Walking Robots posted by Ben

Walking Robot photo

There's suddenly quite a bit of buzz around the net this morning about energy-efficient walking robots. The main complaint from folks is that they haven't seen video of these bad boys of perambulation in action.

Which is funny, because this is hardly a new field. Video from a number of university research labs has been out for years, and I've actually seen these this type of robot in action, in person.

The concept is so simple that it's brilliant. Unlike the Honda Asimo robot, which uses almost ten times the relative energy of a human (and some pretty complex inner workings), these mimic human movement by using simple mechanics and gravity. The earlier models essentially fall forward, much like we do, but keep themselves from hitting the ground by extending a leg, which starts the whole falling forward motion all over again, just in time for the other leg to swing forward and continue the process.

The models that I've seen worked primarily because they were placed on a declining plane, in effect giving them an extra assist from gravity. Now what's cool about the bot described in this Wired article is that it combines those earlier, purely mechanical systems with software that learns from its mistakes.

A robot designed by Russ Tedrake of Massachusetts Institute of Technology is equipped with sensors that help the machine learn to walk in a way similar to humans' gait. Appropriately, the machine is called "Toddler."

The robot's sensors measure the machine's motion, tilt and rate of movement and then direct small motors to adjust and compensate for changes.

"It can learn to walk in 20 minutes," Tedrake said. "Once it learns to walk, then it adapts its gait to new terrain."

Similar approaches in building evolutionary algorithms have led to breakthroughs in task-oriented industrial design, like computer systems that begin with a set of basic parameters for, say, any kind of movement, then build thousands of random models and "mating" the most effective through a series of generations until it has something that works, often in really bizarre ways. This system is somewhat different, in that the initial operational parameters are defined by a set physical structure, which means that you're not going to see an onboard computer system redesigning a leg, for instance.

While information on these new walking robots is still fairly scarce, I look forward to being able to read more detailed accounts of how the team that built this settled on the physical design and integrated its computer analysis and control system into that design.