jason choi professor andrei shkel adam schofield, alex trusov, ozan anac
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Jason ChoiProfessor Andrei Shkel
Adam Schofield, Alex Trusov, Ozan Anac
UCI Micro Systems Laboratory Introduction to Gyroscopes Introduction to Resonators
◦ Basic building blocks of tuning fork gyroscopes Gyroscope Characterization Our Approach to Characterizing Devices
◦ Microvision with a Stroboscopic Algorithm Our System Results
Development of MEMS Inertial Sensors◦ Gyroscopes
Tuning Fork Gyroscope Nuclear Magnetic Resonance Gyroscope
Design Modeling Fabrication Characterization
What is a gryoscope?◦ A device that can measure angular motion or
displacement Applications
◦ Aerospace Inertial guidance systems
◦ Automotive Angular rate sensor
◦ Entertainment Pointing devices, Gaming controller
◦ Medical Vestibular prosthesis
http://mems.eng.uci.edu/
http://www.army.mil
http://www.aa1car.com
Coriolis Effect
Drive Oscillation Coriolis Acceleration
http://www.li-bachman.net
Design and Fabricated by Alex Trusov
http://mems.eng.uci.edu/
3 mm
3 mm
Image taken by Alex Trusov
AC Voltage
Ground
DriveOscillation
3 mm
3 mm
Design and Fabricated by Alex Trusov
Thickness of Each Comb = 6 micons
DriveOscillation
Frequency Response◦ Resonant Frequencies
Maximum Amplitudes
Difficulty◦ Small Micro-Scale Devices (mm)◦ Vibration at High Frequency (kHz)
Thousands of vibrations per second◦ Vibration Amplitudes are small (few microns)
Capacitive Sensing◦ Change in the gap between two electrodes
changes the capacitance.◦ Two electrical terminals are used other than the
driving terminals.
Drawbacks◦ Changes in capacitance are small.◦ Indirect method to measure deflection
Calculation of physical deflection is done by theoretical calculations.
Proven Characterization Method◦ Jasmina Casals
Main Idea◦ Video record the vibration of device◦ Extract vibration amplitudes from the extracted
frames of the video
Advantages◦ Optical, Non-Contact Characterization Method◦ Minimal Control Electronics
Standard Image Limited FPS (frames per second) of video camera
Stroboscopic Technique◦ Solution: Stroboscopic Technique N x (Frequency of Strobe) = Frequency of Vibration N = Positive Integer
Example: If Frequency of Vibration = 30KHz One solution: Frequency of Strobe = 30Hz, N = 1000
Picture by Alex Trusov
0 10 20 30 40 50 60 70 80 90 1000
0.2
0.4
0.6
0.8
1
1.2
Time
Am
plitu
de
Device OscillationStrobe LEDIllumination Point
Computer• Image Pro - Capture Image - Image Processing• MATLAB - Data Processing - Sinusoidal Fit
AC/DC Source
StrobeLight
CCDCamera
MEMSDevice
MicroscopeTrigger Signal
AC/DC Source
CCD Camera
Microscope
MEMS Device StroboscopeComputer
Trigger Source
MEMS Device
Yellow: non-moving part of device Pink: moving part of device
0 50 100 150 200 250 300
38
40
42
44
46
48
50
52
54
Frames
Dis
tanc
e (m
icro
ns)
distance in each frame6.268 X sin (x / 9.507 - 0.1103) + 46.38
0 50 100 150 200 250 300
4
6
8
10
12
14
16
18
Frames (29.97Hz)
Pos
ition
(m
icro
ns)
rdata vs. x3.432 X sin(0.1424x + 3.953) + 10.88
10 20 30 40 50 60
12
14
16
18
20
22
24
Frames
Dis
tanc
e (m
icro
ns)
distance per frame5.765 X sin(x / 4.186 - 2.184) + 17.57
One Example
Freq. of Motion◦ 2460Hz
Freq. of Strobe◦ 55.909Hz◦ N = 44
Amp. of Motion◦ 5.77 ± 0.05 micron
10 20 30 40 50 60
12
14
16
18
20
22
24
Frames
Dis
tanc
e (m
icro
ns)
distance per frame5.765 X sin(x / 4.186 - 2.184) + 17.57
Successful Final Product◦ Measure amplitudes of vibration
Image Pro Macro Programming MATLAB Data Processing
◦ Amplitude Precision (standard deviation of nonmoving object)
± 0.05 microns
◦ Successful Upgrade in Camera Better Images
◦ Optional LabVIEW VI to automatically actuate device and set strobe frequency
Verify Accuracy of Amplitudes with Electrical Capacitance Measurements
Characterize Devices
Continue Project to Characterize 3-D Movement
Said Shokair Professor Andrei Shkel Jasmina Casals Adam Schofield Alex Trusov Ozan Anac IM-SURE Fellows
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