Mackinac Bridge (Sohan Sabnis, Pexels.com)
6 Mar. 2019. Thousands of small sensors are being deployed across the Mackinac Bridge in northern Michigan, one of the world’s longest bridges, to monitor its integrity. The placement of these self-powered sensors builds on a small-scale experimental program begun 3 years ago, by engineering faculty at Michigan State University in East Lansing and Washington University in St. Louis.
A team led by Nizar Lajnef, civil and environmental engineering professor at Michigan State and Shantanu Chakrabartty, professor of electrical engineering at Washington University, is tackling an increasingly vital need for economical, long-term monitoring of civil infrastructure. The large investment in roads, bridges, and other large-scale transportation construction requires continuous surveillance for wear and decay to keep the structures safe and prevent catastrophic consequences.
A key element in any solution is a technology that’s simple to deploy and maintain. Using sensors to monitor roads and bridges is nothing new, but until this project began in 2016, most of those sensors used batteries for power, which need to be replaced. And, in many cases, the sensors were hard-wired to collection stations. Lajnef, Chakrabartty, and colleagues proposed a self-powered sensor that performs the same monitoring functions and transmits data wirelessly.
The researchers chose a high-profile test site, in many respects. The 5-mile long Mackinac Bridge is the world’s third-longest suspension bridge, connecting Michigan’s upper and lower peninsulas across the Mackinac Straits connecting Lakes Michigan and Huron. The bridge’s roadway stands 200 feet above the straits, and supports from 200,000 to more than 600,000 vehicle crossings each month.
The sensors collect their power from vibrations caused by traffic crossing the bridge, with changes in pressure or force measured by the sensors logged and transmitted to data collection stations. As a result, the sensors require no maintenance and have no moving parts. The project, funded by National Science Foundation, includes developing algorithms to identify vulnerabilities in the structure, particularly after man-made or natural disasters. Other algorithms mine historical data to calculate failure probabilities across the structure.
In the first stage of the project, the team installed 20 sensors on the bridge to test their technical feasibility. This new phase expands the number of sensors to 2,000, with the goal of testing large-scale deployment. “Through this large-scale deployment,” says Lajnef in a university statement, “we would show that the system can autonomously monitor the loading experienced by the bridge components, and that the information from the sensors can be collected without significant human intervention and at significantly low cost.”
The next phase also examines data management and use of the information generated by the sensors in maintaining the bridge. “We also will explore,” adds Lajinef, “how the collected data could be used for improved cost-effective, condition-based maintenance of the Mackinac Bridge structural components.”
More from Science & Enterprise:
- Wireless Sensors Monitor Newborns in ICUs
- Institute Developing Phone-Linked Graphene Sensors
- Book Review – The Fifth Risk
- Fast 3-D Method Shapes Objects With Light
- Electronic Tags Assessed to Boost Clinic Care
* * *
RSS - Posts
[…] sensors, particularly for research, telemedicine, and — just this week — monitoring the state of vital infrastructure. But assumed in many of those applications is the ability to easily and inexpensively transmit the […]