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Supervisor’s Foreword |
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Parts of this thesis have been published in the following journal articles: |
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Acknowledgements |
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About the Author |
10 |
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Contents |
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Abbreviations |
14 |
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1 Introduction |
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1.1 State of the Art |
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1.2 Motivation and Problem Statement |
18 |
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1.3 Author's Contributions |
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1.4 Thesis Outline |
20 |
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References |
22 |
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2 Preliminaries |
25 |
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2.1 Mathematical Basis |
25 |
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2.2 Fractional-Order Models |
27 |
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2.2.1 Process Models |
28 |
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2.2.2 Stability Analysis |
28 |
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2.2.3 Time Domain Analysis |
29 |
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2.2.4 Frequency Domain Analysis |
30 |
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2.3 Approximation of Fractional-Order Operators |
31 |
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2.4 Fractional-Order Controllers |
31 |
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2.5 Optimization Methods |
34 |
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2.5.1 Newton-Raphson Method |
34 |
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2.5.2 Nonlinear Least-Squares Estimation Methods |
34 |
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2.5.3 Nelder-Mead Method |
35 |
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2.5.4 Optimization Problems with Bounds and Constraints |
37 |
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References |
39 |
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3 Identification of Fractional-Order Models |
41 |
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3.1 System Identification Fundamentals |
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3.2 Open-Loop Identification in the Time Domain |
43 |
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3.2.1 Parametric Identification |
45 |
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3.2.2 Residual Analysis |
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3.3 Closed-Loop Identification in the Time Domain |
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3.4 Frequency Domain Identification in Automatic Tuning Applications for Process Control |
51 |
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3.5 Conclusions |
58 |
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References |
59 |
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4 Fractional-Order PID Controller Design |
61 |
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4.1 Optimization Based Controller Design |
61 |
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4.2 Gain and Order Scheduling |
66 |
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4.3 Stabilization of Unstable Plants |
68 |
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4.4 Retuning FOPID Control for Existing PID Control Loops |
70 |
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4.5 Control Loop Analysis and Controller Design in the Frequency Domain ƒ |
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4.5.1 Computation of Control System Characteristics |
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4.5.2 FOPID Controller Design |
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4.6 Conclusions |
87 |
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References |
88 |
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5 Implementation of Fractional-Order Models and Controllers |
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5.1 An Update to Carlson's Approximation Method for Analog Implementations |
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5.2 Efficient Analog Implementation of Fractional-Order Models and Controllers |
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5.2.1 Approximation Methods |
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5.2.2 Unified Approach to Fractance Network Generation |
102 |
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5.3 Digital Implementation of Fractional-Order Controllers |
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5.3.1 Discrete-Time Oustaloup Filter Approximation for Embedded Applications |
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5.3.2 FOPID Controller Implementation |
107 |
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5.3.3 FO Lead-Lag Compensator Implementation |
108 |
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5.3.4 Controller Reset Logic |
109 |
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5.4 Experimental Platform for Real-Time Closed-Loop Simulations of Control Systems |
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5.5 Development of a Hardware FOPID Controller Prototype |
111 |
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5.5.1 Atmel AVR Microcontroller Family Based Implementation |
111 |
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5.5.2 STMicroelectronics STM32F407 Microcontroller Family Based Implementation |
115 |
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5.6 Conclusions |
117 |
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References |
118 |
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6 FOMCON: Fractional-Order Modeling and Control Toolbox |
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6.1 Overview of the Toolbox |
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6.2 Identification Module |
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6.3 Control Module |
129 |
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6.4 Implementation Module |
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6.5 Conclusions |
139 |
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References |
141 |
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7 Applications of Fractional-Order Control |
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7.1 Fluid Level Control in a Multi Tank System |
143 |
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7.1.1 Coupled Tanks System |
144 |
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7.1.2 Multi-tank System |
150 |
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7.2 Retuning Control of a Magnetic Levitation System |
155 |
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7.2.1 Identification of the Nonlinear Model of the MLS |
158 |
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7.2.2 FOPID Controller Design for the MLS |
160 |
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7.2.3 Experimental Results |
161 |
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7.3 Control of Ion-Polymer Metal Composite Actuator |
163 |
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7.3.1 Identification of the Actuator Model |
165 |
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7.3.2 FOPID Control |
166 |
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7.3.3 FOINVM Based Control |
168 |
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7.3.4 Hardware Implementation of the Controller |
168 |
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7.4 Conclusions |
175 |
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7.4.1 Multi Tank System |
175 |
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7.4.2 Magnetic Levitation System |
176 |
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7.4.3 IPMC Actuator |
176 |
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References |
178 |
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8 Conclusions |
180 |
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References |
184 |
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