标题: Higher Levels of Automation Lift Productivity for Airbus A380 [打印本页] 作者: 航空 时间: 2010-8-15 22:07:31 标题: Higher Levels of Automation Lift Productivity for Airbus A380
Higher Levels of Automation Lift Productivity for Airbus A380 Wing Assembly Process 作者: 航空 时间: 2010-8-15 22:08:01
Overview:
Electroimpact of Mukilteo,
WA, is the prime contractor for
supplying automation tools to the
Airbus plant in Broughton, UK,
which assembles the wings of the
Airbus A380, the world’s largest
aircraft. The assembly process
occurs in several phases: 1) wingpanel
assembly (Stage 00), which
employs four 165-meter-long
automated wing-skin production
lines using Electroimpact’s
E4380 riveting-bolting machines;
2) wing-panel manipulators,
which use servo hydraulic arms
to position the panels for the
next stage; 3) wing-assembly
production (Stage 01), which
uses a massive four-story-high jig
that incorporates Electroimpact’s
HAWDE (Horizontal Automated
Wing Drilling Equipment), a
portable CNC drilling machine
Higher Levels of Automation
Lift Productivity for Airbus A380
Wing Assembly Process
Electric Drives
and Controls Hydraulics
Linear Motion and
Assembly Technologies Pneumatics Service
Drive & Control profile
The Airbus A380 — the world’s largest commercial aircraft.
Challenge
Meet demanding technology
specifications for wing assembly of
world’s largest passenger aircraft.
Bosch Rexroth Solution
• Rexroth linear guides, ball screws,
runner blocks and guideways
• Servo hydraulic arms to transfer
wing panels to wing-structure jigs
• Rexroth HNC 100 servo hydraulic
controller and servo solenoid valve
Benefits
• High accuracy on machine lines
• Rexroth HNC provides position
control with seamless transition
between position and force control
• Precise, smooth travel from
Rexroth roller rail in GRAWDE
machine for drilling Airbus
undercarriage area
• High performance technology and
support, reduced process time
and hydraulically operated remotetool/
worker-access platforms. This
equipment works in conjunction
with the GRAWDE (Gear Rib
Automated Wing Drilling
Equipment) mobile system used for
attaching the undercarriage to the
lower wing.
Electroimpact collaborated with
Rexroth to provide hydraulic
and linear-motion solutions to
meet demanding technology
specifications and tight schedule
requirements. Electroimpact
needed to phase in delivery of
machinery as the facility ramped
up operations to position, drill,
rivet, and bolt the approximately
180,000 holes needed to produce
a single Airbus 380 wing box.
Thanks to a higher level of
automation, the Broughton plant
can employ a process flow model
to produce four pairs of wings
a month — the largest and most
productive wing-assembly plant in
the aviation industry.
Scope of the challenge:
The Airbus A380 is the largest
commercial aircraft in the
world, and the only twin-deck,
four-aisle jet in the air. The base
passenger design seats 555 in three
classes. The triple-decker freighter
design hauls up to 150 tons. By
comparison, the U.S. military’s
tank-transporting C-5 Galaxy can
carry only a 135-ton payload.
The scale of the A380 is huge: The
wingspan is nearly as long as a
football field — 261 feet, versus the
C-5’s 223 feet. Each wing stretches
119 feet from wing tip to fuselage;
together, they hold 41,000 gallons
of fuel, plus the landing gear. The
large wing surface area — 9,100
square feet — improves takeoff
and landing performance.
The wing manufacturing process
for the A380 consists of creating
a framework from spars and
ribs — the wing structure — which
is eventually covered with a skin of
metal panels. Spars run the length
of the wing. In addition to front
and rear spars, an immense 21-ft.-
long x 6-ft.-wide spar runs down
the center. Ribs cross the spars,
extending from the leading to the
trailing edges of the wing.
Custom-built Electroimpact HAWDE machine speeds wing-panel production.
The E4380 wing panel machine attaches stringers to the skin in the Stage 00 cell.
for Airbus’s manufacturing
team in Broughton, U.K., and
for its prime contractor for
wing-assembly automation
tools, Electroimpact, Inc.
Focusing on the design and
manufacturing of quality aircraft
assembly tooling, Electroimpact
is known for its engineering
culture — nearly 70% of its
250 employees have an engineering
degree. Engineers in charge of a
program are empowered to take
total responsibility, including
vendor selection. For the Airbus
programs, Electroimpact choose
to work with Bosch Rexroth for its
best-in-class hydraulic and linearmotion
solutions and applications
expertise, as well as Bosch
Rexroth’s distributor, Pacific Power
Tech, based in Seattle.
Stages of wing construction
“The assembly process is
done in two stages,” explains
Electroimpact’s Ben Hempstead.
“For the initial stage, which Airbus
calls Stage 00, Electroimpact
provided four lines of fixtures
for building up the upper and
lower wing panels. This is a highly
automated process in which
riveting-bolting machines traverse
the panels attaching stringers to
the skin. Virtually no manual labor
is required in this cell.
Next, the panels are moved to the
structural wing-assembly process.
The huge size of a completed
panel — up to 111 feet long and
weighing 8,818 pounds — poses
a big problem. “Using cranes
doesn’t work,” says Electroimpact’s
Ted Karagias. “The wing
panels are distorted when
suspended from the cranes.”
Panels, which consist of an
aluminum alloy skin reinforced
by stringers, are then attached
to this framework.
The panels are produced
concurrently in a separate
operation. First, skins are formed
to the proper curvature. Stringers
are made to fit that contour, then
are attached to the skin to ensure
proper shape and strength by the
E4380 machines in the Stage 00
cell. The A380’s upper wing uses
the largest single skin, which is
111 feet long.
The completed panels are then
moved to the structure for
assembly. After being loaded into
a jig, the panels are positioned,
drilled, countersunk, riveted or
bolted with titanium lockbolts
onto the pre-drilled framework.
The entire process is both labor
and automation intensive,
especially at this scale — a complete
“wing box” takes weeks to produce,
which, even so, is very fast by
industry standards.
Construction of the A380’s wings
presented several large challenges
HAWDE unit automatically drills holes
during the Stage 01 wing process without
the quality and speed compromises of
manual operations.
Stage 00 E4380 machine positioned over panel fixture.
Close-up of the rotated head of the
HAWDE CNC drilling machine used in
Stage 01 .
machines. Our design goal was
to enable one operator to set up,
load NC tapes, verify accuracy,
and configure the fixtures.”
For the Airbus A380 panelproduction
facility, Electroimpact
built four machine lines, each
with two machines for upper and
lower surface panels. Each line
includes three fixtures, where four
panels are loaded. The jigs hold
the components in accurate form
and location while the automated
machines drill, rivet, and bolt
the components together. Sealant
is applied to the components
during the jig load. No temporary
fasteners are used.
Thus after fastening, the wing
panel assemblies are complete.
No interim operations are needed
to clean and deburr. The oneup
assembly process reduces
handling damage and positioning
inaccuracies (datum errors).
The machines can install rivets
and bolts in diameters of 1⁄4
to 1⁄2 inch, with a stack range
up to 2.5 inches. Automated
cold working, hole probing,
countersink sealing, and collar
installation are all included.
Achieving high-accuracy goals
was possible, because the machines
and fixtures used many highly
accurate linear axes employing
Rexroth linear guides and ball
screws. Machine accuracy is a
function of deflections of welded
and machined components.
Typically, deflection and running
accuracy of linear guides and ball
screws add errors. To minimize
deviations, several sizes and
styles of Rexroth runner blocks
and guideways were specified,
Instead, Electroimpact devised
a multi-arm manipulator to
maintain the panel’s proper form
and provide precise positional
control while presenting the panel
to the wing structure for fastening.
The Stage 01 structural-wingassembly
process is more labor
intensive than the Stage 00
operation. The assembled skin
panels are positioned by the
manipulator into four-story high
jigs, which contain other wing
parts — ribs, spars, leading and
trailing edges. For the upper
wing, a combination of mobile
drilling machinery (HAWDE)
and manpower accessibility is
required over the large surface
area of the upper wing panels. For
the lower wing, holes as large as
1.25 inches in diameter are drilled
for bolting the lower wingskins to
undercarriage reinforcements.
Starting at stage 00:
wing-panel assembly
To manufacture skin panels,
Airbus U.K. and Electroimpact
teamed up to create a highly
automated facility.
According to Hempstead, “We
faced several challenges in this
program, namely how to bring a
fixture of stringers and machined
skin panels together in a precise
build configuration, while an
automated machine tool fastens
the components into a skin panel
assembly. At this stage, speed,
accuracy, and operator safety are
critical to this success.”
Each wing surface is comprised
of five panel assemblies, 20 panels
total. The Airbus Stage 00 facility
produces 16 of these panels.
Traditionally, these panel
assemblies were built on manual
jigs, requiring many skilled
workers to locate and drill
holes, pull components apart for
deburring and cleaning, apply
sealant, and insert two-piece
lockbolt fasteners. Panel assemblies
were then transported to a
riveting machine for final rivet
installation. Production rates
were limited by the number of
jigs in production, worker access
and speed, and hole quality and
rework requirements. Finished
panel quality was also limited
by how well the fixture held the
components in proper contour.
But Electroimpact believed there
was a better way. “Building on our
previous work for the Broughton
facility, we ended up expanding
the system’s performance
envelope and accuracy of earlier
panel production machinery,”
says Hempstead. “The result is
a new generation of wing panel
Massive, multi-arm manipulator maintains
proper wing-panel shape during transfer
to the Stage 01 jig.
because they provide excellent
performance on several axes.
Highly pre-loaded roller runner
blocks, pre-loaded ground
ball screws, and caged-ball
runner blocks were employed,
because pre-loading ensures
rigidity of the system and
thereby maximizes accuracy.
“We’re designing the machines
and fixtures concurrently with
the wing design,” says Hempstead.
“Consequently, some aspects of the
design cannot be completed until
late in the program. That means
schedules and lead times are tight.
Fortunately, we’ve been supported
every step of the way by Rexroth.
“Accurate estimation of vendorsupplied
product lead-time is
critical in keeping assembly on
schedule. I’m happy to say that
since operation began in March
2003, the Stage 00 facility has been
producing assemblies on time and
with far better speed, quality and
points is very difficult. “Basically
you have a statically indeterminate
system. The panels will twist, bend,
and kick as they react to the forces
introduced by lifting equipment.”
“To overcome this problem,
two of the six arms control the
vertical position of the panel,” says
Karagias. “The other four arms
act as slaves imparting a constant
programmed force upon the
wing panel. That way, when the
positioning arms are commanded
to move either up or down, the
load-seeking arms follow along to
maintain the panel’s form.”
Len Hathaway of Pacific
Power Tech, Seattle, WA, was
instrumental in assisting the
Electroimpact team to specify the
Rexroth hydraulic components
for the project. The primary axis
of movement is maintained in
closed-loop servo control by a
Rexroth HNC 100 servo hydraulic
controller. The HNC integrates
an SSI linear scale, load cell, and
a Rexroth servo solenoid valve.
This configuration provides fine
position control with seamless
transition between position and
force control.
According to Karagias, the
servo axis provides exceptional
control over panel position, and
the Rexroth HNC controller
imparts several important
system benefits, namely:
• Reducing the statically
indeterminate problem to a
determinate one, allowing flexible
wing panels to move as if they are
a rigid part.
• Controlling distribution of
force imparted upon the wing
accuracy compared to manual and
earlier automated systems.”
Interim stage:
install panels to wing
substructure with manipulators
After the wing panels are
produced, they must be moved to
the wing-structure jigs. Because the
largest panel is up to 111 feet long,
the huge scale creates a big material
handling problem.
To meet this challenge, an Airbus
team of Alan Ferguson, Allan
Ellson, and Jim Rowe of Airbus
called upon Theodore Karagias of
Electroimpact. Karagias headed an
Electroimpact team — comprised
of Charles Hopper, Remco Spiker,
Laurence Durack and Matt
Kerschbaum — to devise a solution.
Instead of cranes, Electroimpact
created an array of six coordinated
servo hydraulic arms that engages
the panel along its entire length.
According to Karagias handling a
wing panel with multiple support
A close up view of E4380 machine and Stage 00 jigs.
panel to control the panel’s
shape and how it is presented
to the wing structure.
• Simplifying system level PLC logic
and position control instructions.
• Allowing direct access to all
critical system components and
providing servo control via the
SSI port using analog and digital
I/O, ProfiBus, and CANbus
fieldbuses, regardless of PLC scan
rates or network speeds.
When put to the test, the wingpanel
manipulator successfully
loaded its first A380 wing panel.
“It took a lot of teamwork to create
this system,” notes Karagias. “And
thanks to great collaboration, the
pieces just fit together beautifully.”
Stage 01:
wing-structure assembly
After the wing panels are loaded
in the Stage 01 jig, two operations
are performed: 1) fastening the
wing panels to the rib-andspar
structure, which requires
automated drilling, bolting,
and positioning employing
Electroimpact’s HAWDE machine;
and 2) attaching the undercarriage
reinforcement through the
lower wing skin, which uses
Electroimpact’s GRAWDE system.
HAWDE
Based on previous successes,
Airbus approached Electroimpact
to automate wing-panel
fastening to the wing structure.
Traditionally, this task is
done by drilling, bolting and
positioning the panels manually.
Automating the process meant
overcoming several challenges
with unique solutions.
“The basic challenge was how to
transport equipment from jig to jig
between port and starboard wings,
while accommodating necessary
manual work on all vertical
levels,” says Ryan Haldimann of
Electroimpact’s HAWDE team. “In
effect, the machine tool needed to
be transported along Y (vertical)
and X (horizontal) directions of
travel, similar to a tool head in a
gigantic CNC machine.”
As a solution, the Electroimpact
team of six headed by Rick Calawa
created the HAWDE machine — a
portable unit that can travel
around a panel section by using
elements integrated into each
jig. To give workers access all
around the wing structure, the
jig incorporates “flip” flooring.
Each flip floor consists of a small
platform for worker access, which
is pivoted up when the completed
wing is removed. A single jig uses
150 flip floors, each employing
a Rexroth hydraulic cylinder
for smooth, reliable actuation.
Ultimately, four jigs will be in use,
requiring 600 Rexroth cylinders.
Because Electroimpact is
responsible for both the jig and the
HAWDE unit, an unprecedented
level of integration was achieved.
Right from the initial concepts, all
mobile elements of the machine
were integrated into the jig. To
move the 7000-lb machine from
jig to jig, a transporter crane is
used. Level-to-level movement
employs an elevator that is capable
of aligning the machine beds to
within .005 inch.
In addition to facilitating worker
access, the HAWDE unit must
drill holes in the wing where the
flip floors are located. To reach
areas of the wing where flooring
is normally located, the machine
performs a “Y-Shift,” where the
Y-column of the machine extends
above its normal position by about
one meter. This is accomplished
using a Rexroth size 45 roller
rail system for guiding, and a
Airbus A380 wing after removal from main assembly jigs.
hydraulic cylinder for lifting the
floor. Thanks to the precision of
Rexroth hydraulics, the machine
can perform shift maneuvers while
maintaining its overall volumetric
drilling accuracy.
Movement along the X axis uses
a square rail guide way and a gear
rack. All other axes use traditional
linear and rotational bearings. The
machine incorporates a number
of tools: a drill spindle capable of
up to 7000 rpm in 1⁄4 to 5/8-inch
diameters, a bolt inserter for
inserting slave fasteners, a hole
probe for measuring hole diameters
and a camera for synchronizing
the machine to positioning
(datum) holes in the wing.
In November 2003, the HAWDE
machine was put into production.
10,000 holes later, Airbus Team
Leaders note: “Manual drilling
has always involved some
quality or speed concessions.
But as far as we’re concerned,
the HAWDE is operating
without such limitations.”
According to Haldimann, “Success
like this takes teamwork. We’ve
been able to design a machine with
a high level of integration into the
jig, which makes the HAWDE very
easy to use and able to meet all
expected criteria.”
GRAWDE
Concurrent with wing-panel
attachment, Stage 01 production
also involves attaching the
undercarriage reinforcing and wing
skins to the landing gear structure.
Titanium flathead bolts up to
1.25-inch in diameter are inserted
through a stack of materials up to
four inches thick.
“Traditionally, this operation
is done manually in wing box
assembly jigs,” says Brent Thayer,
the Electroimpact engineer in
charge of automating this process.
“But manual hole drilling requires
massive drill templates and large
positive feed drill motors. The
work is physically demanding.
In spite of these large tools, the
holes must be drilled in multiple
steps to reduce the thrust loads, a
process which adds process time.
Plus, new templates are required
for most wing design changes. In
view of all the variables, achieving
the required hole quality using a
manual process is very difficult.”
Airbus U.K. asked Electroimpact
to explore a more efficient,
automated drilling method. But
designing automated drilling
equipment capable of drilling these
holes, yet permitting manual access
within the wing box assembly jig,
was a significant challenge.
“The time spent drilling in this
area of the wing is less than 10%
of total wing box build time,” he
says. “To remain cost effective, the
drilling equipment must be flexible
and mobile for use on multiple
surfaces and assemblies. They use
it, then move it.”
In conjunction with the Airbus
U.K. team, Electroimpact
developed a mobile automated
drilling system for the A380
undercarriage area — the
GRAWDE. The program involved
an extensive cutter development
effort. The machine can drill
up to 1.25-inch-diameter holes
with countersink in a single
operation and 12 different
wing surfaces in total.
Similar in design to a five-axis post
mill, the GRAWDE uses a Rexroth
roller rail for the X, Y, and Z axes.
The Y and Z axes use Rexroth
ball screws. These linear-motion
components ensure precise, smooth
travel to meet tight tolerances.
The GRAWDE machine pushes
on the A drawing showing the variable height of the HAWDE machine for jig clearance. parts being drilled
Conclusion:
The truly large scale, multi-stage
wing-assembly operation for
the Airbus A380 involves four
programs — panel fabrication,
wing-panel manipulation, wingpanel
assembly (HAWDE), and
undercarriage reinforcement
(GRAWDE) — all requiring
extensive collaboration between
Airbus, Electroimpact, Rexroth,
and other vendors.
“The goal was not just to design
machinery that automates manual
tasks,” says Ben Hempstead, “but
also to improve quality and reduce
process time. This requires a lot
of collaboration with our vendors.
In Rexroth’s case, we get highperformance
technology, but
also high-performance support
to meet short lead times and
tight schedules. That level of
collaboration gives us the boost
we need to perform at the levels
required for the Airbus A380 wingassembly
facility.”
with a specialized pressure
foot to stabilize the wing skin
while drilling. Sensors or
pre-programmed angles ensure
the holes are drilled normal to
the curved aerodynamic surface.
As with HAWDE, it was important
to integrate the machine with the
wing jig. “Over 90% of the wing
box build is manual,” Thayer
emphasizes. “So an ergonomic
design that facilitates manual work
access is a must.
“Because the machine needs to
drill holes near the factory floor
level, the top of the machine
beds are located below grade.
Bi-fold decking at the factory
floor level covers the machine
beds and provides proper
ergonomic work zones for
manual operations. Again, highperformance
Rexroth hydraulics
are used to move the floors up
to provide machine access.
“Like the other programs, the
GRAWDE has been a huge
success,” says Thayer. “It
consistently produces higher
quality holes than the manual
process, so the hard manual work
has been eliminated. Plus, it’s
easier to incorporate last-minute
design changes, because we can
avoid expediting expensive, longlead-
time drill templates.”
2007 Bosch Rexroth Corporation
Subject to change without notice.
Printed in USA.
ALL RIGHTS RESERVED
FORM Airbus (0207)
Bosch Rexroth Corporation
5150 Prairie Stone Parkway,
Hoffman Estates, IL USA 60192-3707
Telephone (847) 645-3600
www.boschrexroth-us.com作者: xf_dragonwing 时间: 2010-10-26 11:37:43
