Famed "snakebot" can now swim

One of the most awarded robots in history has a new trick in its slithery arsenal.
Written by Greg Nichols, Contributing Writer on

A robot that's developed something of a mythology over the years now has a new trick. Snakebot, named ground rescue robot of the year in 2017 and helping its creator win the "Oscars of automation" in 2019, can now swim. 

The robot consists of several actuated joints that work together to produce a range of motions. Snakebot can stand slither, roll, stand up to pull itself over obstacles, and climb a variety of objects and surfaces. CMU robotics professor Howie Choset and systems scientist Matt Travers are the brains behind Snakebot. Their creation can propel itself into confined spaces that dogs and people cannot reach.

"We can go places that other robots cannot," Howie Choset, the Kavčić-Moura Professor of Computer Science, told CMU's Aaron Aupperlee. "It can snake around and squeeze into hard-to-reach underwater spaces."

Snakebot helped search through the rubble for survivors after a major Mexico City earthquake. Travers led a team to Mexico City in 2017 to use robot snakes in a search-and-rescue mission after the earthquake.

Swimming is a new trick, and it adds impressive utility to a simple yet surprisingly capable modular design. The team from the Biorobotics Lab in the School of Computer Science's Robotics Institute tested the new Hardened Underwater Modular Robot Snake (HUMRS) in a university pool recently, directing the robot through an underwater obstacle course of hoops.

The robot may have defense applications. It was developed under a grant from the Advanced Robotics for Manufacturing (ARM) Institute to help the Navy inspect ships, submarines, and underwater infrastructure for damage or as part of routine maintenance. Currently that's done by divers or delayed until ships can reach a dry dock, both of which involve substantial infrastructure, time, and expenses.

But a robotic snake that can squeeze into tight spaces can do much of the inspection remotely.

"If they can get that information before the ship comes into a home port or a dry dock, that saves weeks or months of time in a maintenance schedule," said Matt Fischer, the program manager at the ARM Institute working on the project, who served in the Navy for three years. "And in turn, that saves money."

Interestingly, Fischer was once tasked with crawling into the ballast tanks of a submarine during his service, lending a personal triumph to helping equip a robot for the task.

Of course, military technology often transfers to commercial applications. Infrastructure inspection has been a major area of development and deployment for robots, which have found ready adopters among customers like the oil and gas industry and utilities.

Outside the military, the robots could inspect underwater pipes for damage or blockages, assess offshore oil rigs, or check the integrity of a tank while it is filled with liquid. The robot could be used to inspect and maintain any fluid-filled systems, said Nate Shoemaker-Trejo, a mechanical and mechatronics engineer in the Biorobotics Lab working on the submersible snakebot.

"I'm surprised that we made this robot work as fast as we did," Choset said. "The secret is the modularity and the people working on this technology at CMU."

Choset won the 2019 Engelberger Robotics Awards, the world's most prestigious robotics honor. At CMU, he's led teams developing modular segmented robots, including a snake robot used in disaster relief.

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