Dry-type bushing defect detection method and system based on ultrasonic phased array

Abstract

The invention relates to the technical field of ultrasonic defect detection, in particular to a dry-type sleeve defect detection method and system based on an ultrasonic phased array, and the method comprises the steps: obtaining a sonic path distance from each pixel point in single plane wave imaging corresponding to each deflection angle to each transmitting array element and each receiving array element, obtaining the total flight time from each pixel point to each transmitting array element and each receiving array element in single plane wave imaging according to the sound path distance and the focusing delay of each transmitting array element; obtaining full-matrix data according to the total flight time; obtaining the superposed signal intensity of each pixel point in the single plane wave imaging corresponding to each deflection angle, and obtaining a weighted composite image through weighting; performing post-processing and segmentation on the weighted composite image to obtain a plurality of new connected domains; and screening out bubble defect connected domains from all the new connected domains through the new connected domain areas. According to the invention, the accuracy of defect detection of the dry-type bushing is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of ultrasonic defect detection, and in particular to a dry casing defect detection method and system based on an ultrasonic phased array. Background Art

[0002] Dry-type bushings are widely used in the power industry due to their excellent insulation performance. However, their manufacturing process is complex. During the manufacturing process, defects such as bubbles and gaps are easily generated inside the dry-type bushings, resulting in a decrease in insulation performance and threatening equipment safety. Therefore, in order to ensure that the produced dry-type bushings are free of defects such as bubbles and gaps, it is necessary to randomly select individual dry-type bushings and perform slicing sampling to conduct defect detection on the dry-type bushings.

[0003] Conventional ultrasonic phased array testing (PAUT) can be used to inspect dry-type bushings for defects. Ultrasonic phased array testing (PAUT) is an efficient and accurate nondestructive testing method that uses ultrasonic principles to detect material or equipment defects. It is commonly used for inspecting metals, welds, and composite materials. However, due to the influence of bubbles and irregular gaps, conventional ultrasonic phased array testing can interfere with the ultrasonic signal during defect detection, resulting in reflected signals that prevent the precise location of the bubbles. Therefore, an improved ultrasonic phased array testing method is used to detect dry-type bushing defects. Summary of the Invention

[0004] The present invention provides a dry casing defect detection method and system based on ultrasonic phased array, which are used to solve the existing problem of bubble interference on signals.

[0005] The purpose of the present invention can be achieved through the following technical solutions: A first aspect of the present invention is to provide a dry casing defect detection method based on an ultrasonic phased array, comprising: Acquire a plane wave deflection angle sequence consisting of several plane wave deflection angles; obtain full matrix data corresponding to each deflection angle in the plane wave deflection angle sequence through an ultrasonic phased array detection system; and obtain the focusing delay of each transmitting array element at each deflection angle; Obtain a single plane wave imaging corresponding to each deflection angle in a deflection angle sequence; obtain an acoustic path from each pixel point to each transmitting array element and each receiving array element in the single plane wave imaging corresponding to each deflection angle, and obtain a total flight time from each pixel point to each transmitting array element and each receiving array element in the single plane wave imaging based on the acoustic path and the focusing delay of each transmitting array element; obtain full matrix data corresponding to the single plane wave imaging corresponding to each deflection angle based on the total flight time; obtain a superimposed signal intensity of each pixel point in the single plane wave imaging corresponding to each deflection angle; obtain a coherence factor of the pixel point corresponding to each position based on the superimposed signal intensity of the pixel point at the same position in the single plane wave imaging corresponding to all deflection angles in the deflection angle sequence; adjust the superimposed signal intensity of the pixel point at the same position in the single plane wave imaging corresponding to all deflection angles in the deflection angle sequence using the coherence factor to obtain a weighted composite image; The weighted composite image is enhanced to obtain an enhanced composite image; the enhanced composite image is segmented to obtain a plurality of new connected domains; and the bubble defect connected domain is screened out from all the new connected domains according to the area of the new connected domains.

[0006] Furthermore, obtaining the focusing delay of each transmitting array element at each deflection angle includes:

[0007] Where, Indicates the The transmission deflection angle of the transmitting array element, represents the speed of sound in the medium, Indicates the The focusing delay of each transmitting element, Indicates the The distance between the transmitting element and the center of the array.

[0008] Furthermore, the step of obtaining a single plane wave image corresponding to each deflection angle in the deflection angle sequence; obtaining an acoustic path from each pixel point to each transmitting array element and each receiving array element in the single plane wave image corresponding to each deflection angle, and obtaining a total flight time from each pixel point to each transmitting array element and each receiving array element in the single plane wave image based on the acoustic path and the focusing delay of each transmitting array element includes: The single plane wave imaging corresponding to each deflection angle in the deflection angle sequence is obtained by plane wave composite imaging algorithm;

[0009]

[0010] Where, Represents the coordinates of a pixel point in single plane wave imaging, Represents the transmitting array element The coordinates of Receiving array element coordinates of Represents the distance from each pixel to the transmitting array element in single plane wave imaging The sound distance between Represents the distance from each pixel to the receiving array element in single plane wave imaging The sound distance between

[0011] Where, Represents the transmitting array element Focus delay, represents the longitudinal wave speed of sound, Represents the distance from each pixel to the transmitting array element in single plane wave imaging and receiving array elements total flight time.

[0012] Furthermore, the method of obtaining the superimposed signal intensity of each pixel in the single plane wave imaging corresponding to each deflection angle based on the total flight time and the full matrix data corresponding to the single plane wave imaging corresponding to each deflection angle includes:

[0013] Where, Represents the distance from each pixel to the transmitting array element in single plane wave imaging and receiving array elements Total flight time, Indicates Find the corresponding signal intensity in the full matrix data for the index; represents the total number of transmitting array elements, Represents the total number of receiving array elements, Represents the superimposed signal intensity of each pixel in the single plane wave imaging corresponding to each deflection angle.

[0014] Furthermore, obtaining the coherence factor of the pixel corresponding to each position according to the superimposed signal intensities of the pixel at the same position in the single plane wave imaging corresponding to all deflection angles in the deflection angle sequence includes:

[0015] Where, Indicates the first The position coordinates in single plane wave imaging corresponding to the deflection angle are: The superimposed signal strength of the corresponding pixel point, Indicates the number of all deflection angles in the deflection angle sequence, Indicates the absolute value symbol, The position coordinates are The coherence factor of the corresponding pixel.

[0016] Furthermore, the coherence factor is used to adjust the superimposed signal intensity of the pixel points at the same position in the single plane wave imaging corresponding to all deflection angles in the deflection angle sequence to obtain a weighted composite image, including:

[0017] Where, Indicates the first The position coordinates in single plane wave imaging corresponding to the deflection angle are: The superimposed signal strength of the corresponding pixel point, Indicates the number of all deflection angles in the deflection angle sequence, The position coordinates are The coherence factor of the corresponding pixel point, Indicates that the position coordinates in the fused image are The superimposed signal intensity of the corresponding pixel; A weighted composite image is formed by superimposing the signal intensities of the corresponding pixels at all positions in the fused image.

[0018] Furthermore, the weighted composite image is enhanced to obtain an enhanced composite image; the enhanced composite image is segmented to obtain a plurality of new connected domains; and bubble defect connected domains are screened out from all the new connected domains by the area of the new connected domains, including: The weighted composite image is enhanced by a linear enhancement algorithm to obtain an enhanced composite image. The enhanced composite image is segmented by semantic segmentation to obtain several connected domains. The neural network structure corresponding to semantic segmentation is a U-Net network, and the SE Block channel attention module is embedded in the skip connection of the U-Net network. A morphological closing operation is performed on several connected domains to obtain several new connected domains after processing; the areas of all the new connected domains are linearly normalized to obtain the normalized areas of the new connected domains; and the new connected domains whose normalized areas are smaller than a preset first reference area threshold and larger than a preset second reference area threshold in all the new connected domains are regarded as bubble defect connected domains.

[0019] A second aspect of the present invention is to provide a dry casing defect detection system based on an ultrasonic phased array, comprising: Data acquisition module: used to obtain a plane wave deflection angle sequence consisting of several plane wave deflection angles; obtain the full matrix data corresponding to each deflection angle in the plane wave deflection angle sequence through the ultrasonic phased array detection system; obtain the focusing delay of each transmitting array element at each deflection angle; Image fusion module: used to obtain the single plane wave imaging corresponding to each deflection angle in the deflection angle sequence; obtain the acoustic path between each pixel point and each transmitting array element and each receiving array element in the single plane wave imaging corresponding to each deflection angle, and obtain the total flight time from each pixel point to each transmitting array element and each receiving array element in the single plane wave imaging according to the acoustic path and the focusing delay of each transmitting array element; obtain the full matrix data corresponding to the single plane wave imaging corresponding to each deflection angle according to the total flight time; obtain the superimposed signal intensity of each pixel point in the single plane wave imaging corresponding to each deflection angle; obtain the coherence factor of the pixel point corresponding to each position according to the superimposed signal intensity of the pixel point at the same position in the single plane wave imaging corresponding to all deflection angles in the deflection angle sequence; adjust the superimposed signal intensity of the pixel point at the same position in the single plane wave imaging corresponding to all deflection angles in the deflection angle sequence according to the coherence factor to obtain a weighted composite image; Defect detection module: used to enhance the weighted composite image to obtain an enhanced composite image; segment the enhanced composite image to obtain several new connected domains; and filter out bubble defect connected domains from all new connected domains based on the area of the new connected domains.

[0020] A third aspect of the present invention is to provide an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the dry casing defect detection method based on an ultrasonic phased array is implemented.

[0021] A fourth aspect of the present invention is to provide a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the dry casing defect detection method based on ultrasonic phased array is implemented.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows: obtaining the acoustic path from each pixel point to each transmitting array element and each receiving array element in the single plane wave imaging corresponding to each deflection angle, obtaining the total flight time from each pixel point to each transmitting array element and each receiving array element in the single plane wave imaging based on the acoustic path and the focusing delay of each transmitting array element, thereby improving the accuracy of ultrasonic time analysis; obtaining the superimposed signal intensity of each pixel point in the single plane wave imaging corresponding to each deflection angle based on the total flight time and the full matrix data corresponding to the single plane wave imaging corresponding to each deflection angle, thereby improving the accuracy of superimposed signal intensity analysis; and obtaining the superimposed signal intensity of each pixel point in the single plane wave imaging corresponding to each deflection angle based on the full matrix data corresponding to the single plane wave imaging corresponding to each deflection angle. The coherence factor of the pixel point corresponding to each position is obtained by superimposing the signal intensity of the pixel points at the same position in the single plane wave imaging corresponding to the deflection angle; the superimposed signal intensity of the pixel points at the same position in the single plane wave imaging corresponding to all deflection angles in the deflection angle sequence is adjusted by the coherence factor to obtain a weighted composite image, thereby improving the accuracy of weighted fusion of multiple images; the weighted composite image is enhanced to obtain an enhanced composite image; the enhanced composite image is segmented to obtain several new connected domains, thereby improving the accuracy of image post-processing; and the bubble defect connected domain is screened out from all the new connected domains by the area of the new connected domain, thereby improving the accuracy of dry casing defect detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0024] Figure 1 The present invention provides a schematic flow chart of the steps of a dry casing defect detection method based on an ultrasonic phased array; Figure 2 The present invention provides a module flow diagram of a dry casing defect detection system based on ultrasonic phased array; Figure 3 This is a schematic diagram of the dry casing defect detection process; Figure 4 Schematic diagram of dry cannula before and after imaging; Figure 5 Schematic diagram of dry casing defect detection. DETAILED DESCRIPTION

[0025] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0026] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0027] In response to the problems existing in the background technology, a dry casing defect detection method and system based on ultrasonic phased array was studied and designed, which has important practical significance.

[0028] like Figure 1 As shown, the first aspect of the present invention is to provide a dry casing defect detection method based on ultrasonic phased array, comprising the following steps: Step S001: Build an ultrasonic phased array detection system, obtain full matrix data of dry casing slices through the ultrasonic phased array detection system, and obtain the focusing delay of each transmitting array element at each deflection angle.

[0029] It should be noted that in order to detect defects such as bubbles and gaps that are easily generated inside the dry-type casing during the manufacturing process, it is necessary to collect initial images of slices of the dry-type casing to perform abnormal defect detection.

[0030] Specifically, impurities such as oil on the surface of dry casing slices were first removed. Then, an ultrasonic phased array detection system was constructed, which included a phased array probe, a signal generator, a data acquisition module, and an imaging processing unit. Water was used as an ultrasonic coupling agent between the dry casing slices and the ultrasonic phased array wedge to reduce wave loss.

[0031] The signal generator generates high-precision excitation pulses to control the formation of the acoustic beam, and then the phased array probe transmits plane waves to the dry casing. The data acquisition module collects the echo signal, completes the digital processing, and obtains the full matrix data of the dry casing slice. Among them, the number of array elements in the Chinese and Russian ultrasonic phased array is 64, the center frequency is 5MHz, and the medium sound velocity is , the coupling medium is water, and the scanning mode is A-scan.

[0032] It should be noted that in order to optimize imaging quality, increase image resolution, and improve signal-to-noise ratio, multiple deflection angles are introduced during plane wave emission to improve image clarity.

[0033] Specifically, multiple deflection angles are introduced to form a plane wave deflection angle sequence; in this embodiment, the plane wave deflection angle sequence is ; Obtain the full matrix data corresponding to each deflection angle in the plane wave deflection angle sequence. Among them, the deflection angle during plane wave emission is determined by the focusing delay of plane wave imaging; Among them, the formula corresponding to the focusing delay of plane wave imaging is:

[0034] Where, Indicates the The transmission deflection angle of the transmitting array element, represents the speed of sound in the medium, Indicates the The focusing delay of each transmitting element, Indicates the The distance between the transmitting element and the center of the array.

[0035] Step S002: Acquire single plane wave imaging through full matrix data, and fuse all single plane wave imaging to obtain a weighted composite image.

[0036] A single plane wave image corresponding to each deflection angle in the deflection angle sequence is obtained using a plane wave composite imaging algorithm. Thus, single plane wave images corresponding to all deflection angles in the deflection angle sequence are obtained. Then, the single plane wave images corresponding to all deflection angles in the deflection angle sequence are combined using an all-focusing algorithm to obtain a final all-focused image. The specific process of obtaining the all-focused image using the all-focusing algorithm is as follows: Obtain the acoustic path from each pixel point to each transmitting array element and each receiving array element in the single plane wave imaging corresponding to each deflection angle; specifically, it can be expressed as follows:

[0037]

[0038] Where, Represents the coordinates of a pixel point in single plane wave imaging, Represents the transmitting array element The coordinates of Receiving array element coordinates of Represents the distance from each pixel to the transmitting array element in single plane wave imaging The sound distance between Represents the distance from each pixel to the receiving array element in single plane wave imaging The sound distance between them.

[0039] The total flight time from each pixel point to each transmitting array element and each receiving array element in the single plane wave imaging corresponding to each deflection angle is obtained based on the acoustic path from each pixel point to each transmitting array element and each receiving array element and the focusing delay of each transmitting array element. The total flight time is specifically expressed by the formula:

[0040] Where, Represents the transmitting array element Focus delay, represents the longitudinal wave speed of sound, Represents the distance from each pixel to the transmitting array element in single plane wave imaging and receiving array elements total flight time.

[0041] According to the total flight time from each pixel point to each transmitting array element and each receiving array element in the single plane wave imaging and the full matrix data corresponding to the single plane wave imaging, the superimposed signal intensity of each pixel point in the single plane wave imaging corresponding to each deflection angle is obtained; the superimposed signal intensity of each pixel point in the single plane wave imaging is specifically expressed by the formula:

[0042] Where, Represents the distance from each pixel to the transmitting array element in single plane wave imaging and receiving array elements Total flight time, Indicates Find the corresponding signal intensity in the full matrix data for the index; represents the total number of transmitting array elements, Represents the total number of receiving array elements, Represents the superimposed signal intensity of each pixel in the single plane wave imaging corresponding to each deflection angle.

[0043] The coherence factor of the pixel corresponding to each position is obtained based on the superimposed signal intensity of the pixel at the same position in the single plane wave imaging corresponding to all deflection angles in the deflection angle sequence. The coherence factor is specifically expressed by the formula:

[0044] Where, Indicates the first The position coordinates in single plane wave imaging corresponding to the deflection angle are: The superimposed signal strength of the corresponding pixel point, Indicates the number of all deflection angles in the deflection angle sequence, Indicates the absolute value symbol, The position coordinates are The coherence factor of the corresponding pixel.

[0045] The superimposed signal intensity of the pixel points at the same position in the single plane wave imaging corresponding to all deflection angles in the deflection angle sequence is adjusted by the coherence factor of the pixel points corresponding to each position to obtain the superimposed signal intensity of the pixel points corresponding to each position in the fused image. The superimposed signal intensity of the pixel points corresponding to each position in the fused image is specifically expressed by the formula:

[0046] Where, Indicates the first The position coordinates in single plane wave imaging corresponding to the deflection angle are: The superimposed signal strength of the corresponding pixel point, Indicates the number of all deflection angles in the deflection angle sequence, The position coordinates are The coherence factor of the corresponding pixel point, Indicates that the position coordinates in the fused image are The superimposed signal intensity of the corresponding pixel point.

[0047] The weighted composite image is formed by superimposing the signal intensities of the corresponding pixels at all positions in the weighted composite image. Figure 4 As shown. Among them, Figure 4It can be seen that neither the TFM (Total Focusing Method) image nor the coherence factor image effectively suppresses sidelobe signals, but instead expands the range of artifacts and significantly attenuates the mainlobe signal, thereby weakening the discernibility of defect features. The weighted TFM image, however, achieves intelligent sidelobe suppression and directional enhancement of the mainlobe signal, clearly revealing the contours of tiny defects and accurately analyzing their spatial distribution parameters, achieving optimal detection results. The weighted TFM image is a weighted composite image.

[0048] So far, a weighted composite image is obtained through the above method.

[0049] Step S003: Post-processing and segmenting the weighted composite image to obtain several new connected domains; and screening out bubble defect connected domains from all the new connected domains by using the area of the new connected domains.

[0050] It should be noted that, since there is a certain amount of noise interference in the surrounding environment during the process of acquiring the weighted composite image, in order to improve the accuracy of the image information, the weighted composite image needs to be enhanced.

[0051] Specifically, the weighted composite image is enhanced by a linear enhancement algorithm to obtain an enhanced composite image; wherein the linear enhancement algorithm is a well-known technology and will not be described in detail here.

[0052] The enhanced composite image is then segmented by semantic segmentation to obtain several connected domains; wherein, in this embodiment, the neural network structure corresponding to the semantic segmentation is a U-Net network, wherein, in this embodiment, the loss function of the U-Net network (U-type network) is a cross-entropy loss function; wherein the U-Net network and the cross-entropy loss function are both well-known technologies and will not be described in detail here.

[0053] Among them, the U-Net network contains structures such as encoder, decoder and skip connection; among them, the SE Block (Squeeze-and-Excitation Block) channel attention module is embedded in the skip connection to enhance the feature weight of the defect area.

[0054] Here, edges, textures, colors, shapes, and gradients are used as channels to determine the corresponding convolution kernels, and the corresponding feature maps are obtained using specific convolution kernels. Edges and gradients are obtained using the Sobel operator; the Sobel operator is well-known and will not be described in detail here.

[0055] At this point, the above-mentioned U-Net network usually obtains several connected domains in the enhanced composite image.

[0056] Perform morphological closing operations on several connected domains to obtain several new connected domains after processing; among them, the morphological closing operation is to expand the foreground area through the dilation operation, and then restore the main structure of the image through the erosion operation, which plays the role of filling small holes and removing small noise points.

[0057] The morphological closing operation is a well-known technology and will not be described in detail here.

[0058] It should be noted that, in order to prevent the interference of the connected domains corresponding to the isolated noise points, it is also necessary to screen out the connected domains corresponding to the isolated noise points.

[0059] It should be further explained that, since the areas of the connected domains corresponding to bubble defects and the connected domains corresponding to isolated noise points are relatively small, they can be screened out by the area of the connected domains; and because the area of the connected domains corresponding to isolated noise points is smaller than that of the connected domains corresponding to bubble defects, bubble defects are screened by setting two area thresholds.

[0060] Specifically, the areas of all new connected domains are linearly normalized to obtain the normalized areas of the new connected domains; the normalized areas of all new connected domains that are smaller than the preset first reference area threshold are normalized. and is greater than the preset second reference area threshold The new connected domain is used as the bubble defect connected domain.

[0061] In this embodiment, a first reference area threshold is preset. , preset the second reference area threshold , wherein in this embodiment, a first reference area threshold is preset and preset second reference area threshold There is no specific limitation and implementers can decide based on specific circumstances.

[0062] So far, the defect bubble connected domain is obtained through the above method. Among them, the dry casing defect detection process diagram is as follows Figure 3 As shown in the figure. Among them, the schematic diagram of dry casing defect detection is as follows Figure 5 As shown. Among them, Figure 5 In the figure, the casing is displayed as a small green cloud due to its multi-layer structure and other minor defects; blue represents the basic low-amplitude echo signal, indicating no defects; red represents the high-amplitude ultrasonic echo signal, indicating the presence of various defects or inclusions.

[0063] like Figure 2 As shown, the second aspect of the present invention is to provide a dry casing defect detection system based on ultrasonic phased array, including the following modules: Data acquisition module 101: used to obtain a plane wave deflection angle sequence consisting of a plurality of plane wave deflection angles; obtain full matrix data corresponding to each deflection angle in the plane wave deflection angle sequence through an ultrasonic phased array detection system; and obtain the focusing delay of each transmitting array element at each deflection angle; Image fusion module 102: used to obtain the single plane wave imaging corresponding to each deflection angle in the deflection angle sequence; obtain the acoustic path from each pixel point to each transmitting array element and each receiving array element in the single plane wave imaging corresponding to each deflection angle, and obtain the total flight time from each pixel point to each transmitting array element and each receiving array element in the single plane wave imaging based on the acoustic path and the focusing delay of each transmitting array element; obtain the superimposed signal intensity of each pixel point in the single plane wave imaging corresponding to each deflection angle based on the total flight time and the full matrix data corresponding to the single plane wave imaging corresponding to each deflection angle; obtain the coherence factor of the pixel point corresponding to each position based on the superimposed signal intensity of the pixel points at the same position in the single plane wave imaging corresponding to all deflection angles in the deflection angle sequence; adjust the superimposed signal intensity of the pixel points at the same position in the single plane wave imaging corresponding to all deflection angles in the deflection angle sequence based on the coherence factor to obtain a weighted composite image; Defect detection module 103: used for enhancing the weighted composite image to obtain an enhanced composite image; segmenting the enhanced composite image to obtain several new connected domains; and screening out bubble defect connected domains from all new connected domains by their areas.

[0064] A third aspect of the present invention is to provide an electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, a dry casing defect detection method based on an ultrasonic phased array is implemented.

[0065] A fourth aspect of the present invention is to provide a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, a dry casing defect detection method based on an ultrasonic phased array is implemented.

[0066] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, optical storage, etc.) containing computer-usable program code.

[0067] The present invention is described with reference to flowcharts and / or block diagrams of methods, systems, and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowcharts and / or block diagrams. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0068] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0069] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0070] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered by the scope of protection of the present invention.

Claims

1. A dry casing defect detection method based on ultrasonic phased array, characterized in that: include: Acquire a plane wave deflection angle sequence consisting of several plane wave deflection angles; obtain full matrix data corresponding to each deflection angle in the plane wave deflection angle sequence through an ultrasonic phased array detection system; and obtain the focusing delay of each transmitting array element at each deflection angle; Acquire a single plane wave image corresponding to each deflection angle in the deflection angle sequence; acquire an acoustic path from each pixel point to each transmitting array element and each receiving array element in the single plane wave image corresponding to each deflection angle, and obtain a total flight time from each pixel point to each transmitting array element and each receiving array element in the single plane wave image based on the acoustic path and the focusing delay of each transmitting array element; According to the total flight time and the full matrix data corresponding to the single plane wave imaging corresponding to each deflection angle; obtaining the superimposed signal intensity of each pixel point in the single plane wave imaging corresponding to each deflection angle; obtaining the coherence factor of the pixel point corresponding to each position according to the superimposed signal intensity of the pixel point at the same position in the single plane wave imaging corresponding to all deflection angles in the deflection angle sequence; adjusting the superimposed signal intensity of the pixel point at the same position in the single plane wave imaging corresponding to all deflection angles in the deflection angle sequence by the coherence factor to obtain a weighted composite image; enhancing the weighted composite image to obtain an enhanced composite image; The enhanced composite image is segmented to obtain several new connected domains; the bubble defect connected domains are screened out from all the new connected domains according to the area of the new connected domains.

2. The dry casing defect detection method based on ultrasonic phased array according to claim 1 is characterized in that: The acquiring of the focusing delay of each transmitting array element at each deflection angle includes: Where, Indicates the The transmission deflection angle of the transmitting array element, represents the speed of sound in the medium, Indicates the The focusing delay of each transmitting element, Indicates the The distance between the transmitting element and the center of the array.

3. The dry casing defect detection method based on ultrasonic phased array according to claim 1 is characterized in that: The method comprises: obtaining a single plane wave imaging corresponding to each deflection angle in the deflection angle sequence; obtaining an acoustic path from each pixel point to each transmitting array element and each receiving array element in the single plane wave imaging corresponding to each deflection angle, and obtaining a total flight time from each pixel point to each transmitting array element and each receiving array element in the single plane wave imaging based on the acoustic path and the focusing delay of each transmitting array element, comprising: The single plane wave imaging corresponding to each deflection angle in the deflection angle sequence is obtained by plane wave composite imaging algorithm; Where, Represents the coordinates of a pixel point in single plane wave imaging, Represents the transmitting array element The coordinates of Receiving array element coordinates of Represents the distance from each pixel to the transmitting array element in single plane wave imaging The sound distance between Represents the distance from each pixel to the receiving array element in single plane wave imaging The sound distance between Where, Represents the transmitting array element Focus delay, represents the longitudinal wave speed of sound, Represents the distance from each pixel to the transmitting array element in single plane wave imaging and receiving array elements total flight time.

4. The dry casing defect detection method based on ultrasonic phased array according to claim 1, characterized in that: The full matrix data corresponding to the single plane wave imaging corresponding to each deflection angle according to the total flight time; Obtain the superimposed signal intensity of each pixel in the single plane wave imaging corresponding to each deflection angle, including: Where, Represents the distance from each pixel to the transmitting array element in single plane wave imaging and receiving array elements Total flight time, Indicates Find the corresponding signal intensity in the full matrix data for the index; represents the total number of transmitting array elements, Represents the total number of receiving array elements, Represents the superimposed signal intensity of each pixel in the single plane wave imaging corresponding to each deflection angle.

5. The dry casing defect detection method based on ultrasonic phased array according to claim 1, characterized in that: Obtaining the coherence factor of the pixel corresponding to each position according to the superimposed signal intensity of the pixel at the same position in the single plane wave imaging corresponding to all deflection angles in the deflection angle sequence includes: Where, Indicates the first The position coordinates in single plane wave imaging corresponding to the deflection angle are: The superimposed signal strength of the corresponding pixel point, Indicates the number of all deflection angles in the deflection angle sequence, Indicates the absolute value symbol, The position coordinates are The coherence factor of the corresponding pixel.

6. The dry casing defect detection method based on ultrasonic phased array according to claim 1, characterized in that: The method further comprises adjusting the superimposed signal intensities of pixels at the same position in the single plane wave imaging corresponding to all deflection angles in the deflection angle sequence by the coherence factor to obtain a weighted composite image, including: Where, Indicates the first The position coordinates in single plane wave imaging corresponding to the deflection angle are: The superimposed signal strength of the corresponding pixel point, Indicates the number of all deflection angles in the deflection angle sequence, The position coordinates are The coherence factor of the corresponding pixel point, Indicates that the position coordinates in the fused image are The superimposed signal intensity of the corresponding pixel; A weighted composite image is formed by superimposing the signal intensities of the corresponding pixels at all positions in the fused image.

7. The dry casing defect detection method based on ultrasonic phased array according to claim 1, characterized in that: said enhancing the weighted composite image to obtain an enhanced composite image; Segment the enhanced composite image to obtain several new connected domains; From all new connected domains, filter out bubble defect connected domains by their area, including: The weighted composite image is enhanced by a linear enhancement algorithm to obtain an enhanced composite image. The enhanced composite image is segmented by semantic segmentation to obtain several connected domains. The neural network structure corresponding to semantic segmentation is a U-Net network, and the SE Block channel attention module is embedded in the skip connection of the U-Net network. A morphological closing operation is performed on several connected domains to obtain several new connected domains after processing; the areas of all the new connected domains are linearly normalized to obtain the normalized areas of the new connected domains; and the new connected domains whose normalized areas are smaller than a preset first reference area threshold and larger than a preset second reference area threshold in all the new connected domains are regarded as bubble defect connected domains.

8. A dry casing defect detection system based on ultrasonic phased array, characterized in that: include: Data acquisition module: used to obtain a plane wave deflection angle sequence consisting of several plane wave deflection angles; obtain the full matrix data corresponding to each deflection angle in the plane wave deflection angle sequence through the ultrasonic phased array detection system; obtain the focusing delay of each transmitting array element at each deflection angle; Image fusion module: used to obtain the single plane wave imaging corresponding to each deflection angle in the deflection angle sequence; obtain the acoustic path from each pixel point to each transmitting array element and each receiving array element in the single plane wave imaging corresponding to each deflection angle, and obtain the total flight time from each pixel point to each transmitting array element and each receiving array element in the single plane wave imaging based on the acoustic path and the focusing delay of each transmitting array element; According to the total flight time and the full matrix data corresponding to the single plane wave imaging corresponding to each deflection angle; obtaining the superimposed signal intensity of each pixel point in the single plane wave imaging corresponding to each deflection angle; obtaining the coherence factor of the pixel point corresponding to each position according to the superimposed signal intensity of the pixel point at the same position in the single plane wave imaging corresponding to all deflection angles in the deflection angle sequence; adjusting the superimposed signal intensity of the pixel point at the same position in the single plane wave imaging corresponding to all deflection angles in the deflection angle sequence by the coherence factor to obtain a weighted composite image; Defect detection module: used to enhance the weighted composite image to obtain an enhanced composite image; The enhanced composite image is segmented to obtain several new connected domains; the bubble defect connected domains are screened out from all the new connected domains according to the area of the new connected domains.

9. An electronic device, characterized in that: The invention comprises a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the dry casing defect detection method based on ultrasonic phased array according to any one of claims 1 to 7 is implemented.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the dry casing defect detection method based on ultrasonic phased array according to any one of claims 1 to 7 is implemented.

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