CA-3217829-C - ADAPTIVE ULTRASONIC INSPECTION FOR VOLUMETRIC FLAWS

Abstract

Acoustic evaluation of a target can be performed using an array of electro-acoustic transducers. For example, a technique for such evaluation can include generating acoustic transmission events using different transmitting apertures, the apertures defined by corresponding zones along the array, the zones including multiple electro-acoustic transducer elements. In response to the respective acoustic transmission events, respective acoustic echo signals are received. Representations of the respective received acoustic echo signals are coherently summed. The coherently summing includes applying determined nominal element delay factors to the respective representations to approximate a virtual probe normal to a nominal shape of a surface of a structure being inspected. A pixel or voxel value is corresponding to a specified spatial location within the structure being inspected is generated using the coherently summed representations.

Inventors

• Benoit Lepage
• Jinchi Zhang

Assignees

• EVIDENT CANADA, INC.

Dates

Publication Date

20260505

Application Date

20220426

Priority Date

20210430

Claims (3)

1. THE CLAIMED INVENTION IS: 1. 5 10 15 20 25 30 A machine-implemented method for acoustic evaluation of a target using an array of electro-acoustic transducers, the method comprising: generating respective acoustic transmission events using different transmitting apertures, the apertures defined by corresponding zones along the array, the zones including multiple electro-acoustic transducer elements; in response to the respective acoustic transmission events, receiving respective acoustic echo signals, using receiving ones of the electro-acoustic transducer elements, to form a group of received acoustic echo signals, the group indexed by transmit-receive pairs including a respective transmit zone and a respective one of the receiving elements; coherently summing representations of the respective received acoustic echo signals, the representations corresponding to the respective transmit-receive pairs, the coherently summing including applying determined nominal element delay factors to the respective representations to approximate a virtual probe normal to a nominal shape of a surface of a structure being inspected, and applying respective delay factor corrections to compensate for variation from the nominal shape or a nominal alignment of the surface of the structure with respect to the array of electro-acoustic transducers; and generating a pixel or voxel value corresponding to a specified spatial location within the structure being inspected using the coherently summed representations.
2. 2. The machine-implemented method of claim 1, wherein generating the respective acoustic transmission events comprises generating at least three acoustic transmission events using different transmitting apertures corresponding to different zones.
3. 3. The machine-implemented method of claim 2, wherein the zones partially overlap. 23 4. The machine-implemented method of any one of claims 1 through 3, comprising determining the respective delay factor corrections using a single iteration. 5 10 15 20 25 5. The machine-implemented method of any one of claims 1 through 4, comprising determining the respective delay factors using respective apertures comprising two or more electro-acoustic transducer elements. 6. The machine-implemented method of any one of claims 1 through 5, wherein the representations of the respective received acoustic echo signals comprise A-scan representations. 7. The machine-implemented method of claim 6, wherein generating a pixel or voxel value corresponding to a specified spatial location on or within the structure being inspected includes generating an image of multiple spatial locations using respective coherent summations, the respective coherent summations including applying the determined nominal element delay factors and applying the respective delay factor corrections. 8. The machine-implemented method of claim 7, wherein the structure under test is a bar. 9. The machine-implemented method of claim 8, wherein the image represents a sector within a volume of the bar. 10. The machine-implemented method of claim 9, comprising performing another acquisition to form another group of received acoustic echo signals, the group indexed by transmit-receive pairs including the respective transmit zone and a respective one of the receiving elements, to generate another image of a different sector within the volume of the bar. 11. The machine-implemented method of claim 10, wherein the performing another acquisition includes re-positioning the array or the structure under test to 24 allow insonification of a different portion of a surface of the structure under test by the array. 12. 5 10 15 The machine-implemented method of claim 10, wherein the performing another acquisition includes using a second array configured to insonify a different portion of a surface of the structure under test. 13. The machine-implemented method of any one of claims 1 through 12, comprising generating an acoustic transmission event to excite a shear wave for imaging of a surface of the structure under test; and wherein imaging the surface of the structure under test comprises coherently summing representations of respective received acoustic echo signals, and applying the determined nominal element delay factors to the respective representations to approximate a beam normal to the nominal shape of the surface of the structure being inspected, and applying respective delay factor corrections to compensate for variation from the nominal shape or the nominal alignment of the surface of the structure with respect to the array of electro-acoustic transducers; and generating a pixel or voxel value corresponding to a specified spatial location on the structure being inspected using the coherently summed representations. 14. An ultrasonic inspection system for acoustic evaluation of a target using an array of electro-acoustic transducers, the system comprising: an analog front end comprising transmit and receive circuitry coupled to the array of electro-acoustic transducer elements; a processor circuit communicatively coupled with the analog front end; an a memory circuit comprising instructions that, when executed by the processor circuit, cause the system to: generate respective acoustic transmission events using different transmitting apertures, the apertures defined by corresponding zones along the array, the zones including multiple electro-acoustic transducer elements; in response to the respective acoustic transmission events, receive respective acoustic echo signals, using receiving ones of the electro-acoustic transducer elements, to form a group of received acoustic echo signals, the 25 group indexed by transmit-receive pairs including a respective transmit zone and a respective one of the receiving elements; coherently sum representations of the respective received acoustic echo signals, the representations corresponding to the respective transmit-receive pairs, the coherently summing including applying determined nominal element delay factors to the respective representations to approximate a beam normal to a nominal shape of a surface of a structure being inspected, and applying respective delay factor corrections to compensate for variation from the nominal shape or a nominal alignment of the surface of the structure with respect to the array of electro-acoustic transducers; and generate a pixel or voxel value corresponding to a specified spatial location within the structure being inspected using the coherently summed representations. 15. 5 10 15 The ultrasonic inspection system of claim 14, wherein the instructions to generate the respective acoustic transmission events comprises instructions to generate at least three acoustic transmission events using different transmitting apertures corresponding to different zones. 16. The ultrasonic inspection system of claim 15, wherein the zones partially overlap. 17. The ultrasonic inspection system of any one of claims 14 through 16, further comprising instructions to determine the respective delay factor corrections using a single iteration. 18. The ultrasonic inspection system of any one of claims 14 through 17, comprising determining the respective delay factors using respective apertures comprising two or more electro-acoustic transducer elements. 19. The ultrasonic inspection system of any one of claims 14 through 18, wherein the representations of the respective received acoustic echo signals comprise A-scan representations. 26 20. 5 10 15 20 25 30 The ultrasonic inspection system of claim 19, wherein the instructions to generate a pixel or voxel value corresponding to a specified spatial location on or within the structure being inspected includes instructions to generate an image of multiple spatial locations using respective coherent summations, the respective coherent summations including applying the determined nominal element delay factors and applying the respective delay factor corrections. 21. The ultrasonic inspection system of claim 20, wherein the structure under test is a bar. 22. The ultrasonic inspection system of claim 21, wherein the image represents a sector within a volume of the bar. 23. The ultrasonic inspection system of claim 22, comprising instructions to perform another acquisition to form another group of received acoustic echo signals, the group indexed by transmit-receive pairs including the respective transmit zone and a respective one of the receiving elements, to generate another image of a different sector within the volume of the bar. 24. The ultrasonic inspection system of claim 23, wherein the instructions to perform another acquisition includes instructions to re-position the array or the structure under test to allow insonification of a different portion of a surface of the structure under test by the array. 25. The ultrasonic inspection system of claim 24, wherein the instructions to perform another acquisition includes instructions to use a second array configured to insonify a different portion of a surface of the structure under test. 26. The ultrasonic inspection system of any one of claims 14 through 25, comprising: instructions to generate an acoustic transmission event to excite a shear wave for imaging of a surface of the structure under test; and 27 5 10 15 20 25 30 wherein imaging the surface of the structure under test comprises coherently summing representations of respective received acoustic echo signals, and applying the determined nominal element delay factors to the respective representations to approximate a beam normal to the nominal shape of the surface of the structure being inspected, and applying respective delay factor corrections to compensate for variation from the nominal shape or the nominal alignment of the surface of the structure with respect to the array of electro-acoustic transducers; and instructions to generate a pixel or voxel value corresponding to a specified spatial location on the structure being inspected using the coherently summed representations. 27. An ultrasonic inspection system for acoustic evaluation of a target using an array of electro-acoustic transducers, comprising: a means for generating respective acoustic transmission events using different transmitting apertures, the apertures defined by corresponding zones along the array, the zones including multiple electro-acoustic transducer elements; in response to the respective acoustic transmission events, means for receiving respective acoustic echo signals, using receiving ones of the electro-acoustic transducer elements, to form a group of received acoustic echo signals, the group indexed by transmit-receive pairs including a respective transmit zone and a respective one of the receiving elements; a means for coherently summing representations of the respective received acoustic echo signals, the representations corresponding to the respective transmit receive pairs, the coherently summing including applying determined nominal element delay factors to the respective representations to approximate a beam normal to a nominal shape of a surface of a structure being inspected, and applying respective delay factor corrections to compensate for variation from the nominal shape or a nominal alignment of the surface of the structure with respect to the array of electro acoustic transducers a means for generating a pixel or voxel value corresponding to a specified spatial location within the structure being inspected using the coherently summed representations. 28

Description

1 ADAPTIVE ULTRASONIC INSPECTION FOR VOLUMETRIC FLAWS FIELD 5 OF THE DISCLOSURE [0002] This document pertains generally, but not by way of limitation, to nondestructive evaluation, and more particularly, to apparatus and techniques for providing acoustic inspection in adaptive manner for detecting subsurface or internal defects in structures such as bars. 10 BACKGROUND [0003] Various inspection techniques can be used to image or otherwise analyze structures without damaging such structures. For example, one or more of x-ray inspection, eddy current inspection, or acoustic (e.g., ultrasonic) inspection can be used to obtain data for imaging of features on or within a test specimen. For example, 15 acoustic imaging can be performed using an array of ultrasound transducer elements, such as to image a region of interest within a test specimen. SUMMARY OF THE DISCLOSURE [0004] Acoustic inspection can be used to detect volumetric or near-surface flaws in a 20 non-destructive manner. For example, in bar inspection, sets of ultrasonic inspection probes can be located at various positions radially around a bar under test. Volumetric scan can be performed by acquiring B-Scan imaging data comprising a series of stacked E-Scan images. Such an approach can present various challenges, such as producing imaging that does not represent a flaw location in a manner corresponding 25 to the actual physical location of the flaw. Such imaging may also be prone to masking or suppressing flaw identification in the presence of misalignment between the probe assembly and the bar under test. The present inventors have recognized, among other things, that an adaptive approach can be used to determine individual probe element delay compensation values to compensate for misalignment, and a zonal imaging approach can be used including a sparse matrix acquisition scheme (referred to herein as zonal Dynamic Depth Focusing) that can provide imaging that more meaningfully represents a physical flaw location. Various examples described herein may also be used for shear wave imaging, such as for back-wall surface or 5 near-surface flaw inspection. [0005] In an example, acoustic evaluation of a target can be performed using an array of electro-acoustic transducers. For example, a technique for such evaluation can include generating respective acoustic transmission events using different transmitting apertures, the apertures defined by corresponding zones along the array, the zones 10 include multiple electro-acoustic transducer elements. In response to the respective acoustic transmission events, respective acoustic echo signals are received, using receiving ones of the electro-acoustic transducer elements, to form a group of received acoustic echo signals. For example, the group is indexed by transmit-receive pairs including a respective transmit zone and a respective one of the receiving 15 elements. Representations of the respective received acoustic echo signals are coherently summed. The representations correspond to the respective transmitreceive pairs. The coherently summing including applying determined nominal element delay factors to the respective representations to approximate a virtual probe normal to a nominal shape of a surface of a structure being inspected. Respective 20 delay factor corrections are applied to compensate for variation from the nominal shape or a nominal alignment of the surface of the structure with respect to the array of electro-acoustic transducers. A pixel or voxel value is corresponding to a specified spatial location within the structure being inspected is generated using the coherently summed representations. 25 [0006] In an example, an ultrasonic inspection system for acoustic evaluation of a target uses an array of electro-acoustic transducers. An analog front end comprising transmit and receive circuitry is coupled to the array of electro-acoustic transducer elements. A processor circuit is communicatively coupled with the analog front end. A memory circuit comprising instructions that, when executed by the processor 30 circuit, cause the system to perform tasks. For example, the instructions include generating respective acoustic transmission events using different transmitting apertures, the apertures defined by corresponding zones along the array, the zones include multiple electro-acoustic transducer elements. In response to the respective 2 acoustic transmission events, respective acoustic echo signals are received, using receiving ones of the electro-acoustic transducer elements, to form a group of received acoustic echo signals. For example, the group is indexed by transmit-receive pairs including a respective transmit zone and a respective one of the receiving 5 elements. Representations of the respective received acoustic echo signals are coherently summed. The representations correspond to the respective transmitreceive pairs. The coherently summing including applying determined nominal elem