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Wireless Sensor Networking and Control:
Trends and Applications
Chih-Yu Wen
Department of Electrical Engineering
Graduate Institute of Communication Engineering
National Chung Hsing University
3
Today’s Wireless Themes
Ubiquitous communication with focus on interoperability, plug-and-play, IP
Self-organizing networks and low power High quality AV streaming Positioning & Location
8
The Disappearing Computer (1/2)
More and more processors are not on desktops Processors in cars, in cellular telephones, in toys Even the computer itself can “dissolve” into an
entertainment system - digital TV screen and speakers - CPU on shelf - wireless keyboard on lap
10
Home Computer of Tomorrow
Flat wall screens for TV/computer in many rooms Connected to an out-of-sight CPU by LAN Multiple speakers embedded in/around screen for
3D sound effects Screen can act as an (open) window
when not in use Natural input interface -- voice/pointing (no
keyboard needed)
13
House as a Web Site (1/2)
Processors in various appliances All networked (locally, and to wireless hub) Appliances can communicate with outside world - Security system calls you or police - “Smart recycling bin” orders more food Can log onto your house site to control them - Turn heat up - Turn coffeemaker on (already a reality)
15
Cars of Tomorrow
GPS to know position Wireless connection to obtain traffic conditions Sensors:
- distance to cars / people / obstacles
- indoor/outdoor temperatures
- road traction Screen to show sensor readings / maps Radio used for warnings / directions Automatic controls based on sensor readings
23
Sensors for/in the Body (1/2)
Digital jewelry: DCPU in watch, speaker in an earring, camera in glasses
Scenarios: (salesmen) Identifies person approaching, whispers their
name, position to you (repair trainee) Identifies machine parts, projects visual
instructions on glasses Assumes powerful vision/voice recognition Embedded microsensors
Track vital signs, blood levels For at-risk people: sick, old, mountain climbers
Chronic Obstructive Pulmonary Disease (4/4)
28Ming-Feng Wu and Chih-Yu Wen, “A Novel Shuttle Walking Model Using Networked Sensing and Control for Chronic Obstructive Pulmonary Disease: A Preliminary Study,” The 6th International Conference on Pervasive Computing Technologies for Healthcare - PervasiveHealth 2012 , San Diego, CA, USA.
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Ambient Intelligence (1/2)
Intelligent environments of all kinds: Highways
- Where are the traffic jams? Airports
Who is entering/leaving high-risk areas? Large high-rise office complexes
- Are there problems with heat/AC anywhere? Oceans
Is a Tzunami on its way? People
33
Pervasive Computing (1/3)
Computation in service of our needs: Personal: Entertainment, daily activities, travel,
house monitoring Companies: Work efficiency, building monitoring Scientific/medical: remote training / diagnosis,
monitoring oceans Governments: security, automatic gathering of
statistics
35
Pervasive Computing (3/3)
Computing made easy
- Interaction through natural modalities
- Interaction during natural activities Computing made invisible
- Hidden in objects of everyday use
- Distributed
- Embedded in environments
The computing paradigm for 21st century
36
Sensors
Essential part of pervasive computing Computation
A small embedded computer with limited processing power and memory
Communication: LAN, Wireless, Infrared / sound
Sensing Temperature, pressure, magnetic field, noise levels, chemicals,
etc.
37
So Why Sensor Networks?
A Bridge to the Physical World Environmental Protection Health Care Smart Environments Industrial Process Control Military Battlefield Awareness Disaster Recovery
41
The 802 Wireless Space
Data Rate (Mbps)
Ran
ge
ZigBee802.15.4 802.15.3
802.15.3a802.15.3c
WPAN
WLAN
WMAN
WWAN
WiFi802.11
0.01 0.1 1 10 100 1000
Bluetooth802.15.1
IEEE 802.22
WiMaxIEEE 802.16
IEEE 802.20
(Reproduced from ZigBee Alliance)
42
Can existing systems satisfy design goals?
P2P: DHT Gnutella
Data Correlation Vs DecentralizationN
one
Tem
pora
lS
patia
l
Centralized Hierarchical Fully Distributed
WebCaches
CentralizedData
Collection
Geo-SpatialData Mining, Streaming
Media (MPEG-2)
WirelessSensor Networks
Exp
loit
ed
Data
C
orr
ela
tion
Degree of Decentralization
43
Embedded Networked Sensing Apps Micro-sensors, on-board
processing, wireless interfaces feasible at very small scale--can monitor phenomena “up close”
Enables spatially and temporally dense environmental monitoring
Embedded Networked Sensing will reveal previously unobservable phenomena
Seismic Structure response
Contaminant Transport
Marine Microorganisms
Ecosystems, Biocomplexity
44
Imagine (the CASA version)…. (1/4)Imagine (the CASA version)…. (1/4)
Noontime: all clear DCAS systems monitor 3D
winds, 0 to 3 km high “clear-air” winds provide
basis for pollutant monitoring, migratory bird tracking
Dense network of radars - distributed collaborative adaptive sensing (DCAS)
45
Imagine…. (2/4)Imagine…. (2/4)
2PM: solar ground heating wind convergence zones form DCAS pattern detection
algorithms detect convergence
data archiving begins radars automatically tasked to
sample moisture fields around convergence zone
models generate predictions, provided to local emergency managers for planning
46
Imagine…. (3/4)Imagine…. (3/4)
3PM: severe weather Clouds, precipitation develop in
convergence several zones DCAS radars adjust, provide fine-
scale measurements, precipitation estimates in critical areas
skies to south clear, but DCAS systems monitoring 3D temperature, moisture to assess potential for future thunderstorms
rotational signatures cause nearby radars to enter tornado tracking mode
location, intensity, projected path provided to community, state organizations, industry. Because of 2PM predictions, officials prepared
spawned tornado destroys two radars, nearby DCAS radars reconfigure
47
Imagine…. (4/4)Imagine…. (4/4)
5PM: storms move south to Houston
.. as predicted by continuously monitoring DCAS systems
rainfall begins, DCAS systems reconfigure to map precipitation at fine resolution
DCAS measurements feed hydrological models
local, state, organizational emergency response teams are in action and prepared well in advance of flood waters..
52
Security
HVAC
Lighting Control
Access Control
Lawn & Garden
Irrigation
Asset Mgt
Process Control
EnvironmentalEnergy Mgt
Patient monitoring
Fitness monitoring
Security
HVAC
AMR
Lighting Control
Access Control
TV
VCR
DVD/CD
RF Remotes
ZigBeeWireless Control that
Simply Works
RESIDENTIAL/LIGHT
COMMERCIAL CONTROL
CONSUMER ELECTRONICS
PC & PERIPHERALS
INDUSTRIALCONTROL
PERSONAL HEALTH CARE
BUILDING AUTOMATION
Chart Copyright ZigBee Alliance 2004
WSN Application Markets
54
Sensor Hardware
Location finding system Mobilizer
Power unit
Analogy to digital
converter
Sensor
Processor
Storage
Transcevier
Sensing unit
Processingunit
Power generator
Figure 1-1 The component of a sensor node
55
Embedded Sensor Nets: Enabling Technologies
Embedded Networked
Sensing
Control system w/Small form factorUntethered nodes
Exploit collaborativeSensing, action
Tightly coupled to physical world
Embed numerous distributed devices to monitor and interact with physical world
Network devices to coordinate and perform higher-level tasks
Exploit spatially/temporally dense, in situ/remote, sensing/actuation
無線感測網路的運作無線感測網路的運作分成三大要項:
(1) 感測行為 (2) 嵌入式元件 (3) 網路架構。
在嵌入式系統的發展之下,我們可透過許多無所不在的感測元件來監控周遭的環境,
利用網路技術來協調與整合感測資訊, 將無線感測網路應用於日常生活之中。
56
60
Core Challenges
Infrastructure-less Energy Efficiency Wireless Communication Data Fusion Dynamics
Adaptive and Self-Configuring network adjustment and re-tasking
Robustness and Fault Tolerance
61
Limited Computation and Data Storage
Sensor design Multi-objective sensors single (a few)-objective sensors.
Cooperation among sensors Data aggregation Data interpretation
62
Sensor Nets: New Design Themes Self-configuring systems
adapt to unpredictable environment dynamic, messy (hard to model), environments
preclude pre-configured behavior Leverage data processing inside the network
collaborative signal processing achieve desired global behavior with localized
algorithms (distributed control) Long-lived, unattended, untethered, low duty
cycle systems energy a central concern
67
Application-specific Constraints
Material Constraints Bio-Compatibility Inconspicuous Imitative to environment Detect-proof: e.g. stealth flight
Secure Data Communications Regulatory Requirements –such as FDA
71
Discussions
Unique solution to all applications exists? Most important considerations in designing:
Cost? Resource allocation? Manageability? Timeliness? Re-tasking? … Scalability? Millions of sensor nodes?
Next generation sensor nets?
72
Tendency of Sensor Networks
Scaling Up Sensor Networks [Zang, 2004]
1-1000 1000-10M >10M
Number of embedded devices
Tomorrow
Today
Cen
tral
ized
Con
trol
dis
trib
uti
on
Dec
entr
aliz
ed
Traffic light control
Networked health careSmart
buildings
Networked transportation
Automated factories
Office computing Asset tagging
and tracking
74
A Sensor Application at NCHU
• Si represents the location of sensor node i. (i: 1 ~ 9) • BS is the location of the base station (control center).
83
感測器濕度變化
62
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17:52:48 18:00:00 18:07:12 18:14:24 18:21:36 18:28:48 18:36:00 18:43:12 18:50:24時間
溼度
3802380438053809
感測器溫度變化
30
30.05
30.1
30.15
30.2
30.25
30.3
30.35
30.4
30.45
17:52:48 18:00:00 18:07:12 18:14:24 18:21:36 18:28:48 18:36:00 18:43:12 18:50:24 18:57:36
時間
溫度
3802380438053809