Теги: engineering construction building application to construction dudley knox library
Год: 1999
Текст
Calhoun: The NPS Institutional Archive
DSpace Repository
Theses and Dissertations
1. Thesis and Dissertation Collection, all items
1999
Laser technologies application to construction
Shepard, Glenn A.
Monterey California. Naval Postgraduate School
http://hdl.handle.net/10945/8610
This publication is a work of the U.S. Government as defined in Title 17, United
States Code, Section 101. Copyright protection is not available for this work in the
United States.
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DUDLEY KNOX LIBRARY
"GRADUATE SCHOOL
MONTEREY CA 93-943-5101
NA\
LASER TECHNOLOGIES APPLICATION TO CONSTRUCTION
By
GLENN
A.
SHEPHARD
A Report Presented to the Graduate Committee of the Department Civil
Engineering in Partial Fulfillment of the Requirements for the Degree of Master
of Civil Engineering
University of Florida
Summer 1999
J4
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naK£N0X UBR
ysrsssg**
Abs tract
'
Discovery
on
technology
control,
looked
to
main
the
field office
project
cost
between
focused
subject
this
construction
information
-
flow
and program management.
improve
computer
and
more
the
Hypermedia),
New research
and machine
collection
objective data
office
(via
and
element,
finite
applied
on
focus
importantly,
control
by applying
portable laser technologies at the project site and linking
collected
computer
data
between
work center supervisor/foreman.
managers
to
concentration
at
project
the
linked to Global Positioning System
real-time,
for
picture/modeling.
applied
devices
cuts/grading,
and
Resultant
site.
technology allows
(GPS)
construction
equipment
increases productivity
site
(3-D)
measuring
laser
data
control
and
permits
(bcy/hr)
,
exact
saves labor,
and when combined with night vision technology allows
night
operations.
Limited
the
productivity
optimal
three-dimensional
Further,
to
office
This real time data allows
realize
immediately
areas
field
the
cost-benefit
ratio
for
research
shows a relatively low initial investment can produce gains
up
to
9
times
during the
short-term financial gain,
of
this
technology
first
the
improves
year.
In
addition to the
reliance and consistent use
the
firm that employs such and effort.
competitive
edge
for
any
Table of Contents
List of Figures
iii
Introduction
1
Issue Identification
2
COMPUTERS AND LASER SCANNERS
4
Technology Gateway
4
Construction Productivity
8
Cost Benefit
11
The Future
14
LASERS
17
Background
17
Surveying and Global Positioning System
20
Concrete/Paving Screeds and Finishing
23
Construction Machinery and Equipment
27
NIGHT VISION TECHNOLOGY
32
Night Vision Goggles
32
Earthwork at Night
35
VIRTUAL REALITY
37
CONCLUSION
38
RECOMMENDATIONS
39
BIBLIOGRAPHY
41
List of Figures
Figure
1.
Most prevalent CPU seed for specified years
4
Figure
2.
Most prevalent CD-ROM speed for specified years
5
Figure
3.
Most prevalent modem data transfer speed for
specified years
5
Figure
4.
Construction project information flow chart
9
Figure
5.
Laser type to construction application matrix
19
Figure
6.
Typical laser surveying equipment
20
Figure
7.
Hand screeded floor profile
24
Figure
8.
Laser screeded floor profile
24
Figure
9.
Laser actuated leveling concrete screed
25
Figure 10.
Fully automatic laser controlled excavator
28
Figure 11.
Fully automatic laser controlled bulldozer
29
Figure 12. Manual laser grader control system
Figure 13.
Small arms night firefight
in
30
35
s
.
Introduction
the construction industry has been the brunt of
For years,
The latest edition of "The
jokes among the general public.
Jobs
Rated Almanac"
247 tr
out
of
250
job
career
possible
and
lumberjacks
fishermen,
the
ranks
construction worker
as
ahead
choices,
field
oil
of
only
This
laborers.
negative perception may be from the construction industry'
inability
dynamic
to
nature
collection
of
the
excessive
reputation,
varied
effectively
and
and
data
often
plan
forecast,
involved
processes
and
costs,
management
late
are
results
that
due
the
to
in
completion.
difficult
activities
unique
react
and
poor
Data
the
to
comprise
each
project
Generalizing,
construction management tends to mainly focus
on data collection processes and data management between the
main construction office and the project field office.
And,
what remains is an informal and most often verbal exchange
between the work face to and from the project field office;
thus,
critical
information
project
misinterpretation several
times
over.
is
This
subject
to
research will
demonstrate the use of current technology by which objective
data is transferred between the work face and field office.
The
current
research
will
focus
on
laser
technology
natural harmony with computer and night vision technology.
1
in
Issue Identification
Applying the latest laser and computer technologies to data
collection
from
and data management
field
the
processes,
office
optimizes
wasted
reduces
from
work
the
objectivity
the
and
effort,
face
reduces
to
and
of
the
excessive
The objective is to improve the competitive edge for
costs.
construction firms.
Now,
technological
the
potential is Hypertext.
beginning
optimization
this
Hypertext driven data systems are
This particular advancement is what drives the
everywhere.
This process allows the user
easy surfing of the Internet.
to
for
navigate by clicking on colored text which is linked
particular
data
base
hand-held personal
or
interactive
computers
(PCs)
computing power of a basic desktop PC.
widely used today
control,
Lasers
from point
sale
of
Portable
databases.
are
a
prevalent with
the
Laser scanners are
(POS)
,
inventory
to
and to graphical scanning.
applied
cuts/grading,
labor cost.
to
construction
increases
equipment
productivity
permits
(bcy/hr)
,
precise
and
saves
Combining night vision technology, specifically
Night Vision Goggles
(NVGs)
,
with laser controlled machines
will allow for productive night operations without the need
for temporary lighting or portable light plants.
It's time
s
that
combination
of
construction jobsite.
these
three
items
apply
to
today'
COMPUTER AND LASER SCANNERS
Technology Gateway
Computers have enjoyed tremendous
growth
in
this
industry
is
best
growth
since
The
1980.
illustrated
by
graphs
showing exponential performance growth of critical computer
Below (Figures
hardware system components.
graphical
vs.
representations
illustrating:
Time, Average CD-ROM Maximum Speed vs.
1-3)
are three
Average CPU Speed
Time,
and Average
Modem Transfer Speed vs. Time.
AVERAGE CPU SPEED
1980
1982
1986
1988
1990
1992
1994
1996
1998
Time - Years
Figure
1.
Most prevalent CPU speed for the specified year
(Pen Computing,
1998)
AVERAGE CD-ROM SPEED
1998
1990
1980
Time - Years
Figure
2.
Most
CD-ROM
prevalent
indicated year (Pen Computing,
speed
(max.)
for
the
1998)
AVERAGE MODEM TRANSFER SPEED
60000
*
50000
D
40000
0)
30000
a.
20000
10000
-+-
1
980
1982
1986
1988
1990
Time
Figure
3.
-
1992
1994
1996
1998
Years
Most prevalent modem data
specified year (Pen Computing,
1998)
transfer
speeds
for
.
At
issue
with
today'
computer
s
will
industry;
performance growth in hardware continue?
industry
consumption
computer
the
growth,
hardware
aforementioned
As a consequence
physical
This
trends.
and
power
with
the
size
consummately
deceased
have
exponential
comparison
will
be
A specific development to come out of the
discussed later.
rise of the computer age was Hypertext.
hypertext
In 1991,
was defined as a "database system of text and graphics that
allowed the reader to jump from idea to idea depending on
one's
interest"
which is
linear
(Williams
-
vice
1991),
beginning to end.
traditional
Before the
reading
Internet,
hypertext was used as an interactive data access tool.
By 1993, Hypertext technology had changed dramatically.
example,
the
Evaluation
United
(T&E)
States
contracted
Navy
scope and methods
for
Navy
received
a
categorized
and
the upcoming T&E of
their prototype Modular Elevated Causeway System
The
Test
for
For
hypertext
(ELCAS-M)
program
that
enveloped plans and specifications with the Navy's specified
performance requirements.
1995,
During the actual T&E in April,
an inspector assigned to the tractor trailer turntable
located at the end of the constructed causeway with pier sat
in
a
driving
storm
accessing,
from
his
laptop,
plans,
specifications,
inspection forms and photos of the turntable
components.
The
inspector
placed
additional
digital
pictures
inspection
completed
on
to
document
The
inspector
forms
performance of the components.
Clearly,
Navy received objective data.
the
He did not carry voluminous
only took some reference notes.
specifications and drawing sheets,
documents.
Further,
or Navy test requirement
the data from the T&E was analyzed and
easily downloaded
into
the
completed with
staff
of
four
"a
remarkable productivity advance
a
months after the test
-
final
report.
and
ready
The
report
was
for
review
two
from a process that typically took a year with a similar T&E
effort." (NSWC, Carderock 1995)
From
here,
computer
we
and
will
laser
make
a
scanning
construction productivity.
transition
technology
effects
of
improvement
on
into
Construction Productivity
Project Manager
Ginger Evans,
Airport,
School
and the
described
a
Airport
Fort-Worth
the
in
with
(DIA)
Airport
(DFW)
the
"information
construction
same
time
access
in
information
and
productivity
made
was
coordination,
workers
communication
completion,
chain
DIA
construction,
communication,
10,000
of
filtered
on
site
down
to
at
command
was
every
20
of
prior.
years
years.
or
verbal
level.
possible
a
to
successive
by
(Evans 1998)
many
through
With
construction output,
task
communicating
task
and
resource
and
The
was
And,
and scheduling problems.
peak
the
critical
flow
suffered
workers
non-completion,
at
speech in
representing
-
improvements made to computer capability."
During
a
construction
completed 20
doubled construction productivity rate
accelerated
Florida
of
which was twice the size of DFW,
stated that DIA,
completed
University
Construction,
Rinker
E.
She compared the construction of the Denver
International
She
M.
similar productivity increase during
November 1998.
Dallas
Denver International
Distinguished Lecturer,
1998
Building
of
the
for
problems
therefore
DIA
the
up
subjective
management
project
computer systems focused on obtaining construction data at
an intermediate level
system,
the
data was
(project
field office)
.
Once in the
considered to be objective,
but
that
.
data
changed many
was
Below
field office.
times
(Figure
over
4)
from
is
worker
the
to
the
typical large project
a
information flow chart:
Resource Management
Computer
Input
-
Operations
Considered an objective
data delivery system
Verbal
-
Highly subjective
Figure
Information
4.
flow
chart
distinguishing
between
objective data input sources/users and subjective data input
sources/users
Driving
users
is
out
the
subjectivity
subjective
data
optimizing
is
greatly
sources
goal.
helped
This
by
and
subjective
goal
to
applying
computing assets into the work face arena.
drive
data
out
portable
Today,
13-pound laptop computers of
have given way to
6
a
ounce hand-held PCs.
couple of years
And,
a
ago
decrease in
computer component power consumption coupled with lithiumion battery technology has contributed to increased computer
smaller hand-held computer
capability and to
the
abundance
of
portable
micro-computing
sizes.
technology,
With
the
construction industry can optimize objectivity and minimize
wasted
effort,
additional information.
work face effort were
initial
investment
back
call
i.e.
for
clarification
or
The cost-benefits of this objective
researched to be up to
over
first
the
year.
9
This
return on investment discussed in the next section.
10
times
the
expected
Cost-Benefit
revealed
Research
for
$250,000
construction project
report
this
that
according
to
goals.
could
he
his
for uncertainties he
The
total
everything
control;
within
plan;
lumber,
For all
material
project
where
a
cost
The project manager did not realize any
totaled $150,000.
problems
completed
recently
a
schedule
and
proceeded
cost
control
he ordered about 5% extra quantity
categorized as "waste and shrinkage."
lumber cost was $80,000.
$4,000 worth of
Thus,
lumber was ordered above what was required.
The project manager introduced a bar code laser scanner and
mandated the uncut lumber storage area scanned once
The
collected data
lumber
($4000)
was
lumber
saw his
90%
his
of
walking off the
and noticed
thereafter.
week,
was
$400.
for
15
area)
The
storage
The
equaled $3600.
the
a
steep
total
and only
10%
was
unsecured and located 20
area
drop
The cost of
cost of project
minutes each week
.
additionally ordered
job;
feet from a busy city thoroughfare.
area
week.
The project manager looked out his window
actually waste.
and
showed
a
potential
(time
savings
in
He secured the lumber
unaccounted
the bar
lumber
laser scanner
code
time was one person's
to
scan the
were
90%
each
time
lumber storage
of
$4000,
which
That potential savings represented 1.44% of
project cost.
Finally,
11
the
Cost/Benefit ratio
for this particular effort was 9.
objective
how
data
revealed
a
This example illustrates
problem
that
easily
was
mitigated, and provided opportunity to achieve up to
times
9
return on the initial investment.
The above cost-benefit example involved materials,
noted here that motivation
and it is
optimizing the project was
for
not self-actuated by the project manager
(PM)
-
the PM was
told of this savings potential.
The following example examines the benefit from objectively
reported productivity on
in
Puerto Rico.
asset
quantities
Due
island setting,
the
to
were
linearly scheduled paving project
a
The
fixed.
pothole replacement then
set completion date was
consisted
3^-inch overlay over
a
wide existing highway for
project
8
miles.
equipment
the
a
of
foot-
40
While the politically
obtainable at the beginning of the
project, two weeks of rain at start up required the schedule
to be compressed.
Initially,
per day.
to
a
the recorded overlay production rate was
workday
change
from
10
hours/day
6
week.
No
other
changes
12
to
15
days in a row,
rate dropped to 0.65 miles per day,
next
mile
The overlay rate soon slipped to 0.75 mile/day due
Consequently, after working for
the
1
hours/day.
the overlay
where it remained into
were
made
to
affect
productivity;
on the
and thus,
last day the project was H
mile short of completing.
Why was
there
date?
A
error
lack
of
information
was
at
information
did
not
achieving
in
objective
reporting
productivity
of
Intuitively,
fault.
illustrate
clearly
completion
original
the
the
the
provided
scenario
to
managers.
Everyone involved physically saw the production
rate fall,
but their subjectivity
meant
they
that
could
not
(individual and combined)
forecast
gradually fading productivity rate.
the
project
hand-held PC,
superintendent
reported
end
the
In
result
retrospect,
production
of
a
should
data
via
cause of the production rate decline would be
objectively and explicitly linked to more over-time per day
combined with successive workdays without
a
day off.
The
objective
completion
date
result
would
have
shown
the
slipping beyond what the crew was being held to.
two
examples
demonstrate
potential
savings
computer and laser scanning technologies.
13
from
These
applying
The Future
To
some
degree,
construction
comparative
growth
of
following
construction
provides
corresponding
Evan's
Ginger
effort
DIA
presupposes
productivity.
construction
But
computing
major
DFW
and
application
airport
exponential
quickly,
the
milestones
with
selected
years
in
since 1950:
Year Computer Age
Construction Application
1950 Big Mainframe
Complex weapons systems
1970 Initial PC development
Some construction data base
management
1980 Desktop PC
Database management and
manipulation,
Forecasting, Computer Aided
Design (CAD)
,
and Word
processing
1990 Micro-computers/Laptop
Simulation,
Integrated database
management, Database links, and
Internet
14
1998 Portable Age
-
Hand-held PC
Virtual Simulation,
Digitized scanning,
Voice Recognition
and imagery
The
shown
trend,
illustrates
above,
portable
type
PC
computing being pushed down to the individual on the go,
the
More
field.
with
importantly,
operating construction foreman.
to
an
From cost benefit examples,
can significantly out
the benefits
impact
less
in
distance initial costs,
plus portable computer technology cost is minuscule compared
to many project cost.
philosophy
macro-economic
Further,
employing
supports
portable microcomputers for innovation by supply and demand
driven
innovation.
regarding
their
projects
have
Construction
with
experience
stated
construction
innovative
"problems"
that
professionals
industry
construction
drive
innovation and owner's demands dictate innovation
added)
and
(Nam
Tatum,
et
al
1992)
The
.
comment emphasizes and captures demand-side
innovative
process.
material
cost
surfaces
the
reduction
The
previously
from
a
often neglected
construction
innovation
must
-
factors
in
the
project
scanner
example
supply-side
factors
This two-factor system
be
constructors in search of optimization.
15
aforementioned
discussed
code
factor
affecting construction innovation.
of
bar
(emphasis
clearly
defined
to
From
here,
technologies
the
and
research
their
will
focus
application
industry.
16
exclusively
to
the
on
laser
construction
LASERS
Background
Lasers
frequently
are
in
A
news.
the
medical
report
describes how they're used for delicate procedures such as
repairing retinas, removing tattoos or burning tiny holes in
the heart.
An industrial journal reports on lasers cutting
A photographer displays
intricate shapes out of titanium.
collection of holograms shot with
In fact,
a
a
laser he built.
lasers are used for diverse applications.
The one
thing these uses have in common is the need for remarkable
precision.
for
fit
That
need for precision made
surveying.
Now,
other construction chores.
have
their
use
is
lasers
being
natural
a
expanded
Before we examine those,
to
let's
quick history lesson.
a
Lasers were invented in 1959 when it was found that an atom
in
an
excited state would shed
photon
of
the
spontaneously
same
emit
energy
before
a
level
photon when struck by a
the
as
returning
to
photon
the
it
ground
would
state.
These two photons would then provide the energy
for
excited
with
atoms
to
shed
their
original photons.
17
photons
in
phase
other
the
.
imagine
Simply,
Imagine
scattered on it.
with
table
pool
a
randomly
balls
the
pool hall shark setting up the
a
cue ball and hitting it so that it strikes any other ball.
These two balls now go hit two others.
four
every ball
Soon
others.
started with one moving ball.
thing
is
pocket.
laser
that
a
This
process,
Emission of Radiation
name.
put
ball
,
by
what gave the
is
the
in
Amplification
Light
(LASER)
every
all
it
side
Stimulated
laser
its
The output of a laser is light that is directional,
monochromatic
intense,
light
will
and
really remarkable
the
Now,
strike
four
motion,
in
is
These
waves
are
(usually
synchronized
red)
,
because
coherent
and
the
photons
are
(the
in
phase)
In the
cheaper,
years since lasers were invented,
40
smaller and more reliable.
they've become
Additionally,
you can
build a basic laser with parts from an electronics store or
science supply house.
Figure
5,
below,
application matrix.
depicts
laser
a
type
to
construction
It is from here that further discussion
will proceed.
18
/of
/J?
A?
X
Earthmcving
Paving Operation
Site Modeling (3-D)
Management
Data Collection
Safety Detection (Cranes)
Vteldino/Cutting
Crane Operation
Figure
Note:
5.
//
/
X
X
X
X
X
X
X
/
X
X
Concrete Finishing
Material
//
/J
Laser Construction Application
Surveying
/r
X
X
X
X
X
X
X
Laser Type to Construction Application Matrix
Safety
Detection
(cranes),
Welding/Cutting,
Operation applications will not be discussed.
19
and
Crane
.
Surveying
Surveyors have used lasers for years. The better models are
accurate to within plus or minus 1/16 inch over 100 feet.
typical package
internal
system,
the
laser,
a
tripod,
and grade rods to hold the sensors.
sensors,
an
includes
stabilizing
to make
while in use.
it
mechanism,
called
one
A
or more
The laser has
a
compensation
resistant to shock and ground vibration
See Figure
6
for a representative surveying
component
A new development
mounted lasers.
in
surveying
is
the
use
of
aircraft-
A laser unit is attached to the underside
of an airplane or helicopter and transmits
its beam toward
the ground.
Figure
6.
Typical
Laser
Surveying
Navigation Ltd., 1999)
20
Equipment.
(Trimble
Positioning
correlate
units
on
point
pulse
each
ground
the
and
aircraft
A
position.
plane's
the
to
the
in
computer combines the position and laser data to produce a
three-dimensional
map
(3D)
the
of
Accuracy
ground.
is
maintained via Global Positioning System (GPS) technology.
map
This
can
ground
show
aboveground
features
such
buildings.
Compared
to
or
with survey points
results can be obtained in
all,
few
months
it
might
take
(TOPCON Laser Systems,
Another
for
methods,
the
spaced
few
accuracy.
a
Best of
"few hours rather than the
a
a
two-person
survey
crew."
1999)
construction
emerging
and
lines,
survey
feet apart and yielding 4-inch vertical
include
can
it
power
trees,
as
traditional
are more precise,
results
features,
scanning and modeling system.
developed by Cryra Technologies,
application
is
A system
currently being
is
Incorporated.
a
3D
laser
A portable,
auto-scanning laser and PC system allows collection of up to
800 as-built points per second from surfaces up to 110 yards
Collected
away.
system'
s
points
software,
l/50 th of an inch.
in
to
are
a
3D
immediately
model
with
converted,
an
accuracy
via
of
The system's software allows collected
data to be exported to popular CAD and rendering software.
The
innovative,
pulsed
laser
21
(eye-safe,
Class
II),
has
advantages over conventional fixed-beam lasers.
high power of each pulse allows
the operator
First,
to
the
conduct
survey without the use of targets or reflectors.
a
Part of
the emitted laser energy is naturally reflected back to the
instrument by the object being measured,
not
perpendicular
to
the
incident
even for surfaces
laser
beam.
This
reflector-less aspect also allows for measuring objects that
are inaccessible,
such as mine walls or suspended mechanical
system components, or for hazardous locations like highways,
airports,
and hazardous waste/materials where disruption to
operation is eliminated.
22
Concrete and Paving Screeds and Finishers
A
common
finishing
Houghton,
application
for
paving
and
Michigan,
technology
laser
operations.
claims
Somero
their Model
S-240
is
concrete
Enterprises,
screed
laser
can place up to 50,000 square feet of concrete a day or 240
square feet in
estimated
that
one-minute pass.
single,
a
a
crew
with
a
At best,
diameter
48-inch
finisher can complete 32,000 square feet per day.
1986)
The
productivity
machine is 38%.
floor.
Figures
increase
Additionally,
7
and
8
the
of
it
is
machine
(Walker,
laser-placing
the end result is a flatter
illustrate
floor
flatness
(FF)
measured in inches over the plane surface in yards.
While
the floor profile deviations of ^-inch over 10 yards
for a
hand screed floor appear to be insignificant, created demand
for near perfect floor flatness will occur.
computer
produce
of
electronics
faster
and
manufacturing
produce
a
better
Perhaps certain
companies
quality
resulting from a near perfectly level concrete slab.
9
shows a typical laser controlled screed.
23
could
product
Figure
HAND SCREEDED FLOOR PROFILE
0.4
=
0.2
°
-
—
8- -9
-0.2
4£-
-0.4
Yards
Figure
7.
Hand Screed Floor Profile
over plane measurement in yards.
-
deviation in inches
(Laser Screed Ltd.,
1999)
LASER SCREEDED FLOOR PROFILE
8
—
9
4-0-
-0.4
Yards
Figure
8.
Laser Screed Floor Profile - deviation in inches
over plane measurement in yards.
24
(Laser Screed Ltd.,
1999)
For the average wear surface or where the concrete slab is
to be covered by another material like tile,
wood,
carpet,
or
the value of a laser screeded surface is not
warranted.
Figure
9.
Laser Actuated Leveling Concrete Screed
Screed Ltd.,
1999)
25
Laser
Application for pavement (asphalt and concrete)
is much
different than structure slabs, as users travel over the
finished surface at high speeds.
The surface imperfections
in the pavement are transferred to the user through via the
vehicle suspension system.
Laser screed use in pavement
construction mitigates the surface smoothness distortion
that the driver would experience.
Intuitively,
a
reduction
in pavement surface distortion would result in reduced
maintenance cost for both the roadway owner and the vehicle
owner.
26
Construction Machinery and Equipment
The
laser's
control.
accuracy
Graders,
also
makes
it
useful
for
machine
scrapers and excavators can use lasers to
maintain tight tolerances.
The other significant importance
of laser controlled machines is productivity rate increase.
"If a small contractor puts on a grader control system and
gets
and additional
worth of productivity,
50%
then he
is
not going to let that grader sit around for half the year."
(McGarry,
checker
1996)
is
With the grader control system,
eliminated
under
and,
grading can be accomplished in
3
rd
the
gear.
right
But,
if you're laying down
grade
conditions,
"The initial price
can scare the devil out of some people considering
system.
a
a
laser
five miles of road and
your operator is off his grade by ^-inch for the entire five
miles,
grade."
it will mean that much more rock or pavement to reach
(Harris,
1996)
Before the research continues with
exciting productivity gains,
the research must focus on the
detailed workings of such systems.
Machine control can be either fully automatic or manual.
manual
mode,
the
system
relies
on
the
operator
to
In
make
adjustments in response to lights on the laser sensor that
indicate above, below or at grade.
connect
to
the
machine's
Fully automatic systems
hydraulic
system
and
send
electronic signals that prompt the machine to automatically
27
'
make
adjustments
illustrates
a
to
proper
fully automatic
to a typical excavator.
laser
grader,
control
grade
systems
or
depth.
Figure
10
system applied
laser control
Figures 11 and 12 illustrate manual
applied
to
a
typical
bulldozer
and
respectively.
w
Figure 10.
Fully Automatic Laser Controlled Components on
Typical Excavator.
(Topcon Laser Systems,
28
1999)
a
-I
f«
Figure
11.
Conventional
Laser Control Device
Bulldozer
Outfitted
(Topcon Laser Systems,
29
with
1999)
Manual
Figure 12.
Systems,
Manual Grader Laser Control System (TOPCON Laser
1999)
Do lasers have limitations?
Yes,
slope found in common site prep,
are still confined to flat planes.
or
crown,
lasers
reasonably durable,
won't
work.
while they can handle any
and even dual slopes,
If your site has a curve
And
although
they're not hammer-proof.
30
they
If
they're
a
laser
and
sledgehammer
a
knocked
get
together
the
in
bed of
a
pickup truck, the laser loses.
Another question
compared
to
ask,
to
emerging
how well
is
technology,
Computer Aided Earthmoving System
will
lasers
such
(CAES)
?
perform
Caterpillar's
as
Caterpillar hopes
their development will "revolutionize" the mining industry.
CEAS
is
which
(CMETS)
and
part
GPS
of
integrates
technology)
positioning,
job
machine control.
robots
Mining
Cat
and
If
Earthmoving
Technology
advanced communications
machine
,
and
monitoring,
business
management
(wireless
diagnostics
software,
and
and
the day comes where machines are mere
controlled by an elaborate system of computers
and
satellites, where the operator only observes the work from a
tower with one hand poised over a kill switch,
lasers will
be decidedly old-tech.
For now lasers offer incredible precision and,
in the right
application, they can increase production exponentially.
think,
all
this because
40
years
playing around with nervous atoms.
31
ago
some
To
scientists were
NIGHT VISION TECHNOLOGY
Night Vision Goggles
The
use
see
into
of Night Vision Goggles
visible
the
night.
light
enhances one's
un-aided eye
The
spectrum and thermal
ability to
within
operates
imagers
operate
the
within
the infrared spectrum.
Night Vision Goggles operate in the
visible
infrared spectrum,
see
light
and near
amplified
both
visible
light
and
allowing one
the
near
to
infrared.
Night Vision Goggles allow pilots and observers to use the
most
aviation
important
acuity)
to
see
in
a
available
asset
low
(increased
environment,
light
visual
effectively
allowing aircrews to see in the dark with their own eyes.
There exists a misconception that one'
when using Night Vision Goggles
s
vision is restricted
(NVG)
due
technology 40-degree field of view limit.
normal unaided eye has
In
most
Therefore,
this
states,
continuing
a
to
current
the
Consider that the
visual acuity of 20-200 at night.
is
classified
with
as
aircrew,
the
legally
blind.
members
"have
approximately a 200 degree un-aided field of view at night,
they
are
blind.
employing
instrument
flying with
Given
NVG'
this
s
flight
they
acuity
visual
information,
should,
proficient
32
at
in
classified
if
a
order
aircrews
are
not
be
basic
conduct
night
minimum,
to
legally
as
flight
operations
with
margin
greatest
the
safety."
of
(Skycop, 1999)
Because NVG'
vision
s
allow un-aided peripheral vision as
underneath
the
aircrew
goggles,
decreasing their field of view.
NVG's,
In fact,
members
well
are
as
not
by properly using
those same aircrew members have added 40 degrees of
20-40 vision to their 200 degrees of 20-200 vision.
More
importantly,
by
employing proper
techniques
scanning
while using NVG's, aircrew members can actually increase the
area of 20-40 vision up to 180 degrees or more.
Contrary to
Night Vision Goggles actually enhance the
popular concept,
effectiveness of airborne searchlights, while simultaneously
increasing flight safety.
does
not
The intensity of the searchlight
significantly limit
With
acuity.
NVGs can be used in urban environments,
light,
see
in
mind,
with high intensity
with minimal image "washout". This allows aircrews to
into
parks,
this
dark
areas
shorelines,
a
as
alleys,
between
buildings,
and areas that otherwise cannot be seen
using the unaided eye.
which appears as
such
NVGs are affected by "green" light,
bright blotch.
Military operations with NVGs show best visual acuity with
blue or red light sources.
or
guides,
as
a
person's
affected by red light.
Red is recommended for markers
natural
night
vision
is
not
Un-aided night vision is interrupted
33
for
some
time
white light.
(U.
after
S.
exposure
Army,
1996)
34
to
other
colored
light
and
Earthwork at Night
The
have
Navy's
been
equipment
offered
expeditionary
construction
experimenting with
night.
at
little
productivity.
Such
incentive
Figure
13
due
operations
to
a
traditionally
significant
picture
of
Seabees,
construction
operating heavy
night
is
experts,
a
losses
small
in
arms
firefight at night, where the distance from weapon to target
impact is 1200 yards.
The distance is hard to discern from
the figure.
Figure 13.
Small Arms Night Fire.
NMCB FOUR FEX,
1998)
35
(Operation Bearing Duel,
With the advent of Night Vision Goggles
earthwork production and accuracy,
improved little.
the Navy's
(NVG's),
during night operations,
The complaint from the operators was that
they "could not feel" what they were excavating, grading, or
loading.
it
at a cost - only being able
is
like
laser
The NVG's offer the ability to see at night,
a
picture.
guiding
and
There
is
no
controlling
to
but
see in two dimensions
Applying
depth perception.
technologies
the
to
Navy's
equipment combined with the NVG's will allow the "feel" to
be
perceived
by
the
operator.
The
addition
of
laser
technology will allow the to operate productively at night.
36
Virtual Reality
The day will come when machines
by
and
elaborate
and
satellites;
site
kill
where,
computers
of
the
operator
of
computers
observes
from a tower with his only control on a
Combining
switch.
machines,
3D
the
project
keyboard and
controlled
laser
modeling,
and
and night vision technologies will accelerate the
coming of such
Just
system
are mere robots controlled
think
a day.
of
the
many
new
applications
undertaken with that system scenario.
that
could
be
Man doesn't like to
work in extreme conditions like heat and cold,
Consider that man as
or confined
a
labor instrument
really operates efficiently at 70 degrees
fehrinheight and
and outer space.
50% relative humidity;
anything up or down and productivity
exponentially decreases.
(Oglesby,
Et al,
1989)
Machines have a much greater range of operating conditions.
Applications of advances in the aforementioned technologies
can only benefit society.
37
Conclusion
simulations, and continued research
There are papers, books,
aim
that
improve
to
productivity
productivity
initiatives.
construction
innovation
innovation.''
"problems"
and
demands
vision
tangible
gains
s
(Nam and Tatum,
in
technologies
in
factors
subjective
eliminate
owner'
laser technologies
addressing two
However,
(1)
s
night
and
and
Additionally,
(emphasis added)
on applying today'
term
construction
Subjectivity in data information systems derails
industry.
computer
the
in
1992)
can
for
laser
equipment and machines.
equipment
initiatives:
long
(1)
and
(3)
are
on
short
term
success:
and
(2)
The best
construction
Laser application on construction
machines
and
precise
concrete/paving placement
labor,
applications
Focus
productivity.
realize neglected supply-side innovative factors.
opportunities
.
produce
management,
database
dictate
combination with
construction
drives
drive
illustrates
guiding,
cuts
screeds,
opportunities
to
combination with Night Vision Goggles.
38
(2)
improvement
three
and
grading,
reducing
operate
at
and
required
night
in
Recommendation
Further research linking cost to field application of lasers
in earthwork is needed.
gross
productivity
earthwork
controlled
Intuitively,
equipment.
it
can be shown that
better
is
there
However,
without
is
laser
point
a
in
completing an earthwork operation where the application of
precise
curves
controlled
laser
versus
match.
equipment
increase
productivity
non-controlled equipment productivity curves
This fact must remain at the cognitive forefront for
considering
managers
laser-controlled machines.
Obviously,
using machines to work where man can or will not provides
wonderful
opportunities
to
better
society.
It
is
the
opportunities that will create the demand by customers.
Additionally,
there
need
is
for
improvement
in
better
linking technology research to practical application in the
field.
The drive to facilitate persuasive discussion using
technology to the fullest extent is controlled by cost and
associated risk with that cost.
Maximizing thinking out of
the box to optimize a firm's competitive edge as it relates
to
construction management works
that want
to
grow.
Investor's
company ought to grow;
is
viewed
as
a
tool.
39
for
those
and financiers
therefore,
survival
only
companies
assume each
investment in technology
Some
may
view
growth
in
.
.
technology industries merely leads to spillover effects into
construction,
but
the
research
demonstrates
tremendous
private construction industry innovation is being developed.
What a time to be involved in an ever dynamic era.
following
The
is
summary
a
specific
of
recommendations
specifically for the United States Navy:
•
Invest
adding
in
laser
technologies
ongoing
to
investments in night vision and computer technologies.
•
The
to
Naval
Facilities
task the Naval
(NFCES)
with
combining
Engineering Command
ought
Facilities Engineering Service Center
initiating
laser
(NAVFAC)
with
Test
night
and
Evaluation
vision
and
(T&E)
of
computer
technologies
•
The
Navy ought
Development
to
(R&D)
partner with
initiatives
effort
40
commercial
to
reduce
Research
and
duplicative
.
.
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Inc.
Caterpillar
(1999)
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Mining
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3
*r'B525l
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10/99 22527-200