MEMS Vibratory Gyroscopes: Structural Approaches to Improve Robustness (MEMS Reference Shelf)

✍ Scribed by Cenk Acar, Andrei Shkel

• Publisher: Springer
• Year: 2009
• Tongue: English
• Leaves: 262
• Series: MEMS Reference Shelf
• Edition: 2nd
• Category: Library

✦ Synopsis

MEMS Vibratory Gyroscopes provides a solid foundation in the theory and fundamental operational principles of micromachined vibratory rate gyroscopes, and introduces structural designs that provide inherent robustness against structural and environmental variations. In the first part, the dynamics of the vibratory gyroscope sensing element is developed, common micro-fabrication processes and methods commonly used in inertial sensor production are summarized, design of mechanical structures for both linear and torsional gyroscopes are presented, and electrical actuation and detection methods are discussed along with details on experimental characterization of MEMS gyroscopes. In the second part, design concepts that improve robustness of the micromachined sensing element are introduced, supported by constructive computational examples and experimental results illustrating the material.

✦ Table of Contents

Contents......Page 9
Part I: Fundamentals of Micromachined Vibratory Gyroscopes......Page 13
1.1 The Coriolis Effect......Page 14
1.2 Gyroscopes......Page 15
1.3 The MEMS Technology......Page 16
1.4 Micromachined Vibratory Rate Gyroscopes......Page 17
1.6 Gyroscope Performance Specifications......Page 19
1.7 A Survey of Prior Work on MEMS Gyroscopes......Page 21
1.8 The Robustness Challenge......Page 25
1.9 Inherently Robust Systems......Page 26
1.10 Overview......Page 27
2.1 Dynamics of Vibratory Rate Gyroscopes......Page 28
2.2 Resonance Characteristics......Page 36
2.3 Drive-Mode Operation......Page 39
2.4 The Coriolis Response......Page 40
2.5 Summary......Page 53
3.1 Microfabrication Techniques......Page 54
3.2 Bulk Micromachining Processes......Page 63
3.3 Surface-Micromachining Processes......Page 70
3.4 Combined Surface-Bulk Micromachining......Page 74
3.5 CMOS Integration......Page 75
3.6 Packaging......Page 78
3.7 Summary......Page 82
4.1 Mechanical Structure Designs......Page 83
4.2 Linear Vibratory Systems......Page 84
4.3 Torsional Vibratory Systems......Page 97
4.4 Anisoelasticity and Quadrature Error......Page 103
4.5 Damping......Page 112
4.6 Material Properties of Silicon......Page 117
4.7 Design for Robustness......Page 118
4.8 Summary......Page 120
5.2 Basics of Capacitive Electrodes......Page 121
5.3 Electrostatic Actuation......Page 123
5.4 Capacitive Detection......Page 127
5.5 Capacitance Enhancement......Page 130
5.6 MEMS Gyroscope Testing and Characterization......Page 134
5.7 Summary......Page 149
Part II: Structural Approaches to Improve Robustness......Page 150
6.1 Introduction......Page 151
6.2 Fundamentals of 2-DOF Oscillators......Page 152
6.3 The 2-DOF Sense-Mode Architecture......Page 157
6.4 The 2-DOF Drive-Mode Architecture......Page 166
6.5 The 4-DOF System Architecture......Page 174
6.6 Demonstration of 2-DOF Oscillator Robustness......Page 188
6.7 Summary......Page 193
7.1 Introduction......Page 194
7.2 Torsional 3-DOF Gyroscope Structure and Theory of Operation......Page 196
7.3 Illustration of a MEMS Implementation......Page 202
7.4 Experimental Characterization......Page 208
7.5 Summary......Page 213
8.2 The Approach......Page 214
8.3 Theoretical Analysis of the Trade-offs......Page 220
8.4 Illustrative Example......Page 222
8.5 Summary......Page 231
9.1 Introduction......Page 232
9.2 Comparative Analysis of the Presented Concepts......Page 233
9.3 Demonstration of Improved Robustness......Page 234
9.4 Scale Factor Trade-off Analysis......Page 239
9.5 Future Trends......Page 243
9.6 Conclusion......Page 252
References......Page 253
I......Page 261
Z......Page 262