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Representatives of manufacturers
of construction equipment differ considerably on the subject of
machine control and guidance. In recent months, some people have
said that the future will see machine control taken away from operators
because they are less efficient and, in the long run, more expensive
than the machines themselves. Reports indicate that the cost of
labor is increasing more quickly, in proportion, than the cost of
machines. Responses were forthright and honest, with many manufacturers
of machines quick to point out that control options are often add-on
products from other manufacturers, usually instrument makers.
Joint ventures and agreements
between manufacturers of such machines as graders and loaders and
makers of instrumentation (often with laser receiver
and global positioning system as part of product terminology)
seem likely to increase in the next few years. Two leaders in their
respective fields–Caterpillar Inc. and Trimble–reached
agreement earlier this year to form a joint venture called Caterpillar
Trimble Control Technologies LLC; each company owns 50%. "The
two companies have worked together for six years on a variety of
machine control technology initiatives," notes Lea Ann McNabb
for Trimble. "The initial distribution is interesting. The
joint venture will supply products to both Caterpillar and Trimble,
and each partner will distribute, service, and support the products
using their company's independent distribution channels."
Is There a Need for
Additional Machine Guidance?
Should you feel you are
being left behind in these technologies? How big is the market for
machine guidance and control? How much growth has been seen so far?
"Over the past five years, there have been more than 300,000
machines sold in the United States alone that can potentially benefit
from the use of this technology," asserts Karl Ramstrom, senior
vice president and general manager of Trimble's Engineering and
Construction Division. "The combined strengths of Trimble and
Caterpillar in this venture will enable us to reach a larger part
of this customer base and accelerate the growth and acceptance of
these productivity-enhancing systems in the construction market."
Steve Murphy, a contractor
based in Orion, IL, says his experience includes drilling tools
for mining projects. "They became almost completely computerized,"
says Murphy. "That offered many benefits, but it felt unusual
not to be in complete control of the tool I was working. From that
experience I can understand why operators of machines like excavators
and graders feel they are missing something when instruments take
over. Some people make fun of operators talking about the feel
of their machines, but even car drivers understand what they mean.
It's not the technical aspects of the machine, it's the
feel." Other contractors say they cannot explain their
relationships with their machines "without sounding corny"
but that is the same concept: that the machine and operator are
one unit, not two competing entities.
"The market for
machine guidance and control products has seen relatively low
penetration rates to date," observes Mark Nichols, general
manager of Caterpillar Trimble Control Technologies. "Over
the past three years, customers who have adopted the new 3D machine
control technology have realized significant benefits, with productivity
enhancements up to 30%, reduced rework, and the virtual elimination
of certain steps in the construction process. By integrating this
technology into the design of its machines, Caterpillar will offer
its customers an innovative way to further enhance their productivity
in the field."
Some professionals have
a problem with the words control and guidance. Does
guidance imply that there is something helping the operator?
Does control indicate the operator is overruled or becoming
obsolete? "You will never totally replace the human mind, which
is required for decision-making and reason while you are working,"
states Dan Klug, excavator expert at Bobcat. "There are remote-control
machines available today, but often they are intended to keep the
operator out of harm's way. They still have operators. That's
just my opinion. Engineers may think differently." He is supported
by Leroy Anderson, also at Bobcat in North Dakota. "How can
you automate the thinking that's required when digging in touchy
situations?" asks Anderson. "Those who say that an operator's
human brain and decision-making are not essential to the running
of an excavator, dozer, or grader sound as if they themselves have
never run one," remarks Jeff Munsell, a hydraulic expert for
Caterpillar in Montana. "They seem to have forgotten the daily
aspects of the work, the small events that demand quick human involvement.
For everyday jobs, even with help from instruments, your operator
is a vital part of the project's success." Many owners
and operators of graders, excavators, and loaders agree. From these
comments, we have learned to differentiate clearly between machine
guidance and machine control. The terms are not interchangeable.
Contractors have been
using instruments that guide their excavators and graders but, to
many, the phrase machine control implies that something apart
from a human operator is running the equipment. Some years ago there
was a site where some "empty" Komatsu excavators were
controlled from a remote station because the earth they were moving
was hazardous and human operators were not allowed near it. That
application and its solution were unusual, understandable, and ingenious,
similar to demolition machines that can be remotely controlled at
hazardous sites.
Improvements in Productivity
"Our productivity
doubled," reports Arthur Hatch, engineer for D&C Construction
of Rockland, MA, referring to his use of a Topcon RT-Sa dual slope
laser transmitter. His company performed grading for the Braintree
Dam reconstruction project. "I think the instrument paid for
itself in three months of that job alone." At the Boston Central
Artery project, also in Massachusetts, use of the same type of instrument
enabled workers for joint venture Slattery, InterBetton, White and
Perini to reduce setup time by as much as 75%. "And the grades
matched every day," says Ralph Ghosn, chief engineer for the
joint venture. In Austel, GA, where the site covered 800 ac., the
Topcon RT-Sa allowed Marty Goodsen of Driggs Inc. and his team to
grade almost 35 million ft.2 with the axis lined up perfectly.
The foreman says he finished the subgrade job (for the Norfolk Southern
Railyard) two days ahead of schedule with the control mounted on
a Cat 14-H motor grader. The Georgia contractor also mentioned easy
setup, and the production increase was estimated at 60%. Those applications
are quoted as examples of machine control, but the machines were
not traveling around the sites on their own, and they did not put
any operator out of work. "Our 3-Dimensional Machine Control
puts the future of machine control to work for you today,"
states Topcon. "Less initial staking is required, with restaking
and conventional stringlining no longer necessary. The result is
fast, fully automatic grade control with accuracy."
While recognizing the
Topcon system and its proven benefits, it is most likely that the
control is of the results (the grading) rather than of the machine.
The system does not eliminate the need for an operator, nor is it
intended to do so. Most contractors equate machine control with
remote control, which implies that nobody is in or on the machine.
When remote-controlled trench compactors are used, there is no worker
in the trench with the machine; there is a worker, above the trench,
managing the remote controls for accuracy and productivity.
Similar to the Topcon
instruments is the Javelin series introduced by Laser Alignment
(Leica Geosystems). "The Javelin and the Javelin-S are dual
grade lasers," explains Dan Dykhuis, product program manager
for Laser Alignment. "The Javelin provides up to 20% grade
in both the X and Y planes and features a high-speed rotation for
accurate, smooth blade control. It has an onboard battery pack and
an LCD that the user will find easy to use. The Javelin-S provides
up to 50% grade in either the X or Y planes. It has an angle-setting
feature and an automatic line-finding feature that will set the
axis precisely to the control points." Both Javelins offer
one-touch adjustment (for windy conditions), fast steep-grade setting,
and a grade "swap" feature that reverses the grade in
one axis for such applications as road crowns. "The Javelin,"
adds Dykhuis, "can be combined with our GPS system to provide
the ultimate 3D control system."
Often it's the technological
terms that put contractors off new products. Younger workers are
more comfortable with the instruments and theories behind machine
guidance and control systems, but older professionals should remember
that they were the ones, as youngsters, who propelled many of the
features and benefits in machines that we take for granted today.
Manufacturers' representatives were knowledgeable and helpful
when asked questions that betrayed the askers' ignorance.
To reinforce the statement
that operators will not become obsolete and to offer a solution
for the problem of a worldwide lack of skilled and motivated personnel,
these words from Sir Anthony Bamford, chairman and CEO of JCB, might
be helpful: "One aspect, sometimes ignored, is that the skilled
operator or worker is becoming the most expensive item at a construction
site. The machines themselves may soon be perceived as the lower
expense. What may be ideal for a contractor is the availability
of several machines at a project–a backhoe loader, skid-steer,
excavator, and telescopic handler, for example–with one or
two operators who can run them all efficiently. I think users of
construction equipment must address the cost of labor and its level
of importance in the overall cost of doing business. Equipment that
gives savings in labor costs will become most important in the coming
years." Today's instruments for machine guidance and control
are included in that "equipment that gives savings in labor
costs." (See the article by Daniel Brown on the subject in
the May/June issue of Grading & Excavation Contractor.)
Machine Control Systems
from AGL Corporation can be manual or automatic. With both versions,
there is an operator in charge. The laser transmitter emits a beam
for the laser receiver to detect as the machine moves across the
job site. The operator sets the blade at the desired elevation by
placing the cutting edge on the reference stake. The operator then
adjusts the mast or receiver until an on-grade signal is received,
meaning that the equipment is ready. The operator monitors the display
and uses the equipment controls to manually maintain the on-grade
signal. The automatic versions operate the machine's hydraulic
systems, enabling the laser to control the blade. When using an
automatic system, the operator can simply switch to the auto mode.
For preparation at a construction site, this kind of system virtually
eliminates grade staking, making for a faster job. A machine control
system is similar to having a grade checker sitting on the blade.
Not only does it speed the operation, it also prevents material
waste. In excavation, there is no overexcavation, fewer fill overages,
and a safer performance from the machine and workers. The precision
of a laser-controlled job allows better placement of the sub-base
materials and can prevent concrete overages. This kind of machine
control has been successful for drainage projects and levee work
too.
Project Size Seems
Important
Most of the construction
projects noted as examples of good machine guidance were for airports,
highways, and industrial building sites; relatively few were everyday
jobs, such as the building of a single house, an extension to a
gas station forecourt, an extra classroom, or short street repair.
Size seems to have played a significant role in the acceptance of
guidance and control technologies. One contractor says his system
paid for itself "in three months on that job alone." Another
reports excellent productivity improvement at a project that involved
multimillion square feet of soil. Jobs that take three months or
involve 1 million ft.2 of ground are rare.
The contractor whose
work comprises mostly small jobs should not forget that skid-steer
loaders can benefit from the instrumentation. We have always thought
of excavators and graders as large machines moving large amounts
of earth, but much of today's grading and excavation is done
by small equipment, such as compact excavators and skid-steers–the
sort of machines you might expect from Kobelco, Takeuchi, ASV, Bobcat,
Gehl, New Holland, Case, Terramite, Deere, Mustang, and Caterpillar.
Grading for driveways does not require a big excavator, and the
contractor hired to do it might not own one, but that should not
deter him from investigating the guidance equipment available. "Fast
setup makes a big difference, especially on a small job," says
Rick Liske in Eldridge, IA. "If setting up instrumentation
takes as long as the whole job without the instruments, you're
not going to use it." The Laser Horn Mast from Montana Mast
Company is designed specifically for skid-steer loaders. It has
been successful for grading inside buildings and those jobs in confined
spaces where a skid-steer might be the only machine capable of maneuvering
efficiently. "It's a complete skid-steer leveling system
for about the same price as many machine control receivers alone,"
states Chuck Kleffner, president of the company. "It is simple
and installs in minutes. With this system, the skid-steer operator
can reduce job time while increasing accuracy. We have been told
it saves money in both labor and material." When this system's
Agatec MR200 receiver is mounted on equipment, its dampers on the
housing clamps minimize the effects of machine vibration to keep
the readings consistent. "The receiver for the Laser Horn Bullseye
3 360º offers three accuracies for the user to select the most
appropriate to a particular job, from rough grading to fine finishing,"
adds Kleffner. "It can be moved from machine to machine and
works with any rotating laser. The user gets a perfect grade at
the first pass. We've seen it used for parking lots, floors,
sidewalks, and home-building sites."
Related Developments
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| G700B
series motor grader cab |
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| The
Laser Horn Mast is useful for grading inside buildings and confined
spaces. |
The speed of completion
and accuracy of depth and distance are not the only aspects of grading
and excavation that benefit from extra products. The instruments
that produce efficient machine control and guidance are linked closely
with those that help in ground preparation for the contractor. Anything
that helps win the bid at a good profit must be considered. Programs
such as Trimble's new Paydirt RoadWork software system allow earthwork
estimators to digitize existing, proposed, and substrata surfaces
of the cross-sections to calculate the necessary excavation, stripping,
and substrata volumes. For heavy, highway, and earthmoving contractors,
the accurate calculation of volumes is critical to success and profitability.
Manufacturers of excavators,
graders, and dozers point out that products for guidance and control
of their machines are made by others. They are products manufactured
by independent companies to enhance the performance of standard
equipment. But don't forget the standard equipment. The manufacturers
have introduced systems into their earthmoving machines that give
today's operator good control. Volvo's Automatic Sensing
Work Mode comes to mind, along with Kobelco's NeuralNet Command
System and Case's Pro Control System.
As noted earlier, there
might be 300,000 machines in the US that can benefit from machine
control technology. Those who own them should talk with the distributor
or manufacturer of the current equipment to see if they recommend
any new technology for better earthmoving results.
Whether you prefer to
call them instrumentation control or guidance tools, the consensus
is that they can make jobs (even quite small ones) more efficient,
accurate, and profitable without putting skilled operators out of
work. Keith Mitchell, who has owned a contracting company and done
excavation, grading, and reclamation work in several Western states,
is thinking of retirement. "If I were starting out, I would
go out and buy those products for machine control at once. At this
stage in my career, it would not be worth the expense but, with
a lifetime of work ahead of me and my excavation equipment, I would
not hesitate." Mitchell's crew is, most frequently, himself
and his wife Marcia, both running excavation or grading machines.
"I have seen other contractors using the instruments, and it
is hardly believable how well they perform and how they cut down
on rework and the number of workers required."
It was the savings in
labor that impressed Richard McCoy, based just south of Memphis,
TN, and with experience in Alabama, Mississippi, and occasionally
other Southern states. His specialties have been the ground preparation
and erection of steel buildings. "I've heard others assure
their customers that a site is level and graded properly with old-fashioned
stringlines and several workers holding stakes, but I've never
seen accuracy as good as that provided by laser instruments for
the grading machines," relates McCoy. "Nobody likes to
see skilled workers made redundant, but I don't think any skilled
employees will be lost. The control systems make up for the errors
we used to have from unskilled or uncaring workers satisfied with
second best, and I think that helps both the contractor and the
customer. The most amazing success I have seen was when the dozer
of another contractor managed to work the curves and slopes for
a project that involved complicated drainage. The operator managed
it all in one pass. It was incredible!"
Frequent contributor
Paul Hull writes on construction and environmental topics for several
international magazines.
GEC
- September/October 2002
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