A traditional bridge inspection typically involves a bridge inspector going out to the site and manually recording defects and problem areas of cracks, spalls and delaminations. Today, transportation officials are using drones to capture real-time data from a tablet device thanks to a team of researchers at Michigan Tech Research Institute (MTRI).
Led by research scientist Colin Brooks, remote sensing experts are using drones to access hard-to-reach locations, compile a database and explore defects of aging bridges using a 3D app. The technology can help cut costs and reduce risk to staff during bridge inspections, according to an MTRI news release.
More than 54,000 of the 612,677 bridges in the U.S. have at least one key element that is in poor or worse condition, according to a 2018 bridge deficiency report conducted by the Federal Highway Administration.
“We need to know if we can get from point A to point B,” Brooks says. “An important component of mobility is being able to understand whether or not the transportation system you’re looking at can effectively move goods and people based on the condition of the infrastructure.”
The researchers are using several types of drones to conduct bridge inspections. The unmanned vehicles fly in 20-minute runs below 400 feet to capture data. They are outfitted with photogrammetry and thermal imagery gear that picks up nuances "beyond what the human eye sees." The release says the 3D assessment allows inspectors to collect and record problem areas and upload field data and notes into a bridge management system from a tablet device.
“We focused a lot on being able to create objective and repeatable data to help assess bridges,” Brooks says. “Drone surveys don’t have to be expensive. We run drones that cost less than $10,000 to do nearly all of our work.”
Brooks says the team is working with several companies and is also helping Michigan Department of Transportation (MDOT) to implement the 3D bridge app and drone-based condition bridge inspection into their day-to-day workflow.
Over time, researchers will continue to help make sure the drones, remote sensing and apps are verified and cost-effective for users.
“New sensors, new platforms seem to come online several times a year — so how do we take advantage of that rapid innovation and hardware and make them available on a practical basis?” Brooks says. “Somebody has to do the testing to make sure the tech collects what’s needed and that’s part of the niche we fill."