Professor David A. Horsley Hemispherical Resonator Gyroscope

Professor David A. Horsley Hemispherical Resonator Gyroscope

Micromechanical Gyroscopes
Professor David A. Horsley
Hemispherical Resonator Gyroscope
Diamond Hemispherical Shells
Researchers: Amir Heidari, Hadi Najar, Hseuh-An Sean Yang, Gerardo Jaramillo, Parsa Taheri
Frequency Match
High-Q Diamond DETF
8
Objectives:
1  10
Realize 3D micro shell resonators 1  10
7
1  10
6
1  10
5
1  10
4
Fabricate highly symmetric hemispheres using a combination precision machining and traditional MEMS micromachining techniques
Silicon
Quartz
SiGe
Diamond
1 μm
3
1  10
3
1  10
Process Flow
4
1  10
5
1  10
6
1  10
7
1  10
Microcrystalline Diamond (MCD)
8
Theoretical TED-limited Q vs. frequency
Parameters:
f = 5 Hz
Pressure: 4.3e-8 bar
Excitation: Electrostatic/Probe
Sensing: LDV
Investigate polycrystalline diamond as high Q‐factor structural material
1  10
Ring-Down Test
= 180 mSec
Parameters:
Vac: 7.5e-5 Torr
fn = 24.420 KHz
Q = 10,000
Double-Ended Tuning Fork (DETF)
Integrated Electrodes
Polysilicon electrodes
250 m
1 mm
Disk Resonator Gyroscope
Diamond DETF sample frequency response
showing Q = 81,646 and fn = 473.303kHz
Resonator
Q
factor
matches
thermoelastic damping limit predicted
using experimentally measured thermal
conductivity
Researchers: Sarah Nitzan, Jason Su, Mo Li
0.6 mm DRG - Setup
Mode-Matching
Tuning and quadrature null:
•
Bias Voltage: 15 V
•
Sense-Axis tuning: 0 V
•
Drive-Axis tuning: 9 V
•
Quadrature Null: 4.5 V
After Mode-Match:
ARW, Bias-Stability & Scale Factor
Q = 55,000
•
Bandwidth = 4 Hz
2 mm DRG and Ring w/ Integrated Electronics
DRG
Nonlinearity at large
drive amplitudes:
•
Tuning Ring Gyro:
Ring
85
40.0
• increases noise
• leads to instability
DRG Modes:
On-Chip Electronics:
Fall 2012
©2012 University of California
Prepublication Data March 2013
Berkeley Sensor & Actuator Center