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1993-05-03
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PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
FOR IMMEDIATE RELEASE
Scientists and engineers at NASA's Jet Propulsion
Laboratory have begun an extensive period of field testing a
semi-autonomous navigation system on a computer-operated vehicle
that may be used in future planetary explorations.
The first, continuous semi-autonomous navigation (SAN)
traverse, in rough natural terrain, was achieved May 7, 1990.
Brian Wilcox, supervisor of the Robotic Sensing and
Perception Group, said the summer-long testing program would be
carried out mostly in the Pasadena Arroyo, a dry river bed,
adjacent to JPL.
The program is part of NASA's new exploration technology
initiative which is to develop technologies for the Space
Exploration Initiative (SEI) announced by President Bush last
July.
Developing new technologies, including a new generation of
planetary rovers, is seen as critical to the success and cost
effectiveness of the SEI. The Planetary Rover project will
develop systems to enable the manned and unmanned vehicles needed
for surface transportation.
Surface transportation systems required by the SEI include
unmanned rovers for outpost site survey and for regional robotic
exploration and science; piloted rovers for transportation bothlocal and long range, and unmanned cargo handling, construction
and mining.
Increased traverse distance, longer life and autonomous
operations are required for the unmanned roving vehicles for the
program. Traverse distances of up to several kilometers per Earth
day and a mission life from one to five years is desired for the
next generation of robotic exploring vehicles.
The operation of an autonomous unmanned rover, whether on
the surface of Mars with round-trip light time of between eight
and 40 minutes, or any other situation resulting in minutes of
time delay, involves an entirely unproven technology.
Two advanced forms of unmanned rover navigation are under
development at JPL. They are computer aided remote driving (CARD)
and semi-autonomous navigation (SAN).
The CARD technique allows a human operator to remotely
drive a vehicle by planning and designating an extended (10s of
meters) obstacle-free path with a three dimensional display of
images from stereo cameras aboard the vehicle. The path is then
transmitted to the vehicle for autonomous execution.
The SAN technique allows a human operator to determine a
nominal extended route (10s of kilometers) for the vehicle, with
a specific path taken by the vehicle around local obstacles
determined automatically from the rover's sensor data and stored
data base.
The navigation testbed is a six-wheeled, three-body,
articulated vehicle the experimenters call "Robby." It's about 13
feet long, five-feet wide, and more than 6.5-feet high. Its 35-
inch diameter wheels and articulated body permit it to go over
obstacles a meter high.
The 2,500-pound vehicle contains two computer systems, one
for perception and planning and one for control of the actuators
in the wheel drive and arm control. The robotic arm has six links
and six degrees of freedom with an additional pivot axis and
gripper providing two more degrees of freedom.
There are four cameras on the pan-tilt head capable of
stereo correlation to provide three-dimensional images of
objects. A motor generator provides 3,500 watts of power and
batteries provide 24 volts.
Other parts of the rover program include the development of
advanced mission operation, mobility and power technology at
JPL; the development of an innovative "legged" vehicle concept,
as opposed to using wheels, at Carnegie Mellon University in
Pittsburgh, Pa.; mission operations research at the Ames Research
Center at Moffett Field, Calif., and piloted rover technology at
the Marshall Space Flight Center at Huntsville, Ala.
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#1305
4/19/90jjd