November 13, 2007

$1 million grant fuels wireless sensor research

by Tim Crosby

max yen

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CARBONDALE, Ill. — The city water meter reader's job got easier a couple years ago as wireless sensors made it possible to gather the readings from a remote location, such as a vehicle driving down the street.

But that remote data collection technology can't hold a candle to what researchers at Southern Illinois University Carbondale are working to create.

University scientists from several fields, working through the SIUC Materials Technology Center, recently received $1 million from the Federal Highway Administration's Intelligent Transportation Systems program to create a network of Internet-based wireless sensors and databases that can provide near real-time data and analysis on the structural soundness of transportation infrastructure, such as a bridge.

Shing-Chung "Max" Yen, director of the Materials Technology Center, said the technology combines an integrated sensor network with wireless technology and powerful analysis tools that potentially would improve transportation safety and efficiency. Engineers also could apply such systems to many other situations, such as security systems and environmental monitoring.

"You want to get this information quick, even when you are away from the area," Yen said. "If we develop this technology the right way, it will benefit many areas. These are global concepts and there are many things we can do. There are no boundaries."

The three-year project, which the University is also committing $1 million to in terms of faculty release time and other subsidies, will involve several faculty from various engineering and science-related departments including civil and environmental engineering, chemistry and biochemistry and electrical engineering. Both undergraduates and students pursuing advanced degrees also will have the opportunity to play a role in the research, Yen said.

The team first will focus on creating and applying the system to a bridge. They will use a footbridge on campus to test ideas and eventually will work with the Illinois Department of Transportation to wire an actual vehicle bridge somewhere in the area.

The idea involves placing different kinds of sensors that can detect variables such as stresses, elongation, deformation and rotations, at key points on the structure. The researchers will connect the sensors to wireless transmitters, each set up as their own IP address, which will then send data to an Internet server off-site. The researchers will download that data to a Web site for analysis.

The sensors must not only transmit data about how the structure is behaving, but must also crosscheck each other to ensure the data is reliable. For example, the sensors should show the effects of damage to a bridge at the point of damage, but sensors further away might also validate those effects by signaling the bridge's structure is compensating for that damage elsewhere.

Only then do the sensors become a true network and really begin telling the story of the structure's health, creating what Yen calls the structure's "signature."

One of the biggest challenges the researchers face, however, is fast, accurate analysis of what promises to be a huge amount of incoming data. Without that, all the data is mostly useless.

A sizeable portion of the researchers' work, therefore, will go into building databases containing various parameters against which they can compare the new, incoming data from sensors. Because such databases are largely non-existent, the researchers will build their own. They will use data they can apply from existing sets — such as corrosion data from the auto industry — along with their own predictions about how the bridge structure should react under different circumstances, based on past experience, actual examples and computer models.

Such databases might include scenarios for how a bridge might react if it is damaged, if it receives faulty repairs that change its dynamics, or how those dynamics change as the bridge simply gets older, Yen said.

"You have to be knowledgeable enough to know what your data means," Yen said. "You have to be able to tell what is reliable data and what is not. So you have to have a lot of databases.

"If an emergency comes up, we're looking for quick assessments. We don't have time to do computations. If you can do that, there is still a chance to minimize the potential catastrophe."

Yen foresees a time when many bridges have their own performance record database on file that can be used, updated and consulted as the structure ages and undergoes repairs and modifications. Depending on how successful they are, Yen said the sensor network coupled with the powerful and layered databases will allow for much quicker diagnosis of structural problems with a bridge than civil engineers using traditional methods can perform. At the very least, the system would better indicate when a thorough, traditional evaluation is called for, making bridge inspections more efficient overall.

Eventually, such analysis may result in more efficient design of bridges, which may sometimes be overbuilt to ensure safety over the estimated life of the bridge. Yen said, however, an overbuilt bridge may not be safer in the long run and this research may indicate better ways to build safer, longer-lasting bridges.

Infrastructure is simply the selected proving ground for the new system. It also could be applied to any number of environments including security, such as homeland security or law enforcement, or environmental monitoring.

Security is an obvious possibility. Such a network could work in concert with ultra-sensitive sensors that "sniff" the air for chemicals emitted by methamphetamine labs or explosives, keeping the public and law enforcement out of harm's way. Ling Zang, assistant professor of chemistry and biochemistry at SIUC, is working on such sensors and he will work on the project as well, Yen said.

People also could place the system in environmentally sensitive areas, such as in or around public water supplies, to give constant remote feedback and analysis and quickly warn and pinpoint contamination.

Yen hopes the project also will help SIUC maintain an updated curriculum for engineering students, keeping them well prepared for the workplace after graduation.

"This project will allow us to exercise a real job situation and can help us influence the potential placement of our students," Yen said. "It will also help us with our curriculum. The engineering industry is changing and we also need to be changing."


Building a network – Shing-Chung "Max" Yen, center, director of the Materials Technology Center at Southern Illinois University Carbondale, works with graduate and doctoral students on the electronics needed to create a network of Internet-based wireless sensors and databases that can provide near real-time data and analysis on the structural soundness of transportation infrastructure, such as a bridge. Yen recently received $1 million from the Federal Highway Administration's Intelligent Transportation Systems program for the research, which engineers also might apply to security systems and environmental monitoring. Students working with Yen are Adam Miller, left, a senior in electrical engineering from Minier; Oliver Yang, a doctoral student in electrical engineering from Taipei, Taiwan; and Chris Williams, right, a junior in civil engineering from West Frankfort.

Photo by Russell Bailey