Saving Space and Time: The Tractor
That Einstein Built
Environmental and Agricultural Resources
Originating Technology/NASA Contribution
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In
this photo, the Gravity Probe B (GP-B) space vehicle
is being assembled. The GP-B progam is among the
most thoroughly researched programs ever undertaken
by NASA. |
In 1984, NASA initiated the Gravity
Probe B (GP-B) program
to test two unverified predictions of Albert Einstein’s
theory of general relativity—hypotheses about the ways
space, time, light, and gravity relate to each other. To
test these predictions, the Space Agency and researchers
at Stanford University developed an experiment that would
check, with extreme precision, tiny changes in the spin
direction of four gyroscopes contained in an Earth satellite
orbiting at a 400-mile altitude directly over the Earth’s
poles.
When the program first began, the researchers assessed
using Global Positioning System (GPS) technology to control
the attitude of the GP-B spacecraft accurately. At that
time, the best GPS receivers could only provide accuracy
to nearly 1 meter, but the GP-B spacecraft required a system
100 times more accurate.
To address this concern, researchers at Stanford designed
high-performance, attitude-determining hardware that used
GPS signals, perfecting a high-precision form of GPS called
Carrier-Phase Differential GPS that could provide continuous
real-time position, velocity, time, and attitude sensor
information for all axes of
a vehicle.
The researchers came to the realization that controlling
the GP-B spacecraft with this new system was essentially
no different than controlling an airplane. Their thinking
took a new direction: If this technology proved successful,
the airlines and the Federal Aviation Administration (FAA)
were ready commercial markets. They set out to test the
new technology, the “Integrity Beacon Landing System,”
using it to automatically land a commercial Boeing 737
over 100 times successfully through Real-Time Kinematic
(RTK) GPS technology.
The thinking of the researchers shifted again—from automatically
landing aircraft, to automating precision farming and construction
equipment.
Partnership
The Stanford/NASA precision aircraft landing system had
such clear-cut commercial applications that a group of
the Stanford researchers in Menlo Park, California, created
their own company, Novariant
Corporation (originally called
IntegriNautics Corporation), and submitted a proposal to
NASA’s Small
Business Technology Transfer (STTR) program
at Langley
Research Center.
In 1994, the company was awarded the STTR contract. In
partnership with NASA, the FAA, and Stanford, the firm
planned to research and develop a “highly reliable navigations
system for precision approach and landing, using navigation
signals transmitted by satellites and similar signals transmitted
by low-cost ‘Integrity Beacons’ on the ground.”
The STTR contract had also identified other potential applications,
including commercial ones for automated agricultural and
construction equipment. In 1996, Novariant spawned a subsidiary,
AutoFarm, to focus on agricultural applications of its
GPS auto-steering technology, and a tractor-steering technology
was trademarked with the name, RTK (Real-Time Kinematic)
AutoSteer. RTK AutoSteer was released in 1999 to farmers
in California, Arizona, and Australia.
Product Outcome
For traditional farming, when using human-steered tractors,
it is nearly impossible to create repeatable straight rows.
Tractors shift and wobble, and farmers and operators make
natural digressions from the exact rows they try to cultivate.
Despite these dilemmas, farmers know the advantages of
accurately planting seeds, distributing fertilizers, and
watering. Seeds planted directly in the centers of rows,
then sprayed accurately with fertilizer and water, will
yield increased crops, reduced chemical use, and less wasted
water. It is, therefore, to the benefit of the farmer to
be as precise as possible.
RTK AutoSteer technology mounts to most standard farm equipment
set-ups and delivers accurate steering of tractors to within
1 inch. It is ideal for the preparation of fields, the
laying of beds, planting, cultivating, and tilling.
It eliminates skipped rows or unnecessary overlaps by creating
perfect rows with repeatable accuracy. In addition, it
can run any time of day or night, and even on weekends—in
dust, fog, wind, and extreme heat.
The device has the capability to change the face of farming
forever by speeding field operations and maximizing productivity,
which reduces operating costs as well as capital equipment
expenditure.
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RTK
AutoSteer helps farmers reduce fuel costs, decrease
driver fatigue, and eliminate overlap. Pictured
here are GPS system antennas roof-mounted on a
farming tractor and the touchscreen controls for
the GPS guidance system installed in the cockpit. |
The AutoSteer system uses a steering wheel-mounted control,
multiple GPS antennas on the tractor cab roof, and an RTK
base station antenna/transmitter. The GPS antennas in the
roof module directly measure position (latitude, longitude,
and altitude) plus orientation (roll, pitch, and yaw) of
the tractor for steering corrections. The base station
allows GPS signals to be improved to consistently repeatable
sub-inch accuracy.
The multiple-GPS roof module allows vehicle steering to
be corrected before a guess row error or overlap is created.
The roof module is all-weather rated, which means it is
both water- and dust-proof, a definite plus for equipment
that will be exposed to the elements.
The intuitive AutoSteer touchscreen display is simple to
operate, similar to using an ATM, and is designed with
a transreflective screen for ease of readability in the
sunshine. Additionally, a quick-connect design makes it
easy to move between vehicles, which helps it seamlessly
integrate across fleets of mixed makes and models. Easy-access
connectors and quick-release latches make it simple to
transfer the AutoSteer system between tractors, floaters,
and sprayers, and it connects in minutes without tools.
Unlike the one-size-fits-all approach of other GPS steering
systems, the AutoSteer system adjusts for changes in the
vehicle’s performance profile as a result of changes in
implements and cargo, terrain, or even through normal wear
over time. The system has tuning and calibration “wizards”
that enable tuning it to the operating characteristics
of a specific vehicle, and it adjusts as the machine’s
performance changes. It is even accurate over uneven terrain.
The system can directly measure the roll of the vehicle
frame as it passes over such terrain. The multiple antennas
calculate and compensate for vehicle tilt, whereas a single
antenna system will mistakenly assume the vehicle has shifted
over.
The technology is now found on farms across the world,
and in April 2006, Novariant was inducted by the Space
Foundation into the prestigious Space Technology Hall of
Fame.
AutoFarm® is a registered trademark of Novariant Corporation.
RTK AutoSteer™ is a trademark of Novariant Corporation.
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