BACKGROUND OF THE INVENTION
The subject matter disclosed herein relates generally to nondestructive
testing systems, and more particularly, to ultrasonic tomography systems for
nondestructive testing.
Many industrial inspection applications rely on imaging techniques to *
determine the quality of industrial parts, such as pipes, pipe arrays, and so forth. For
example, such inspection techniques may be utilized to determine the presence and/or |
^ P location of one or more defects in an object, such as the presence of cracks, cavities,
or other imperfections. One imaging modality that may be utilized to inspect objects ;
for the presence of defects is ultrasonic tomography. Ultrasonic tomography is an
imaging modality that employs ultrasound waves to probe the acoustic properties of
the object of interest and to produce a corresponding image of the object, including
any detectable defects. Generation of sound wave pulses and the detection of
returning echoes is typically accomplished via transducers located in a transducer
probe. Transducer probes typically include electromechanical elements that are I
capable of converting electrical energy into mechanical energy for transmission and {
that also are capable of converting mechanical energy back into electrical energy for f
receiving purposes. I
Unfortunately, in some applications, the size of the defects relative to the
^ F size of the inspected object is relatively small, which makes it difficult to detect their {
presence in the reconstructed image of the inspected object. Furthermore, in many
instances, multiple small defects may be spaced closely together, and while the
combined area of the defects may be detectable via ultrasonic inspection, the size of
each individual defect may be below the resolution of the system. Since the ability to
identify defects present in the object is largely a function of the quality and resolution
of the resulting image of the object, there exists a need for improved systems that
overcome the aforementioned drawbacks.
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BRIEF DESCRIPTION OF THE INVENTION
Certain embodiments commensurate in scope with the originally claimed {
invention are summarized below. These embodiments are not intended to limit the j
scope of the claimed invention, but rather these embodiments are intended only to provide a brief summary of possible forms of the invention. Indeed, the invention
may encompass a variety of forms that may be similar to or different from the j
embodiments set forth below. In a first embodiment, a system includes a segmented transducer probe I
i
having a plurality of transducer segments adapted to transmit ultrasonic excitation
^r signals into a test specimen and to receive echo signals resulting from the interaction j
of the ultrasonic excitation signals and the test specimen. The system also includes a I
processing system adapted to receive data from the segmented transducer probe that i
x
corresponds to the received echo signals and to utilize tomographic reconstruction j
methods to reconstruct an image corresponding to at least one volumetric slice of the test specimen.
In a second embodiment, a method includes delivering a rotatable, non- I
axial-symmetric sound field to a test specimen and receiving echo signals resulting jj
from an interaction of the rotatable, non-axial-symmetric sound field and the test j
specimen. The method also includes rotating the non-axial-symmetric sound field j
incrementally, delivering the rotated sound field to the test specimen and receiving '
^ ^ further echo signals resulting from an interaction of the incrementally rotated, non-
^ axial-symmetric sound field and the test specimen. The method further also includes
utilizing the received echo signals and tomographic reconstruction methods to
reconstruct an image corresponding to at least one volumetric slice of the test
specimen.
In a third embodiment, a method includes delivering a rotatable, non-axialsymmetric
sound field to a test specimen under an entrance angle of approximately
zero degrees. 1
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In a fourth embodiment, a method includes delivering a rotatable, non- j
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axial-symmetric sound field to a test specimen under a variable entrance angle. The j
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sound field may be delivered to the test specimen throughout multiple different j
entrance angles. In certain embodiments, the entrance angle is controlled by phased I
array techniques. j
In a fifth embodiment, a method includes delivering a rotatable, non-axial- I
symmetric sound field exhibiting a two-fold, three fold, four fold, or n-fold rotational j
symmetry to a test specimen. In one embodiment, a highly unsymmetrical two-fold j
symmetry having an aspect ratio of approximately 1:2 or greater than approximately j
£ | 1:2 may be delivered. For example, an aspect ratio of approximately 1:5 or higher may be utilized. In a sixth embodiment, a device includes a segmented transducer probe. |
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The transducer probe includes an array of transducer segments arranged such that the j
array exhibits a four-fold, five-fold, six-fold, or n-fold rotational symmetry, wherein j
an n-fold symmetry with n equal to or higher than 8 may be utilized. In some f
embodiments, n is equal to or greater than approximately 16, for example, equal to or greater than approximately 32. In certain embodiments, n may be a multiple of two or j
four. The transducer probe includes a plurality of opposite pairs of transducer S
segments. These pairs may include one, two, three, four or more adjacent transducer f
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elements. In certain embodiments, the transducer segments may be substantially the j
same shape and size. The opposite pairs of transducer segments are adapted to be
| A activated to generate a rotatable, non-axial-symmetric sound field.
In a seventh embodiment, a device includes a circular segmented transducer
probe. The transducer probe includes an array of transducer segments circularly i
disposed about a rotation center point of the circular segmented transducer probe, the I
array having a plurality of opposite pairs of two, four, six, or any other suitable I
quantity of transducer segments. The opposite pairs of transducer segments are
adapted to be activated to generate a rotatable, non-axial-symmetric sound field. In {
some embodiments, the transducer segments are circularly disposed about an inner I
diameter of the circular segmented transducer probe.
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In an eighth embodiment, a segmented transducer probe may be utilized for
generating a rotatable, non-axial-symmetric sound field. The transducer probe |
includes an array of transducer segments arranged such that the array exhibits a two- j
fold, three fold, four fold, or ,n-fold rotational symmetry. For example, a two-fold j
symmetry may be exhibited in one embodiment. The transducer probe includes a
plurality of opposite pairs of two, four, six, or any other suitable quantity of j
transducer segments. The opposite pairs of transducer segments are adapted to be
activated to generate a rotatable, non-axial-symmetric sound field. In one i
embodiment, the transducer probe is circularly segmented, and the transducer I
segments are circularly disposed about an inner diameter of the circular segmented j
# transducer probe. j
BRIEF DESCRIPTION OF THE DRAWINGS
1
These and other features, aspects, and advantages of the present invention t
will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts '
throughout the drawings, wherein:
FIG. 1 is a schematic diagram of an embodiment of an ultrasonic testing j
system utilizing a segmented probe; j
FIG. 2 is a block diagram depicting an embodiment of a control and
processing system that can be used with the segmented probe of FIG. 1;
FIG. 3 depicts an embodiment of a segmented transducer probe mat can be
employed in the ultrasonic testing system of FIG. 1; j
FIG. 4 depicts an embodiment of a rotatable non-axial-symmetric sound ;
field that can be generated with the segmented transducer probe of FIG. 3;
FIG. 5 is a flow chart of an embodiment of a method that can be employed
to generate a reconstructed image of a test specimen by using the segmented
transducer probe of FIG. 3;
5 FIG. 6 is a schematic diagram depicting an embodiment of a sound field j
rotation about a defect in a test specimen at a first probe location; |
|
FIG. 7 depicts an embodiment of a matrix that can be generated with the |
sound field of FIG. 6; f
FIG. 8 is a schematic diagram depicting an embodiment of a sound field
rotation about a defect in a test specimen at a second probe location;
FIG. 9 depicts an embodiment of a matrix that can be generated with the |.
sound field of FIG. 8; ;
^ ^ FIG. 10 is a schematic diagram depicting an embodiment of a sound field J
rotation about a defect in a test specimen at a third probe location; and
f-
FIG. 11 depicts an embodiment of a matrix that can be generated with the {
sound field of FIG. 10. j
DETAILED DESCRIPTION OF THE INVENTION |
One or more specific embodiments of the present invention will be described below. In an effort to provide a concise description of these embodiments, j
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all features of an actual implementation may not be described in the specification. It »
j should be appreciated that in the development of any such actual implementation, as j in any engineering or design project, numerous implementation-specific decisions r
^ 6 must be made to achieve the developers' specific goals, such as compliance with I
system-related and business-related constraints, which may vary from one
implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be {
a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.
j When introducing elements of various embodiments of the present
I invention, the articles "a," "an," "the," and "said" are intended to mean that there are
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j one or more of the elements. The terms "comprising," "including," and "having" are [
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intended to be inclusive and mean that there may be additional elements other than the listed elements. i
The disclosed embodiments are directed to ultrasonic tomography
inspection systems capable of non-destructively probing a test specimen with
ultrasonic energy to identify the presence and/or quantity of defects present inside the
test specimen. To that end, disclosed embodiments include segmented transducer
probes capable of generating a rotatable, non-axial-symmetric sound field that can be
directed into the test specimen. For example, in one embodiment, a circular !
segmented transducer probe may include opposite pairs of transducer segments, and j
J B I each transducer segment and the segment with which it is paired may transmit and I
receive signals concurrently. The resulting sound field may be substantially elliptical.
By activating the adjacent opposite pairs, quadruples, or other suitable combination of j
transducers one after the other, the substantially elliptical sound field is rotated. The j
angle of rotation is dependent on the segmentation of the transducer. For each angle of rotation, the probe receives echo signals resulting from the interaction of the sound
field with the test specimen and communicate data representing the echo signals to a
processing system. The processing system is capable of employing a tomographic j
reconstruction method to the collected echo signals and to reconstruct a series of f
images corresponding to volumetric slices of the test specimen and is further capable
of combining those images to reconstruct a volumetric representation of the test I
specimen. That is, the processing system may utilize any of a variety of known
tomographic reconstruction methods to reconstruct the volumetric representations.
^F For example, the processing system may utilize the echo signals to perform an
algorithm that emulates the acquisition process of the echo signals in reverse along
circular arcs. The reconstructed volumetric representation achieved through the
disclosed embodiments may offer advantages over those obtained with existing I
ultrasonic tomography inspection systems since the rotatable, non-axial-symmetric
sound field may increase the resolution of the reconstructed slices of the test
specimen, thereby better enabling identification of defects. Turning now to the drawings, FIG. 1 is a schematic diagram depicting an
embodiment of a testing system 10 that is capable of nondestructively probing a test
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specimen 12 to obtain structural information about the internal features of the test j
specimen 12. For example, the testing system 10 may be employed to identify the tI
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presence and/or location of one or more defects. The testing system 10 includes a |
segmented probe 14 positioned on a surface 16 of the test specimen 12 and a control
and processing system 18 coupled to the segmented probe 14 via data connection 20.
As discussed in more detail below, in certain embodiments, the control and processing f
system 18 may include a variety of components that enable the control and processing t
system 18 to both supply the segmented probe 14 with power and control signals and f
to receive echo signals from the segmented probe 14. To that end, the control and processing system may include various input and output devices, such as keyboards, i
^ P data acquisition and processing controls, an image display panel, user interfaces, and
so forth.
Further, it should be noted that the data connection 20 may transmit digital I
or analog data between the control and processing system 18 and the segmented probe |
14. In this way, the data connection 20 may facilitate the bidirectional exchange of data between the segmented probe 14 and the control and processing system 18. For
instance, in some embodiments, the control and processing system 18 may transmit I
control signals to the segmented probe 14 and receive matrices of digital data or j
analog signals that represent echo signals returned from the test specimen during an j
ultrasonic inspection method. f
In certain embodiments, the segmented probe 14 includes arrays of [
£L transducer segments that produce ultrasonic excitation signals and receive echo signals resulting from an interaction of the ultrasonic excitation signals and the test specimen 12. Each individual transducer segment of the segmented probe 14 is generally capable of converting electrical energy into mechanical energy for transmission, and is further capable of converting mechanical energy into electrical I
energy for receiving purposes. As appreciated by one skilled in the art, in certain embodiments, the transducer segments may have one or more features that enable i
efficient transmission, detection, and processing of ultrasonic signals. Still further, I
each transducer segment may include traditional components, such as a piezoelectric
ceramic, a matching layer, an acoustic absorber, and so forth. Additionally, the
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transducer segments may be of any type suitable for use with ultrasonic tomography, j
such as broad-bandwidth transducers, resonance transducers, and so forth. Indeed, a f
variety of transducer segments known to those skilled in the art may be employed in |
presently disclosed embodiments, and the features of the transducer segments of the
segmented probe 14 for a given application may be implementation-specific.
During operation, the segmented probe 14 may be employed to probe the
test specimen 12 to identify and/or quantify the presence of one or more defects in the j
structure of the test specimen 12. For example, the segmented probe 14 may be I
utilized to identify the presence of cracks, cavities, or other imperfections in the test j
£% specimen 12. To that end, the segmented probe 14 may be placed in a suitable j
location on the surface 16 of the test specimen 12, and the transducer segments of the !
segmented probe 14 may be fired in a desired pattern to produce a rotatable, nonaxial-
symmetric sound field that is transmitted into the test specimen 12. Once fired, jj
pairs of transducer segments in the segmented probe 14 may receive echo signals that f
correspond to structural information of the test specimen 12. Subsequently, a
neighboring pair of transducer elements is activated. Firing these adjacent transducer
elements leads to a rotation of the sound field delivered to the test specimen. By j
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continuously moving from one pair of transducer elements to the other, the sound j
field can be rotated by approximately 180° leading to the starting configuration of the {
sound field. Once the desired transmitting and receiving cycles are complete, which I
can be accomplished by a 180° rotation of the sound field showing a two-fold f
rotational symmetry, the segmented probe 14 may be moved about the surface 16 of j
^ r the test specimen 12 to a variety of positions to obtain data corresponding to the j
volume of the test specimen 12. For example, the segmented probe 14 may be
translated along the width of the test specimen 12, as indicated by arrows 22, or along !
the length of the test specimen 12 to obtain similar data from a variety of positions on the surface 16 of the test specimen 12. I
FIG. 2 is a block diagram depicting an embodiment of the control and j;
processing system 18 of FIG. 1 that may be employed to control and/or power the {
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segmented probe 14. In the depicted embodiment, the control and processing system f
18 includes interface circuitry 24 that enables communication of data between *
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components of the control and processing system 18. The components in the depicted j
system 18 include a processor 26, an auxiliary processor 28, a memory 30, an S
auxiliary memory 32, a controller 34, auxiliary devices 36, a display system 38, and a j
display 40, although the components in any embodiment are implementation-specific and may depend on factors such as the type of segmented probe 14 being utilized.
During operation, when the control and processing circuitry 18 is receiving
information, the interface circuitry 24 receives data from the segmented probe 14 via the data connection 20. The interface circuitry 24 may receive data that corresponds j
to the echo signals received by the segmented probe 14 after the excitation signals
^jL have interacted with the test specimen 12. This data is then transmitted to the j
processor 26 and/or the auxiliary processor 28, where a tomographic reconstruction f
method may be utilized to reconstruct images corresponding to volumetric slices of
the test specimen 12. These volumetric slices may then be combined to reconstruct a
volumetric representation of the test specimen 12. In certain embodiments, the
processor 26 may include signal processing circuitry adapted to perform the foregoing
functions, and the auxiliary processor 28 may include circuitry programmed to further
process the data, for example, to filter the reconstructed slices or the reconstructed
volumetric representation. To that end, the processor 26 and/or the auxiliary
processor 28 may include various suitable microcontrollers, microprocessors, or other
desired circuitry. Further, in certain embodiments, the auxiliary processor 28 may be
integrated with the circuitry of the processor 26. Still further, the processor 26 may
also execute algorithms that control the operating functions of the test system. >
The generated volumetric slices and/or complete volumetric representations |
of the test specimen 12 may then be transmitted to the display system 38 via the
interface circuitry 24. The display system 38 generally includes circuitry adapted to
display volumetric representations of the test specimen 12 on the display 40. For
example, the display system 38 may include memory for storing the received data, a
graphics card, a user interface for communicating with an operator, and so forth. f
Additionally, the interface circuitry 24 may store the data received from the [
segmented probe 14, the processor 26, and/or the display system 38 to memory 30 10
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and/or to auxiliary memory 32. In certain embodiments, the memory 30 may be ;
utilized to store data relating to programs executed by the processor 26 and/or the [
auxiliary processor 28, and the auxiliary memory 32 may be utilized to store received
image data and/or data that may be loaded into the memory 30 prior to execution by i
the processor 26. The memory 30 and/or the auxiliary memory 32 may include
volatile or non-volatile memory, such as a computer readable media, read only
memory (ROM), random access memory (RAM), magnetic storage memory, optical [
storage memory, or a combination thereof j
Furthermore, a variety of control parameters may be stored in the memory j
^ H 30 along with code designed to provide a specific output during operation of the
testing system 10. For example, the memory 30 may store executable algorithms that
the controller 34 may selectively access depending on the auxiliary devices 36 that are
connected to the given system. The auxiliary devices 36 may include a keyboard, a j
printer, a recording device, a network interfacing device, a combination thereof, or j
any other external device that may be desired in the testing system 10. Further, the
controller 34 may access the memory 30 to access the algorithms corresponding to the
particular auxiliary devices 36 included in the system.
FIG. 3 depicts an embodiment of a circular segmented transducer probe 42
that may be employed in the testing system 10 of FIG. 1 to generate a rotatable, nonaxial-
symmetric sound field. The circular segmented transducer probe 42 has an
outer diameter 44 and an inner diameter 46 and includes a plurality of transducer
Jp\ segments 48 arranged in a circular array. In certain embodiments, the inner diameter j
46 of the circular probe 42 may be approximately zero, depending on one or more
manufacturing parameters. The circular array of transducer segments 48 includes a
plurality of pairs of opposite transducer segments, and the transducer segments within each pair may be adapted to receive and transmit signals concurrently with one
another, as described in more detail below. In the depicted embodiment, a first
transducer segment 50 and a second transducer segment 52 form a pair of opposite transducer segments. That is, the first transducer segment 50 and the second transducer segment 52 are disposed on opposite sides of the segmented transducer probe 42 about the inner diameter 46. Although only the pair of transducer segments
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50 and 52 is highlighted in the depicted embodiment, each set of oppositely disposed i
transducer segments 48 in the circular array forms a pair of opposite transducer l
segments. It should be noted that although in the illustrated embodiment, each pair includes two segments, in some embodiments each pair may include multiple
segments (e.g., a pair includes two segments opposite another two segments).
It should be noted that although the segmented transducer probe 42 of FIG.
3 is circular in shape, the segmented transducer probe may be any of a variety of
suitable shapes and sizes. Additionally, the transducer segments may be dimensioned
to accommodate the overall shape of the segmented transducer probe. For example,
^ . in one embodiment, the segmented probe may be rectangular, and, accordingly, the
^ ^ transducer segments may be rectangular in shape as well. Indeed, the configuration of
the segmented transducer probe may be implementation-specific, and the chosen
configuration may be partially or wholly determined by the size and shape of the test l
specimen.
During operation, the segmented transducer probe 42 of FIG. 3 may be
employed to produce a rotatable, non-axial-symmetric sound field 54, as depicted in
FIG. 4. The rotatable, non-axial-symmetric sound field 54 includes non-axialsymmetric
isobars 56 that can be transmitted into a test specimen to nondestructively
test the specimen for the presence, absence, location, and/or quantity of one or more
defects. That is, the non-axial-symmetric sound field is substantially elliptically. In
one embodiment, to generate the non-axial-symmetric sound field 54, the segmented
jm transducer probe 42 is placed in a desired location on the test specimen, and the
desired transducer segments are activated to produce ultrasonic excitation signals that
are transmitted into the test specimen. In an embodiment, the pair of opposite f
transducer segments 50 and 52 is fired, and the returning echo signal is received by
the desired two of the transducer segments 48. This process may be sequentially
repeated until all of the pairs of opposite transducer segments receive the returning
echo signals. In another embodiment, however, all the transducer segments 48 in the
circular array may be fired concurrently with one another, and each pair of opposite
transducer segments independently receives the returning echo signals. Regardless of
the manner in which the data is acquired at the location of the segmented probe 42, ;
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data is received for a multiplicity of rotation angles of the non-axial-symmetric sound j
field. Once the data is received, the segmented probe 42 is moved to the next location [
on the test specimen surface, and the process is repeated. In this manner, data 1
regarding the entire internal structural volume of the test specimen may be obtained I
and processed by the processing and control system 18 to identify the presence and j
quantity of defects.
FIG. 5 is a flow chart depicting a method 58 that may be utilized to probe a
test specimen with a segmented probe to obtain defect information about the structure
of the test specimen. The method 58 may begin by positioning (block 60) the
* i segmented probe on the test specimen in the first location on the surface of the test specimen. Two or more transducer segments may then be fired (block 62), thus transmitting the rotatable, non-axial-symmetric sound field into the test specimen. As
noted above, the transducer segments may be fired sequentially in pairs or all the ;
transducer segments in the array may be concurrently fired. The echo signals I
resulting from an interaction of the non-axial-symmetric sound field with the test f
specimen are then received (block 64) by a pair of transducer segments. The method
58 may then continue by determining (block 66) whether additional unfired
transducer segments are present. If unfired transducer segments are present, an
additional pair of opposite transducer segments may be fired (block 62), and the process may be repeated. f
However, if all transducer segments have been fired, the segmented
JM transducer may be translated (block 68) along the surface of the test specimen to the
desired additional locations. The acquisition process may then be repeated (block 70)
at each additional location, as described above with respect to blocks 62-66. After a ?
set of data corresponding to the volume of the test specimen is acquired, the data may I
be transmitted to the control and processing circuitry, and a back projection algorithm I
may be utilized (block 72) to reconstruct an image of the test specimen. The
reconstructed image may be a volumetric slice of the test specimen or an entire
volumetric representation of the test specimen.
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The depicted method 58 also includes determining (block 74) the presence,
absence, location, and/or quantity of defects in the test specimen. However, it should
be noted mat while in some embodiments, the test system may determine the
presence, absence, location and/or quantity of defects through the control and
processing circuitry, in other embodiments, this step may be performed by an
operator. That is, in certain embodiments, the testing system may be adapted to
acquire and process the data corresponding to structural information about the test
specimen, and an operator may analyze the data to obtain defect information about the
structure. I
^ > FIGS. 6-11 schematically depict an embodiment of a tomographic >
reconstruction method that can be employed to reconstruct a representation of the test
specimen. Specifically, FIG. 6 depicts a rotated sound field 76 being employed to
probe a defect 78 that may be present in a test specimen. The rotated sound field 76 is i
generated while the segmented probe is positioned in a first location on the surface of the test specimen. As shown, the rotated sound field 76 includes a first sound field
rotation 79, a second sound field rotation 80, a third sound field rotation 82, and a
fourth sound field rotation 84. At each sound field rotation, echo signals resulting |
from interaction of the sound field with the test specimen are obtained. A matrix 86, ;
as shown in FIG. 7, is generated that captures the received information from the first scan position. The matrix 86 may be stored to memory 30 or auxiliary memory 32 in f
some embodiments. For example, since sound field rotations 79, 80, and 82 do not j
interact with the defect 78, these sound field rotations do not contribute positive
QP values to the matrix 86. However, because sound field rotation 84 does interact with j
defect 78, this interaction is recorded, and the amplitude of the received signal is l
stored in blocks 88, 90, and 92 of the matrix 86. The segmented probe is then translated to a second position along the part, I
as illustrated by arrow 94. That is, the segmented probe is moved along the test
specimen, as shown by arrows 22 in FIG. 1. Subsequently, another rotated sound field 96 is generated, as shown in FIG. 8. As before, the rotated sound field 96 f
includes a first sound field rotation 98, a second sound field rotation 100, a third sound field rotation 102, and a fourth sound field rotation 104. Here again, at each j
l
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sound field rotation, echo signals resulting from interaction of the sound field with the test specimen are obtained. Another matrix 106, as shown in FIG. 9, is generated. {
The matrix 106 represents a sum of a probe matrix obtained from probing with the sound field 76 and a shifted probe matrix obtained from probing with the sound field [
96. For example, sound field rotations 100, 102, and 104 do not interact with the j
defect 78 when the segmented probe is positioned in the second location, and, I
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accordingly, these sound field rotations do not contribute positive values to the matrix |
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106. However, sound field rotation 98 does interact with defect 78, and this I
interaction is recorded in a second probe matrix corresponding to the second probe
I
location. This second probe matrix is shifted and added to the first probe matrix to f
J ( | generate matrix 106. The blocks 108, 90, and 110 of the matrix 106 reflect the I
amplitude of the signal recorded after probing with sound field 96. j
The segmented probe is again translated to another position along the part, j
as illustrated by arrow 112. That is, the segmented probe is moved further along the I
width of the test specimen, as shown by arrows 22 in FIG. 1. An additional rotated J
sound field 114 is then generated, as shown in FIG. 10. The rotated sound field 114
includes sound field rotations 116, 118, and 120 that do not interact with the defect 78 }
when the segmented probe is positioned in the third location. Additionally, the sound j
field 114 includes a sound field rotation 122 that does interact with the defect 78, and |
this interaction is recorded in a third probe matrix corresponding to the third probe location. This third probe matrix is shifted and added to the matrix 106 to generate f
matrix 124, as shown in FIG. 11. The blocks 126, 90, and 128 of the matrix 124 Wf reflect the amplitude of the signal recorded after probing with sound field 114. In this |
way, the matrix 124 includes the information from the first probe matrix, a shifted j
second probe matrix, and a shifted third probe matrix. This process is repeated for all j
I
the desired scan positions, thus resulting in a reconstructed slice of the test specimen. {
It should be noted that after generating the image matrix, which reflects the J
information stored in the plurality of probe matrices, one or more filters may be used
to further improve the image quality. For example, in one embodiment, an edge- I
sharpening filter, such as a Shepp-Logan-Filter, may be utilized. J
15
It should be noted that the control and processing circuitry may utilize the
matrix 124 to generate one or more volumetric slices of the test specimen. In this j
way, the segmented probes disclosed herein may be utilized in combination with a 1
tomographic reconstruction method to nondestructively obtain volumetric information
about the test specimen. Again, by utilizing a rotatable, non-axial-symmetric sound
field to probe the test specimen, the resolution of the testing system may be increased
as compared to traditional systems, thus potentially enabling better resolution of j
defects present in the test specimen. i
This written description uses examples to disclose the invention, including [
^ * the best mode, and also to enable any person skilled in the art to practice the
invention, including making and using any devices or systems and performing any j
incorporated methods. The patentable scope of the invention is defined by the claims, i
and may include other examples that occur to those skilled in the art. Such other I
examples are intended to be within the scope of the claims if they have structural I
elements that do not differ from the literal language of the claims, or if they include
equivalent structural elements with insubstantial differences from the literal language }
of the claims.

WE CLAIM:
1. A system, comprising:
a segmented transducer probe comprising a plurality of transducer segments
configured to transmit ultrasonic excitation signals into a test specimen and to receive
echo signals resulting fi-om an interaction of the ultrasonic excitation signals and the
test specimen; and
a processing system configured to receive data fi-om the segmented transducer
probe that corresponds to the received echo signals and to utilize a tomographic
reconstruction method to reconstruct an image corresponding to at least one
^ p volumetric slice of the test specimen.
2. The system of claim 1, wherein the processing system is configured to
utilize the tomographic reconstruction method to reconstruct a plurality of volumetric
slices of the test specimen and to combine the plurality of volumetric slices to
reconstruct a volumetric representation of the test specimen.
3. The system of claim 1, wherein the segmented transducer probe
comprises an array of opposite pairs of transducer segments spatially arranged in a
circular arrangement, each opposite pair of transducer segments comprising a first
transducer segment and a second transducer segment opposite from the first
transducer segment.
c
4. The system of claim 3, wherein the first transducer segment and the
second transducer segment of each of the opposite pairs of transducer segments are
configured to transmit the ultrasonic excitation signals concurrently with one another
and to receive the echo signals concurrent with one another.
5. The system of claim 3, wherein the opposite pairs of transducer
segments are configured to concurrently transmit the ultrasonic excitation signals, and
the echo signals are configured to be sequentially received by each pair of opposite
transducer segments.
17
6. The system of claim 1, wherein the segmented transducer probe is
configured to transmit the ultrasonic excitation signals as a rotatable, non-axialsymmetric
sound field.
7. The system of claim 1, wherein the processing system comprises a
display system configured to display a visual representation of the reconstructed
image of the test specimen.
8. The system of claim 1, wherein the processing system is configured to
evaluate the reconstructed image to determine at least one of a presence of defects
^ p present in the test specimen, an absence of defects present in the test specimen, a
location of defects present in the test specimen, or a quantity of defects present in the
test specimen.
9. A system, comprising:
a circular segmented transducer probe, comprising:
an array of transducer segments circularly disposed about an iimer
diameter of the circular segmented transducer probe and comprising a plurality
of opposite pairs of transducer segments;
wherein the plurality of opposite pairs of transducer segments is
configured to be activated to generate a rotatable, non-axial-symmetric sound
field.
10. The system of claim 9, wherein each of the opposite pairs of transducer
segments comprises a first transducer segment and a second transducer segment that
are configured to concurrently receive echo signals resulting fi-om an interaction of
the rotatable, non-axial-symmetric sound field and a test specimen.
11. The system of claim 10, comprising a processor configured to receive
data from the circular segmented transducer probe that corresponds to the received
echo signals and to utilize a tomographic reconstruction method to reconstruct an
image corresponding to at least one volumetric slice of the test specimen.
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12. The system of claim 11, wherein the processor is configured to utilize
a tomographic reconstruction method to reconstruct a plurality of volumetric slices of
the test specimen and to combine the pluraUty of volumetric slices to reconstruct a
volumetric representation of the test specimen.
13. The system of claim 10, wherein the processor is configured to
evaluate the reconstructed image to determine at least one of a presence of defects
present in the test specimen, an absence of defects present in the test specimen, a
location of defects present in the test specimen, or a quantity of defects present in the
test specimen.
14. A method, comprising:
transmitting a rotatable, non-axial-symmetric sound field to a test specimen;
receiving echo signals resulting fi-om an interaction between the rotatable,
non-axial-symmetric sound field and the test specimen; and
utilizing the received echo signals and a tomographic reconstruction method to
reconstruct an image corresponding to at least one volumetric slice of the test
specimen.
15. The method of claim 14, wherein transmitting the rotatable, non-axialsymmetric
sound field to the test specimen comprises activating two or more
segmented transducers of a segmented transducer probe.
16. The method of claim 14, wherein receiving the echo signals comprises
receiving the echo signals from pairs of opposite transducer segments of a segmented
transducer probe.
17. The method of claim 14, comprising positioning a segmented
transducer probe on a surface of the test specimen.
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18. The method of claim 17, comprising translating the segmented
transducer probe to a plurality of positions along the surface of the test specimen.
19. The method of claim 18, wherein utilizing the received echo signals
and the tomographic reconstruction method to reconstruct the image comprises
generating matrices of a numerical representation of the received echo signals
corresponding to each of the plurality of positions and summing the generated
matrices.
20. The method of claim 14, comprising reconstructing a volumetric
^ B representation of the test specimen from the at least one volumetric slice and
displaying the volumetric representation on a display.