Remember Dr. Guero, the robot builder that stunned everyone last year with his bicycle riding Primer-V2 humanoid robot? He's back with another astonishing robot feat. This time his Primer-V4 robot is a full fledged tightrope walker!
Pretty darn amazing, especially considering that just a few short years ago many of the hobby level humanoid robot builders were lucky to keep their robots balanced and upright while walking for an extended period or boxing in the ROBO-ONE ring.
The tightrope used for this feat was a 4mm diameter cable suspended 1 meter above the floor. The technical challenges were significant and considerably different from normal humanoid robot walking. When a bipedal robot walks on the ground the standard approach is to apply gyro sensor feedback corrections primarily to the leg servos to shift the center of gravity. The arms don't play a significant role.
With tightrope walking the arms and upper body play a much more critical role in shifting the robots center of gravity to keep it balanced and avoid crashing to the floor. Dr. Guero's blog doesn't mention the use of any safety net, but I'm sure he had to catch the robot quite a few times before he got it working perfectly.
The robot's feet have a small slot for the tightrope, which is fair enough. A human tightrope walker in the circus would cup their feet and use their toes in the same fashion.
Here's Dr. Guero's bicycling robot, for those that haven't already enjoyed it: