Air-powered leopard robot doesn’t need a complex brain to walk:
ost of the quadruped robots
that have previously wowed and terrified us on video have relied on
powerful computational engines and substantial processing power to move
their mechanized limbs. This approach has provided some incredibly
lifelike, efficient movements in robots like
Boston Dynamics’ WildCat,
but their complicated nature has slowed the deployment of walking
robots outside of the lab. A team from Osaka University in Japan is
working on a more natural approach to walking robots that sacrifices
power in the name of simplicity.
The robot is called Pneupard, a
regrettable contraction of “leopard” and “pneumatic.” Knowing that, you
should have a basic idea of what makes this system of locomotion
different. Rather than using actuators and motors to move, Pneupard has a
series of artificial muscles that run on compressed air. Each muscle is
made from a rubber tube sheathed in nylon and contracts as air is
pumped in. The air-powered limbs of a so-called “biometric”
robot
have the potential to be more realistic than one based on electric
motors. They actually deform and flex without breaking, which allows for
a wider range of movement.
This design is much more
analogous to a real muscle, so the researchers believe it will be easier
to create lifelike locomotion of the sort seen in WildCat. Basically,
the Osaka University team wants to see how locomotion can be offloaded
from a centralized robotic brain to the rest of the body. Their approach
takes into account the way a real animal works — it’s not all higher
brain functions controlling your gait and posture. The feedback of
peripheral nerves, the brainstem, spine, and muscles all figure into the
way we move.
Pneupard
doesn’t even have a complex brain right now — in the video above it is
relying entirely on a type of rhythmic controller called a central
pattern generator, or CPG. That means there are no external signals
telling the limbs how to move, instead everything is based on the
interaction of the pneumatic muscles and skeletal frame, which
rhythmically cycle back to their starting positions after each step. A
CPG like this is essentially a biological system, so it
could make future robots more lifelike.
The
current design is intentionally simple (and loud). The clicking sound
in the video is from the on-board valves flicking on and off to control
airflow, but it was even louder before researchers cut down the number
of muscles. With fewer muscles, the team is able to
study its CPG system
and improve future versions. They have already installed force sensors
on the robot’s feet which should be able to give Pneupard a more natural
gait. More muscles could be re-added later to smooth out the motion.
Just because Pneupard doesn’t have a brain right
now doesn’t mean it never will. Integrating a CPG with the more traditional pre-programmed movements of robots like
BigDog and WildCat could be the thing that makes walking robots easier and cheaper to develop in the future.
