Roadmap Motivation for a network of wireless sensor nodes Applications Structural Health Monitoring Traffic Control Health care Pipeline monitoring Precision Agriculture Underground Mining
Roadmap • Motivation for a Network of Wireless Sensor Nodes • Applications ▪ Structural Health Monitoring ▪ Traffic Control ▪ Health Care ▪ Pipeline Monitoring ▪ Precision Agriculture ▪ Underground Mining
Structural Health Monitoring notivation Events: On august 2, 2007, a highway bridge unexpectedly collapsed in innesota Nine people were killed in the event Potential causes: wear and tear, weather, and the weight of a nearby construction project In fact, the bbc reported (august 14, 2007)that China had identified more than 6, 000 bridges that were damaged or considered to be dangerous These accidents motivate wireless sensor networks for monitoring bridges and similar structures
Structural Health Monitoring ▪ Motivation ▪ Events: ▪ On August 2, 2007, a highway bridge unexpectedly collapsed in Minnesota ▪ Nine people were killed in the event ▪ Potential causes: wear and tear, weather, and the weight of a nearby construction project ▪ In fact, the BBC reported (August 14, 2007) that China had identified more than 6,000 bridges that were damaged or considered to be dangerous ▪ These accidents motivate wireless sensor networks for monitoring bridges and similar structures
Structural Health Monitoring Motivation: Traditional inspections Visual inspection everyday Labor-intensive, tedious, inconsistent and subjective Basic inspections >at least once a year Detailed inspection at least every five years on selected bridges Special inspections according to technical needs The rest require sophisticated tools expensive bulky and power consumIng
▪ Motivation: ▪ Traditional inspections: ▪ Visual inspection ➔ everyday ▪ Labor-intensive, tedious, inconsistent, and subjective ▪ Basic inspections ➔ at least once a year ▪ Detailed inspection ➔ at least every five years on selected bridges ▪ Special inspections ➔ according to technical needs ▪ The rest require sophisticated tools ➔ expensive, bulky, and power consuming Structural Health Monitoring
Local and global inspections Local inspection techniques focus on detecting highly localized imperceptible fractures in a structure Requires a significant amount of time the disruption of the normal operation of the structure Global inspection techniques aim to detect a damage or defect that is large enough to affect the entire structure Researcher have been developing and testing wireless sensor networks as global inspection techniques
Local and Global Inspections ▪ Local inspection techniques focus on detecting highly localized, imperceptible fractures in a structure ▪ Requires: ▪ a significant amount of time ▪ the disruption of the normal operation of the structure ▪ Global inspection techniques aim to detect a damage or defect that is large enough to affect the entire structure ▪ Researcher have been developing and testing wireless sensor networks as global inspection techniques
Wisdenhttp://enl.uSc.edu/projects/wisden/ First prototype to employ wsn for monitoring structural health Installing a large scale wired data acquisition system may take several weeks and is quite expensive First deployment-for conducting seismic experiments on an imitation of a full-scale 28 X 28 square foot hospital ceiling the overall weight which the ceiling supports is approximately 12,000 pounds Second deployment 25 nodes(a tree topology and a 16 bit vibration card a high-sensitive triaxial accelerometer is attached to the vibration card designed for high-quality, low-power vibration sensing the task of the network was to reliably send time-synchronized vibration data to a remote sink over a multi-hop route NACK hop-by-hop scheme
Wisden ▪ First prototype to employ WSN for monitoring structural health ▪ Installing a large scale wired data acquisition system may take several weeks and is quite expensive ▪ First deployment - for conducting seismic experiments ▪ on an imitation of a full-scale 28×28 square foot hospital ceiling ▪ the overall weight which the ceiling supports is approximately 12,000 pounds ▪ Second deployment ▪ 25 nodes (a tree topology) and a 16 bit vibration card ▪ a high-sensitive triaxial accelerometer is attached to the vibration card ▪ designed for high-quality, low-power vibration sensing ▪ the task of the network was to reliably send time-synchronized vibration data to a remote sink over a multi-hop route ▪ NACK ▪ hop-by-hop scheme http://enl.usc.edu/projects/wisden/