Transcript No Slide Title

DARPA
MTO
MEMS
SMART DUST
K. Pister, J. Kahn, B. Boser
(UCB)
S. Morris
(MLB)
SMART DUST
Goals
• Autonomous sensor node (mote) in 1 mm3
• MAV delivery
• Thousands of motes
• Many interrogators
• Demonstrate useful/complex integration in
1 mm3
SMART DUST
COTS Dust
GOALS:
• Create a network of sensors
• Explore system design issues
• Provide a platform to test Dust components
• Use off the shelf components
SMART DUST
COTS Dust - RF Motes
• Atmel Microprocessor
• RF Monolithics transceiver
• 916MHz, ~20m range, 4800 bps
• 1 week fully active, 2 yr @1%
N
W
E
S
2 Axis Magnetic
Sensor
2 Axis Accelerometer
Light Intensity
Sensor
Humidity Sensor
Pressure Sensor
Temperature Sensor
SMART DUST
COTS Dust - Network Simulation
Cheap platforms --> Lots of nodes -->
Network challenges!
SMART DUST
Message Diffusion (McLurkin)
•
3.5
3
•
2.5
2
1.5
•
1
0.5
Each mote checks all it’s received
transmissions for the one with the
maximum value
The mote then rebroadcasts it
with a lower value
The result is a gradient pointing
towards the signal source.
0
-0.5
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
Number Of Motes=200
Communications Range=.5
SMART DUST
Edge Detection using Min/Max
•
4.5
4
•
3.5
3
•
2.5
2
1.5
•
1
0.5
0
-0.5
0
0.5
1
1.5
2
2.5
3
3.5
4
•
1. Ask each or your
neighbors how many motes
they can see.
2. Find the minimum and
maximum of these numbers
3. Share these minimum and
maximum numbers with all
your neighbors.
4. When all your neighbors
have the same min.max info
as you, compare your local
neighbor count to this info.
5. Turn red if you are lonely
Number Of Motes=500
Communications Range=.5
SMART DUST
Gradient Directed Communication
6
6
6
5
5
5
4
4
4
3
3
3
3
2
2
2
2
1
1
1
1
0
0
0
0
6
5
4
-1
-1
-1
0
1
2
3
4
5
6
0
1
2
3
4
5
-1
0
5
6
5
1
2
3
4
5
6
6
5
5
4
4
3
3
4
4
3
3
2
2
2
2
1
1
1
1
0
0
0
0
-1
•
•
•
•
-1
-1
0
1
2
3
4
5
0
1
2
3
4
5
0
1
2
3
4
5
0
1
2
3
4
5
-1
0
1
2
3
4
5
Number Of Motes=150
These gradients can be used to direct
Communications Range=1
transmissions towards a single source
Messenger Agents (the light blue dots) transmit
themselves to motes with higher message levels
This provides the minimum number of hops to get to a
central destination
SMART DUST
Centroid Location
•
•
5
4
•
3
•
2
Find edges
Diffuse pheromone
from the edges inward
Find the lowest
concentration using
Min/Max sharing
If you have the lowest
concentration, turn
yellow
1
0
-1
-0.5
0
0.5
1
1.5
2
Number Of Motes=500
Communications Range=.8
2.5
3
3.5
4
4.5
SMART DUST
Mote Position Estimation
•
•
•
Give GPS receivers to some motes and callthem “BasisMotes”. Ask
them to turn gray.
Each BasisMote diffuses it’s own pheromone throughout the group
The position of any other mote can be estimated from the levels of
basis pheromones present.
SMART DUST
Network Growing
•
•
•
Number Of Motes=128
Communications Range=1
Since diffusion
directed
communication
already minimizes
number of hops,
whatever are we
going to optimize?
We can use
division of labor to
optimize power
(time)
Certain motes are
responsible for
communications to
the hub and others
are responsible for
sensing
SMART DUST
COTS Dust - Optical Motes
Laser mote
• 650nm laser pointer
• 2 day life full duty
CCR mote
• 4 corner cubes
• 40% hemisphere
SMART DUST
CCR Interogator
Top View of the Interrogator
Filter
CCD Camera
Polarizing
Beamsplitter
Quarter-wave
Plate
Lens
0.25% reflectance
on each surface
Frequency-Doubled
YAG Green Laser
Beam
Expander
45o mirror
SMART DUST
Video Semaphore Decoding
Diverged beam @ 300m
Shadow or full sunlight
Diverged beam @ 5.2 km
In shadow in evening sun
SMART DUST
Video Semaphore Decoding
Diverged beam @ 300m
Shadow or full sunlight
Diverged beam @ 5.2 km
In shadow in evening sun
SMART DUST
1 Mbps CMOS imaging receiver
10mW, 1mrad
Optical
Filter Collection
Lens
64x64
CMOS
Imager
10cm
5mm
200m
Photosensor
CRC Check
SIPO Shift
Local Bus Driver
Register
2 km
Field of View
of Single Pixel
Signal Processing
A/D Conversion
Off Chip
Bus Driver
Pixel Array
SMART DUST
Optical Communication (vs. RF)
• Pro:
•
•
•
•
•
•
low power
small aperture
spatial division multiplexing
high data rates
LPI/LPD
baseband coding
• Con:
• line of sight
• atmospheric turbulence
SMART DUST
Turbulent Channel
Physical Origin of Beam Scintillation
Maximum-Likelihood
Sequence Detection Algorithm
1
4
2
1
3
2
Eddies
1
3
2
1 3
2
1
3
2
2
Communication through Turbulent Atmosphere
3
1
1 3
2
v
1
3
2
1
3
3
1
Laser
To Signal
Detection
Receiver
1
22
33
1 3
2
1
1
3
2
1
1
23
4
1
2
3
0
1
0
Eddies
SMART DUST
1
Micro Mote - First Attempt
SMART DUST
2D beam scanning
AR coated dome
lens
Steering Mirror
laser
CMOS ASIC
SMART DUST
•
•
•
Open loop control
Insensitive to disturbance
Potentially low power
Normalized beam position
6-bit DAC Driving Scanning Mirror
0.8
0.6
0.4
0.2
0
10
20
30
Time (seconds)
40
SMART DUST
Power and Energy
• Sources
• Solar cells
• Thermopiles
• Storage
• Batteries ~1 J/mm3
• Capacitors ~1 mJ/mm3
• Usage
• Digital control: nW
• Analog circuitry: nJ/sample
• Communication: nJ/bit
SMART DUST
’01 Goal
SMART DUST
MAV Delivery
Built by MLB Co.
• 60 mph
• 18 min
• 1 mi comm
SMART DUST
Dust Delivery
• Floaters
• Autorotators
• solar cells
• Rockets
• thermopiles
MOTE
• MAVs
SMART DUST
Micro Flying Insect
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•
•
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ONR MURI/ DARPA funded
year 1 of 5 year project
Dickinson, Fearing (PI), Liepmann, Majumdar,
Pister, Sands, Sastry
Heavily leveraged on Smart Dust
SMART DUST
Applications
• DoD
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•
•
•
•
•
Battlefield sensor networks
Sensor mine-fields, burrs and fleas
Traffic mapping
Captured terrain surveillance
Bunker mapping
...
• Civilian
• High speed/low power IRDA
• Interactive virtual ballet
• ...
SMART DUST
The
(somewhat)
Virtual Keyboard
SMART DUST
Data from ACC-glove
SMART DUST
Conclusion
• Cubic inch motes off-the-shelf, ~$100
• Dec ’99: 100 node network in Soda/Cory
• Desperately need intelligent software
• Millimeter-scale motes
• Dec ’00: first working prototypes
• Don’t have a clue what we need in software
SMART DUST