Virginia Tech's Humanoid Robot CHARLI Walks Tall

The robot can walk and gesture using an ingenious linkage system of pulleys and springs

2 min read
Virginia Tech's Humanoid Robot CHARLI Walks Tall

romela charli

Dennis Hong, a professor of mechanical engineering and director of Virginia Tech's Robotics & Mechanisms Laboratory, or RoMeLa, has created robots with the most unusual shapes and sizes -- from strange multi-legged robots to amoeba-like robots with no legs at all.

Now he's unveiling a new robot with a more conventional shape: a full-sized humanoid robot called CHARLI, or Cognitive Humanoid Autonomous Robot with Learning Intelligence.

The robot is 5-foot tall (1.52 meter), untethered and autonomous, capable of walking and gesturing.

But its biggest innovation is that it does not use rotational joints.

Most humanoid robots -- Asimo, Hubo, Mahru -- use DC motors to rotate various joints (typically at the waist, hips, knees, and ankles). The approach makes sense and, in fact, today's humanoids can walk, run, and climb stairs. However, this approach doesn't correspond to how our own bodies work, with our muscles contracting and relaxing to rotate our various joints.

Dr. Hong and his students wanted a system based on the human anatomy -- and that they could build in short time and on a small budget. So to generate movement, they engineered an ingenious linkage system of pulleys and springs. This actuation system is much lighter than those of other humanoids, and the team was able to design and built it in 1.5 years with only about US $20,000 and donated software/hardware like LabVIEW and SingleBoard RIO.

Dr. Hong is already working on a new version of the robot, CHARLIE-H, that will use linear actuators to power the new legs. You can see the actuator, the black cylinder, on the photo below:

Linear actuators have been tried in humanoids before but, as far as I know, without much success. So I look forward to seeing how the approach will work out in this case. Will CHARLI be able to walk more naturally than Asimo? Only time will tell.

Dr. Hong, for his part, remains confident he'll be able to improve the overall capabilities of humanoid robots in particular bipedal locomotion.

Or as he put it as CHARLI took its first steps, "One small step for a robot, one giant leap for robotics."

Watch the robot (the current version is called CHARLIE-L) in action:

More photos:

Photos and video: RoMeLa and Virginia Tech

UPDATE: Corrected details about the use of linear actuators, which will be present in an upcoming version of the robot.

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