Researchers to Test Water Drone for Bridge Inspections

Image courtesy of Florida Atlantic University.

A research team at Florida Atlantic University’s (FAU) College of Engineering and Computer Science has received a $187,000 grant from the Florida Department of Transportation (FDOT) to develop autonomous waterborne vehicles that can assist in bridge inspections.

Although the technology is still in the early stages of development, the long-term aim is that the unmanned surface vehicles (USVs) could be used by the agency to make bridge inspectors’ work safer and more efficient, according to GovTech.com. FDOT currently uses a variety of methods and equipment to inspect and test the sections of the state’s 11,451 bridges that are above water level. However, the only method that can be used to check the sub-surface areas is divers, who search for cracks, erosion, damage and defects that might impact on a bridge’s safety. A high percentage of Florida’s bridges are in corrosive salt water, and divers frequently experience problems with low visibility from silt, sediment, debris and algae, weed or other plant matter.

The team from FAU’s Department of Ocean and Mechanical Engineering have experience in USV research, and won second place at the eighth annual International RoboBoat Competition in Virginia Beach, Va., according to GovTech.com.

Two months into a 12-month project, the team has upgraded a watercraft used for past research projects with a new propulsion system that allows the craft to maintain its position and heading during a bridge scan. The next phase of research will be to equip the craft with an acoustic scanning system that functions in a similar manner to a LiDAR (Light Detection and Ranging) system. By installing the scanner on a mount that can tilt and pan, researchers expect to obtain 3D models of the parts of the bridge that are below the water.

The current vessel is equipped with an automatic control system that uses GPS and a compass to direct the craft toward programmed waypoints, and can keep it steady in a variable current, allowing scanning to take place. Once the acoustic scanner is equipped in September, the team will begin testing the craft’s scanning capabilities on three bridges that have been recommended by FDOT for their diverse representation of the state’s bridge environments.

“These sorts of technologies aren’t really meant to replace wholesale divers and so forth,” the FAU project’s principal investigator, Karl von Ellenrieder, told GovTech.com. “It’s to make their jobs easier, and it’s another tool that can help them do their jobs better. The way I view it is, you would take a vehicle like this and it would allow you to more rapidly scan bridges, and then when you detect a problem, send out a diver to verify the problem through testing. If you’re going to send divers out into strong currents with nasty snakes and stuff, it’s better to have a good sense there’s a problem before you do that.”