Researchers from Drexel University’s College of Engineering have developed a wireless sensor system powered by solar energy that can monitor bridge deformation continuously. This system has the potential to alert authorities when bridge performance significantly deteriorates, making it a crucial safety measure and aiding in prioritizing repair and maintenance efforts. The American Society of Civil Engineers reports that over 46,000 bridges in the United States are considered to be in poor condition, highlighting the importance of such a system.
The research team, consisting of Ivan Bartoli, Mustafa Furkan, Fei Lu, and Yao Wang, unveiled their system in a recent edition of the IEEE Journal of Emerging and Selected Topics in Industrial Electronics. Bartoli, who heads the Intelligent Infrastructure Alliance in the College of Engineering, emphasizes the urgent need for continuous monitoring of critical infrastructure, not only to prevent failures but also to efficiently prioritize maintenance and replacement.
With more than 40% of the country’s 617,000 bridges over 50 years old, regular inspections are necessary. The current practice involves visual inspections and monitoring only those bridges identified as “problematic structures.” However, the number of bridges requiring attention is increasing. Drexel’s wireless displacement sensor system provides a solution by utilizing a solar photovoltaic cell, a displacement potentiometer for measuring deformation, and a monitoring interface transceiver. These components are mounted on the bridge to measure and transmit deformation information as vehicles pass over it.
The displacement potentiometer, a lightweight and robust device, is attached to the bridge’s girder to measure its movement and detect changes in deformation patterns that may indicate structural problems. The system operates on solar power and a backup battery, eliminating the need for extensive wiring. Multiple potentiometers can be installed on a bridge, allowing for the integration of various sensors to monitor acceleration, tilt, displacement, and other parameters. This comprehensive data collection provides a holistic view of bridge health.
One of the main advantages of this system is the elimination of costly and vulnerable wiring, making it more affordable and easier to install. Additionally, the wireless platform enables the simultaneous reading of different sensor types, enhancing its capabilities. The power supply for the system was designed and optimized by a team of electrical engineers from Drexel’s Department of Electrical and Computer Engineering. It includes a large-capacity lithium-ion battery and a 10-watt photovoltaic cell, ensuring uninterrupted power supply even during adverse weather conditions.
The team conducted extensive testing in lab and outdoor environments, including winter conditions, to validate the system’s endurance and durability. The goal is to provide an affordable and resilient sensor array that requires minimal maintenance and can continuously monitor bridges, not just those in poor condition. By collecting extensive data, the system establishes a baseline for each bridge’s normal structural behavior and can promptly detect any unexpected changes.
The researchers aim to refine the system by incorporating additional sensor types and determining the power supply’s full lifespan. While the system is currently ready for deployment, further testing will ensure its reliability and effectiveness. With continuous and reliable monitoring, the researchers envision safer and more efficient management of bridge infrastructure, capturing data on overloads, structural deformations caused by heavy loads, and environmental factors like wind and temperature changes.
Source: Drexel University