A method and system for generating a single observation image

Abstract

A system and method for automatically detecting defects in a coating of a component are provided. In one aspect, a coating inspection system is provided. The coating inspection system includes a heating element that is operable to impart heat to the component as it traverses relative to the component. When the heating element traverses relative to the component and imparts heat thereto, an imaging device of the system captures an image of the component. The image indicates the transient thermal response of the component. The system may generate a single observation image using the captured image. The system may use the generated single observation image to detect and analyze defects.

Description

Technical Field

[0001] The present subject matter generally relates to systems and methods for automatically detecting defects in coatings, such as coatings on turbine machine components. Background Art

[0002] Some components of power and aero gas turbine engines are coated with thermal barrier coatings, particularly components positioned along the hot gas path of such engines. For example, metal turbine blades are typically coated with thermal barrier coatings to protect the metal structure of the blade from thermal damage during operation. A bond coat is typically provided between the metal structure and the thermal barrier coating to enhance the bond or adhesion between them. Generally, the thermal barrier coating can increase the effective service life of high-temperature metal components.

[0003] Detection of defects in thermal barrier coatings can ensure that only components with satisfactory coatings are assembled on the engine. Thus, these components are typically inspected for defects. Formation of coating defects can occur during coating processing, such as electron beam physical vapor deposition (EBPVD) coating processing. Common coating defects include spatter and pits. Spatter can form when too much coating material is deposited in a local area. Among other drawbacks, spatter can disrupt the fluid flow through the engine. Pits are also formed during coating processing, or in some cases, during engine operation. A pit is a void or space in the coating. If the spatter and / or pits in the thermal barrier coating exceed a certain size, depth, number, area fraction, or some combination thereof, the coating may need to be stripped and the component needs to be recoated. Coating rework can be expensive, time-consuming, and generally inconvenient.

[0004] Existing techniques for identifying defects in thermal barrier coatings are largely visual and are performed manually by an operator. Additionally, these techniques are subjective and not quantitative. Thus, when using existing techniques, some components that should be stripped and recoated pass quality inspection, while some components with satisfactory thermal barrier coatings fail quality inspection and are stripped and recoated. As a result, resources are wasted and additional costs are incurred.

[0005] Therefore, systems and methods that address one or more of the above challenges would be useful. In particular, improved systems and methods for evaluating the quality of thermal barrier coatings used in high-temperature applications would be beneficial. Summary of the Invention

[0006] Aspects of the present disclosure relate to a distributed control system and method for controlling a turbine. Aspects and advantages of the present invention will be set forth in part in the following description, or may be apparent from the description, or may be learned by practice of the present invention.

[0007] In one aspect, a method of generating a single observation image is provided. The method includes receiving, by one or more processors, a plurality of images captured by an imaging device, each of the plurality of images capturing a component having a coating as a heating element traverses and applies heat to the component in a traverse direction. The method further includes generating, by one or more processors, a plurality of masked images by, for each of the plurality of images, positioning a masking window relative to the heating element by one or more processors; and applying thermal data to pixels within the masking window of each of the plurality of images by one or more processors. Additionally, the method includes determining, at least in part based on the applied thermal data, a minimum or maximum value associated with each pixel on the plurality of masked images. The method further includes generating a single observation image of the component using the plurality of masked images such that the determined minimum or maximum value associated with each pixel on the plurality of masked images is represented in the single observation image.

[0008] In another aspect, a system is provided. The system includes a heating element, an imaging device, and a computing system having one or more processors and one or more memory devices. The one or more processors are configured to receive a plurality of images captured by the imaging device, each of the plurality of images capturing a component having a coating as the heating element traverses and applies heat to the component in a traverse direction. The one or more processors are further configured to generate a plurality of masked images by positioning a masking window relative to the heating element for each of the plurality of images; and applying thermal data to pixels within the masking window of each of the plurality of images. Additionally, the one or more processors are configured to determine, at least in part based on the applied thermal data, a minimum or maximum value associated with each pixel on the plurality of masked images. The one or more processors are further configured to generate a single observation image of the component using the plurality of masked images such that the determined minimum or maximum value associated with each pixel on the plurality of masked images is represented in the single observation image.

[0009] In a further aspect, a non-transitory computer-readable medium is provided. The non-transitory computer-readable medium includes computer-executable instructions that, when executed by one or more processors of a coating inspection system, cause the one or more processors to: receive a plurality of images captured by an imaging device, where each image of the plurality of images captures a component having a coating while a heating element of the coating inspection system traverses and applies heat to the component in a traverse direction; generate a plurality of masked images by: for each image of the plurality of images, positioning a masking window relative to the heating element; and applying thermal data to pixels within the masking window of each image of the plurality of images; determine a minimum or maximum value associated with each pixel on the plurality of masked images, at least in part based on the applied thermal data; and generate a single viewing image of the component using the plurality of masked images such that the determined minimum or maximum value associated with each pixel on the plurality of masked images is represented in the single viewing image.

[0010] These and other features, aspects, and advantages of the present invention will be better understood with reference to the following description and the appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the subject matter and, together with the description, serve to explain the principles of the subject matter. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] A complete and enabling disclosure of the present invention, including the best mode thereof, for the ordinary skilled person in the art, is set forth in the specification, which makes reference to the accompanying drawings, in which:

[0012] Figure 1 A perspective view of a coating inspection system in accordance with one embodiment of the present disclosure is provided;

[0013] Figure 2 A close-up schematic cross-sectional view of a portion of a component inspected by the Figure 1 system is provided;

[0014] Figure 3 A flowchart of an example method in which the Figure 1 system can perform a coating inspection process on a component is provided;

[0015] Figures 4 - 7 A schematic view of the Figure 1 heating element of the Figure 1 system traversing a component while applying heat to the component is provided;

[0016] Figure 8 A close-up view of the Figures 4 - 7 heating element traversing and heating the component is provided;

[0017] Figure 9 A schematic view of a single image of a component generated from a plurality of captured images is provided;

[0018] Figure 10 Provides a detailed view of a portion of a single image Figure 9 that details one method of detecting defects;

[0019] Figure 11 Provides a detailed view of a single image Figure 9 that details another method of detecting defects;

[0020] Figure 12 Provides a graph depicting the time-temperature curve of pixels according to one embodiment of the present disclosure;

[0021] Figure 13 Provides Figure 1 a block diagram of a computing system of a coating inspection system;

[0022] Figure 14 Provides a flowchart of an example method of generating a single observation image according to one embodiment of the present disclosure;

[0023] Figures 15 - 18 Provides a view of a number of images of a component captured by an imaging device when a heating element traverses and applies heat to the component in a traverse direction relative to the component;

[0024] Figure 19 Provides a schematic diagram of thermal data of pixels of a masking window applied to each image;

[0025] Figure 20 Provides a schematic diagram of a plurality of generated masking images according to one embodiment of the present disclosure;

[0026] Figure 21 Provides a view of an image of a component captured by an imaging device when a heating element traverses and applies heat to the component in a traverse direction relative to the component, and also depicts an example manner in which a masking window can be positioned relative to the heating element;

[0027] Figure 22 Provides a view of an image of a component captured by an imaging device when a heating element traverses and applies heat to the component in a traverse direction relative to the component, and also depicts another example manner in which a masking window can be positioned relative to the heating element;

[0028] Figure 23 Depicts a number of masking images according to one embodiment of the present disclosure; and

[0029] Figure 24 Depicts a single observation image having a plurality of pixels according to one embodiment of the present disclosure. Detailed Description

[0030] Reference will now be made in detail to the present embodiments of the invention, one or more examples of which are illustrated in the accompanying drawings. The detailed description uses numerical and alphabetical designations to refer to features in the drawings. Identical or similar designations have been used in the drawings and the description to refer to the same or similar parts of the invention. As used herein, the terms "first," "second," and "third" may be used interchangeably to distinguish one component from another and are not intended to denote the position or importance of each component. The terms "upstream" and "downstream" refer to the relative flow direction with respect to the flow of fluid in a fluid path. For example, "upstream" refers to the flow direction from which the fluid flows, and "downstream" refers to the flow direction toward which the fluid flows.

[0031] Generally speaking, the present disclosure provides systems and methods for detecting defects in coatings used on components of turbines, such as aerospace and power gas turbine engines. Compared with traditional systems / techniques, the system includes features that improve the detectability of defects (such as spatter and pits) in the coating with better accuracy. The systems and methods of the present disclosure can provide a faster, more accurate, and non-contact method for determining the quality of component coatings (such as thermal barrier coatings (TBCs) of metal turbine blades).

[0032] In one aspect, a coating inspection system for automatically detecting defects in a barrier coating of a component is provided. For example, the component can be a metal component of a gas turbine engine and the barrier coating can be a non-conductive coating, such as a thermal barrier coating. The coating inspection system includes a heating element for imparting heat to the component. The heating element is movable relative to the component. In this way, when the heating element applies heat to the component, the heating element can traverse across the component. The component can be held in place by a platform system. The system also includes an imaging device for capturing an image of the thermal response of the component when the heating element traverses across and applies heat to the component. For example, the imaging device can be an infrared (IR) imaging device (such as an IR camera). Notably, when the heating element traverses across and heats the component, a transient thermal gradient is generated between the non-defect regions and the defect regions of the barrier coating due to the different amounts of heat radiated outward from the non-defect regions of the coating and from the defects in the barrier coating. The imaging device can capture these transient thermal responses. The imaging device can capture the transient thermal responses when the heating element actively heats the component and / or when the component cools after being heated. By heating the component by 10 - 15 degrees Fahrenheit or more relative to the ambient temperature, the transient thermal gradient will significantly appear.

[0033] The system also includes a computing system having one or more processors and one or more memory devices. The computing system is communicatively coupled to the imaging device and the heating element. The one or more processors are configured to move the heating element across the component and, while the heating element is moving across the component, cause the heating element to heat the component. Moving the heating element across the component causes the component to exhibit the transient thermal response as described above. The one or more processors are further configured to cause the imaging device to capture a plurality of images of the component while the heating element is moving across and applying heat to the component. In this way, the captured images indicate the thermal response of the component. The one or more processors can detect one or more coating defects in the barrier coating of the component based at least in part on the thermal response of the component captured in the plurality of images. In some embodiments, the one or more processors can generate a single viewing image from the plurality of captured images such that the thermal response of the component (or a particular perspective or orientation of the component) is represented in a single image. This can facilitate the detection of defects and the analysis of the thermal response of the component.

[0034] In addition, in some embodiments, the computing system is communicatively coupled to an airflow generator. The one or more processors can cause the airflow generator to pulse air into one or more internal channels of the component. This can enhance the thermal response of the component such that the thermal response of the component is more easily captured by the imaging device. A method for automatic defect detection in a non-conductive coating of a component is also provided.

[0035] Thus, the systems and methods described herein utilize the transient nature of the thermal response of a component to detect spatter and pits in the non-conductive coating of the component. In summary, when the heating element moves across a particular section of the component, a pulsed alternating current (AC) (e.g., for a few seconds) passed through the heating element induces a current in the conductive substrate of that section, which in turn generates heat in the conductive substrate that radiates through the non-conductive coating. The thermal response of the component or that particular section of the component is detected by a high-speed imaging device (e.g., an IR camera). In particular, the transient thermal field interacts with defects in the section of the component, resulting in local thermal contrast differences or gradients that can be imaged or captured by the IR camera. When the heating element moves across and applies heat to the component, the IR camera can capture the local thermal response of some or all sections of the component.

[0036] Advantages of the present system and method include the ability to improve the detectability and quantification of defects by enhancing the contrast at the defect due to the transient nature of the inspection. Notably, the transient nature of the inspection improves the detectability of smaller defects that are not detectable with existing IR thermography methods and / or steady-state heating methods. For example, using the present system and method, spalls and pits as small as 10 mils in a coating are detectable. Specifically, spalls and pits from 10 mils to 7 mils can be detected. Compared to traditional systems and methods, the generation of transient thermal gradients enables the detection of such small defects. The transient thermal gradients enhance the contrast between the defect and non-defect regions of the coating of the component in the captured image.

[0037] Various parameters can affect the detectability and quantification of defects. For example, one parameter that can affect the detectability of defects is the frame rate of the imaging device (e.g., an IR camera). A higher frame rate allows for the capture of the transient thermal gradients at the defect with better thermal contrast, especially when detecting smaller defects (e.g., less than 10 mils), as the thermal gradient changes near small defects tend to disappear more quickly. In some example embodiments, the imaging device of the coating inspection system has a frame rate of at least 60 Hz. In some embodiments, the imaging device of the coating inspection system has a frame rate between 60 - 500 Hz. In some embodiments, the imaging device of the coating inspection system has a frame rate between 250 - 500 Hz.

[0038] Another parameter that can affect the detectability of defects is the spatial resolution of the imaging device. In some embodiments, the imaging device has a spatial resolution such that the imaging device is operably configured to detect defects or features as small as 80 microns (or approximately 0.003 inches). In such embodiments, for example, the imaging device can have a 25 mm lens and a 640X512 pixel detector IR camera. The working distance between the IR detector and the component can be set to 6 inches. In other embodiments, the imaging device can detect defects or features smaller than 80 microns (or approximately 0.003 inches) by using a 1024X1024 pixel detector IR camera and / or by reducing the working distance between the IR detector and the component (e.g., to less than 6 inches (depending on the minimum working distance requirements of the lens and IR detector)).

[0039] A further parameter that can affect the detectability of defects is the wavelength of the imaging device. In some example embodiments, the imaging device is a mid-wave IR camera (e.g., 3 - 6 μm). In some example embodiments, the imaging device is a long-wavelength IR camera (e.g., 7 - 14 μm). In some embodiments, the imaging device is one of at least two imaging devices of the system. At least one imaging device can be a mid-wave IR camera (e.g., 3 - 6 μm), and at least one imaging device can be a long-wavelength IR camera (e.g., 7 - 14 μm). Another parameter that can affect the detectability of defects is the thermal sensitivity of the imaging device. In some example embodiments, the thermal sensitivity of the imaging device (e.g., IR camera) is between 18 - 50 mK. This range allows for the detection of smaller temperature differences or less steep gradients, and thus, an imaging device with a thermal sensitivity range between 18 - 50 mK provides an enhanced ability to detect smaller defects.

[0040] Yet another parameter that can affect the detectability of defects is the speed of the heating element. That is, the speed and direction of the heating element relative to the stationary component is a parameter that affects detectability. In some embodiments, as described above, the heating element (e.g., an energized induction coil) moves or traverses relative to the stationary component. On the one hand, if the speed of the heating element is too slow, the component and its coating may reach or approach steady-state conditions. That is, if the speed of the heating element is too slow, the component becomes uniformly heated, which has an adverse effect on the detection of defects because the transient thermal gradients are "washed out" by the uniform heating of the component. On the other hand, if the speed of the heating element is too fast, the thermal contrast near the defect may not be generated to a sufficient degree for detection. Additionally, the faster the heating element traverses relative to the component, the faster the frame rate of the imaging device needs to be to capture the thermal gradients. In some example embodiments, the speed at which the heating element traverses or moves relative to the component for the detection of splashes and pits is between 2 - 5 cm / s.

[0041] Other parameters that can affect the detectability of defects include the heating rate and the heating duration. The heating rate is directly affected by the speed of the heating element relative to the component (see above) and the electrical characteristics of the current directed to the heating element (e.g., the frequency of the AC current). The heating duration depends on the size of the component (e.g., the thickness of the substrate of the component). If the heating duration is too long, the transient thermal gradient will be washed out. If the duration of heating the component is too fast, the imaging device may not be able to capture the gradient. Additionally, in some embodiments, the imaging device includes a detector that measures counts. The counts per period of time represent the temperature measurements of the target surface. In such embodiments, the component (e.g., a turbine blade with a TBC) can be heated at a rate of 45 counts / second - 300 counts / second. The heating rate is a function of the part thickness, material conductivity, and coating thickness variation. Generally, for example, thinner regions heat faster than thicker regions. The component can be cooled at a rate of 45 counts / second - 300 counts / second.

[0042] In another aspect, systems and methods for generating a single observation image from a plurality of captured images are provided. That is, all of the local thermal transients captured by the imaging device in a plurality of images or videos can be compiled into a single summary image. In particular, during the inspection of the coating of a component having a barrier coating, when the heating element traverses and applies heat to the component, the imaging device can capture an image of the component. For example, the imaging device can be an infrared imaging device. The captured images (e.g., collectively referred to as an IR video) are received by one or more processors of a computing system. The received images capture the component from the same angle. In response to the heating element sweeping across and heating the component, the received images also capture the thermal distribution of the component.

[0043] One or more processors are configured to generate a plurality of masked images using the received captured images. Specifically, in some implementations, in each captured image, a masking window is positioned adjacent to and in front of the heating element along the traversing direction. In other implementations, in each captured image, the masking window is positioned adjacent to and behind the heating element along the traversing direction. In other implementations, the masking window includes two sections, including a front section and a rear section. In such an implementation, the front section of the masking window in each captured image is positioned adjacent to and in front of the heating element along the traversing direction, and the rear section of the masking window in each captured image is positioned adjacent to and behind the heating element along the traversing direction. In such an implementation, the front section and the rear section can be discontinuous sections. When the heating element moves frame-by-frame or image-by-image relative to the component, the masking window moves or is positioned accordingly frame-by-frame or image-by-image. The masking window masks the pixels outside its perimeter. In this way, the pixels outside the masking window will be ignored.

[0044] Thermal data (e.g., temperature data) is applied to pixels within a masking window for each image. Thermal data can be applied to each pixel within a given masking window. Using the generated masking images, one or more processors determine the maximum or minimum value (e.g., maximum or minimum temperature value) for each pixel on the masking images. That is, all or some pixels can be represented in multiple masking images because the masking windows can be positioned so that they include some of the same pixels. One or more processors can consider the value (e.g., temperature value) of a particular pixel on multiple masking images and can determine the maximum or minimum value for that particular pixel. In other words, the maximum or minimum value associated with each pixel in the masking image is determined.

[0045] Once the maximum or minimum value is selected for each pixel on the masking image, a single observation image is generated. The pixels selected for inclusion in the two-dimensional single observation image are those representing the maximum or minimum value for their respective pixels. Therefore, the single observation image depicts the thermal response in an enhanced and easily analyzed manner. Furthermore, because the pixels are selected from those of the masking image, the heating element is absent from the single observation image. Therefore, while the imaging device captures the heating element traversing relative to the component as it applies heat to the component to capture the transient thermal response, the single observation image includes no or only negligible footprint of the heating element. This provides a clearer image and facilitates analysis of the component's thermal response.

[0046] System and method for automatically detecting defects in coatings of components

[0047] Now refer to Figure 1 and Figure 2 , Figure 1 A perspective view of a coating inspection system 100 according to one embodiment of the present disclosure is provided. Figure 2 Provided with Figure 1 2 is a schematic close-up cross-sectional view of a portion of a component 200 undergoing coating inspection of the system 100. Generally, the system 100 is operably configured to detect defects in a barrier coating of a component. For example, the system 100 is operable to detect defects in a thermal barrier coating (TBC) of a metal component of a gas turbine engine, such as a turbine blade or vane of a nozzle. Furthermore, the system 100 is configured to detect various types of coating defects, including but not limited to splatters, pits, delamination, and other types of cracks and surface imperfections. Although the component 200 is described herein as a metal turbine blade for an aircraft gas turbine engine, it should be understood that the system 100 described herein is not limited to detecting defects in turbine blades, but is configured to detect defects in other types of metal components that also have a barrier coating.

[0048] exist Figure 1In the figure, component 200 is shown as undergoing a coating inspection of system 100. For this embodiment, component 200 is a high-pressure turbine blade of an aero gas turbine engine. As Figure 2 shown, component 200 has a metallic structure 210. For example, metallic structure 210 can be formed of a nickel superalloy or other suitable high-temperature metallic material. Component 200 also has a metallic bond coat 212 and a thermal barrier coat 214. Metallic bond coat 212 is disposed between the outer surface 215 of metallic structure 210 and thermal barrier coat 214. Thus, thermal barrier coat 214 is the outermost or top coat of component 200. Thermal barrier coat 214 has an outer surface 216. Thermal barrier coat 214 can be a non-conductive thermal barrier coat. For example, thermal barrier coat 214 can be a ceramic thermal barrier coat. Metallic bond coat 212 promotes adhesion or bonding between thermal barrier coat 214 and metallic structure 210 of component 200. Metallic bond coat 212 can be applied to metallic structure 210 in any suitable manner. Similarly, thermal barrier coat 214 can be applied to metallic bond coat 212 in any suitable manner (e.g., by electron beam physical vapor deposition (EBPVD) coating process).

[0049] As Figure 2 further shown, component 200 defines one or more internal or inner channels 218, such as one or more internal cooling channels. Additionally, component 200 defines one or more cooling holes 220. One or more cooling holes 220 provide fluid communication between internal channels 218 of component 200 and the external environment. For example, when component 200 is positioned within the hot gas path of a gas turbine engine, cooling fluid can flow through internal channels 218 and downstream through cooling holes 220 and into the hot gas path. In this way, component 200 can be cooled during operation of the gas turbine engine.

[0050] Specifically returning to Figure 1 , system 100 will now be described in detail. For this embodiment, system 100 includes a heating system 110, a platform system 130, an air flow generator 140, an imaging system 150, and a computing system 160. By reference, Figure 1 system 100 defines a vertical direction V, a lateral direction L, and a transverse direction T. The vertical direction V, the lateral direction L, and the transverse direction T are mutually perpendicular and form an orthogonal direction system.

[0051] The heating system 110 of system 100 includes one or more heating elements 112, and one or more heating elements 112 are operatively configured to impart heat to the component undergoing inspection. For example, as Figure 1As shown, one or more heating elements 112 are configured to heat the component 200. For this embodiment, the one or more heating elements 112 include an electric heating coil 114. For example, the heating coil 114 may be formed of copper or another suitable conductive material. The heating coil 114 may include or form a vortex or spiral heating portion 116, for example, at its distal end. The spiral heating portion 116 defines a heating zone 118, and the size of the heating zone 118 is designed to receive the component 200. That is, the size of the spiral heating portion 116 of the heating coil 114 is designed such that the component 200 can be received within the heating zone 118. In this way, the heating coil 114 can completely surround or encircle the component 200. Assuming the use of multiple imaging devices, this can allow for simultaneous image capture of multiple sides of the component. In other embodiments, the heating coil 114 may have other suitable shapes or geometries for heating the component 200 during coating inspection.

[0052] Referring Figure 1 and 2 , the heating coil 114 is electrically connected to a power source 120. The power source 120 can be any suitable power source. For example, the power source 120 can be a battery, line voltage, some combination thereof, etc. When the heating coil 114 is energized by the current provided by the power source 120, heat radiates from the heating coil 114. The radiated heat can induce eddy currents in the metal structure 210 of the component 200. In this way, the heating coil 114 can inductively heat the component 200. Since the barrier coating 214 of the component 200 is a non-conductive coating in this exemplary embodiment, the eddy currents do not flow through the barrier coating 214. Heat radiates outward from the metal structure 210 and the metal bonding coating 212 through the barrier coating 214 and ultimately radiates to the exterior of the component 200, as Figure 2 shown. As will be explained in more detail herein, different thermal responses are generated due to the difference in the heat radiated or emitted outward from the non-defective regions 232 of the barrier coating 214 and the heat radiated from the defects 230 or defect regions in the barrier coating 214. The system 100 can sense or capture these transient thermal responses and accordingly detect defects in the barrier coating 214.

[0053] The heating system 110 further includes a servo motor 122. When commanded (e.g., by one or more electrical signals received from a control device), the servo motor 122 can move the heating coil 114 relative to the component 200. Thus, the heating coil 114 can be moved relative to the component 200. In this exemplary embodiment, the heating coil 114 can be moved in a transverse direction T1 relative to the stationary component 200. In Figure 1In this case, the transverse direction T1 extends along or is parallel to the vertical direction V. Thus, the heating coil 114 can inductively heat the component 200 when it traverses relative to or across the component 200 along the transverse direction T1. In this way, the entire length of the component 200 can be inductively heated. It should be understood that the transverse direction T1 does not need to be parallel to or extend along the vertical direction V, and can also extend along other directions. Notably, the heating coil 114 can traverse relative to the component 200 and apply heat to it without contacting the component 200.

[0054] By moving the heating coil 114 relative to the component 200 along the transverse direction T1, transient thermal gradients can be created and captured by the imaging system 150. The thermal gradients are transient because they are generated instantaneously or over a relatively short period of time when the heating coil 114 traverses and heats a particular region of the component 200. Thus, the transient thermal gradients appear and disappear relatively quickly. Therefore, the thermal response of the component is transient because the captured response is time-sensitive with respect to when the heating coil 114 traverses and heats the component 200.

[0055] In some alternative embodiments, the heating system 110 can be operably configured to generate a thermal gradient within the barrier coating 214 of the component 200 between the defective region 230 and the non-defective region 232. In such embodiments, various suitable types of heating elements can be used, including optical heating elements, laser heating elements, electromagnetic heating elements (e.g., microwave heating elements).

[0056] The platform system 130 of the system 100 includes a platform 132. For this embodiment, the platform 132 is a multi-axis platform that can move along multiple axes. In particular, for this embodiment, the platform 132 can be translated along the vertical direction V, the lateral direction L, and the transverse direction T. The platform system 130 includes a component holder 134 or bracket that is operable, for example, during inspection, to hold the component 200 in place. In some embodiments, the component 200 can be manually loaded into and / or unloaded from the component holder 134. In other embodiments, a robotic arm or other automated device can load the component 200 into and / or unload the component 200 from the component holder 134. For Figure 1 the illustrated embodiment, the component holder 134 is operably coupled to the platform 132 via a turntable 136. The turntable 136 is operable to rotate about a rotational axis (e.g., the longitudinal centerline LC). In this way, the component holder 134 and thus the fixed component 200 can be rotated about the rotational axis. Among other benefits, this can allow the component 200 to be oriented relative to the imaging device or the heating coil 114 during inspection.

[0057] In some embodiments, when commanded (e.g., by one or more electrical signals from a control device), the platform system 130 (e.g., via the multi-axis platform 132 and / or the turntable 136) is configured to move the component 200 relative to the heating coil 114. For example, the multi-axis platform 132 can initially position the component 200 relative to the heating coil 114 such that, for example, the component 200 is centered or substantially centered along the longitudinal axis LC defined by the helical heating portion 116 of the heating coil 114. In this manner, the heating coil 114 can sweep or traverse across the component 200 in a transverse direction T1 during an inspection process to inductively heat the component 200. The turntable 136 can be controlled to orient the component 200 to a desired orientation, e.g., for inspecting a particular side of the component 200. In some alternative embodiments, the platform system 130 can be configured to move the component 200 relative to the heating coil 114 (e.g., via the platform 132 and the turntable 136), where the heating coil 114 is held or controlled to remain in a fixed position. Thus, in some embodiments, the component 200 can be moved by the platform system 130 relative to a fixed heating coil 114.

[0058] In some embodiments, the system 100 optionally includes an airflow generator 140. For this embodiment, the airflow generator 140 is mounted to the platform system 130. However, in other embodiments, the airflow generator 140 is separate from the platform system 130. The airflow generator 140 is operable to, for example, pass, move, or otherwise direct air through, across, or around the component 200 when the heating coil 114 traverses and heats the component 200. For example, as Figure 2 shown, the airflow generator 140 can move air through one or more internal channels 218 of the component 200. Thus, the airflow generator 140 is in fluid communication (e.g., airflow communication) with the internal channels 218 of the component 200. For example, one or more conduits can fluidly couple the airflow generator 140 to the internal channels 218 of the component 200. The conduits can be internally routed through the platform 132, the turntable 136, and the component holder 134, or can be externally routed to the internal channels 218 of the component 200.

[0059] In some embodiments, the airflow generator 140 can be configured to pulse air through one or more internal channels 218 of the component 200. In this way, improved detectability of defects (e.g., spatter and pits) can be achieved, especially around functionally important features. Functionally important features of a component can include, but are not limited to, leading and / or trailing edges of blades or nozzles, tips of blades, regions near cooling holes, etc. The airflow generator 140 can be controlled to pulse a quantity of air at a predetermined frequency or interval. For example, the range of the predetermined frequency can be from 10 -2 to 10 2Hz. The frequency selected from this range can promote the enhancement of the transient thermal response of component 200. Additionally, the air flow generator 140 can be controlled to deliver a predetermined amount of air with each pulse. In some embodiments, ambient air can be drawn into the air flow generator 140 and pulsed into or through component 200. In other embodiments, the air flow generator 140 is in fluid communication with a pressurized air source (not shown). The air flow generator 140 can receive pressurized air from the pressurized air source and is capable of pulsing the pressurized air into or through component 200 at a predetermined frequency and amount.

[0060] As Figure 1 Further depicted in, the imaging system 150 of system 100 has one or more imaging devices or sensors. For this embodiment, the one or more imaging devices include imaging camera 152. In this example embodiment, the imaging camera 152 is an infrared (IR) camera. The imaging camera 152 is operably configured to capture multiple images (i.e., a collection of still images or video) of component 200 when the heating coil 114 heats component 200 along the traverse direction T1 and traverses relative to component 200, and in some cases, when the air flow generator 140 pulses air through the internal channel 218 of component 200. In this way, the imaging camera 152 can detect the transient thermal response of component 200. That is, the imaging camera 152 is configured to capture multiple images or video of multiple frames with the instantaneous temperature distribution of component 200 when the heating coil 114 traverses over component 200 and inductively heats component 200.

[0061] In some embodiments, the imaging camera 152 can be a mid-wavelength IR camera. The mid-wavelength IR camera can capture wavelengths in the range of approximately three to six microns (3 - 6 μm). Notably, with the mid-wavelength IR camera, the barrier coating 214 is transparent or substantially transparent. Thus, the mid-wavelength IR camera can be used to capture defects in the metal structure 210 and / or the metal bonding coating 212. In other embodiments, the imaging camera 152 can be a long-wavelength IR camera. The long-wavelength IR camera can capture wavelengths in the range of approximately six to fourteen microns (6 - 14 μm). With the long-wavelength IR camera, the barrier coating 214 is opaque or substantially opaque. Thus, the long-wavelength IR camera can be used to capture defects in the metal bonding coating 212 and the barrier coating 214. Additionally, in some embodiments, the imaging system 150 includes a mid-wavelength IR camera and a long-wavelength IR camera. In this way, the mid-wavelength IR camera can capture defects in the metal structure 210 and / or the metal bonding coating 212, while the long-wavelength IR camera can capture defects in the metal bonding coating 212 and the barrier coating 214 of the component 200. This can help determine which structure or coating initiated the defect, whether the defect propagated through the metal structure 210 or only through the coatings 212, 214, and generally can provide information useful for estimating the life of the component 200.

[0062] Additionally, in some example embodiments, the imaging camera 152 has a thermal sensitivity between 18 - 50 mK. This range allows for the detection of smaller temperature differences or less steep gradients, thus allowing for the detection of smaller defects. Additionally, in some example embodiments, the imaging camera 152 has a frame rate of at least 60 Hz. In some embodiments, the imaging camera 152 has a frame rate between 60 - 500 Hz. In some embodiments, the imaging camera 152 has a frame rate between 250 - 500 Hz. Such a frame rate can allow for the detection of smaller defects (e.g., defects less than 10 mils), as the thermal gradient changes near small defects tend to disappear more quickly. In some embodiments, the imaging camera 152 can detect defects or features as small as 80 microns (or approximately 0.003 inches).

[0063] The computing system 160 of the system 100 can include, for example, one or more processors and one or more memory devices embodied in one or more control or computing devices (see Figure 12)。One or more processors may include or may be any suitable processing device, such as a microprocessor, a microcontroller, an integrated circuit, a logic device, and / or other suitable processing devices. One or more memory devices may include one or more computer-executable or computer-readable media, including but not limited to non-transitory computer-readable media, RAM, ROM, hard disk drives, flash drives, and / or other memory devices. One or more memory devices may store information accessible by one or more processors, including computer-readable instructions executable by one or more processors. The instructions may be any instruction set that, when executed by one or more processors, causes the one or more processors to perform operations, such as any operations and functions that the one or more processors are configured to perform, such as activating and controlling various aspects of system 100. The instructions may be software written in any suitable programming language or may be implemented in hardware. Additionally or alternatively, the instructions may be executed in logically and / or virtually separate threads on one or more processors.

[0064] The memory device may store data accessible by one or more processors. For example, the data may include settings for thermal analysis components, thermal signatures, etc. The data may also include other data sets, parameters, outputs, information, etc. shown and / or described herein. One or more processors may communicate with a communication interface for communicating with, for example, other components of system 100. The communication interface may include any suitable components for interfacing with one or more networks or electronic components, including, for example, transmitters, receivers, ports, controllers, antennas, and / or other suitable components. The communication interface may be used to communicate with other electronic devices via one or more networks, such as local area networks (LANs), wide area networks (WANs), VHF networks, HF networks, Wi-Fi networks, WiMAX networks, gatelink networks, and / or any other suitable communication networks. The communication interface may communicate via one or more networks using a variety of communication protocols. The communication interface may include a data bus or a combination of wired and / or wireless communication links that communicatively couple one or more processors with other electronic devices.

[0065] In particular, one or more processors of computing system 160 may be communicatively coupled to various systems / devices of system 100. For example, in addition to other possible systems or their devices, one or more processors may be communicatively coupled to heating system 110, platform system 130, airflow generator 140, imaging system 150. One or more processors may be communicatively coupled to these various systems and / or their devices via one or more wired and / or wireless communication links.

[0066] System 100 may also include a user interface 170. The user interface 170 is provided for user control of the system 100. For example, the user interface 170 includes a plurality of user controls (not labeled). The user controls may include one or more of various electrical, mechanical, or electromechanical input devices, including rotary dials, buttons, and touchpads and / or screens. The user interface 170 may include one or more display devices 172, such as digital or analog display devices designed to provide feedback or results of an inspection process to the user.

[0067] Figure 3 A flowchart of an example method (300) is provided, where Figure 1 System 100 of may perform a coating inspection process on a component, for example to detect defects in its barrier coating. That is, after coating a component with a barrier coating, the component and its barrier coating can be inspected by the system 100 in Figure 3 the manner described in. For purposes of illustration and discussion, Figure 3 the actions are depicted as being performed in a particular order. Those of ordinary skill in the art using the disclosure provided herein will understand that the various actions of any method disclosed herein can be modified in various ways without departing from the scope of the disclosure. Various features of the system 100 and component 200 will be referenced, and thus, will generally reference Figure 1 、 2 and 3 and other specifically pointed out figures.

[0068] At (302), the method (300) includes positioning a component having a barrier coating relative to a heating element. For example, a component 200 having a barrier coating 214 may be positioned relative to the heating element 112 of the heating system 110. In some embodiments, the component 200 may be manually loaded into the component holder 134 of the platform system 130. In other embodiments, a robotic arm or other automated device may load the component 200 into the component holder 134. Once the component 200 is secured in the component holder 134, the turntable 136 may rotate the component 200 about its axis of rotation to orient the component 200 relative to the imaging camera 152 of the imaging system 150. For example, it may be necessary to orient a particular side (e.g., the pressure or suction side of a turbine blade) or edge (e.g., the leading or trailing edge of a turbine blade) of the component 200 relative to the imaging camera 152.

[0069] At (304), method (300) includes traversing a heating element relative to a component having a barrier coating. For example, one or more processors of computing system 160 may cause heating element 112 to traverse relative to component 200 along a traverse direction T1. For example, in response to receiving an input (e.g., a user input or an input from a sensing device indicating that component 200 is in a position for inspection and that inspection of component 200 is to begin), one or more processors of computing system 160 may cause servo motor 122 to move heating element 112 along traverse direction T1, which is along the Figure 1 vertical direction V in

[0070] In this way, when component 200 is held in place by platform system 130, heating element 112 traverses relative to component 200. Heating element 112 may traverse relative to component 200 at any suitable speed, depending on the thermal output of heating element 112 and the ability of imaging system 150 to capture the thermal response of component 200. As an example, the traverse speed of heating element 112 relative to component 200 may be set such that heating element 112 traverses the entire vertical length of component 200 in thirty seconds (30 s). As another example, the speed at which heating element 112 traverses or moves relative to component 200 for defect detection is between 2 - 5 cm / s. Figure 2 As shown, heat radiates outwardly toward outer surface 216 of barrier coating 214 and into the external environment. A transient thermal gradient is created due to the difference in heat radiating outwardly from non - defect regions 232 of barrier coating 214 and from defects 230 in barrier coating 214. Imaging camera 152 may capture these transient thermal gradients or responses and detect defects in barrier coating 214 based on this transient thermal response.

[0071] At (308), optionally, method (300) includes causing a gas flow pulse to pass through an internal channel defined by the component while the heating element traverses relative to the component and heat is applied thereto. For example, as shown in Figure 1 and 2As shown, in some embodiments, system 100 includes an airflow generator 140. Component 200 may be positioned on platform system 130 such that airflow generator 140 is in fluid communication with internal passage 218 of component 200, e.g., by fluidly connecting airflow generator 140 and one or more internal passages 218 of component 200 through one or more ducts. In such embodiments, one or more processors of computing system 160 are configured to cause airflow generator 140 to pulse an airflow through one or more internal passages 218 of component 200 when heating element 112 traverses and applies heat to component 200. The pulsed airflow may exit through one or more apertures 220 that are in fluid communication with one or more internal passages 218. In this way, improved detectability of defects (e.g., pits and splashes) can be achieved, especially around functionally important features. As previously mentioned, airflow generator 140 can be controlled to pulse a quantity of air at a predetermined frequency or interval, and each pulse provides a predetermined quantity of air. For example, the range of the predetermined frequency can be from 10 -2 to 10 2 Hz.

[0072] At (310), method (300) includes capturing a plurality of images of the component with an imaging device when a heating element traverses and applies heat to the component, wherein the plurality of captured images may indicate the thermal response of the component to the applied heat. Thus, (304), (306), and (310) may occur simultaneously. In some embodiments, a plurality of images may be captured when a heating element traverses and applies heat to the component while an airflow generator pulses a quantity of air into an internal passage of the component. Thus, in some embodiments, (304), (306), (308), and (310) may occur simultaneously. When heating element 112 traverses and applies heat to component 200, imaging camera 152 of imaging system 150 can be used to capture a plurality of images of component 200. Imaging camera 152 may remain in a fixed position while it captures the plurality of images.

[0073] In some embodiments, imaging camera 152 of imaging system 150 may be a mid-wavelength IR camera that is operable to capture wavelengths in the range of approximately three to six microns (3 - 6 μm). Mid-wavelength IR cameras are particularly suitable for capturing defects in metal structure 210 ( Figure 2 ) and / or metal bonding coating 212 ( Figure 2 ) of component 200. In other embodiments, imaging camera 152 may be a long-wavelength IR camera that is operable to capture wavelengths in the range of approximately six to fourteen microns (6 - 14 μm). Long-wavelength IR cameras are particularly suitable for capturing metal bonding coating 212 ( Figure 2 ) and barrier coating 214 ( Figure 2) defects.

[0074] Figures 4 - 7 Provides a schematic view of the heating element 112 traversing relative to the component 200 when heat is applied to it (i.e., to the component 200) by the heating element 112. In Figure 4 , the heating element 112 is in a first position, which in this example is a position vertically above the component 200 along the vertical direction V. In this exemplary embodiment, the first position is the starting position. In order to capture an image of the transient thermal characteristics or response of the component 200 with the imaging camera 152 ( Figure 1 ), the computing system 160 of the system 100 ( Figure 1 ) causes the heating element 112 to traverse relative to the component 200 and apply heat to it. More specifically, one or more processors of the computing system 160 ( Figure 1 ) cause the heating element 112 to heat the component 200. Heat H is shown radiating from the heating element 112. The heat H radiating from the heating element 112 imparts thermal energy or heat H to the component 200. Utilizing the heat H radiating from the heating element 112, one or more processors of the computing system 160 ( Figure 1 ) cause the heating element 112 to traverse relative to the component 200 along the traversing direction T1, which in this example is downward along the vertical direction V.

[0075] Figure 5 , 6 and 7 depict the heating element 112 at various positions along its traversing path. In Figure 5 , the heating element 112 is in a second position, i.e., a position below the first position along the vertical direction V. In Figure 6 , the heating element 112 is shown in a third position, i.e., a position below the second position along the vertical direction V. In Figure 7 , the heating element 112 is shown in a fourth position, i.e., a position below the third position along the vertical direction V. At the fourth position, the heating element 112 has completed traversing relative to the element 200 along the traversing direction T1. In this exemplary embodiment, the fourth position is the starting position. The heating element 112 can move or traverse relative to the component 200 at a constant or substantially constant speed along the traversing direction T1. When the heating element 112 moves along the traversing direction T1 (e.g., from the first position ( Figure 4 ) to the fourth position ( Figure 7 )), the imaging camera 152 ( Figure 1 ) can capture multiple images of the component 200. Images of the component 200 can be captured at any suitable capture rate (e.g., any suitable number of frames per second).

[0076] When the heating element 112 traverses relative to the component 200 (e.g., from the position shown in Figure 4 toFigure 7 at the position shown) and applying heat H thereto, the imaging camera 152( Figure 1 ) captures the transient thermal response of the component 200. More specifically, due to the movement of the heating element 112 relative to the component 200 and the application of heat H to the component 200, a transient thermal gradient is generated between the non-defective region 232( Figure 2 ) of the component 200 and the defect 230( Figure 2 ). By using the air flow generator 140 to pulse an air flow through the internal passage 218 of the component 200, the transient thermal gradient can be enhanced (i.e., made steeper and thus more apparent to the imaging camera 152( Figure 1 )).

[0077] In particular, as best shown in Figure 8 , Figure 8 a close-up view depicting the heating element 112 traversing and heating the component 200 is shown, with a transient thermal gradient generated adjacent to and in front of the heating element 112 along the traversing direction Tl, which in this example is vertically downward V below the heating element 112. It is noted that when heat H is applied to the component 200, the non-defective region 232 and the defective region 230 of the component 200 produce different thermal signatures. That is, the non-defective region 232 and the defective region 230 have different thermal emissivities. In addition, each type of defect can have a recognizable thermal signature or emissivity. For example, the non-defective region 232 of the component 200 can produce a first thermal emissivity or first thermal signature as represented by the hatched pattern in Figure 8 . The pit 230A or void defect can produce a second thermal emissivity or second thermal signature as represented by the vertical line pattern in Figure 8 . In addition, the spatter 230B can produce a third thermal emissivity or third thermal signature as represented by the horizontal line pattern in Figure 8 . Other types of defects can also have associated thermal emissivities or signatures. The imaging camera 152 can capture these different transient thermal responses, and the computing system 160 can analyze the coating of the component 200 based on these different thermal responses captured in the image.

[0078] At (312), in some embodiments, the method (300) includes generating a single image from a plurality of captured images, where the single image indicates one or more detected coating defects in the barrier coating of the component. For example, one or more processors of the computing system 160 can generate a single image from a plurality of captured images captured by the imaging camera 152, the single image indicating one or more detected coating defects in the barrier coating of the component. In some embodiments, as in Figure 12As shown, one or more memory devices 166 of computing system 160 may store instructions 166A. The instructions 166A may include a single image generator component 165. When the single image generator component 165 is executed by one or more processors 164, the captured images are used to generate a single image that generally indicates defects in the barrier coating of the component or defects in the component.

[0079] Figure 9 A schematic diagram of a single image 250 generated from multiple captured images is provided. Figure 9 The single image 250 may be generated as a result of a single image generator component 165 ( Figure 12 ) of one or more processors 164 ( Figure 12 ) executing the instructions 166A ( Figure 12 ). As Figure 9 shown, the single image 250 indicates a coating defect 230 detected in the barrier coating 214 of the component 200. In particular, the single image 250 indicates that the component 200 has one or more pits 230A and one or more splashes 230B. The component and its thermal response to being heated by the heating element 112 when traversed relative to the heating element 112 are reflected in the single image 250 by a plurality of pixels. As will be explained in more detail herein, each pixel in the single image 250 representing a portion of the component 200 may indicate the maximum temperature captured by the imaging camera 152 for that particular pixel. That is, considering all temperature data received for all captured images, each pixel of the single image 250 represents the maximum sensed temperature for that pixel.

[0080] Notably, the single image 250 is generated from captured images that all depict the component 200 in the same orientation or position relative to the imaging camera 152. That is, the single image 250 is generated from images that all capture the same perspective of the component 200. For example, in the case where the component is a high-pressure turbine blade of a gas turbine engine, a first single image may be generated for the first side of the blade (e.g., the pressure side of the blade) based on capturing a plurality of images of the first side, and a second single image may be generated for the second side of the blade (e.g., the suction side of the blade) based on capturing a plurality of images of the second side. It should be understood that other single images may also be generated for other sides or perspectives of the component 200.

[0081] An example manner in which a single image may be generated by one or more processors of the computing system 160 using multiple captured images will be described in detail herein with reference to Figures 13 - 22 and the accompanying text.

[0082] At (314), method (300) includes detecting one or more coating defects in a barrier coating of a component at least in part based on a thermal response of the component captured in a plurality of images. For example, in some embodiments, one or more processors of computing system 160 ( Figure 1 ) use a single image generated at (312) to detect one or more coating defects in a barrier coating of a component, the single image being generated using a plurality of captured images. In some embodiments, computing system 160 includes a computer vision system. Thus, as Figure 12 shown, instructions 166A stored on one or more memory devices 166 may include vision system components 167. Vision system components 167 may include signal processing features as well as machine learning algorithms. For example, the machine learning algorithm may be embodied in a convolutional neural network. Generally, when vision system components 167 are executed by one or more processors 164, one or more defects are typically detected in the barrier coating or the component of the component, and the detected defects can be analyzed so that various characteristics of the detected defects can be determined. Vision system components 167 may include defect detector components 167A. When defect detector components 167A are executed by one or more processors 164, one or more defects are typically detected in the barrier coating or the component of the component.

[0083] In some embodiments, when detecting one or more coating defects in a barrier coating of a component at least in part based on a thermal response of the component captured in an image at (314), one or more processors of computing system 160 are configured to identify one or more regions of the barrier coating having a transient thermal response outside a predetermined range. In such an embodiment, one or more regions of the barrier coating having a transient thermal response outside a predetermined range are identified as one or more coating defects of the barrier coating.

[0084] In some exemplary embodiments, the transient thermal response of a component may be defined according to a transient thermal gradient (e.g., the ratio of a temperature difference to a distance between two points, or equivalently, the temperature change within a given length). By way of example, Figure 10A close-up view of a single image 250 is provided. The single image 250 includes a plurality of pixels P. A small sample size of the pixels is specifically marked, including the first, second, third, fourth, fifth, sixth, seventh, eighth, ninth, tenth, eleventh, twelfth, thirteenth, fourteenth, fifteenth, and sixteenth pixels, labeled as P1, P2, P3, P4, P5, P6, P7, P8, P9, P10, P11, P12, P13, P14, P15, and P16, respectively. In this example, the pixel P is square, but in other embodiments, the pixel P may be other suitable shapes. In this example, to identify one or more regions of the barrier coating having a transient thermal response outside a predetermined range, one or more processors of the computing system 160 are configured to determine a plurality of transient thermal gradients.

[0085] As Figure 10 shown, the predetermined length or distance between two points may be the distance between the center of one pixel and the center of an adjacent pixel. Other predetermined lengths associated with determining the thermal gradient are possible. For example, the predetermined length or distance between two points may be the distance between the center of one pixel and the center of a pixel separated by five pixels. It should be understood that these are exemplary predetermined lengths. In this exemplary embodiment, for each pixel P, a transient thermal gradient is determined for each adjacent pixel. For example, a first transient thermal gradient G1 is determined between the first pixel P1 and the second pixel P2, and a second transient thermal gradient G2 is determined between the first pixel P1 and the fifth pixel P5. It should be understood that transient thermal gradients may be determined for the pixels above and to the left of the first pixel P1 in Figure 10 the figure. A small sample size of the determined thermal gradients is specifically marked, including the first, second, third, fourth, fifth, sixth, seventh, eighth, ninth, tenth, eleventh, twelfth, thirteenth, fourteenth, fifteenth, sixteenth, seventeenth, eighteenth, nineteenth, twentieth, twenty-first, twenty-second, twenty-third, and twenty-fourth transient thermal gradients, labeled as G1, G2, G3, G4, G5, G6, G7, G8, G9, G10, G11, G12, G13, G14, G15, G16, G17, G18, G19, G20, G21, G22, G23, and G24, respectively.

[0086] Using the determined thermal gradients, one or more processors of the computing system 160 are configured to determine whether one or more of the determined transient thermal gradients are outside a predetermined range, e.g., outside the range of values associated with transient thermal gradients expected to be associated with non-defective regions of the component. Each transient thermal gradient may be compared to the predetermined range. For example, in Figure 10Among them, it is determined whether each of the transient thermal gradients G1, G2, G3, G4, G5, G6, G7, G8, G9, G10, G11, G12, G13, G14, G15, G16, G17, G18, G19, G20, G21, G22, G23, and G24 (and so on for thermal gradients not shown) falls within a predetermined range. In this example, one or more processors of the computing system 160 determine that G4, G6, G9, G12, G16, G18, G19, and G20 are outside the predetermined range and the remaining transient thermal gradients are not outside the predetermined range. Thus, one or more processors of the computing system 160 can determine or identify pixels P6, P7, P10, and P11 as areas that are defects in the barrier coating of the component. Other areas can be identified as defects in the same manner as described above.

[0087] In some embodiments, the predetermined range is one of a plurality of predetermined ranges. Each predetermined range can be associated with an area or location of the component. For example, one predetermined range can be associated with the leading edge of the component, one predetermined range can be associated with the area around the cooling holes, one predetermined range can be associated with the trailing edge of the component, etc. In such embodiments, the determined thermal gradient can be compared with the predetermined range among the plurality of predetermined ranges that is associated with the area or location corresponding to the position of the pixel under consideration.

[0088] In some other exemplary embodiments, the transient thermal response of the component can be defined according to the transient emissivity. As an example, Figure 11 Another close-up view of a portion of the single image 250 is provided. As with Figure 10 the single image 250, Figure 11 the single image 250 includes a plurality of pixels P, including first, second, third, fourth, fifth, sixth, seventh, eighth, ninth, tenth, eleventh, twelfth, thirteenth, fourteenth, fifteenth, and sixteenth pixels, labeled P1, P2, P3, P4, P5, P6, P7, P8, P9, P10, P11, P12, P13, P14, P15, and P16 respectively. In this example, the pixel P is square, but in other embodiments, the pixel P can be other suitable shapes. In this example, in order to identify one or more areas of the barrier coating having a transient thermal response outside the predetermined range, one or more processors of the computing system 160 are configured to determine the thermal emissivity of the component embodying each pixel P. As described above, considering all the temperatures captured in multiple images for a particular pixel, each pixel P can indicate the maximum temperature captured for that particular pixel.

[0089] As Figure 11As shown, a transient emissivity is determined for each pixel P. For example, a first emissivity R1 is determined for a first pixel P1, a second emissivity R2 is determined for a second pixel P2, and so on for each pixel P to determine the transient emissivity. In this way, first, second, third, fourth, fifth, sixth, seventh, eighth, ninth, tenth, eleventh, twelfth, thirteenth, fourteenth, fifteenth, and sixteenth emissivities can be determined for their associated pixels, as Figure 11 shown. The emissivities are labeled R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, R12, R13, R14, R15, and R16, respectively.

[0090] Using the determined emissivities, one or more processors of the system 160 are configured to determine whether one or more of the determined emissivities are outside a predetermined range, e.g., outside a range of values associated with transient heat emissions expected to be associated with non-defective regions of the component. Each transient emissivity can be compared with the predetermined range. For example, in Figure 11 it is determined whether one or more of the transient emissivities R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, R12, R13, R14, R15, and R16 (and so on for emissivities not shown) fall within the predetermined range. In this example, one or more processors of the system 160 determine that the emissivities R6, R7, and R11 are outside the predetermined range and the remaining transient emissivities are not outside the predetermined range. Thus, one or more processors of the system 160 can identify or determine the pixels P6, P7, and P11 as regions that are defects in the barrier coating of the component. Other regions can be identified as defects in the same manner as described above.

[0091] In some embodiments, the predetermined range is one of a plurality of predetermined ranges. Each predetermined range can be associated with a region or location of the component. For example, one predetermined range can be associated with the leading edge of the component, one predetermined range can be associated with the region around a cooling hole, one predetermined range can be associated with the trailing edge of the component, etc. In such embodiments, the determined emissivity can be compared with the predetermined range among the plurality of predetermined ranges that is associated with the region or location corresponding to the position of the pixel under consideration.

[0092] In some embodiments, when detecting one or more coating defects in the barrier coating of a component at (314) at least in part based on the thermal response of the component captured in an image, one or more processors of the computing system 160 are configured to determine a rate of change of temperature associated with a pixel or group of pixels of the captured image. Notably, defects can be detected both during heating and cooling of the component. Thus, a heating rate associated with a pixel can be determined and / or a cooling rate associated with a pixel can be determined. The determined heating rate of the pixel or group of pixels can be compared to a predetermined heating rate. The predetermined heating rate can be a heating rate associated with an expected heating rate of a non-defective region of the component. Thus, if the determined heating rate of the pixel or group of pixels is outside the predetermined heating rate, the pixel or group of pixels outside the predetermined heating rate can be determined or identified as a defect (or part of a defect) in the barrier coating. Additionally, for a pixel or group of pixels having a heating rate determined to be outside the predetermined heating rate, the determined heating rate of the pixel or group of pixels can be used to classify the defect associated therewith. For example, various defects (such as splashes, pits, delaminations, etc.) can have corresponding expected heating rate ranges. One or more processors can determine which heating rate range the determined heating range falls into and can classify the type of defect accordingly.

[0093] Additionally or alternatively, the determined cooling rate of the pixel or group of pixels can be compared to a predetermined cooling rate. The predetermined cooling rate can be a cooling rate associated with an expected cooling rate of a non-defective region of the component. Thus, if the determined cooling rate of the pixel or group of pixels is outside the predetermined cooling rate, the pixel or group of pixels outside the predetermined cooling rate can be determined or identified as a defect (or part of a defect) in the barrier coating. Additionally, for a pixel or group of pixels having a cooling rate determined to be outside the predetermined cooling rate, the determined cooling rate of the pixel or group of pixels can be used to classify the defect associated therewith. For example, various defects (such as splashes, pits, delaminations, etc.) can have corresponding expected cooling rate ranges. One or more processors can determine which cooling rate range the determined cooling range falls into and can classify the type of defect accordingly.

[0094] Figure 12A graph depicting the time-temperature curve of a pixel according to an embodiment of the present disclosure is provided. As shown, when heat is applied to the component via the traversing heating element, the portion of the component associated with the pixel starts to rise at t = 0 seconds. At approximately t = 5 seconds, the pixel reaches the peak amplitude or peak temperature. After reaching the peak amplitude, when the heating element is away from the position of the component associated with the pixel, the position of the component corresponding to the pixel starts to cool. One or more processors can generate a time-temperature graph for each pixel or group of pixels of the captured image.

[0095] As described above, one or more processors can determine the heating rate associated with the pixel. The heating rate can be determined based on the instantaneous temperature of the pixel captured in multiple images and the frame rate of the imaging device. The heating rate of the pixel depends on the material properties of the component and whether there are defects at the position of the component associated with the pixel. In some embodiments, the heating rate can be determined as the average heating rate over a predetermined time period. As an example, the predetermined time period can be the time period from when the pixel exceeds the temperature threshold relative to its ambient temperature to when the pixel reaches the peak amplitude (e.g., from time t = 0 seconds to time t = 5 seconds in Figure 12 ). As another example, the predetermined time period can be a predefined time period during which the temperature of the portion of the component associated with the pixel rises. The heating rate can be determined and compared with the predetermined heating rate range as described above. When the pixel has a determined heating rate within the predetermined heating rate range, the position of the component associated with the pixel is identified as a non-defective part or region of the component. When the pixel has a determined heating rate outside the predetermined heating rate range, the position of the component associated with the pixel is identified as a defect or defect region of the component. Additionally, when the pixel has a determined heating rate outside the predetermined heating rate range, the defect type can be classified based on the determined heating rate, for example, in the above-described manner.

[0096] Additionally or alternatively, one or more processors can determine the cooling rate of the portion of the component associated with the pixel. The cooling rate can be determined based on the instantaneous temperature of the pixel captured in multiple images and the frame rate of the imaging device. The cooling rate of the pixel depends on the material properties of the component and whether there are defects at the position of the component associated with the pixel. In some embodiments, the cooling rate can be determined as the average cooling rate over a predetermined time period. As an example, the predetermined time period can be the time period from when the pixel reaches the peak amplitude to when the pixel reaches a temperature outside a predefined margin of the peak amplitude (e.g., in Figure 12the time period from time t = 5 seconds to time t = 16 seconds). As another example, the predetermined time period can be some other pre-defined time period. The cooling rate can be determined and compared with the predetermined cooling rate range as described above. When a pixel has a determined cooling rate within the predetermined cooling rate range, the location of the component associated with the pixel is identified as a non-defective part or region of the component. When a pixel has a determined cooling rate outside the predetermined cooling rate range, the location of the component associated with the pixel is identified as a defect or defective region of the component. Additionally, when a pixel has a determined cooling rate outside the predetermined cooling rate range, the defect type can be classified based on the determined cooling rate, for example, in the manner described above.

[0097] It should be noted that the peak amplitude associated with a pixel can correspond to a measure of the defect size or be a measure of the defect size. The larger the amplitude of the pixel, the larger the defect, and conversely, the smaller the amplitude of the pixel, the smaller the defect. Thus, in some embodiments, the defect size can be determined at least in part based on the amplitude of the pixel on its determined time-temperature curve. Additionally, in some embodiments, if the peak amplitude associated with a pixel is below an amplitude threshold (i.e., below a temperature threshold), the heating and / or cooling rate of the pixel is not determined because the pixel is not or is likely not associated with a defect. This can save valuable computing resources of one or more processors.

[0098] At (316), method (300) includes analyzing coating defects in the detected component. For example, one or more processors of computing system 160 can utilize the single image generated at (312) to analyze the detected defects in the component. In some embodiments, as Figure 12 shown, vision system component 167 includes defect analyzer component 167B. When defect analyzer component 167B is executed by one or more processors 164, the defects detected at (314) can be analyzed, and thus various characteristics of the detected defects can be determined. In some embodiments, defect detector component 167A and defect analyzer component 167B can be combined into a single component or instruction set.

[0099] In some embodiments, when analyzing defects in the detected component at (316), one or more processors of the computing system 160 are configured to determine one or more characteristics associated with the detected defect or defect region identified at (314). For example, one or more processors of the computing system 160 can be configured to determine the number of one or more coating defects in the identified barrier coating. That is, the total number of defects identified in the coating or component can be determined. The number of identified defects can represent the total number of defects identified in a single image. Since a single image may only capture one side or perspective of the component, it can be understood that the number of defects in other single images generated for other perspectives or sides of the component need to be added together to determine the total number of defects in the barrier coating of the component. For example, in the case where the component is a high-pressure turbine blade of a gas turbine engine, the number of defects identified in a first single image generated for the first side of the blade (e.g., the pressure side of the blade) will need to be added to the number of defects identified in a second single image generated for the second side of the blade (e.g., the suction side of the blade) to determine the total number of defects in the component.

[0100] One or more processors of the computing system 160 can be configured to also determine other characteristics associated with the detected defect. For example, one or more processors of the computing system 160 can be configured to determine the depth or height of the identified coating defect. Referring again to Figure 2 , determining the depth D1 of a defect (e.g., pit 230A) can provide information about the severity of the defect. In particular, determining the depth D1 of the defect can provide information about whether the metal structure 210 or bond coat 212 of the component 200 is exposed to the external environment due to the defect or whether the defect is contained within the barrier coating 214. Additionally, the defect depth can provide information about errors or problems with the coating machine or process. In some embodiments, the depth Dl can be defined as the distance from the outer surface 216 of the barrier coating 214 to the deepest part of the defect, as Figure 2 shown. In other embodiments, the depth D1 can be defined as the distance from the outer surface 216 of the barrier coating 214 to the average depth of the defect.

[0101] Determining the height E1 of a defect (e.g., spatter 230B) can also be useful. For example, the height E1 of the defect can provide information about errors or problems with the coating machine or process, and can provide insights into the likelihood that the spatter will come off and the size of the void that would result if the spatter detached from the component, for example, during engine operation. In some embodiments, the height E1 can be defined as the distance from the outer surface 216 of the barrier coating 214 to the apex of the defect, as Figure 2As shown. In other embodiments, the height E1 can be defined as the distance from the outer surface 216 of the barrier coating 214 to the average height of the defect.

[0102] The depth and / or height of the defect can be determined by one or more processors of the computing system 160 based on the thermal response of the component captured in a single image. For example, a defect with a greater depth may exhibit a higher thermal emissivity than a defect with a shallower depth. Thus, the emissivity represented by the pixels of a single image can be correlated with the depth (e.g., via a look-up table). Additionally, a defect with a greater height may exhibit a lower thermal emissivity than a defect with a lower height. Thus, the emissivity represented by the pixels of a single image can be correlated with the height (e.g., via a look-up table).

[0103] One or more processors of the computing system 160 can also be configured to determine the area fraction or percentage of each of the coating defects of the identified barrier coating. That is, the fraction of the area of a given defect or defect region relative to the total surface area of the component (or the total surface area of the side of the component depicted in a single image) can be determined. As an example, the number of pixels associated with the defect can be compared to the total number of pixels in a single image representing a portion of the component. The area fraction of the defect can also be determined in other suitable ways. Additionally, one or more processors can be configured to determine the total area fraction of the portion of the component represented in a single image, for example, by adding together all the area fractions associated with the identified defects and comparing the sum to the total surface area of the portion of the component represented in the single image. Further, in some embodiments, one or more processors can be configured to determine the total area fraction of the component, for example, by adding together all the area fractions associated with the identified defects and comparing the sum to the total surface area of the component. To determine the total area fraction of the component associated with the identified defects, it should be understood that the area fractions determined for defects in other generated single images (e.g., a single image representing the other side of the component) will be considered when determining the total area fraction.

[0104] In some embodiments, when analyzing defects in the detected component at (316), one or more processors of the computing system 160 are configured to classify the defects into categories or types of defects, such as pits or splashes. In some embodiments, one or more processors of the computing system 160 are configured to classify the identified defects at least in part based on the thermal response of the identified defects. For example, as described above, non-defective regions and defects of a component have different emissivities, and the pixels of the component represent this fact. Additionally, certain defects produce emissivities within an identifiable range. For example, a pit can produce an emissivity within a first predetermined range, a splash can produce an emissivity within a second predetermined range, and so on for other types of defects. Thus, the emissivity of each defect can be used to classify the type of the identified defect. Each defect can be classified based on the average emissivity represented by the pixels associated with a given defect and / or based on the pixels associated with the defect having the maximum or minimum emissivity.

[0105] Additionally, the thermal gradient determined between adjacent pixels can also be used to classify the defects. For example, a pit can produce a gradient having a steepness or slope within a first predetermined range, a splash can produce a gradient having a steepness or slope within a second predetermined range, and so on for other types of defects. In some embodiments, each defect can be classified based on the average slope or steepness of all thermal gradients extending from the pixels representing non-defective regions and the pixels forming a part of the perimeter of the identified defect (e.g., Figure 10 the average steepness of the thermal gradients G4, G6, G9, G12, G16, G18, G19, G20 in ). In other embodiments, each defect can be classified based on the steepest and / or lowest slope considering all thermal gradients extending from the pixels representing non-defective regions and the pixels forming a part of the perimeter of the identified defect.

[0106] In some other embodiments, when analyzing defects in the detected component at (316), one or more processors of the computing system 160 are configured to classify the defects into categories or types of defects at least in part based on one or more determined characteristics associated with the defects. For example, the depth and / or height of a particular defect can be used to classify the defect. For example, a defect having a depth within a predetermined depth range can be classified as a pit, a defect having a height within a predetermined height range can be classified as a splash, and so on for other types of defects. In some embodiments, when analyzing defects in the detected component at (316), one or more processors of the computing system 160 are configured to classify the defects into categories or types of defects at least in part based on one or more determined characteristics associated with the defects and the thermal response of the identified defects.

[0107] At (318), method (300) includes determining whether the barrier coating of the component is an acceptable barrier coating. For example, on the one hand, when the barrier coating of the component passes a combination of all or some of the predefined criteria, the barrier coating is determined to be acceptable. On the other hand, when the barrier coating of the component does not pass a combination of all or some of the predefined criteria, the barrier coating is determined to be unacceptable.

[0108] In some embodiments, one or more processors of computing system 160 are configured to determine whether the barrier coating of the component is an acceptable barrier coating based on at least one of the following comparisons: comparison of the number of one or more coating defects of the identified barrier coating with a number threshold; comparison of the depth of each of the one or more coating defects of the identified barrier coating with a depth threshold; comparison of the area fraction of the one or more coating defects of the identified barrier coating with an area fraction. In some embodiments, the barrier coating must pass all the comparisons. In other embodiments, the barrier coating must pass some combination thereof, such as two out of three comparisons.

[0109] In addition to or instead of the comparisons mentioned above, in some embodiments, one or more processors of computing system 160 are configured to determine whether the barrier coating of the component is an acceptable barrier coating based on the number of defects classified as a particular type of defect exceeding a number threshold, an area fraction threshold, etc. For example, if the number of pits exceeds the pit number threshold, the barrier coating will be determined to be unacceptable. Other predefined criteria for determining whether the barrier coating is acceptable are also possible. One or more processors of computing system 160 can automatically determine whether the barrier coating is acceptable without any manual visual inspection of the component.

[0110] At (320), method (300) includes displaying information associated with the inspection of the component. For example, one or more processors of computing system 160 can cause display device 172 to display information associated with the inspection of the component. Various types of information can be displayed. For example, the result of the inspection process can be displayed on display device 172. For example, a graphic on display device 172 can indicate whether the barrier coating of the component is acceptable or unacceptable. In addition, the determined characteristics of the detected defects can be displayed on display device 172. For example but not limited to, the number or total number of the identified defects can be displayed, the total area fraction of the identified defects can be displayed, the depth of various defects can be displayed, and the height of various defects can be displayed. Other characteristics associated with the identified defects can also be displayed.

[0111] In addition, a single image generated at (312) can be displayed on the display device 172. The displayed single image can indicate the thermal response or characteristics of the component 200 in response to the heating element 112 traversing and applying heat to the component 200. When displaying the single image, characteristics associated with defects identified in the single image can also be displayed. In addition, other single images generated for other perspectives of the component can be displayed on the display device 172. The user interface 170 provides a means for scrolling between the generated single images. When a particular single image is displayed on the display device 172, characteristics associated with defects identified in that particular single image can also be displayed.

[0112] Figure 12 A block diagram of the computing system 160 is provided. The computing system 160 can include one or more computing devices 162, which can be used to implement the methods and systems described herein according to example embodiments of the present disclosure. The computing device 162 is one example of a suitable computing device for implementing the computing elements described herein.

[0113] As previously described, the computing device 162 can include one or more processors 164 and one or more memory devices 166. The one or more processors 164 can include any suitable processing device, such as a microprocessor, a microcontroller, an integrated circuit, a logic device, or other suitable processing device. The one or more memory devices 166 can include one or more computer-readable media, including but not limited to non-transitory computer-readable media, RAM, ROM, hard disk drives, flash drives, and other memory devices, such as one or more buffer devices.

[0114] The one or more memory devices 166 can store information accessible by the one or more processors 164, including computer-readable instructions 166A executable by the one or more processors 164. The instructions 166A can be any instruction set that, when executed by the one or more processors 164, causes the one or more processors 164 to operate, such as, among other operations, causing the heating element to traverse and apply heat to the component while traversing the component, causing the air flow generator to pulse air into the internal channels of the component, causing a single image to be generated from a plurality of captured images, and / or causing the vision system to detect and analyze the identified defects. The instructions 166A can be software written in any suitable programming language or can be implemented in hardware. In some embodiments, the instructions 166A can be executed by the one or more processors 164 to cause the one or more processors 164 to operate.

[0115] The memory device 166 may also store data 166B that can be accessed by the processor 164. For example, the data 166B may include images captured by the imaging device, baseline data, model data, logic data, etc., as described herein. According to an example embodiment of the present disclosure, the data 166B may include one or more tables, functions, algorithms, models, equations, etc.

[0116] One or more computing devices 162 may also include a communication interface 168 for communicating with other components of the system, for example. The communication interface 168 may include any suitable components for interfacing with one or more networks, including, for example, transmitters, receivers, ports, controllers, antennas, or other suitable components.

[0117] Generation of a single observation image

[0118] The manner in which a single observation image can be generated by one or more processors using images captured by the imaging device will now be described in detail. Capturing the transient thermal response into a single observation image allows for faster and more accurate inspection of the component. The 3D data (multiple captured images or movies) is intelligently processed into a 2D image indicative of the transient thermal response of the component without depicting the heating element traversing.

[0119] Figure 14 A flowchart of an example method (400) for generating a single observation image is provided. For example, the method (400) can be used to generate Figure 9 a single image 250. Referring to Figure 12 , one or more processors 164 of the computing system 160 may execute the single image generator component 165 of the instructions 166A to generate the single image 250. For purposes of illustration and discussion, Figure 14 the actions are depicted in a particular order. Those of ordinary skill in the art using the disclosure provided herein will understand that the various actions of any method disclosed herein can be modified in various ways without departing from the scope of the present disclosure. Reference will be made to the various features of the coating inspection system 100 and the component 200 described herein and shown in the figures.

[0120] At (402), the method (400) includes receiving, by one or more processors, a plurality of images captured by the imaging device. Each of the plurality of images captures a component having a barrier coating while a heating element traverses and applies heat to the component in a transverse direction. For example, one or more processors 164 of the computing system 160 may receive a plurality of images captured by the imaging camera 152. The component may be Figure 1 the component 200 depicted inFigure 1 The imaging camera 152 can capture an image of the thermal response of the component 200 when the heating element 112 traverses along its traverse path and applies heat to the component 200 (e.g., as Figures 4 - 7 shown). That is, in response to the heating element 112 sweeping across the component 200 and imparting heat to the component 200, each image can capture the instantaneous temperature distribution of the component 200. Since cracks and other defects are surface discontinuities, they create obstacles for the flow of eddy currents, and thus, hot spots form as temporal and spatial events in the temperature distribution of the images captured by the imaging device. Therefore, individual images can each capture the local transient thermal response of the component. Each image can have the same number of pixels.

[0121] At (404), the method (400) includes generating a plurality of masked images using the plurality of captured images. For example, one or more processors 164 of the computing system 160 can use the captured images received at (402) to generate the masked images. In some embodiments, the masked images are generated by positioning a masking window adjacent to and in front of the heating element along the traverse direction for each of the plurality of images and applying thermal data to the pixels within the masking window of each of the plurality of images.

[0122] As an example, Figures 15 - 18 depicts a plurality of images 260 of the component 200 captured by the imaging device when the heating element 112 traverses across and applies heat to the component 200 along the traverse direction T1 relative to the component 200. In this example, the traverse direction T1 is the direction along the vertical direction V. However, as noted, in other embodiments, the traverse direction T1 can extend along a different direction. Additionally, it should be understood that the imaging device can capture many more images than Figures 15 - 18 shown in, including images captured before, between, or after the depicted captured images 260. The captured images 260 or frames can jointly capture the progress of the heating element 112 traversing the entire length (e.g., vertical length) of the component 200.

[0123] As Figure 15 、 16 each of the images 260 of 17 and 18 shows, one or more processors of the computing system 160 position a masking window 270 adjacent to and in front of the heating element 112 along the traverse direction T1. Thus, as shown, the masking window 270 moves frame-by-frame or image-by-image together with the heating element 112. The masking window 270 is depicted as a rectangle in Figures 15 - 18 but other shapes are possible.

[0124] In the system 100( Figure 1) One observation found during the experiment is that when the heating element 112 traverses relative to the component 200, thermal transients or anomalies start to appear in front of the heating element 112. In particular, the thermal transients appear significantly relative to their background (i.e., non-defective area) just in front of the heating element 112. Thus, in some embodiments, the masking window 270 is placed adjacent to and in front of the heating element 112 in each captured image 260. Thus, in this example, in Figures 15 - 18 each captured image 260 of, the masking window 270 is placed adjacent to and in front of the heating element 112 (just below the heating element 112 along the vertical direction V).

[0125] As Figure 15 best shown, each masking window 270 has a first length Ll (e.g., a length extending along the traverse direction Tl) and a second length L2 (e.g., a length extending perpendicular to the traverse direction Tl). For this embodiment, the second length L2 of the masking window 270 spans the width of the captured image 260. Each masking window may have a second length L2 that spans the width of the image on which the masking window lies. In some embodiments, the second length L2 of the masking window 270 spans the width of the component 200. The first length L1 of the masking window 270 can be selected based on the selected thermal output and the traverse speed of the heating element 112. In some embodiments, the first length L1 of the masking window 270 is selected such that the masking window 270 captures the thermal response of the component 200 generated by the heat radiated by the heating element 112 within its perimeter, but otherwise kept as short as possible to minimize computer processing time. In some embodiments, the first length L1 of the masking window 270 is less than one quarter of the component length LC1 of the component 200. The component length LC1 extends along the traverse direction T1. In some embodiments, the first length L1 of the masking window 270 is less than one eighth of the component length LC1 of the component 200.

[0126] With the masking window 270 positioned adjacent to and in front of the heating element 112 in each captured image 260, one or more processors 164 of the computing system 160 apply the thermal data to the pixels within the masking window 270 of each image 260. Notably, the masking window 270 is used to mask the pixels outside its perimeter. Thus, for each image 260, the pixels outside the masking window 270 are ignored. In some embodiments, the imaging device is an infrared imaging device and the thermal data is three-dimensional (3D) infrared sensor data. The thermal data may indicate the instantaneous temperature distribution of the component 200. In some embodiments, applying the thermal data to the pixels located within the corresponding masking window in each of a plurality of images includes assigning a value (e.g., a temperature value) to each pixel located within the corresponding masking window in the image.

[0127] As an example, Figure 19 a schematic diagram of thermal data for pixels of a masking window applied to each image is provided. As shown, thermal data 280A is applied to pixel P located within masking window 270A on first captured image 260A, thermal data 280B is applied to pixel P located within masking window 270B on second captured image 260B, thermal data 280C is applied to pixel P located within masking window 270C on third captured image 260C, and so on for N captured images, where N is an integer. Each pixel within a particular masking window can receive thermal data (e.g., receive a temperature value). As depicted, thermal data 280A, 280B, 280, and 280N are only applied to pixel P within respective masking windows 270A, 270B, 270C, and 270N of captured images 260A, 260B, 260C, and 260N. Pixels outside the masking window are ignored. Among other benefits, masking pixels outside the masking window can reduce the processing time and computing resources required to apply thermal data to the 2D captured image.

[0128] Figure 20 A schematic diagram of a plurality of generated masking images 290 is provided. Each generated masking image 290 represents pixels to which thermal data has been applied of its associated masking window. For example, first masking image 290A represents pixel P to which thermal data 280A has been applied of its associated first masking window 270A, second masking image 290B represents pixel P to which thermal data 280B has been applied of its associated second masking window 270B, third masking image 290C represents pixel P to which thermal data 280C has been applied of its associated third masking window 270C, and so on up to the Nth masking image.

[0129] As described above, when the heating element traverses relative to the component, a thermal transient or an anomaly onset is found to occur in front of the heating element. Capturing and considering pixels in front of the heating element can provide valuable insights to determine the maximum temperature value and / or heating rate associated with the pixels. However, as described above, the minimum temperature value and / or cooling rate associated with the pixels can also be considered. It can be understood that after the heating element traverses a particular portion of the component, the component begins to cool. To capture the minimum temperature value and / or cooling rate associated with the pixels, in some embodiments, the masking window can be positioned behind the heating element along the traversing direction. It should also be understood that the maximum temperature value can be captured within a masking window positioned behind the heating element. Additionally, insights into the heating rate associated with the pixels can also be captured within a masking window positioned behind the heating element.

[0130] As an example, as Figure 21 shown, in each captured image ( Figure 21In the only captured image shown (image 260), the masking window 270 is positioned adjacent to and behind the heating element 112 along the transverse direction T1. Thus, Figure 21 the masking window 270 is positioned to capture the transient thermal response of the component 200 as the component 200 cools. In some embodiments, the masking window 270 positioned behind the heating element 112 along the transverse direction T1 does not need to be positioned adjacent to the heating element 112; instead, there may be a space, for example, along the transverse direction T1 between the heating element 112 and the masking window 270.

[0131] In other embodiments, the masking window includes two sections, including a front section and a rear section. In such embodiments, in each captured image, the front section of the masking window is positioned adjacent to and in front of the heating element along the transverse direction, and the rear section of the masking window in each captured image is positioned adjacent to and behind the heating element along the transverse direction. In such embodiments, the front section and the rear section may be discontinuous sections.

[0132] As another example, as Figure 22 shown, the masking window 270 includes two sections, including a front section 272 and a rear section 274. In such embodiments, in each captured image ( Figure 22 only one captured image 260 is shown), the front section 272 of the masking window 270 is positioned adjacent to and in front of the heating element 112 along the transverse direction T1, and the rear section 274 of the masking window 270 in each captured image is positioned adjacent to and behind the heating element 112 along the transverse direction T1. The front section and the rear section 272, 274 may be discontinuous sections, as Figure 21 shown. Additionally, in such embodiments, the rear section 274 may have a length L1-B (e.g., a length extending along the transverse direction T1), and the length L1-B is at least twice the length L1-F (e.g., a length extending along the transverse direction T1) of the front section 272 of the masking window 270.

[0133] In some embodiments, the front section 272 positioned in front of the heating element 112 along the transverse direction T1 does not need to be positioned adjacent to the heating element 112; instead, there may be a space, for example, along the transverse direction T1 between the heating element 112 and the front section 272. Additionally or alternatively, in some embodiments, the rear section 274 positioned behind the heating element 112 along the transverse direction T1 does not need to be positioned adjacent to the heating element 112; instead, there may be a space, for example, along the transverse direction T1 between the heating element 112 and the rear section 274.

[0134] At (406), method (400) includes determining a minimum value and / or a maximum value associated with each pixel on a plurality of masked images based at least in part on applied thermal data. That is, considering all thermal data values for a particular pixel, a minimum value and / or a maximum value is determined for that particular pixel. In some embodiments, the minimum value and / or the maximum value is a minimum temperature value and / or a maximum temperature value. In some embodiments, determining a minimum value and / or a maximum value associated with each pixel on a plurality of masked images at (406) includes determining, for each pixel in the plurality of masked images, each masked image among the plurality of masked images in which a given pixel of the plurality of masked images is represented, and comparing values associated with the given pixel from each masked image in which the given pixel is represented. To determine the minimum value, the smallest value associated with the given pixel is selected as the minimum value associated with the given pixel. To determine the maximum value, the largest value associated with the given pixel is selected as the maximum value associated with the given pixel.

[0135] As an example, Figure 23 Depicted are a number of masked images 290, including a first masked image 290D, a second masked image 290E, a third masked image 290F, and a fourth masked image 290G. The masked images 290D, 290E, 290F, and 290G are created using consecutive images captured by an imaging device. Each masked image 290 includes a plurality of pixels P. Some or all of the pixels P may be represented in the plurality of masked images 290. For example, as shown, pixel P10 is represented in the plurality of masked images 290.

[0136] To determine the maximum value associated with pixel P10 on multiple masked images 290, each masked image in which pixel P10 appears is determined. In this example, pixel P10 is found within the perimeters of the first masked image 290D, the second masked image 290E, and the third masked image 290F, but not within the perimeter of the fourth masked image 290G. Thus, only the first, second, and third masked images 290D, 290E, 290F are considered to determine the maximum value of pixel P10. In the first masked image 290D, pixel P10 has a value T1 (e.g., a temperature value). In the second masked image 290E, pixel P10 has a value T2. In the third masked image 290F, pixel P10 has a value T3. In this example, for pixel P10, T3 > T2 > T1. Thus, for pixel P10, the maximum value is T3. It should be understood that the maximum value for each pixel on the multiple masked images 290 can be determined in the same manner as described for pixel P10. For example, the maximum value of pixel P11 can be determined in the same manner. In this example, for pixel P11, T2 > T3 > T1. Thus, for pixel P11, the maximum value is determined to be T2. The minimum value of a pixel can be determined in a similar manner as described, except that the minimum value is used instead of the maximum value.

[0137] At (408), method (400) includes generating a single observation image using multiple masked image generating components and causing the determined minimum and / or maximum values associated with each pixel in the multiple masked images to be represented in the single observation image. For example, one or more processors of computing system 160 can generate a single observation image. In some embodiments, one or more processors of computing system 160 can generate a single observation image such that the determined maximum value associated with each pixel in the multiple masked images is represented in the single observation image. In other embodiments, one or more processors of computing system 160 can generate a single observation image such that the determined minimum value associated with each pixel in the multiple masked images is represented in the single observation image. In yet another embodiment, one or more processors of computing system 160 can generate two single observation images, including a single observation image representing the determined maximum value and a single observation image representing the determined minimum value.

[0138] As an example, Figure 24 A generated single observation image 250 with multiple pixels P is depicted. Notably, the pixels P of the single observation image 250 represent or depict the same corresponding portions of component 200 as they do in the masked images 290 and the captured image 260. Thus, throughout the single observation image generation process, a particular pixel always represents the same portion of component 200. For example, pixel P12 can represent in the captured image, in the generated masked image, and in, asFigure 24 A portion of the leading edge of component 200 in the final single observation image 250 shown.

[0139] Each pixel P of the single observation image 250 representing a portion of component 200 shows the respective portion of component 200 and the transient thermal response of component 200. The transient thermal response of component 200 is represented as the determined maximum value of the corresponding pixel in the single observation image 250. For example, the determined maximum value of pixel P10 of the single observation image 250 is determined to be T3 (e.g., which is extracted or determined from Figure 23 the third masked image 290F in). Thus, in the single observation image 250, the thermal response of component 200 at pixel P10 is depicted as T3. The determined maximum value of pixel P11 of the single observation image 250 is determined to be T2 (e.g., which is extracted or determined from Figure 23 the third masked image 290F in). Thus, in the single observation image 250, the thermal response of component 200 at pixel P11 is depicted or represented as T2. Other pixels P of the single observation image 250 can similarly represent their respective determined maximum values.

[0140] It is noted that the heating element 112 ( Figure 19 ) is not present or is almost removed in the generated single observation image 250. Since pixels are selected from the pixels of the masked image 290 to finally display their maximum values, the heating element 112 is not present in the single observation image 250. Thus, although the imaging camera 152 ( Figure 1 ) captures the heating element 112 in the multiple captured images 260 ( Figures 15 - 18 ), the single observation image 250 does not include the footprint of the heating element 112. This can provide a clearer image and can facilitate, for example, the detection of defects of component 200 and the analysis of the thermal response at (314), (316), and (318) of the method (300) described herein.

[0141] The techniques discussed herein refer to computer-based systems, actions taken by computer-based systems, information sent to computer-based systems, and information from computer-based systems. It should be understood that the inherent flexibility of computer-based systems allows for a variety of possible configurations, combinations, and divisions of tasks and functions among and within components. For example, the processes discussed herein can be implemented using a single computing device or multiple computing devices working in combination. Databases, memories, instructions, and applications can be implemented on a single system or distributed across multiple systems. Distributed components can operate sequentially or in parallel.

[0142] While specific features of various embodiments may be shown in some figures and not in others, this is merely for convenience. In accordance with the principles of this disclosure, any feature of any figure may be referenced and / or claimed in combination with any feature of any other figure.

[0143] This written description uses examples to disclose the invention, including the best mode, and also enables any person skilled in the art to practice the invention, including making and using any device or system and performing any incorporated method. The patentable scope of the invention is defined by the claims and may include other examples that occur to those skilled in the art. If these other examples include structural elements that are not different from the literal language of the claims, or if they include equivalent structural elements that are not substantially different from the literal language of the claims, then these other examples are intended to fall within the scope of the claims.

[0144] A further aspect of the invention is provided by the subject matter of the following clauses:

[0145] 1. A method of generating a single observation image, the method comprising: receiving, by one or more processors, a plurality of images captured by an imaging device, each of the plurality of images capturing the component having a coating as a heating element traverses and applies heat to the component in a traverse direction relative to the component; generating, by the one or more processors, a plurality of masked images by, for each of the plurality of images, positioning a masking window relative to the heating element by the one or more processors; and applying, by the one or more processors, thermal data to pixels within the masking window of each of the plurality of images; determining, at least in part based on the applied thermal data, a minimum value or a maximum value associated with each pixel on the plurality of masked images; and generating the single observation image of the component using the plurality of masked images such that the determined minimum value or maximum value associated with each pixel of the plurality of masked images is represented in the single observation image.

[0146] 2. The method according to any of the preceding clauses, wherein the thermal data is applied only to the pixels within the masking window of each of the plurality of masked images.

[0147] 3. The method according to any of the preceding clauses, wherein the imaging device is an infrared imaging device and the thermal data is three-dimensional infrared sensor data.

[0148] 4. The method according to any of the preceding clauses, wherein the minimum value or the maximum value is a minimum temperature value or a maximum temperature value.

[0149] 5. The method according to any of the preceding clauses, wherein the heating element is not present in the generated single observation image.

[0150] 6. A method according to any of the preceding clauses, wherein applying the thermal data to the pixels within the masking window of each of the plurality of images by the one or more processors comprises: assigning a value to each of the pixels within the masking window of each of the plurality of images.

[0151] 7. A method according to any of the preceding clauses, wherein determining the minimum or maximum value associated with each pixel on the plurality of masked images based at least in part on the applied thermal data comprises: for each pixel on the plurality of masked images, determining each of the plurality of masked images in which the given pixel representing the pixel on the plurality of masked images is represented; comparing the values assigned to the given pixel from each of the masked images in which the given pixel is represented, wherein when the value assigned to the given pixel is the minimum value, the smallest of the values associated with the given pixel is selected as the minimum value associated with the given pixel, and wherein when the value assigned to the given pixel is the maximum value, the largest of the values associated with the given pixel is selected as the maximum value associated with the given pixel.

[0152] 8. A method according to any of the preceding clauses, wherein the component has a component length extending along the transverse direction, and the masking window of each of the plurality of images has a first length extending along the transverse direction, and wherein the first length of the masking window of each of the plurality of images is less than one quarter of the component length.

[0153] 9. A method according to any of the preceding clauses, wherein the component has a metal structure and the coating is a non-conductive coating.

[0154] 10. A method according to any of the preceding clauses, wherein positioning the masking window relative to the heating element by the one or more processors in each of the plurality of images comprises positioning the masking window in front of the heating element along the transverse direction.

[0155] 11. A method according to any of the preceding clauses, wherein positioning the masking window relative to the heating element by the one or more processors in each of the plurality of images comprises positioning the masking window behind the heating element along the transverse direction.

[0156] 12. The method according to any of the preceding clauses, wherein positioning the masking window relative to the heating element in each of the plurality of images by the one or more processors includes positioning a front section of the masking window in front of the heating element along the transverse direction and positioning a rear section of the masking window behind the heating element along the transverse direction, the front section and the rear section being discontinuous.

[0157] 13. A system comprising: a heating element; an imaging device; a computing system having one or more processors and one or more memory devices, the one or more processors being configured to: receive a plurality of images captured by the imaging device, each of the plurality of images capturing the component having a coating when the heating element traverses and applies heat to the component along a transverse direction; generate a plurality of masked images by, for each of the plurality of images, positioning a masking window relative to the heating element; and applying thermal data to pixels within the masking window of each of the plurality of images; determine a minimum or maximum value associated with each pixel on the plurality of masked images based at least in part on the applied thermal data; and generate a single observation image of the component using the plurality of masked images and cause the determined minimum or maximum value associated with each of the pixels in the plurality of masked images to be represented in the single observation image.

[0158] 14. The system according to any of the preceding clauses, wherein the heating element is not present in the generated single observation image.

[0159] 15. The system according to any of the preceding clauses, wherein the imaging device is at least one of a mid-wavelength imaging camera and a long-wavelength imaging camera, wherein the mid-wavelength imaging camera captures wavelengths in the range of approximately three to six micrometers and the long-wavelength imaging camera captures wavelengths in the range of approximately six to fourteen micrometers.

[0160] 16. The system according to any of the preceding clauses, wherein the component has a component length extending along the transverse direction and the masking window of each of the plurality of images has a first length extending along the transverse direction, and wherein the first length of the masking window of each of the plurality of images is less than one-eighth of the component length.

[0161] 17. The system according to any of the preceding clauses, wherein the masking window of each of the plurality of images has a second length spanning the width of the image on which the masking window is positioned.

[0162] 18. A non-transitory computer-readable medium comprising computer-executable instructions that, when executed by one or more processors of a coating inspection system, cause the one or more processors to: receive a plurality of images captured by an imaging device, each of the plurality of images capturing the component having a coating as the heating element of the coating inspection system traverses and applies heat to the component in a traverse direction; generate a plurality of masked images by, for each of the plurality of images, positioning a masking window relative to the heating element; and applying thermal data to pixels within the masking window of each of the plurality of images; determine a minimum or maximum value associated with each pixel on the plurality of masked images, at least in part based on the applied thermal data; and generate a single observation image of the component using the plurality of masked images such that the determined minimum or maximum value associated with each pixel of the plurality of masked images is represented in the single observation image.

[0163] 19. The computer-readable medium according to any of the preceding clauses, wherein in determining the minimum or maximum value associated with each pixel on the plurality of masked images, at least in part based on the applied thermal data, when the computer-executable instructions are executed by the one or more processors of the coating inspection system, further cause the one or more processors to: for each pixel of the plurality of masked images, determine each of the plurality of masked images in which a given pixel representing the pixel of the plurality of masked images is represented; compare the values associated with the given pixel from each of the masked images in which the given pixel is represented, wherein when the value associated with the given pixel is a minimum value, the smallest value associated with the given pixel is selected as the minimum value associated with the given pixel, and wherein when the value associated with the given pixel is a maximum value, the largest value associated with the given pixel is selected as the maximum value associated with the given pixel.

[0164] 20. The computer-readable medium according to any of the preceding clauses, wherein the component has a component length extending in the traverse direction, and the masking window of each of the plurality of images has a first length extending in the traverse direction, and wherein the first length of the masking window of each of the plurality of images is less than one quarter of the component length.

Claims

1. A method for generating a single observation image, characterized in that, The method includes: Receiving, by one or more processors, a plurality of images captured by an imaging device, wherein the plurality of images of the component are captured by the imaging device while a heating element traverses and applies heat to the component in a traverse direction relative to the component, the component having a coating; Generating, by the one or more processors, a plurality of masked images by, for each image of the plurality of images, positioning a masking window relative to the heating element by the one or more processors and applying thermal data to pixels within the masking window of each image of the plurality of images; Determining, at least in part based on the applied thermal data, a minimum value or a maximum value associated with each pixel on the plurality of masked images; and Generating, using the plurality of masked images, the single observation image of the component such that the determined minimum value or maximum value associated with each pixel in the plurality of masked images is represented in the single observation image.

2. The method according to claim 1, characterized in that, Wherein the thermal data is applied only to the pixels within the masking window of each of the plurality of masked images.

3. The method according to claim 1, characterized in that Wherein the imaging device is an infrared imaging device and the thermal data is three-dimensional infrared sensor data.

4. The method according to claim 1, wherein Wherein the minimum value or the maximum value is a minimum temperature value or a maximum temperature value.

5. The method according to claim 1, wherein Wherein the heating element is not present in the generated single observation image.

6. The method according to claim 1, wherein Wherein applying the thermal data to the pixels within the masking window of each image of the plurality of images by the one or more processors includes: Assigning a value to each pixel within the masking window of each image of the plurality of images.

7. The method according to claim 6, wherein Wherein determining the minimum value or the maximum value associated with each pixel on the plurality of masked images at least in part based on the applied thermal data includes: For each pixel in the plurality of masked images, determining each masked image of the plurality of masked images in which the pixel of the plurality of masked images is represented; Comparing the values assigned to the given pixel from each of the masked images in which the given pixel is represented, wherein when the value assigned to the given pixel is a minimum value, the smallest of the values associated with the given pixel is selected as the minimum value associated with the given pixel, and wherein when the value assigned to the given pixel is a maximum value, the largest of the values associated with the given pixel is selected as the maximum value associated with the given pixel.

8. The method according to claim 1, wherein Wherein the component has a component length extending in the traverse direction and the masking window of each image of the plurality of images has a first length extending in the traverse direction, and wherein the first length of the masking window of each image of the plurality of images is less than one quarter of the component length.

9. The method according to claim 1, wherein Wherein the component has a metal structure and the coating is a non-conductive coating.

10. The method according to claim 1, characterized in that Wherein positioning the masking window relative to the heating element by the one or more processors in each of the plurality of images includes positioning the masking window in front of the heating element along the transverse direction.

11. The method according to claim 1, characterized in that Wherein positioning the masking window relative to the heating element by the one or more processors in each of the plurality of images includes positioning the masking window behind the heating element along the transverse direction.

12. The method according to claim 1, wherein Wherein positioning the masking window relative to the heating element by the one or more processors in each of the plurality of images includes positioning a front section of the masking window in front of the heating element along the transverse direction and positioning a rear section of the masking window behind the heating element along the transverse direction, the front section and the rear section being discontinuous.

13. A system, characterized in that, Comprising: A heating element; An imaging device; A computing system having one or more processors and one or more memory devices, the one or more processors being configured to: Receive a plurality of images captured by the imaging device, wherein the plurality of images of the component are captured by the imaging device when the heating element traverses and applies heat to the component along a transverse direction, the component having a coating; Generate a plurality of masked images by, for each of the plurality of images, positioning a masking window relative to the heating element and applying thermal data to pixels within the masking window of each of the plurality of images; Determine a minimum value or a maximum value associated with each pixel on the plurality of masked images, at least in part based on the applied thermal data; and Generate a single observation image of the component using the plurality of masked images such that the determined minimum value or maximum value associated with each pixel in the plurality of masked images is represented in the single observation image.

14. The system according to claim 13, characterized in that, Wherein the heating element is not present in the generated single observation image.

15. The system according to claim 13, wherein Wherein the imaging device is at least one of a mid-wavelength imaging camera and a long-wavelength imaging camera, wherein the mid-wavelength imaging camera captures wavelengths in the range of three to six micrometers and the long-wavelength imaging camera captures wavelengths in the range of six to fourteen micrometers.

16. The system according to claim 13, wherein Wherein the component has a component length extending along the transverse direction, and the masking window of each of the plurality of images has a first length extending along the transverse direction, and wherein the first length of the masking window of each of the plurality of images is less than one-eighth of the component length.

17. The system according to claim 16, wherein Wherein the masking window of each of the plurality of images has a second length spanning the width of the image on which the masking window is positioned.

18. A non-transitory computer-readable medium, characterized in that, The non-transitory computer-readable medium includes computer-executable instructions that, when executed by one or more processors of a coating inspection system, cause the one or more processors to: Receiving a plurality of images captured by an imaging device, wherein the plurality of images of the component having a coating are captured by the imaging device while a heating element of the coating inspection system traverses and applies heat to the component in a traverse direction relative to the component; Generating a plurality of masked images by, for each image of the plurality of images, positioning a masking window relative to the heating element and applying thermal data to pixels within the masking window of each image of the plurality of images; Determining a minimum value or a maximum value associated with each pixel on the plurality of masked images, at least in part based on the applied thermal data; and Generating a single observation image of the component using the plurality of masked images such that the determined minimum value or maximum value associated with each pixel in the plurality of masked images is represented in the single observation image.

19. The computer-readable medium according to claim 18, wherein, Wherein in determining the minimum value or the maximum value associated with each pixel on the plurality of masked images, at least in part based on the applied thermal data, when the computer-executable instructions are executed by the one or more processors of the coating inspection system, further causing the one or more processors to: For each pixel in the plurality of masked images, determine each of the plurality of masked images in which a given pixel representing the pixel in the plurality of masked images is represented; Compare the values associated with the given pixel from each of the masked images in which the given pixel is represented, wherein when the value associated with the given pixel is a minimum value, the smallest of the values associated with the given pixel is selected as the minimum value associated with the given pixel, and wherein when the value associated with the given pixel is a maximum value, the largest of the values associated with the given pixel is selected as the maximum value associated with the given pixel.

20. The computer-readable medium according to claim 18, wherein Wherein the component has a component length extending in the traverse direction and the masking window of each image of the plurality of images has a first length extending in the traverse direction, and wherein the first length of the masking window of each image of the plurality of images is less than a quarter of the component length.

Images