Human-like robot takes its first steps, drives Segway at
Johnson Space Center
Human-like hands, fingers and even television camera eyes have
been hallmarks of NASA's Robonaut, but recent work seeks to give
the nimble robot legs, or at least a leg, and even wheels.
Robonaut took its first steps recently during tests at the
Johnson Space Center in Houston, using a single "space leg" to move
around the outside of a simulated Space Station. Other recent tests
put the humanoid robot on wheels, a Segway scooter to be exact, and
let it take to the road.
In either configuration, Robonaut's head, torso, mechanical arms
and hands maintain their ability to use the same space tools as
humans. In the tests using its "space leg," Robonaut commuted like
a futuristic construction worker hand-over-hand outside a mock
spacecraft. Aboard the gryo-stabilized wheels, it glided from one
test station to another as its descendants might someday on the
surface of the Moon or Mars.
Tests with the leg confirmed that Robonaut could climb around
the outside of a spacecraft using handholds and plant its foot at a
work site to make repairs or install parts. NASA's goal is to build
robots that could "live" on the outside of spacecraft, ready for
routine maintenance or emergencies. Humans inside the spacecraft
would operate Robonaut with wireless controls.
The wheeled tests provided initial proof of concept for
planetary Centaurs that merge humanoid robots with rovers. Those
tests put Robonaut through its paces while mounted on a Segway
Robotic Mobility Platform. They showed that a single teleoperator
could simultaneously control both the robot's mobility and
dexterity with a wireless control system.
The climbing tests were a significant step in Robonaut's
development, proving the system's capability for climbing,
stabilizing and handling extravehicular activity (EVA) tools and
interfaces in the space environment. The test featured a
battery-powered, wireless Robonaut system mounted to an air-bearing
sled, floating on a cushion of air, to eliminate friction and
emulate the sensations experienced by astronauts working in zero
gravity. Robonaut climbed using EVA handrails and plugged its
stabilizing "space leg" into a standard space station WIF (Worksite
Interface Fixture) socket, while its operators drove Robonaut's
multiple limbs using innovative new telepresence controls.
"This test proved Robonaut can be operated wirelessly using an
interchangeable base for different stabilization and locomotion
systems -- and it did it in a frictionless, space-like
environment," said Test Conductor Dr. Robert Ambrose of JSC's
Automation, Robotics and Simulation Division. "These are all key
capabilities needed for the development of future 'EVA squads' that
leverage the combined talents of humans and robots to make vast
improvements in spacewalk productivity."
The Robonaut Project, which Ambrose leads, is a collaborative
effort with the Defense Advanced Research Projects Agency (DARPA),
and has been under development at JSC for several years. There are
two Robonauts, each with highly dexterous hands that can work with
the same tools humans use. Operators remotely control movements of
the Robonauts' heads, limbs, hands and twin cameras through a
combination of virtual-reality interfaces and verbal commands,
relayed either through dedicated cabling or wireless systems.
In order to move about in a zero-gravity environment, a robot
must be able to climb by itself, using gaits that smoothly manage
its momentum and that minimize contact forces while providing for
safety in the event of an emergency. To access worksites aboard the
International Space Station and future spacecraft, robots must
interact with spacewalking aids designed for humans including
tethers, handrails and work anchors.
"The tests were very successful," Ambrose said. "The Robonaut
team learned which climbing maneuvers are more feasible than
others, and tested automated software safety reactions using the
robot's built-in force sensors. We also identified new
opportunities for using these sensors in semi-automatic modes that
will help operators across short (1-10 second) time delays.
Our team will continue to tackle these challenges as NASA looks
forward to applying human-robotic interaction to the tasks
associated with returning to the Moon and going on to Mars."