11/30/2009
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A team of Illinois computer scientists and civil engineers have been working to develop an inexpensive system for continuous and reliable Structural Health Monitoring (SHM) to help protect the estimated $20 trillion civil infrastructure in the US. Computer science professor Gul Agha and civil and environmental engineering professor Billie F. Spencer lead the project.
The team has successfully deployed their system this summer at full scale on the new Jindo Bridge in South Korea, as part of a trilateral collaboration between the University of Illinois, the University of Tokyo, and the Korean Advanced Institute of Science and Technology. The deployment is the largest of its kind for civil infrastructure to date, and is the first dense deployment of a wireless sensor network on a cable-stayed bridge. The project demonstrates the suitability of the Illinois approach and the Illinois-developed software for full-scale, continuous, autonomous structural health monitoring.
According to government data, annual infrastructure costs amount to between 8-15% of the GDP for most industrialized nations. With recent bridge collapses in the US, much attention has been focused on the declining state of the aging and poorly monitored bridges and roads.
The ability to continuously monitor the integrity of civil infrastructure in real time offers the opportunity to reduce maintenance and inspection costs, while providing increased safety to the public.
“Manual inspection of bridges costs millions of dollars, is relatively unreliable, and can only be carried out infrequently. Some real world deployments show that dense arrays of sensors can provide detailed information about the state of civil infrastructure,” said Illinois civil engineering professor Billie F. Spencer. “However, the enormous expense of installing traditional monitoring systems has significantly limited deployment.”
To address this issue, the Illinois team is testing a system that employs dense arrays of wireless smart sensors designed to record and transmit complex, high-fidelity data cheaply and efficiently. The team’s technology employs concurrent and distributed real-time processing to overcome the limitations inherent in traditional centralized approaches.
The collaboration has resulted in new hardware and software systems for the continuous and reliable monitoring of civil infrastructure, with the most recent release of an open source toolsuite containing a library of services for, and examples of, SHM applications.
Illinois computer scientists working on the project have led the development of a Service-Oriented Architecture (SOA) that lends itself to further expansion, customization, and development of applications for SHM. It provides complete applications that facilitate common tasks throughout the design, testing, deployment, and monitoring of the SHM system, while utilities offer a set of basic testing and debugging commands to be included with existing applications. The SHM Services Toolsuite includes utilities for resetting nodes remotely, listing the nodes within communication range of the local node, testing radio communication performance, and changing the radio channel and power for local and remote nodes. The Illinois civil engineers have developed specialized hardware to accurately detect high-frequency vibrations and strain in structures. The hardware plugs into embedded computers and works in conjunction with the SOA for SHM.
“The traditional centralized approach for SHM is not feasible with moderate to large numbers of sensors: tremendous amounts of data must be sent to such a central station, requiring expensive, difficult-to-install wired networking and introducing a single point of failure,” said Illinois computer science professor Gul Agha, the lead CS collaborator on the project. “Our research in distributed SHM using wireless sensor networks overcomes these problems and promises a robust, significantly lower-cost, safer alternative to traditional structure inspection techniques.”
In combination, the Illinois-developed system of sensors and software create an integrated framework that can easily be utilized by most civil engineers without requiring an extensive background in computer science.
Illinois researchers working in the project include computer science professor Gul Agha and civil and environmental engineering professor Billie F. Spencer, Jr., computer science PhD students Parya Moinzadeh, Kirill Mechitov, and Civil and Environmental Engineering PhD students Shinae Jang, Hongki Jo, Jennifer Rice (PhD 09), Robin Kim, Sung-Han Sim.
For more information on the Illinois Structural Health Monitoring Project and the Structural Health Monitoring Services Toolsuite software, visit http://shm.cs.uiuc.edu.