Fluid-filled probe support for non-destructive test (NDT)

Abstract

A flexible probe "cushion" or "waterbed" configuration, where a flexible probe support houses a fluid (e.g., a substantially incompressible liquid), can help to conform a non-destructive test (NDT) inspection probe to a surface of an object under test. For example, force applied to a liquid (e.g., water) filling a polymer probe support can allow deformation and conformity of a face of the probe support to an object under test. A flexible eddy current array (ECA) sensor assembly can be supported at a face of the probe support assembly and can also be deformed to conform to curvature or irregularity in the surface of the object under test.

Description

FLUID-FILLED PROBE SUPPORT FOR NON DESTRUCTIVE TEST (NDT)CLAIM OF PRIORITY

[0001] This patent application claims the benefit of priority of Samuel Guimond, U.S. Provisional Patent Application Number 63 / 624,663, titled “WATERBED HOUSING FORNON-DESTRUCTIVE TEST (NDT),” filed on January 24, 2024 (Attorney Docket No. 6409.278PRV), which is hereby incorporated by reference herein in its entirety.FIELD OF THE DISCLOSURE

[0002] This document pertains generally, but not by way of limitation, to apparatus and techniques for non-destructive inspection such as facilitating eddy current inspection, and more particularly, to apparatus and techniques for conforming a flexible probe assembly to a surface of an object under test using force (or corresponding pressure) applied to a fluid-filled probe support.BACKGROUND

[0003] Non-destructive testing (NDT) can refer to use of one or more different techniques to inspect regions on or within an object, such as to ascertain whether flaws or defects exist, or to otherwise characterize the object being inspected. One class of non-destructive testing can include use of an eddy current testing approach where electromagnetic energy is applied to the object and resulting induced currents on or within the object are detected, with the values of a detected current (or a related impedance) providing an indication of the structure of the object under test, such as to indicate a presence of a crack, scratch, void, porosity, or other inhomogeneity (e.g., corrosion or pitting). Generally, an eddy current (EC) sensor includes one or more sensor elements such as inductive coils that can be excited using an alternating current (AC) source. Such coils (or other electromagnetic sensing elements such as hall sensors) can be used for receiving a signal indicative of an induced eddy current on or within the structure in response to such excitation, using either the same coil for both excitation and pickup (e.g., connected through a bridge circuit), or using one coil for transmission and another coil for pickup. Generally, eddy current inspection can besensitive to variation in a distance between an EC sensor and the object under test, such as compromising sensitivity if the EC sensor is lifted away from a surface of an object under test.SUMMARY OF THE DISCLOSURE

[0004] A non-destructive inspection probe assembly, such as an eddy current array (ECA) sensor probe assembly, can include a fluid-filled flexible probe support. The fluid-filled flexible probe support can have an internal reservoir or cavity pressurized with a fluid (e.g., a substantially incompressible liquid such as water) to conform an outer surface of the probe support to an object under inspection having a curved or irregular surface. The outer surface of the probe support can include or can support one or more respective outward-facing eddy current sensors, and in this manner, eddy current inspection can be performed on the object under inspection with reduced or mitigated risk of lift-off even if the object under inspection has a curved or irregular surface.

[0005] Curved surfaces of objects under inspection can have convex or concave profiles, or compound curvature, such as including curvature in more than one axis. The flexible probe support configuration described herein can be fabricated using polymer materials, such as elastomeric materials. Such materials can include polymers compatible with molding or compatible with additive manufacturing processing. Such materials can include silicone or thermoplastic elastomer materials (e.g., abbreviated “TPx” or “TPE”) such as thermoplastic polyurethane (TPU), or thermoplastic polyamide (TP A), as illustrative examples.

[0006] A flexible probe “cushion” or “waterbed” configuration, where a flexible probe support houses a fluid (e.g., a substantially incompressible liquid), can help to conform a non-destructive test (NDT) inspection probe to a surface of an object under test. For example, force applied to a liquid (e.g., water) filling a polymer probe support can allow deformation and conformity of a face of the probe support to an object under test. A flexible eddy current array (ECA) sensor assembly can be supported at a face of the probe support assembly and can also be deformed to conform to curvature or irregularity in the surface of the object under test.

[0007] In an example, a non-destructive inspection probe assembly can include a flexible probe support defining a hollow region configured to be filled with fluid andpressurized, the flexible probe support defining a deformable flexible wall to conform to an object under inspection and an outward-facing planar flexible non-destructive inspection sensor assembly coupled to the flexible wall to conform to the object under inspection as the flexible wall deforms. In an example, the planar flexible nondestructive inspection sensor assembly comprises an eddy current sensor. In an example, the flexible probe support comprises a channel in fluid communication with the hollow region to couple with a pressurized fluid source. In an example, a protective film covers the planar flexible non-destructive inspection sensor assembly.

[0008] In an example, a method for performing non-destructive inspection comprises pressurizing the hollow region of the flexible probe support to conform the deformable flexible wall to a surface of an object under inspection and performing a non-destructive inspection acquisition using the outward-facing planar flexible nondestructive inspection sensor assembly. In an example, the performing the nondestructive inspection comprises scanning the flexible probe support across the surface of the object under test during or before performing the non-destructive inspection. In an example, the scanning is performed using a robotic manipulator. In an example, the flexible probe support is fabricated using a molding operation or an additive manufacturing approach.

[0009] This summary is intended to provide an overview of subject matter of the present patent application. It is not intended to provide an exclusive or exhaustive explanation of the invention. The detailed description is included to provide further information about the present patent application.BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In the drawings, which are not necessarily drawn to scale, like numerals may describe similar components in different views. Like numerals having different letter suffixes may represent different instances of similar components. The drawings illustrate generally, by way of example, but not by way of limitation, various embodiments discussed in the present document.

[0011] FIG. 1 illustrates generally an example comprising a non-destructive inspection system, such as can include or use a flexible fluid-filled probe support.

[0012] FIG. 2 is a diagram illustrating an exploded view a flexible fluid-filled probe support and a sensor assembly.

[0013] FIG. 3A illustrates generally an example comprising a flexible fluid-filled probe support at rest.

[0014] FIG. 3B illustrates generally an example comprising a flexible fluid-filled probe support when pressurized and conforming to a curved surface of an objected under inspection.

[0015] FIG. 4 illustrates generally an example of a probe assembly that serve as an inspection head or end effector, including the flexible fluid-filled probe support.

[0016] FIG. 5 illustrates generally a technique, such as a method for conforming a fluid-filled flexible probe support to an object under inspection.DETAILED DESCRIPTION

[0017] Non-destructive inspection can be performed using a probe assembly, such as a hand-held probe that can include a housing, interconnections, electronic circuitry, and a sensor (or array of sensors). For example, for eddy current array (ECA) inspection, a flexible printed circuit board can include respective eddy current sensor elements (e.g., planar inductive coils). The present inventor has recognized, among other things, that non-destructive inspection may be performed by scanning or translating a probe assembly along surfaces that are not perfectly flat, such as including either convex or concave surface topology (or both). Examples of such curved surfaces include structures such as airfoils or turbine blades. Irregular surfaces can cause a rigid sensor assembly to be lifted away from a surface of an object being inspected, such as hindering inspection (e.g., causing error due to lift-off or causing false flaw indications). In one approach, a solid foam pad can be used, such as upon which an inspection probe sensor assembly is fixed. However, use of a foam material can present various challenges, such as lacking mechanical durability, snagging as the probe is translated in contact with a surface, or presenting difficulties with respect to replacement.

[0018] The present inventor has recognized, among other things, that use of a flexible probe “cushion” or “waterbed” configuration, where a flexible probe support houses a fluid (such as a substantially incompressible liquid), can help to conform an NDT inspection probe to a surface of an object under test. For example, force applied to a liquid (e.g., water) filling a polymer probe support can allow deformation and conformity of a face of a probe support assembly to an object under test. A flexibleeddy current array (ECA) sensor assembly can be supported at a face of the probe support assembly and can also be deformed to conform to curvature or irregularity in the surface of the object under test. The fluid-filled flexible probe support structure can be fabricated from a flexible polymer material.

[0019] FIG. 1 illustrates generally an example comprising a non-destructive inspection system 100, such as can be used to perform at least a portion one or more techniques as shown and described herein or can use apparatus as shown and described elsewhere in this document. The non-destructive inspection system 100 can include a test instrument 140, such as a hand-held or portable assembly. The test instrument 140 can be electrically coupled to a probe assembly 150, such as using a multi -conductor interconnect 130. The probe assembly 150 can include one or more sensors, such as an eddy current coil array 154 (ECA). The EC coils are electromagnetically coupled with a target 158 (e.g., a test specimen or “object-under- test”) and the system 100 can be used to detect a flaw 160 using one or more techniques shown and described in this document. The ECA 154 can be a four-coil planar cross-wound sensor (CWS) or an array of such sensors, or the ECA 154 can have another configuration, such as a one-dimensional array, or a two-dimensional array configuration, as illustrative examples. The ECA 154 can be flexible or can otherwise follow a linear or curved contour or can include an array of elements extending in multiple axes. Element size and pitch can be varied according to the inspection application. As shown and described elsewhere herein, a fluid-filled flexible probe support 156 can support the EC coil array 154, such as to assist in conforming the EC coil array 154 to a surface of the target 158. For example, a robotic manipulator or other apparatus can be used to mechanically scan the EC coil array 154 relative to the target 158.

[0020] A modular probe assembly 150 configuration can be used, such as to allow a test instrument 140 to be used with various different probe assemblies. The test instrument 140 can include digital and analog circuitry, such as a front-end circuit 122 including one or more transmit signal chains (forming a transmitter circuit), receive signal chains (forming a receiver circuit), or switching circuitry (e.g., a multiplexer circuit 123). The transmit signal chain can include amplifier and filter circuitry, such as to provide an alternating current (AC) excitation signal for delivery through aninterconnect 130 to a probe assembly 150.

[0021] While FIG. 1 shows a single probe assembly 150 and a single ECA 154, other configurations can be used, such as multiple probe assemblies connected to a single test instrument 140, or multiple arrays 154 used with a single probe assembly 150. Similarly, a test protocol can be performed using coordination between multiple test instruments 140, such as in response to an overall test scheme established from a respective test instrument 140 or established by another remote system such as a compute facility 108 or general-purpose computing device such as a laptop 132, tablet, smart-phone, desktop computer, or the like. The test scheme may be established according to a published standard or regulatory requirement and may be performed upon initial fabrication or on a recurring basis for ongoing surveillance, as illustrative examples.

[0022] The front-end circuit 122 can be coupled to and controlled by one or more processor circuits, such as a processor circuit 102 included as a portion of the test instrument 140. The processor circuit can be coupled to a memory circuit 104, such as to execute instructions that cause the test instrument 140 to perform one or more of EC acquisition, processing, or storage of data relating to an EC inspection. The test instrument 140 can be communicatively coupled to other portions of the system 100, such as using a wired or wireless communication interface 120.

[0023] Performance of one or more techniques as shown and described herein can be accomplished on-board the test instrument 140 or using other processing or storage facilities such as using a compute facility 108 or a general -purpose computing device such as a laptop 132, tablet, smart-phone, desktop computer, or the like. For example, processing tasks that would be undesirably slow if performed on-board the test instrument 140 or beyond the capabilities of the test instrument 140 can be performed remotely (e.g., on a separate system, such as using physical or virtualized processing resources), such as in response to a request from the test instrument 140. The test instrument 140 can include a display 110, such as for presentation of configuration information or results, and an input device 112 such as including one or more of a keyboard, trackball, function keys or soft keys, mouse-interface, touch-screen, stylus, or the like, for receiving operator commands, configuration information, or responses to queries.

[0024] As mentioned elsewhere herein, the present inventor has recognized thatinspection of curved structures, such as complex three-dimensionally curved structures can present various challenges. For EC inspection of such structures using automated inspection apparatus, positioning and deformation of an EC sensor are generally controlled such as to avoid lift-off from the object under inspection, or damage to the probe assembly or the object under inspection. Use of a spring-loaded EC sensor probe or a foam probe support may not be ideal. Accordingly, the present inventor has recognized that use of a fluid-filled (e.g., liquid filled) flexible probe support can address such challenges. For example, FIG. 2 is a diagram illustrating an exploded view a flexible fluid-filled probe support 256 and a sensor assembly 254, such as forming a portion of an inspection probe assembly 250. The flexible fluid- filled probe support 256 can be formed (e.g., molded or additively manufactured) from an elastomeric material, such as a silicone material.

[0025] The flexible sensor assembly 254 can include one or more eddy current sensor elements 255, such as planar winding structures. An active surface of the flexible sensor assembly 254 can be oriented to face outward from the flexible sensor assembly 254, such as to be placed in proximity to an object under test. For example, one or more cover layers, such as a protective film 257 or cover, can be placed over the flexible sensor assembly 254 and at least a portion of the surface of the flexible fluid-filled probe support 256. For example, a portion of the film can include an adhesive to anchor the film to the flexible fluid-filled probe support 256, such as removably. This can help to retain the flexible sensor assembly 254 against the flexible fluid-filled probe support 256 and to avoid snagging or binding of the edges of the flexible sensor assembly 254 as the probe assembly 250 is translated or scanned across a surface of an object under test.

[0026] As shown in FIG. 2, the flexible fluid-filled probe support 256 can include or define a recessed region or channel 251, such as defined by one or more ribs 252, such as to receive a planar sensor region of the flexible sensor assembly 254, such as avoiding protrusion of the flexible sensor assembly 254 outward from the bottom of the flexible fluid-filled probe support 256 (e.g., establishing a flush or near-flush configuration) with the flexible sensor assembly residing in the channel 251. The flexible fluid-filled probe support 256 can include other features, such as a rim or lip 274 to facilitate coupling of a hollow interior region of the flexible fluid-filled probe support 256 to a fluid source, such as a pressurized water supply.

[0027] FIG. 3A illustrates generally an example comprising a flexible fluid-filled probe support 356 at rest. The views shown in FIG. 3A and FIG. 3B can represent cross-sectional views where the flexible fluid-filled probe support 356 defines a hollow interior cavity 376 that can be filled with a fluid (generally a substantially incompressible liquid such as water). The flexible fluid-filled probe support 356 can support an outward-facing eddy current (EC) sensor assembly 354, as discussed in other examples herein, where a bottom wall 366 is configured to deform along with the EC sensor assembly 354. For example, the EC sensor assembly 354 can include a flexible printed circuit assembly having a polymer substrate (e.g., polyimide) and corresponding metallization layers defining respective EC sensor windings. In a static configuration where the bottom wall 366 is not deformed by conforming to a surface of an objective under inspection 358, the cavity 376 is in equilibrium with a pressurized fluid source coupled to a rim 374.

[0028] By contrast, FIG. 3B illustrates generally an example comprising a flexible fluid-filled probe support 356 when pressurized and conforming to a curved surface of an objected under inspection 358. An input pressure 378 can be applied and is transmitted through a passage from a nozzle comprising the rim 374, and through the interior cavity 376 of the flexible fluid-filled probe support 356 to the bottom wall 366. The input pressure 378 establishes a uniform distribution of force (as indicated by arrows) across the deformable bottom wall 366, conforming the EC sensor assembly 354 to a surface of the object under inspection 358. In this manner, the surface of the EC sensor assembly 354 is adapted to fill in gaps or otherwise follow a contour of the object under inspection with substantially equally distributed forces.

[0029] The various flexible fluid-filled probe support configurations shown in this document can be manufactured using a variety of different approaches. For example, an elastomer such as silicone or a thermoplastic elastomer can be used. Examples of thermoplastic elastomers include thermoplastic polyurethane material (TPU) or a thermoplastic polyamide (TP A) material. Such materials can withstand transient exposure to hydrocarbon-based fluids or contaminants such as hydraulic fluid, such as where the flexible probe support is used for ECA inspection in aerospace, maritime, chemical process, oil or pipeline services, or other applications.

[0030] FIG. 4 illustrates generally an example of a probe assembly 450 that serve as an inspection head or end effector for a robotic manipulator or other apparatusfacilitating automated inspection. The probe assembly 450 can include or house a flexible fluid-filled probe support 456 as shown and described in other examples in this document (e.g., FIG. 2 and FIG. 3A). An active surface 451 of the flexible fluid- filled probe support 456 can be established where an EC sensor or an array of such sensors are placed on a surface of an object under inspection. For example, where a flexible sensor assembly is used, a flexible interconnection can terminate in connector region 431, such as an edge connector formed using the flexible printed circuit board (PCB) assembly. The flexible interconnection can include features such as folds, curves, or bends to permit the flexible sensor assembly to translate or flex as the flexible fluid-filled probe support 456 is deformed.

[0031] As shown in FIG. 4, the probe assembly 450 can include a housing 434 in which the flexible fluid-filled probe support 456 is installed, and other features such as rollers 438A and 438B, such as to follow a surface or contour of an object under inspection as the probe assembly 450 is translated relative to the object under inspection. Other features can include one or more pivoting locations 436, such as to allow the rollers 438A and 438B, and the flexible fluid-filled probe support 456 to tilt as the probe assembly 450 is translated relative to an object under inspection.

[0032] FIG. 5 illustrates generally a technique 500, such as a method for conforming a fluid-filled flexible probe support to an object under inspection. At 515, a hollow portion of the flexible probe support can be pressurized, such as with a substantially incompressible liquid. At 520, in response, at least a portion of the flexible probe support is conformed to surface of the object under inspection. At 525, nondestructive inspection can be performed on the object under inspection, using an outward-facing sensor supported by the flexible probe support. For example, such inspection can include an eddy current inspection using a single eddy current sensor or an array of such sensors. Optionally, at 505, the technique 500 can include fabricating a flexible probe support that is conformable to a surface of an object under inspection, such as by additive manufacturing or molding the probe support. At 510, a flexible sensor assembly can be installed in an outward-facing region of the flexible probe support (e.g., mating the flexible sensor assembly with the outward-facing region). For example, a modular configuration can be used where different flexible probe support geometries and flexible sensor assemblies can be paired depending on the inspection application.Various Notes

[0033] Each of the non-limiting aspects above can stand on its own or can be combined in various permutations or combinations with one or more of the other aspects or other subject matter described in this document.

[0034] The above detailed description includes references to the accompanying drawings, which form a part of the detailed description. The drawings show, by way of illustration, specific embodiments in which the invention can be practiced. These embodiments are also referred to generally as “examples.” Such examples can include elements in addition to those shown or described. However, the present inventor also contemplates examples in which only those elements shown or described are provided. Moreover, the present inventor also contemplates examples using any combination or permutation of those elements shown or described (or one or more aspects thereof), either with respect to a particular example (or one or more aspects thereof), or with respect to other examples (or one or more aspects thereof) shown or described herein.

[0035] In the event of inconsistent usages between this document and any documents so incorporated by reference, the usage in this document controls.

[0036] In this document, the terms “a” or “an” are used, as is common in patent documents, to include one or more than one, independent of any other instances or usages of “at least one” or “one or more.” In this document, the term “or” is used to refer to a nonexclusive or, such that “A or B” includes “A but not B,” “B but not A,” and “A and B,” unless otherwise indicated. In this document, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.” Also, in the following claims, the terms “including” and “comprising” are open-ended, that is, a system, device, article, composition, formulation, or process that includes elements in addition to those listed after such a term in a claim are still deemed to fall within the scope of that claim. Moreover, in the following claims, the terms “first,” “second,” and “third,” etc., are used merely as labels, and are not intended to impose numerical requirements on their objects.

[0037] Method examples described herein can be machine or computer-implemented at least in part. Some examples can include a computer-readable medium or machine- readable medium encoded with instructions operable to configure an electronic device ioto perform methods as described in the above examples. An implementation of such methods can include code, such as microcode, assembly language code, a higher-level language code, or the like. Such code can include computer readable instructions for performing various methods. The code may form portions of computer program products. Such instructions can be read and executed by one or more processors to enable performance of operations comprising a method, for example. The instructions are in any suitable form, such as but not limited to source code, compiled code, interpreted code, executable code, static code, dynamic code, and the like.Further, in an example, the code can be tangibly stored on one or more volatile, non- transitory, or non-volatile tangible computer-readable media, such as during execution or at other times. Examples of these tangible computer-readable media can include, but are not limited to, hard disks, removable magnetic disks, removable optical disks (e.g., compact disks and digital video disks), magnetic cassettes, memory cards or sticks, random access memories (RAMs), read only memories (ROMs), and the like.

[0038] The above description is intended to be illustrative, and not restrictive. For example, the above-described examples (or one or more aspects thereof) may be used in combination with each other. Other embodiments can be used, such as by one of ordinary skill in the art upon reviewing the above description. The Abstract is provided to allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Also, in the above Detailed Description, various features may be grouped together to streamline the disclosure. This should not be interpreted as intending that an unclaimed disclosed feature is essential to any claim. Rather, inventive subject matter may he in less than all features of a particular disclosed embodiment. Thus, the following claims are hereby incorporated into the Detailed Description as examples or embodiments, with each claim standing on its own as a separate embodiment, and it is contemplated that such embodiments can be combined with each other in various combinations or permutations. The scope of the invention should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

Claims

THE CLAIMED INVENTION IS:

1. A non-destructive inspection probe assembly, comprising: a flexible probe support defining a hollow region configured to be filled with fluid and pressurized, the flexible probe support defining a deformable flexible wall to conform to an object under inspection; and an outward-facing planar flexible non-destructive inspection sensor assembly coupled to the flexible wall to conform to the object under inspection as the flexible wall deforms.

2. The non-destructive inspection probe assembly of claim 1, wherein the planar flexible non-destructive inspection sensor assembly comprises an eddy current sensor.

3. The non-destructive inspection probe assembly of claim 2, wherein the eddy current sensor comprises an eddy current array sensor.

4. The non-destructive inspection probe assembly of any of claims 2 or 3, wherein the eddy current sensor comprises a flexible printed circuit assembly.

5. The non-destructive inspection probe assembly of any of claims 1 through 4, wherein the flexible probe support comprises a channel in fluid communication with the hollow region to couple with a pressurized fluid source.

6. The non-destructive inspection probe assembly of claim 5, further comprising the pressurized fluid source.

7. The non-destructive inspection probe assembly of any of claims 1 through 6, comprising a protective film covering the planar flexible non-destructive inspection sensor assembly.

8. The non-destructive inspection probe assembly of claim 7, wherein the film is replaceable without requiring removal or replacement of the planar flexible nondestructive inspection sensor assembly.

9. The non-destructive inspection probe assembly of any of claims 1 through 8, wherein the probe support comprises an elastomer.

10. The non-destructive inspection probe assembly of claim 9, wherein the probe support comprises a silicone material.

11. The non-destructive inspection probe assembly of claim 9, wherein the probe support comprises a material compatible with additive manufacturing.

12. The non-destructive inspection probe assembly of any of claims 1 through 11, wherein the fluid comprises a substantially incompressible liquid.

13. The non-destructive inspection probe assembly of claim 12, wherein the liquid comprises water.

14. A method for performing non-destructive inspection, comprising: pressurizing the hollow region of the flexible probe support of any of claims 1 through 13 to conform the deformable flexible wall to a surface of an object under inspection; and performing a non-destructive inspection acquisition using the outward-facing planar flexible non-destructive inspection sensor assembly.

15. The method of claim 14, comprising scanning the flexible probe support across the surface of the object under test during or before performing the nondestructive inspection.

16. The method of claim 15, wherein the scanning is performed using a robotic manipulator.

17. The method of any of claims 14 through 16, wherein the object under test comprises a curved or irregular surface.

18. The method of any of claims 14 through 17, comprising mating the planar flexible non-destructive inspection sensor assembly with the flexible probe support before performing the non-destructive inspection.

18. A method for fabricating the flexible probe support of any of claims 1 through13 comprising additively manufacturing or molding the flexible probe support of any of claims 1 through 13.

19. The method of claim 18, comprising mating the planar flexible non- destructive inspection sensor assembly with the flexible probe support.

20. The method of claim 18, comprising applying a protective fdm to the outwardfacing planar flexible non-destructive inspection sensor assembly.

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