A method and system for constructing magnetic camera detection images to realize defect imaging detection

Abstract

The present invention discloses a method and system for constructing a magnetic camera detection image to realize defect imaging detection. The present invention comprises collecting detection signals of the surface of the detected element point by point and block by block with a horizontal spacing L and a vertical spacing D through an eddy current array sensor probe to obtain m×n groups of unit detection signal amplitudes a1, a2, .., a m×n A magnetic camera detection image is generated; based on the color difference of the magnetic camera detection image, it is judged whether the detected component has defects, and if there are defects, the location of the defects is determined based on the magnetic camera detection image. The defect image obtained by the present invention has a high original resolution, and can more accurately quantify defects based on the image processing method, effectively overcoming the imaging difference problem caused by the different angles of the magnetic sensor and the defect in the conventional scanning method, and has good applicability and can be widely promoted and applied.

Description

Technical Field

[0001] The present invention relates to the technical field of electromagnetic nondestructive testing of workpieces, and in particular to a method and system for constructing a magnetic camera detection image to realize defect imaging detection. Background Art

[0002] Eddy current nondestructive testing technology has become one of the effective means of defect detection in industrial metal materials with its advantages of high speed, high sensitivity, economy and pollution-free. The conventional eddy current coil array detection method is to form an array of wound coils, and perform C scanning based on the expansion of the detection signal to obtain imaging, which can identify defects in metal specimens. However, the conventional eddy current coil array scanning method will cause a deviation between the defect imaging and the actual position after the unit expansion function. At the same time, the different scanning directions of the magnetic sensors and the defect angles in the conventional scanning method will also cause imaging differences. The above-mentioned deficiencies of conventional eddy current coil array detection will make it difficult to accurately locate and quantify defects during the scanning imaging process. Summary of the invention

[0003] Technical problem to be solved by the present invention: In view of the above-mentioned problems in the prior art, a method and system for constructing a magnetic camera detection image to realize defect imaging detection are provided. The defect image obtained by the present invention has a high original resolution, and can be quantified more accurately based on the image processing method, effectively overcoming the imaging difference problem caused by the different angles of the magnetic sensor and the defect in the conventional scanning method, and has good applicability and can be widely promoted and applied.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0005] A method for constructing a magnetic camera detection image to realize defect imaging detection, characterized by comprising:

[0006] 1) The eddy current array sensor probe is driven by the three-axis platform to collect the detection signal of the surface of the detected component point by point and block by block with a horizontal spacing L and a vertical spacing D, and the m×n groups of unit detection signal amplitudes a1, a2, .., a m×n ;

[0007] 2) Based on m×n groups of unit detection signal amplitudes a1, a2, .., a m×n Generate magnetic camera detection images;

[0008] 3) Determine whether the inspected component has defects based on the color difference of the magnetic camera inspection image, and determine the location of the defect based on the magnetic camera inspection image if a defect exists.

[0009] Optionally, step 2) includes: dividing the m×n groups of unit detection signal amplitudes a1, a2, .., a m×nAn initial detection data matrix is ​​obtained by multiplying by a preset correction coefficient p; and a magnetic camera detection image is obtained by imaging based on the initial detection data matrix, and a single pixel resolution in the magnetic camera detection image directly corresponds to the spatial resolution of the sensor probe on the eddy current array sensor probe.

[0010] Optionally, before step 2), a step of calibrating the correction coefficient p is also included: a set of sample data a is collected from a defect-free area by using an eddy current array sensor probe, and the correction coefficient p is calculated according to the following formula:

[0011]

[0012] In the above formula, a0~a i They are respectively i sample data in a set of collected sample data a.

[0013] Optionally, in case of defects, step 3) further includes:

[0014] S1) interpolating the magnetic camera detection image according to the size of the eddy current array sensor probe to obtain an extended matrix image of the detection signal on the surface of the detected element, wherein each detection signal in the extended matrix image represents a pixel point, so that the resolution of a single pixel reaches a specified size, and imaging is performed based on the extended matrix image of the detection signal on the surface of the detected element to obtain super-resolution two-dimensional and pseudo-three-dimensional images of the defect;

[0015] S2) binarizing the super-resolution two-dimensional defect, segmenting the defect-free area from the defective area through binarization, and obtaining a quantitative detection result of the defect based on the pixel size of the defective area.

[0016] Optionally, the interpolation in step S1) refers to bicubic interpolation.

[0017] Optionally, in step S1), making the resolution of a single pixel reach a specified size refers to making the resolution of a single pixel reach 0.1 mm×0.1 mm.

[0018] Optionally, the binarization in step S2) includes first performing grayscale processing, and then using the im2bw function in MATLAB software to perform binarization based on the OTSU algorithm threshold.

[0019] In addition, the present invention also provides a system for constructing a magnetic camera detection image to realize defect imaging detection, including a microprocessor and a memory connected to each other, and the microprocessor is programmed or configured to execute the steps of the method for constructing a magnetic camera detection image to realize defect imaging detection.

[0020] In addition, the present invention also provides a magnetic camera defect imaging detection device, including an eddy current array sensor probe, a three-axis platform and a data processing device, wherein the eddy current array sensor probe is installed on the three-axis platform, and the eddy current array sensor probe and the data processing device are communicatively connected, and the data processing device is programmed or configured to execute the steps of the method of constructing a magnetic camera detection image to realize defect imaging detection.

[0021] In addition, the present invention also provides a computer-readable storage medium, in which a computer program is stored for being executed by a computer device to implement the method of constructing a magnetic camera detection image to realize defect imaging detection.

[0022] Compared with the prior art, the present invention mainly has the following advantages:

[0023] 1. The present invention proposes a method for constructing a magnetic camera to realize defect imaging and quantification. The magnetic camera is composed of a three-axis platform controlling the movement of an eddy current array sensor probe, collecting the signal amplitude on the surface of the inspected specimen in a point-by-point and block-by-block manner, splicing the unit detection signal as the pixel of the magnetic camera to realize defect imaging, and realizing defect positioning and quantification through imaging. Since the original resolution of the obtained defect image is higher, the defect can be more accurately quantified based on the image processing method, effectively overcoming the imaging difference problem caused by the different angles of the magnetic sensor and the defect in the conventional scanning method, and providing an effective method for the accurate positioning and quantification of surface defects of metal materials. It has good applicability and can be widely promoted and applied.

[0024] 2. The technical solution of the present invention realizes defect imaging and quantification by constructing a magnetic camera, simulating the function of a camera, and effectively overcoming the imaging difference problem caused by different angles of the sensor and the defect in the conventional scanning method. By collecting eddy current information on the surface of metal materials as imaging pixels, a super-resolution image of the defect is obtained based on the interpolation method, thereby improving the positioning and quantification accuracy of defects in the inspected samples. The present invention can also be applied to the quantification of defects on complex curved surfaces. The flexible characteristics of the array can cover most complex curved surface structures and reduce the interference of the surface structure of metal materials on the detection signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Schematic diagram of the basic flow of the method of the embodiment of the present invention.

[0026] Figure 2 This is an aluminum alloy sample with artificial defects in the embodiment of the present invention.

[0027] Figure 3 This is a magnetic camera detection image of a defect with a length of 11 mm in an embodiment of the present invention;

[0028] Figure 4This is a super-resolution two-dimensional image of a defect with a length of 11 mm in an embodiment of the present invention.

[0029] Figure 5 This is a super-resolution pseudo 3D image of a defect with a length of 11 mm in an embodiment of the present invention.

[0030] Figure 6 It is a defect binary image after image segmentation in an embodiment of the present invention. DETAILED DESCRIPTION

[0031] In order to better understand the present invention, the present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] Embodiment 1:

[0033] like Figure 1 As shown, the method of constructing a magnetic camera detection image to implement defect imaging detection in this embodiment includes:

[0034] 1) The eddy current array sensor probe is driven by the three-axis platform to collect the detection signal of the surface of the detected component point by point and block by block with a horizontal spacing L and a vertical spacing D, and the m×n groups of unit detection signal amplitudes a1, a2, .., a m×n ;

[0035] 2) Based on the m×n group of unit detection signal amplitudes a1, a2, .., a m×n Generate magnetic camera detection images;

[0036] 3) Determine whether the inspected component has defects based on the color difference of the magnetic camera inspection image, and determine the location of the defect based on the magnetic camera inspection image if a defect exists.

[0037] In this embodiment, the detected element is an aluminum alloy sample with a conductivity of 18.6MS / m, and a group of micro defects with an upper width of 0.1mm (lengths are 5mm, 7mm, 9mm, and 11mm, respectively), as shown in detail. Figure 2 As shown in the figure, the following will take the defect with a length of 11 mm as the specific detection object for further detailed description.

[0038] The setting basis of the lateral spacing L and the longitudinal spacing D in step 1) is completely determined by the actual size of the unit of the eddy current array, so as to achieve the purpose of making the defect recognition position after imaging completely consistent with the actual position.

[0039] In this embodiment, step 2) includes: m×nThe initial detection data matrix is ​​obtained by multiplying the preset correction coefficient p; the magnetic camera detection image is obtained by imaging based on the initial detection data matrix, and the single pixel resolution in the magnetic camera detection image directly corresponds to the spatial resolution of the sensor probe on the eddy current array sensor probe. As an optional implementation, the initial detection data matrix obtained in this embodiment is stored in a txt document.

[0040] The correction coefficient p is obtained by pre-calibration. In this embodiment, before step 2), a step of calibrating the correction coefficient p is also included: a set of sample data a is collected by selecting a defect-free area through the eddy current array sensor probe, denoted as a = [a0, a1, ..., a i ], and the correction coefficient p is calculated according to the following formula:

[0041]

[0042] In the above formula, a0~a i They are respectively i sample data in a set of collected sample data a.

[0043] Step 3) When judging whether the inspected component has defects based on the color difference of the image detected by the magnetic camera, in this embodiment, MATLAB software is used to read the matrix data in the txt document, and imaging can be directly performed based on the initial data. At this time, the resolution of a single pixel directly corresponds to the spatial resolution of the array unit. Imaging can identify defects on the sample (there are obvious color differences) and their specific locations, thereby achieving the goal of qualitative detection.

[0044] In this embodiment, the image obtained by directly imaging based on the initial data is as follows Figure 3 As shown, the imaging of the defect with a length of 11 mm is clear and intuitive, which verifies the feasibility of the method of this embodiment.

[0045] In addition, this embodiment also provides a system for constructing a magnetic camera detection image to implement defect imaging detection, including a microprocessor and a memory connected to each other, and the microprocessor is programmed or configured to execute the steps of the aforementioned method for constructing a magnetic camera detection image to implement defect imaging detection.

[0046] In addition, this embodiment also provides a magnetic camera defect imaging detection device, including an eddy current array sensor probe, a three-axis platform and a data processing device, wherein the eddy current array sensor probe is installed on the three-axis platform, and the eddy current array sensor probe and the data processing device are communicatively connected, and the data processing device is programmed or configured to execute the steps of the aforementioned method of constructing a magnetic camera detection image to realize defect imaging detection.

[0047] In addition, this embodiment further provides a computer-readable storage medium, in which a computer program is stored for being executed by a computer device to implement the aforementioned method of constructing a magnetic camera detection image to realize defect imaging detection.

[0048] Embodiment 2:

[0049] This embodiment is a further improvement of the first embodiment. On the basis of the qualitative detection in the reference document 1, the quantitative detection of defects is further realized. In this embodiment, in the case of defects, step 3) further includes:

[0050] S1) interpolating the magnetic camera detection image according to the size of the eddy current array sensor probe to obtain an extended matrix image of the detection signal on the surface of the detected element, wherein each detection signal in the extended matrix image represents a pixel point, so that the resolution of a single pixel reaches a specified size, and imaging is performed based on the extended matrix image of the detection signal on the surface of the detected element to obtain super-resolution two-dimensional and pseudo-three-dimensional images of the defect; the super-resolution two-dimensional image obtained in this embodiment is as shown in FIG. Figure 4 As shown, the super-resolution pseudo 3D image is Figure 5 As shown;

[0051] S2) Binarize the super-resolution two-dimensional image of the defect, separate the defect-free area from the defective area by binarization, and obtain the quantitative detection result of the defect (specifically the length of the defect in this embodiment) based on the pixel size of the defective area. The image obtained by binarization in this embodiment is as follows Figure 6 As shown, the length of the defect obtained based on the pixel size of the defective area is 10.9 mm, which is basically consistent with the actual length of the defect 11 mm, and the quantitative result is accurate.

[0052] The interpolation in step S1) can select a desired interpolation algorithm as needed. For example, as an optional implementation, the interpolation in step S1) in this embodiment refers to bicubic interpolation.

[0053] In step S1), making the resolution of a single pixel reach a specified size can be set as needed. For example, as an optional implementation, in step S1) of this embodiment, making the resolution of a single pixel reach a specified size means making the resolution of a single pixel reach 0.1mm×0.1mm.

[0054] The binarization performed in step S2) can select the desired binarization algorithm or binarization tool as needed. For example, as an optional implementation, the binarization performed in step S2) of this embodiment includes first performing grayscale processing, and then using the im2bw function in MATLAB software to perform binarization based on the OTSU algorithm threshold.

[0055] It should be noted that this embodiment and embodiment 1 are both based on aluminum alloy materials for detection, but the present invention can detect surface defects of various ferromagnetic materials, and the number and size of eddy current arrays can be flexibly arranged as needed.

[0056] In addition, this embodiment also provides a system for constructing a magnetic camera detection image to implement defect imaging detection, including a microprocessor and a memory connected to each other, and the microprocessor is programmed or configured to execute the steps of the aforementioned method for constructing a magnetic camera detection image to implement defect imaging detection.

[0057] In addition, this embodiment also provides a magnetic camera defect imaging detection device, including an eddy current array sensor probe, a three-axis platform and a data processing device, wherein the eddy current array sensor probe is installed on the three-axis platform, and the eddy current array sensor probe and the data processing device are communicatively connected, and the data processing device is programmed or configured to execute the steps of the aforementioned method of constructing a magnetic camera detection image to realize defect imaging detection.

[0058] In addition, this embodiment further provides a computer-readable storage medium, in which a computer program is stored for being executed by a computer device to implement the aforementioned method of constructing a magnetic camera detection image to realize defect imaging detection.

[0059] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present application may take the form of a computer program product implemented on one or more computer-readable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes. The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, may be implemented by computer program instructions. These computer program instructions may 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 functions in the process. Figure 1 A process or multiple processes and / or boxes Figure 1 These computer program instructions can also be stored in a computer-readable memory that can guide a computer or other programmable data processing device to work in a specific way, so that the instructions stored in the computer-readable memory produce a product including an instruction device, which implements the functions specified in the process. Figure 1 A process or multiple processes and / or boxes Figure 1 These computer program instructions can also be loaded onto a computer or other programmable data processing device, so that a series of operation steps are executed on the computer or other programmable device to produce a computer-implemented process, so that the instructions executed on the computer or other programmable device provide for implementing the process in the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0060] The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A method for constructing a magnetic camera detection image to realize defect imaging detection, characterized in that: include: 1) The eddy current array sensor probe is driven by the three-axis platform to collect the detection signal of the surface of the detected component point by point and block by block with a horizontal spacing L and a vertical spacing D. Group unit detection signal amplitude ; 2) Based on Group unit detection signal amplitude Generate magnetic camera detection images; 3) judging whether the inspected component has defects based on the color difference of the magnetic camera inspection image, and determining the location of the defect based on the magnetic camera inspection image if a defect exists; Step 2) includes: Group unit detection signal amplitude Multiplying by a preset correction coefficient p to obtain an initial detection data matrix; performing imaging based on the initial detection data matrix to obtain a magnetic camera detection image, wherein a single pixel resolution in the magnetic camera detection image directly corresponds to a spatial resolution of a sensor probe on an eddy current array sensor probe; Step 2) also includes the step of calibrating the correction coefficient p: select a defect-free area through the eddy current array sensor probe to collect a set of sample data , and the correction coefficient p is calculated according to the following formula: ， In the above formula, ~ A set of sample data collected In i Sample data; Step 3) also includes, in the event of defects: S1) interpolating the magnetic camera detection image according to the size of the eddy current array sensor probe to obtain an extended matrix image of the detection signal on the surface of the detected component, wherein each detection signal in the extended matrix image represents a pixel point, so that the resolution of a single pixel reaches a specified size, and imaging is performed based on the extended matrix image of the detection signal on the surface of the detected component to obtain super-resolution two-dimensional and pseudo-three-dimensional images of the defect; S2) Binarizing the super-resolution two-dimensional defect, segmenting the defect-free area from the defective area through binarization, and obtaining a quantitative detection result of the defect based on the pixel size of the defective area.

2. The method for constructing a magnetic camera detection image to realize defect imaging detection according to claim 1, characterized in that: The interpolation in step S1) refers to bicubic interpolation.

3. The method for constructing a magnetic camera detection image to realize defect imaging detection according to claim 1, characterized in that: In step S1), making the resolution of a single pixel reach a specified size means making the resolution of a single pixel reach 0.1 mm×0.1 mm.

4. The method for constructing a magnetic camera detection image to realize defect imaging detection according to claim 1, characterized in that: The binarization in step S2) includes first performing grayscale processing, and then using the im2bw function in MATLAB software to perform binarization based on the OTSU algorithm threshold.

5. A system for constructing a magnetic camera detection image to realize defect imaging detection, comprising a microprocessor and a memory connected to each other, characterized in that: The microprocessor is programmed or configured to execute the steps of the method for constructing a magnetic camera detection image to realize defect imaging detection as described in any one of claims 1 to 4.

6. A magnetic camera defect imaging detection device, comprising an eddy current array sensor probe, a three-axis platform and a data processing device, wherein the eddy current array sensor probe is mounted on the three-axis platform, and the eddy current array sensor probe and the data processing device are both communicatively connected, characterized in that: The data processing device is programmed or configured to execute the steps of the method for constructing a magnetic camera detection image to implement defect imaging detection as recited in any one of claims 1 to 4.

7. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program for being executed by a computer device to implement the method of constructing a magnetic camera detection image to realize defect imaging detection as described in any one of claims 1 to 4.

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