Method for automatically detecting blockage of cooling plate through X rays

Abstract

The invention relates to the technical field of detection, in particular to a method for automatically detecting blockage of a cooling plate through X-rays, which comprises the following steps: inputting an X-ray image, and extracting a pipeline wall contour area and a flow channel contour area in the image; eliminating a pipeline wall interference area based on the pipeline wall contour area to obtain a pure pipeline wall contour area; fusing the pure pipeline wall contour area and the flow channel contour area to obtain a non-blocking area, and calculating a pipeline group area and a blocking area based on the non-blocking area; according to the method, the position of the pipeline can be automatically positioned, frame selection of the ROI area is not needed, CNC programming steps are simplified, the method is not affected by the width of the flow channel of the pipeline, blockage can be accurately recognized, the defect can be accurately positioned even if part of interference exists, and the problems that the position of the pipeline is uncertain through manual observation of the X-ray image, and the detection accuracy is high are solved. The method is easy to be influenced by the width of a pipeline flow channel, and pipeline blockage identification is inaccurate.

Description

Technical Field

[0001] The invention relates to the field of detection technology, and in particular to a method for automatically detecting blockage of a cooling plate by X-ray. Background Art

[0002] As a heat dissipation device for new energy vehicle battery packs, the battery cooling plate is a key component of the vehicle thermal management system. The main function of the battery cooling plate is to ensure that the battery remains within a suitable temperature range during operation, thereby improving battery performance, extending service life and ensuring safety.

[0003] The cooling plate usually has many small pipes welded on the surface, which are filled with coolant to circulate the coolant to dissipate heat. Since the pipes are welded and very small, the flow channel may be blocked during the welding process.

[0004] Currently, most methods for detecting pipeline blockage are to manually observe X-ray images and then determine whether they are qualified. However, the position of the pipeline in the X-ray image is uncertain and easily affected by the width of the pipeline flow channel, making it inaccurate to identify pipeline blockage. Summary of the invention

[0005] The purpose of the present invention is to provide a method for automatically detecting cooling plate blockage by X-rays, aiming to solve the problem that the position of the pipeline in manual observation of X-ray images is uncertain, easily affected by the width of the pipeline flow channel, and the identification of pipeline blockage is inaccurate.

[0006] To achieve the above object, the present invention provides a method for automatically detecting cooling plate blockage using X-rays, comprising the following steps:

[0007] Input an X-ray image, and extract a pipe wall contour area and a flow channel contour area in the image;

[0008] Eliminate the pipeline wall interference area based on the pipeline wall contour area to obtain a pure pipeline wall contour area;

[0009] Merging the pure pipe wall contour area and the flow channel contour area to obtain a non-blocked area, and calculating the pipe group area and the blocked area based on the non-blocked area;

[0010] The interference area in the blocked area is eliminated to obtain a pure blocked area.

[0011] The specific method of extracting the pipe wall contour area and the flow channel contour area in the input X-ray image is as follows:

[0012] Traverse each pixel of the input X-ray image and calculate the standard deviation and mean in the pixel area around it;

[0013] The pipe wall pixel points and the flow channel pixel points are extracted based on the standard deviation and the mean value, and the pipe wall contour area and the flow channel contour area are obtained by finding the contour.

[0014] The specific method of excluding the pipeline wall interference area based on the pipeline wall contour area to obtain the pure pipeline wall contour area is as follows:

[0015] Calculate the circumscribed rectangle of the pipeline wall contour area to obtain the width, height, area, upper left point horizontal coordinate and upper right point horizontal coordinate of the circumscribed rectangle;

[0016] Based on the width, height, area, upper left point horizontal coordinate and upper right point horizontal coordinate of the circumscribed rectangle, the interference area is eliminated to obtain a pure pipeline wall contour area.

[0017] The specific method of fusing the pure pipe wall contour area and the flow channel contour area to obtain a non-blocked area, and calculating the pipe group area and the blocked area based on the non-blocked area is as follows:

[0018] The pure pipe wall contour area and the flow channel contour area are merged, and morphological expansion and corrosion operations are performed to find the contour again and obtain a non-blocked area;

[0019] Calculate the circumscribed rectangle based on the non-blocked area to obtain the pipeline group area;

[0020] The blocked area is obtained by subtracting the pipeline group area from the non-blocked area.

[0021] The specific method of removing the interference area in the blocked area to obtain a pure blocked area is as follows:

[0022] The circumscribed rectangle of the blocked area is calculated to obtain the width and height of the circumscribed rectangle, and the interference area is eliminated by the width and height of the circumscribed rectangle to obtain a pure blocked area.

[0023] The present invention discloses an X-ray automatic detection method for cooling plate blockage, which comprises the following steps: inputting an X-ray image, extracting a pipe wall contour area and a flow channel contour area in the image; excluding a pipe wall interference area based on the pipe wall contour area to obtain a pure pipe wall contour area; fusing the pure pipe wall contour area and the flow channel contour area to obtain a non-blocked area, and calculating a pipe group area and a blocked area based on the non-blocked area; eliminating the interference area in the blocked area to obtain a pure blocked area. The method can automatically locate the pipe position without selecting an ROI area, thus simplifying the steps of CNC programming, being unaffected by the width of the pipe flow channel, being able to accurately identify blockages, and being able to accurately locate defects even with partial interference, thus solving the problem that the position of the pipe in manually observed X-ray images is uncertain, being easily affected by the width of the pipe flow channel, and being unable to accurately identify pipe blockages. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. 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 creative work.

[0025] Figure 1 is a schematic diagram for determining the blocked area.

[0026] Figure 2 The present invention provides a flowchart of a method for automatically detecting cooling plate blockage using X-rays.

[0027] Figure 3 is the original image of the pipeline group area.

[0028] Figure 4 This is a rendering of the pipe wall contour area.

[0029] Figure 5 This is the effect diagram of the flow channel contour area.

[0030] Figure 6 The effect of non-blocked area.

[0031] Figure 7 This is the effect diagram of the blocked area.

[0032] Figure 8 The present invention provides a flow chart of a method for automatically detecting cooling plate blockage using X-rays.

[0033] Fig. 9 The invention is a flowchart of a specific method of inputting an X-ray image and extracting a pipe wall contour area and a flow channel contour area in the image.

[0034] Fig.10 The present invention is a flowchart of a specific method for excluding the pipeline wall interference area based on the pipeline wall contour area to obtain a pure pipeline wall contour area.

[0035] Fig.11 It is a flowchart of a specific method of fusing the pure pipe wall contour area and the flow channel contour area to obtain a non-blocked area, and calculating the pipe group area and the blocked area based on the non-blocked area. DETAILED DESCRIPTION

[0036] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0037] See also Figures 1 to 11 The present invention provides a method for automatically detecting blockage of a cooling plate by X-ray, comprising the following steps:

[0038] S1 inputs an X-ray image and extracts a pipe wall contour area and a flow channel contour area in the image;

[0039] Specific method:

[0040] S11 traverses each pixel of the input X-ray image and calculates the standard deviation and the mean in the surrounding pixel area;

[0041] In the embodiment of the present invention, the pipeline in the X-ray image usually has the following characteristics: ① The pipeline wall is a continuous straight line in the same direction; ② The grayscale value of the pipeline wall is lower than the surrounding background in the local area; ③ The grayscale value of the flow channel is higher than the surrounding background in the local area; ④ The blocked area usually has no pipeline wall, and multiple flow channels are connected together; ⑤ The grayscale value of the blocked area is lower than the surrounding grayscale value.

[0042] This step is to segment the pipe wall from the X-ray input X-ray image, using the judgment conditions of local standard deviation and mean. Traverse each pixel point of the input X-ray image, and calculate the standard deviation and mean in the m*n pixel area around it.

[0043] Calculate the mean μ in the local window of each pixel x，y , as shown in the following formula:

[0044]

[0045] Calculate the standard deviation σ within the local window of each pixel x，y , for each pixel I(x, y) in the image, the window size is m*n, as shown in the following formula:

[0046]

[0047] S12 extracts the pipe wall pixel points and the flow channel pixel points based on the standard deviation and the mean value, and obtains the pipe wall contour area and the flow channel contour area by finding the contour.

[0048] In the embodiment of the present invention, the pipeline wall pixel point G1(x, y) is extracted by using the two conditions of standard deviation and average gray value. x，yis the gray value of the current point, thresh1 is 0.2, thresh2 is 5, these two values ​​are empirical values. The pixel point G1(x, y) on the pipe wall that satisfies both conditions is as shown in the following formula:

[0049] G1(x, y)=(σ x，y >thresh1)∧(g x,y -μ x，y <thresh2)

[0050] In the same way, the pixel point G2(x, y) of the flow channel is extracted. x，y is the gray value of the current point, thresh3 is 0.2, and thresh4 is 6. These two values ​​are empirical values. The value that satisfies both conditions is the target value G2(x, y), as shown in the following formula:

[0051] G2(x,y)=(σ x，y >thresh3)∧(g x,y +μ x,y <thresh4)

[0052] The pipeline wall contour area C(i) is obtained by finding the contour of G1(x, y) and G2(x, y) (the effect is as follows Figure 4 As shown), and the flow channel contour area O(j) (the effect is as Figure 5 As shown in the figure, i represents the pipe wall number and j represents the flow channel number.

[0053] S2. excluding the pipeline wall interference area based on the pipeline wall contour area to obtain a pure pipeline wall contour area;

[0054] Specific method:

[0055] S21 calculates the circumscribed rectangle of the pipeline wall contour area to obtain the width, height, area, upper left point horizontal coordinate and upper right point horizontal coordinate of the circumscribed rectangle;

[0056] In the embodiment of the present invention, the circumscribed rectangles of the contour areas C(i) are calculated respectively (the pipe wall is usually a straight line, and its contour can be equivalent to a circumscribed rectangle), and then the width Rw(i), height Rh(i), area Rs(i), upper left point horizontal coordinate Rlx(i), and upper right point horizontal coordinate Rrx(i) of each circumscribed rectangle can be obtained (i represents the sequence number of the rectangle).

[0057] S22 eliminates interference areas based on the width, height, area, upper left point horizontal coordinate and upper right point horizontal coordinate of the circumscribed rectangle to obtain a pure pipeline wall contour area.

[0058] In the embodiment of the present invention, the interference area is then eliminated to obtain the real pipe wall contour area C1(i), which is eliminated by the following conditions, as shown in the following formula:

[0059] C1(i)=(R w (i)<15)∧(Rh(i)>10)∧(Rs(i)>200)

[0060] S3: fusing the pure pipe wall contour area and the flow channel contour area to obtain a non-blocked area, and calculating a pipe group area and a blocked area based on the non-blocked area;

[0061] Specific method:

[0062] S31: merging the pure pipe wall contour area and the flow channel contour area, and performing morphological expansion and corrosion operations to find the contour again and obtain a non-blocked area;

[0063] In the embodiment of the present invention, the regions of C1(i) ​​and O(j) are merged, and the merged regions are subjected to morphological dilation and corrosion operations, and then the contour of the new regions is re-finded. At this time, the non-blocked region C2(n) can be obtained (the effect is as follows Figure 6 shown).

[0064] S32 calculates a circumscribed rectangle based on the non-blocked area to obtain a pipeline group area;

[0065] In the embodiment of the present invention, the circumscribed rectangle C3(n) is calculated for C2(n), and C3(n) is the area of ​​the pipeline group.

[0066] S33: Subtract the pipeline group area from the non-blocked area to obtain the blocked area.

[0067] In the embodiment of the present invention, the blocked area C4(i) is calculated by subtracting the pipeline group area from the non-blocked area (the effect is as follows Figure 7 As shown in the following formula:

[0068] C4(i)=C3(n)-C2(n)

[0069] S4 removes the interference area in the blocked area to obtain a pure blocked area.

[0070] In the embodiment of the present invention, the average width w of the pipeline flow channel is calculated based on Rlx(i) and Rrx(i), and the middle three sets of coordinates are taken for calculation, where n = the number of circumscribed rectangles, as shown in the following formula:

[0071]

[0072] Calculate the bounding rectangle of C4(i) respectively, and then get the width C4w(i) and height C4h(i) of each bounding rectangle, where i represents the sequence number of the rectangle. Exclude the interference area by width and height, and the exclusion condition is as shown in the following formula:

[0073] C5(i)=(C4w(i)>w*0.8)∧(C4h(i)>3)

[0074] What is disclosed above is only a preferred embodiment of the method for automatically detecting cooling plate blockage by X-rays of the present invention. Of course, it cannot be used to limit the scope of rights of the present invention. Ordinary technicians in this field can understand that all or part of the processes of the above embodiments and equivalent changes made according to the claims of the present invention still fall within the scope of the invention.

Claims

1. A method for automatically detecting cooling plate blockage using X-rays, characterized in that: The following steps are involved: Input an X-ray image, and extract a pipe wall contour area and a flow channel contour area in the image; Eliminate the pipeline wall interference area based on the pipeline wall contour area to obtain a pure pipeline wall contour area; Merging the pure pipe wall contour area and the flow channel contour area to obtain a non-blocked area, and calculating the pipe group area and the blocked area based on the non-blocked area; The interference area in the blocked area is eliminated to obtain a pure blocked area.

2. The method for automatically detecting cooling plate blockage by X-ray according to claim 1, characterized in that; The specific method of extracting the pipe wall contour area and the flow channel contour area in the input X-ray image is as follows: Traverse each pixel of the input X-ray image and calculate the standard deviation and mean in the pixel area around it; The pipe wall pixel points and the flow channel pixel points are extracted based on the standard deviation and the mean value, and the pipe wall contour area and the flow channel contour area are obtained by finding the contour.

3. The method for automatically detecting cooling plate blockage by X-ray according to claim 1, It is characterized by: The specific method of excluding the pipeline wall interference area based on the pipeline wall contour area to obtain the pure pipeline wall contour area is: Calculate the circumscribed rectangle of the pipeline wall contour area to obtain the width, height, area, upper left point horizontal coordinate and upper right point horizontal coordinate of the circumscribed rectangle; Based on the width, height, area, upper left point horizontal coordinate and upper right point horizontal coordinate of the circumscribed rectangle, the interference area is eliminated to obtain a pure pipeline wall contour area.

4. The method for automatically detecting blockage of a cooling plate by X-ray according to claim 1, characterized in that ； The specific method of fusing the pure pipeline wall contour area and the flow channel contour area to obtain a non-blocked area, and calculating the pipeline group area and the blocked area based on the non-blocked area is as follows: The pure pipe wall contour area and the flow channel contour area are merged, and morphological expansion and corrosion operations are performed to find the contour again and obtain a non-blocked area; Calculate the circumscribed rectangle based on the non-blocked area to obtain the pipeline group area; The blocked area is obtained by subtracting the pipeline group area from the non-blocked area.

5. The method for automatically detecting cooling plate blockage by X-ray according to claim 1, It is characterized by: The specific method of removing the interference area in the blocked area to obtain a pure blocked area is: The circumscribed rectangle of the blocked area is calculated to obtain the width and height of the circumscribed rectangle, and the interference area is eliminated by the width and height of the circumscribed rectangle to obtain a pure blocked area.

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