Active, Hybrid, and Semi-active Structural Control: A Design and Implementation Handbook

Preface ix

1 Introduction 1

1.1 General 1

1.2 Basic Principles 4

1.3 State-of-the-Practice 5

1.3.1 Hybrid Mass Damper Systems 6

1.3.2 Active Mass Damper Systems 9

1.3.3 Semi-active Damper Systems 11

1.3.4 Semi-active Controllable Fluid Dampers 14

1.4 Implementation-Related Issues 18

1.4.1 An Overview 20

1.5 Organization 23

2 Hardware Description 27

2.1 Introduction 27

2.2 Active Control Force Generation System 28

2.2.1 General 28

2.2.2 Electrical Power Driven Mechanism 31

2.2.3 Hydraulic Power Driven Mechanism 32

2.3 Measuring Equipment 36

2.3.1 General 36

2.3.2 Position Transducers 37

2.3.3 Velocity Transducers – Tachometers 38

2.3.4 Accelerometers 39

2.3.5 Force Transducers 40

2.4 Signal Interface System 41

2.4.1 General 41

2.4.2 Conditioning System 42

2.4.3 Filtering System 43

2.4.4 Monitoring System 50

2.4.5 Fail-Safe Limitation Detection System 52

2.4.6 Signal Communication and the Remote Activation System 56

2.5 Digital Control System 57

2.5.1 General 57

2.5.2 Data Acquisition/Conversion System 58

2.5.3 Control Command Calculator 61

2.6 Case Study 62

2.6.1 Hydraulic Devices with a Control Console 64

2.6.2 Measuring Equipment 72

2.6.3 Custom-Designed Interface Drawer 72

2.6.4 Digital Control System 102

2.6.5 Integration Issues 104

3 Control Software Implementation 121

3.1 Introduction 121

3.2 Practical Considerations 122

3.2.1 General 122

3.2.2 Modeling Errors and Spillover Effects 122

3.2.3 Time Delay and Time Lag 123

3.2.4 Structural Nonlinearities 123

3.2.5 Uncertainties in Structural Parameters 124

3.2.6 Limited Number of Sensors and Controllers 124

3.2.7 Discrete-Time Control Features 125

3.2.8 Reliability 125

3.3 Digital Control System (Software) 126

3.3.1 General 126

3.3.2 Quantization Issues 127

3.3.3 Sampling Issues 131

3.3.4 Access to Hardware Issues 133

3.3.5 Saturating and Scaling Issues and the Overflow Effect 140

3.3.6 Digital Control with a DSP 142

3.4 Appropriate Design Morphology 143

3.4.1 General 143

3.4.2 Interactive Configuration Module 143

3.4.3 System Clock Set-up Module 143

3.4.4 Analog I/O Module 145

3.4.5 Real-Time Adjustment Module 145

3.4.6 Channel On/Off Identification Module 146

3.4.7 Error Detection and the Correction Module 147

3.4.8 Measurement Manipulation Module 148

3.4.9 Engineering Unit Scaling Module 149

3.4.10 Control Algorithm Module 149

3.4.11 System Response Monitoring and the Reporting Module 150

3.4.12 Data Storage and the Communication Module 150

3.4.13 Fail-Safe Multi-protection Module 150

3.4.14 Smooth Start-Up/Shut-Down Module 151

3.4.15 Remote Control Module 152

3.5 Case Study 152

3.5.1 Interactive Configuration Group 153

3.5.2 Signal Processing Group 154

3.5.3 Control Algorithm Group 164

3.5.4 Fail-Safe Protection Group 175

4 Theoretical and Practical Control Techniques 181

4.1 General 181

4.2 Continuous-Time Optimal Direct Output Feedback 182

4.3 Effect of Time Delay 184

4.3.1 System Stability Analysis 185

4.3.2 Time Delay Effect 187

4.4 Discrete-Time Control Analysis and Design 194

4.4.1 Discrete-Time Systems 194

4.4.2 Time Delay Effect 195

4.4.3 Optimal Direct Output Feedback Control Gains 197

4.4.4 Frequency Domain Analysis Issues 200

4.4.5 Time Domain Analysis Issues 201

4.5 Analytical Simulations of Discrete-Time Control 204

4.5.1 General 204

4.5.2 Optimal Direct Output Feedback Control Gains 204

4.5.3 Stability Analysis and Time Delay Compensation 206

4.5.4 Time Domain Simulation Using Earthquake Input 212

4.6 Case Study 214

4.6.1 Analytical Model 214

4.6.2 Optimal Control Gains and Stability Analysis 221

4.6.3 Time Domain Verification Using Wind Excitation 226

5 Control Performance Verification 235

5.1 Introduction 235

5.2 Real-Time Structural Simulator 236

5.2.1 Theoretical Background 236

5.2.2 Hardware and Software Set-up 238

5.2.3 Calibration and Validation Processes 239

5.3 Real-Time Control Verification of the Hybrid/Active Mass Damper Model 247

5.3.1 Experimental Set-up 247

5.3.2 Calibration of the Sampling Period 248

5.3.3 Identification of the delay time 249

5.3.4 Experimental Verification of the Integrated System 250

5.4 Case Study 255

5.4.1 Calibration of the Sampling Period 255

5.4.2 Identification of the Delay Time 256

5.4.3 Experimental Verification of the Integrated System 257

6 Summary 263

6.1 Directions of Future Development 266

References 269

Author Index 279

Subject Index 281