Embed Size (px)
DESCRIPTION
"Lectio Praecursoria" of the doctoral dissertation entitled "Application-Driven Data Processing in Wireless Sensor Networks" at Aalto University School of Electrical Engineering, Helsinki, Finland
Citation preview
Application-DrivenData Processing
in Wireless Sensor Networks
Maurizio Bocca
Department of Automation and Systems TechnologyAalto University School of Electrical Engineering, Helsinki,
Finland
2
What is a Wireless Sensor Network?
Maurizio Bocca – Lectio Praecursoria – 4.11.2011
A WSN is a wireless network consisting ofspatially distributed autonomous devices
using sensors and/or actuators tocooperatively
monitor and/or operate into the environment
3
WSNs architecture
Maurizio Bocca – Lectio Praecursoria – 4.11.2011
INTERNET
4
The building blocks of a WSN
Maurizio Bocca – Lectio Praecursoria – 4.11.2011
limited resources
SENSOR
NODE
5
Compared to wired systems, WSNs are:
Maurizio Bocca – Lectio Praecursoria – 4.11.2011
Less expensive(no cabling, reduced maintenance)
Easier to be installed(nodes in large numbers, in critical locations)
More robust to failures and harsh environmental conditions
6Maurizio Bocca – Lectio Praecursoria – 4.11.2011
7Maurizio Bocca – Lectio Praecursoria – 4.11.2011
WirelessAutomation
StructuralHealth
Monitoring
IndoorSituation
Awareness
8
Human Adaptive Mechatronics in wireless automation
• HAM aims at improving the performance of human-machine systems: by adapting to the individual
characteristics of the human operator by providing assistance to improve the
execution of the tasks
• Human operator ≈ controller• Wireless communications
introduce random time delays
INSTABILITY
Maurizio Bocca – Lectio Praecursoria – 4.11.2011
9
Wireless Joystick Control System
Maurizio Bocca – Lectio Praecursoria – 4.11.2011
Filter bad actions taken by the human operator
Smoothen the control commands to minimize load swinging…
…also in the case of packet losses
10Maurizio Bocca – Lectio Praecursoria – 4.11.2011
WirelessAutomation
StructuralHealth
Monitoring
IndoorSituation
Awareness
11
Structures need constant care!
Maurizio Bocca – Lectio Praecursoria – 4.11.2011
I-35W Mississippi Bridge
31.7.2007
I-35W Mississippi Bridge
1.8.2007
SHM aims at accurately assessing the stability ofcivil infrastructures
12
WSNs for SHM: centralized approach
Maurizio Bocca – Lectio Praecursoria – 4.11.2011
accurate time synchronization
reliable data transfer
MODE SHAPES
NATURAL FREQUENCIESand DAMPING RATIOS
13
WSNs for SHM: distributed approach
Maurizio Bocca – Lectio Praecursoria – 4.11.2011
limited computational resources
DAMAGE DETECTIONand LOCALIZATION
REDUCED LATENCYand POWER CONSUMPTION
14Maurizio Bocca – Lectio Praecursoria – 4.11.2011
WirelessAutomation
StructuralHealth
Monitoring
IndoorSituation
Awareness
15
Knowing what is going on so that you can figure out what to do next
Maurizio Bocca – Lectio Praecursoria – 4.11.2011
• Perception of the elements in the environment
• Comprehension of their meaning• Projection of their status in the near
future
DECISIONMAKING
ACTION!
16
Speaker identification
Maurizio Bocca – Lectio Praecursoria – 4.11.2011
• Sensor nodes limitations: Sampling frequency Length of the signals Low Signal-to-Noise ratio
From “Helsingin Sanomat”8.11.2008
17
Device-free people tracking
Maurizio Bocca – Lectio Praecursoria – 4.11.2011
-80
-60
-40
RS
SI [
dB
m]
-5
5
15
25
35
Ale
rt m
agn
itu
de
0 5 10 15 20 250
10
20
30
40
Time [s]
Var
ian
ce [
dB
m]
RSSIi,j
fi,j
Alerti,j
2short
2long
distributed processing
18
In conclusion, the thesis presents:
• Data processing methods• Protocols and architectures
optimized for the requirements and characteristics of the considered application domains
Maurizio Bocca – Lectio Praecursoria – 4.11.2011
Thank you!
CO-DESIGN IMPROVESTHE SYSTEM PERFORMANCE
WSNs CAN GREATLY ENHANCEOUR COMPREHENSION
OF THE SURROUNDING ENVIRONMENT
