Upload
truongngoc
View
235
Download
0
Embed Size (px)
Citation preview
1
© 2011 Lockheed Martin Corporation
Concept Development of an Automated Shim Cell
for
F-35 Forward Fuselage Outer Mold Line Control
by
Jamie Smith
A Research Paper Submitted in Partial Fulfillment of the
Requirements for the Master of Science Degree
in
Manufacturing Engineering
Approved: 3 Semester Credits
The Graduate School
University of Wisconsin-Stout
December 2011
2
© 2011 Lockheed Martin Corporation
The Graduate School
University of Wisconsin-Stout
Menomonie, WI
Author: Smith, Jamie M.
Title: Concept Development of an Automated Shim Cell for F-35 Forward
Fuselage Outer Mold Line Control
Graduate Degree/ Major: MS Manufacturing Engineering
Research Adviser: Annamalai Pandian D. Eng
Month/Year: December 2011
Number of Pages: 84
Style Manual Used: American Psychological Association, 6th
edition
3
© 2011 Lockheed Martin Corporation
Abstract
The F-35 Joint Strike Fighter, produced by Lockheed Martin Aeronautics, requires
precision control of the designed-in shim gap between the forward fuselage understructure and
the mating skin. The current manual shimming method results in excessive time and material
waste which makes it impossible to support a peak production rate of one aircraft a day. The
purpose of this study was to develop a concept for an efficient, automated liquid shimming
system and to verify the feasibility of specific components of the system. A team was assembled
to gather requirements for a production-ready shimming system, develop a shim cell concept,
and complete a cost benefit analysis to justify the need for an automated system. Gage
repeatability/reproducibility and accuracy tests were completed to verify that a non-contact
metrology system could meet requirements for structure location and surface profile verification.
Tests were performed to identify various material options and release agents for an outer mold
line (OML) control tool, and a sub-scale OML control test tool was designed and fabricated. The
results of this study provided Lockheed Martin Aeronautics the necessary foundation to verify
system feasibility and validate system components in order to begin specification development
for the procurement of an automated shim cell for F-35 forward fuselage outer mold line control.
4
© 2011 Lockheed Martin Corporation
The Graduate School
University of Wisconsin Stout
Menomonie, WI
Acknowledgments
I would like to thank my husband, Dale, for all of his support, love, and encouragement
throughout this degree process. I would also like to thank David Fly for his advice and guidance,
especially for distance learners. Finally, I would like to thank my field project advisor, Dr.
Pandian, for his valuable time, timely feedback, and improvement suggestions with completing
this paper.
5
© 2011 Lockheed Martin Corporation
Table of Contents
.................................................................................................................................................... Page
Abstract ............................................................................................................................................3
List of Tables ...................................................................................................................................8
List of Figures ..................................................................................................................................9
Chapter I: Introduction ..................................................................................................................10
Statement of the Problem ...................................................................................................14
Purpose of the Study ..........................................................................................................15
Assumptions of the Study ..................................................................................................16
Definition of Terms............................................................................................................16
Limitations of the Study.....................................................................................................18
Methodology ......................................................................................................................18
Chapter II: Literature Review ........................................................................................................20
Shimming in the Aerospace Industry .................................................................................20
Shim description ....................................................................................................20
Purpose of shims ....................................................................................................21
Industrial Automation Considerations ...............................................................................22
Automation descriptions ........................................................................................22
The benefits of robotic automation ........................................................................23
Uses of robots ........................................................................................................24
Metrology Enhances Automation Capabilities ..................................................................25
6
© 2011 Lockheed Martin Corporation
Types of metrology ................................................................................................26
Metrology and automation for assembly processes ...............................................27
Conclusion .........................................................................................................................30
Chapter III: Shimming Methodology.............................................................................................32
Concept Development ........................................................................................................32
Establish a development team ................................................................................33
Baseline the process ...............................................................................................33
Investigate existing technologies in the industry ..................................................33
Complete a CBA ....................................................................................................34
Verify System Component Feasibility ...............................................................................35
Structure location and surface verification ............................................................35
Shimmed surface profile control feasibility ...........................................................40
Summary ............................................................................................................................41
Chapter IV: Results ........................................................................................................................43
Baseline of Process ............................................................................................................44
Ideal State Process .............................................................................................................45
CBA Results.......................................................................................................................50
Structure Location and Surface Verification Results.........................................................51
Shimmed Surface Profile Control Feasibility Results .......................................................54
Summary ............................................................................................................................59
Chapter V: Discussion ...................................................................................................................60
Significance of the New Automated Shimming System Concept .....................................60
Non-Contact Measurement Systems for Structure Location and Surface Verification .....61
7
© 2011 Lockheed Martin Corporation
Release Agent and Shimmed Surface Profile Control .......................................................62
Conclusions ........................................................................................................................62
Recommendations ..............................................................................................................63
References ......................................................................................................................................64
Appendix A: Detailed Release Agent Test Instructions ...............................................................67
Appendix B: Automated Shimming System Design Requirements .............................................70
Appendix C: Supplier Selection....................................................................................................76
Appendix D: Summary of Supplier Responses from RFI Conference .........................................77
Appendix E: Detailed Gage R&R Results ....................................................................................78
Appendix F: OML Control Tool Test Fixture Details ..................................................................81
8
© 2011 Lockheed Martin Corporation
List of Tables
.................................................................................................................................................... Page
Table 1: Summary of deliverables and methods ...........................................................................43
Table 2: Manual vs. automated process span time comparison ....................................................50
Table 3: Summary of automated shimming system CBA ............................................................51
Table 4: Non-contact metrology gage R&R results ......................................................................52
Table 5: Non-contact metrology accuracy test results ..................................................................52
Table 6: Metrology system time test results .................................................................................53
Table 7: Release agent pull test results - Tensile stress at max load ............................................55
Table 8: Cured shim surface profile measurements on Teflon pull test coupons .........................57
Table 9: OML control tool potential material and surface finish cost study summary ................57
9
© 2011 Lockheed Martin Corporation
List of Figures
.................................................................................................................................................... Page
Figure 1: F-35 Forward fuselage understructure and skins ..........................................................10
Figure 2: F-35 Forward fuselage designed-in shim gap ...............................................................11
Figure 3: Forward fuselage shimmed surfaces .............................................................................11
Figure 4: Manual application of liquid shim.................................................................................13
Figure 5: Problems with overpress method of shim application...................................................14
Figure 6: Accuracy and gage R&R test article .............................................................................36
Figure 7: Nikon Laser Radar MV330 ...........................................................................................37
Figure 8: Hexagon Cognitens WLS400M white light scanner .....................................................38
Figure 9: GOM ATOS Triple Scan ...............................................................................................39
Figure 10: Production forward fuselage used for large-scale time tests .......................................40
Figure 11: Release agent testing setup ..........................................................................................41
Figure 12: Baseline process flow diagram with span times ..........................................................45
Figure 13: Automated system concept layout ...............................................................................46
Figure 14: Automated system process flow diagram with estimated span times .........................49
Figure 15: Surface points collected on forward fuselage for time test .........................................53
Figure 16: Release agent pull test coupons ...................................................................................54
Figure 17: Release agent pull test results ......................................................................................56
Figure 18: OML control tool design .............................................................................................58
10
© 2011 Lockheed Martin Corporation
Chapter I: Introduction
The F-35 Joint Strike Fighter is a fifth generation multi-role fighter jet that is dependent
on stealth technology for mission success. To meet design specifications, its manufacturing
processes require precision control of the outer mold line (OML). The F-35 forward fuselage is
produced at Lockheed Martin Aeronautics in Fort Worth, Texas. The design of the forward
fuselage requires a shim gap between the assembled metallic understructure and the mating inner
mold line (IML) machined composite skins. The forward fuselage assembled understructure and
skins are shown in Figure 1. The designed-in shim gap shown in Figure 2 can vary based on the
assembly tolerances of the understructure.
Figure 1. F-35 Forward fuselage understructure and skins
11
© 2011 Lockheed Martin Corporation
Figure 2. F-35 Forward fuselage designed-in shim gap
The current method for shimming the forward fuselage requires the bonding of hard
shims to the flanges around the perimeter of the right-hand and left-hand sides of the structure,
while liquid shim is bonded to the flanges in the middle section shown in Figure 3. The hard
shims are made of composite and are necessary in specific areas for wear and load requirements.
The liquid shim is a Hysol EA9377 product referred to as moldable plastic shim (MPS). Both
the hard and liquid shims are bonded to the assembled forward fuselage understructure thicker
than the profile requirement, and the entire assembly is taken to a large precision milling
machine (PMM) where the surface profile is machined to very tight tolerances to match the
mating skins.
Figure 3. Forward fuselage shimmed surfaces
12
© 2011 Lockheed Martin Corporation
The problem with this shimming process is that it is very time consuming and subject to
quality issues. The liquid shimming process itself can consume over 60 manufacturing hours per
aircraft since it is completely manual. Initially, mechanics applied the liquid shim to the
understructure and manually spread it with Popsicle sticks to cover the surface. This method,
shown on the left side of Figure 4, proved difficult to maintain a constant thickness of cured
shim. The process was messy and required extensive rework in many cases. A new method for
controlling the cured thickness of the MPS, shown on the right side of Figure 4, was
implemented during the F-35 system design and development (SDD) phase. This patented
process uses stereolithography overpresses which utilize standoff nubs to control the cured
thickness of the MPS. In this method, the MPS is applied to the overpress, the overpress is
applied to the structure, and the mechanic secures the overpress to the structure with C-clamps
and cleans up the liquid shim squeeze out. The MPS is allowed to cure for eight hours and the
overpresses are removed. The mechanic then back fills the indentations produced by the
thickness control standoffs with additional liquid shim and allows for another eight hour cure
prior to sending the entire structure to the PMM. Often, after machining the shimmed surfaces,
air gaps are exposed and additional rework is required to fill the voids and hand sand the surfaces
to the correct profile.
13
© 2011 Lockheed Martin Corporation
Figure 4. Manual applications of liquid shim
A. Manual application without using overpresses
B. Manual application using the overpress method
The overpress method of shim application was not designed for F-35 full rate production
(FRP) which has a goal of one aircraft per day. Rate problems with the current overpress method
include:
• The extensive cost and storage for rate quantities of 40 overpresses and 260 C-clamps
per ship set.
• The cost and time to procure replacement overpresses which often break during their
removal from the structure.
14
© 2011 Lockheed Martin Corporation
• The thickness control standoffs, shown in Figure 5, result in a second cure time.
• The MPS surface requires expensive PMM machine time.
• Entrapped air exposed after PMM machining, shown in Figure 5, results in rework
and a third cure time.
• The thick application of MPS and operator dependency results in excessive material
waste.
Figure 5. Problems with overpress method of shim application
This chapter will present the problem statement, objectives, and significance of the study.
Statement of the Problem
The current F-35 forward fuselage shimming method results in excessive span time,
extensive manual labor, extreme material waste, and quality issues which make it impossible to
support a peak production rate of one aircraft a day.
15
© 2011 Lockheed Martin Corporation
Purpose of the Study
The purpose of this study was to develop a concept for an efficient, automated F-35
forward fuselage liquid shimming system and to verify the feasibility of specific components of
the system. The deliverables of this study were to:
1. Establish the inefficiencies in the current shimming process and outline an ideal state
process.
2. Document F-35 automated system and shimming requirements.
3. Identify existing automated technologies related to liquid shim, sealant, or adhesive
dispense and other associated shimming tasks.
4. Identify potential system solutions for incorporation into a specification.
5. Determine the feasibility to use non-contact metrology technology to locate the
structure and validate the surface profile before and after shim installation.
6. Identify various material options and release agents for an OML control tool, and
design and fabricate a single piece sub-scale OML control tool which could later be
used to evaluate the tool’s ability to release from the structure after the shim has
cured, tool locating techniques, and OML control tolerances achievable with no
additional processing of the cured shim.
Automated dispense systems are not a new technology; however, compared to the
automotive industry, the tight tolerances, expensive and delicate parts and assemblies, and lower
manufacturing rates of the aerospace industry require special considerations. The automated
shimming system needs to apply liquid shim as well as aid in OML control processes that must
meet stringent tolerance requirements. This study provides Lockheed Martin Aeronautics the
necessary foundation to verify system feasibility and validate system components in order to
16
© 2011 Lockheed Martin Corporation
begin specification development for the procurement of an automated shim cell for F-35 forward
fuselage OML control.
Assumptions of the Study
This study builds on existing automated dispense and robotic technology; therefore, the
research assumes technology suppliers will work cooperatively with Lockheed Martin
Aeronautics when examining existing technology and proposing a system to meet the
requirements.
Definition of Terms
F-35: The F-35 Lightning II, or the Joint Strike Fighter, is a state-of-the-art fighter jet currently
in low rate production at the Lockheed Martin Aeronautics final assembly plant in Fort Worth,
Texas. This Department of Defense program is aimed at “defining affordable next generation
strike aircraft weapon systems for the Navy, Air Force, Marines, and our allies” (“The F-35,”
n.d., para. 1).
Coordinate Measuring Machine (CMM): The CMM is “a sophisticated measuring instrument
with a flat polished table and a suspended probe that measures parts in three-dimensional space”
(“Basics,” 2011, para. 3).
Gage Repeatability & Reproducibility (R&R): A gage R&R study measures the sources of
variation in a measurement and determines if the gage is “acceptable for its intended use” (Sloop,
2009, p. 44).
17
© 2011 Lockheed Martin Corporation
Inner mold line (IML): For the F-35, IML refers to inner surfaces of parts that are measured
and controlled in order to maintain the outer mold line surfaces.
Metrology: Metrology is “the science of measurement” (“Metrology,” n.d., para. 1).
Outer mold line (OML): For the F-35, the OML refers to the outer surface of the aircraft or the
outer surface of a part or assembly in a specific portion of the fabrication process.
Overpress: The overpresses designed to aid in manual liquid shim application for the F-35
forward fuselage have a surface that mimics the profile of the forward structure (Hestness, 2006).
That surface contains thickness control standoff nubs to provide a constant thickness of cured
shim to be machined. The overpress is removed after the shim has cured and before it is
machined.
Request for information (RFI): The RFI is a process used to gather general information about
the capabilities of potential suppliers, future steps that need to occur, product offerings, and
pricing options. The data is used for further product definition and comparative purposes
(“Request,” n.d.).
Shim: A shim is a material that is used to fill space between things (“Shim,” n.d.).
18
© 2011 Lockheed Martin Corporation
Structured improvement activity (SIA): An SIA is tool used by Lockheed Martin to determine
the problems with or inefficiencies in a design or process and document solutions for it. The SIA
is typically a multi-day meeting involving all stakeholders and utilizing other lean six sigma
tools.
System design and development (SDD) phase: During the SDD phase of the F-35, the entire
aircraft system, including the manufacturing process, is developed and tested (“F-35," n.d.).
Limitations of the Study
This study is limited to the investigation of existing technologies. This research built on
those technologies to meet the requirements of the F-35 forward fuselage liquid shimming
process. Budget and time restrictions limit the ability to develop something completely
revolutionary.
Methodology
The remainder of this paper will review previous research related to aerospace fabrication
and assembly challenges as well as present studies supporting the feasibility of addressing these
challenges. This paper summarizes the methods used by this research to create a concept for an
automated liquid shimming system to address the current manual shimming challenges used on
the F-35 forward fuselage. This research completed tasks to address the deliverables of this
project, including automated system concept development, non-contact metrology testing,
release agent pull testing, and OML control tool design. The results and analysis completed by
this research are presented in the following sections. The paper discusses the significance of the
19
© 2011 Lockheed Martin Corporation
new shim cell concept and the results of the component feasibility testing as well as suggests
opportunities for further development.
20
© 2011 Lockheed Martin Corporation
Chapter II: Literature Review
The focus of this literature review is to summarize topic areas related to aerospace
fabrication and assembly challenges, as well as to present studies supporting the feasibility of
addressing these challenges. The review describes what shimming is and the purpose of
shimming, benefits of automation, various uses for automation in industry, types of metrology,
and studies related to uses of metrology in coordination with automation.
Shimming in the Aerospace Industry
Shimming in the aerospace industry is very common. Components and assemblies are
typically built to much tighter tolerances than other industries because of the functions of the
manufactured parts. Lockheed Martin design engineer, Dan Heap, describes that fabrication of
parts with certain materials, such as composites, also results in unknown surfaces and tolerance
stack-ups that require shims to be designed in to the components. Shims are also used to keep
finished assembly weight to a minimum. The following sections will discuss what shims are and
why they are used.
Shim description
A shim is a material that is used to fill space between things (“Shim,” n.d.). Shims can
be made from a variety of different materials depending on the application. In the aerospace or
automotive industries, shim materials can include metallic laminated shim stock, nonmetallic
laminated shim stock, metallic solid shim stock, composite solid shim stock, and moldable
plastic shim (MPS) (Graydon, 2006). Solid shims are typically bonded to a surface with an
21
© 2011 Lockheed Martin Corporation
adhesive, while MPS is a liquid shim that is directly applied to the surface where it cures and
bonds. Shims can either be machined to the proper dimensions prior to bond, or they can be
bonded to the structure and either molded or machined to the correct profile. The surface must
be prepared prior to bond, and shims are usually located with some sort of hard tooling or shop
aids (Graydon, 2006).
Purpose of shims
Shims fulfill many purposes in manufactured products. Shims carry loads, adjust
surfaces to decrease mismatch, provide wear resistance, or ensure a proper fit between mating
parts or adjoining surfaces (“Shim,” n.d.). In aerospace, shims are typically designed into the
manufacturing plan to account for a tolerance stack up in final assembly. A tolerance stack up
analysis can be completed to determine the tolerance value of the whole assembly or a specific
gap of the assembly when the tolerances of each part in the assembly are known. According to
Foster (1994), a tolerance is the total amount that a specific dimension may vary. The tolerance
is the difference between the maximum and minimum dimensions that the part can be accepted.
Every manufactured part has a tolerance associated with it. Those parts outside the tolerance are
usually discarded. Tighter tolerances are more difficult to meet, very expensive, and increase the
number of failed parts. Shims allow for more lenient tolerances. It would be impossible to
produce every part perfectly; no two parts are the same (Morey, 2011). Shims can be employed
to overcome manufacturing uncertainty.
Utilizing proper geometric dimensioning and tolerancing is essential for cost-effective
manufacturing and dependable metrology, assembly, and part operation (Tandler, 2010). If the
final assembled part has very loose tolerances, shims may not be needed to account for the
22
© 2011 Lockheed Martin Corporation
individual part variation or the assembly variation. For instance, the assembly of a bookshelf
does not require tight tolerances. The bookshelf only needs to be somewhat level to the eye, but
it would still perform the same function if there were small gaps between the shelves and the
structure walls or even if the shelves were tilted at a small angle. According to Lockheed Martin
applications engineer, Jeff Langevin, aircraft assembly requires extremely tight tolerances, to the
order of thousandths of an inch; therefore, shims must be used to fill gaps resulting from
manufacturing and assembly tolerances.
Industrial Automation Considerations
Automating a process can significantly reduce the amount of time that process takes and
the amount of inconsistency associated with manually performing that process (Hensley, 2008).
Automation is not right for everything; the application must be carefully considered in order to
determine if automating the process is cost-effective. Automation must provide cost savings to
justify the capital investment needed to develop and implement the process. The following
sections will discuss what automation is as well as the benefits and uses for robotic automation.
Automation descriptions
Industry is using more computer-based automation due to the desire for increased
productivity and the delivery of quality products (Fu, Gonzalez, & Lee, 1987). Many automated
manufacturing tasks are completed by hard automation systems designed to perform
predetermined functions. The inflexibility and relatively high cost of these machines have led to
a lot of interest in the use of robots, which are a type of automation capable of performing
23
© 2011 Lockheed Martin Corporation
various manufacturing functions in a more flexible working environment and at lower production
costs.
“A robot is a reprogrammable general-purpose manipulator with external sensors that can
perform various assembly tasks” (Fu et al., 1987, p. 1). The key words are reprogrammable and
variety. A robot is a type of automation, but hard automation is not a type of robot because it is
built for a single purpose and rarely adaptable for another job.
An industrial robot is a general-purpose, computer-controlled manipulator consisting of
several rigid links connected in series by revolute or prismatic joints. One end of the
chain is attached to a supporting base, while the other end is free and equipped with a tool
to manipulate objects or perform assembly tasks (Fu et al., 1987, p. 1).
The benefits of robotic automation
Typically, the aerospace industry has steered clear of robots. Before an aircraft part
enters an automated process, it normally requires a lot of manual work. Many automated
machines for the fabrication and assembly of aircraft components are specifically designed for a
single function (Webb, Eastwood, Jayaweera, & Chen, 2005). Unlike the automotive industry,
military fighter aircraft are produced at much lower rates, and tolerance requirements are often
tighter than robotic processes can control. However, for specific process, robots may provide a
solution that is more flexible than a dedicated machine. According to Teresko (2008), robots can
be programmed to perform a variety of tasks, and they are repeatable. Robots are also good at
performing tasks that are redundant or that exist in environments that are dangerous for humans.
The automotive industry has gained a lot of benefits from the integration of robots into various
24
© 2011 Lockheed Martin Corporation
manufacturing processes (Teresko, 2008). Robotic automation can help reduce direct labor
costs, free up skilled labor, and increase quality (Hensley, 2008).
Robotic automation for specific manufacturing processes can be economical. The typical
six-axis robot is more affordable than and can be just as effective as a custom-built machine
(Hensley, 2008). Robotic automation is also much simpler to deploy than setting up customized
machines. Robots are flexible for various applications and various work envelopes. In addition,
robots can endure repetitive, time consuming, and tedious tasks. Allowing robots to do these
types of tasks frees up operators to perform other tasks, allowing productivity to increase without
adding additional labor. Robotic automation is not just appropriate for high volumes. With the
use of special software, robots can be programmed offline to avoid expensive setup time in order
to be cost effective for low-volume production (Brown, 2009). Finally, automation can improve
quality metrics (Hensley, 2008). Process flaws are exposed much more quickly in an automated
process because machines do exactly the same thing every time, unlike humans.
Uses of robots
Industrial robots are widely used in manufacturing and assembly tasks including material
handling, spot/arc welding, parts assembly, paint spraying, loading and unloading numerically
controlled machines, space and undersea exploration, prosthetic arm research, and in handling
hazardous materials (Fu et al., 1987). According to Paul Graham, one of the managers at the
Arlington, TX General Motors manufacturing plant, the auto industry employs robots to
assemble major auto body parts, perform welding tasks, apply adhesives and sealants, install
windshields and other components, and check parts. (P. Graham, personal communication, June
27, 2011). These applications can be used in aircraft production with minor adjustments.
25
© 2011 Lockheed Martin Corporation
Other industries use robots for packaging and palletizing (Langnau, 2005). Robotic
palletizing is on the rise. Palletizers are large, hard to maintain, expensive, and take up a lot of
floor space. Using a robot with custom end effectors to palletize allows for much more delicate
handling of materials than palletizers and much more efficiency than humans. Robots also allow
for flexibility and minimized changeover and setup time for multiple stacking patterns. Robotic
palletizing requires less area and power consumption and can handle multiple products
simultaneously.
Bombardier Aerospace is gearing up to use robots to help assemble the cockpit and
fuselage of its CSeries aircraft (“Bombardier,” 2011). Because this aircraft is larger than any
Bombardier has ever built, the previous manual assembly methods would be ergonomically
challenging. Using a robot to join the fuselage sections will eliminate many hours of manual
labor including assembly of scaffolding to reach the top of the plane.
Metrology Enhances Automation Capabilities
Various kinds of measurement instruments exist to ensure manufactured parts comply
with engineering design. The correct measurement instrument must be selected for the
appropriate application. Non-contact metrology systems are being used more and more in the
aerospace industry for many inspection applications, especially as tolerances tighten and rate
increases. Research shows that these systems can also be used to enhance fabrication and
assembly processes as well (Jamshidi et al., 2010; Jayaweera & Webb, 2007; Noruk, 2011;
Webb et al., 2005). The following sections will discuss various types of metrology and how it
has been used in coordination with automated systems to improve the system capabilities for
assembly processes.
26
© 2011 Lockheed Martin Corporation
Types of metrology
Metrology is “the science of measurement” (“Metrology,” n.d., para. 1). Applied
metrology has to do with the application of measurement science to manufacturing processes to
make sure the appropriate measurement instruments are used in order to ensure the accuracy of
the measurements. There are various types of metrology used in the aerospace industry.
Coordinate measuring machines (CMMs), which can take up a lot of floor space and can
be very expensive, were developed over 60 years ago in order to measure precision military
components (O’Rourke, 2011). The aerospace industry considers these types of touch probe
inspections very accurate; touch probe and manual gauge inspections are used as the baseline
process in most cases. However, the need for inspections with better resolution, faster processes,
and reduced capital costs is always increasing, especially as parts become more complex and
difficult to inspect (O’Rourke, 2011). Because of this, many non-contact metrology systems
have been developed. One example is a laser scanner. Laser scanning allows three-dimensional
data to be collected in order to create a computer aided design (CAD) model of the as-built part
so that it can be compared to the nominal CAD model of the part (O’Rourke, 2011). By using a
laser line to scan the part surface, thousands or even millions of data points can be quickly
collected and processed to create the part geometry.
Laser trackers are also very popular in the aerospace industry (Morey, 2011). A laser
beam produced by the tracker reflects off a spherical mounted retroreflector (SMR). Distance is
calculated by measuring two angles and the length to the SMR. Although most laser trackers are
manually operated, there is a continuing trend toward integrating them into automated systems as
control sensors.
27
© 2011 Lockheed Martin Corporation
It is challenging and sometimes impossible with touch probes to measure free-form
surfaces that require a large density of points. Unlike laser trackers, laser radars do not require a
reflector target (Morey, 2011). Laser radars are easily automated because they do not require an
operator to touch the part, and hundreds or thousands of points can be collected per second.
Another system that is useful for free-form part measurement is structured white or blue
light systems (Morey, 2011). These systems use a light source and imaging cameras to calculate
locations in space for various surfaces or part features. With all of these alternate metrology
options, choosing with right one for the application can be a challenge. There are some
restrictions with non-contact measurement devices. It is difficult to collect data on shiny or
translucent surfaces, and large parts require data to be digitally stitched together. Part vibration
during measurement is also a concern.
Metrology and automation for assembly processes
Using robotics to fabricate and assemble large structures that have tight tolerances has
been limited by size and accuracy requirements of the components involved. Variation is a basic
component of the manufacturing process of these structures because of inconsistencies in
materials, tools, factory environments, and human intervention (Jamshidi, Kayani, Iravani,
Maropoulos, & Summers, 2010). Because of the tight tolerances required to fabricate and
assemble these components, simple robotic approaches cannot be used due to the inherent
dimensional variability in the parts. Several case-studies and tests have been performed to help
solve this problem by using non-contact metrology systems in coordination with automated
processes to measure part deformation and misalignment in real time (Jamshidi et al., 2010;
Jayaweera & Webb, 2007; Noruk, 2011; Webb et al., 2005). “Metrology is becoming a major
28
© 2011 Lockheed Martin Corporation
contributor to being able to predict, in real time, the automated assembly problems related to the
dimensional variation of parts and assemblies” (Jamshidi et al., 2010, p. 25).
A robot with vision capabilities has the ability to sense specific environmental factors and
respond to those factors appropriately (Fu et al., 1987). The use of vision is motivated by the
continuing need to meet more difficult manufacturing challenges with the use of inexpensive and
less specialized equipment. Vision uses pattern recognition of video signals to find information,
compare that information to a learned image, and then intelligently interpret that information to
perform appropriate actions (Fu et al., 1987; Ardayfio, 1987). Robot vision systems provide the
most basic automated real-time inspection systems; however, they only provide a means for the
robot to respond to programmed and predicted conditions. A vision system does not generate
any new data like other metrology systems.
Laser vision sensing can play an important role in automated systems like the automated
welding process (Noruk, 2011). One way to achieve a flexible, adaptive welding system and
avoid excessive variability in the parts and fixturing is to use laser vision sensors for joint
finding, joint tracking, and automated weld inspection. Laser vision allows an automated
welding system to begin welding if a joint is in tolerance or to prevent welding if it is out of
tolerance. Laser vision sensing can also compensate for a joint that is within tolerance but still
has too much variability for automated welding without vision.
Laser vision has also been investigated by Jayaweera and Webb (2007) for automated
aircraft assembly. For a manual assembly process, individual parts are located with setup holes
that are machined to a very tight tolerance. In order to be able to use an automated system to
assemble aircraft parts to the same tolerances as a tool-assisted manual process, a metrology
system must be used to locate the individual parts throughout the assembly process (Jayaweera &
29
© 2011 Lockheed Martin Corporation
Webb, 2007). A side benefit of laser vision is that it provides a quality assurance check
concurrent with assembly. Often, during part manufacturing and assembly, the structures are
deformed from their original machined shape. Because the part geometry and dimensions
change, the metrology system aids in the alignment process by providing feedback to the
automated system about the as-is part geometry and hole location. If installation cannot be
accomplished within tolerances, the part can be rejected automatically. Jayaweera and Webb
(2007) found that automated assembly could be accomplished within the necessary production
tolerances by using a robot in coordination with a laser vision system.
Jamshidi et al. (2010) performed a case study on an aircraft wing to evaluate the adaptive
control enhancement of a robotic system utilizing metrology systems which provided inputs to
the robot controller to compensate for positioning errors. The measurement and scanning data
was used to guide the robot for manufacturing and assembly processes. The researchers used
three different measurement technologies, including a laser tracker, a laser radar, and a handheld
scanner with a tracking camera. The laser tracker was used to evaluate the fixturing and the
effect of surrounding vibration. Both the laser tracker and the laser radar were using during the
assembly process for inspection purposes. The scanner was used to acquire data for shimmed
surfaces. The researchers found that in some cases, the robot positioning could be corrected
using the adaptive control system; however, the system could not account for deviations in
assembly for loading parts. The assembly tolerance stack-ups made it too difficult to properly
load a part. Jamshidi et al. (2010) determined that for automation to work, metrology systems
should be an integral part of the assembly process. This compensates for assembly discrepancies
and required production assembly tolerances, not just the part positioning process.
30
© 2011 Lockheed Martin Corporation
Webb et al. (2005) developed a flexible robotic rapid assembly cell that was capable of
carrying out several different assembly processes on aero-structure sub-assemblies. Whereas
automotive typically has a robot dedicated to each operation as the structure moves along a flow
line, these researchers used a single robot to reduce the cost of the cell. The conventional
manner to perform the assembly tasks, which utilizes a complex fixture and pre-defined robot
programs, would not be able to achieve the required accuracy and repeatability needed for
aerospace components. The researchers developed a control system that used a CAD model of
the assembly to provide an approximate representation. During the assembly process, several
non-contact metrology systems scan the structure to create an as-is model of the components as
operations are completed and prior to the next operation. By doing this, the robot knows exactly
what the assembled structure looks like at that point in time. Because the structure deforms after
certain assembly operations, the robot has no other way to accurately know where to perform the
next operation unless it has the metrology system telling it where to go. This successful robot
cell shows the potential feasibility of combining non-contact metrology and a cell control system
to assemble structures with tight tolerances and dimensional uncertainty.
Conclusion
While this literature review has discussed several areas related to aerospace fabrication
and assembly challenges, there is still much work to be done to fully address issues with creating
such specialized, low rate parts and assemblies. As aerospace technology complexity increases,
so will the manufacturing difficulties associated with producing these complex engineered parts
and assemblies. This research project was completed to specifically address the production
challenges associated with a manual liquid shimming process used for the fabrication of the F-35
31
© 2011 Lockheed Martin Corporation
forward fuselage. Based on the research completed, technology does exist to potentially meet
the challenges associated with aerospace manufacturing, but specialized systems must be
developed to address each unique challenge. This paper presents a concept solution to the span,
labor, waste, and quality issues associated with the current manual F-35 forward fuselage
shimming method. The solution consists of an automated shimming system which incorporates
robotic automation, 3D metrology technology, and special tooling.
32
© 2011 Lockheed Martin Corporation
Chapter III: Shimming Methodology
The current F-35 forward fuselage shimming method results in excessive span time,
extensive manual labor, extreme material waste, and quality issues which make it impossible to
support a peak production rate of one aircraft a day. The purpose of this study was to develop a
concept for an efficient, automated F-35 forward fuselage liquid shimming system and to verify
the feasibility of specific components of the system. The concept included the new process flow
and equipment requirements for the shim cell. This study was significant because it provides
Lockheed Martin Aeronautics the necessary foundation to verify system feasibility and validate
system components in order to begin specification development for the procurement of an
automated shim cell for F-35 forward fuselage OML control.
Concept Development
The first part of the purpose of this project was to create a concept for an automated
shimming system. The deliverables for this task included:
1. Establish the inefficiencies in the current shimming process and outline an ideal state
process.
2. Document F-35 automated system and shimming requirements.
3. Identify existing automated technologies related to liquid shim, sealant, or adhesive
dispense and other associated tasks.
4. Identify potential system solutions for incorporation into a specification.
The following sections will discuss the process taken to achieve these deliverables.
33
© 2011 Lockheed Martin Corporation
Establish a development team
To begin the process, a development team was constructed, and a re-occurring weekly
meeting was setup. The purpose of the team was to gain a clear understanding of the
requirements for a production-ready shimming system, develop a shim cell concept for
incorporation into a future specification, and complete a cost benefit analysis (CBA) for capital
justification. Present in these meetings were representatives from all stakeholders, including F-
35 forward fuselage manufacturing engineering, industrial engineering, facilities, forward
fuselage production, forward fuselage design engineering, and manufacturing technology.
Baseline the process
In order to accomplish the goals established by this research project, several tasks were
completed to compare the old manual processes to the concept for an automated process. First,
this research work baselined the current manual process. A structured improvement activity
(SIA) was held to establish the inefficiencies in the current process and outline ideas for an ideal
state process. This research documented a detailed flow of the manual process and performed
time studies which included observing the current process and gathering historical span and labor
data from previously completed F-35 aircrafts. This research also completed a risk analysis for
the development of the new process and built a document summarizing the shimming
requirements and the production needs.
Investigate existing technologies in the industry
As a part of this project, an industry investigation was completed to understand and
evaluate existing automated technologies related to liquid shim, sealant, or adhesive dispense as
34
© 2011 Lockheed Martin Corporation
well as additional associated shimming tasks. Potential system suppliers, integrators, and
industry partners were contacted, and information was requested to be provided to Lockheed
Martin regarding any related experience with designing, integrating, or using similar automated
equipment. The documented industry information was used to determine relevant suppliers and
integrators to invite to a request for information (RFI) conference. The RFI conference was held
with these suppliers to educate them on Lockheed’s current shimming process and its associated
challenges and to describe Lockheed’s requirements for an automated shimming process.
Conference attendees were asked to propose their solution to an automated shimming system.
Potential system solutions and key findings were identified by this research project as a result of
the RFI for incorporation into a future specification.
Complete a CBA
Baseline process data, documented needs and requirements, and RFI responses were used
by this research to create a concept for the new automated process. The concept was compared
to the baseline process to complete a CBA to calculate the hours per unit (HPU) savings and to
calculate a return multiple (RM), which is equal to the total savings divided by the total cost. All
costs, including capital investment, labor, material, and development costs were considered for
the new process. The cost difference between the baseline process and the new process resulted
in the savings which was extrapolated over the documented F-35 aircraft delivery schedule. The
CBA results help justify a need to change the current manual shimming process and integrate the
new automated system.
35
© 2011 Lockheed Martin Corporation
Verify System Component Feasibility
The second part of the purpose of this project was to verify the feasibility of specific
components of the automated shimming system. The deliverables for this task included:
1. Determine the feasibility to use non-contact metrology technology to locate the
structure and validate the surface profile before and after shim installation.
2. Identify various material options and release agents for an OML control tool, and
design and fabricate a single piece sub-scale OML control tool which could later be
used to evaluate the tool’s ability to release from the structure after the shim has
cured, tool locating techniques, and OML control tolerances achievable with no
additional processing of the cured shim.
The following sections will discuss the process taken to achieve these deliverables.
Structure location and surface verification
Testing was performed as part of this study to determine the feasibility to use non-contact
metrology to locate the structure within the shim cell and validate the surface profile before and
after shim installation. To do this, several studies were performed on the test article shown in
Figure 6 to measure accuracy and gage repeatability and reproducibility (R&R) for laser radar,
white light, and blue light non-contact metrology systems. The test article was an aluminum
plate with a contoured primed surface, three 0.5” tooling spheres, and surface points on 1” grid.
Surface profile measurements were collected with each measurement system, including a
baseline CMM measurement, and the data was analyzed using SPC XL software and an ANOVA
analysis to determine if the non-contact metrologies can meet the tolerance and R&R
36
© 2011 Lockheed Martin Corporation
requirements needed for the automated system to perform structure location and surface
verification.
Figure 6. Accuracy and gage R&R test article
This research selected vendors to test each type of metrology system. The tests were a
collaborative effort between the suppliers and Lockheed Martin. For each type of metrology
system, three operators collected the surface profile points multiple times. The following
procedure was used to gather data for the accuracy and gage R&R tests:
1. Measure locations of the three tooling spheres.
2. Best fit to the tool.
3. Measure 21 surface points.
4. Provide an Excel output of X, Y, Z surface points.
5. Change operator and repeat the data collection process until all data has been collected.
The first supplier to perform the tests was Nikon Metrology with their Laser Radar
MV330 shown in Figure 7. This piece of metrology is a frequency modulated IR laser radar that
provides a non-contact measurement. Two angles (elevation and azimuth) are measured from a
37
© 2011 Lockheed Martin Corporation
mirror pointing system. The range is measured by laser radar. The 3D Cartesian coordinates are
calculated by a simple mathematical transformation of the measured spherical coordinates.
Figure 7. Nikon Laser Radar MV330
The second supplier to perform gage R&R and accuracy tests was Hexagon Metrology
with their Cognitens WLS400M white light scanner shown in Figure 8. The sensor projects a
random burst pattern on an object and triggers a simultaneous capture of area of interest by its
cameras. The images are correlated using proprietary algorithms to create a 3D point cloud
representation of area. The system has a fast acquisition time that allows for on-airplane work
and hand-held operation.
38
© 2011 Lockheed Martin Corporation
Figure 8. Hexagon Cognitens WLS400M white light scanner
The third supplier to perform gage testing was Shape Fidelity. This supplier used a GOM
product called the ATOS Triple Scan shown in Figure 9. This system uses blue light to project a
2D fringe pattern on 3D objects. High resolution digital cameras record these distorted images,
and software calculates the distance from the cameras. The triple scan feature allows for better
definition for complex shapes.
39
© 2011 Lockheed Martin Corporation
Figure 9. GOM ATOS Triple Scan
For this research work, data was also collected with each of the three non-contact
metrology systems on an actual production F-35 forward fuselage shown in Figure 10. This data
was used to understand how each system could collect data on a larger scale and how much time
would be required for data collection. The baseline forward fuselage profile data collection
process utilizes a laser tracker which can take over two hours per side to collect data.
40
© 2011 Lockheed Martin Corporation
Figure 10. Production forward fuselage used for large-scale time tests
Shimmed surface profile control feasibility
Pull tests were completed for this research to identify various material options and release
agents for an OML control tool. Composite, aluminum with a machined finish, and aluminum
with a polished finish coupons were fabricated to simulate potential materials for an OML
control tool. Four release agents, including Zyvax HiVis, McLube 1700R, Teflon tape, and
Zyvax Nano Release were applied to each type of coupon, and a thin layer of liquid shim was
applied between the test coupon and a primed aluminum plate to simulate the forward fuselage
understructure. After the coupons cured for at least eight hours, pull test data was collected with
an Instron machine to determine the force required to release the material from the cured shim.
The pull tests were repeated three times in order to verify results. Detailed test instructions are
described in Appendix A. Figure 11 shows the test setup.
41
© 2011 Lockheed Martin Corporation
Figure 11. Release agent testing setup
As part of this project, a sub-scale OML control test tool for the control of the cured shim
profile was designed and fabricated in coordination with a supplier. The test tool incorporates
two alternate methods for locating the tool to the correct OML position to produce the desired
cured shim profile. This sub-scale tool will be tested in the future to determine if the OML
profile of the shimmed surface mating with the IML profile of the composite skin can be
controlled with a tool without any machining or post processing of the cured shim.
Summary
This research has been carried out to solve the existing problems with the manual
shimming process for the F-35 forward fuselage. A team was assembled to gather requirements
for a production-ready automated shimming system, develop a shim cell concept, and complete a
CBA to justify the need for an automated system. This research work completed gage R&R and
accuracy tests to validate if non-contact metrology systems could be used in the shimming
system to meet requirements for structure location and surface profile verification. Tests were
performed as a part of this study to identify various material options and release agents for an
42
© 2011 Lockheed Martin Corporation
OML control tool, and a sub-scale OML control test tool was designed and fabricated to test the
concept at a later date. The methods used and tests performed in this study provided Lockheed
Martin Aeronautics the necessary foundation and a clear direction to begin specification
development for the procurement of an automated shim cell for F-35 forward fuselage OML
control.
43
© 2011 Lockheed Martin Corporation
Chapter IV: Results
Research and current applications show that technology exists to potentially meet the
challenges associated with aerospace manufacturing, but specialized systems must be developed
to address each unique challenge. The current F-35 forward fuselage shimming method does not
support the peak production rate, so the purpose of this study was to develop a concept for an
efficient, automated F-35 forward fuselage liquid shimming system. The methods used to
accomplish each of the deliverables of this study are discussed in Table 1.
Table 1. Summary of deliverables and methods Item # Deliverable Method
1. Document F-35 automated system and shimming requirements.
Created the requirements for a production-ready shimming system shown in Appendix B.
2.
Identify existing automated technologies.
Completed an industry investigation of automation
suppliers and integrators as well as automotive and aerospace partners to understand and evaluate existing automated and dispense technologies that could be used in an automated shimming system. The supplier selection list is shown in Appendix C.
3.
Identify potential system solutions.
Planned and executed an automated shim cell RFI
conference to get potential concept solutions from suppliers. A summary of the supplier solutions is shown in Appendix D.
4.
Establish the inefficiencies in the current shimming process and outline an ideal state process in order to quantify the potential savings of an automated system.
Completed a baseline flow and total span of the
current shimming process based on time studies and historical data.
Developed a final automated system concept flow with estimated span times based on RFI responses.
Completed a CBA to justify the need for an automated shimming system.
44
© 2011 Lockheed Martin Corporation
5. Conduct testing to verify the feasibility of various components of an automated system.
Performed gage R&R and accuracy tests on three non-contact metrology technologies to determine if systems can be used to locate the structure and validate the surface profile before and after shim installation.
Completed OML control tool release agent pull tests.
Managed subcontract with supplier to design and fabricate a sub-scale OML control test tool for future concept testing.
Baseline of Process
Below is a summary of the baseline process and a flow diagram shown in Figure 12:
Hard shims around the perimeter of the structure
o Composite and aluminum
o Necessary for wear and load requirements
Liquid shim in the middle section
o Hysol EA9377 – moldable plastic shim (MPS)
o Two-part epoxy in 6 oz. Semkits
Shim is bonded to the assembled understructure thicker than the profile requirement
Entire profile is precision machined to match the mating skins
Total span time is 174.78 hours
45
© 2011 Lockheed Martin Corporation
Figure 12. Baseline process flow diagram with span times
Ideal State Process
Figure 13 shows a model of the automated concept shim cell layout.
46
© 2011 Lockheed Martin Corporation
Figure 13. Automated system concept layout
The future automated system developed in this project will include automated transfer
from the forward fuselage Machine Tool Transfer Line into the shimming cell. The robot will
complete operations for structure location, pre-shim surface profile measurement, surface
preparation, shim application, OML control tool placement, edge cleanup, OML control tool
removal, and post-shim surface profile measurement. The system will be equipped with safety
features and an enclosed work cell. The proposed detailed flow for the new process is below and
is summarized with estimated span times in Figure 14:
1. Manually apply solid shims and move forward fuselage to Machine Tool Transfer
Line.
2. Safety system is activated on service isle. Area scanner is used to confirm that safety
area is cleared.
3. Bridge is opened allowing loading station to move loading position.
47
© 2011 Lockheed Martin Corporation
4. Loading station moves to loading position.
5. Machine Tool Transfer Line brings pallet with the fuselage and leaves it the loading
station.
6. Loading station moves pallet with forward fuselage into the robot cell and robot cell
door is closed.
7. Bridge is closed and safety system deactivated.
8. Robot picks probe from the tool rack and locates fuselage position measuring position
of the tooling spheres on the fixture.
9. Robot changes end effector to 3D camera system.
10. Robot performs scanning operation for one side of the fuselage.
11. Robot changes end effector to spindle motor.
12. Robot performs surface preparation operations. Buffing wheels and abrasive disks
are changed when usage time expires.
13. Robot changes end effector to the first dispensing unit.
14. Robot performs dispensing operations and changes dispensing unit automatically to
next one when needed.
15. Robot changes end effector to pick up OML control tool and precisely places it to
squeeze out liquid shim to correct profile.
16. Clamps on tooling activate to hold OML control tool in place.
17. Turntable is turned 180 degrees.
18. Robot performs operation phases 8-16 to the other side.
19. Shim cures for 3 hours.
48
© 2011 Lockheed Martin Corporation
20. Robot picks up end effector to finishing knife and performs finishing operations to
the edges of the shimmed surfaces.
21. Turntable is turned 180 degrees.
22. Finishing operations are performed on other side.
23. Shim cures for remaining 5 hours.
24. Robot removes OML control tool.
25. Turntable is turned 180 degrees
26. Robot removes OML control tool on other side.
27. Robot changes end effector to 3D camera system.
28. Robot performs scanning operation for one side of the fuselage. Output is the
thickness of the shim.
29. Turntable is turned 180 degrees.
30. Robot performs scanning operation for other side of the fuselage. Output is the
thickness of the shim.
31. Fuselage is transferred back to Machine Tool Transfer Line.
32. Fuselage moves to precision milling machine to complete machining of hard shims
and drilling operations.
49
© 2011 Lockheed Martin Corporation
Figure 14. Automated system process flow diagram with estimated span times
Table 2 shows a manual process vs. automated process comparison of the span times
associated with the steps necessary to complete shimming operations on the forward fuselage.
50
© 2011 Lockheed Martin Corporation
Table 2. Manual vs. automated process span time comparison Process Step Manual Process Time (Hrs.) Automated Process Time (Hrs.)
Apply hard shims
Use of metrology systems
Complete surface preparation
Apply liquid shim (including cured shim profile/edge control) Cure Repairs PMM machining
34
9.68
3.4
16.9
24
6.8
80
34
1.34
0.5
5.32
8
N/A
76.5
Total span time
% Reduction
174.78
--
125.74
28.1%
CBA Results
As a part of this project, a cost benefit analysis was completed to justify the need for an
automated shimming system. The concept developed by this research project was compared to
the baseline process to calculate the hours per unit (HPU) savings and a return multiple (RM),
which is equal to the total savings divided by the total cost to implement the new system. All
costs, including capital investment, labor, material, and development costs were considered for
the new process. The return multiple for implementing an automated shimming system in 2013
in place of the current manual shimming process is 15.3 with a payback period in 2016. A
summary of the CBA is shown in Table 3.
51
© 2011 Lockheed Martin Corporation
Table 3. Summary of automated shimming system CBA Savings Category F-35 CTOL F-35 STOVL F-35 CV Average
Current HPU (Hrs.) Target HPU (Hrs.)
263.36
199.66
301.36
231.66
307.36
243.66
290.69
224.99
Total HPU savings
per aircraft (Hrs.)
% HPU reduction
per aircraft
63.7
24.2%
69.7
23.1%
63.7
20.7%
65.7
22.7%
Return multiple
Payback period
(year)
--
--
--
--
--
--
Total
15.3
2016
Structure Location and Surface Verification Results
Table 4 shows a summary of the gage R&R results for the three types of non-contact
metrology under evaluation. In order to meet production requirements, the metrology equipment
must have a precision to tolerance ratio of 30% or less. Smaller percentages are better. The goal
is to have a gage R&R of 10%, but up to 30% is acceptable. Detailed test results are shown in
Appendix E.
52
© 2011 Lockheed Martin Corporation
Table 4. Non-contact metrology gage R&R results Metrology System Precision To Tolerance Ratio
Nikon Laser Radar
Cognitens WLS400M
ATOS Triple Scan
55.08%
16.29%
6.45%
Table 5 shows a summary of the accuracy test results for the three types of metrology
under evaluation. In order to be acceptable for production tolerances, the measurement accuracy
must be 0.002” or less.
Table 5. Non-contact metrology accuracy test results Metrology System Measurement Accuracy
Nikon Laser Radar
Cognitens WLS400M
ATOS Triple Scan
0.004”
0.0006”
0.0003”
Based on the test results shown in Tables 4 and 5, both the Cognitens WLS400M and the
ATOS Triple Scan systems are capable of meeting the profile measurement tolerances and the
repeatability and reproducibility requirements for the forward fuselage. Because the ATOS
Triple Scan provided the best results in both categories, this is the metrology system that this
research has selected for the final automated system concept described in this paper.
As a part of this study, each vendor was asked to prove that their system could perform
the profile measurements on a production forward fuselage and document how the system
53
© 2011 Lockheed Martin Corporation
collected the data on this larger scale. During this test, time data was collected with each
metrology system.
The Laser Radar was programmed to measure each point prior to the inspection. All of
the data was gathered in a single setup, so no data stitching was required. For the Cognitens
WLS400M and the ATOS Triple Scan systems, photogrammetry was used prior to the 3D light
scan. The view range of the scanners is limited; therefore, in order to capture large volumes of
data, a stitching process must be used. All three systems were able to capture the necessary data.
The surface points collected for the time test are shown in Figure 15. The results of the
time study are shown in Table 6. All of the metrology systems show a significant time reduction
in data collection compared to the baseline process.
Figure 15. Surface points collected on forward fuselage for time test
Table 6. Metrology system time test results Metrology System Time To Collect Data (Hrs.) % Reduction
Baseline: Laser Tracker
Nikon Laser Radar
Cognitens WLS400M
ATOS Triple Scan
2.42
0.83
0.67
0.75
--
65.7%
72.3%
69.0%
54
© 2011 Lockheed Martin Corporation
Shimmed Surface Profile Control Feasibility Results
Pull tests were completed to identify various material options and release agents for an
OML control tool. Test coupons are shown in Figure 16, and results are shown in Table 7 and
Figure 17.
Figure 16. Release agent pull test coupons
55
© 2011 Lockheed Martin Corporation
Table 7. Release agent pull test results – Tensile stress at max load Release Agent Coupon Material Trial #1 (psi) Trial #2 (psi) Trial #3 (psi)
Nano
Nano
Nano
Teflon
Composite
Machined Aluminum
Polished Aluminum
Composite
2208.77
1194.27
214.97
29.92
1940.79
1476.61
154.48
23.01
373.28
215.28
265.80
36.88
Teflon
Teflon
Machined Aluminum
Polished Aluminum
58.95
N/A*
23.52
31.22
24.86
19.61
1700R
1700R
1700R
Hi Vis
Hi Vis
Composite
Machined Aluminum
Polished Aluminum
Composite
Machined Aluminum
13.98
57.50
57.27
204.13
146.24
73.16
99.35
77.42
249.33
261.19
79.36
97.21
82.89
125.94
231.43
Hi Vis Polished Aluminum 88.00 60.40 148.39
*Not measured because test coupon separated from aluminum bond plate prior to insertion in Instron machine
56
© 2011 Lockheed Martin Corporation
Figure 17. Release agent pull test results
Based on the pull test results, this research determined that Teflon was the best and most
reliable release agent for the OML control tool. The main purpose of the release agent testing
was to determine the best release agent to use in conjunction with the OML control tool. No
release force data was known prior to testing; however, the bonded shim material is rated for
thousands of pounds, so the release forces were expected to be much less once a release agent
was applied. The Nano release and Hi Vis release forces were unacceptable. Teflon provided
the lowest release forces. Surface profile was measured with a profilometer on the Teflon coated
coupons, and the data is shown in Table 8.
57
© 2011 Lockheed Martin Corporation
Table 8. Cured shim surface profile measurements on Teflon pull test coupons Coupon Material Trial #1 (Ra) Trial #2 (Ra) Trial #3 (Ra)
Composite
Machined Aluminum
14
11
26
10
18
13
Polished Aluminum 9 11 7
Based on the results shown in Table 8, this research determined that for the variables
tested, coupon material and surface finish had little effect on the final cured shim surface
roughness. The cured shim surface profile must be 125 Ra or better for production. In the
release agent testing, composite, machined aluminum, and polished aluminum all provided an
extremely good surface finish, therefore all of them were acceptable materials for the OML
control tool. Because of this conclusion, a cost study was performed for this project for the
various material options and surfaces finish combinations. A composite OML control tool would
require an invar cure tool and a trim tool for machining operations, greatly affecting the cost of
the material per square inch. A hand-polished surface more than doubles the cost of aluminum
compared to a machined aluminum surface. The cost summary is shown in Table 9.
Table 9. OML control tool potential material and surface finish cost study summary OML Control Tool Material Cost/in2
Composite
Machined Aluminum (63 Ra)
Polished Aluminum
$304.00
$6.50
$15.50
Based on the cost study and the surface finish results, a machined aluminum material was
selected by this research for the OML control tool.
58
© 2011 Lockheed Martin Corporation
The OML control tool design, shown in Figure 18, incorporates two alternate methods
for locating the tool to the correct position to produce the desired cured shim OML profile. The
first method utilizes the machined hard shim regions at the simulated canopy sill and keel on the
test fixture detailed in Appendix F. The other method utilizes controlled surfaces extending from
the internal tooling. This sub-scale tool will be tested in the future to determine if the OML
profile of the shimmed surface mating with the IML profile of the mating skin can be controlled
with a tool.
Figure 18. OML control tool design
59
© 2011 Lockheed Martin Corporation
Summary
The current manual shimming process is very expensive and time consuming and does
not support a final production rate of one aircraft a day. This research was undertaken to provide
an efficient automated solution to the forward fuselage liquid shimming issues. The results of
the testing conducted for this study are presented in this section.
Based on the literature survey, industry survey results, and based on supplier information,
this research work developed an ideal state process for an automated shimming system. As part
of this study, the baseline process was compared to the automated process to develop the CBA
which shows a 15.3 ratio of total savings to total system implementation costs. Based on the
CBA analysis, an automated liquid shimming system cost is justified.
The metrology gage R&R and accuracy test results completed by this research work
show that the most capable piece of metrology is the GOM ATOS Triple Scan for forward
fuselage structure location and surface verification in the automated shim cell. The testing
performed as part of this research proved that the ATOS scanner can meet the repeatability,
reproducibility, and tolerance requirements for the automated shimming system.
Finally, the release agent tests conducted by this research show that the Teflon has the
lowest release forces and is the best release agent to be used on the OML control tool to control
cured shim liquid profile. Based on the test results, surface finish and OML control tool material
had little effect on the cured shim surface roughness, so the least expensive material under
evaluation, machined aluminum, was chosen for the OML control tool. A sub-scale OML
control tool was designed and fabricated based on the release testing performed in this study. It
is recommended to test the OML control tool at a future date to determine if it can be used to
control the shimmed surface profile within production tolerances.
60
© 2011 Lockheed Martin Corporation
Chapter V: Discussion
In order to develop a concept for an automated F-35 forward fuselage liquid shimming
system that will support a peak production rate of one aircraft a day, this research work targeted
to complete the following important things:
1. Justify a need and a return on investment for an automated shimming system.
2. Determine if efficient non-contact measurement systems could be incorporated into
the system design.
3. Execute testing to develop a design for an OML control tool which can be used to
control cured shim profile.
Automated dispense systems are not a new technology; however, compared to the
automotive industry, the tight tolerances, expensive and delicate parts and assemblies, and lower
manufacturing rates of the aerospace industry require special considerations. The automated
shimming system needs to apply liquid shim as well as aid in OML control processes that must
meet stringent tolerance requirements. This study provided Lockheed Martin Aeronautics the
necessary justification, foundation, and clear direction to begin specification development for the
procurement of an automated shim cell for F-35 forward fuselage OML control.
Significance of the New Automated Shimming System Concept
The concept developed by this research project for an automated shimming system has an
estimated 125.74 span hours, a 28.1% reduction when compared to the current manual process
span. Much of the time is wasted with the current process due to the multiple cure times
associated with filling in voids and completing repairs. The new automated process would
61
© 2011 Lockheed Martin Corporation
provide consistent, repeatable shim application eliminating air voids and provide a method to
control OML profile of the cured shim without machining it, reducing machining time on
expensive precision milling machines. The newly developed concept for an automated system
results in an average of 65.7 labor hour savings per aircraft. The new system also eliminates
quality issues related to shimmed surfaces. Capital costs associated with the automated
shimming system are minimal compared to the return on the investment. This study determined
that the ratio of total system savings to automated system costs is 15.3. The cost benefit analysis
shows that the system will pay for itself in 3 years.
Non-Contact Measurement Systems for Structure Location and Surface Verification
The gage R&R and accuracy tests completed as part of this project for the laser radar,
white light, and blue light systems proved that not all of the systems are repeatable and capable
of locating the forward fuselage structure within the shim cell and verifying the surface profile of
the shimmed surfaces before and after shim application. Only the Cognitens WLS400M and the
ATOS Triple Scan systems are capable of meeting the profile measurement tolerances required
for the forward fuselage and the repeatability and reproducibility requirements. All of the
systems are significantly faster than the current method for surface measurement and capable of
measuring volumes as large as the forward fuselage. Based on the gage R&R and accuracy tests
for the non-contact metrology systems, it is recommended that the GOM ATOS Triple Scan is
the most desirable system for an accurate, efficient, automated measurement system.
62
© 2011 Lockheed Martin Corporation
Release Agent and Shimmed Surface Profile Control
As a part of this study, an OML control tool design was completed based on release tests
which incorporated various release agents on potential OML control tool material and surface
finish combinations. Based on the test results, all the materials tested provided an acceptable
surface finish, so due to the lower costs associated with machined aluminum, the sub-scale OML
control test tool was designed and fabricated with machined aluminum finish. The release agent,
Teflon, provided the lowest release forces and will be used as the release agent for the OML
control tool tests.
Conclusions
The current manual F-35 forward fuselage shimming process is not acceptable for a peak
production rate of one aircraft per day. The purpose of this study was to create a concept for an
automated liquid shimming system which would address the manual process issues of excessive
span, labor, and waste. Based on the literature survey and supplier information this research
determined that the capability exists to automate this very specialized, intricate, tight tolerance
process with the use of non-contact metrology and special tooling designed specifically for this
application.
The CBA completed as a result of this study compared the current manual shimming
process to the automated system concept developed by this research project. The return on
investment calculated provided a return multiple of 15.3, which justifies a need for an automated
shimming system.
Three non-contact measurement systems were tested as a part of this project for
repeatability, reproducibility, and accuracy to determine if they could be incorporated into the
63
© 2011 Lockheed Martin Corporation
system design to locate the forward fuselage structure in the shim cell and measure the shimmed
surfaces before and after shim application. This research found that although all three systems
were significantly faster at data collection than the baseline laser tracker method, only the white
light and blue light systems were able to meet R&R and measurement tolerance requirements.
The automated shimming concept developed by this research provided an OML control
tool to control the cured shim surface profile. This type of special tooling has never been used
for controlling cured shim profile at this large of scale. In order to design an OML control test
tool, this research executed release agent testing to determine the best release agent, surface
finish, and tool material for an OML control tool. The release agent, Teflon, provided the lowest
release forces with no dependency on surface finish or test coupon material.
Recommendations
Based on the conclusions of this study, this research recommends that Lockheed Martin
Aeronautics pursue the procurement of an automated shimming system for the F-35 forward
fuselage. Further testing is recommended using the OML control tool to determine how
repeatable it is at providing a cured shim surface profile within production tolerances. Alternate
non-contact metrology system, such as laser scanners, could also be evaluated as potential
metrology solutions. Overall production system specifications should be developed based on the
concept described in this paper.
64
© 2011 Lockheed Martin Corporation
References
Ardayfio, D. D. (1987). Fundamentals of robotics. New York, NY: Marcel Dekker, Inc.
Basics of the CMM 120: Inspection training. (2011). Retrieved August 5, 2011 from
http://www.toolingu.com/definition-350120-22452-coordinate-measuring-machine.html.
Bombardier steps up to robots. (2011). Retrieved July 8, 2011 from http://www.sme.org/cgi-
bin/getsmepg.pl?/enews/aerodef/2011/jul/article3.htm&&&AERO&&utm_source=aerod
e-newsletter&utm_medium=email&utm_term=article-3&utm_content=in-text-
link&utm_campaign=july-2011.
Brown, A. S. (2009, January). Robot excels at low-volume assembly. Mechanical Engineering,
131(1), 18.
F-35. (n.d.). Retrieved June 26, 2011 from http://www.jsf.mil/f35/.
Foster, L. W. (1994). Geo-metrics III: the application of geometric dimensioning and
tolerancing techniques. Reading, MA: Addison-Wesley Publishing Company, Inc.
Fu, K. S., Gonzalez, R. C., & Lee, C. S. G. (1987). Robotics: control, sensing, vision, and
intelligence. New York, NY: McGraw-Hill Book Company.
Graydon, E. C. Lockheed Martin Corporation, (2006). Application of solid and liquid shim
material in mismatch of structures (LMA-PL001B). Fort Worth, TX: Lockheed Martin.
Hensley, S. (2008, September). Automated from the start. Modern Machine Shop, 81(4), 99-104.
Hestness, M. L. (2006). U.S. Patent No. 7,740,910 B2. Washington, DC: U.S. Patent and
Trademark Office.
65
© 2011 Lockheed Martin Corporation
Jamshidi, J., Kayani, A., Iravani, P., Maropoulos, P. G., & Summers, M. D. (2010).
Manufacturing and assembly automation by integrated metrology systems for aircraft
wing fabrication. Journal of Engineering Manufacture, 224(B1), 25-36.
Jayaweera, N., & Webb, P. (2007). Adaptive robotic assembly of compliant aero-structure
components. Robotics and Computer-integrated Manufacturing, 23(2), 180-194.
Jayaweera, N., & Webb, P. (2007). Automated assembly of fuselage skin panels. Assembly
Automation, 27(4), 343-355.
Langnau, L. (2005, March). Robotic palletizing cuts labor costs. Material Handling
Management, 60(2), 39-41.
Metrology. (n.d.) In Websters online dictionary. Retrieved July 8, 2011 from
http://www.websters-online-dictionary.org/definitions/metrology?cx=partner-pub-
0939450753529744%3Av0qd01-tdlq&cof=FORID%3A9&ie=UTF-
8&q=metrology&sa=Search#922.
Morey, B. (2011, March). Aerospace metrology tools for the working day. Manufacturing
Engineering, 146(3), 53-65.
Noruk, J. (2011). Optimizing shipyard welding with intelligent process controls. Welding
Journal, 90(2), 46-49.
O'Rourke, K. (2011, April). Strength in numbers. Quality, 50(4), 36-38.
Request for Information. (n.d.) In Wikipedia online encyclopedia. Retrieved July 31, 2011 from
http://en.wikipedia.org/wiki/Request_for_information.
Shim. (n.d.). In Websters online dictionary. Retrieved July 7, 2011 from http://www.websters-
online-dictionary.org/definitions/shim?cx=partner-pub-0939450753529744%3Av0qd01-
tdlq&cof=FORID%3A9&ie=UTF-8&q=shim&sa=Search#906.
66
© 2011 Lockheed Martin Corporation
Sloop, R. (2009, September). Understand gage R&R. Quality, 48(9), 44-47.
Tandler, W. (2010, February). Making GD&T work. Quality, 49(2), 18-19.
Teresko, J. (2008, September 1). What happened to the "auto" in automation. Industry Week,
257(9), 22-24.
The F-35 Lightning II. (n.d.). Retrieved June 26, 2011 from http://www.jsf.mil/.
Webb, P., Eastwood, S., Jayaweera, N., & Chen, Y. (2005). Automated aerostructure assembly.
The Industrial Robot, 32(5), 383-387.
67
© 2011 Lockheed Martin Corporation
Appendix A: Detailed Release Agent Test Instructions
Obtain liquid shim and let it warm to room temperature prior to continuing with prep instructions
Test Sample Preparation
• Wipe surface with clean cloth moistened with approved solvent
• Immediately wipe surface dry with approved cloth
• Let surface dry for a minimum of 15 minutes prior to release application
• Apply release agent and allow to dry 15 minutes
• Apply a minimum of 2 additional coats with a minimum 15 dry time between (Teflon
tape requires only one application and no “dry time”)
– Allow minimum 15 minutes after final coat before next operation
– If applying tape, ensure minimal overlap of strips while maintaining full coverage
of test piece
• Write on top of each test piece the material type, release method, and test number
Base Plate Setup
• Obtain primed base plates, cut in 12” x 3” x 0.25” strips
– Should be able to hold minimum of 3 test pieces each
• Prepare primed surface
– Mask any surrounding areas that may require subsequent painting, sealing, or
bonding
– Clean surface
– Scuff sand primer with Scotchbrite to break surface glaze
– Immediately wipe all surfaces with a clean dry cloth and repeat cleaning
68
© 2011 Lockheed Martin Corporation
– Shim should be applied within 4 hours of cleaning and prepping
• Obtain Teflon tape and apply to fixture
– Should cover base plate surface longitudinally .625” in from EOP on each side,
along with strips covering the ½” space between coupons
MPS Application
• Obtain liquid shim (room temp) and fan tip applicator
• Mix liquid shim per manufacturer’s instructions
• Document “Out-Time” and “Mix-Time” in notebook
• Apply liquid shim directly to prepped (primed side) of base plate
• Carefully spread liquid shim with popsicle stick in thin, consistent layer to avoid air
bubbles
Test Sample Application
• Lay 1.5” x 3” coupon directly on liquid shim, released side down, longitudinally aligned
with base plate
• Try to place correctly the first time to eliminate sliding of test piece in MPS
• Place next coupon on base plate approximately 1” from previous coupon
• Press coupons firmly to base plate, ensuring squeeze-out on all sides
• Wipe excess MPS from sides of coupon
• Once all coupons are on base plate, clamp in place with slide-clamps (do NOT use C-
Clamps since the twist and will move coupon)
• Clamp just tight enough to hold coupon in place
• Document time of completion in notebook and on test fixture
69
© 2011 Lockheed Martin Corporation
Cure Time
• Let liquid shim cure 3 hrs, undisturbed, then carefully remove excess squeeze out with a
blade
• Let liquid shim cure an additional 21 hrs, undisturbed
Post Attachment (for connection to Instrom machine)
• Clean and prep top surface of coupon
• Bond post to center of coupon
• Let cure for 24 hrs
Removal of Test Pieces
• Document time in notebook and on test fixture
• Complete pull tests on Instron machine
• Write force required on the back of the coupon
• Document any visual deformations noticed, quality of MPS surface, and visually inspect
release agent on coupon
• Repeat until all coupons are removed
70
© 2011 Lockheed Martin Corporation
Appendix B: Automated Shimming System Design Requirements
Surface Preparation Requirements
• Mask
• Currently, All Surrounding Areas/Edges Must Be Masked, But The Goal Is To
Eliminate The Masking Step By Having A More Controlled Shim Application.
• Clean
• Substrate Must Be Wiped With Clean Wipe Cloth (AMS 3819, Grade A, Class 1,
2, Or 3) Moistened With LM Proprietary General Purpose Solvent.
• Surface Must Be Immediately Wiped Dry Using Clean, Dry Approved Wipe
Cloth.
• Solvent Must Dry For A Minimum Of 15 Minutes Prior To Proceeding With
Additional Operations.
• Scuff
• Surface Must Be Abraded To Break Surface Glaze Using 120 Grit Or Finer
Aluminum Oxide Abrasive (Scotchbrite Or Equivalent) Abrasive.
• Surfaces Must Be Immediately Wiped With A Clean Dry Cloth.
• Clean
• Repeat Cleaning As Stated Above.
• Note: MPS Must Be Applied Within Four Hours Of Surface Preparation.
71
© 2011 Lockheed Martin Corporation
Shimming Requirements
• Material
• Required Shim Material Is Hysol EA9377 Moldable Plastic Shim (MPS) Bonded
To Primed Aluminum Structure
• MPS Must Be Kept In Original Unopened Closed Containers, Unmixed At A
Temperature Of Less Than 85°F.
• MPS Has A Working Life Of 100 Minutes For A 50 Gram Kit And 60 Minutes
For A 100 Gram Kit.
• Application / Cure
• MPS Cannot Extend Past 0.010” Of The Edge Of Part (EOP). The Preferred
Application Is To Have The Shim Flush With The Mating EOP. Shim Must Cover
The Entire Flange For Fuel Sealing And Corrosion Requirements.
• Mixed Material Shall Be Applied To The Surfaces To Which It Is To Remain
Adhered.
• Apply The MPS To The Surface In A Sufficient Thickness To Assure Squeeze
Out And/Or Constant Contact During Machining Of MPS.
• MPS Squeeze-out Shall Be Removed Prior To Cure.
• MPS Must Cure For A Minimum Of 8 Hour At Room Temperature.
• Air Voids Must Be Less Than 0.10” X 0.10”.
72
© 2011 Lockheed Martin Corporation
Facilities Requirements
• Work Cell
• The System Must Interface With And Include A Transfer Method To And From
The Machine Tool Transfer Line (MTTL).
• The System Must Fit Into A Maximum Of 24’ x 30’ x 16.6’ High Area. A
Smaller Footprint Is Desired.
• The Work Cell Must Include An Area For MPS Storage.
• The Work Cell Must Have Storage Racks For The OML Control Tool(s) (If
Utilized) And Various End Effectors.
• The Work Cell Must Have An Area For OML Control Tool Prep/Clean Up (If
Utilized).
• The Work Cell Must Safely Contain Any Chemicals.
• The Supplier Must Provide EMCS, Task Lighting, Fire Alarm Interfaces.
• The Work Cell Must Include Safety Guarding As Dictated By Process & LMCO
Requirements.
• LMCO Available Facilities
• Chilled Water, Compressed Air, Industrial Waste, De-ionized Water, Vacuum,
Fire Sprinkler, Natural Gas, 480/277-3ø, 208/120-3ø, Telephone.
73
© 2011 Lockheed Martin Corporation
Automated Equipment Requirements
• Shim Application
• The System Must Have An Effective And Safe Way To Apply MPS.
• The System Must Have A Method To Either Eliminate Or Accommodate
For Air Gaps During MPS Dispense.
• The System Must Have A Working Envelope That Can Apply MPS To
The Understructure Surfaces Plus An Additional 25% In Length (Forward
To Aft) To Accommodate For Any Potential Structural Changes To The
Aircraft Or Other Future Uses.
• The System Must Have A Method To Control Cured Shim Profile
• The System Must Have A Method To Eliminate Or Clean-Up Liquid Shim
Squeeze-Out
• The System Must Be Able To Locate The Structure.
• The System Must Measure The Structure Surface Profile Before And After Shim
Application To Possibly Control Shim Dispense Amount, Safely Complete
Surface Preps Steps, Validate Shim Profile, Etc.
• The System Must Be Able To Perform The Surface Preparation Steps Previously
Detailed
• The System Must Be Able To Handle Multiple End Effectors (Specified By The
Supplier) And An OML Control Tool Weighing Up To 350 Lbs (If Utilized).
74
© 2011 Lockheed Martin Corporation
Control System and Interface Requirements
• Controls
• The System Must Have A Method Of Program Shift For Part Alignment And
MPS Application Accommodating Each New Part.
• The System Must Have A Precision Method For Accurate Dispensing Of MPS,
With Feedback For The Operator.
• The System Must Have Data Retention With A Time And Date Stamp.
• The System Must Read And Display The Material Flow Rate.
• Human Machine Interface (HMI)
• The HMI Must Be User Friendly And Have Few Manual Inputs.
• The HMI Must Have Visual Aids And Feedback For MPS Application.
• The HMI Must Provide Feedback For When Additional MPS Is Needed.
75
© 2011 Lockheed Martin Corporation
General System Design Requirements
• The System Must Complete The Liquid Shimming Process In 15 Hrs (Including Cure
Time).
• The System Shall Accommodate MPS Application To A Forward Fuselage Flange Width
From ~0.85”- 4.25”.
• MPS Must Be Applied To Both Sides Of The Forward Fuselage.
• The System Must Apply MPS So That No Major Rework For Air Bubbles/Voids Is
Required.
• The System Must Apply MPS Properly So That It Does Not Result In Flaking/Chipping
If PMM Milling Is Required.
• The System Must Use As Little MPS As Possible Per Ship.
• The Work Completed Must Flow With The Rest Of The Assembly Process.
76
© 2011 Lockheed Martin Corporation
Appendix C: Supplier Selection
The following table lists information about various dispense and automation suppliers gathered from an industry investigation. Company Notes
Aerobotix
*Response provided with related experience *Robotic mold in place coating project has a lot of transferrable technology (white light, rigid mold tool)
ARM Automation *Develop solutions to automation problems that don’t exist off-the-shelf
Burton Industries *Installed the windshield urethane application cells for Nissan
Durr *LM paint robot integrator
Fastems *Response provided with related experience *LM FF MTTL and Load/Unload/Skin Install (LUSI) station manufacturer
FLX Technologies *Involved in initial robotic shim cell concept testing and demonstration
Fori Automation
*Response provided with related experience *Currently working on an R&D project for robotically applying a two-part sealant onto bulkhead coupons and other airplane sections
Jay Enn *Lockheed tooling and development supplier *Lots of auto industry experience
Kuka *Have bid on several automation projects for LM
Par Systems *LM bulkhead marking machine supplier
RAMPF
*Response provided with related experience *Have demonstrated a small-scale robotic dispensing system to dispense material in an exact amount and vary the amount dispensed in an area if needed. *They can scan the structure, determine the thickness required and dispense the correct amount of material. *Currently working with applications in Europe for a variety of Aerospace applications.
SCA Schucker *Recommended by GM as a leader in robotic dispense
SpenTech *Installed the windshield urethane application cells for Nissan
Waltonen Engineering, Inc *Develop solutions to automation problems that don’t exist off-the-shelf
77
© 2011 Lockheed Martin Corporation
Appendix D: Summary of Supplier Responses from RFI Conference
1 ~1tf•P
•1 '~ '·"" ' lu .. ... 1 ........ ~""':'~ -~~· ·
!»lm
t'l!scw:<'IS¢ l ''""'"
·-··· ... ~~~~ ls,m'Kh
~II.Rllmpl,
+=~ 1
~o,.w.l<Mo .~ '"""'" 1--· , ~· \1!"\ldldl
' and/or . "'"~ IIU, , •
""""'' • ~- lo"'
IOIMII'I:f!lt
I .. ~mo~o~e~rvu- ....
' 1M to.,.. e-o;eov rll\lof
IOIIW!I\l.lln.
l "' OML CO(Itto1 I""" lo'"
' ' 1-""''' ,..,i~ ;Qf'l'e l'llktii!W!t (I.$ 1111-) , ... 5
lOCIOfiOo:l
lo...: ~· "' "':'~
....,.,, • 1 ~
,.
"' Is""""' ,
"'"' I'"""'' J '
""" I~••>
' "'t~:e-et~
I·~• ......... I m,.
, ll(ilqifS
j 1,. ... . 1,., ... , .•
78
© 2011 Lockheed Martin Corporation
Appendix E: Detailed Gage R&R Results
Nikon Laser Radar Results
MSA ANOVA Method Results
Gage R&R Surface Profile Measurement SPC Analysis For Nikon Laser Radar
· -
• Th,j;age R&R lfasiJ11acreptable Measurem<ml Varlabo~tV iss 08~1 TMSmalle<1ht> l't'rrentage The &'tl~ Tht> ~o I ~To HoVE' A Gi!Sl' ~R'"< 10% les~ Thap J0'41s AcCl'Ptable
79
© 2011 Lockheed Martin Corporation
Cognitens WLS400M Results
MSA ANOVA Method Results
Gage R&R Surface Profile Measurement SPC Analysis For Cognitens WLS400M
! ·-
- -
----- -·- ·-·---~--------------~
• The Gage R&R Has Acceptable Measurement Variability (16,29%). The Smaller The Percentage The Better. The Goal Is To Have A Gage R&R < 10%. Less Than 30% Is Acceptable.
80
© 2011 Lockheed Martin Corporation
ATOS Triple Scan Results
MSA ANOVA Method Results
Gage R&R Surface Profile Measurement SPC Analysis For ATOS Triple Scan
!-
• The Gage R&R Has Acceptable Measurement Variability (6.45%). The Smaller The Percentage
The Better. The Goal Is To Have A Gage R&R < 10%. Less Than 30% Is Acceptable.
81
© 2011 Lockheed Martin Corporation
Appendix F: OML Control Tool Test Fixture Details
OML control test fixture fuselage test section
Approximate dimensions of OML control tool test fixture
83
© 2011 Lockheed Martin Corporation
Test fixture modifications to accommodate OML control tool testing