By Lev Grossman (Time, 8 Jun 2015)
If it takes so much backbreaking math, why teach a robot to walk? Why bother?
Predator drones don’t walk. Roombas don’t walk. R2-D2 doesn’t walk. The attachment to legs and really the human form at all seems really old-fashioned, even atavistic. The surface of the earth is a challenging enough environment for a robot as it is. Why not just put wheels on a robot and call it a day?
This is not an uncontroversial topic in the world of robotics. The conventional argument in favor of humanoid robots is that they’re better at operating in environments that were built by and for humans. According to Gill Pratt, who coordinates robotic challenges for DARPA:
Doorways have a certain width, door handles have a certain height, the steering wheel on cars is in a certain place. All of these things are built for our form. If you want a machine to adapt to it, that makes a lot of sense.
But there’s room for disagreement on this score. Colin Angle is one of the world’s foremost roboticists and the CEO of iRobot, a prominent supplier of robots to the military; it also makes the Roomba. One thing iRobot doesn’t make is humanoid robots. “Walking robots aren’t particularly practical,” Angle says. He prefers wheels or even tank-style tracks–as examples he gives iRobot’s Kobra and PackBot robots, which are marketed to military and civil defense agencies.
They can run up stairs at 5 to 10 mph. They don’t have to step, and you can drop them off the second story of buildings and they’ll survive. They’re designed to operate in human-style spaces, but they’re radically simpler solutions than legs.
He supports competitions like the [DARPA’s recent] Robotic Challenge as a way to stimulate innovation, but he points out that when the Fukushima disaster happened, there were in fact rescue robots already available. They just didn’t look like people.
When push came to shove a few years back, when the world needed a robot to go inside a reactor and help figure out how to shut it down, the robot that went in had tracks.
There are good arguments on both sides. Jerry Pratt, a lead engineer at the Florida Institute for Human and Machine Cognition, is eloquent on the topic of the human body’s exceptional mobility and its ultimate superiority to other forms in dealing with rough terrain.
Humans and primates are just so good at getting places. You can crawl under a table, get on top of the table, move the table, you can climb over a garbage can, you can squeeze between objects. Imagine a door that’s wedged so it can only open about 10 inches: a human can get through that, no problem. The dimension of a human are just really well suited for mobility through a really challenging environment.
Though if there’s one thing everyone agrees on, it’s that walking robots aren’t anywhere near ready for the field yet.