294 Presentation SensorActuator Network for Damage Detection

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294 PresentationSensor/Actuator Network for
Damage Detection

• Presented
• by
• Kajari GhoshDastidar

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The Main Idea

• The authors have presented a working
• model of an automated and distributed
• damage detection system using a wireless
• sensor-actuator network.

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The Main Idea

• How can such a system detect damage in
  structures?

• Frequency shift method
• Sensors nodes analyze frequency response
• Locally extract modes
• Collaboratively decides

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The Main Achievements

• Accomplishments
• A damage detection scheme is described that uses
  extremely low transmission bandwidth, and is
  shown to be effective in detecting damage in a
  simulated structure

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The Main Achievements

• Achievements
• Uses decentralized local excitation
• High resolution measurement of response
• Efficient performance of detection algorithms
• Low duty cycle operation

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The Challenges

• Overcome the drawbacks of a traditional
  Structural Health Monitoring (SHM) system.
• Local damage detection
• Global assessment using low-res measurements
• Dependent on ambient excitation
• Understanding how this technique applies to
  structural engineering.
• Research infrastructures must be developed.

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The Challenges

• We are working with sensors !!
• Wireless
• Battery operated
• Small form factor
• Computing devices

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Pictures

• A lab test bed with a mobile exciter

Viterbi School of Engineering, University of
Southern California, Los Angeles CA 90089.
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Innovation

• Buildings are constructed using concrete mixed
  with several tens of thousands of embedded sensor
  devices as well as (a possibly smaller number of)
  low power local exciters.
• This network of sensors will be able to
  continuously monitor a structure, trigger alarms
  that identify the onset of damage, precisely
  pinpoint the location of damage and also provide
  a long-term history of ambient stresses imposed
  on the structure.