Agile Robots

Computer scientists have created
machines that have the balance
and agility to walk and run across
rough and uneven terrain, making
them far more useful in navigating
human environments.
W alking is an extraordinary feat of biomechanical engineering.
Every step requires balance and the ability to adapt to
instability in a split second. It requires quickly adjusting where
your foot will land and calculating how much force to apply to
change direction suddenly. No wonder, then, that until now robots
have not been very good at it.
Meet Atlas, a humanoid robot created by Boston Dynamics, a
company that Google acquired in December 2013. It can walk
across rough terrain and even run on flat ground. Although
previous robots such as Honda’s ASIMO and Sony’s diminutive
QRIO are able to walk, they cannot quickly adjust their balance; as
a result, they are often awkward, and limited in practical value.
Atlas, which has an exceptional sense of balance and can stabilize
itself with ease, demonstrates the abilities that robots will need to
move around human environments safely and easily.
Robots that walk properly could eventually find far greater use in
emergency rescue operations. They could also play a role in
routine jobs such as helping elderly or physically disabled people
with chores and daily tasks in the home.
Marc Raibert, cofounder of Boston Dynamics, pioneered machines
with “dynamic balance”—the use of continual motion to stay
upright—in the early 1980s. As a professor at Carnegie Mellon
University, he built a one-legged robot that leaped around his lab
like a pogo stick possessed, calculating with each jump how to
reposition its leg and its body, and how aggressively to push itself
off the ground with its next bound. Atlas demonstrates dynamic
balance as well, using high-powered hydraulics to move its body
in a way that keeps it steady. The robot can walk across an
unsteady pile of debris, walk briskly on a treadmill, and stay
balanced on one leg when whacked with a 20-pound wrecking
ball. Just as you instinctively catch yourself when pushed, shifting
your weight and repositioning your legs to keep from falling over,
Atlas can sense its own instability and respond quickly enough to
right itself. The possibilities opened up by its humanlike mobility
surely impressed Google. Though it’s not clear why the company
is acquiring robotics businesses, it bought seven others last year,
including ones specializing in vision and manipulation.
Atlas isn’t ready to take on home or office chores: its powerful
diesel engine is external and noisy, and its titanium limbs thrash
around dangerously. But the robot could perform repair work in
environments too dangerous for emergency workers to enter, such
as the control room of a nuclear power plant on the brink of a
meltdown. “If your goals are to make something that’s the
equivalent of a person, we have a ways to go,” Raibert says. But
as it gets up and running, Atlas won’t be a bad example to chase
after.
— Will Knight