“It’s a blast. I get to work with toy robots and lasers.”
In the summer of 2011, UNO received a three-year, $937,000 grant from the Office of Naval Research to design and build a new type of robotic eel that is capable of operating in shallow water environments where Navy personnel could be at risk. The man in charge of the project is Brandon Taravella, an assistant professor in UNO’s School of Naval Architecture and Marine Engineering who earned bachelor’s, master’s and doctoral degrees from UNO. The nearly $1 million boon was the first grant of his young career, and it came at an eventful time in his life.
“It was pretty exciting,” Taravella says. “(My wife and I) were actually in the hospital. We just had our second son and the next day I got an email on my phone (confirming he had received the grant). It was like all at once.”
The grant gave new life to an aquatic swimming theory originally completed by Taravella’s former adviser, William Vorus, professor emeritus in the School of Naval Architecture and Marine Engineering. Taravella and his team are trying to prove Vorus’ theory, which involves a swimming motion that has very low drag and high efficiency. Vorus theorized that if the eel swims with a defined shape, this type of propulsion will have no wake.
“Our problem is that you can’t point your finger at an eel and say ‘swim like this,’” Taravella says. “So that’s why we’re resorting to a robot because we want that ideal shape.”
According to Taravella, scientists have studied the hydrodynamics of eels and others have built eel robots — mostly for fun — but no one else has ever merged the two together and analyzed the hydrodynamics of this ideal eel shape. In the first year of the project, Taravella and his team —comprised of graduate students Baker Potts, Jacob Todd and Charles Rogers, and staff engineer Ryan Thiel — built a prototype of the eel, made up of a series of battery-powered links covered in a water-tight, blue latex skin. The researchers began testing the eel in UNO’s 125-foot towing tank, located in the College of Engineering Building. They videotaped the eel as it was towed through the water at different speeds; then they dissected the video, frame-by-frame, to compare the eel’s motion to the theoretical motion they are trying to achieve.
The project received a major boost in May 2012, when UNO was awarded a $280,000 grant from the Department of Defense to purchase a sophisticated machine which uses a series of lasers and cameras that will allow researchers to visualize the wake, or lack of wake, produced by the eel.
“If we didn’t have the equipment, we were actually pursuing other options like taking it off campus,” Taravella says. “Now we don’t have to. There’s probably only two other towing tanks in the country that have a similar piece of equipment.”
In the second year of the project, the engineers will continue to modify the eel, including making it a remotely-operated device, while trying to prove whether Vorus’ wakeless propulsion theory is correct. In the future, Taravella says he wants the eel to be fully autonomous so that it doesn’t need an operator at all— the eel will simply use sensors to find its way. He also says he’d like it to be able to maneuver so that it can rise, dive and steer.
Recent changes in naval warfare have created a greater demand for devices like the robotic eel because they can operate in shallow water areas such as rivers and coastline. One important mission is intelligence, surveillance and reconnaissance, which sometimes involves monitoring and data collection in harsh or dangerous conditions. As a result, the Navy has a strong interest in developing unmanned underwater vehicles, according to Taravella. These vehicles can carry sensors, cameras, audio devices and weather equipment into perilous environments without being detected. The benefit of UNO’s eel is, if it can achieve wakeless swimming, it will be both more energy efficient and, theoretically, more difficult to detect. The eel must also be compact enough to be useful to the military.
“We are looking for a length that is easy for one person to handle so a Navy SEAL can just get up to a certain point and just reach over the boat and put it in the water,” Taravella says. “We don’t want anything that’s too heavy or too bulky.”
The original Office of Naval Research grant that funded the robotic eel is for three years, but Taravella says the project has the potential to lead to much more long-term research. He says getting the robot to swim in a controlled environment would be one milestone, but doing it in an uncontrolled environment would be an even greater challenge.
The project draws on various disciplines within the UNO College of Engineering, including naval architecture and marine engineering; electrical engineering; and mechanical engineering. The process of building and testing the eel is one that involves frequent encounters with breakthroughs and roadblocks. And as painstaking as the research can be, Taravella is having the time of his life—as though he were working on a Hollywood blockbuster.
“It’s a blast,” he says. “I get to work with toy robots and lasers.”