Quadruped robots may outperform wheeled robots at traversing rough terrain, but they are unable to maintain balance when moving along narrow ridges. That could change, however, as scientists devised a way to make it possible to walk along the balance beam.
Led by Ast. Professor Zachary Manchester, an engineer at Carnegie Mellon University’s Robotics Institute and his team, started with a commercially available Unitree A1 robot. They attached two of his devices, called reaction wheel actuators, to the bot’s back. Called RWA for short, these tools are commonly used to adjust the angular momentum of satellites.
“Basically there is a big flywheel with a motor attached to it,” Manchester said. “If you turn the heavy flywheel in one direction, the satellite will rotate in the opposite direction. You attach it to the body of the quadrupedal robot.”
One of the RWAs controls the pitch axis of the bot, the other the roll axis. Both single he is housed in a 4.3 kg (9.5 lb) module. RWA simply (and automatically) compensates for changes in the center of balance, so it doesn’t matter which leg of the robot is in contact with the beam.
Carnegie Mellon University
In lab tests, the robot was able to walk about 3 meters (9.8 feet) on a 6 cm (2.4 inch) wide wooden beam and survived an attempt to kick it over. When dropped upside down from a height of about half a meter, it flipped in the air and could even land on its feet like a cat.
Manchester believes additional features like this will help bring quadrupedal robots out of the lab and into real-world use.
“Quadrupeds are the next big thing after robots,” he said. “I expect to see more of them in the wild in the next few years.”
The team plans to present a paper on their research at the 2023 International Robotics and Automation Conference in London this June. You can see the modified Unitree A1 balance beam walking behavior in the following video.
balance beam walking robot
Source: Carnegie Mellon University
