Control Systems by Jagan, N. C

hi_china59

Control Systems
Author(s):  Jagan, N. C  
Publisher:  Hyderabad BS Publications  
Date:  2008  
ISBN10:  8178001772   
Pages:  485


Contents
1 Introduction 1
1. 1 Why Automatic Control ? .................................................................... 1
1.2 Open Loop and Closed Loop Control Systems ................................ 2
1 .3 Open Loop Vs Closed Loop Control Systems ................................... 3
1.4 Feedback Control Systems ................................................................ 4
1.5 Classification of Control Systems ...................................................... 4
1.5.1 Continuous Time Feedback Control Systems ..................... 5
1.5.2 Discrete Data Feedback Control Systems .......................... 5
1.5.3 Linear Control Systems ........................................................ 6
1.5.4 Non-Linear Control Systems ................................................ 6
2 Mathematical Modelling of Physical Systems 8
2.1 Introduction ............................................................. , ........................... 8
2.2 Mathematical Models of Physical Systems ........................................ 8
2.2.1 Electrical Systems ................................................................. 9
2.2.2 Dual Networks ..................................................................... 14
2.2.3 Mechanical Systems ........................................................... 15
2.2.4 Analogous Systems ............................................................ 18
2.2.5 Gears ................................................................................... 24
2.2.6 Thermal Systems ................................................................ 27
2.2.7 Fluid Systems ...................................................................... 29
Contents
2.3 Block Diagrams of Closed Loop Syst~ms ........................................ 34
2.3.1 Block Diagram Reduction Techniques ............................... 35
2.4 Signal Flow Graph Representation of Control Systems ................. 42
2.4.1 Construction of a Signal Flow Graph for a System ........... 43
2.4.2 Mason's Gain Formula ....................................................... 44
2.5 Effects of Feedback ......................................................................... 52
2.5.1 Effect on system dynamics ................................................. 53
2.5.2 Effect due to parameter variations .................................... 54
2.5.3 Effect on Bandwidth ............................................................ 57
2.5.4 Effect on Noise Signals ....................................................... 58
2.6 Modelling of Elements of Control Systems ...................................... 59
2.6.1 DC Servo Motor .................................................................. 59
2.6.2 AC Servo Motors ................................................................. 63
2.6.3 Synchros ............................................................................. 65
2.6.4 AC Tacho Generator ........................................................... 68
2.6.5 DC Tacho Generator .......................................................... 69
2.6.6 Potentiometers .................................................................... 69
2.6.7 Stepper Motors ................................................................... 71
Problems ........................................................................................ ~ ............ 73
3 Time Response Analysis of Control Systems 81
3.1 Introduction ....................................................................................... 81
3.2 Standard Test Signals ....................................................................... 81
3.2.1 Impulse Signal ....................................................................... 81
3.2.2 Step Signal ........................................................................... 82
3.2.3 Ramp signal .......................................................................... 82
3.2.4 Parabolic signal .................................................................... 82
3.3 Representation of Systems .............................................................. 83
3.4 First Order System ........................................................................... 85
3.4.1 Response to a Unit Step Input ............................................. 85
3.4.2 Response to a Unit Ramp Input or Unit Velocity Input ........ 86
3.4.3 Response to a Unit Parabolic or Acceleration Input ............ 87
3.5 Second Order System ...................................................................... 88
3.5.1 Response to a Unit Step Input ............................................. 88
3.5.2 Response to a Unit Ramp Input ........................................... 92
3.5.3 Time Domain Specifications of a Second Order System ..... 93
Contents
3.6 Steady State Errors .......................................................................... 99
3.6.1 Error Constants .................................................................... 99
3.6.2 Dependence of Steadystate Error on Type of the System 101
3.6.3 Generalized Error Coefficients - Error Series .................... 104
3.7 Design Specifications of a Control System .................................... 113
3.7.1 Proportional Derivative Error Control (PD control) ........... 114
3.7.2 Proportional Integral Controller (PI Control) ...................... 115
3.7.3 Proportional, Integral and Derivative Controller
(PID Control) ....................................................................... 116
3.7.4 Derivative Output Control ................................................... 116
Problems ................................................................................................... 125
4 Stability of Systems 129
4.1 Introduction ..................................................................................... 129
4.2 Stability Preliminaries ...................................................................... 130
4.3 Necessary Conditions for Stability ................................................. 133
4.4 Routh - Hurwitz Stability Criterion ................................................... 134
4.5 Special Cases ................................................................................. 137
4.6 Relative Stability ............................................................................. 147
Problems ................................................................................................... 149
5 Root Locus Analysis 151
5.1 Introduction ..................................................................................... 151
5.2 Basic Idea ....................................................................................... 151
5.3 Development of Root Locus Technique ........................................ 153
5.4 Properties of Root Locus ............................................................... 155
Problems ................................................................................................... 187
6 F,r equency Response of Control Systems 190
6.1 Introduction ..................................................................................... 190
6.2 Time Domain AnalysiS Vs Frequency Domain Analysis ................ 190
6.3 Frequency Response of a Control System ................................... 191
6.4 Correlation Between Time Response and
Frequency Response ..................................................................... 194
Contents
6.5 Graphical Representation of Transfer Functions ......................... 196
6.5.1 Bode plots .......................................................................... 196
6.5,2 Polar Plots .......................................................................... 218
6.5.3 Log Magnitude Vs Phase Plots ......................................... 222
6.6 All Pass Systems ............................................................................ 223
6.7 Minimum Phase Systems ................................................................ 224
Problems ................................................................................................... 226
7 Nyquist Stability Criterion and
Closed Loop Frequency Response
229
7.1 Introduction ..................................................................................... 229
7.2 Principle of Argument ..................................................................... 230
7.3 Development of Nyquist Criterion .................................................. 234
7.3.1 Nyquist Contour ................................................................. 234
7.3.2 Nyquist Stability Criterion ........................ " ......................... 234
7.3.3 Nyquist Contour When Open Loop Poles Occur
on jro-axis ............................................................................ 236
7.3.4 Nyquist Stability Criterion for Systems which are
Open Loop Stable .............................................................. 252
7.4 Relative Stability ............................................................................ 254
7.4.1 Measures of Relative Stability: Gain Margin .................... 256
7.4.2 Phase Margin ..................................................................... 257
7.4.3 Adjustment of Gain K for Desired Values of Gain and
Phase Margins Using Polar Plots ...................................... 260
7.4.4 Gain Margin and Phase Margin Using Bode Plot ............. 261
7.5 Closed Loop Frequency Response .............................................. 264
7.5.1 Constant M Circles ............................................................ 267
7.5.2 Constant N circles .............................................................. 269
7.5.3 Nichols Charts .................................................................... 272
Problems ................................................................................................... 277
8 Design in Frequency Domain 281
8.1 Preliminaries of Design .................................................................. 281
8.2 A Design Example ........................................................................... 282
8.3 Realisation of Compensators and their Characteristics ............... 285
Contents
8.3.1 Lead Compensator ............................................................ 286
8.3.2 Lag Compensator .................................................. ..... ...... 290
8.3.3 Lag-Lead Compensator .................. ... ........ ....................... 291
8.4 Cascade Compensation in Frequency Domain Using
Bode Plols ......... .. .. ... ....................... ......... .................................... 293
8.4.1 Design of Lead Compensatot ......... ................................. 293
8.4.2 Design of Lag Compensator ................................ ......... .. .. 304
8.4.3 Design of Lag-Lead Compensator . . ...... ............. .. 311
Problems .......•.•........•••.........••......•••••....••••••...•..•••••....•••••••......••••......•••••.•. 316
9 State Space Analysis of Control Systems 318
9.1 Introduction ...................................... .............................................. 318
9.2 State Variables .. ...... ................................... ... ....... .. ........................ 319
9.3 State Equations for Linear Systems ........... ............ ....................... 321
9.4 Canonical Forms of State Models of Linear Systems ..... ...... ..... ... 324
9.4.1 Phase Variable Form ... ......... ........... ... ........ .......... ............ 324
9.4.2 Diagonal Form . . .... ... 330
9.5 Transfer Function from State Model ... ... .. 334
9.6 Diagonalisation ................................. ............................................. 337
9.6.1 Eigenvalues and Eigenvectors .................................. ... .. .. 337
9.7 Solution of State Equation .............................. ............................... 345
9.7.1 Properties of Statp. Transition Matrix ................................. 346
9.7.2 Methods of Computing State Transition Matrix .. .. .......... ... 346
9.8 Qualitative Analysis of Control Systems ..... ... ....... ..... .... .............. 358
9.8.1 S1ale Controllability ..... ..... ..... ...... ......... ................ . 358
9.8.2 ObseNability ........... .................. . ...... ...... ..... .. 366
9.8.3 Duality Principle ................................. ... .. 372
Problems ................................................................................................... 373
Answers to Problems ............................................................................. 377
MCQ's from Competitive Examinations ............................................. 387
Answers to MCQ's .................................................................................. 481

过路心客

Thanks for sharing!

amswu

多谢！！！！！！！！！！！！！

apteye

thanks

liuzhieetop

Thanks for sharing!

lujunfeng111

可惜是扫描版的书。

adnan

good book

richyrichy

This is an old textbook (2008). However it's a good reference for beginners.

chenxiaoming

hankan

Hello404

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