《TEXTBOOK OF SERVOMECHANISMS》求取 ⇩

1．INTRODUCTION9

1．1Servomechanisms9

1．2 Development10

2．OPEN AND CLOSED LOOP CONTROL12

2．1The Concept of Error12

2．2 R．P．C．Systems13

2．3 Further Types of Control Systems14

3．SIMPLE POSITION CONTROL15

3．1A Specific System15

3．2 The Amplifier and Motor16

3．3 Performance of the Model18

3．4 Damping21

3．5 Numerical Examples22

4．FRICTION DAMPING24

4．1Friction24

4．2 Coulomb Friction24

4．3Viscous Friction28

4．3．1 Velocity Input Test31

4．3．2 Summary of Viscous Friction Damping32

4．4 Numerical Examples32

5．OUTPUT VELOCITY FEEDBACK34

5．1Physical Implication of Damping34

5．2 Velocity Feedback in the Model34

5．3 The Response in the Phase Plane37

5．4 Numerical Examples40

6．THE SERVOMECHANISM AS A NETWORK42

6．1Four Terminal Networks42

6．2 The Transfer Function45

6．3 Single Feedback Loops49

6．4Sinple Feedback Examples51

6．4．1 The Anode Follower53

6．4．2 The Integrator54

6．4．3 The Differentiating Circuit55

6．5 Frequency Response Plotting56

7．ALTERNATIVE DAMPING METHODS62

7．1The Elimination of Velocity Lag62

7．2 Transient Velocity Feedback62

7．3 Input Derivative Feedforward—Output Derivative Feedback66

7．4 ＂Phase Advance＂or Derivative of Error Damping68

7．5 Numerical Examples73

8．STABILITY75

8．1Additional Time Constants in R．P．C．Systems75

8．1．1 Field Build-up Time75

8．1．2 Phase-advance Networks75

8．1．3 Error Smoothing76

8．1．4 Power Amplifiers76

8．2 Velocity Feedback System with Field Build-up Time76

8．3 Phase Advance Stabilisation78

8．4The Hurwitz-Routh Stability Conditions79

8．4．1 The Cubic Equation81

8．4．2 The Equation of Order n82

8．5 Numerical Example83

9．CONSIDERATION OF STABILITY FROM THE OPEN LOOP FREQUENCY RESPONSE FUNCTION85

9．1General Considerations85

9．2The Polar Form of the Frequency-response Function87

9．2．1 Real and Imaginary Parts of the Response Function88

9．2．2 The Logarithmic Form of the Reaponse Function89

9．3 The Generalised Frequency-response Function90

9．4The Nyquist Theory of Stability91

9．4．1 The Number of Roots94

9．5The Degree of Stability94

9．5．1 Phase-advance Technique95

9．6 Gain and Phase Margins97

9．7 Conditionally Stable Systems97

10．THE USE OF THE APPROXIMATE STRAIGHT LINE SEG-MENTED GAIN-FREQUENCY CHARACTERISTICS100

10．1General Relationship between Real and Imaginary Parts of the Frequency-response Function100

10．2 Minimum-phase Networks101

10．3 Relationship between Gain and Phase103

10．4 Area of the log coth ？Curve105

10．5 Approximate Phase Determination106

10．6 The Phase-margin Approach108

10．7 Numerical Example111

11．SPEED CONTROL112

11．1Principle of Speed-control Systems112

11．2 The＂Velodye＂112

11．3 Effect of Loading117

11．4 The Elimination of Droop118

11．5 Measurement of Torque120

11．6 Reducing Brush Ripple123

11．7 Numerical Examples125

12．INTEGRAL CONTROL126

12．1The Principle of Integral Control126

12．2 The Frequency-response Viewpoint126

12．3 The Stability Requirements129

12．4 Proportional,Derivative and Integral Controllers132

13．MEASURING DEVICES AND ERROR DETECTION135

13．1The Form of the Signal135

13．2 Potentiometers for Angular Measurement136

13．3 A．C．Magslip Devices137

13．4 Mechanical Error System using Magslips138

13．5 Inductive Pick-off139

13．6 Capacitive Pick-off139

13．7 Phase-sensitive Rectifiers140

13．8 Measurement of Velocity142

13．9 The Condenser Tachometer143

13．10 A．C．Signal Velocity Generator144

13．11 D．C．Signal Accelerometer146

14．STATIC AMPLIFIERS147

14．1The Meaning of Amplification147

14．2The D．C．Amplifier148

14．2．1 Single-ended Termination150

14．3 Drift in D．C．Amplifiers153

14．4 Power-gain-Band-width Relationship in Multi-stage Amplifiers155

15．ROTARY AMPLIFIERS Ⅰ158

15．1The Use of Rotary Amplifiers158

15．2 The Separately Excited Generator158

15．3 Power-gain-Band-width Relationship159

15．4 The Criterion of Performance161

15．5 The Effect of Feedback162

15．6 The Effect of Commutation on the Frequency Response of the Generator164

15．7 The Shunt-generator Amplifier165

15．8 The Effect of Eddy Currents on the Field Time Constant168

16．ROTARY AMPLIFIERS Ⅱ170

16．1The Ward-Leonard Arrangement170

16．2 The Metadyne171

16．3 The Steady-state Analysis173

16．4 The Separately Excited Machine Analogy of the Metadyne176

16．5 The Amplidyne177

16．6 The Amplidyne with Motor Load178

17．THE SERVO-MOTOR180

17．1The General Function of the Servo-motor180

17．2 The Split-field D．C．Motor181

17．3 Constant Armature Current Arrangements182

17．4 The Two-phase Induction Motor184

17．5 Three-phase Induction Motors185

18．THE STEADY-STATE ACCURACY OF POSITION CONTROL SYSTEMS187

18．1Static Accuracy187

18．2 Two-channel Measurement or Coarse-Fine Systems190

18．3 Disadvantages of the Change-over System193

18．4 The＂Over-ride＂Method194

18．5 Fine Amplitude Limiting195

18．6 Summary of Two-channel Systems198

19．GRAPHICAL PRE-DETERMINATION OF STABILITY FROM THE OPEN-LOOP FREQUENCY RESPONSE LOCUS200

19．1The Need for Stability Pre-determination200

19．2 The Orthogonal Relationship between σ and ω201

19．3 Graphical Construction202

19．4 Aid to Rapid Construction203

19．5 Specific Examples204

19．6 The Use of the Phase and Gain Margins206

20．SOME EFFECTS OF SATURATION ON A SIMPLE SERVO-MECHANISM208

20．1Step Function Response with Initial Velocity208

20．2 Amplitude Limitation in the Error Detector210

20．3 Amplitude Limitation in the Amplifier212

20．4 Approximate Calculations for Limited Amplitude Systems216

20．5 Function Velocity Damping218

20．6 The＂Serme＂System221

20．7 Numerical Example222

21．THE TREATMENT OF NON-LINEARITIES223

21．1The General Second-order Equation223

21．2 The Use of Finite Difference Equations226

21．3 Backlash229

21．4 Omissions230

REFERENCES231

22．1Control Systems231

22．2 Non-linear Mechanics231

REFERENCES TO SPECIFIC POINTS MENTIONED IN THE TEXT232

INDEX235