Howie Choset actually doesn’t like snakes all that much. However, that hasn’t stopped the CMU Robotics Institute professor from developing a series of lifelike snake robots to perform dangerous tasks — that can now operate underwater.
“Me personally, I’m afraid of snakes,” says Choset. “I don’t want to touch one. I don’t want to be near one. I know when I was a grad student, an office mate had one as a pet and I had nightmares because of it.”
But Choset realized more than 25 years ago that the shape and form of a snake is perfect for the development of robots that are both small enough and strong enough to sneak into confined spaces.
“One implication that’s near and dear to my heart is urban search and rescue, where these robots can serve as tools to help rescue workers locate victims who are in collapsed rubble,” says Choset. “Three years ago, we did send our snake robots to Mexico City, at the invitation of the Mexican Red Cross, to help support search and rescue operations after their terrible earthquake that they had.”
A version of the snakebot also famously slithered up Jimmy Fallon’s leg on NBC’s “The Tonight Show,” as Choset showed off its climbing abilities. Fallon was startled, to say the least.
Most recently, CMU’s Biorobotics Lab designed the snakebot to travel underwater so that it can inspect battle damage to naval ships’ hulls, submarines, and structural flaws in offshore oil rigs. It’s a partnership with the Hazelwood-based Advanced Robotics for Manufacturing Institute and the U.S. Department of Defense.
“Right now, you have Navy divers going underwater, swimming around with a rope and a flashlight, trying to assess the damage,” says Choset. “This is very time-consuming and a little dangerous.
“So what we want to do is give every naval ship one of these snake robots, and then somebody like you or me can throw those robots overboard and drive it around as if we’re playing a video game or steering a three-dimensional car.”
The robot’s official name is Hardened Underwater Modular Robot Snake (HUMRS). Aside from naval and military applications, these mechanical reptiles could inspect underwater pipes for damage or blockages or check any liquid-filled tank for breakages. The robot’s flexibility gives it lots of different ways to approach a challenging movement.
“The end result is that an underwater robot snake can squeeze around corners and into small spaces where regular submersibles can’t go,” says Nate Shoemaker-Trejo, a mechanical and mechatronics engineer in the Biorobotics Lab.
Working in water presents challenges a robot doesn’t face on land. On land, you have something solid to push off from. Underwater, the robot has to writhe in a way that allows it to swim, which is very different than slithering forward on a hard surface.
“Underwater, every motion has a counter-motion,” explains Choset.
The robot also has to “see” via video, in sometimes murky water, which is another challenge.
The snakebot is 3.5 inches in diameter and 3-4 feet long. The project began in July 2020, and snakebot was swimming in CMU’s pool by March. The key to the speed of the project is the robot’s modularity, using components from previous iterations of the snake robot.
“Instead of building the same snake robot from scratch each time, we decided to build modules,” says Choset. “And then we just attach the modules together to form a snake.”
Choset leads HEBI Robotics, a spin-off company from the Biorobotics Lab. It may end up being the commercialization partner for the snake robot.
“We build robots — more than just snakes, we have legged robots, robot arms,” Choset says. “In fact, some people have used our robot modules to build a self-driving car kit. And it just goes on.”
The company is a way for Choset to keep working with some of his most talented students.
“As a professor, we have these amazing people come through … and then they graduate and I lose them,” says Choset. “So my selfish secret agenda was to start a company with the sole purpose to keep them near me, [keep] them in Pittsburgh — and I’ve got to tell you, it’s paid off.”