John Wiley & Sons Whole-Angle MEMS Gyroscopes Cover Presents the mathematical framework, technical language, and control systems know-how needed to desi.. Product #: 978-1-119-44188-5 Regular price: $132.71 $132.71 In Stock

Whole-Angle MEMS Gyroscopes

Challenges and Opportunities

Senkal, Doruk / Shkel, Andrei M.

IEEE Press Series on Sensors

Cover

1. Edition June 2020
176 Pages, Hardcover
Wiley & Sons Ltd

ISBN: 978-1-119-44188-5
John Wiley & Sons

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Presents the mathematical framework, technical language, and control systems know-how needed to design, develop, and instrument micro-scale whole-angle gyroscopes

This comprehensive reference covers the technical fundamentals, mathematical framework, and common control strategies for degenerate mode gyroscopes, which are used in high-precision navigation applications. It explores various energy loss mechanisms and the effect of structural imperfections, along with requirements for continuous rate integrating gyroscope operation. It also provides information on the fabrication of MEMS whole-angle gyroscopes and the best methods of sustaining oscillations.

Whole-Angle Gyroscopes: Challenges and Opportunities begins with a brief overview of the two main types of Coriolis Vibratory Gyroscopes (CVGs): non-degenerate mode gyroscopes and degenerate mode gyroscopes. It then introduces readers to the Foucault Pendulum analogy and a review of MEMS whole angle mode gyroscope development. Chapters cover: dynamics of whole-angle coriolis vibratory gyroscopes; fabrication of whole-angle coriolis vibratory gyroscopes; energy loss mechanisms of coriolis vibratory gyroscopes; and control strategies for whole-angle coriolis vibratory gyro- scopes. The book finishes with a chapter on conventionally machined micro-machined gyroscopes, followed by one on micro-wineglass gyroscopes. In addition, the book:

* Lowers barrier to entry for aspiring scientists and engineers by providing a solid understanding of the fundamentals and control strategies of degenerate mode gyroscopes

* Organizes mode-matched mechanical gyroscopes based on three classifications: wine-glass, ring/disk, and mass spring mechanical elements

* Includes case studies on conventionally micro-machined and 3-D micro-machined gyroscopes

Whole-Angle Gyroscopes is an ideal book for researchers, scientists, engineers, and college/graduate students involved in the technology. It will also be of great benefit to engineers in control systems, MEMS production, electronics, and semi-conductors who work with inertial sensors.

List of Abbreviations

I Fundamentals of Whole-angle Gyroscopes 1

1 Introduction 3

1.1 Types of Coriolis Vibratory Gyroscopes 4

1.1.1 Non-degenerate Mode Gyroscopes 4

1.1.2 Degenerate Mode Gyroscopes 5

1.2 Generalized CVG Errors 8

1.2.1 Scale Factor Errors 8

1.2.2 Bias Errors 8

1.2.3 Noise Processes 9

1.3 Overview 11

2 Dynamics 13

2.1 Introduction to Whole-angle Gyroscopes 13

2.2 Foucault Pendulum Analogy 13

2.2.1 Damping and Q-factor 15

2.2.2 Principal Axes of Elasticity and Damping 19

2.3 Canonical Variables 21

2.4 Effect of Structural Imperfections 23

2.5 Challenges of Whole-angle Gyroscopes 25

3 Control Strategies 27

3.1 Quadrature and Coriolis Duality 27

3.2 Rate Gyroscope Mechanization 29

3.2.1 Open-loop Mechanization 29

3.2.2 Force-to-rebalance Mechanization 32

3.3 Whole-angle Mechanization 35

3.3.1 Control System Overview 37

3.3.2 Amplitude Gain Control (AGC) 39

3.3.3 Quadrature Null Loop 41

3.3.4 Force-to-rebalance and Virtual Carouseling 42

3.4 Conclusions 42

II 2-D Micro-machined Whole-angle Gyroscope Architectures 45

4 Overview of 2-D Micro-machined Whole-angle Gyroscopes 47

4.1 2-D Micro-machined Whole-angle Gyroscope Architectures 47

4.1.1 Lumped Mass Systems 47

4.1.2 Ring/Disk Systems 48

4.2 2-D Micro-machining Processes 51

4.2.1 Traditional Silicon MEMS Process 52

4.2.2 Integrated MEMS/CMOS Fabrication Process 53

4.2.3 Epitaxial Silicon Encapsulation Process 53

5 Example 2-D Micro-machined Whole-angle Gyroscopes 57

5.1 A Distributed Mass MEMS Gyroscope - Toroidal Ring Gyroscope

5.1.1 Architecture 58

5.1.2 Experimental Demonstration of the Concept 62

5.2 A Lumped Mass MEMS Gyroscope - Dual Foucault Pendulum Gyroscope

5.2.1 Architecture 68

5.2.2 Experimental Demonstration of the Concept 70

III 3-D Micro-machined Whole-angle Gyroscope Architectures 77

6 Overview of 3-D Shell Implementations 79

6.1 Macro-scale Hemispherical Resonator Gyroscopes 80

6.2 3-D Micro-shell Fabrication Processes 81

6.2.1 Bulk Micro-machinining Processes 82

6.2.2 Surface Micro-machined Micro-shell Resonators 87

6.3 Transduction of 3-D Micro-shell Resonators 94

6.3.1 Electromagnetic Excitation 94

6.3.2 Optomechanical Detection 95

6.3.3 Electrostatic Transduction 95

7 Design & Fabrication of Micro-glassblown Wineglass Resonators 101

7.1 Design of Micro-glassblown Wineglass Resonators 102

7.1.1 Design of Micro-wineglass Geometry 103

7.1.2 Design for High Frequency Symmetry 111

7.2 An Example Fabrication Process for Micro-glassblown Wineglass Resonators

7.2.1 Substrate Preparation 119

7.2.2 Wafer Bonding 119

7.2.3 Micro-glassblowing 120

7.2.4 Wineglass Release 122

7.3 Characterization of Micro-glassblown Shells 123

7.3.1 Surface Roughness 123

7.3.2 Material Composition 125

8 Transduction of Micro-glasblown Wineglass Resonators 129

8.1 Assembled Electrodes 129

8.1.1 Design 129

8.1.2 Fabrication 130

8.2 In-plane Electrodes 135

8.3 Fabrication 137

8.4 Experimental Characterization 138

8.5 Out-of-plane Electrodes 144

8.6 Design 144

8.7 Fabrication 147

8.8 Experimental Characterization 153

9 Conclusions & Future Trends 155

9.1 Mechanical Trimming of Structural Imperfections 155

9.2 Self-calibration 156

9.3 Integration & Packaging 157

Index
Doruk Senkal, PhD, has been working on the development of Inertial Navigation Technologies for Augmented and Virtual Reality applications at Facebook since 2018. Before joining Facebook, he was developing MEMS Inertial Sensors for mobile devices at TDK Invensense. He received his Ph.D. degree in 2015 from University of California, Irvine, with a focus on MEMS Coriolis Vibratory Gyroscopes. Dr. Senkal 's research interests, represented in over 20 international conference papers, 9 peer-reviewed journal papers, and 16 patent applications, encompass all aspects of MEMS inertial sensor development, including sensor design, device fabrication, algorithms, and control.

Andrei M. Shkel, PhD, has been on faculty at the University of California, Irvine since 2000, and served as a Program Manager in the Microsystems Technology Office of DARPA. His research interests are reflected in over 250 publications, 40 patents, and 2 books. Dr. Shkel has been on a number of editorial boards, including Editor of IEEE/ASME JMEMS and the founding chair of the IEEE Inertial Sensors. He was awarded the Office of the Secretary of Defense Medal for Exceptional Public Service in 2013, and the 2009 IEEE Sensors Council Technical Achievement Award. He is the IEEE Fellow.