.25)

(

s

Effects of a Third Pole & a Zero on the Second – Order System Response (5) s 10( 62.5(  2 6 s s s 6  

2.5) 25 

2.5) s 

2

1

2

0

i

t r a P y r a n g a m

-1

I

-2

-3

-4

1

-8

-6

0

2

-4

1.6 T

2

-2 Real Part

1.4 T

1.2

1

) t ( y

0.8

0.6

0.4

0.2

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23

0 0 0.5 1 2 2.5 3 1.5 Time (s)

The Performance of Feedback Control Systems

1. Introduction 2. Test Input Signals 3. Performance of Second – Order Systems 4. Effects of a Third Pole & a Zero on the Second –

Order System Response

5. The s – Plane Root Location & the Transient

Response

6. The Steady – State Error of Feedback Control Systems 7. Performance Indices 8. The Simplification of Linear Systems 9. System Performance Using Control Design Software

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24

M

N

N

M

t

t

i

k

y t ( ) 1

Y s ( )

sin(

t

)

 

A e i

D e k

 k

k

2

The s – Plane Root Location & the Transient Response 

1   s

s

A i  

k s

)

s

i

B s C  k 2 ( 2    k

k

2  k

k

k

i

i

1 

1 

1 

1 

j

1

1

10

1

0

0

0

0

-1

-1

-1

-10

5

10

5

10

5

10

5

10

0

0

0

0

1

1

10

1

0

0

0

0

-1

-1

-1

-10

0

0

0

5

10

5

10

5

10

5

10

0

1

1

2

10

0.5

0.5

1

5

0

0

0

0

0

0

0

5

10

5

10

5

10

0

5

10

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25

The Performance of Feedback Control Systems

Introduction 1. 2. Test Input Signals 3. Performance of Second – Order Systems 4. Effects of a Third Pole & a Zero on the Second –

Order System Response

5. The s – Plane Root Location & the Transient

Response

6. The Steady – State Error of Feedback Control

Systems

7. Performance Indices 8. The Simplification of Linear Systems 9. System Performance Using Control Design Software

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26

The Steady – State Error of Feedback Control Systems (1)

( )R s

( )Y s

E s ( )

R s ( )

( )G s Process

( )

cG s ( ) Controller

1 G s G s ( ) ( )

1

c

s

R s ( )

e steady state

e t lim ( ) t 

lim s 0 

1

1 G s G s ( ) ( )

c

r t ( )

R s ( )

A  

A s

A

s

e   ss

lim s 0 

1

A G s G s s

1 ( )

( )

G s G s ( )

c

c

1 lim ( ) 0

s

K

G s G s ( )

p

0

lim ( ) c s 

e   ss

A K

1

p

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27

The Steady – State Error of Feedback Control Systems (2)

( )R s

( )Y s

E s ( )

R s ( )

( )G s Process

( )

cG s ( ) Controller

1 G s G s ( ) ( )

1

c

s

R s ( )

e steady state

e t lim ( ) t 

lim s 0 

1

1 G s G s ( ) ( )

c

r t ( )

R s ( )

At  

A 2 s

s

e   ss

lim s 0 

lim s 0 

1

1 G s G s ( ) ( )

A sG s G s ( ) ( )

A 2 s

c

c

K

sG s G s ( ) ( )

v

c

lim s 0 

e   ss

A K

v

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28

The Steady – State Error of Feedback Control Systems (3)

( )R s

( )Y s

E s ( )

R s ( )

( )G s Process

( )

cG s ( ) Controller

1 G s G s ( ) ( )

1

c

s

R s ( )

e steady state

e t lim ( ) t 

lim s 0 

1

1 G s G s ( ) ( )

c

2

r t ( )

R s ( )

At 2

A 3 s

s

e   ss

lim s 0 

lim s 0 

1

1 ( )

( )

A 3 G s G s s

A 2 s G s G s ( ) ( )

c

c

K

2 s G s G s ( ) ( )

a

c

lim s 0 

e   ss

A K

a

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29

The Steady – State Error of Feedback Control Systems (4)

( )R s

( )Y s

E s ( )

R s ( )

( )G s Process

( )

cG s ( ) Controller

1 G s G s ( ) ( )

1

c

K

G s G s K

( );

sG s G s K

( );

( )

2 s G s G s ( ) ( )

p

v

c

a

c

0

lim ( ) c s 

lim s 0 

lim s 0 

Input

Step, r(t) = A

Ramp

Parabola

2

2

3

R s ( )

A s /

At A s

/

,

At

/ 2,

A s /

Number of Integrations in Gc(s)G(s), Type Number

e ss

0

Infinite

Infinite

A K

1

p

0

1

Infinite

sse 

A K

v

0

0

2

sse 

A K

a

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30

The Steady – State Error of Feedback Control Systems (5)

Ex. 1

( )R s

( )Y s

G s ( )

G s ( ) c

K 1

K 2 s

1

K 

s

( )

R s ( )

A

  

e ss

A K

1

p

 

K

G s G s ( )

p

K 1

0

lim ( ) c s 

lim s 0 

K 2 s

1

K 

s

  

     

  

0

sse 

R s ( )

At

  

e ss

A K

v

K

sG s G s ( ) ( )

p

c

2K K

lim s 0 

lim s 0 

K 2 s

1

K 

s

 s K  1 

     

  

e   ss

A K K 2

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31

The Steady – State Error of Feedback Control Systems (6)

Ex. 1

( )R s

( )Y s

G s ( )

R s ( )

A

0

  

G s ( ) c

K 1

e ss

K 2 s

1

K 

s

( )

R s ( )

At

  

e ss

A K K 2

1

0.8

0.6

0.4 Step input Output Error

0.2

0

0 1 2 3 4 5 6 7 8

1

0.5 Ramp input Output Error

0

-0.5

32

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The Steady – State Error of Feedback Control Systems (7)

Ex. 1

( )R s

( )Y s

G s ( )

R s ( )

A

0

  

G s ( ) c

K 1

e ss

K 2 s

1

K 

s

( )

R s ( )

At

  

e ss

A K K 2

1 K

K 0.5

p e t S

f o r o r r

E

K 0 K = 0.2 2 = 2 2 = 10 2 = 20 2

-0.5

-1 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5

0.4 K 0.3 K

p m a R

f

o

K 0.2

r o r r

E

K = 0.2 2 = 2 2 = 10 2 = 20 2 0.1

0

33

-0.1 0 0.5 1 1.5 2.5 3 3.5 4 4.5 5 2 sites.google.com/site/ncpdhbkhn

( )R s

( )Y s

1K

( )G s Process

( )

The Steady – State Error of Feedback Control Systems (8) cG s ( ) Controller

( )H s Sensor

H s ( )

1

K 1 s 

1

E s ( )

R s ( )

K G s G s ( )] ( ) c K G s G s ( ) ( )

[1 1 s    s 1   

1

c

e   ss

0

lim ( ) sE s s 

1

K 1

0

1 lim ( ) G s G s ( ) c s 

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34

The Steady – State Error of Feedback Control Systems (9)

Ex. 2

( )R s

( )Y s

1K

( )

40 Controller

1 5s  Process

3

2 Step input Output Error

2 1s  0.1 Sensor

1

e ss

0

1

K 1

0

1 G s G s ( ) lim ( ) c s 

-1

1

-2 1 2 3 4 5 6 7 8 0

1.5

0

1 2 lim 40 s 

5

1

1 s  5.9%

0.059

Ramp input Output Error 0.5

0

-0.5

-1

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-1.5 0 1 2 3 4 5 6 7 8

The Steady – State Error of Feedback Control Systems (10)

( )R s

( )Y s

K Controller

Ex. 3 Find K so that the steady – state error to a step input is minimize?

( )

1 5s  Process

T s ( )

G s G s ( ) ( ) c G s G s H s ( ) ( ) ( )

1

K s ( s 2)(

K

(

s

 

4) 4) 2 

c

2 4s  Sensor

E s ( )

R s ( )

Y s ( )

R s ( )

T s R s ( ) ( )

1.2

  ( )] ( ) T s R s

[1  

1

0.8

R s ( )

  

e ss

0

lim ( ) sE s s 

1 s

0.6

T s

( )]

1 s

Step input Output Error 0.4

(0)

lim [1 s 0 s  1 T  

0.2

T

(0)

K

1

4

0  

  

0

e ss

K

4 K 8 2 

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36

-0.2 0 0.5 1 1.5 2 2.5 3

The Performance of Feedback Control Systems

1. Introduction 2. Test Input Signals 3. Performance of Second – Order Systems 4. Effects of a Third Pole & a Zero on the Second –

Order System Response

5. The s – Plane Root Location & the Transient

Response

6. The Steady – State Error of Feedback Control Systems 7. Performance Indices 8. The Simplification of Linear Systems 9. System Performance Using Control Design Software

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37

Performance Indices (1)

• A performance index is a quantitative measure of the performance of a system and is chosen so that emphasis is given to the important system specifications.

• A system is considered an optimum control system when the system parameters are adjusted so that the index reaches an extremum, commonly a minimum value.

• A performance index must be a number that is

always positive or zero.

• Then the best system is defined as the system that

minimizes this index.

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38

Performance Indices (2)

1 e(t)=r(t)-y(t) 0.5

0

-0.5

The Integral of the Square of the Error

T

-1 0 5 10 15 20

ISE

2 e t dt ( )

1

 

0

e2(t) 0.8

0.6

0.4

0.2

0 0 5 10 15 20

100 2

80 1.5 Input r(t) Output y(t)

60 1 40

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39

0.5 20 ISE 0 0 0 0 5 10 15 20 5 10 15 20

T

e t dt ( )

IAE

Integral of Absolute magnitude of Error, IAE 200

Performance Indices (3)  

0

T

150

ITAE

t e t dt ( )

 

0

100

T

50

2

ITSE

te t dt ( )

 

0

0 5 10 15 20 0

Integral of Time multiplied by Absolute Error, ITAE 3000 1 e(t)=r(t)-y(t) 0.5 2000

0

1000 -0.5

0 -1 5 10 15 20 5 10 15 20 0 0

Integral of Time multiplied by Squared Error, ITSE 250 100

200 80

150 60

100 40

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50 20 ISE 0 0 5 10 15 20 5 10 15 0 0 20 40

Performance Indices (4)

Ex. 1

( )R s

( )Y s

T s ( )

2

2

1 2s 

1 s

( )

1

s

1 s 2

s

1 s 2 0.75

1

 

8

7 ISE ITAE ITSE

6

i

5

s e c d n I

4

3

2

1

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41

0 0 0.2 0.4 0.6 0.8 1.2 1.4 1.6 1.8 2 1 

dT s ( )

( )R s

( )Y s

( )X s

Performance Indices (5) 1K s

2K s

Ex. 2 Find K3 to minimize the effect of the disturbance?

( )

( )

P k

k

3K

k 

Y s ( ) T s ( ) d

pK

N

...

1   

L n

L L n m

L L L n m p

n

,

1 

n m , nontouching

n m p , nontouching

= 1 – (sum of all different loop gains)

+ (sum of the gain products of all combinations of two nontouching loops) – (sum of the gain products of all combinations of three nontouching loops) + ...

K

K

1  

3

p

K 1 s

K K 1 2 s s

  

  

    

  

  

  

1 

2 

K

K

1  

1  

3

p

K K s 1 3

K K K s 2 p

1

K 1 s

K K 1 2 s s

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42

dT s ( )

( )R s

( )Y s

( )X s

Performance Indices (6) 1K s

2K s

Ex. 2 Find K3 to minimize the effect of the disturbance?

( )

( )

P k

k

3K

k 

Y s ( ) T s ( ) d

pK

1 

2 

1   

K K s 1 3

K K K s 2 p

1

Pk: gain of kth path from input to output Δk (cofactor): the determinant Δ with the loop(s) touching the kth path removed.

1 1P 

1 

2 

  

1  

1

K K s 1 3

Loop of

removed

K K K s p

1 2

1 

)

3

2

2 

1

s

s s K K (  1 K K s K K K 

Y s ( ) T s ( ) d

1(1 ) K K s  3 1 1  K K s K K K s  1 3 2 p

1

1

3

2

1

p

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43

dT s ( )

( )R s

( )Y s

( )X s

Performance Indices (7) 1K s

2K s

( )

( )

Ex. 2 Find K3 to minimize the effect of the disturbance? )

3

2

3K

s

s s K K (  1 K K s K K K 

Y s ( ) T s ( ) d

1

3

2

1

p

pK

0.5;

2.5

K 1

K K K 2

1

p

s

( ) 1/ 

dT s

Y s ( )

.

2

1 s

 0.5

) 2.5

s

( s s 

K 0.5 3 K s  3

0.25

2

K t 3

y t ( )

sin

t

K

/ 2)

,

10 ( 

3

 2

10 

  

  

 e  

  

0.5

2

2

K t 3

I

y t dt ( )

e

sin

t

dt

0.1K

3

0

0

 2

1 K

10 2 

  

  

3

10

3.2

K 

K

 

0.1 0 

3

2  3

dI dK

3

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44

dT s ( )

( )R s

( )Y s

( )X s

Performance Indices (8) 1K s

2K s

Ex. 2 Find K3 to minimize the effect of the disturbance?

( )

( )

3K

2

 1.6

2.5

s

s s ( 

1.6) s 

Y s ( ) T s ( ) d

pK

1.2

1

0.8

0.6

(t) t d y(t) 0.4

0.2

0

-0.2 0 1 2 3 5 7 6 8 9 10

45

4 sites.google.com/site/ncpdhbkhn

The Performance of Feedback Control Systems

1. Introduction 2. Test Input Signals 3. Performance of Second – Order Systems 4. Effects of a Third Pole & a Zero on the Second –

Order System Response

5. The s – Plane Root Location & the Transient

Response

6. The Steady – State Error of Feedback Control Systems 7. Performance Indices 8. The Simplification of Linear Systems 9. System Performance Using Control Design Software

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46

Ex. 1

,

T s ( ) 2

T s ( ) 1

K s s (

K 2)(

s s (

s

10)

The Simplification of Linear Systems (1) /10 2) 

1

0.8

1

0.6 T

0.4

0.2

0 0 1 2 3 4 5 6

1

0.8

2

0.6 T

0.4

0.2

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47

0 0 1 2 3 4 5 6

p

m

m

1 

1

...  

K

K

,

p

n

g  

G s ( ) L

G s ( ) H

g

n

1 

1

...   ...  

 

...  

a s m b s n

c s 1 d s 1

The Simplification of Linear Systems (2) c s s 1 a a s  p m 1 1   n 1 b s d s b s  g n 1 1 

G s M s ( ) ( ) H  s G s ( ) ( ) L

k

k ( ) M s ( )

M s ( )

k

k ( )

s ( )

s ( )

k

d ds k d ds

2

q

k ( )

(2

)

k q 

q k 

(0)

( 1) 

M

,

q

0,1, 2,...

2

q

M k

!(2

M (0) q k )! 

k

0

2

q

(2

)

k ( )

k q 

q k 

(0)

( 1) 

,

q

0,1, 2,...

  2 q

 !(2 k

)!

(0)  q k 

k

0

M

q

1, 2,...)

c d ,

 

2

q

2 ( q

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48

The Simplification of Linear Systems (3)

Ex. 1

G s ( ) H

G s ( ) L

3

2

s

10

s

16

s

10

1

10 2 

1 d s  1

d s 2

HG s ( )

3

s 0.1

s

1.6

s

1

1 2 

2

M s ( ) s ( ) 

 2 s

1 s

1

d s 2 3 s 0.1 

d s  1 1.6 

G s ( ) H G s ( ) L

2

(0)

(0)

3

2

(0)

(0) M s ( )

M

s

1.6

s

1

1  

(0) 1 

( ) 0.1 s s 

  

(0) 1 

d s 2

d s 1

(1)

(1)

(1)

2

(1) M s

M

(0)

2

s

1.6

( ) 2 

( ) 0.3 s s 

  

(0) 1.6 

d s d   1

2

d 1

(2)

(2)

(2)

s

2

(2) M s

( ) 2

M

d

( ) 0.6 s 

  

(0) 2 

(0) 2 

d   2

2

(3)

(3)

(3)

(3) M s

( ) 0

M

s ( ) 0.6

 

(0) 0 

  

(0) 0.6 

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49

The Simplification of Linear Systems (4)

Ex. 1

G s ( ) H

G s ( ) L

3

2

s

10

s

16

s

10

1

10 2 

1 d s  1

d s 2

(0)

(1)

(2)

(3)

M

M

(0)

(0) 1, 

(0) 0 

d M , 1

(0) 2 , d M  2

(0)

(1)

(2)

(3)

(0) 1,

 

(0) 1.6, 

(0) 2, 

(0) 0.6 

2

q

k ( )

(2

)

k q 

q k 

(0)

( 1) 

M

2

q

M k

!(2

(0) M q k )! 

k

0

(1)

(0)

(2 0) 

1 1 

(2 1) 

0 1 

(0)

(0)

( 1) 

( 1) 

q

M

1

  

2

M M (0) 1!(2 1)! 

M M (0) 0!(2 0)!  (2) 2 1 

(2 2) 

(0)

( 1) 

M M (0) 2!(2 2)! 

(0)

(2)

(1)

(1)

(2)

(0)

M

M

(0)

M

(0)

M

M

(0)

( 1) 

( 1) 

M (0) 1

(0) 2

(0) 2

d

2

1

2

2

d

 

2 d 1

2

d 2 2

1 2   2

d d 1 1 1

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50

The Simplification of Linear Systems (5)

Ex. 1

G s ( ) H

G s ( ) L

3

2

s

10

s

16

s

10

1

10 2 

1 d s  1

d s 2

(0)

(1)

(2)

(3)

M

M

(0)

M

d

(0) 1, 

(0) 0, 

2  

d M , 1

(0) 2 , d M  2

2

2 d 1

2

(0)

(1)

(2)

(3)

(0) 1,

 

(0) 1.6, 

(0) 2, 

(0) 0.6 

2

q

(2

)

k ( )

k q 

q k 

(0)

( 1) 

  q 2

 !(2 k

)!

(0)  q k 

k

0

(1)

(0)

(2 0) 

1 1 

(2 1) 

0 1 

(0)

(0)

( 1) 

( 1) 

q

1

   

2

(0)   1!(2 1)! 

(0)   0!(2 0)!  (2) 2 1 

(2 2) 

(0)

( 1) 

(0)   2!(2 2)! 

(1)

(1)

(2)

(0)

(0)

(2)

(0)

(0)

(0)

( 1)  

( 1)  

(0)  1

(0) 2

0.56

(0) 2 1 2 1.6 1.6   2

 1

2 1   2

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51

The Simplification of Linear Systems (6)

Ex. 1

G s ( ) H

G s ( ) L

3

2

s

10

s

16

s

10

1

10 2 

1 d s  1

d s 2

(0)

(1)

(2)

(3)

M

M

(0)

M

d

(0) 1, 

(0) 0, 

2  

d M , 1

(0) 2 , d M  2

2

2 d 1

2

(0)

(1)

(2)

(3)

(0) 1,

0.56

 

(0) 1.6, 

(0) 2, 

(0) 0.6, 

  2

M

2

d

0.56

d 

2

    2

2

2 d 1

(2)

(2)

(0)

(4)

1 1.4864 (1) (3)

M

(0)

(0)

M

(0)

M

q

M

2

  

4

M (0) 2!2!

(4)

(3)

(0)

M

(0)

M

2 2d

M (0) 0!4! (1) M (0) 3!1! (1)

(3)

M (0) 1!3! (0) M (0) 4!0! (2)

(2)

(0)

(4)

(0)

(0)

(0)

  4

(0)  2!2!

(4)

(0)

(1)

(3)

(0)

(0)

0.68

(0)  1!3! (0)  4!0!

0.8246

d 

d

M

0.68

   

(0)  0!4! (0)  3!1! 2 2

4

4

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52

The Simplification of Linear Systems (7)

Ex. 1

G s ( ) H

G s ( ) L

3

2

2

s

10

s

16

s

10

1

10 2 

0.8246

s

s

1

1 1.4864 

1 d s  1

d s 2

1

0.8

H

0.6 G

0.4

0.2

0 1 2 3 4 5 6 7 8 9 10 0

1

0.8

0.6 G L

0.4

0.2

53

0 1 2 3 4 5 7 8 9 10 0 6 sites.google.com/site/ncpdhbkhn

The Simplification of Linear Systems (8)

Ex. 1

G s ( ) H

G s ( ) L

3

2

2

s

10

s

16

s

10

1

10 2 

0.8246

s

s

1

1 1.4864 

1 d s  1

d s 2

G

H

G L

1

3

0.8

0.6

2

0.4

1

0.2

3

2

0

0

i

i

-0.2

t r a P y r a n g a m

t r a P y r a n g a m

I

I

-1

-0.4

-2

-0.6

-0.8

-3

-1

-8

-7

-6

-5

-2

-1

0

1

-1

-0.5

0.5

1

-4 -3 Real Part

0 Real Part

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54

The Performance of Feedback Control Systems

Introduction 1. 2. Test Input Signals 3. Performance of Second – Order Systems 4. Effects of a Third Pole & a Zero on the Second –

Order System Response

5. The s – Plane Root Location & the Transient

Response

6. The Steady – State Error of Feedback Control Systems 7. Performance Indices 8. The Simplification of Linear Systems 9. System Performance Using Control Design

Software

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55

System Performance Using Control Design Software

Ex.

( )R s

( )Y s

s

2

G s ( )

G s ( ) c

 s

1 s 0.1

1

( )

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56