《SERVOMECHANISMS AND REGULATING SYSTEM DESIGN VOLUME II》

1MEASUREMENT TECHNIQUES1

1．0 INTRODUCTION1

1．1 INFORMATION DESIRED1

1．2OPEN-LOOP CHARACTERISTICS3

Transient Response Method4

Frequency Response Method12

1．3CLOSED-LOOP FREQUENCY RESPONSE CHARACTERISTICS19

Frequency Response C/R20

Error Response,E/R21

Response to Output Disturbances,E/UL22

1．4 CLOSED-LOOP TRANSIENT RESPONSE MEASUREMENTS23

1．5FREQUENCY RESPONSE FROM TRANSIENT RESPONSE MEASUREMENTS25

Frequency Response from Transient Response to a Unit Step Input26

Frequency Response Derived from Transient Response to a Unit Impulse29

Frequency Response from Transient Responseto a Bounded Input Signal33

2INFLUENCE OF INPUT CHARACTERISTICS ON CONTROL SYSTEM DESIGN36

2．0 INTRODUCTION36

2．1CHARACTERISTICS OF IDAELIZED INPUT38

Magnitude of Idealized Input Function and Its Derivatives38

Abnormal Transient Input Conditions39

Steady-State Sinusoidal Inputs40

Forms of System Configuration40

2．2REPRESENTATIVE IDEALIZED INPUT FUNCTIONS43

Inputs to Servomechanisms Tracking a Target Flying a Straight Line44

Position Input Requirements of a Contour Follower Servomechanism49

2．3SERVOMECHANISM ERROES OR ARBITRARY INPUT FUNCTIONS51

Differential Equstion Approach52

Equivalent Sinusoidal Input Approach59

2．4EXTRANEOUS SIGNALS65

Simplified Approach to Noise Problem67

Statistical Approach to the Noise Problem69

2．5SELECTION OF SERVOMECHANISM CHARACTERISTICS CONSIDERING NOISE AND DESIRED INPUTS79

Example Illustrating Method of Comparing Noise and Systematic Errors Present in Servomechanism Output82

2．6 APPLICATION OF SERVOMECHANISM CHARACTERISTIC SELECTION METHODS TO COMPLEX SERVOMECHANISM SYSTEMS85

2．7 RADAR NOISE MEASUREMENTS86

3SELECTION OF CONTROLLED SYSTEM POWER ELEMENT WITH PROPER RATING89

3．0 INTRODUCTION89

3．1LOAD CHARACTERISTICS90

Load Inertia90

Friction Load91

Shock or Other External Loads91

Unbalance Loads91

Maximum Velocity,Acceleration,and Travel of Load91

Duty Cycleand Time Rating91

Other Limitations91

3．2 REFERRING LOAD AND MOTOR TO A COMMON BASE92

3．3TOROUE,APEED,AND POWER REQUIREMENTS OF LOAD95

Torque96

Speed96

Power97

3．4DETERMINATION OF POWER ELEMENT TORQUE,SPEED,AND POWER RATING101

Equivalent Sinussoidal Duty Cycle102

3．5 MOTOR-LOAD GEAR RATIO FOR MINIMUM RMS MOTOR TORQUE109

3．6 INFLUENCE OF GEAR RATIO ON MOTOR TIME CONSTANT111

3．7 EFFECT OF GEAR MESH RATIOS ON EFFECTIVE MOTOR INERTIA114

4NETWORKS FOR OBTAINING DESIRED ATTENUATION-FREQUENCY CHARACTERISTICS119

4．0 INTRODUCTION119

4．1 STABILIZING MEANS AVAILABLE120

4．2DESCRIPTION OF CHARTS121

Network Grouping Arrangement121

Identification of Elements136

Choice of Network Configuration Represented136

4．3 CIRCUIT TECHNIQUES FOR SIMPLIFYING ANALYSIS138

4．4 AIDS IN USE OF CHARTS FOR SPECIFIC PROBLEMS141

4．5 USE OF NETWORKS IN FEEDBAOK LOOP145

4．6 PARALLEL-TYPE NETWORES146

5AMPLIFIER DESIGN150

5．0 INTRODUCTION150

5．1 AMPLIFIER DESIGN CONSIDERATIONS151

5．2 PROBLEMS ENCOUNTERED IN D C AMPLIFIERS153

5．3DRIFTS DUE TO POWER SUHRLY VARIATIONS155

Drifts in a Simple Triode155

Drifts in a Cathode Follower157

5．4DRIFTS DUE TO COMPONENT VAHIATIONS159

Component Variations in Triode Amplifier159

Component Variations in Cathode Follower161

5．5CIRCUITS FOR REDUCING DRIFTS IN D-C AMPLIFIERS164

Compensation for Variations in Positive Supply164

Compensation for Variations in Negative Supply165

Circuits for Reducing the Effects of Heater Temperature Variations166

Modulator-Demodulator Type Amplifiers171

5．6 D-C LEVEL CHANGER172

5．7 USE OF AMPLIFIERS TO TRANSFORM NETWORKS174

5．8DETECTORS AND MODULATORS178

Phase-Sensitive Detectors178

Modulators182

5．9 LIMTT CTRCUITS184

6ALL ALTERNATING-CURRENT SERVOMECHANISM OPERATION187

6．0 INTRODUCTION187

6．1 COMPONENTS OF FREQUENCIES PERSENT IN ALL A-C SERVOMECHANISM SYSTEMS189

6．2 REQUIREMENTS FOR ALL A-C STABILIZING SIGNALS192

6．3BRIDGED-T AND PARALLEL-T NETWORKS FOR A-C STABILIZATION196

Bridged-T Network197

Parallel-T Network201

6．4 EFFECT OF CHANGES IN THE CAREIER FREQUENCY205

6．5 A-C TACHOMETER FOR STABILIZATION209

6．6 CONCLUSIONS212

7LINEARIZATION OF NON-LINEAR ELEMENTS FOR SMALL DEPARTURES214

7．0 INTRODUCTION214

7．1LINEARIZATION OF THE EQUATIONS OF NON-LINEAR SERVOMECHANISM ELEMENTS215

Principle of Small Increments216

7．2MOTOR TIME CONSTANTS FOR NON-LINEAR MOTOR CHARACTERISTICS218

Split-Field Serles Motor221

Two-Phase A-C Motor224

D-C Shunt Motor with Field Control225

7．3JET ENGINE CONTROL CHARACTERISTICS227

Description of Problem228

Data from Engine Performance Characteristics231

7．4LINEARIZATION OF CONTROL SYSTEMS WITH TIME-VARIABLE PARAMETERS234

Network Approach to Problem236

7．5 CONCLUSION240

8LINEARIZATION OF NON-LINEAR ELEMENTS FOR LARGE DEPARTURES241

8．0 INTRODUCTION241

8．1DESCRIBING FUNCTION FOR SINUSOIDAL INPUTS242

Saturation245

Deadband251

Relay with Dead Zone and Hysteresis257

8．2STABILITY OF NON-LINEAR SYSTEMS261

Formulation of Stability Problem263

Complex Plane Representation265

Attenuation and Phase Margin versus Frequency Representation267

Gain versus Phase Repressntation269

System Performance269

General Comments273

8．3SATURATION EFFECTS ON POSTTION CONTROL SYSTEMS274

Illustrative Conditions of Saturated Operation274

Effect of Saturation on Performance during Synchronizing276

Series-Stabilized Unconditionally Stable System,K=200279

Series-Stabilized Conditionally Stable System,K=500283

Feedback-Stabilized Lower-Gain System,K=200288

Feedback-Stabilized Higher-Gain System,K=500293

Feedback-Stabilized System with Two Motor Time Constants299

Conclusions Regarding Effect of Saturated Elements299

8．4BACKLASH IN POSITION CONTROL SYSTEMS WITH LOAD RESONANCE301

Description of System301

System Design Parameters303

Basis for Stability Analysis306

Effect of Load Mechanical Resonant Frequency309

Effect of Motor to Load Inertia Ratio JM/JL309

Effect of Loading Damping Ratio,ζ313

Comparison of Load and Motor Feedback313

Analog Computer Results313

Compatison of anglog Computer and Frequency Response Analysis Results319

Concltusions of Backlash Stusy321

8．5RELAY-TYPE SERVOMECHANISMS322

Deseription of System323

System Stability and Performance323

8．6 VELOCTITY-PHASE DIAGRAMS327

8．7 CONCLUDING REMARKS332

9APPLICATION OF NON-LINEAR ELEMENTS TO CONTROL SYSTEMS333

9．0 INTRODUCTION333

9．1NON-LINEAR ELEMENTS IN SYSTEMS WITH INDEPENDENTLY VARYONG PARAMETERS333

Winding Reel Application334

Autopilot Systems336

Computer Systems341

9．2 NON-LINEAR ELEMENTS IN STETRMS WITH A WIDE RANGE OF PERFORMANCE REQUIREMENTS344

9．3NON-LINEAR ELEMENTS FOR AOOOMFLISHING CHANGER IN SYSTEM PERFORMANCE345

Variable Gain346

Variable Time Constant349

Comparison of Synchronizing Response of Adjustable Gain and Adjustable Time Constant Systems351

9．4NON-LINEAR ELEMENTS TO IMPROVE SYSTEM SYNCHRONIZATION357

Clamping357

Saturation and Feedback361

Other Methods363

9．5CONCLUSION TO VOLUME Ⅱ364

Components365

Analytical Work365

Computers and Simulators366

System Integration367

Authors＇Note367

BIBLIOGRAPHY360

INDEX377