U.S. patent application number 15/007203 was filed with the patent office on 2016-11-03 for novel systems and methods for non-destructive inspection of airplanes.
The applicant listed for this patent is Aerobotics, Inc.. Invention is credited to Douglas Allen Froom, William T. Manak.
Application Number | 20160318632 15/007203 |
Document ID | / |
Family ID | 45938852 |
Filed Date | 2016-11-03 |
United States Patent
Application |
20160318632 |
Kind Code |
A1 |
Froom; Douglas Allen ; et
al. |
November 3, 2016 |
NOVEL SYSTEMS AND METHODS FOR NON-DESTRUCTIVE INSPECTION OF
AIRPLANES
Abstract
A method for managing an airplane fleet is described. The method
includes: (i) developing a gold body database for an airplane model
for each non-destructive inspection system implemented to detect
defects; (ii) inspecting, over a period of time, a plurality of
candidate airplanes of the airplane model, using different types of
non-destructive inspection systems and the gold body database
associated with each of the different types of non-destructive
inspection systems, to identify defects present on the plurality of
candidate airplanes; (iii) repairing or monitoring defects detected
on the plurality of candidate airplanes; (iv) conducting a trend
analysis by analyzing collective defect data obtained from
inspecting of plurality of candidate airplanes; and (v) maintaining
the airplane fleet, which includes plurality of candidate
airplanes, by performing predictive analysis using results of trend
analysis.
Inventors: |
Froom; Douglas Allen;
(Orangevale, CA) ; Manak; William T.; (Fair Oaks,
CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Aerobotics, Inc. |
Wilmington |
DE |
US |
|
|
Family ID: |
45938852 |
Appl. No.: |
15/007203 |
Filed: |
January 26, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14571310 |
Dec 16, 2014 |
9272794 |
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15007203 |
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13876849 |
Mar 28, 2013 |
9031734 |
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PCT/US2011/053190 |
Sep 26, 2011 |
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14571310 |
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61387976 |
Sep 29, 2010 |
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61387980 |
Sep 29, 2010 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B64F 5/00 20130101; G01N
29/44 20130101; B64F 5/60 20170101; G01N 23/00 20130101; G01N
2291/2694 20130101; G01M 5/0033 20130101; G01N 2223/646 20130101;
G01M 5/0091 20130101; G01N 29/04 20130101; G01M 5/0016 20130101;
Y10S 901/44 20130101; B64F 5/40 20170101; G01M 5/0041 20130101;
G01N 23/044 20180201 |
International
Class: |
B64F 5/00 20060101
B64F005/00; G01M 5/00 20060101 G01M005/00; G01N 23/04 20060101
G01N023/04; G01N 29/04 20060101 G01N029/04 |
Claims
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1. A method for repairing airplane defects, comprising: locating a
candidate airplane in space within a robotic envelope to arrive at
a location of said candidate airplane in space, said candidate
airplane being a candidate for inspection by one or more
non-destructive inspection systems; comparing said location of said
candidate airplane with a reference location of a gold body
database airplane to generate an airplane offset, which facilitates
alignment of robots associated with each non-destructive inspection
system; locating, using said airplane offset, a component or a
sub-component of said candidate airplane in space within said
robotic envelope; comparing said location of said component or said
sub-component with a reference location of a gold body database
component or a gold body database sub-component to generate a
component offset or a sub-component offset, which further
facilitates alignment of robots associated with each
non-destructive inspection system; scanning said component or said
sub-component located in space according to a scan plan developed
for each non-destructive inspection system implemented and
developed for said component or said sub-component, and said scan
plan being based on said component offset or said sub-component
offset; detecting presence of defects in said component or said
sub-component; determining whether any of said defects on said
component or said sub-component require repair or engineering
disposition, if one or more defects are detected on said component
or said sub-component; monitoring said one or more defects during a
life cycle of at least one item selected from a group consisting of
said candidate airplane, said component and said sub-component, if
it is determined that said one or more defects do not require
repair; repairing said component or said sub-component, if it is
determined that one or more defects require repair, and said
repairing produces a repaired component or a repaired
sub-component; inspecting said component or said sub-component to
determine whether repair of said component or said sub-component
satisfies a predetermined repair criteria associated with each
category of defect detected; re-repairing said component or said
sub-component one or more times until said predetermined repair
criteria associated with each category of defect detected is
satisfied, if said predetermined repair criteria associated with
each category of defect detected is not satisfied; and developing a
baseline as a historical record for said component or said
sub-component for each said non-destructive inspection system, if
said predetermined repair criteria associated with each category of
defect detected is satisfied.
2. The method of claim 1, wherein said baseline includes a defect
map for each said non-destructive inspection system, and an image
of each said defect on said defect map.
3. The method of claim 1, further comprising assigning said
baseline to an airplane tail number associated with said candidate
airplane.
4. The method of claim 3, further comprising discarding a previous
baseline of said component or said sub-component before said
repairing.
5. The method of claim 1, wherein said detecting includes
generating a defect report, which presents at least one item
selected from a group consisting of category of defect, defect
location and defect dimension.
6. The method of claim 5, wherein said defect location is a
location of a defect in (x, y) coordinates of said component or
said sub-component.
7. The method of claim 6, further comprising: aggregating one or
more defect locations to form a defect map for said component or
said sub-component for each non-destructive inspection system
implemented; overlaying said defect maps produced from each
non-destructive inspection system implemented for said component or
said sub-component to produce an integrated defect map, which is
used as historical record for said component or said
sub-component.
8. The method of claim 7, further comprising: developing an
integrated defect map for each of said plurality of candidate
airplanes to generate a collection of integrated defect maps; and
conducting a trend analysis on said collection of said integrated
defect maps.
9. The method of claim 8, wherein said trend analysis includes at
least one analysis selected from a group consisting of tracking
categories of defects found in said component or sub-component of
said plurality of candidate airplanes through an overlay of images
obtained from one or more systems selected from a group consisting
of an X-ray system, an N-ray system and a laser ultrasonic
inspection system, tracking single site defect location or
multi-site defect locations, tracking defect dimension, tracking
growth of defect over a period of time, tracking low observable
coatings on said plurality of candidate airplanes, and tracking
paint deficiencies on said plurality of candidate airplanes.
10. The method of claim 6, further comprising taking an image of
said defect in said (x, y) coordinates of said component or said
sub-component to produce a defect image to facilitate repair or
engineering disposition of said component or said
sub-component.
11. A system for managing an airplane fleet, said system
comprising: means for developing a gold body database for an
airplane model for each non-destructive inspection system
implemented to detect defects; means for inspecting, over a period
of time, a plurality of candidate airplanes of said airplane model,
using different types of non-destructive inspection systems and
said gold body database associated with each of said different
types of non-destructive inspection systems, to identify defects
present on said plurality of candidate airplanes; means for
repairing or monitoring defects detected on said plurality of
candidate airplanes; means for conducting a trend analysis by
analyzing collective defect data obtained from said inspecting of
said plurality of candidate airplanes; and means for maintaining
said airplane fleet, which includes said plurality of candidate
airplanes, by performing predictive analysis using results of said
trend analysis.
12. The system of claim 11, wherein said means for developing a
gold body database includes a non-destructive inspection system
which includes one or more inspection systems selected from a group
consisting of X-ray inspection system, N-ray inspection system and
laser ultrasonic inspection system.
13. The system of claim 11, wherein said trend analysis and said
predictive analysis is carried out using a computer.
14. The system of claim 11, wherein said repair is carried out
using laser ablation.
15. A system for developing a gold body database for a particular
non-destructive inspection method, said system comprising: means
for locating a reference airplane of a particular model in space
within a robotic envelope; means for locating a component or a
sub-component in space within said robotic envelope such that
during a subsequent inspection of a plurality of candidate
airplanes of said particular model for presence of defects, a
corresponding component or sub-component in each of said plurality
of candidate airplanes is automatically located in space using a
robot; and means for teaching a scan plan for said component or
said sub-component located in space for each non-destructive
inspection system subsequently implemented to detect defects in
each of said plurality of candidate airplanes.
16. The system of claim 15, wherein said means for locating a
reference airplane and said means for locating a component or a
sub-component in space include a machine vision system associated
with each non-destructive inspection system implemented.
17. The system of claim 15, wherein means for teaching a scan plan
includes means for teaching an electromagnetic radiation emitter
and a detector, both of which are configured to a yoke to provide
rotation about at least one axis of pitch, rotate and yaw motion of
said at least one of said electromagnetic radiation emitter and
said detector, said yoke includes a first and a second members,
said first member supports said electromagnetic radiation emitter
and said second member supports said detector such that a distance
between said electromagnetic radiation emitter and said detector is
adjustable.
Description
RELATED APPLICATIONS
[0001] The present application is a divisional of and claims
priority to U.S. patent application Ser. No. 14/571,310, filed Dec.
16, 2014, which is a further divisional of application Ser. No.
13/876,849, filed Mar. 28, 2013, which is a national stage entry of
PCT Application No. PCT/US2011/053190, filed Sep. 26, 2011, which
further claims priority to U.S. Provisional Applications having
Ser. Nos. 61/387,980 and 61/387,976, both of which were filed on
Sep. 29, 2010, which is incorporated herein by reference for all
purposes.
FIELD OF THE INVENTION
[0002] The present invention relates to novel systems and methods
for managing airplane fleets. More particularly, the present
invention relates to managing airplane fleets using non-destructive
inspection methods and predictive analysis.
BACKGROUND OF THE INVENTION
[0003] Frequent tragedies in airplane transportation have caused
concern over the ability of airlines to evaluate the airworthiness
of airplanes within their respective fleets. As airframes age,
characteristics of materials, which make up airframe components,
change due to stresses and strains associated with flights and
landings. Moreover, there is a risk that a state of the airframe
material may go beyond the point of elasticity (i.e., the point the
material returns to its original condition) and extend into the
point of plasticizing or worse, beyond plasticizing to failure. As
a result, periodic inspections and testing are conducted on
airplane components during the airplane component's life cycle.
Such inspections and testing are mandated by governing bodies and
are largely based on empirical evidence.
[0004] Inspections and testing of airplanes are bifurcated into two
areas: destructive testing and nondestructive inspection (NDI),
nondestructive testing (NDT) or nondestructive evaluation (NDE).
"NDI," as this term is used hereinafter in the specification,
encompasses the meanings conveyed by NDT and NDE, as those are
described above. The area of destructive testing, as the name
implies, requires the airplane component under scrutiny to be
destroyed in order to determine the quality of that airplane
component. This can result in a costly endeavor because an airplane
component that may have passed the procedure is destroyed, and is
no longer available for use. Frequently, where destructive testing
is done on samples (e.g. coupons) and not on actual components, the
destructive test may or may not be reflective of the forces that
the actual component could or would withstand within the flight
envelope of the airplane.
[0005] On the other hand, NDI has the obvious advantage of being
directly applied to actual airplane components or sub-components in
their actual environment. Several important methods of NDI that are
performed in a laboratory setting are listed and summarized
below.
[0006] Radiography involves inspection of a material by subjecting
it to penetrating irradiation. Although effective damage detection
has been done using neutron radiation, X-rays are the most familiar
type of radiation used in this technique. Most materials used in
airplane component manufacturing are readily acceptable to X-rays.
In some instances, an opaque penetrant is needed to detect
defects.
[0007] Real-time X-rays, which are frequently used as part of
recent inspection techniques, permit viewing the area of scrutiny
while doing a repair procedure. Some improvement in resolution has
been achieved by using a stereovision technique where the X-rays
are emitted from dual devices which are offset by about 15 degrees.
When viewed together, these dual images give a three-dimensional
view of the material. Still, the accuracy of X-rays is generally no
better than plus or minus 10% void content. Neutrons (N-ray),
however, can detect void contents in the plus or minus 1% range.
The difficulty in implementing radiography raises safety concerns
because a radiation source is being used. Nevertheless, in addition
to detecting internal flaws in metals and composite structures
using conventional non-radiography related methods, X-rays and
neutrons are useful in detecting misalignment of honeycomb cores
after curing, blown cores due to moisture intrusion, and
corrosion.
[0008] Ultrasonic is the most common non-destructive inspection
method for detecting flaws in composite materials. The method is
performed by scanning the material with ultrasonic energy while
monitoring the reflected energy for attenuation (diminishing) of
the signal. The detection of the flaws is somewhat
frequency-dependent and the frequency range and scanning method
most often employed is called "C-scan." In this method, water is
used as a coupling agent between the sending device and the sample.
Therefore, the sample is either immersed in water or water is
sprayed between the signal transmitter and the sample. This method
is effective in detecting defects even in samples that are
substantially thick, and may be used to provide a thickness
profile. C-scan accuracies can be in the plus or minus 1% range for
void content. A slightly modified method call L-scan can detect
stiffness of the sample by using the wave speed, but requires that
the sample density be known.
[0009] Acousto-ultrasonic, another non-destructive inspection
method, is similar to ultrasound except that separate sensors are
used to send the signal and other sensors are used to receive the
signal. Both sensors are, however, located on the same side of the
sample so a reflected signal is detected. This method is more
quantitative and portable than standard ultrasound.
[0010] Acoustic emission, a yet another non-destructive inspection
method, involves detecting sounds emitted by a sample that is
subjected to stress. The stress can be mechanical, but need not be.
In actual practice, in fact, thermal stresses are the most commonly
employed. Quantitative interpretation is not yet possible except
for well-documented and simple shapes (such as cylindrical pressure
vessels).
[0011] Thermography (sometimes referred to as "IR thermography") is
yet another non-destructive inspection method that detects
differences in relative temperatures on the surface undergoing
inspection. Differences in relative temperatures on the inspected
surface are produced due to the presence of internal flaws. As a
result, thermography is capable of identifying the location of
those flaws. If the internal flaws are small or far removed from
the surface, however, they may not be detected. In thermography,
there are generally two modes of operation, i.e., an active and a
passive mode of operation. In the active mode of operation, a
sample is subjected to stress (usually mechanical and often
vibrational) and the emitted heat is detected. In the passive mode
of operation, the sample is externally heated and the resulting
thermal gradients are detected.
[0012] Optical holography, a yet another non-destructive inspection
method, uses laser photography to give three-dimensional pictures,
which are called "holography." This method detects flaws in samples
by employing a double-image method, according to which two pictures
are taken while stress is induced on a sample between the times
when a picture is taken. This method has had limited acceptance
because of the need to isolate the camera and the sample from
vibrations. However, it is believed that phase locking may
eliminate this problem. The stresses that are imposed on the sample
are usually thermal. If a microwave source of stress is used,
moisture content of the sample can be detected. For composite
material, this method is especially useful for detecting debonds in
thick honeycomb and foam sandwich constructions. A related method
is called shearography. In this method, a laser is used with the
same double exposure technique as in holography where stress is
applied between exposures. However, in this case an image-shearing
camera is used in which signals from the two images are
superimposed to provide an interference pattern and thereby reveal
the strains in the samples. According to this method, strains are
detected in a particular area, and the size of the pattern can give
an indication of the stresses concentrated in that area. As a
result, shearography allows a quantitative appraisal of the
severity of the defect. The attribute of quantitative appraisal,
relatively greater mobility of shearography over holography, and
the ability to stress the sample using mechanical, thermal, and
other techniques, has given this method wide acceptance since its
introduction.
[0013] Unfortunately, current commercial industry inspection and
repair methods suffer from several drawbacks. By way of example,
the above described non-destructive inspection methods are largely
limited to laboratory analysis. The current commercial industry
inspection and repair methods are inefficient, costly and not
standardized. As another example, these inspection and repair
methods have seen little or no changes in the past 20 or 30 years
and have not solved the "Aging Airplane" safety problems. As it
stands now, inspection of airplane components are limited to the
"Tap Test," visual inspection, and Eddy Current analysis.
Furthermore, inspection timetables are developed and updated
primarily as a function of anecdotal evidence, all too frequently
based on airline catastrophes.
[0014] Despite a wealth of diagnostic tools mostly available in
laboratory settings for detecting defects, what is, therefore,
needed are novel systems and methods for effective airplane fleet
management and that do not suffer from the above-described
drawbacks encountered by the current airplane inspection methods
and systems.
SUMMARY OF THE INVENTION
[0015] In view of the foregoing, in one aspect, the present
invention provides systems and processes that use one or more NDI
systems, which reveal different types of defects on the same
components.
[0016] In another aspect, the present invention provides a method
for managing an airplane fleet. The method includes: (i) developing
a gold body database for an airplane model for each non-destructive
inspection system implemented to detect defects; (ii) inspecting,
over a period of time, a plurality of candidate airplanes of the
airplane model, using different types of non-destructive inspection
systems and the gold body database associated with each of the
different types of non-destructive inspection systems, to identify
defects present on the plurality of candidate airplanes; (iii)
repairing or monitoring defects detected on the plurality of
candidate airplanes; (iv) conducting a trend analysis by analyzing
collective defect data obtained from inspecting of plurality of
candidate airplanes; and (v) maintaining the airplane fleet, which
includes plurality of candidate airplanes, by performing predictive
analysis using results of trend analysis.
[0017] The construction and method of operation of the invention,
however, together with additional objects and advantages thereof,
will be best understood from the following descriptions of specific
embodiments when read in connection with the accompanying
figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is a perspective view inside a robotic envelope of
some major components of a fleet management system, in accordance
with one embodiment of the present invention.
[0019] FIG. 1A shows one robotic movement system, in accordance
with one embodiment of the present invention, through the
X-axis.
[0020] FIG. 2 is a front view of a fleet management system, in
accordance with preferred embodiments of the present invention, for
managing a commercial airplane fleet.
[0021] FIG. 2A shows an attachment, in accordance with preferred
embodiments of the present invention, to a rail in the X-axis as
shown in FIG. 1A.
[0022] FIG. 3 is a side view of a commercial airplane fleet
management system shown in FIG. 2.
[0023] FIG. 3A shows a vertical mast support, in accordance with
preferred embodiments of the present invention.
[0024] FIG. 4 is a side view of an N-ray system, in accordance with
preferred embodiments of the present invention.
[0025] FIG. 4A shows a section of the mast, in accordance with
preferred embodiments of the present invention.
[0026] FIG. 5 is a side view of an X-ray system, in accordance with
preferred embodiments of the present invention.
[0027] FIG. 5A shows some major components of a mast drive system,
in accordance with preferred embodiments of the present
invention.
[0028] FIG. 6 is a side view of an N-ray yoke, in accordance with
one embodiment of the present invention.
[0029] FIG. 7 is a side view of an X-ray yoke, in accordance with
one embodiment of the present invention.
[0030] FIG. 8 is a side view of an adjustable lower leg of an N-ray
yoke, in accordance with preferred embodiments of the present
invention.
[0031] FIG. 9 is a side view of an adjustable lower leg of an X-ray
yoke, in accordance with preferred embodiments of the present
invention.
[0032] FIG. 10 is a side view of pitch, rotate and yaw of a laser
yoke, in accordance with preferred embodiments of the present
invention.
[0033] FIG. 11 is a front view of a laser addressing the airplane,
in accordance with preferred embodiments of the present
invention.
[0034] FIG. 12 is a front view of a laser addressing an airplane
and the configuration of the laser and the airplane is shown in
accordance with preferred embodiments of the present invention.
[0035] FIG. 13 is a top view of a fleet management system, in
accordance with preferred embodiments of the present invention.
[0036] FIG. 14 is a process flow diagram for an airplane fleet
management process, in accordance with preferred embodiments of the
present invention.
[0037] FIG. 15 is a process flow diagram for a method of developing
a gold body database, in accordance with preferred embodiments of
the present invention, of a particular airplane model and that is
developed for each NDI system implemented to detect defects.
[0038] FIG. 16 shows a plan view of an exemplar airplane having
various components and sub-components.
[0039] FIG. 17 shows a scan plan, in accordance with preferred
embodiments of the present invention, for inspecting an exemplar
right leading edge box of an airplane stabilator using a
Maneuverable N-ray Radiography System ("MNRS").
[0040] FIG. 18 shows a scan plan, in accordance with preferred
embodiments of the present invention, for inspecting an exemplar
right leading edge box of an airplane stabilator using a
Maneuverable X-ray Radiography System ("MXRS").
[0041] FIG. 19 shows a defect map, according to preferred
embodiments of the present invention, prepared by overlaying
defects found by NNRS and MXRS inspection of an exemplar right
leading edge box of an airplane stabilator.
[0042] FIG. 20 shows an X-ray and N-ray imaging configurations,
according to preferred embodiments of the present invention,
implemented to obtain a volumetric measurement.
[0043] FIG. 21A shows a defect map, according to preferred
embodiments of the present invention, prepared by overlaying defect
(e.g., moisture, corrosion and voids) detection carried out by MNRS
and MXRS inspection of an exemplar horizontal stabilator.
[0044] FIG. 21B shows an exemplar data summary of various defects
found in an exemplar horizontal stabilator.
[0045] FIG. 22 shows an exemplar table resulting after conducting a
trend analysis for defective components, which require repair or
disassembly.
[0046] FIGS. 23A and 23B shows a process flow diagram, in
accordance with preferred embodiments of the present invention, for
managing or repairing defects found in an airplane's component or
sub-component using an NDI system and when the repair requires
removing the defective component or sub-component from the
airplane.
[0047] FIGS. 24A and 24B shows a process flow diagram, in
accordance with preferred embodiments of the present invention, for
managing or repairing defects found in an airplane's component or
sub-component using an NDI system and when the repair is carried
out on an intact airplane (i.e., the defective component or
sub-component is not removed from the airplane).
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0048] In the following description, numerous specific details are
set forth in order to provide a thorough understanding of the
present invention. It will be apparent, however, to one skilled in
the art that the present invention is practiced without limitation
to some or all of these specific details. In other instances,
well-known process steps have not been described in detail in order
to not unnecessarily obscure the invention.
[0049] The present invention recognizes that currently, commercial
safety integrity is continually compromised by not determining the
extent of an airplane's structural defects. To this end, the
present invention is directed to systems and processes that perform
NDI of airplanes and components or sub-components thereof. Certain
key aspects of the present invention involve systematic and
automated inspection methods and apparatuses coupled with
comparison to a gold body database (also known in the art as a
"reference" or "standard") to allow for predictive analysis that is
based on trend analysis of defects found in a plurality of
candidate airplanes. A candidate airplane, as the term is used in
this specification, refers to an airplane that undergoes inspection
for defect detection. An airplane fleet includes a plurality of
candidate airplanes.
[0050] NDI systems and methods of the present invention are
contained inside or carried out in a structure, preferably
configured as an enclosure. The structure includes walls, a
ceiling, and a floor. A hangar door entrance is defined in a wall.
Moreover, the structure utilizes concrete as shielding to attenuate
the emission of radiation to the outside of the enclosure. In
certain embodiments of the present invention, various safety
measures may be implemented. By way of example, interlocks are
provided to prevent the emission of radiation when personnel might
be endangered because a door to a room, containing excessive
amounts of radiation, is opened. Other measures, such as key
controls and password authentication may be provided to prevent
emission of radiation or other potentially hazardous activities,
such as motion of robotic systems, without approval of authorized
personnel. Radiation monitoring and alarm systems are preferably
provided to detect abnormal radiation levels and provide
warning.
[0051] For each NDI system or method implemented to detect defects,
corbels are provided to support multiple robots. Walls, ceiling,
and hanger door entrance are designed to support the corbels,
permitting translation (e.g., along X-axis) across the items under
inspection, testing or evaluation. Corbels designed to accommodate
structural loading while maintaining accuracy and repeatability of
robot position over six axes of movement, which are described
below, within a narrow range of tolerances better than plus or
minus about 0.250 inches, and preferably better than plus or minus
about 0.120 inches. They accommodate structural loading of various
types, e.g., floor loading, wind loading, loading in earthquake
zones and loading from the mass of the robots.
[0052] In preferred embodiments, inventive NDI systems for
inspecting an airplane component or sub-component include a beam
arrangement for supporting and allowing translation of a carriage.
The beam is mounted on rails which are attached to the corbels by
the means of end trucks, providing movement along the length of the
facility or X-axis. The carriage moves along the length of the beam
providing movement in the Y-axis. A telescoping tube or mast is
attached to the carriage in a vertical position, providing movement
in the Z-axis. At the bottom of the mast, three axes of movement
are provided, i.e., pitch, rotate, and yaw of the yoke to which the
inspection apparatus is attached. The translations permit the
system to scan an intact airplane to the component level or the
sub-component level. The carriage is coupled to a mast structure
for supporting and allowing translation of a yoke.
[0053] The mast comprises a plurality of tubes that can move
telescopically to provide a large range of motion in a vertical
direction, and at the same time, supporting large amounts of mass.
In one embodiment of the invention, the beam arrangement is located
overhead, for example, near the ceiling of the building. The
building and beam arrangement form a gantry for supporting the
carriage as well as the yoke which is mounted on the mast. In a
preferred embodiment of the present invention, the yoke includes
two members that may be extended telescopically to adjust the
throat depth of the yoke.
[0054] In another embodiment of the present invention, the yoke is
configured to accommodate surfaces that change a camber of the
wing. In particular, configurations of the first member support a
beam source and the second member supports an imaging device. In an
alternative embodiment of the present invention, the mast supports
a laser ultrasonic scanner. In this embodiment, a laser ultrasonic
scanner is attached to the mast of the inspection and testing
apparatus and configured with rotational axes to allow scanning in
a plurality of directions across complex surfaces of the airplane,
including its components or sub-components.
[0055] Real-time X-ray radiography is accomplished in motion
utilizing multi-axis movement of robots to scan at a rate that is
between about one and about three inches per second and at a
magnification that is between about three times and about five
times. Any pendulum or sway effect at the bottom of mast (with yoke
attached) causes a real-time radiography image to unfocus, or in
the alternative, get distorted and become unreadable to an
operator. The problematic pendulum or sway effect is believed to be
caused by two separate resonating frequencies, i.e., the
fundamental frequency of the robot based upon the mass and rigidity
of the robot structure, and the robot mounting to the housing
facility which has its own resonating frequency when one ore more
robots are in motion. Providing two separate parallel bridges
mounted to single end trucks with carriage straddling both parallel
bridges and the mast located between the two separate bridges
yields acceptable results so long as the length of the bridge does
not exceed a certain length, typically about 180 feet. Providing a
single rail bridge typically permits a length of the bridge not to
exceed about ninety-six feet.
[0056] Existing hangar structure may be modified or new facilities
may be built to attenuate any pendulum effect and resonating
frequencies that could distort robotic inspection readings.
Facility modification or new design would be based upon three
separate requirements, i.e., seismic, resonate frequency of the
facility with one or more robots in motion, and the robotic
envelope. Site surveys may determine the seismic activity, ground
water location, type of soil, soil compaction and may result in
building the facilities foundation as an isolation pad. The
resonate frequency of the facility with the robots in a static
position are modeled to evaluate the pendulum effect of the robots
and to determine the amount of reinforcement of steel and concrete
needed to meet frequency requirements for the facility's bearing
walls. It is believed that as the robots move closer to the hangar
door, the pendulum effects become unacceptable. Therefore,
appropriate modifications may be made to the concrete hangar door
header, and a lateral tie or footer may be provided at the ground
level. Such modifications rigidify the side of the structure
containing the hangar door to attenuate any resonate frequencies to
acceptable levels during the airplane inspection using robots. The
robotic envelope is determined based on the type of airplane that
is subject to inspection within the facility. The envelope is
factored in, and any resonate frequencies are attenuated in order
to provide inspection accuracy and repeatability.
[0057] Inspection of airplane wings requires the control surfaces
to be extended to allow for a total wing inspection. This wing
configuration causes sharp radial surface turns at the fore and aft
ends of the wings' leading and trailing edge surfaces and the
inability for a normal "C"-shaped yoke to conform to these areas to
perform a total inspection of the part. The solution to this
problem is to provide a modified C-shaped yoke with a lower arm
having an articulating member, akin to a double joint, in order to
allow the lower arm to tuck underneath the control surface.
[0058] When the preliminary designs of the buildings, robots, and
end effectors are completed, modeling of the entire system may be
performed to assure accuracy and repeatability of robot
positioning. Oscillatory excitation of the system components
resulting from robot motion and acceleration and deceleration may
be analyzed. Designs of the system components may be modified to
maximize desirable characteristics, such as accuracy and
repeatability of robot positioning, while minimizing undesirable
characteristics, such as unwanted oscillatory excitation of system
components.
[0059] FIGS. 1-13 described below show various systems and
sub-systems used in certain embodiments of the present invention,
to implement, among other things, the methods of the present
invention. A Robotic Overhead Positioner (ROP), (e.g., as shown in
FIG. 1) is a gantry robot that resembles an overhead crane. The ROP
allows movement in three linear directions (i.e., X, Y, and Z) and
three rotational directions (i.e., Yaw, Pitch and Roll described
below). Generally, to move in each of these directions, it uses a
variable-speed DC motor 14 (which is shown in greater detail in
FIG. 1A), a gearbox 16, and an encoder 22 including a drive
mechanism 18 having wheels 52. Power to turn the motor (thus moving
the robot) is supplied by a controller 20. Each motor 14 includes
encoder 22, which instructs controller 20 regarding distance of
travel. Motor 14 also includes a solenoid energized electric disc
brake 24, which keeps the robot in a frozen position whenever
controller 20 is not supplying power to motor 14. For each
direction robot 12 is capable of moving, there is also an
absolute-positioning resolver 26, which instructs controller 20
regarding the robot's location via encoder 22. Limit switches 28
inside resolver 26 prevent the motor 14 from driving wheeled drive
mechanism 18 beyond its end of travel. Power to motor 14 and
signals to controller 20 are supplied via cables 32 (as shown in
FIG. 1), which are fully insulated and which have military-standard
connectors. As shown in FIG. 1A, heavy-duty frictionless bearings
36 are used throughout, in accordance with one embodiment of the
present invention, to maximize system reliability.
[0060] As shown in FIGS. 1 and 1A, a bridge 38 moves in a first
linear direction (i.e., X-axis) on a runway 40. Runway 40 is made
of sets of two parallel rails 42 (shown in FIG. 2) mounted on rail
ledges 44 (shown in FIG. 2A). FIG. 2 shows one rail 42 on each
sidewall 46 (and two rails 42 on a central corbel 43) of the
inspection bay 48. Rails 42 have adjusters 50 for leveling and
parallel alignment, as shown in FIG. 2A.
[0061] Wheels 52, as shown in FIGS. 1A and 2, are designed to
support bridge end trucks 38. A pair of wheels 52 rides on rails
42. Each pair of wheels has its own motor 14 and its own resolver
26. Bridge 38 encloses and supports drive mechanism 18. As motor 14
turns, wheels 52 turn, moving bridge 38 back and forth on the rails
42. The dual motor 14/resolver 26 scheme enables controller 20 to
avoid bridge 38 skewing off the rail 42. If limit switches 28 in
the resolver 26 were to fail, thereby allowing an operator to move
bridge 38 to the very end of the rails 42, shock absorbers 54 on
bridge 38 and end-stops 56 on rails 42 prevent bridge 38 from
striking walls 58. A crank 59 is provided on each end of bridge 38
as a manual backup motion system to allow the bridge to move
without motor 14.
[0062] FIGS. 1 and 2 show the second linear direction (i.e.,
Y-axis) where a trolley 60 moves along a span 39 which extends
between two rails 42. Similar to X-axis, trolley 60 moves along
span 39 in a dependent relationship, as shown in FIG. 3A. Span 39
is box-shaped and has spaced parallel vertical rails 64 and spaced
parallel horizontal rails 68 forming an enclosed box. The weight of
trolley 60 is bearing on its wheels 52 that ride on opposed outer
faces of each vertical rail 64. As motor 14 turns, wheels 52 also
turn, moving trolley 60 left and right (along Y-axis) on span 39.
One wheel set 52 rides on a lower edge of one vertical rail 64 and
another wheel set 52 rides on a top edge of opposite vertical rail
64 to keep trolley 60 (and thus the mast 70) from tilting. Span 39
preferably has an upwardly projecting central crown 68 (as shown in
FIG. 2) of about one-half inch when unloaded and bows one-half inch
downwardly when trolley 60 moves to the middle of span 39. Thus,
span 39 is, therefore, normalized (i.e., level) along a length. If
limit switches 28 in resolver 26 were to fail, allowing an operator
to move trolley 60 to the end of rails 42, shock absorbers 54 on
span 39 and end-stops 56 on the span's ends prevent trolley 60 from
striking walls 58. A crank 62 is provided on each trolley 60 as a
manual backup system to allow reorientation of trolley 60 along
span 39. The trolley's drive is similar to that shown in FIG.
1A.
[0063] The third linear direction (i.e., Z-axis) moves mast 70 on
trolley 60 up and down via positioner 92, which is shown in FIG.
5A. Mast 70 is preferably capable of hoisting at least 5000 pounds,
and is designed such that the failure of any single part of the
system will not cause its sensor array, located at the free end of
mast 70, to fall to the bottom of mast travel. Mast 70 is a
box-shaped inner telescoping tube 74 with wheels 76 on an inner
surface of box-shaped outer tube 78 riding on rails 80 as shown in
FIG. 4A. Mast 70 is hoisted by dual cables 84 (shown in FIG. 4A and
5A) and has two drums 86 (only one is shown to simplify
illustration). As motor 14 turns, each drum 86 deploys a cable 84,
hoisting inner tube 74. Each drum 86 has a brake 88 mounted to its
drive shaft 89 to prevent tube 74 from falling if one brake 88
should fail. A load sensing mechanism 90 embodied as an overload
clutch is provided on hoisting system brake 88 to stop the mast if
a sensor supporting yoke 100 (e.g., as shown in FIG. 2) should
catch on an object, as it is hoisted up or down or if there is a
system overload. This load sensing mechanism 90 will also stop
positioner 92 when one component of the hoist system quits
operating. For a backup system, each cable/drum system is capable
of hoisting the mast at full load. If the hoist were to over-speed,
another sensor 94, monitoring amperage would again perform to
trigger an emergency stop. A crank 79 of FIG. 1 is provided on each
mast 70 as a manual backup motion system.
[0064] Three rotational axes are incorporated into each inspection
yoke 100, as shown in FIGS. 6 through 9. Yoke 100, as mentioned
before, is a C-shaped structure with an adjustable mouth "M" which
spans the gap between the sources and receiver. Two X-ray sources
102, 104 (as shown in FIGS. 7 and 9), having differing outputs are
mounted on top support 101 of yoke 100 and an image receiver 106 is
mounted on the bottom by arm 103. Yoke 100 may also support a
collision-avoidance paneling 110. The paneling is a pressure
sensitive sheath and is mounted on all lower extremities of mast
70. The pressure sensitive paneling prevents gross contact with the
airplane by mandating a stop signal in the presence of a triggering
pressure. During the scanning of the airplane surfaces, the surface
(e.g., wing) is positioned between X-ray sources 102 and 104 and
N-ray source 108 (shown in FIGS. 6 and 8) and imager 106. A film
source 107 may supplement or supplant imager 106.
[0065] A first rotational axis 112 (i.e., Yaw) rotates inspection
yoke 100 in a horizontal plane at the bottom of mast 70. A second
rotational axis 114 (i.e., Pitch) pivots inspection yoke 100 in a
vertical plane at the bottom of mast 70. A third rotational axis
116 (i.e., Roll) rotates inspection yoke 100 in a plane at the end
of the pitch axis; this plane is oriented perpendicular to the
pitch axis. It is noteworthy that X-ray sources 102 and 104, and
N-ray source 108 are independently rotatable about 116a. Further,
each arm (e.g., bottom arm 103 or a side arm) may change in length
as shown by double ended arrows "A" as shown in FIGS. 8 and 9. A
link 117 connecting bottom and side arms 103, 113 can rotate about
curved arrow "C" to adjust the dimension of adjustable mouth "M,"
in conjunction with the telescoping arm's length along arrow
"A."
[0066] X-ray sources 102 and 104 are mounted on a movable support
such that only one of the two sources may be aimed at imager 106
during an imaging event by rotation about 116a. This support,
called a turret 120 (shown in FIG. 7), is rotated 90 degrees by a
stepper motor 122 (shown schematically in FIG. 9). Only the X-ray
source aimed at imager 106 may be activated unless a permanent
record is desired via a film source 107 which rotates in the place
of imager 106. Alternatively, the film source 107 can rotate about
axis 119 (denoted by arrow 119a in FIG. 7) to orient the film
source 107 to X-ray source 102 and 104. X-ray sources 102 and 104
are indexed into position as a function of the object being
scanned, its thickness, and its composition (e.g., composition
versus metal). Imager 106 is an image intensifier, which directs
the X-ray image to the control room operator CRT screen. A bottom
arm 103 may also carry another type of X-ray imaging system 111 for
backscatter X-ray (reverse geometry X-ray). A sender unit 111 is
shown mounted adjacent imager 106. Photo-multiplier tubes 109
(shown in FIG. 1) are positioned inside the airplane to receive
digital images from sender 111. Receivers 105 are also placed on
the inside of the production airplane structures and direct digital
imaging information to be sent to the control room operators. Yoke
manipulative and imaging capabilities specified for either the
N-ray or X-ray could be incorporated in the other.
[0067] Because of the varying change in the thickness of airplane
internal structures (such as wings), the X-ray source output (KVP
Kilovoltage Penetrating Power, MA Milliamps Current) is preferably
controlled by robotic coordinates to allow ramp up or ramp down of
X-ray penetrating power. This allows clear and precise imaging. It
also allows an operator to focus attention to the viewed images and
not constantly adjusting output due to the change in the airplane
structure material thickness. More importantly, each and every
airplane is inspected based on the same settings, conditions and a
relevant gold body database.
[0068] Yoke 100 also contains a heat gun 150, somewhat like a hair
dryer. This is used on both the X-ray and N-ray yokes to allow an
operator to verify and distinguish the presence of moisture, water
or fuel inside the aluminum or composite bonded structure. Current
industry NDI methods and systems cannot distinguish the difference
between moisture and sealant. Once a defect area is detected by
either an X-ray or N-ray inspection system or method, heat is
applied by the yoke's heat gun 150 to that specific area. Heat out
generation is monitored by an infrared pyrometer 151 in order not
to exceed a limit, preferably 160 degrees Fahrenheit, on the
structure where the heat is applied. If moisture is present, the
applied heat causes migration of the fluid away from the heat
source due to expansion of the air within the heated structure
area. Heat images are taken before and after heating. Alternate
"before and after" images flash on the operator's CRT screen and
image picture subtraction is accomplished. The difference allows
the operator to watch moisture migration. This procedure is
important in locating water entry paths within the airplane
structure or component.
[0069] A laser ultrasonics ("laser UT") apparatus, 130 is also
mounted to gantry robot system 12. Like yoke 100, apparatus 130
(shown in FIG. 10) is coupled to a carriage 132 (shown in FIG. 2)
and a mast 134 mounted to the carriage 132 with rotational axes as
described for the previous trolley and mast. Laser UT apparatus 130
allows movement in X-axis (along line L), and Y-axis (up and down
along line G), and rotational movement (e.g., about arrows 112,
114, 116) by using stepper motors 135. The rotational movement of
the laser UT apparatus allows it to reach underside areas of the
fuselage while being support by gantry robot system 12 that is
above the fuselage, as shown in FIGS. 10, 11 and 12. A mirror 136
of FIG. 10 receives laser energy "L" from within housing 130 and
distributes the energy on the scanned surface by mirror rotation,
indexing and mast rotation and scanning, as shown in FIG. 12.
Reflected laser light provides further diagnostics.
[0070] A laser UT gantry robotic system is provided for inspection
of both intact airplane and components removed from the airplane.
In preferred embodiments of the present invention, component
imaging systems such as X-ray, N-ray and laser UT are utilized for
pre-inspection of airplane spare components, as well as
post-inspection of repaired components removed from the airplane to
ensure adequate repair process and procedures.
[0071] The embodiments of present invention include robotic imaging
inspection methods and systems, such as real-time X-ray, N-ray and
laser UT. When used separately, certain imaging inspection methods
find certain airplane structural defects. According to certain
embodiments of the present invention, N-ray imaging inspection
methodology locates and images structural integrity defects such as
one selected from a group consisting of internal moisture,
corrosion, internal fuel leaks, and voids in sealants. Similarly,
real-time X-ray imaging inspection methodology finds and images
structural integrity defects such as one selected from a group
consisting of moisture, corrosion, cracks, fatigue damage,
collateral damage, flaws, deformation, and foreign objects. Laser
UT inspection methodology finds and images structural integrity
defects such as one selected from a group consisting of disbond,
delamination, impact damage, material life, porosity and voids.
[0072] Defects are preferably evaluated against a predetermined
accept/reject criteria to determine corrective maintenance and
repair actions, as explained below in connection with a step 2310
of FIG. 23A. In certain preferred embodiments of the present
invention, defects are monitored over time to determine the
defect's growth in length, width and depth. A baseline may be
accomplished using X-ray, N-ray and laser UT volumetric measurement
techniques, and by identifying size (length, width, and depth) and
location of each defect in all components of an airplane. This
method provides laminography views through the wing or any
component part to locate exact position of a defect within multiple
layers of a component's structural material. The defect may be
identified in multiple material layers existing between the
component's inner most layer and outer most layer of material. By
way of example, the method provides two dimensional and three
dimensional laminography views of a disbond or void within a
component's multi-layer composite material to determine length,
width and depth of the defect at a specific X-axis, Y-axis and
Z-axis position within the material and between specific layers of
a component's composite material.
[0073] The laser UT methodology locates defect regardless of a
composite or metal structure's configuration. When used in
combination on any given airplane or component, or when monitoring
a partial or complete airplane fleet or partial or complete fleets
of like airplanes, various types of structural defects and
discrepancies may be identified on a component/sub-component or on
a series of multiple components at a single location or on multiple
locations on each component/sub-component with high precision to
delineate a defect or deficiency trend within the
component/sub-component or series of components/sub-components. For
example, the defects or deficiencies may be further analyzed and
identified by the components'/sub-components' part number, serial
number and use on a given airplane's tail number. Each defect's or
discrepancy's size may be recorded and tracked by inspection
number, number of flying hours, number of takeoffs and landing
cycles and number of missions during the component's life cycle. In
certain embodiments of the present invention, each defect's or
discrepancy's growth in size is recorded and tracked by date and
time, inspection, maintenance and repair location, inspection
number, number of flying hours, number of takeoffs and landing
cycles and number of missions during the component's life
cycle.
[0074] Future structural defects and deficiencies may be formulated
and predicted on a component-by-component basis and may be based on
defect growth within a component. Furthermore, a defect growth rate
within an airplane component may be predicted, which in turn may
restrict an airplane fleet's maximum flight speed to inhibit
further defect growth. Predictive analysis may also be used to
estimate the time between maintenance for the component, inventory
requirement to replace or repair the component or parts within the
component, and associated workflow days and budget requirements.
Structural problems may be formulated and predicted by model and
series of airplane, by matching components' part number and serial
number to airplanes' tail number in the airplane fleet. An airplane
component's part number, and serial number, and historical
inspection, maintenance and repair data is captured, entered or
downloaded and stored by date and time, inspection, maintenance and
repair location, inspection number, number of flying hours, number
of takeoffs and landing cycles and number of missions on an a
non-volatile, solid state computer chip containing flash memory and
wireless Blue Tooth or other form of wireless communications that
is embedded in the component. The computer memory chip is readable
by a wireless communication data capture and display device without
airplane or component disassembly.
[0075] In accordance with embodiments of the present invention,
laser UT utilizes a pulsed laser to introduce an ultrasonic sound
wave into composite or metal material. A pulse laser source is
moved along an airplane or a component part's surface by the means
of a translation mirror moving in X and Y position to achieve a
roster scanning of the airplane or the component of the airplane.
The pulse length for scanning (time the laser beam is on the part's
surface) can be accomplished at a rate of up to 240 pulses per
second. The present state-of-the-art technologies are limited to
surface scanning, and they do not ablate composite materials or
surface coatings.
[0076] In the current manufacturing process of composite materials
to achieve a desired shape, a bond former is utilized to nest
composite cloth or prepreg resin systems. This bond former is made
of metal or composite material and is coated with mold release to
allow the newly cured part to be removed without destroying the
part or bond former. The mold release becomes impregnated into the
resin system of the new part and must be removed prior to
application of paint, adhesives or other coatings to achieve proper
bond strength and surface tension for adhesion.
[0077] The present state-of-the-art methods of removing mold
release or surface coatings such as paint is accomplished by manual
and mechanical means such as hand sanding or high pressure media
blast. These manual and mechanical stripping methods expose the new
part's composite fibers to excessive damage when aggressively
attempting to remove mold release from the resin system.
[0078] Laser UT to inspect and verify airplane component composite
condition is modified and enhanced, in accordance with certain
embodiments of the present invention, to include laser ablation to
precisely and effectively remove surface coatings on composite
material during the inspection process. This can be accomplished,
for example, by increasing the pulsed laser output, or modifying
the length of the pulse, or a combination of modifying laser output
and pulse length. Ablation is based on a gain in power of the light
source and pulse rate (pulse length in time on the component's
material surface). Ablation power and pulse rate may vary based on
the type of material and thickness of the coating that is being
removed. Laser UT can measure a coating thickness before and after
stripping the coating. As a result, methods, as provided by certain
embodiments of the present invention, affect the resin system or
matrix only, not the composite fibers of the component's material.
As such, the integrity of the component is not affected by this
method of coating removal. During manufacturing and repair prior to
the airplane component being placed in service, this method
provides precise stripping of surface coating, a reduction in
manufacturing and repair time, and cost savings during final
material surface coating preparation, final material surface
tension preparation for adhesive bonding application, and material
surface coating stripping in preparation for repair. In-service
airplane requires periodic inspection, maintenance and repair which
require removal and reapplication of painted or coated services.
The method described above provides inspection and removal of paint
and other coatings during a single laser UT inspection
application.
[0079] Considering the drawings, wherein like reference numerals
denote like parts throughout the various drawing figures, reference
numeral 10 of FIG. 1A is directed to non-destructive inspection and
testing systems, according to one embodiment of the present
invention, for airplane components and/or sub-components.
[0080] Each NDI system discussed above has its own robot. Each
individual robot has a "home" position to verify accuracy and to
correct possible relocated robot movement (such as from
earthquakes). An example of this is the home position fixture for
the X-ray and N-ray inspection systems. The home position fixture
is preferably inverted "L" shape flat plate steel 180 (which is
found in FIG. 2) whose vertical leg 180b is attached to wall 46
with approximately four feet overhang provided by horizontal leg
180a from the wall. The flat steel plate overhang horizontal leg
180a is parallel to the concrete facility floor. A small, about
0.030-inch hole 181 is drilled through the center of an overhang
plate 180a. With the X-ray system on, a CRT screen contains
crosshairs (like a hunting rifle scope) to locate the crosshairs in
the center of the overhang hole at 5.times. geometric
magnification. This provides a home position initialization step
(calibration) and is preferably performed prior to each and every
airplane inspection and also for all robots and each inspection
method (X-ray, N-ray and Laser UT). Laser alignment relies on a
uniform thickness plate 183 having at least two variations V.sub.1
and V.sub.2 from the uniform thickness at known locations. The
laser, when scanning the variations (e.g., a counter-bore),
preferably reflects the known variations as a function of relative
length and distance. In FIG. 2A, rails 42 can be aligned by oval
slots 51 allowing motion of rail 42 relative to its support plate
44. A J bolt supports rail 42 and plate 44 in wall 58. A threaded
free end of J bolt 50 includes washers "W" and nuts "N" for
vertical and lateral truing.
[0081] As previously stated, the present invention has at least one
and preferably three or more robots. The use of multiple robots
provides several advantages. By way of example, multiple robots
allow simultaneous inspection of several areas of an airplane,
thereby reducing the time required to inspect an airplane. As
another example, multiple robots avoid the need for a single long
supporting beam, which would reduce positioning accuracy and
repeatability. As yet another example, multiple robots allow each
robot to be specifically designed to inspect particular areas of an
airplane, thereby allowing accommodation of special attributes of
various areas.
[0082] Corbels 12, 43 and rails 42 are provided to support multiple
robots. The walls 58, ceiling 59, and hanger door entrance 61 are
designed to support corbels and rails, which permit linear
translation. The location of corbels within the structure, e.g., an
airplane hanger, is designed to accommodate structural loading (due
to weight of the robot, robotic movement yielding unaccepted
resonate frequencies, etc.) while maintaining accuracy and
repeatability of robot position over six axes of movement within a
narrow range of tolerances to plus or minus about 0.120 inches. The
structure accommodates structural loading of various types, for
example floor loading, wind loading and loading from the mass of
the robots.
[0083] The inspection facility is designed to protect personnel
from radiation hazards (including X-rays and neutrons). Shielding
63 (of FIG. 2A), including shielding of walls, doors, and windows
is provided. Interlocks 201 (of FIG. 3) are provided to prevent the
emission of radiation when personnel might be endangered, such as
when a door is opened. Other measures, such as key controls and
password authentication are provided to prevent emission of
radiation or other potentially hazardous activities, such as motion
of robotic systems, without approval of authorized personnel.
Radiation monitoring and alarm systems 203 are provided to detect
abnormal radiation levels and provide warning.
[0084] One example of a technique used to provide radiation safety
even though the walls, doors, ceiling and viewing windows are
designed to accept maximum radiation at a distance of three feet,
and do not allow X-ray or N-ray sources to be aimed at these
surfaces. In preferred embodiments of the present invention, the
robot positioners only allow the radiation source to be aimed
toward concrete bay floor 57, or airplane structure. This is
accomplished by programming the robotic movement throughout the
facility. Other than in the scan plan, which is discussed in
greater detail below, during the airplane inspection operation, the
radiation sources are non-operational. This is called the "Robotic
Approach." Both X-ray and N-ray sources are on systems or on/off
systems. The on/off systems may be energized at the beginning of
the scan plan inspection operation or calibration. Override of this
radiation protection system is accomplished for robot or source
maintenance purposes, and controlled by software code known
preferably to the first level supervisor and maintenance
personnel.
[0085] A method for design of a non-destructive inspection, testing
and evaluation system for airplane component having a precision
robotic system is provided. The dimensional and structural
requirements of a building are determined, and a preliminary design
for the building is made. The preliminary design for the building
is analyzed to identify any frequencies (earthquake zones) at which
such a building might resonate. For example, a technique such as
finite element frequency analysis may be employed. Based on the
results of the analysis, the preliminary design of the building may
be modified to correct any deficiencies.
[0086] The dimensional, structural, and functional requirements for
robots to be housed within the building are determined, and a
preliminary design of the robots is made. The preliminary design of
the robots is analyzed to identify any frequencies at which such
robots might resonate. Any interaction between the resonant
frequencies of the building and the resonant frequencies of the
robots are analyzed. Based on the results of the analysis, the
preliminary design of either or both of the building and the robots
may be modified to correct any deficiencies.
[0087] The dimensional, structural, and functional requirements of
any end effectors mounted on the robots are determined, and a
preliminary design of the end effectors is made. The preliminary
design of the end effectors is analyzed to identify any frequencies
at which such end effectors might resonate. Any interruption
between other elements, such as the building or the robots, is
analyzed. Based on the results of the analysis, the preliminary
design of any or all of the building, robots, or end effectors may
be modified to correct any deficiencies.
[0088] Another factor to be considered is the type of earthquake
region in which the facility is to be located. Different earthquake
regions may exhibit earthquakes having different characteristics,
for example earthquakes have vibration and motion of predominantly
a certain frequency range. This frequency range is determined for
the location at which the facility is to be located based on
geological data. The preliminary designs of the building, robots,
and end effectors are analyzed base on anticipated excitation from
earthquakes. Based on the results of the analysis, the preliminary
design of any or all of the building, robots, or end effectors may
be modified to correct any deficiencies.
[0089] When the preliminary designs of the buildings, robots, and
end effectors are completed, modeling of the entire system may be
performed to assure accuracy and repeatability of robot
positioning. Oscillatory excitation of the system components
resulting from robot motion and acceleration and deceleration may
be analyzed. Designs of the system components may be modified to
maximize desirable characteristics, such as accuracy and
repeatability of robot positioning, while minimizing undesirable
characteristics, such as unwanted oscillatory excitation of system
components.
[0090] FIG. 16 shows a plan view of an exemplar airplane 1600 that
is subject to inspection in the above-described robotic envelope as
part of fleet maintenance. To facilitate discussion, only certain
major components and sub-components are described below.
[0091] Airplane 1600 includes various component and sub-components.
As shown in FIG. 16, airplane 1600 includes components, such as a
left wing 1602, a right wing 2602, a left horizontal stabilator or
stabilizer 1604 (as those terms are interchangeably used in the
specification), a right horizontal stabilizer 2604, a left vertical
stabilizer 1606 and a right vertical stabilizer 2606. These
components further include sub-components. By way of example, left
wing 1602 includes sub-components such as a left wing tip 1602a, a
left aileron 1602b, a left flap 1602c. Similarly, right wing 1602
includes sub-components such as a right wing tip 2602a, a right
aileron 2602b, a right flap 2602c.
[0092] As another example, left horizontal stabilizer 1602 includes
sub-components, such as a left leading edge box 1604a and a left
aft box 1604b, and right horizontal stabilizer 2604 includes
sub-components, such as a right leading edge box 2604a and a right
aft box 2604b. Left and right vertical stabilizers 1606 and 2602
include sub-components such as, a left forward box 1606a, a left
torque box 1606b, a left aft box 1606c, a right forward box 2606a,
a right torque box 2606b, and a right aft box 2606c,
respectively.
[0093] Exemplar airplane 1600 resembles an F-15 aircraft, but
airplane 1600 could be any airplane or aircraft and may well
include a commercial airplane. Those skilled in the art will
appreciate that different airplanes include different components or
sub-components and even if different airplanes have the same
components or sub-components, they may have different component or
sub-component sizes. By way of example, although an F-15 has left
vertical stabilizer (e.g., denoted by reference numeral 1606 in
FIG. 16) and right vertical stabilizer ((e.g., reference numeral
2606 in FIG. 16), a commercial airplane has only a single vertical
stabilizer. The systems and methods of the present invention,
nevertheless, allow for effective automatic fleet inspection
despite these different component/sub-component configurations in
different types of airplanes.
[0094] NDI systems and processes of the present invention
preferably contain features to perform non-destructive inspection
and testing of intact airplanes or of components and/or
sub-components removed from an airplane. Such inventive systems and
methods include a database which contains electronic information
relating to at least one profile of a prototypical airplane or
component (a comparison standard), which is maintained in an
enclosure at constant environmental conditions (e.g., constant
temperature, humidity and pressure).
[0095] Although preferred embodiments of the inventive methods and
systems apply to fleet of airplanes, the present invention is not
so limited. Methods and systems of the present invention apply to
aircrafts and other types of in-flight vehicles (e.g., helicopters,
Unmanned Aerial Vehicles and spacecrafts). The terms "airplane" and
"aircraft" have been used interchangeably in the specification.
Furthermore, as the terms "airplane" and "aircraft" are used in the
specification, in addition to the in-flight vehicles mentioned
above, they include manned or unmanned vehicles capable of flight
by gaining support from air, and spacecrafts that are capable of
sub-orbital or orbital space flight.
[0096] FIG. 14 is a process flow diagram 1400 for maintaining an
airplane fleet, according to preferred embodiments of the present
invention. An airplane fleet includes a plurality of candidate
airplanes. In this embodiment, process 1400 begins with a step 1402
which includes developing a gold body database for a particular
airplane model and for each NDI system implemented to detect
defects. In other words, a gold body database is developed for a
particular airplane model using a particular NDI system (e.g., an
X-ray or an N-ray inspection system). By way of example, if an
X-ray and an N-ray inspection system are used to inspect candidate
airplanes of a particular model, then according to step 1402 a
first gold body database is developed for the X-ray inspection
system and a second gold body database is developed for the N-ray
inspection system. As will be explained later, the gold body
database developed in this step serves as a "reference database,"
during subsequent inspection or defect analysis steps. A more
detailed explanation of the development of a gold body database is
presented below in connection with a description of FIG. 15.
[0097] Next, a step 1404 includes inspecting, over a period of
time, a plurality of candidate airplanes of the particular model
using different types of NDI systems to perform one step selected
from a group consisting of generating a defect report using
different gold body databases associated with each NDI system, and
developing a baseline for each component or each sub-component in
the plurality of candidate airplanes that undergo inspection. In
other words, results (which preferably include a defect report
and/or a baseline) from the inspection of candidate airplanes using
a particular NDI system is compared to the gold body database
developed for that NDI system and for the particular model of the
candidate airplanes.
[0098] A step 1406 includes repairing or monitoring defects
detected on the plurality of candidate airplanes as will be
explained in greater detail in connection with FIGS. 23 and 24.
[0099] Preferably on a parallel track to step 1406, a step 1408 is
performed and includes conducting a trend analysis by analyzing
collective defect data obtained from the inspection of plurality of
candidate airplanes. Trend analysis includes at least one analysis
selected from a group consisting of applying Boolean logic rules,
tracking categories of defects found in a component or a
sub-component of the plurality of candidate airplanes through an
overlay of images obtained from one or more systems selected from a
group consisting of an X-ray system, an N-ray system and a laser UT
inspection system, tracking single site defect location or
multi-site defect locations, tracking defect dimension, tracking
growth of defect over a period of time, tracking low observable
coatings on plurality of candidate airplanes, tracking paint
deficiencies on plurality of candidate airplanes, applying Boolean
logic rules, and conducting statistical analysis. In preferred
embodiments, trend analysis of the present invention assigns a
defect detected to one of the candidate airplanes by associating
that defect with at least one item selected from a group consisting
of airplane manufacturer, airplane type, airplane model, airplane
tail number, airplane part noun, airplane part serial number, and
airplane component or sub-component location by number. More
details regarding trend analysis have been provided above and are
also provided below in a discussion relating to FIG. 22.
[0100] In a preferred embodiment, inventive process 1400 concludes
with a step 1410 which involves maintaining an airplane fleet by
performing predictive analysis, which uses results of trend
analysis that was conducted in step 1408. Predictive analysis
includes at least one analysis selected from a group consisting of
applying Boolean logic rules, projecting remaining life of
components or sub-components of said plurality of candidate
airplanes, projecting remaining life of said plurality of candidate
airplanes, projecting when said components or said sub-components
of said plurality of candidate airplanes should be removed from
service, projecting load limitations for said components or said
sub-components of said plurality of candidate airplanes, projecting
needed maintenance cycles for said plurality of candidate airplanes
and projecting spare parts inventory demand for said plurality of
candidate airplanes, projecting needed maintenance resources during
maintenance cycles for the plurality of candidate airplanes.
[0101] In certain embodiments of the present invention, Boolean
logic rules are applied to conduct trend analysis on a plurality of
candidate airplanes, which belong to an in-service airplane fleet.
By way of example, for candidate airplanes in an F-15C airplane
fleet, X-ray and N-ray robotic inspection systems and methods are
used to inspect a left and a right horizontal stabilizer's leading
edge box to detect defects. A sum of detected defects for each type
of defect (i.e., adhesive crack, blown core, cell corrosion, crack,
damaged core, moisture, skin corrosion, void, etc.) and their
respective locations on the X and Y coordinates from the origin are
recorded. Next, results by type and location of defects are
overlaid on a digital simulated image of the airplane's left and
right horizontal stabilizers, allowing a visual identification and
statistical analysis of trends for engineering analysis. In
preferred embodiments of the present invention, additional steps
follow the step of forming digital simulated image of the
airplane's component or sub-component. For example, a step of
monitoring airplane fleet condition and identifying fleet trends,
as they relate to defects, flaws and deficiencies present in a
region of a component or a sub-component, are carried out. As
another example, a step is carried out to automatically
electronically transmit data, digital image and statistical
analysis to engineering computer systems for engineering analysis.
In other embodiments of the present invention, certain data,
digital image and statistical analysis is sent to a governmental
regulatory body (e.g., Federal Aviation Administration) to meet
regulatory reporting requirements.
[0102] According to preferred embodiments of the present invention,
Boolean logic rules may also be used for conducting a predictive
analysis. In the above example, overlaying certain defect
properties on the digital simulated image and statistical analysis
of the left and right leading edge box allows for certain types of
predictive analysis, such as determination of need to ground fleet,
restrict fleets' operational threshold, and determination of
maintenance cycle for the fleet (e.g., every 6 months or 12
months), based on engineering analysis.
[0103] Those skilled in the art will appreciate that the above
example of F-15C is similarly applied to an F-35A fleet, where a
laser UT robotic inspection system is used for inspecting a right
wing leading edge of candidate airplanes in the F-35A airplane
fleet. Predictive analysis and trend analysis for the F-35A
airplane fleet is carried out in a manner that is very similar to
those described above for the F-15C airplane fleet.
[0104] FIG. 15 shows a process flow diagram for a process 1500,
according to a preferred embodiment of the present invention, for
developing a gold body database. Process 1500 includes a step 1502
which includes locating a reference airplane of a particular model
in space within a robotic envelope. By way of example, each model
and series airplane is located to a specific spot for a nose gear
and the main landing gear tires are aligned. The airplane
components/sub-components may be aligned to lines on the floor.
Other candidate airplanes of the same model and series, which are
subsequently inspected, will also use those lines on the floor for
rough positioning. The airplane is then jacked into position using
jacks 205 (as shown in FIG. 3), taking the load off of the tires
and actuators. Thus, the airplane becomes fixed in position and can
no longer move due to change in tire pressure attributed to
environmental changes or loss of hydraulic pressure in the
actuators. Edges which define the boundary of the plane are taught
to one or more robots used in one or more NDI inspection
systems.
[0105] Next, a step 1504 includes locating a component or a
sub-component in space within the robotic envelope such that during
a subsequent inspection of candidate airplanes of the particular
model, a corresponding component or sub-component in candidate
airplanes is automatically located in space using a robot. In this
step, at least two or more edges of a component or a sub-component
are preferably taught to each of the robots associated with an NDI
system.
[0106] A step 1506 includes teaching a scan plan for the component
of the sub-component located in space. The scan plan in this step
is taught for each NDI system that is subsequently implemented to
detect defects in candidate airplanes. In this manner, process 1500
is carried out for each NDI system that is implemented for defect
detection, which in turn is carried out for effective airplane
fleet management.
[0107] FIG. 17 shows an exemplar scan plan 1700 developed for a
right leading edge box (e.g., leading edge box 2604a of FIG. 16) of
a right horizontal stabilizer (e.g., horizontal stabilizer 2604 of
FIG. 16) using MNRS. Scan plan 1700 is represented in FIG. 17 in
graphical form, i.e., displacement of an MNRS robot along a Y-axis
1704 versus displacement of the MNRS robot along an X-axis 1702. In
step 1506 of FIG. 15, scan plan like the one shown in FIG. 17 is
taught to an MNRS robot and the taught information, a zero-zero
coordinate in the x-y plane 1752 and registration points 1754, 1756
and 1758, are is saved as part of the gold body database. Lines
1706 represent a path of movement from one registration point 1754
to another registration point 1756 and to yet another registration
point 1758 that is traced by the MNRS robot, as it scans the right
leading edge box during inspection. Those skilled in the art will
appreciate that scan plan 1700 is an exemplar graphical
representation of the MNRS robot's plan of movement during a
subsequent inspection process and that a scan plan is created for
each or critical components and/or sub-components of a candidate
airplane.
[0108] FIG. 18 shows another exemplar scan plan 1800 developed for
a right leading edge box (e.g., leading edge box 2604a of FIG. 16)
of a right horizontal stabilizer (e.g., horizontal stabilizer 2604
of FIG. 16) using MXRS, as opposed to using MNRS as described in
connection with FIG. 17. Like scan plan 1700, scan plan 1800 also
is represented in FIG. 18 in a graphical form, i.e., displacement
of a MXRS robot along a Y-axis 1804 versus displacement of the MXRS
robot along an X-axis 1802. Scan plan 1800 is also taught to the
MXRS robot and is saved as part of the gold body database. Lines
1806 represent a path of movement traced by the MXRS robot, as it
scans the right leading edge box during inspection.
[0109] Scan plans are different for each robotic imaging method
such as for N-ray, X-ray or laser UT because of the field of view
and the area of interest due to the type of airplane structure.
Nonetheless, the X and Y-axis coordinates on the
component/sub-component or panel remains the same. As will be
explained later, this allows the results of each inspection method
(e.g., X-ray, N-ray, Reverse Geometry and laser UT) to be
identified on a master layout, allows overlaying results of the
inspections to identify multi-site damage and allows downloading
the results of each airplane inspected to overlay on the same
component, sub-component or panel for determining trend analysis
and model airplane fleet condition.
[0110] Use of scan plans facilitates automatic inspection of
airplane fleets. By way of example, once the whole airplane has
been taught to the system of the present invention, the scan plans
of each NDI method can be applied in part or whole on candidate
airplanes to carry out inspection.
[0111] Inspection of a component or a sub-component using a
particular NDI system produces, among other things, a defect report
for that component or sub-component and for that particular NDI
system. A defect report contains at least one item selected from a
group consisting of category of defect, defect location and defect
dimensions. Defect location is preferably a location of defect in
(x, y) coordinates of the inspected component or sub-component. A
defect map may be formed for a component or sub-component by
aggregating one or more defect locations. The defect map so formed
is associated with the particular NDI system used for defect
detection.
[0112] Two or more defect maps, each generated from a different NDI
system, may overlay on a single map to produce an integrated map,
which serves as a historical record for that component or
sub-component. FIG. 19 shows an integrated defect map 1900 produced
from overlaying two defect maps produced by inspection of a right
leading edge box of a right horizontal stabilizer using MXRS and
MNRS. Integrated map 1900 is a graphical representation as it shows
location of defects by referring to their locations on the X-axis
and Y-axis. As shown in FIG. 19, integrated map 1900 has defined
thereon shape 1906 of the inspected sub-component, i.e., a right
leading edge box of a right horizontal stabilizer Inside shape
1906, one or more defects are presented. Integrated map 1900
preferably also presents a legend to convey the meaning of one or
more symbols or letters placed at a defect location. By way of
example, at one defect location 1908, which is labeled "M" and "m"
and has coordinates of about (-5,-5), both MNRS and MXRS
inspections convey that moisture is present at that location.
[0113] FIG. 20 shows a volumetric X-ray or N-ray imaging
configuration 2000, which may be used to provide a baseline image
obtained during component and/or sub-component inspection. In this
configuration, a radiation imaging source 2004, which can be an
X-ray imaging source or an N-ray imaging source, is used to inspect
a sub-component 2002. Radiation source 2004 is positioned on one
side of sub-component 2002 such that a beam of radiation is
incident upon the sub-component during an imaging process. A
radiation source detector 2006 disposed on the other side of
sub-component 2002 detects the radiation that is transmitted
through the sub-component. During a volumetric measurement process
to create a three-dimensional image of a defect, radiation source
2004 articulates around a tool point 2008.
[0114] Volumetric measurement, according to one embodiment of the
present invention, is accomplished by precise robotic articulation.
Precise robotic articulation is accomplished by having a robot
rotate 360 degrees in a circle about a tool point, causing both
radiation source 2004 and detector 2006 to similarly rotate.
[0115] Certain embodiments of the present invention include two
dimensional ("2D") and three dimensional ("3D") data capture and
imaging inspection methods and technologies. Data identifying the
size of the defect or discrepancy is captured in the X-axis, Y-axis
and Z-axis. Analog film and digital images capture and show the
defect or discrepancy in X and Y coordinates. Once the defect or
discrepancy is identified the system is capable of articulating in
a circle about the defect tool point or object capturing an image
of the tool point or object at a minimum of 8 imaging stations or
at least every 45 degrees on the circle. 3D images may be
reconstructed by articulating in a circle about the defect tool
point or object capturing an image of the tool point or object at a
minimum of 16 imaging stations or at least every 22.5 degrees on
the circle. Adjacent imaging stations images are then super imposed
to provide a 3D image. Computer generated reconstruction of
multiple images is used to generate a laminography image. The
defect or discrepancy's location within a component is identified
by X-axis, Y-axis and Z-axis distance from the component's X and Y
origin and the layers within which it resides between the
component's innermost layer and outermost layer. The data, film and
images showing the defect's and discrepancy's size and location
within the component is recorded with the component's part number
and serial number, and the component is recorded at the time of the
inspection with the airplane's tail number. The component may be
used on multiple airplanes, during their life cycle, by being
disassembled from the airplane, repaired or refurbished, and then
placed into a rotational spares inventory for use on any airplane
undergoing maintenance and repair.
[0116] Display of images is accomplished utilizing 2D and 3D front
or rear projection screens, displays and monitors. The viewer may
wear active shudder glasses or passive Polaroid glasses when
viewing projection screens, display and monitors requiring these
eyewear devices. X-ray and N-ray scan plans are modified to
accomplish this task. These methods may be utilized when capturing
and viewing real time or offset images, such as volumetric
measurement that detects and provides data and image capture of the
length, width and depth of a defect or discrepancy in structural
material. The data and image capturing and viewing methods are
commonly used in the inspection of airplane components comprised of
multi-layered metal and composite structural material. This method
identifies defect and discrepancy size and location to monitor
component maintenance, assist implementation of pre-repair
procedures and repair technologies, and validate post repair
procedures.
[0117] FIG. 21A shows a comparison between two components defect
maps, one map for a left and another map for a right horizontal
stabilizer (e.g., map for left horizontal stabilizer 1604
juxtaposed to a map for right horizontal stabilizer 2604 shown in
FIG. 16). The component defect map shows a left region 2102 in a
left leading edge of the left horizontal stabilizer and a
corresponding right region 2104 in a right leading edge of the
right horizontal stabilizer. Left region 2102 includes moisture
defects, which are not found in the corresponding right region
2104. While not wishing to be bound by theory, presence of such
defects in one region and absence of them in a second region convey
that they are manufacturing defects. As a result, defect analysis
of the present invention provides a feed-back loop to the
manufacturing process regarding the amount and types of defects
being introduced during manufacturing, and the repair process will
be different.
[0118] FIG. 21A shows, among other things, results of mobile
airplane inspection, and the comparison of findings of left and
right horizontal stabilizer components. It is noteworthy that
defect locations are not similar in comparison. According to
preferred embodiments of the present invention, engineering
disposition investigates and determines why certain defects, such
as fatigue, defects from use of improper materials, and defects
resulting from manufacturing and assembly process, exist or exist
in one region, but not in another corresponding region.
[0119] FIG. 21B is a tabular representation of summary of defects
found in a right horizontal stabilizer. The summary of defects is
broken down into sub-components, having those that are disposed on
the left side juxtaposed with those that are on the corresponding
right side of the airplane. Furthermore, for each sub-component,
number of defects that belong to a particular defect category
(e.g., adhesive crack, blown core, cell corrosion, crack, damaged
core, moisture, skin corrosion and void) are also tracked and
summarized. Further still, summary of defects also informs
regarding the number of defects found by MXRS inspection (shown in
FIG. 21B as "MX") and by MNRS inspection (shown in FIG. 21B as
"MN"). As an example, FIG. 21B shows that the number of corroded
cells found in the left aft box using MXRS is 13, and using MNRS is
3. It is believed that a significant difference in the results
between MXRS and MNRS inspection allows for various possible
conclusions, all of which inform the manufacturing and repair
process.
[0120] FIG. 22 presents an exemplar trend analysis of 50 airplanes
of an airplane fleet. All the various components and sub-components
therewithin are presented along a left column, and in the remaining
columns an analysis is presented for ten, twenty, thirty, forty and
fifty airplanes. As an example, a trend analysis for forty
airplanes identifies the defect components. With regard to wing
components, trend analysis shows that 30% of the flaps, 85% of
ailerons and 43.8% of the wing tips are defective. Similarly for
horizontal stabilizers, trend analysis shows 66.3% of aft boxes and
75% of leading edge boxes are defective. For vertical stabilizers,
trend analysis shows that 50% of forward boxes, 30% of torque
boxes, and 55% of aft boxes are defective. As mentioned above, for
each component and/or sub-component, FIG. 21B provides the types of
defects found in the components/sub-components. With regard to the
aft and leading edge boxes of a horizontal stabilizer, FIG. 21B
shows that defects are primarily moisture sites and skin
corrosion.
[0121] As mentioned before, trend analysis allows monitoring
airplane fleet condition and identifying fleet trends, as they
relate to defects, flaws and deficiencies present in a region of a
component or a sub-component. Such analysis is based on developing
results by type and location of defects. Where an airplane's
horizontal stabilizers are the component of concern, it has been
explained that these results may be overlaid on a digital simulated
image of the left and right horizontal stabilizers, allowing a
visual identification and statistical analysis of trends for
engineering analysis. Boolean logic rules, which may be applied on
type of defect, defect severity, and defect frequency (a
statistically monitored condition), facilitate prediction or, in
the alternative, projection of maintenance activities to
effectively manage an airplane fleet. Maintenance activities of the
present invention include, but are not limited to, grounding an
airplane fleet, restrict a fleet's operational thresholds that
govern flight loads, and electronically trigger maintenance
planning, execution, and reporting. In other embodiments of the
present invention, Boolean logic rules determine a recommended
inspection frequency to monitor the fleet's defect condition (e.g.,
defect growth), and/or maintenance or repair treatment plan.
[0122] The following Boolean logic algorithm is based on the
results of trend analysis and represents an example of maintenance
and treatment plan implemented according to the present invention
for an in-service F-15C aircraft fleet (referred to as "F-15C
Fleet" below):
[0123] If F-15C Fleet LHS SC>or =5, and if ML>8%, then F-15C
Fleet LHS TCTO XI and NI=12 and ALC-I99061-02; and if ML<8%,
then F-15C Aircraft LHS ALC-R890444-01; and if ML>8%, then F-15C
Aircraft LHS ALC-RR890526-01; and if ML>10%, then F-15C Aircraft
T=80%; and then F-15C Fleet XI and NI=60 and ALC-M890538-00;
[0124] If F-15C Fleet LHS SC<5, if ML<8%, then F-15C Aircraft
ALC-R890444-01 and if ML>8%, then F-15C Aircraft LHS
ALC-RR890526-01, and if ML>10%, then F-15C Aircraft T=80%, and
then F-15C Fleet XI and NI=60 and ALC-M890538-00.
[0125] According to this algorithm, if skin corrosion (which is
denoted by "SC" above) is detected in a left horizontal stabilizer
("LHS") in 10% or more of 50 F-15C aircrafts ("F-15C aircrafts")
belonging to the in-service F-15C aircraft fleet, then different
recommended actions are possible for the airplane fleet and a
particular airplane, depending on results of different defect
measurements. If material loss ("ML") is greater than 8% for the
entire fleet, then an inspection by X-ray inspection ("XI") and
N-ray inspection ("NI") for the entire F-15C aircraft fleet is
scheduled to occur within 12 months under a Time Compliant
Technical Order ("TCTO"), and pursuant to treatment plan
ALC-I99061-02. If a material loss is less than 8%, however, then
for the F-15C aircraft, which satisfies the material loss
condition, an instruction is provided to repair the moisture
intrusion entry path in the left horizontal stabilizer pursuant to
ALC-R890444-01.
[0126] For a particular aircraft, which suffers from a material
loss that is greater than 8%, then left horizontal stabilizer is
scheduled for repair and replacement pursuant to treatment plan
ALC-RR890526-01. Furthermore, if the material loss for that
aircraft measures greater than 10%, an instruction is provided to
reduce in-flight operational threshold thrust ("T") of that
aircraft to 80% of maximum performance until F-15C aircraft
completion of left horizontal stabilizer's replacement. For this
material loss condition, after left horizontal stabilizer repair
pursuant to treatment plan ALC-R890444-01 or replacement and repair
pursuant to treatment plan ALC-RR890526-01, as the case may be
within the twelve-month maintenance cycle, an inspection by X-ray
inspection ("XI") and N-ray inspection ("NI") for the entire F-15C
aircraft fleet is scheduled to occur thereafter in sixty months
pursuant to treatment plan ALC-M890538-00.
[0127] In the same example, if skin corrosion is detected in the
left horizontal stabilizer in less than 10% of 50 aircrafts of the
F-15C aircraft fleet, and if material loss for the F-15C aircraft
fleet is less than 8%, then an instruction is provided to repair
the moisture intrusion entry path in the left horizontal stabilizer
of each detected F-15C aircraft pursuant to ALC-R890444-01. For a
particular F-15C aircraft, which suffers from a material loss that
is greater than 8%, then left horizontal stabilizer is scheduled
for repair and replacement pursuant to treatment plan
ALC-RR890526-01. Furthermore, if the material loss for that
aircraft measures greater than 10%, an instruction is provided to
reduce in-flight operational threshold thrust ("T") of that
aircraft to 80% of maximum performance until completion of left
horizontal stabilizer's replacement. For this material loss
condition, after left horizontal stabilizer repair pursuant to
treatment plan ALC-R890444-01 or replacement and repair pursuant to
treatment plan ALC-RR890526-01, as the case may be within the
twelve-month maintenance cycle, an inspection by X-ray inspection
("XI") and N-ray inspection ("NI") for the entire F-15C aircraft
fleet is scheduled to occur thereafter in sixty months pursuant to
treatment plan ALC-M890538-00.
[0128] Treatment plans ALC-I99061-02, ALC-R890444-01,
ALC-RR890526-01, and ALC-M890538-00 consist of digital code-driven
tables. Such tables typically consist of airplane repair station
procedures and processes necessary for inspection, maintenance, and
repair. Furthermore, such tables may also contain digital
sub-tables of required and interrelated repair station resources.
Examples of interrelated repair station resources include, but are
not limited to, facilities, equipment, manpower, man-hours,
service-time, and direct and indirect costs and the utilization
sequence of same in the inspection, maintenance, and repair
process.
[0129] By way of example, a table-driven procedure for
ALC-RR890526-01, which may be automatically selected when
implementing Boolean logic rules, includes: (a) identifying repair
procedures and/or develop new or additional procedures; (b)
identifying direct and indirect materials needed for repair; (c)
identifying any special tooling and equipment needed for the
repair; (d) identifying or determine mechanic, technician, and
specialist repair team certifications and training needs to satisfy
repair procedures; (e) scheduling prototype development on repair
procedures; (f) identifying or develop technical data for the
processes; (g) identifying amount of spares available in supply;
(h) inspecting spares as in Example 1A for defects; (i) repairing
deficient spares in preparation as a replacement part; (j)
Re-inspecting all repaired spares for proper repair; (k)
identifying or determine repair timeline for scheduling of
resources; (l) scheduling facility, equipment, inventory,
materials, and human resources required; (m) scheduling airplane
fleet for induction into repair at repair station; (n) projecting
repair budget; (o) inducting the airplane fleet for horizontal
stabilizer repair; (p) repairing dismantled left or right
horizontal stabilizer; (q) inspecting repaired left or right
horizontal stabilizer for defects before placing it into spares
inventory.
[0130] FIG. 23A shows a process 2300, according to a preferred
embodiment of the present invention, for airplane inspection which
requires removal of a defective component or sub-component. In this
embodiment, inventive process 2300 begins with a step 2302. Step
2302 includes locating a candidate airplane, which will be subject
to inspection by one or more NDI systems, in space within a robotic
envelope. Next, a step 2304 includes locating a component or a
sub-component of the candidate airplane in space within the robotic
envelope.
[0131] Once the airplane and the component or the sub-component is
located in space, one or more NDI systems are in position to
commence a scanning step. A step 2306 includes scanning the
component or the sub-component according a scan plan developed for
that component or that sub-component. As mentioned above, each
robot associated with an NDI system is taught a scan plan (e.g.,
step 1506 of FIG. 15) during a previous process of forming a gold
body database.
[0132] A step 2308 includes identifying defects to generate a
defect report (e.g., presenting category, location and dimensions
of each defect) for the component or the sub-component, and/or to
develop a baseline for the component or the sub-component. In a
following step 2310 it is inquired whether there are any defects
which need to be repaired. As mentioned before, defects are
preferably evaluated against a predetermined accept/reject criteria
to determine corrective maintenance and repair actions
[0133] If it is determined that none of the defects identified need
to be repaired, then process 2300 moves to a step 2312, which
includes monitoring the defects over a period of time when
inspections such as the ones described above are carried out.
Monitoring includes tracking defects growth in length, width and
depth.
[0134] If, however, it is determined that one or more defects need
to be repaired, then process 2300 moves to a step 2314, which
includes removing from the airplane the component or the
sub-component that needs to be repaired. After step 2314, various
steps involved in process 2300 are presented in FIG. 23B.
[0135] According to FIG. 23B, a step 2316 follows step 2314 (of
FIG. 23A) and includes repairing the component or the sub-component
to remedy the defect(s). Next, a step 2318 includes developing an
"off-the-airplane" scan pan for the repaired component or the
repaired sub-component and storing on a database the
off-the-airplane scan plan such that it is associated with a serial
number of the repaired component or the repaired sub-component. An
"off-the-airplane" scan plan looks similar to the scan plans shown
in FIGS. 17 and 18. However, as the name suggests, an
"off-the-airplane" scan plan is developed when a component or a
sub-component is off the airplane. Then, a step 2320 is carried out
and includes inspecting the component or the sub-component to
determine if the defect was repaired properly.
[0136] A step 2322 inquires whether the defect was repaired
properly. If it is determined that the defect was not repaired
properly, then process 2300 goes back to step 2316, where repairs
are carried out again. Steps 2318, 2320 and 2322 follow the repair
step of 2316. In this manner, steps 2316, 2318, 2320 and 2322 may
be carried out, according to a loop shown in FIG. 23B, until the
defects are repaired properly.
[0137] If, however, it is determined that the defect was repaired
properly, then process 2300 moves forward to a step 2324, where
another inquiry is made. In step 2324, it is inquired whether the
properly repaired component or the properly repaired sub-component
should be installed on the airplane at this point. In other words,
step 2324 inquires whether another component or sub-component
should be installed on the candidate airplane, instead of
installing the repaired component or the repaired sub-component.
Such an inquiry may be made for a variety of reasons. By way of
example, if the repair process is long and time-consuming, another
component or sub-component from inventory is installed on the
candidate airplane so that the candidate airplane is back to being
functional in short order.
[0138] If it is determined in step 2324 that that the repaired
component or sub-component should be installed at that point on the
candidate airplane, then process 2300 moves to a step 2332, which
requires installing the repaired component or repaired
sub-component on the airplane. Next, in a step 2334 the newly
developed scan plan for the repaired component or the repaired
sub-component is incorporated into the overall scan plan for the
airplane. In preferred embodiments of the present invention, step
2334 is carried out by assigning a scan plan developed for the
repaired component or repaired sub-component to the tail number of
a candidate airplane.
[0139] If it is determined in step 2324 that that the repaired
component or sub-component should not be installed at that point on
the candidate airplane, then process 2300 moves to a step 2326,
which requires holding the repaired component or the repaired
sub-component as inventory. Next, in a step 2328 the repaired
component or the repaired sub-component is installed on another
airplane, which is different than the airplane from which the
component or the sub-component was removed, as mentioned in step
2314 of FIG. 23A.
[0140] A step 2330 includes incorporating the newly developed scan
plan for the repaired component or the repaired sub-component in
the overall scan plan for the airplane in which the repaired
component or the repaired sub-component is installed. As a result,
for subsequent inspection of the airplane, there exists an updated
gold body database to effectively identify defects.
[0141] FIG. 24A shows a process flow diagram for a process 2400,
according to one preferred embodiment of the present invention, for
an airplane inspection, which does not require removal of a
defective component or sub-component.
[0142] Process 2400 preferably begins with a step 2402 which
includes locating a candidate airplane, which will be subject to
inspection by one or more NDI systems, in space within a robotic
envelope. In step 2402, an airplane offset is arrived at by
comparing a current location of the airplane to a reference
location of the airplane. The reference airplane location is
preferably stored as part of the airplane's gold body database. The
offset preferably represents a difference between a current
location of the airplane to the reference location of the
airplane.
[0143] Next, a step 2404 includes locating a component or a
sub-component of the candidate airplane in space within the robotic
envelope. Like step 2402, step 2404 also arrives at an offset.
However, in step 2404 the offset may be called a "component offset"
or a "sub-component offset," as it results from the comparison
between the current location of the component or the sub-component
and the reference location of the component or the sub-component
stored in the gold body database.
[0144] A step 2406 is then carried out to scan the component or the
sub-component according to a scan plan developed for that component
or that sub-component, such that the scan plan compensates for the
component offset or the sub-component offset. In other words, the
scan plan is initiated when the reference points (i.e., the
zero-zero coordinates) of the component or the sub-components
located in space are established from the component or the
sub-component offsets.
[0145] Next, a step 2408 includes identifying defects to generate a
defect report (e.g., presenting category, location and dimensions
of each defect) for the component or the sub-component, and/or to
develop a baseline for the component or the sub-component. The
defect report and/or baseline obtained from step 2408 is archived
in step 2410 so that at a later time, it is possible to conduct a
trend analysis on data collected from a plurality of airplanes, or
conduct a base line comparison for the component or the
sub-component. After step 2408, it is inquired whether there are
any defects which need to be repaired.
[0146] If it is determined that none of the defects identified need
to be repaired, then process 2400 moves to a step 2414, which
includes monitoring the defects over a period of time when
inspections such as the ones described above are carried out.
[0147] If, however, it is determined that one or more defects need
to be repaired, then process 2400 moves to a step 2416 (shown in
FIG. 24B), which includes repairing the component or the
sub-component to remedy the defect(s). Next, a step 2418 is carried
out and includes inspecting the component or the sub-component to
determine if the defect was repaired properly.
[0148] A step 2420 inquires whether the defect was repaired
properly. If it is determined that the defect was not repaired
properly, then process 2300 goes back to step 2416, where repairs
are carried out again. Steps 2418 and 2420 follow the repair step
of 2416. In this manner, steps 2416, 2418 and 232 may be carried
out, according to a loop shown in FIG. 24B, until the defect(s) are
repaired properly.
[0149] If, however, it is determined that the defect was repaired
properly, then process 2400 may conclude at a step 2422 which
includes storing on a database results of the scan plan of the
airplane's overall scan plan. In preferred embodiments of the
present invention, step 2422 is carried out by assigning the scan
plan to a tail number of the airplane.
[0150] In certain embodiment of the present invention, once a
repaired component passes post inspection (i.e., the inquiry in
steps 2322 (of FIGS. 23) and 2420 (of FIG. 24) are answered in the
affirmative), archival data and images are assigned and recorded to
that specific component by the component's part and serial numbers,
and by the tail number of the airplane on which it is installed.
Cradle to grave identification of all inspected components, by
intact airplane systems or component systems, are archived and
indexed by tail number, part number and serial number. Spare parts
are inspected prior to installation and eventually identified and
indexed to specific airplane tail number.
[0151] It is noteworthy that candidate airplanes, undergoing
inspection, are not absolutely required to be jacked in place for
stabilization. In such instances, the airplane may be located
within the robotic envelope to the line markings on the floor plus
or minus eight inches. The robot then seeks to locate the vision
edges on the airplane. Once located, the robot automatically
recognizes where the taught airplane was in reference and where
follow-on production airplane is located. As explained above, this
is called an offset and is transparent to system operators. Scan
plan accuracy is preferably about 0.120 thousands of an inch on all
production airplanes. Given that no two airplanes are exactly the
same, a system operator can manually align the robot by joystick
control to the beginning zero-zero coordinates on each and every
component or sub-component, allowing about 0.120 thousands of
accuracy of scan for each component or each sub-component from
airplane to airplane. For precise measurement and evaluation of
defects, manual alignment can also be accomplished by aligning to a
particular defect.
[0152] This description of the disclosed aspects of the present
invention is provided to enable any person skilled in the art to
make or use the present invention. Various modifications to these
aspects will be readily apparent to those skilled in the art, and
the generic principles defined herein may be applied to other
aspects without departing from the spirit or scope of the
invention. Moreover, having thus described the invention, it should
be apparent that numerous structural modifications and adaptations
may be resorted to without departing from the scope and fair
meaning of various embodiments of the instant invention as set
forth hereinabove and as described herein below by the claims.
* * * * *