Automated TFM grid resolution setting tool

Abstract

Examples of the present subject matter provide techniques for computing amplitude fidelity (AF) for various grid resolutions using a single TFM image that specifies a defect. Thus, the grid resolution can be set using a computational process without performing a blind iterative process such that it results in a desired AF. Furthermore, examples of the present subject matter can measure AF in more than one axis, thereby improving accuracy.

Description

[0001] Cross-references to related applications

[0002] This application claims the benefit of priority to U.S. Patent Application Serial No. 17 / 066,798, filed on October 9, 2020, the contents of which are incorporated herein by reference in their entirety. Technical Field

[0003] This disclosure generally relates to non-destructive testing using the total-focusing method (TFM). Background Technology

[0004] Ultrasonic inspection can be a useful inspection technique for a wide variety of structures. Inhomogeneities on or within the structure under test can generate scattered or reflected acoustic signals in response to emitted acoustic pulses. Such acoustic "echoes" can be received and processed. Processing can include reconstructing images corresponding to areas of the structure under test for review by inspectors or for archiving. Features that can be detected and thus imaged within the structure include interfaces between materials with different acoustic propagation characteristics (e.g., voids, cracks, or other defects) and structures (e.g., welds, joints, cladding layers, or surfaces).

[0005] Processing the received acoustic echo signals to form an image can involve various techniques. One approach uses a technique called "Full Matrix Capture" (TFM), which can involve a full matrix capture (FMC) acquisition scheme where focusing can be achieved across a wide spatial area on or within the structure under test. TFM is integrated into various inspection specifications and standards, such as ASME Section 5 (2019 ASME Boiler and Pressure Vessel Code, Section 5: Nondestructive Testing) and ISO 23865 (Nondestructive Testing – Ultrasonic Testing – General Application of Full Matrix Capture / Full Matrix Capture / TFM Techniques). These specifications may require the operator to ensure that the TFM mesh resolution allows for a certain level (e.g., 2 dB or less) of amplitude fidelity (AF). AF corresponds to the maximum amplitude variation of a given defect caused by the resolution (e.g., the distance between two grid points in the TFM mesh). Generally, the coarser the mesh resolution, the higher the AF value it will produce.

[0006] Therefore, technicians can use an iterative trial-and-error process to set the mesh resolution to produce a specific AF value. That is, the technician can set the mesh resolution to a first value, obtain a TFM image of the specified defect, measure the amplitude change by moving the TFM mesh in one direction (e.g., horizontal), and calculate the AF value. Then, if the calculated AF value is not at the desired value, the technician will adjust the mesh value accordingly and repeat the process until it produces the desired AF value. Attached Figure Description

[0007] The accompanying figures illustrate only exemplary implementations of this disclosure and should not be construed as limiting the scope of this disclosure.

[0008] Figure 1 An example inspection system based on this topic is shown.

[0009] Figure 2 This is a flowchart illustrating the process of calculating grid resolution based on examples from this topic.

[0010] Figures 3A to 3F A graphical representation of some steps in the process of calculating grid resolution, based on an example of this topic, is shown.

[0011] Figures 4A to 4C Another example is shown, graphically representing certain steps of the process for calculating grid resolution according to examples in this topic.

[0012] Figures 5A to 5C Another example is shown, graphically representing certain steps of the process for calculating grid resolution according to examples in this topic.

[0013] Figures 6A to 6D The various parts of the AF verification process, as shown in the example of this topic, are illustrated.

[0014] Figure 7 A block diagram is shown illustrating an example of a machine that can perform any or more of the techniques (e.g., methods) discussed herein. Detailed Implementation

[0015] Furthermore, the inventors have recognized a need in the art for inspection systems that overcome the challenges discussed above. Examples of this subject matter provide techniques for calculating AF at various mesh resolutions using a single TFM image of a specified defect. Therefore, the mesh resolution can be set to produce the desired AF using computational processing without performing the blind iterative processing described above. Moreover, examples of this subject matter can measure AF on more than one axis, thereby improving accuracy.

[0016] This paper describes a method comprising: constructing a TFM image of a representation of defects in an object at a first grid resolution; determining the centroid of the representation of defects based on the TFM image; identifying the major and minor axes of the representation of defects; determining multiple pixel or voxel values ​​along the major and minor axes based on the TFM image; and determining a second grid resolution corresponding to a specified amplitude fidelity based on the multiple pixel or voxel values ​​along the major and minor axes.

[0017] This document also describes a machine storage medium including instructions that, when executed by a machine, cause the machine to perform operations including: constructing a TFM image representing a defect in an object at a first grid resolution; determining the centroid of the defect representation based on the TFM image; identifying the major and minor axes of the defect representation; determining a plurality of pixel or voxel values ​​along the major and minor axes based on the TFM image; and determining a second grid resolution corresponding to a specified amplitude fidelity based on the plurality of pixel or voxel values ​​along the major and minor axes.

[0018] This document also describes a system having one or more processors of a machine. The system further includes a memory storing instructions that, when executed by the one or more processors, cause the machine to perform operations including: constructing a TFM image representing a defect in an object at a first grid resolution; determining the centroid of the defect representation based on the TFM image; identifying the major and minor axes of the defect representation; determining a plurality of pixel or voxel values ​​along the major and minor axes based on the TFM image; and determining a second grid resolution corresponding to a specified amplitude fidelity based on the plurality of pixel or voxel values ​​along the major and minor axes.

[0019] Figure 1 An example of an acoustic inspection system 100, including, for example, techniques that can be used to perform one or more of the techniques shown and described elsewhere herein, is generally illustrated. The inspection system 100 may include a test instrument 140, such as a handheld or portable component. The test instrument 140 may be electrically coupled to a probe assembly, for example, using a multi-conductor interconnect 130. The probe assembly 150 may include one or more electroacoustic transducers, such as a transducer array 152 including corresponding transducers 154A to 154N. The transducer array may follow a linear or curved profile, or may include an array of elements extending along two axes, for example, to provide a matrix of transducer elements. The space occupied by the elements does not need to be square or arranged along a straight axis. The element size and spacing may vary depending on the inspection application.

[0020] Modular probe assembly 150 can be configured, for example, to enable test instrument 140 to be used with different probe assemblies 150. Typically, transducer array 152 includes piezoelectric transducers that can be acoustically coupled to a target 158 ​​(e.g., the test object) via coupling medium 156. The coupling medium can include a fluid or gel or solid film (e.g., an elastomer or other polymeric material) or a combination of fluid, gel, or solid structures. For example, the acoustic transducer assembly can include a transducer array coupled to a wedge-shaped structure comprising a rigid thermosetting polymer (e.g., available from C-Lec Plastics) with known acoustic propagation characteristics. Furthermore, during the test, water can be injected as a coupling medium 156 between the wedge and the structure under test.

[0021] Test instrument 140 may include digital and analog circuitry, such as front-end circuitry 122 comprising one or more transmit signal chains, receive signal chains, or switching circuitry systems (e.g., transmit / receive switching circuitry systems). The transmit signal chains may include amplifier and filter circuitry systems, for example, to provide transmit pulses delivered via interconnect 130 to probe assembly 150 for acoustic transmission to target 158, for example, to image or otherwise detect defects 160 on or within the structure of target 158 ​​by receiving scattered or reflected acoustic energy induced in response to acoustic transmission.

[0022] Although Figure 1 A single probe assembly 150 and a single transducer array 152 are shown, but other configurations may also be used, such as multiple probe assemblies connected to a single test instrument 140, or multiple transducer arrays 152 used in conjunction with one or more probe assemblies 150 for cascade inspection. Similarly, test protocols can be executed using coordination between multiple test instruments 140, for example, in response to an overall test plan established from a master test instrument 140 or by another remote system (e.g., computing facility 108 or general-purpose computing devices such as laptop computer 132, tablet computer, smartphone, desktop computer, etc.). As an illustrative example, test plans can be established according to published standards or regulatory requirements, and can be executed at initial manufacturing or on a recurring basis for continuous monitoring.

[0023] The receiving signal chain of the front-end circuitry 122 may include one or more filter or amplifier circuits and analog-to-digital conversion facilities, for example, to digitize the echo signal received using probe assembly 150. Digitization may be performed coherently, for example, to provide multiple digitized data channels aligned or referenced to each other in time or phase. The front-end circuitry 122 may be coupled to and controlled by one or more processor circuits, such as processor circuitry 102 included as part of test instrumentation 140. The processor circuitry may be coupled to memory circuitry, for example, to execute instructions that cause test instrumentation 140 to perform one or more of the acoustic emission, acoustic acquisition, processing, or storage of data related to acoustic inspection, or otherwise perform the techniques shown and described herein. Test instrumentation 140 may be communicatively coupled to other parts of system 100, for example, using wired or wireless communication interface 120.

[0024] For example, the implementation of one or more techniques as shown and described herein can be carried out on the on-board test instrument 140 or using other processing or storage facilities—such as computing facility 108 or general-purpose computing devices such as laptop computer 132, tablet computer, smartphone, desktop computer, etc. For example, processing tasks that would be undesirably slow or beyond the capabilities of the test instrument 140 if performed on the on-board test instrument 140 can be performed remotely (e.g., on a separate system) in response to a request from the test instrument 140. Similarly, the storage of imaging data or intermediate data, such as an A-scan matrix of time-series data, can be implemented using a remote facility communicatively coupled to the test instrument 140. The test instrument may include, for example, a display 110 for presenting configuration information or results and an input device 112 for receiving operator commands, configuration information, or responses to queries. The input device 112 may include, for example, one or more of a keyboard, trackball, function keys or soft keys, mouse interface, touchscreen, stylus, etc.

[0025] Next, we will refer to Figure 2 and Figures 3A to 3F Describes a technique for automatically setting the desired TFM grid resolution (points per wavelength) for the AF. Figure 2 This is a flowchart of the process of calculating the grid resolution 200 based on the example in this topic. Figures 3A to 3F A graphical representation of some steps of the process 200 according to an example of this topic is shown.

[0026] At position 202, a TFM image of a specified defect in an object (e.g., a calibration block) can be calculated or constructed. The TFM image can be constructed using a preset grid resolution. The preset grid resolution can be relatively higher than the estimated grid resolution of the desired AF. For example, a TFM image can be calculated using a grid resolution of 10 to 20 points per wavelength, while the estimated grid resolution of the desired AF (e.g., 2 dB) can be significantly smaller (e.g., 2 to 5 points per wavelength).

[0027] Figure 3A An example TFM image of a specified defect (e.g., a side-drilled hole (SDH)) is shown, calculated at a preset grid resolution of approximately 20 points per wavelength. As shown, the echo reflections representing the SDH are depicted by ellipses (e.g., larger ellipses).

[0028] At position 204, the centroid of the defect can be determined. The centroid can be automatically detected by measuring pixel or voxel values ​​(e.g., the amplitude level of pixel or voxel values) and identifying relevant points or regions. Points or regions can be identified by using a statistical average of the measured amplitude levels. In another example, points or regions can be identified by using the maximum amplitude. A standard weighted average of the locations can also be used to calculate the centroid. <r>, so that:

[0029]

[0030] Here, the summation index n iterates over all N pixels of the image, and the position r_n of each pixel is weighted by the amplitude |A_n|. The amplitude can be filtered before calculating the average. For example, a threshold can be applied to the amplitude so that only pixels with a |A_n| value higher than the threshold are retained before calculating the average position. Other spatial filters can also be designed and applied to the image before calculation to discard, for example, amplitude artifact features.

[0031] At position 206, based on the detected centroid, the major and minor axes of the ellipse representing the defect can be identified, and pixel or voxel values ​​(e.g., amplitude levels) can be measured at multiple points along the major and minor axes, respectively. The major axis may correspond to the waist axis, and the minor axis may correspond to the direction of sound propagation. Figure 3A The major and minor axes are marked in the image. Figure 3B The figure shows cross-sections of discrete measurements along both the major and minor axes. These measurements can then be normalized, as shown in the graph. Also as shown, measurements along the minor axis, corresponding to the direction of sound propagation, can vary more than measurements along the major axis (waist axis).

[0032] At point 208, for two cross-sections, interpolation techniques can be applied to fill in the points between discrete measurements and achieve better resolution. Interpolation techniques can include linear interpolation, quadratic function interpolation, quartic function interpolation, or other suitable interpolation techniques. Figure 3C The image shows the cross-section after interpolation.

[0033] At 210, the width of the curve can be calculated based on the selected normalized amplitude value "A" corresponding to the desired AF (e.g., "A" can be approximately equal to 0.8 for an AF of 2 dB). "A" can be selected by the operator or based on standards, specifications, etc. The width of the curve can correspond to the length of the major axis (or minor axis) (a or b) of the target ellipse size.

[0034] At position 212, based on the target ellipse size, the mesh resolution can be calculated to produce the desired AF. For example, as a constraint, the calculated mesh resolution may allow three mesh points along the target ellipse limit. Figure 3E The calculated mesh size is shown, along with three mesh points along the target ellipse shape. This demonstrates the maximum mesh size that satisfies the sought minimum AF value. Any translation of the ellipse along this mesh will satisfy the target AF value.

[0035] Steps 210 to 212 can be repeated for different AF values. Furthermore, the mesh resolutions for different AF values ​​can be compiled. For example, tables containing the results of steps 210 to 212 can be created for different AF values. These results can be inverted and interpolated to obtain the mesh resolution for any AF value. Figure 3F A graph showing different AF values ​​and their corresponding grid resolution values ​​is presented. In this example, for an AF of 2 dB, a grid resolution of 2.8561 points per wavelength is calculated. Other grid resolutions for different AF values ​​can also be calculated.

[0036] Therefore, instead of trial-and-error processing using multiple TFM images, the grid resolution corresponding to the desired AF can be calculated from a single TFM image. Furthermore, the technique described herein offers simpler operation, eliminating the need for technicians to move the probe or grid to measure individual AF values ​​at a given resolution. Additionally, the technique described herein illustrates the direction of sound propagation.

[0037] Figures 4A to 4C Another example is shown of the grid resolution used to calculate the desired AF value using the techniques described in this paper. Figure 4A The TFM image is shown, identifying the centroid of the specified defect as well as its major and minor axes. Figure 4B A cross section of interpolated data for amplitude measurements of the major and minor axes is shown. Figure 4C A graph showing the various AF values ​​and their corresponding grid resolution values ​​is presented. In this example, for an AF of 2 dB, a grid resolution of 2.0663 points per wavelength is calculated.

[0038] Figures 5A to 5C Another example is shown of the grid resolution used to calculate the desired AF value using the techniques described in this paper. Figure 5A The TFM image is shown, identifying the centroid of the specified defect as well as its major and minor axes. Figure 5B A cross section of interpolated data for amplitude measurements of the major and minor axes is shown. Figure 5C A graph showing the various AF values ​​and their corresponding grid resolution values ​​is presented. In this example, for an AF of 2 dB, a grid resolution of 2.0955 points per wavelength is calculated.

[0039] After selecting the TFM grid resolution to produce the desired AF, the actual AF of the TFM image generated using the selected grid resolution can be verified. Figures 6A to 6D The various parts of the AF verification process, as shown in the example from this topic, are illustrated. Figure 6A The image shows TFM images with two different grid resolutions. The larger grid resolution is the chosen grid resolution to produce the desired AF value. The smaller grid resolution could be, for example, one-tenth the size of the chosen grid resolution. The maximum amplitude can then be measured using one-hundredth of the grid points from a uniform grid set in the TFM image.

[0040] Next, as Figures 6B to 6D As shown, the selected grid can be moved in different directions. After each movement in a specified direction, the maximum amplitude can be measured using one-hundredth of a grid point. For example, as... Figure 6B As shown, the grid can be moved horizontally (x-axis), and the maximum amplitude can be measured. Figure 6C As shown, the grid can then be moved in the vertical direction (z-axis), and the maximum amplitude can be measured. Figure 6D As shown, the grid can then be moved diagonally, and the maximum amplitude can be measured. Amplitude fidelity can be calculated using the logarithm of the ratio between the highest and lowest maximum amplitude measurements performed after moving in different directions.

[0041] The techniques shown and described herein can be used as follows Figure 1 The inspection system 100 shown may be used as part of or in whole, or otherwise employed in accordance with the following: Figure 7 The machine in question is 700 to perform the operation. Figure 7 A block diagram is shown illustrating an example of a machine 700 that can perform any or more of the techniques (e.g., methods) discussed herein. In various examples, machine 700 may operate as a standalone device or may be connected (e.g., networked) to other machines. In a networked deployment, machine 700 may operate as a server machine, a client machine, or both in a server-client network environment. In the examples, machine 700 may act as a peer-to-peer (P2P) (or other distributed) network environment. Machine 700 may be a personal computer (PC), tablet device, set-top box (STB), personal digital assistant (PDA), mobile phone, web application, network router, switch, or bridge, or any machine capable of (sequentially or otherwise) executing instructions specifying actions to be taken by that machine. Furthermore, although only a single machine is shown, the term "machine" should also be considered to include any collection of machines that individually or collectively execute a set (or more) of instructions to perform any or more methods discussed herein, such as cloud computing, Software as a Service (SaaS), or other computer cluster configurations.

[0042] As described herein, examples may include logic or multiple components or mechanisms, or may be operated by logic or multiple components or mechanisms. A circuit system is a collection of circuits implemented in a tangible entity including hardware (e.g., simple circuits, gates, logic, etc.). The relationships between circuit system components can be flexible over time and due to potential hardware variability. A circuit system includes components that can perform a specified operation individually or in combination during operation. In the examples, the hardware of the circuit system may be immutably designed to perform a specified operation (e.g., hardwired). In the examples, the hardware including the circuit system may include variable-connected physical components (e.g., execution units, transistors, simple circuits, etc.), which include computer-readable media that are physically modified (e.g., magnetic ground, electrical ground, e.g., via a change in physical state or a transformation of another physical characteristic, etc.) to encode instructions for a specified operation. When connecting physical components, the potential electrical characteristics of the hardware composition may, for example, change from insulating to conductive or vice versa. Instructions enable embedded hardware (e.g., execution units or loading mechanisms) to hardware-wise create components of the circuit system via variable connections to perform a portion of a specified operation during operation. Therefore, when the device is in operation, the computer-readable medium is communicatively coupled to other components of the circuit system. In the example, any physical component can be used in more than one component of more than one circuit system. For example, in operation, an execution unit can be used at one point in time in a first circuit of a first circuit system and can be reused at different points in time by a second circuit in the first circuit system or a third circuit in the second circuit system.

[0043] Machine (e.g., computer system) 700 may include a hardware processor 702 (e.g., a central processing unit (CPU), a graphics processing unit (GPU), a hardware processor core, or any combination thereof), main memory 704, and static memory 706, some or all of which may communicate with each other via interconnect (e.g., bus) 708. Machine 700 may also include a display unit 720, an alphanumeric input device 722 (e.g., a keyboard), and a user interface (UI) navigation device 724 (e.g., a mouse). In the example, display unit 720, input device 722, and UI navigation device 724 may be a touchscreen display. Machine 700 may additionally include a storage device (e.g., a drive unit) 726, a signal generation device 728 (e.g., a speaker), a network interface device 720, and one or more sensors 722, such as a global positioning system (GPS) sensor, a compass, an accelerometer, or other sensors. Machine 700 may include an output controller 728, for example, a serial (e.g., Universal Serial Bus (USB), parallel, or other wired or wireless (e.g., infrared (IR), near field communication (NFC), etc.) connection to communicate with or control one or more peripheral devices (e.g., printers, card readers, etc.).

[0044] Storage device 726 may include a machine-readable medium 722 on which one or more sets of data structures or instructions 724 (e.g., software) are stored, said set of data structures or instructions 724 implementing or being used by any one or more of the techniques or functions described herein. The instructions 724 may also reside wholly or at least partially within main memory 704, static memory 706, or hardware processor 702 during execution by machine 700. In the example, one or any combination of hardware processor 702, main memory 704, static memory 707, or storage device 726 may constitute the machine-readable medium.

[0045] Although machine-readable medium 722 is shown as a single medium, the term "machine-readable medium" can include a single medium or multiple media (e.g., a centralized or distributed database and / or associated caches and servers) configured to store one or more instructions 724.

[0046] The term "machine-readable medium" can include any medium capable of storing, encoding, or carrying instructions for use by machine 700 and to cause machine 700 to perform any one or more of the techniques of this disclosure, or capable of storing, encoding, or carrying data structures used by or associated with such instructions. Examples of non-limiting machine-readable media can include solid-state memory as well as optical and magnetic media. Therefore, machine-readable media are not transiently propagating signals. Specific examples of high-capacity machine-readable media can include: non-volatile memory, such as semiconductor memory devices (e.g., electrically programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM)) and flash memory devices; magnetic or other phase-change or state-changing memory circuits; magnetic disks, such as internal hard disks and removable disks; magneto-optical disks; and CD-ROM and DVD-ROM disks.

[0047] Commands 724 can also be sent or received via the communication network 726 through the network interface device 720 using a transmission medium, utilizing any of several transport protocols (e.g., Frame Relay, Internet Protocol (IP), Transmission Control Protocol (TCP), User Datagram Protocol (UDP), Hypertext Transfer Protocol (HTTP), etc.). Example communication networks may include local area networks (LANs), wide area networks (WANs), packet data networks (e.g., the Internet), mobile phone networks (e.g., cellular networks), conventional telephone (POTS) networks, and wireless data networks (e.g., those referred to as…). The Institute of Electrical and Electronics Engineers (IEEE) 802.22 family of standards, known as The IEEE 802.26 family of standards, the IEEE 802.25.4 family of standards, peer-to-peer (P2P) networks, etc. are examples. In the example, network interface device 720 may include one or more physical jacks (e.g., Ethernet, coaxial, or telephone jacks) or one or more antennas for connecting to communication network 726. In the example, network interface device 720 may include multiple antennas to communicate wirelessly using at least one of single-input multiple-output (SIMO), multiple-input multiple-output (MIMO), or multiple-input single-output (MISO) technologies. The term "transmission medium" should be considered to include any intangible medium capable of storing, encoding, or carrying instructions for execution by machine 700 and including digital or analog communication signals, or other intangible media used to facilitate communication of such software.

[0048] Various annotations

[0049] Each of the above non-limiting aspects may exist independently, or may be combined in various permutations or combinations with one or more of the other aspects or other topics described herein.

[0050] The above detailed description includes reference to the accompanying drawings, which form part of the detailed description. The drawings illustrate, by way of illustration, specific implementations in which the invention can be practiced. These implementations are generally also referred to as "examples". Such examples may include elements other than those shown or described. However, the inventors also contemplate examples in which only those elements shown or described are provided. Furthermore, the inventors also contemplate examples (or one or more aspects thereof) using any combination or arrangement of those elements shown or described with respect to specific examples (or one or more aspects thereof) shown or described herein or with respect to other examples (or one or more aspects thereof).

[0051] In the event of any inconsistency between the usage in this document and any document incorporated by reference, the usage in this document shall prevail.

[0052] In this document, as is common in patent literature, the terms "a" or "an" are used to include one or more, independent of any other instances or uses of "at least one" or "one or more". In this document, unless otherwise indicated, the term "or" is used to refer to a non-exclusive "or", such that "A or B" includes "A but not B", "B but not A", and "A and B". In this document, the terms "including" and "in which" are used as concise English equivalents to the corresponding terms "comprising" and "wherein". Furthermore, in the appended claims, the terms "including" and "comprising" are open-ended, meaning that a system, apparatus, article, combination, formulation, or process that includes elements other than those listed after such terms in the claim is still considered to fall within the scope of that claim. Moreover, in the appended claims, the terms "first", "second", and "third", etc., are used only as denoting marks and are not intended to impose numerical requirements on their objects.

[0053] The methods described herein may be implemented, at least in part, by a machine or computer. Some examples may include computer-readable or machine-readable media encoded with instructions operable to configure an electronic device to perform the methods described in the examples above. Implementations of such methods may include code, such as microcode, assembly language code, higher-level language code, etc. Such code may include computer-readable instructions for performing various methods. The code may form part of a computer program product. Additionally, in the examples, the code may be tangibly stored on one or more volatile, non-transitory, or non-volatile tangible computer-readable media, for example, during execution or at other times. Examples of such tangible computer-readable media may include, but are not limited to, hard disks, removable disks, removable optical discs (e.g., compact discs and digital video discs), magnetic tape cartridges, memory cards or memory sticks, random access memory (RAM), read-only memory (ROM), etc.

[0054] The above description is intended to be illustrative and not restrictive. For example, the examples (or one or more aspects of the examples) described above can be used in combination with each other. Other implementations can be used by those skilled in the art after consulting the above description. An abstract is provided to enable the reader to quickly determine the nature of the disclosure. The abstract is submitted with the understanding that it is not intended to interpret or limit the scope or meaning of the claims. Furthermore, in the above detailed description, various features may be combined to simplify the disclosure. This should not be construed as meaning that any unclaimed disclosed feature is necessary for any claim. Rather, the subject matter of the invention may lie in fewer than all features of a particular disclosed implementation. Therefore, the appended claims are incorporated herein as examples or implementations, each claim existing independently as a separate implementation, and such implementations are contemplated to be combined with each other in various combinations or arrangements. The scope of the invention should be determined by reference to the appended claims and the full scope of their equivalents.< / r>

Claims

1. A method comprising: A TFM image representing defects in an object using a full-focusing method constructed at a first grid resolution; Based on the constructed TFM image, the centroid of the representation of the defect is determined; Based on the determined centroid, identify the major and minor axes of the defect's representation; Based on the TFM image, a plurality of pixel or voxel values ​​are determined along the major axis and the minor axis; as well as A second grid resolution corresponding to a specified amplitude fidelity is determined based on the plurality of pixel or voxel values ​​along the major axis and the minor axis.

2. The method according to claim 1, further comprising: Interpolation is applied to the plurality of pixel or voxel values ​​along the major axis and the minor axis.

3. The method according to claim 1 or 2, further comprising: The pixel or voxel values ​​along the major axis and the minor axis are normalized.

4. The method according to claim 1 or 2, wherein, Determining the second grid resolution includes: Based on the specified amplitude fidelity, calculate the width of the curve corresponding to the length of the axis of the target ellipse; and Calculate the second grid resolution such that at least three grid points fall along the target ellipse.

5. The method according to claim 1 or 2, further comprising: A second TFM image is constructed using the second grid resolution; as well as The amplitude fidelity value of the second TFM image is examined.

6. The method according to claim 5, wherein, The verification of the amplitude fidelity value includes: The amplitude fidelity value was verified by moving the grid of the second TFM image along multiple different directions.

7. The method according to claim 1 or 2, wherein, The first grid resolution is greater than the second grid resolution.

8. A machine storage medium including instructions that, when executed by a machine, cause the machine to perform operations, the operations including: A TFM image representing defects in an object using a full-focusing method constructed at a first grid resolution; Based on the constructed TFM image, the centroid of the representation of the defect is determined; Based on the determined centroid, identify the major and minor axes of the defect's representation; Based on the TFM image, a plurality of pixel or voxel values ​​are determined along the major axis and the minor axis; as well as A second grid resolution corresponding to a specified amplitude fidelity is determined based on the plurality of pixel or voxel values ​​along the major axis and the minor axis.

9. The machine storage medium according to claim 8, further comprising: Interpolation is applied to the plurality of pixel or voxel values ​​along the major axis and the minor axis.

10. The machine storage medium according to claim 8 or 9, further comprising: The plurality of pixel or voxel values ​​along the major axis and the minor axis are normalized.

11. The machine storage medium according to claim 8 or 9, wherein, Determining the second grid resolution includes: Based on the specified amplitude fidelity, calculate the width of the curve corresponding to the length of the axis of the target ellipse; and Calculate the second grid resolution such that at least three grid points fall along the target ellipse.

12. The machine storage medium according to claim 8 or 9, further comprising: A second TFM image is constructed using the second grid resolution; as well as The amplitude fidelity value of the second TFM image is examined.

13. The machine storage medium according to claim 12, wherein, The verification of the amplitude fidelity value includes: The amplitude fidelity value was verified by moving the grid of the second TFM image along multiple different directions.

14. The machine storage medium according to claim 8 or 9, wherein, The first grid resolution is greater than the second grid resolution.

15. A system comprising: One or more processors in a machine; as well as A memory storing instructions that, when executed by the one or more processors, cause the machine to perform operations, including: A TFM image representing defects in an object using a full-focusing method constructed at a first grid resolution; Based on the TFM image, determine the centroid of the representation of the defect; Based on the determined centroid, identify the major and minor axes of the defect's representation; Based on the TFM image, determine multiple pixel or voxel values ​​along the major and minor axes; and A second grid resolution corresponding to a specified amplitude fidelity is determined based on the plurality of pixel or voxel values ​​along the major axis and the minor axis.

16. The system of claim 15, further comprising: Interpolation is applied to the plurality of pixel or voxel values ​​along the major axis and the minor axis.

17. The system according to claim 15 or 16, wherein the operation further comprises: The plurality of pixel or voxel values ​​along the major axis and the minor axis are normalized.

18. The system according to claim 15 or 16, wherein, Determining the second grid resolution includes: Based on the specified amplitude fidelity, calculate the width of the curve corresponding to the length of the axis of the target ellipse; and Calculate the second grid resolution such that at least three grid points fall along the target ellipse.

19. The system according to claim 15 or 16, wherein the operation further comprises: A second TFM image is constructed using the second grid resolution; as well as The amplitude fidelity value of the second TFM image is examined.

20. The system according to claim 19, wherein, The verification of the amplitude fidelity value includes: The amplitude fidelity value was verified by moving the grid of the second TFM image along multiple different directions.

21. The system according to claim 15 or 16, wherein, The first grid resolution is greater than the second grid resolution.

Images