Residual stress determination method and system

Abstract

The present invention relates to the field of data processing, and in particular to a residual stress determination method and system. The method comprises the steps of: collecting an X-ray diffraction spectrum; recording any maximum point as a target maximum point, adjusting the X-ray diffraction spectrum to obtain an adjusted X-ray diffraction spectrum, calculating the left slope continuity and the right slope continuity of the target maximum point according to the adjusted X-ray diffraction spectrum; calculating the main peak degree of the target maximum point according to the left slope continuity and the right slope continuity; splitting the X-ray diffraction spectrum into several IMF components; calculating the main peak description degree of the IMF component according to the main peak degree; obtaining the denoised X-ray diffraction spectrum based on the main peak description degree; to realize residual stress detection. Accurate denoising is achieved by distinguishing noise peaks from diffraction peaks.

Description

Technical Field

[0001] The present invention relates to the field of data processing, and in particular to a residual stress determination method and system. Background Art

[0002] There are currently a variety of residual stress measurement methods, most of which will cause a certain degree of damage to the test piece when testing it, so these residual stress detection methods cannot be used in many situations. X-ray method residual stress detection will not damage the test piece when testing it, so the present invention uses X-ray method to perform residual stress detection.

[0003] When the X-ray method is used to detect residual stress of the part to be tested, X-rays are emitted onto the part to be tested. When the X-rays enter the part to be tested, diffraction will occur. The residual stress of the part to be tested is different, and the lattice distortion inside the material is different. The different lattice distortions cause X-ray diffraction, so the residual stress of the part to be tested can be inferred based on the diffraction spectrum generated by the X-rays in the part to be tested. In the process of collecting X-ray diffraction spectra, it is easy to be affected by noise caused by factors such as instrument vibration and electromagnetic interference. These noises will affect the accuracy of residual stress detection, so the collected X-ray diffraction spectra need to be denoised.

[0004] At present, the empirical mode decomposition (EMD) algorithm is often used to denoise the X-ray diffraction spectrum. This algorithm achieves denoising of the X-ray diffraction spectrum by decomposing the high-frequency components of the X-ray diffraction spectrum and removing them. However, the diffraction peak in the X-ray diffraction spectrum itself has a high frequency, and the diffraction peak information can be easily removed by frequency, thus affecting the subsequent residual stress inference analysis. Therefore, how to distinguish useful information from noise information and achieve accurate denoising becomes the research focus of the present invention.

[0005] In the 3rd issue of 2023 of the Journal of Analytical Chemistry, there is an article entitled "Research on X-ray Diffraction Spectrum Noise Removal Method Based on Empirical Mode Decomposition and t-test". In this article, the denoising of X-ray diffraction spectra is achieved by decomposing and removing the high-frequency components in the X-ray diffraction spectrum. This article does not take into account that some diffraction peaks themselves have a higher frequency, so it is easy to remove the diffraction peak information through this denoising method. Therefore, the method in this article cannot solve the problem in the present invention. Summary of the invention

[0006] In order to solve the problem of distinguishing useful information from noise information and achieving accurate denoising, the present invention provides a residual stress measurement method and system.

[0007] In a first aspect, the present invention provides a residual stress determination method, comprising the steps of:

[0008] Collecting X-ray diffraction spectrum of the object to be tested;

[0009] Obtain all extreme points and all peaks in the X-ray diffraction spectrum, record any maximum point as the target maximum point, connect the two minimum points of other peaks in the X-ray diffraction spectrum except the peak where the target maximum point is located to obtain an adjusted X-ray diffraction spectrum, obtain the first monotonic cutoff point on the left side of the target maximum point in the adjusted X-ray diffraction spectrum and record it as the left monotonic cutoff point, and use the cumulative sum of the sub-slope possibilities of all regions between the target maximum point and the left monotonic cutoff point as the left slope continuity of the target maximum point, wherein the sub-slope possibility is the product of the height difference between the two boundary points of the region and the degree of smoothness of the region; obtain the right slope continuity of the target maximum point; and use the cumulative sum of the left slope continuity and the right slope continuity of the target maximum point multiplied by the normalized value of the peak mark value as the main peak degree of the target maximum point;

[0010] The X-ray diffraction spectrum is split into several IMF components using the EMD algorithm; the corresponding points of each maximum point in the IMF component are obtained, the main peak degree of each maximum point is used as the weight of the corresponding point, and the heights of all corresponding points are weighted and summed to obtain the main peak description degree of the IMF component;

[0011] The IMF components are clustered into two categories based on the degree of main peak description, and the denoised X-ray diffraction spectrum is reconstructed using the IMF components in the category with a large mean of the main peak description degree, so as to realize residual stress detection.

[0012] The present invention determines whether the maximum point is useful information by analyzing the continuity of the slope of the maximum point, and then determines whether the IMF component contains useful information according to the situation that the IMF component contains different maximum point information, thereby excluding the IMF component containing noise information and improving the denoising accuracy; further, compared with the noise maximum value, the slope continuity of the maximum point of the diffraction peak is greater, so by analyzing the continuity of the slope of each maximum point to determine whether each maximum point contains useful information, the noise maximum point and the useful maximum point are distinguished, providing a basis for accurate denoising. Further, by connecting the minimum values ​​on both sides of the maximum value, the X-ray diffraction spectrum is smoothed to eliminate the interference of the noise peak, providing a basis for accurately obtaining the cutoff point of the peak where the maximum point is located. Further, when analyzing the continuity of the slope of the maximum point, the characteristics of the smoothness and height change of the slope are used to accurately calculate the situation that each area around the extreme point is a slope, and the accurate calculation of the slope continuity is achieved.

[0013] Preferably, the step of obtaining the first monotonic cutoff point on the left side of the target maximum point in the adjusted X-ray diffraction spectrum as the left monotonic cutoff point includes:

[0014] All extreme value points in the adjusted X-ray diffraction spectrum are obtained, and the first extreme value point on the left side of the target maximum value point is obtained from all extreme value points in the adjusted X-ray diffraction spectrum and recorded as the left monotonic cutoff point.

[0015] The present invention obtains the monotonic cutoff point by performing monotonicity analysis on the adjusted X-ray diffraction spectrum, thereby eliminating the interference of noise peaks and relatively accurately obtaining the cutoff position of the peak where the target maximum point is located.

[0016] Preferably, the method for obtaining the area includes:

[0017] Each peak from the target maximum point to the left monotonic cutoff point is regarded as a region;

[0018] The signal of the X-ray diffraction spectrum between the target maximum point and the nearest minimum point is regarded as a region.

[0019] The present invention divides the area between the target maximum point and the left monotonic cutoff point into multiple sub-areas using peaks, thereby providing a basis for subsequent accurate calculation of smoothness.

[0020] Preferably, the method for obtaining the degree of regional smoothness includes:

[0021] The reciprocal of the area enclosed by the line connecting the two boundary points of the region and the X-ray diffraction spectrum is taken as the degree of smoothness.

[0022] The present invention accurately and simply describes the smoothness of each region by introducing the line connecting the two boundary points of the region and the area enclosed by the X-ray diffraction spectrum, thereby providing a basis for accurate slope continuity analysis.

[0023] Preferably, the method for obtaining the peak value mark includes:

[0024] Get the right monotonic cutoff point, add the absolute value of the height difference between the left monotonic cutoff point and the right monotonic cutoff point to the anti-zero coefficient, and then take the reciprocal to obtain the peak mark value.

[0025] Preferably, obtaining the right slope continuity of the target maximum point includes:

[0026] The first monotonic cutoff point on the right side of the target maximum point in the adjusted X-ray diffraction spectrum is recorded as the right monotonic cutoff point, and the cumulative sum of the sub-slope possibilities of all areas between the target maximum point and the right monotonic cutoff point is taken as the right slope continuity of the target maximum point.

[0027] Preferably, obtaining corresponding points of each maximum point in the IMF component includes:

[0028] The point in the IMF component with the same horizontal coordinate as the maximum point is taken as the corresponding point of the maximum point in the IMF component.

[0029] Preferably, the step of connecting two minimum points of other peaks in the X-ray diffraction spectrum except the peak where the target maximum point is located to obtain an adjusted X-ray diffraction spectrum comprises:

[0030] In the X-ray diffraction spectrum, other peaks other than the peak where the target maximum point is located are obtained, adjacent extreme points are obtained on both sides of each other peak, and the signal obtained by connecting two adjacent extreme points of each other peak is used as the adjusted X-ray diffraction spectrum.

[0031] The present invention smoothes the X-ray diffraction spectrum by connecting the minimum points on both sides of the maximum point, thereby eliminating the interference of noise peaks and providing a basis for accurately obtaining the boundary of the peak where the maximum point is located.

[0032] Preferably, the step of obtaining all extreme points and all peaks in the X-ray diffraction spectrum includes:

[0033] All extreme value points in the X-ray diffraction spectrum are obtained, and the area between two adjacent minimum value points in the X-ray diffraction spectrum is regarded as a peak.

[0034] In a second aspect, a residual stress measuring system includes: a processor and a memory, wherein the memory stores computer program instructions, and when the computer program instructions are executed by the processor, the above-mentioned residual stress measuring method is implemented.

[0035] By adopting the above technical solution, the above residual stress determination method is generated into a computer program and stored in a memory so as to be loaded and executed by a processor, thereby manufacturing a terminal device based on the memory and the processor for easy use.

[0036] The present invention has the following technical effects:

[0037] The present invention determines whether the maximum point is useful information by analyzing the slope continuation of the maximum point, and then determines whether the IMF component contains useful information according to the situation that the IMF component contains different maximum point information, thereby excluding the IMF component containing noise information and improving the denoising accuracy;

[0038] Furthermore, compared with the noise maximum, the slope continuity of the maximum point of the diffraction peak is greater. Therefore, by analyzing the slope continuity of each maximum point, it is possible to judge whether each maximum point contains useful information, thereby distinguishing the noise maximum point from the useful maximum point, providing a basis for accurate denoising.

[0039] Furthermore, the X-ray diffraction spectrum is smoothed by connecting the minimum values ​​on both sides of the maximum value to eliminate the interference of noise peaks, thus providing a basis for accurately obtaining the cutoff point of the peak where the maximum value point is located.

[0040] Furthermore, when analyzing the continuity of the slope of the maximum point, the characteristics of the slope's smoothness and height variation are used to accurately calculate the slope of each area around the extreme point, thereby achieving accurate calculation of the continuity of the slope. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] By reading the detailed description below with reference to the accompanying drawings, the above and other purposes, features and advantages of the exemplary embodiments of the present invention will become readily understood. In the accompanying drawings, several embodiments of the present invention are shown in an exemplary and non-restrictive manner, and the same or corresponding reference numerals represent the same or corresponding parts.

[0042] Figure 1 is a flow chart of a residual stress determination method in an embodiment of the present invention;

[0043] Figure 2 A schematic diagram of an X-ray diffraction spectrum provided by an embodiment of the present invention;

[0044] Figure 3 An adjusted X-ray diffraction spectrum based on target maximum point 1 provided in an embodiment of the present invention;

[0045] Figure 4 An adjusted X-ray diffraction spectrum based on target maximum point 2 provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0046] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are 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 those skilled in the art without creative work are within the scope of protection of the present invention.

[0047] It should be understood that when the terms "first", "second", etc. are used in the claims, descriptions, and drawings of the present invention, they are only used to distinguish different objects, rather than to describe a specific order. The terms "include" and "comprise" used in the description and claims of the present invention indicate the presence of the described features, wholes, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components, and / or their collections.

[0048] The present invention discloses a residual stress determination method, referring to Figure 1 , comprising steps S1 to S4:

[0049] S1: Collect the X-ray diffraction spectrum of the object to be tested.

[0050] Specifically, an X-ray residual stress analyzer is used to collect an X-ray diffraction spectrum of the part to be tested.

[0051] S2: Obtain all extreme points and all peaks in the X-ray diffraction spectrum, record any maximum point as the target maximum point, connect the two minimum points of other peaks in the X-ray diffraction spectrum except the peak where the target maximum point is located to obtain an adjusted X-ray diffraction spectrum, obtain the first monotonic cutoff point on the left side of the target maximum point in the adjusted X-ray diffraction spectrum and record it as the left monotonic cutoff point, and use the cumulative sum of the sub-slope possibilities of all regions between the target maximum point and the left monotonic cutoff point as the left slope continuity of the target maximum point, wherein the sub-slope possibility is the product of the height difference between the two boundary points of the region and the degree of smoothness of the region; obtain the right slope continuity of the target maximum point; and use the cumulative sum of the left slope continuity and the right slope continuity of the target maximum point multiplied by the normalized value of the peak mark value as the main peak degree of the target maximum point.

[0052] It should be noted that the X-ray diffraction spectrum contains many diffraction peaks, and the diffraction peaks generally change sharply, so the frequency of the diffraction peaks is also high. Therefore, the frequency information cannot completely distinguish the noise information from the diffraction peak information. Figure 2 As shown in the schematic diagram of the X-ray diffraction spectrum, the diffraction peak is generally an independent peak, and the noise peak is generally only in a partial area of ​​the independent peak and does not have the characteristics of an independent peak. Therefore, the noise information and the diffraction peak information can be distinguished by analyzing the situation where each information in the X-ray diffraction spectrum has an independent peak.

[0053] S20: Obtain all extreme points and all peaks in the X-ray diffraction spectrum, record any maximum point as the target maximum point, connect the two minimum points of other peaks in the X-ray diffraction spectrum except the peak where the target maximum point is located to obtain an adjusted X-ray diffraction spectrum, obtain the first monotonic cutoff point on the left side of the target maximum point in the adjusted X-ray diffraction spectrum as the left monotonic cutoff point, and take the cumulative sum of the sub-slope possibilities of all areas between the target maximum point and the left monotonic cutoff point as the left slope continuity of the target maximum point.

[0054] It should be noted that an independent peak generally has a very long continuous slope, and the situation that each information in the X-ray diffraction spectrum has an independent peak can be judged by analyzing the situation that each information in the X-ray diffraction spectrum has a continuous slope.

[0055] S200: Obtain all extreme value points and all peaks in the X-ray diffraction spectrum, record any maximum value point as a target maximum value point, and connect the two minimum value points of other peaks in the X-ray diffraction spectrum except the peak where the target maximum value point is located to obtain an adjusted X-ray diffraction spectrum.

[0056] It should be noted that the continuation slope generally has the characteristics of monotonically decreasing, and the continuation slope can be analyzed by the continuation of the monotonically decreasing slope. When analyzing the continuation of the monotonically decreasing slope, the monotonically decreasing cutoff point must be obtained first. Figure 2 As shown in the figure, when there is no noise interference, the values ​​of other areas in the X-ray diffraction spectrum except the diffraction peak are relatively similar. Therefore, when there is no noise interference, the boundary position of the diffraction peak is also the monotonic cutoff position of the diffraction peak. In fact, there will be noise interference on the diffraction peak of the X-ray diffraction spectrum, and the monotonically decreasing cutoff position is not the boundary position of the diffraction peak. In order to prevent noise interference, all peaks on both sides need to be removed.

[0057] Preferably, as an example, all extreme points and all peaks in the X-ray diffraction spectrum are obtained, any maximum point is recorded as the target maximum point, and the two minimum points of other peaks in the X-ray diffraction spectrum except the peak where the target maximum point is located are connected to obtain the adjusted X-ray diffraction spectrum, including:

[0058] All extreme value points in the X-ray diffraction spectrum are obtained, and the area between two adjacent minimum value points in the X-ray diffraction spectrum is regarded as a peak.

[0059] Any maximum point is recorded as the target maximum point, and other peaks other than the peak where the target maximum point is located are obtained in the X-ray diffraction spectrum, and the two minimum points of other peaks are obtained. The signal obtained by connecting the two minimum points of other peaks is used as the adjusted X-ray diffraction spectrum. Figure 3 and Figure 4 The adjusted X-ray diffraction spectra are shown in Figure 3 The adjusted X-ray diffraction spectrum based on the target maximum point 1 is shown. Figure 4 The X-ray diffraction spectrum after adjustment based on the target maximum point 2 is shown.

[0060] It is understandable that if Figure 3 and Figure 4 As shown in FIG. 1 , by removing the peaks other than the peak where the target maximum point is located, the curve is smoothed, thereby effectively preventing the interference of noise on the monotonic analysis.

[0061] S201: Obtain the first monotonic cutoff point on the left side of the target maximum point in the adjusted X-ray diffraction spectrum and record it as the left monotonic cutoff point.

[0062] Preferably, as an example, obtaining the first monotonic cutoff point on the left side of the target maximum point in the adjusted X-ray diffraction spectrum is recorded as the left monotonic cutoff point, including:

[0063] All extreme value points in the adjusted X-ray diffraction spectrum are obtained, and the first extreme value point on the left side of the target maximum value point is obtained from all extreme value points in the adjusted X-ray diffraction spectrum and recorded as the left monotonic cutoff point.

[0064] S202: The cumulative sum of the sub-slope possibilities of all regions between the target maximum point and the left monotonic cutoff point is taken as the left slope continuity of the target maximum point.

[0065] It should be noted that the monotonic cutoff point obtained by removing the peak may not be accurate. The slope between the target maximum point and the left monotonic cutoff point may not necessarily be the slope of the peak where the target maximum point is located. Therefore, it is necessary to determine whether each area between the target maximum point and the left monotonic cutoff point belongs to the slope.

[0066] It should be further explained that when an area from the target maximum point to the left monotonic cutoff point belongs to a slope, the area should be relatively smooth and there should be height changes. Therefore, it can be judged based on this whether each area belongs to a slope.

[0067] Preferably, as an example, the cumulative sum of the sub-slope possibilities of all regions between the target maximum point and the left monotonic cutoff point is used as the left slope continuity of the target maximum point, including:

[0068] Each peak from the target maximum point to the left monotonic cutoff point is regarded as a region;

[0069] The signal of the X-ray diffraction spectrum between the target maximum point and the nearest minimum point is regarded as a region.

[0070] The reciprocal of the area enclosed by the line connecting the two boundary points of the region and the X-ray diffraction spectrum is taken as the degree of smoothness.

[0071] The product of the height difference between the two boundary points of the region and the degree of smoothness is taken as the sub-slope possibility.

[0072] The cumulative sum of the sub-slope possibilities of all areas between the target maximum point and the left monotone cutoff point is taken as the left slope continuity of the target maximum point.

[0073] It can be understood that if the area between the target maximum point and the left monotonic cutoff point is the slope of an independent peak, the area between the target maximum point and the left monotonic cutoff point should change relatively smoothly, and the smooth change is mainly manifested in the absence of large reverse fluctuations. If there is no large reverse fluctuation, the area enclosed by the line connecting the two boundary points of the region and the X-ray diffraction spectrum should be relatively small, so the smoothness can be reflected by the inverse of the area enclosed by the line connecting the two boundary points of the region and the X-ray diffraction spectrum. At the same time, when the area between the target maximum point and the left monotonic cutoff point is the slope of an independent peak, there will be height changes, so the height difference and smoothness of the two boundary points of the region are used to jointly reflect the possibility of the sub-slope of the region.

[0074] S21: Obtain the right slope continuity of the target maximum point.

[0075] Preferably, as an example, obtaining the right slope continuity of the target maximum point includes:

[0076] The first monotonic cutoff point on the right side of the target maximum point in the adjusted X-ray diffraction spectrum is recorded as the right monotonic cutoff point, and the cumulative sum of the sub-slope possibilities of all areas between the target maximum point and the right monotonic cutoff point is taken as the right slope continuity of the target maximum point.

[0077] S22: The cumulative sum of the left slope continuity and the right slope continuity of the target maximum point is multiplied by the normalized value of the peak mark value as the main peak degree of the target maximum point.

[0078] It should be noted that if Figure 4 As shown, there are some noise peaks, and the slope continuity on one side is larger. It is difficult to distinguish the noise peaks from the diffraction peaks by the slope continuity.

[0079] It should be further explained that the continuation height of the slope of the diffraction peak is similar, so the noise peak and the diffraction peak can be further distinguished based on this.

[0080] Preferably, as an example, the cumulative sum of the left slope continuity and the right slope continuity of the target maximum point multiplied by the normalized value of the peak mark value is used as the main peak degree of the target maximum point, including:

[0081] Get the right monotonic cutoff point, add the absolute value of the height difference between the left monotonic cutoff point and the right monotonic cutoff point to the anti-zero coefficient, and then take the reciprocal to obtain the peak mark value;

[0082] It can be understood that the absolute value of the height difference between the left monotonic cutoff point and the right monotonic cutoff point reflects the difference in the continued height of the slope of the peak where the target maximum point is located. The larger the value, the smaller the similarity of the continued height of the slope of the peak where the target maximum point is located, and therefore the peak where the target maximum point is located is more likely to be a noise peak.

[0083] The cumulative sum of the left slope continuity and the right slope continuity of the target maximum point multiplied by the normalized value of the peak mark value is used as the main peak degree of the target maximum point. This embodiment uses a hyperbolic tangent function for normalization, and other embodiments may use other methods for normalization, which is not specifically limited in this embodiment.

[0084] S3: Use the EMD algorithm to split the X-ray diffraction spectrum into several IMF components; obtain the corresponding points of each maximum point in the IMF component, use the main peak degree of each maximum point as the weight of the corresponding point, and perform weighted summation on the heights of all corresponding points to obtain the main peak description degree of the IMF component.

[0085] It should be noted that when the IMF component contains more main peak information of the X-ray diffraction spectrum, the amplitude of the IMF component at the main peak position should be larger, so it can be judged based on this that the IMF component contains useful information. This embodiment reflects the situation that the IMF component contains useful information through the main peak description degree.

[0086] Preferably, as an example, the corresponding points of each maximum point in the IMF component are obtained, the main peak degree of each maximum point is used as the weight of the corresponding point, and the heights of all corresponding points are weighted and summed to obtain the main peak description degree of the IMF component, including:

[0087] The point with the same horizontal coordinate as the maximum point in the IMF component is taken as the corresponding point of the maximum point in the IMF component, the main peak degree of each maximum point is taken as the weight of the corresponding point, and the heights of all corresponding points are weighted and summed to obtain the main peak description degree of the IMF component.

[0088] It can be understood that if the IMF component contains more main peak information, the amplitude of the IMF component at the main peak position is larger. Therefore, weighted summation of corresponding points in the IMF component using the main peak degree as the weight can reflect the situation in which the IMF component contains useful information, where the greater the main peak description degree, the more useful information is contained in the IMF component.

[0089] S4: The IMF components are clustered into two categories based on the degree of description of the main peak, and the denoised X-ray diffraction spectrum is reconstructed using the IMF components in the category with a large mean value of the main peak description degree to achieve residual stress detection.

[0090] S40: clustering the IMF components into two categories based on the degree of description of the main peak, and reconstructing the denoised X-ray diffraction spectrum using the IMF components in the category with a large mean value of the degree of description of the main peak.

[0091] Preferably, as an example, the IMF components are clustered into two categories based on the degree of description of the main peak, and the denoised X-ray diffraction spectrum is reconstructed using the IMF components in the category with a large mean value of the degree of description of the main peak, including:

[0092] According to the degree of description of the main peak, all IMF components are clustered into two categories, and the category with the largest mean value of the main peak description degree is obtained. The signal reconstructed from all IMF components in this category is used as the denoised X-ray diffraction spectrum.

[0093] It can be understood that useful information and useless information are separated by clustering, so that the denoised X-ray diffraction spectrum can be reconstructed using the useful information to eliminate the interference of noise signals.

[0094] It should be noted that using IMF to reconstruct a signal is an existing technology and will not be described in detail here.

[0095] S41: To achieve residual stress detection.

[0096] Preferably, as an example, to realize residual stress detection, the method includes:

[0097] The residual stress of the part to be tested is calculated by referring to the method for calculating residual stress based on X-ray diffraction spectrum in CN112729647A.

[0098] The embodiment of the present invention further discloses a residual stress measuring system, comprising a processor and a memory, wherein the memory stores computer program instructions, and when the computer program instructions are executed by the processor, a residual stress measuring method according to the present invention is implemented.

[0099] The above system also includes other components well known to those skilled in the art, such as a communication bus and a communication interface, and their configuration and functions are known in the art, so they will not be described in detail here.

[0100] In the present invention, the aforementioned memory may be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. For example, a computer-readable storage medium may be any suitable magnetic storage medium or magneto-optical storage medium, such as a resistive random access memory, a dynamic random access memory, a static random access memory, an enhanced dynamic random access memory, a high bandwidth memory, a hybrid storage cube, etc., or any other medium that can be used to store the required information and can be accessed by an application, a module, or both. Any such computer storage medium may be part of the device or accessible or connectable to the device.

[0101] Although this specification has shown and described a number of embodiments of the present invention, it will be apparent to those skilled in the art that such embodiments are provided by way of example only. Those skilled in the art will conceive of many modifications, changes and alternatives without departing from the ideas and spirit of the present invention. It should be understood that in the practice of the present invention, various alternatives to the embodiments of the present invention described herein may be employed.

[0102] The above are all preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A residual stress determination method, characterized in that: Includes steps: Collecting X-ray diffraction spectrum of the object to be tested; Obtain all extreme points and all peaks in the X-ray diffraction spectrum, record any maximum point as the target maximum point, connect the two minimum points of other peaks in the X-ray diffraction spectrum except the peak where the target maximum point is located to obtain an adjusted X-ray diffraction spectrum, obtain the first monotonic cutoff point on the left side of the target maximum point in the adjusted X-ray diffraction spectrum and record it as the left monotonic cutoff point, and use the cumulative sum of the sub-slope possibilities of all regions between the target maximum point and the left monotonic cutoff point as the left slope continuity of the target maximum point, where the sub-slope possibility is the product of the height difference between the two boundary points of the region and the degree of smoothness of the region; Obtain the right slope continuity of the target maximum point; multiply the accumulated sum of the left slope continuity and the right slope continuity of the target maximum point by the normalized value of the peak mark value as the main peak degree of the target maximum point; The method for obtaining the degree of regional smoothness includes: taking the reciprocal of the area enclosed by the line connecting the two boundary points of the region and the X-ray diffraction spectrum as the degree of regional smoothness; The method for obtaining the peak mark value comprises: obtaining the right monotonic cutoff point, adding the anti-zero coefficient to the absolute value of the height difference between the left monotonic cutoff point and the right monotonic cutoff point, and then taking the reciprocal to obtain the peak mark value; The X-ray diffraction spectrum is split into several IMF components using the EMD algorithm; the corresponding points of each maximum point in the IMF component are obtained, the main peak degree of each maximum point is used as the weight of the corresponding point, and the heights of all corresponding points are weighted and summed to obtain the main peak description degree of the IMF component; The IMF components are clustered into two categories based on the degree of main peak description, and the denoised X-ray diffraction spectrum is reconstructed using the IMF components in the category with a large mean of the main peak description degree, so as to realize residual stress detection.

2. The residual stress measuring method according to claim 1, characterized in that: The first monotonic cutoff point on the left side of the target maximum point in the adjusted X-ray diffraction spectrum is recorded as the left monotonic cutoff point, including: All extreme value points in the adjusted X-ray diffraction spectrum are obtained, and the first extreme value point on the left side of the target maximum value point is obtained from all extreme value points in the adjusted X-ray diffraction spectrum and recorded as the left monotonic cutoff point.

3. The residual stress measuring method according to claim 1, characterized in that: The method for obtaining the area includes: Each peak from the target maximum point to the left monotonic cutoff point is regarded as a region; The signal of the X-ray diffraction spectrum between the target maximum point and the nearest minimum point is regarded as a region.

4. The residual stress measuring method according to claim 1, characterized in that: The step of obtaining the right slope continuity of the target maximum point includes: The first monotonic cutoff point on the right side of the target maximum point in the adjusted X-ray diffraction spectrum is recorded as the right monotonic cutoff point, and the cumulative sum of the sub-slope possibilities of all areas between the target maximum point and the right monotonic cutoff point is taken as the right slope continuity of the target maximum point.

5. The residual stress measuring method according to claim 1, characterized in that: The obtaining of corresponding points of each maximum point in the IMF component includes: The point in the IMF component with the same horizontal coordinate as the maximum point is taken as the corresponding point of the maximum point in the IMF component.

6. The residual stress measuring method according to claim 1, characterized in that: The step of connecting two minimum points of other peaks in the X-ray diffraction spectrum except the peak where the target maximum point is located to obtain an adjusted X-ray diffraction spectrum comprises: In the X-ray diffraction spectrum, other peaks other than the peak where the target maximum point is located are obtained, adjacent extreme points are obtained on both sides of each other peak, and the signal obtained by connecting two adjacent extreme points of each other peak is used as the adjusted X-ray diffraction spectrum.

7. The residual stress measuring method according to claim 1, characterized in that: The obtaining of all extreme points and all peaks in the X-ray diffraction spectrum includes: All extreme value points in the X-ray diffraction spectrum are obtained, and the area between two adjacent minimum value points in the X-ray diffraction spectrum is regarded as a peak.

8. A residual stress measurement system, characterized in that: include: A processor and a memory, wherein the memory stores computer program instructions, and when the computer program instructions are executed by the processor, the residual stress determination method according to any one of claims 1 to 7 is implemented.

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