Pulling a RABIT Out of His Hat

On a well-traveled overpass on the New Jersey Turnpike, 18-wheelers are whizzing by, one after another—so close to the side of the road that, should you be crazy enough to try, you could probably reach out and touch them. There are no concrete safety barriers to hold back the traffic, and yet the bridge inspector remains remarkably unfazed, methodically collecting data on the condition of the pavement and the reinforcements below it. This uncanny sangfroid no doubt derives from the fact that the inspector is a robot, with the unintentionally endearing name of RABIT (Robotics-Assisted Bridge Inspection Tool). 

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Nenad Gucunski, the director of the Infrastructure Condition Monitoring Program at the Center for Advanced Infrastructure and Transportation, which is part of the School of Engineering, surveys the monitors in a mobile command center vehicle, from which he can remotely operate, and interpret the data from, RABIT (Robotics-Assisted Bridge Inspection Tool).

Photography: 

Nick Romanenko

RABIT, which is about the size of a golf cart and looks a little like R2-D2 on cross-country skis, is poised to revolutionize the way we monitor our highways and bridges, and not a second too soon. The 2013 Report Card for America’s Infrastructure, issued by the American Society of Civil Engineers (ASCE), gave a grade of D+ to the nation’s infrastructure as a whole, and this year the American Road and Transportation Builders Association reported that 63,000 bridges—roughly 10 percent of all the spans in America—were “structurally deficient.” The Federal Highway Administration has estimated that the cost of repairing all of these bridges—and many others with less significant defects—would cost taxpayers a staggering $76 billion. We may not be able to afford those repairs, which leaves us with the scary scenario of multiple bridge failures across the country.

Nenad Gucunski has come to the rescue. Like Clark Kent, Gucunski, the chair of the Department of Civil and Environmental Engineering at Rutgers School of Engineering, hides his superpowers behind an amiable façade, but—metaphorically, at least—he’s leaping plenty of tall bridges in a single bound. Gucunski juggles several impressive titles: he is also director of the Infrastructure Condition Monitoring Program at the Center for Advanced Infrastructure and Transportation, also part of the School of Engineering, and was principal investigator on the Automated Nondestructive Evaluation and Rehabilitation System for Bridge Decks, an $18 million joint venture funded by the U.S. Department of Commerce. As the lead of the team that designed and built RABIT for the Federal Highway Admini­stration, he was applying some of the technologies he’d worked on as a doctoral student at the University of Michigan when he was characterizing soil systems.

Before RABIT, the only way to inspect a bridge or the pavement on a highway was to manually remove a series of samples, or cores, from the structure and hope they were representative of the whole. “When you take physical samples of a bridge or pavement, you can only take a finite number and you really don’t get a scan of the entire structure,” Gucunski says. “So you’re always questioning whether you’ve missed deterioration or defects.”

RABIT, on the other hand, can scan an entire bridge or stretch of roadway using a variety of cutting-edge technologies, all of which fall under the rubric of nondestructive testing (NDT). (The goal of NDT, as its name suggests, is to gauge the condition of a structure without causing it physical harm. Unlike its human counterparts, RABIT doesn’t need to dig up the roadway to ascertain its state of health.) In addition to taking high-resolution and panoramic images of the outside of a structure, the robot can peer beneath its surface and detect defects like cracks in concrete, corrosion, and delamination (the failure of composite materials) using ultrasonic surface waves, electrical resistivity, and ground-penetrating radar. Where older methods might yield 10 cores of an overpass, RABIT can take 1,000 measurements.

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Graduate students associated with the School of Engineering help direct traffic on the Warren County Bridge, in Pohatcong Township, New Jersey, where they also assist the operation of RABIT, which surveys the condition of bridges.

Photography: 

Nick Romanenko

That doesn’t just make it more accurate than human inspectors; it also makes it far more economical, a critical consideration at a time of diminishing federal funding. And RABIT is nothing if not efficient.  Gucunski notes that the robot “works three times faster than a team of five NDT specialists,” limiting lane closure times and the highway backups that closings can cause. All of these factors should increase our ability to monitor highway and bridge infrastructure before any signs of potential damage are visible—a strategy Gucunski likens to modern, minimally invasive preventative health care. “Good diagnostics, like MRI and CAT scans, and early intervention help us live longer, higher-quality lives,” he says, noting that efficient monitoring of our infrastructure should do the same for the life spans of our bridges and highways.

For Gucunski, though, RABIT’s greatest advantage may be its ability to keep human beings out of harm’s way. “There are always inherent risks associated with infrastructure testing,” he says. “With robots like RABIT collecting data instead of people, we can virtually eliminate those risks.” In fact, except for the humans who program it with GPS coordinates, RABIT is entirely autonomous. “There’s nobody in the background with a joystick,” says Gucunski.

Over the past year, RABIT has made its debut on highways and bridges in Delaware, Illinois, Maryland, New Jersey, Pennsylvania, and Virginia, with transportation agencies clamoring to use the robot to test the soundness of their structures. In 2014 ASCE awarded Gucunski and his team the engineering society’s esteemed Charles Pankow Award for Innovation. RABIT may soon be joined by a companion robot, developed by Gucunski and his colleagues and designed to repair the problems RABIT detects.  Now in the testing phase, the rehabilitation robot is programmed to locate those defects using GPS coordinates provided by RABIT, then drill a hole and fill it with a special material containing nanoparticles, which allow it to flow into even the finest cracks.

Gucunski describes a scenario in which the two robots work together, RABIT locating the defects and then, within an hour or so, the rehab robot following in RABIT’s path to repair them. He hopes both robots will inspire other researchers to develop similar systems and motivate infrastructure owners (including state departments of transportation) to adopt them. It’s clear that RABIT is already an inspiration. At the team’s first demonstration of the robot in November 2012, Victor Mendez, U.S. deputy secretary of transportation, spoke to the assembled crowd of scientists and Federal Highway Administration dignitaries. “I want you to remember this day,” he told them, duly impressed. “This is the start of a whole new industry.” •

RELATED STORY:

World of Wonders

For 150 years, the School of Engineering has produced
innumerable advances, from weather satellites
to bionic hands to “lumber” made out of recycled plastic.

It was an age of wonders, a time when new technologies vastly expanded on the breakthroughs of a previous century, changing the way human beings lived and worked and educated themselves for the future. The Industrial Revolution reached its apogee in the middle of the 19th century, and it was against this backdrop that, 150 years ago, the Rutgers School of Engineering was born.

In 1857, Vermont congressman Justin Smith Morrill drafted the Morrill Act, which proposed the distribution of land in every state for the purpose of housing a college “related to agriculture and the mechanic arts.” President Lincoln signed the bill into law in 1862. Two years later, Rutgers College prevailed to assume the land-grant mantle in the state of New Jersey, and the college’s board of trustees established Rutgers Scientific School, which offered classes in agricultural sciences, military tactics, and engineering. Of its first 13 graduates, seven were engineers. 

In the ensuing century and a half, they were joined by thousands of young men and women eager to build on the legacy of the Industrial Revolution. In 1914, the Scientific School moved into newly erected Murray Hall and changed its name to the College of Engineering. The school continued to expand and became the School of Engineering, encompassing new disciplines such as materials science as well as chemical and biochemical engineering. Through its research and its talented graduates, it helped to add new wonders to the world.

What is arguably most wondrous about them is their extraordinary variety, a reflection of the expansion of the School of Engineering over time and of engineering itself—into virtually every aspect of modern life. Some of these contributions have been larger than life, like the weather satellites designed by Kenneth R. Johnson ENG’66,’67, who received his B.S. in mechanical engineering from Rutgers in 1966. Others have been smaller than most of us can imagine, like the nanospheres that carry growth factor to injured skin and could revolutionize the treatment of deep-tissue wounds in diabetics, developed by Martin Yarmush, distinguished professor of biomedical engineering at the School of Engineering.  

A good many of them are groundbreaking. Consider the Dextra artificial hand, invented in the 1990s by William Craelius, professor of biomedical engineering. It uses existing nerve pathways to control computer-driven fingers and helped to launch a bionic revolution. Or the recycled-plastic “lumber” that is helping to save forests and keep soda bottles out of landfills, developed in 2011 by Thomas Nosker GSNB’83,’88, principal investigator with AMIPP, a center for advanced polymer materials at Rutgers.

A great many of the school’s innovations have benefited U.S. manufacturers. “What makes Rutgers engineering unique is that it’s part of Rutgers, The State University of New Jersey—which means that it is the engineering school for the state,” notes Thomas Farris, the dean of the school. “And the state of New Jersey has a rich depth of industry and research labs that partner with the school.” Recently, for example, researchers in the Engineering Research Center for Structured Organic Particulate Systems, partnering with New Jersey-based Janssen Pharmaceuticals, devised a method of continuous production for pharmaceutical companies, long dependent on slower and costlier batch processing, and built a $2 million facility at Rutgers in order to perfect the method. 

Although most of the School of Engineering’s contributions trickle down, eventually, to benefit the public, some are designed with the public in mind, like the recent study, led by Janne Lindqvist, assistant professor in the Department of Electrical and Computer Engineering, of the possible use of doodles as hard-to-hijack passwords for smartphones and tablets. 

From satellites to scribbles, the school has long been an engineering innovator. And in the years ahead, it’s likely to continue to lead in innovation and to expand the definition of the field. “As the faculty of the School of Engineering exhibits,” says Farris, “Rutgers’ engineers can do anything.” • 

— Leslie Garisto Pfaff