New Robot Technology Indicates Bright Future for Prosthetics 
From: Rehab Management Magazine - 04/2005 - page 10

At the recent annual meeting of the American Association for the Advancement
of Science (AAAS), three independent research teams unveiled novel,
low-energy, bipedal robot models, which displayed human-like gait when
walking. The latest advancements in the development of these robots may offer
promise for amputees hoping to one day use prosthetics that feel more like a
natural limb.  

Read the entire story at:
http://www.rehabpub.com/departments/42005/2.asp

Image caption:
Left to right, Delta, MIT, and Cornell walking robots.

Links:
Walking robots
http://www-personal.engin.umich.edu/~shc/robots.html

Robots toddle along with human efficiency
http://www.nature.com/news/2005/050214/pf/050214-13_pf.html

New Robots Based on Old-Style Toys
http://dsc.discovery.com/news/briefs/20050214/robot.html

'Toddler' Takes a Robotic Step Forward
http://www.npr.org/templates/story/story.php?storyId=4511843

New Robots Approach More Humanlike Gaits
http://www.sciam.com/article.cfm?articleID=0005CC27-34A1-1215-B4A183414B7F0000&chanID=sa009

Robo-Toddler Learns to Walk Like a Human
http://apnews.myway.com/article/20050218/D88AUDP80.html

One giant leap for walking robots
http://msnbc.msn.com/id/6975006

Humanoid robots walk naturally
http://www.trnmag.com/Stories/2005/022305/Humanoid_robots_walk_naturally_022305.html

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Rambling Robots Show Human Efficiency
From: New Scientist - 02/17/2005
By: Will Knight

Three robots that stride like human beings made their debut at the annual
meeting of the American Association for the Advancement of Science on Feb.
17. The machines, which were produced by researchers at the University of
Michigan, MIT, Cornell University, and Delft University in the Netherlands,
amble along using simple mechanical dynamics and minimal motorization; each
robot's frame and joints are configured so that they can walk without
overexerting themselves. "Our robots demonstrate that utilizing the natural
dynamics of the body can make robots much more efficient," said the
University of Michigan's Steve Collins. The robots' designs were inspired by
mechanical walking toys that automatically respond to gravity by striding
down a slope, and this capability was refined to accommodate flat surfaces
with the addition of a few motors. The Cornell and Delft robots boast
exceptional power efficiency, consuming around the same amount of energy as
the average walking human--about 10 times less than is consumed by Honda's
Asimo android. The MIT bot, nicknamed "Toddler," was hailed by one robotics
researcher as the most conceptually innovative of the three because it adapts
to terrain via a learning algorithm. University of Michigan researcher Art
Kuo noted that practical walking bots must be made capable of climbing stairs
through a combination of simple dynamics and greater control. 

http://www.newscientist.com/article.ns?id=dn7023

---

US scientists build robot that learns to walk like toddler
From: Science - 02/19/2005

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 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. By 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 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 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. 


Links:
http://www.sciencemag.org
