Robots: Should they walk on two legs or move on wheels?

Should Robots Walk on Two Legs?

Should Robots Walk on Two Legs?

Future Tense
The Citizen's Guide to the Future
Nov. 14 2011 1:53 PM

Should Robots Walk on Two Legs?

CHARLI-2, the Cognitive Humanoid Autonomous Robot with Learning Intelligence, Version 2
CHARLI-2, the Cognitive Humanoid Autonomous Robot with Learning Intelligence, Version 2

Courtesy Virginia Tech.

Roboticist Dennis Hong envisions a world in which automatons—like in The Jetsons—help us out around the home. He admits that this won’t happen any time soon; for instance, robot makers face a hard path to teach their machines how to do something as simple as fold a towel.

Torie Bosch Torie Bosch

Torie Bosch is the editor of Future Tense, a project of Slate, New America, and Arizona State that looks at the implications of new technologies. 

They also need to settle a hot debate within the robotics world: Should robots be bipedal like humans or use treads, wheels, or some other method to get around? Hong is a proponent of the humanoid model, as you can see from his work with the RoboCup, a soccer competition for robots. (RoboCup’s goal is to have the automaton winners play the victors of the human World Cup, and have a competitive game, by 2050. Hong admits it’s an ambitious target.)


The reason robots should be bipedal, he argues, is that our environment is already built for humans. Stairs aren’t navigable by wheels or treads, for one thing. By some estimates, 80 percent of land mass isn’t accessible by wheels: “Legs are king.”

The anti-bipedal corner contends that royal though they may be, legs are just too difficult—and too expensive—to craft. But Hong believes that the challenge and cost are worthwhile because of the fringe benefits to creating bipedal robots: “In the effort of trying to make a bipedal robot walk, we get to understand how we humans walk,” he says. This knowledge could be crucial to creating better prosthetic legs and could have other medical applications as well.

At Ciudad de las Ideas (City of Ideas) in Puebla, Mexico, on Thursday, Hong made his case for humanoid robots. Technical specs aside, the strongest support for his argument may have come from his young son. Watch him play with one of Hong’s soccer-playing robots below—and try to imagine a kid reacting that way to a wheeled robot without soccer-ball-kicking skills.

The video also demonstrates how far robots have to go: When Ethan runs to get a big blue ball—presumably, he thinks it will be more fun for the robot—his father tells him that he has to use the orange one instead. Darwin, the robot, can only recognize the little orange one.

Future Tense is a partnership of SlateNew America, and Arizona State University.