[extropy-chat] walk this way

[spike]

This is so wicked cool:

http://www.cnn.com/2005/TECH/02/17/robot.toddlers.ap/index.html

They are actually reporting two breakthroughs here, which
causes me to suspect either the press has goofed the story
or that something else is wrong with it.  They are reporting
that they have discovered a far more efficient way for
robots to walk using springs (which is believable and 
exciting) and that the device itself learns (which is
exciting as hell, but dubious).

spike




Robot 'learns' to walk like a toddler
Thursday, February 17, 2005 Posted: 5:12 PM EST (2212 GMT) 
 
The walking robot Cornell moves like a human, falling and catching itself as
it moves forward. 
      

WASHINGTON (AP) -- The difference between man and machine is shrinking.
Scientists have developed a robot that "learns" to walk like a toddler,
improving its step and balance with every stride.

The walking robot looks more like a moving Erector set than a human being,
but the machine has the unmistakable gait of a person strolling along. The
robot uses its curved feet and motorized ankles to spring its legs forward,
its arms swinging at every step to help with balance.

Researchers on Thursday showed off the learning, walking robot, along with
two less-advanced models, at the national meeting of the American
Association for the Advancement of Science. A report on the research appears
this week in the journal Science.

The machines use what the researchers called a "passive-dynamic design" that
closely mimics the way humans walk. Earlier robots required powerful
machines to stroll, with each leg, knee and ankle requiring motorized
assistance. The effort requires a lot of energy.

The passive dynamic design uses gravity, along with muscle-like springs and
motors. The energy required is just a fraction of that needed by other
walking robots, said Andy Ruina, a Cornell University researcher.

Ruina said the walking robots move like humans, falling and catching
themselves as they move forward. This essentially is the same movement
people use, a motion toddlers must master to walk.

"We let the machines take care of a lot of the motion," he said. In
contrast, most walking robots, such as Asimo, developed by the Honda Motor
Co., require a motor to power every motion.

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."

He said the sensors take measurements at the rate of 200 times a second and
constantly send new instructions to the motors that control the tilt and
motion. The sensors also direct actuators that control the tension on
springs in the robot ankles. This helps the machine push forward with each
stride.

"Every time it takes a step, it changes the parameters a little bit, based
on its experience," Tedrake said. "It will walk on any surface and adjust
the way it walks."

In effect, the robot changes its stride just as humans do when moving from
sand to grass to pavement.

He said the machine even has learned to walk on a treadmill, making
adjustments as the surface tilts or speeds up. The robot can start on its
own and even walk backward.

The big advantage of the passive-dynamic robots is that they require about
the same energy that humans use to walk. This is only one-tenth of the
energy needed to make Asimo go, Ruina said.

The less energy used, the longer that the robots can operate without needing
new batteries.

"For a robot to ever be practical, it will have to be able to run for a long
time," Ruina said.