Flaw detection method and system for vacuum isothermal forging raw materials

Abstract

The invention relates to the technical field of intelligent manufacturing, and provides a flaw detection method and system for a vacuum isothermal forging raw material, and the method comprises the steps: filling a detection groove with a preset amount of water, completely immersing the raw material in the water, and obtaining an optimal distance between an ultrasonic probe and the raw material according to a preset distance calculation strategy, the ultrasonic probes are arranged according to the optimal spacing; controlling the radial rotation of the raw material and the axial movement of the ultrasonic probe while transmitting ultrasonic waves to the raw material, imaging through a reflected wave signal of the ultrasonic waves to obtain an ultrasonic image, and segmenting the ultrasonic image to obtain a target image; and according to the raw material identifier, calling a raw material drawing associated with the identifier, distinguishing raw material types through the raw material drawing, according to different raw material types, adopting different flaw detection strategies for the target image to obtain the number of defect pixels, and according to the number of defect pixels, calculating the availability rate of the raw material. According to the invention, the vacuum isothermal forging raw material can be subjected to rapid and reliable nondestructive flaw detection.

Description

Technical Field

[0001] The present application belongs to the field of intelligent manufacturing technology, and specifically relates to a flaw detection method and system for vacuum isothermal forging raw materials. Background Art

[0002] Vacuum isothermal forging is a process that uses a vacuum environment to heat the die to the same temperature as the forging, and forms complex precision forgings at a lower deformation rate and fewer forging times under constant temperature conditions.

[0003] The raw materials for vacuum isothermal forging (for example, high temperature alloy bars) are also processed by rolling and other processes, and inevitably there will be defects such as cracks, pores, looseness, slag inclusions, etc. These defects will bring difficulties to the vacuum isothermal forging process and even cause the forgings to be scrapped. Therefore, before the vacuum isothermal forging process, the raw materials must be inspected for defects and the defective raw materials must be picked out to avoid greater losses.

[0004] At present, macroscopic inspection mainly relies on visual inspection to see if there are cracks, scratches, etc. on the bars, but this is far from guaranteeing the quality of the raw materials used; while microscopic inspection mainly uses ultrasonic testing. The principle is that when ultrasonic waves pass through different media, their propagation wavelength and speed will change, and reflected waves will be generated on the interface, that is, defective raw materials can be detected through abnormal reflected waves.

[0005] However, it has been found in practice that the reflected wave signal of ultrasonic testing is relatively weak, resulting in low resolution of ultrasonic imaging, which in turn makes it difficult to accurately and quickly identify raw material defects. Summary of the invention

[0006] The embodiments of the present application provide a method and system for flaw detection of vacuum isothermal forging raw materials to solve the above-mentioned technical problems in the prior art.

[0007] A first aspect of an embodiment of the present application provides a method for flaw detection of a vacuum isothermal forging raw material, comprising: Before vacuum isothermal forging, a predetermined amount of water is filled into the test tank, the raw material is grabbed by a manipulator and completely immersed in water, the optimal distance between the ultrasonic probe and the raw material is obtained according to the preset distance calculation strategy, and the ultrasonic probe is arranged according to the optimal distance; The manipulator is controlled to drive the raw material to rotate radially, and the ultrasonic probe moves axially while emitting ultrasonic waves to the raw material. The ultrasonic reflected wave signal is used to obtain an ultrasonic image, and the ultrasonic image is segmented to obtain a target image. According to the raw material identification, the raw material drawings associated with the identification are retrieved, and the raw material types are distinguished by the raw material drawings. According to different raw material types, different flaw detection strategies are adopted for the target image to obtain the number of defective pixels. According to the number of defective pixels, the availability of the raw materials is calculated.

[0008] In some embodiments, before performing vacuum isothermal forging, a predetermined amount of water is filled into the detection tank, a raw material is grabbed by a manipulator, and the raw material is completely immersed in water, an optimal distance between the ultrasonic probe and the raw material is obtained according to a preset distance calculation strategy, and the ultrasonic probe is arranged according to the optimal distance, wherein the optimal distance between the ultrasonic probe and the raw material is obtained according to the preset distance calculation strategy, including the following contents: According to the preset discrete step distance, the preset distance interval is discretized to obtain multiple different interval values; The cyclic calculation method is used to calculate the voltage amplitude of the ultrasonic reflected wave corresponding to different spacing values ​​through the preset ultrasonic measurement model; The ultrasonic reflected wave voltage amplitudes corresponding to different spacing values ​​are fitted to obtain a discrete reflected wave voltage amplitude variation curve; The maximum reflected wave voltage amplitude in the curve is calculated, and the spacing value corresponding to the maximum echo voltage amplitude is used as the optimal spacing between the ultrasonic probe and the raw material.

[0009] In some embodiments, the cyclic calculation method is used to calculate the ultrasonic reflected wave voltage amplitudes corresponding to different spacing values ​​through a preset ultrasonic measurement model, wherein the preset ultrasonic measurement model includes the following contents: By superimposing multiple single Gaussian sound beams, the vibration velocity of any particle in the sound field radiated by the ultrasonic probe is calculated; Integrate the vibration velocity of the particle on the surface of the ultrasonic probe to obtain the receiving impedance of the probe surface; According to the receiving impedance and output impedance of the probe surface, the acoustic elastic propagation function describing the law between the probe transmitting and receiving reflected waves is obtained; According to the acoustic elastic propagation function and the pulse excitation system function, the ultrasonic measurement model is obtained.

[0010] In some embodiments, the acoustic elastic propagation function describing the law between the probe transmitting and receiving reflected waves is obtained according to the probe surface receiving impedance and output impedance, wherein the acoustic elastic propagation function is expressed by the following formula: In the above formula, represents the acoustic elastic propagation function, Indicates the receiving impedance of the probe surface. It indicates the output impedance of the probe surface. When a circular plane probe is used for detection, the output impedance of the probe surface is considered to be a constant.

[0011] In some embodiments, the ultrasonic measurement model is obtained according to the acoustic elastic propagation function and the pulse excitation system function, wherein the pulse excitation system function is determined according to the equivalent voltage, pulse electrical impedance, probe electrical impedance and sensitivity during ultrasonic detection, or is obtained by an experimental test method; The ultrasonic measurement model is expressed by the following formula: In the above formula, represents the frequency domain characteristics of the reflected wave voltage, represents the impulse excitation system function, represents the acoustic elastic propagation function.

[0012] In some embodiments, the control manipulator drives the raw material to rotate radially, and the ultrasonic probe moves axially while emitting ultrasonic waves to the raw material, imaging is performed through the reflected wave signal of the ultrasonic wave to obtain an ultrasonic image, and the ultrasonic image is segmented to obtain a target image, wherein the ultrasonic image is segmented to obtain the target image, including the following contents: A set of continuous values ​​is set for the direction parameter of the Gabor filter, a set of Gabor filters with different directions is selected to filter the ultrasound image, and the image is fused by the maximum value of the pixel grayscale to obtain a first intermediate image; The first intermediate image is filtered by a multi-center frequency Gabor filter, and is fused by a mean fusion method to obtain a second intermediate image; The level set method is used to calculate the edges in the second intermediate image, and the target image is obtained by segmentation based on the edges.

[0013] In some embodiments, it also includes: Convert the color information of the target image into amplitude information, including the following: The (R, G, B) value of each pixel in the target image The (R, G, B) value of each pixel in the color band Perform a one-by-one comparison; When the (R, G, B) value at the (x, y) coordinate position of the target image is closest to the (R, G, B) value of the i-th pixel of the color band, the amplitude at the (x, y) coordinate position of the target image is the amplitude corresponding to the i-th pixel of the color band.

[0014] In some embodiments, according to the raw material identification, the raw material drawing associated with the identification is retrieved, the raw material type is distinguished by the raw material drawing, and different flaw detection strategies are adopted for the target image according to different raw material types to obtain the number of defective pixels, and the availability of the raw material is calculated according to the number of defective pixels, wherein: the raw material type includes those without structural features and those with structural features.

[0015] In some embodiments, the method of adopting different flaw detection strategies for the target image to obtain the number of defective pixels and calculating the availability of the raw material according to the number of defective pixels specifically includes the following contents: When there are no structural features, the target image is identified by setting the defect amplitude threshold, and the number of pixels within the amplitude threshold is counted as the number of defective pixels. The raw material availability is calculated based on the number of defective pixels and the number of overall pixels. When there are structural features, check the complex structural features and key areas and non-key areas in the target image; then set the width information of the structural features to zero the amplitude within the structural features; finally, count the number of pixels of defects in the key areas and non-key areas respectively, and calculate the availability of the raw materials based on the number of defective pixels and the overall number of pixels.

[0016] As can be seen from the above, the embodiment of the present application adopts a water immersion ultrasonic flaw detection method for vacuum isothermal forging raw materials, that is, the ultrasonic probe and the raw materials are immersed in water, water is used as a coupling agent, and ultrasonic waves are emitted to the raw materials through the water. The influence of the acoustic properties of the material itself or internal defects on the propagation of ultrasonic waves is utilized to non-destructively detect the defects inside and on the surface of the raw materials. It has the advantages of high detection efficiency, good stability, high degree of automation, and small detection blind area, and can be widely used in various fields such as machinery manufacturing, transportation, national defense, and electric power.

[0017] At the same time, in the embodiment of the present application, when the ultrasonic probe detects the raw material, the distance between the ultrasonic probe and the raw material directly affects the strength of the reflected signal and the imaging resolution. When the distance is too large, the energy attenuation of the sound beam in the water is large, so that the sound energy is reduced when it propagates to the surface of the raw material, resulting in a weak reflected wave signal and difficulty in extracting characteristic signals; if the distance is too small, the bottom wave and the secondary echo inside the raw material will be confused. Therefore, the embodiment of the present application obtains the optimal distance between the ultrasonic probe and the raw material according to the preset distance calculation strategy, and arranges the ultrasonic probe according to the optimal distance, which can effectively improve the reflected wave strength and imaging resolution; Furthermore, the embodiment of the present application controls the manipulator to drive the radial rotation of the raw material, and the ultrasonic probe moves axially while emitting ultrasonic waves to the raw material, thereby achieving a comprehensive coverage scan of the raw material without missing any detections; segmenting the ultrasonic image can effectively improve the accuracy and efficiency of defect identification.

[0018] In addition, the embodiment of the present application uses a coupling agent during ultrasonic flaw detection. The coupling agent is mainly used between the raw material and the probe to allow the ultrasonic wave to be transmitted to the raw material. The coupling agent can also reduce the contact friction between the probe and the surface of the raw material, thereby reducing the loss of the ultrasonic probe. The coupling agent can generally be selected from industrial coupling agents, engine oil, water, glycerin, etc. The embodiment of the present application uses water as a coupling agent to effectively save detection costs.

[0019] A second aspect of an embodiment of the present application provides a vacuum isothermal forging raw material flaw detection system, comprising: A calculation module is used to fill a predetermined amount of water into the detection tank before vacuum isothermal forging, grab the raw material through the manipulator, and completely immerse the raw material in the water, obtain the optimal distance between the ultrasonic probe and the raw material according to the preset distance calculation strategy, and arrange the ultrasonic probe according to the optimal distance; An imaging module is used to control the manipulator to drive the raw material to rotate radially, and the ultrasonic probe to move axially while emitting ultrasonic waves to the raw material, and to obtain an ultrasonic image through the reflected wave signal of the ultrasonic wave, and to segment the ultrasonic image to obtain a target image; The execution module is used to retrieve the raw material drawings associated with the raw material identification according to the raw material identification, distinguish the raw material types through the raw material drawings, adopt different flaw detection strategies for the target image according to different raw material types, obtain the number of defective pixels, and calculate the availability of the raw materials according to the number of defective pixels.

[0020] A third aspect of an embodiment of the present application provides a terminal, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the method described in the first aspect when executing the computer program.

[0021] A fourth aspect of an embodiment of the present application provides 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 steps of the method described in the first aspect are implemented.

[0022] A fifth aspect of the present application provides a computer program product, which, when executed on a terminal, enables the terminal to execute the steps of the method described in the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application, 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 application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0024] Figure 1 It is a schematic flow chart of a method for flaw detection of vacuum isothermal forging raw materials provided in an embodiment of the present application; Figure 2 It is a structural schematic diagram of a vacuum isothermal forging raw material flaw detection system provided in an embodiment of the present application; Figure 3 It is a structural diagram of a terminal provided in an embodiment of the present application. DETAILED DESCRIPTION

[0025] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0026] It should be understood that when used in this specification and the appended claims, the term "comprising" indicates the presence of described features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof.

[0027] It should be further understood that the terms used in this application specification are only for the purpose of describing specific embodiments and are not intended to limit the application. As used in this application specification and the appended claims, the singular forms "a", "an" and "the" are intended to include plural forms unless the context clearly indicates otherwise.

[0028] It should be further understood that the term “and / or” used in the specification and appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0029] It should be further understood that the size of the serial numbers of the steps in this embodiment does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present application.

[0030] In order to illustrate the technical solution described in this application, a specific embodiment is provided below for illustration.

[0031] See also Figure 1 , Figure 1 Schematic diagram of a process flow of a vacuum isothermal forging raw material flaw detection method provided in an embodiment of the present application. Figure 1As shown, a method for flaw detection of vacuum isothermal forging raw materials comprises the following steps: Step 1: before vacuum isothermal forging, a predetermined amount of water is filled into the test tank, the raw material is grabbed by a manipulator, and the raw material is completely immersed in the water, the optimal distance between the ultrasonic probe and the raw material is obtained according to a preset distance calculation strategy, and the ultrasonic probe is arranged according to the optimal distance; Step 2, controlling the manipulator to drive the raw material to rotate radially, and the ultrasonic probe to move axially while emitting ultrasonic waves to the raw material, imaging the reflected wave signal of the ultrasonic wave to obtain an ultrasonic image, and segmenting the ultrasonic image to obtain a target image; Step 3: According to the raw material identification, retrieve the raw material drawing associated with the identification, distinguish the raw material type through the raw material drawing, adopt different flaw detection strategies for the target image according to the different raw material types, obtain the number of defective pixels, and calculate the availability of the raw material according to the number of defective pixels.

[0032] It can be seen that the embodiment of the present application adopts a water immersion ultrasonic flaw detection method for vacuum isothermal forging raw materials, that is, the ultrasonic probe and the raw materials are immersed in water, water is used as a coupling agent, and ultrasonic waves are emitted to the raw materials through the water. The influence of the acoustic properties of the material itself or internal defects on the propagation of ultrasonic waves is utilized to non-destructively detect defects inside and on the surface of the raw materials. This method has the advantages of high detection efficiency, good stability, high degree of automation, and small detection blind area, and can be widely used in various fields such as machinery manufacturing, transportation, national defense, and electric power.

[0033] At the same time, when the ultrasonic probe detects the raw material, the distance between the ultrasonic probe and the raw material directly affects the strength of the reflected signal and the imaging resolution. When the distance is too large, the energy attenuation of the sound beam in the water is large, so that the sound energy is reduced when it propagates to the surface of the raw material, resulting in a weak reflected wave signal and difficulty in extracting characteristic signals; if the distance is too small, the bottom wave and the secondary echo inside the raw material will be confused. Therefore, the embodiment of the present application obtains the optimal distance between the ultrasonic probe and the raw material according to the preset distance calculation strategy, and arranges the ultrasonic probe according to the optimal distance, which can effectively improve the reflected wave strength and imaging resolution; Furthermore, the embodiment of the present application controls the manipulator to drive the radial rotation of the raw material, and the ultrasonic probe moves axially while emitting ultrasonic waves to the raw material, thereby achieving a comprehensive coverage scan of the raw material without missing any detections; segmenting the ultrasonic image can effectively improve the accuracy and efficiency of defect identification.

[0034] In addition, coupling agents are used during ultrasonic flaw detection. The coupling agents are mainly used between the raw materials and the probe to allow ultrasonic waves to be transmitted to the raw materials. The coupling agents can also reduce the contact friction between the probe and the surface of the raw materials, thereby reducing the loss of the ultrasonic probe. The coupling agents can generally be selected from industrial coupling agents, engine oil, water, glycerin, etc. The use of water as a coupling agent in the embodiment of the present application can effectively save detection costs.

[0035] In the embodiment of the present application, step 1, before performing vacuum isothermal forging, a predetermined amount of water is filled into the detection tank, a raw material is grabbed by a manipulator, and the raw material is completely immersed in water, and the optimal distance between the ultrasonic probe and the raw material is obtained according to a preset distance calculation strategy, and the ultrasonic probe is arranged according to the optimal distance, wherein the optimal distance between the ultrasonic probe and the raw material is obtained according to the preset distance calculation strategy, including the following contents: Step 11, discretizing the preset distance interval according to the preset discrete step distance to obtain a plurality of different interval values; Step 12, using a cyclic calculation method, by using a preset ultrasonic measurement model, to calculate the ultrasonic reflected wave voltage amplitude corresponding to different spacing values; Step 13, performing a fitting operation on the ultrasonic reflected wave voltage amplitudes corresponding to different spacing values ​​to obtain a discrete reflected wave voltage amplitude variation curve; Step 14, calculating the maximum reflected wave voltage amplitude in the curve, and taking the spacing value corresponding to the maximum echo voltage amplitude as the optimal spacing between the ultrasonic probe and the raw material.

[0036] When testing the quality of raw materials, whether there are defects is determined by comparing the changes in the amplitude of the reflected wave reflected from the raw materials. A weak reflected wave signal will reduce the signal-to-noise ratio, which will lead to difficulty in extracting characteristic signals and low imaging resolution. To improve this problem, the embodiment of the present application optimizes the distance between the ultrasonic probe and the raw material so that the raw material is in the area with the maximum sound intensity in the sound field radiated by the ultrasonic probe, thereby improving the intensity of the reflected wave signal.

[0037] The embodiment of the present application adopts a cyclic calculation method combined with a preset ultrasonic measurement model to calculate the ultrasonic reflected wave voltage amplitudes corresponding to different spacing values, and selects the optimal spacing value through the strongest reflected wave voltage amplitude, thereby effectively saving calculation costs and improving calculation speed.

[0038] For example, in step 12, a cyclic calculation method is used to calculate the ultrasonic reflected wave voltage amplitude corresponding to different spacing values ​​through a preset ultrasonic measurement model, wherein the preset ultrasonic measurement model may include the following contents: Step 121, calculating the vibration velocity of any particle in the sound field radiated by the ultrasonic probe by superimposing multiple (for example, 10 to 15) single Gaussian sound beams; Step 122, integrating the vibration velocity of the particles on the surface of the ultrasonic probe to obtain the receiving impedance of the probe surface; Step 123, obtaining an acoustic elastic propagation function describing the law between the probe transmitting and receiving reflected waves according to the probe surface receiving impedance and output impedance; Step 124: Obtain an ultrasonic measurement model according to the acoustic elastic propagation function and the pulse excitation system function.

[0039] Specifically, in step 123, according to the receiving impedance and output impedance of the probe surface, an acoustic elastic propagation function describing the law between the probe transmitting and receiving reflected waves is obtained, wherein the acoustic elastic propagation function can be expressed by the following formula: In the above formula, represents the acoustic elastic propagation function, Indicates the receiving impedance of the probe surface. It indicates the output impedance of the probe surface. When a circular plane probe is used for detection, the output impedance of the probe surface is considered to be a constant.

[0040] Specifically, in step 124, an ultrasonic measurement model is obtained according to the acoustic elastic propagation function and the pulse excitation system function, wherein the pulse excitation system function is determined according to factors such as equivalent voltage, pulse electrical impedance, probe electrical impedance and sensitivity during ultrasonic detection, and can also be obtained by an experimental test method, which is not limited here; The ultrasonic measurement model can be expressed by the following formula: In the above formula, represents the frequency domain characteristics of the reflected wave voltage, represents the impulse excitation system function, represents the acoustic elastic propagation function.

[0041] Among them, the time domain reflection wave response can be obtained by performing inverse Fourier transform on the frequency domain signal.

[0042] In the embodiment of the present application, step 2 is to control the manipulator to drive the raw material to rotate radially, and the ultrasonic probe moves axially while emitting ultrasonic waves to the raw material, and to obtain an ultrasonic image by imaging the reflected wave signal of the ultrasonic wave, and to segment the ultrasonic image to obtain a target image, wherein segmenting the ultrasonic image to obtain the target image may include the following contents: Step 21, setting the direction parameter of the Gabor filter to a set of continuous values, selecting a set of Gabor filters in different directions to filter the ultrasound image, and fusing them through the maximum value of pixel grayscale to obtain a first intermediate image; Step 22, filtering the first intermediate image by using a multi-center frequency Gabor filter, and fusing the image by using a mean fusion method to obtain a second intermediate image; Step 23, using the level set method, calculate the edges in the second intermediate image, and obtain the target image according to the edge segmentation.

[0043] Since the texture direction of ultrasound images is relatively messy and the spectrum distribution is complex, the embodiment of the present application processes the ultrasound image from various directions and different frequencies through a Gabor filter, which can not only weaken the texture of the ultrasound image and enhance the difference between the foreground and background to be segmented, but also use the mean fusion method to perform image fusion, which can retain the useful information of the ultrasound image to the greatest extent and reduce the influence of noise, thereby facilitating subsequent image segmentation.

[0044] In order to accurately perform data analysis and improve the reliability of defect assessment and defect area statistical results, this embodiment may also include: Step 24, converting the color information of the target image into amplitude information, may specifically include the following contents: The (R, G, B) value of each pixel in the target image The (R, G, B) value of each pixel in the color band Perform a one-by-one comparison; When the (R, G, B) value at the (x, y) coordinate position of the target image is closest to the (R, G, B) value of the i-th pixel of the color band, the amplitude at the (x, y) coordinate position of the target image is the amplitude corresponding to the i-th pixel of the color band, which can be expressed by the following formula: In the above formula, Represents the amplitude at the (x, y) coordinate position of the target image, Represents the (R, G, B) value at the (x, y) coordinate pixel in the target image. is the (R, G, B) value at the i-th pixel of the color band.

[0045] Obviously, through the above-mentioned scheme of the embodiment of the present application, the three-dimensional array of the RGB mode corresponding to the target image can be converted into a two-dimensional amplitude matrix, which is convenient for data calculation and / or statistics.

[0046] In the embodiment of the present application, step 3, according to the raw material identification, retrieve the raw material drawing associated with the identification, distinguish the raw material type through the raw material drawing, adopt different flaw detection strategies for the target image according to different raw material types, obtain the number of defective pixels, and calculate the availability of the raw material according to the number of defective pixels, where: When the raw material being inspected has structural features, for example, there are complex airways or grooves inside the raw material, if the depth of the defect is very close to the depth of the structural feature, the structural feature and the defect will appear in the ultrasonic image at the same time. In order to detect small defects, the sensitivity of ultrasonic detection is generally high, and the signal amplitudes of the structural features and defects are displayed on the full screen. It is also difficult to distinguish the two from the amplitude. At this time, the existence of structural features will seriously affect the automatic identification of defects and the analysis and calculation of defect areas.

[0047] Based on this, the embodiment of the present application distinguishes the raw material types through the raw material drawings, and adopts different flaw detection strategies for the target image according to the different raw material types, wherein the raw material types include those without structural features and those with structural features.

[0048] Accordingly, different flaw detection strategies are adopted for the target image to obtain the number of defective pixels. According to the number of defective pixels, the availability of raw materials is calculated, which may include the following: When there are no structural features, the target image is identified by setting the defect amplitude threshold, and the number of pixels within the amplitude threshold is counted as the number of defective pixels. The raw material availability is calculated based on the number of defective pixels and the number of overall pixels. When there are structural features, check the complex structural features and key areas and non-key areas in the target image, and store the structural feature parameters for automatic import of the structural feature parameters of the same batch of raw materials. Then, by setting the width information of the structural features, the amplitude within the structural features is set to zero to eliminate its impact on the defect area statistical results. Finally, the number of pixels of defects in the key areas and non-key areas are counted separately, and the availability of the raw materials is calculated based on the number of defective pixels and the overall number of pixels.

[0049] Obviously, the embodiment of the present application can quickly and accurately detect whether the raw materials are damaged or not, even in batches, through the above-mentioned scheme.

[0050] See also Figure 2 , Figure 2 This is a structural schematic diagram of a flaw detection system for vacuum isothermal forging raw materials provided in an embodiment of the present application. For ease of explanation, only the parts related to the embodiment of the present application are shown.

[0051] The vacuum isothermal forging raw material flaw detection system comprises: The calculation module 1 is used to fill a predetermined amount of water into the detection tank before vacuum isothermal forging, grab the raw material by the manipulator, and immerse the raw material completely in the water, obtain the optimal distance between the ultrasonic probe and the raw material according to the preset distance calculation strategy, and arrange the ultrasonic probe according to the optimal distance; Image module 2, used to control the manipulator to drive the raw material to rotate radially, the ultrasonic probe to move axially and transmit ultrasonic waves to the raw material at the same time, to obtain an ultrasonic image through the reflected wave signal of the ultrasonic wave, and to segment the ultrasonic image to obtain a target image; Execution module 3 is used to retrieve the raw material drawings associated with the raw material identification according to the raw material identification, distinguish the raw material types through the raw material drawings, adopt different flaw detection strategies for the target image according to different raw material types, obtain the number of defective pixels, and calculate the availability of the raw materials according to the number of defective pixels.

[0052] It can be seen that the embodiment of the present application adopts a water immersion ultrasonic flaw detection method for vacuum isothermal forging raw materials, that is, the ultrasonic probe and the raw materials are immersed in water, water is used as a coupling agent, and ultrasonic waves are emitted to the raw materials through the water. The influence of the acoustic properties of the material itself or internal defects on the propagation of ultrasonic waves is utilized to non-destructively detect defects inside and on the surface of the raw materials. This method has the advantages of high detection efficiency, good stability, high degree of automation, and small detection blind area, and can be widely used in various fields such as machinery manufacturing, transportation, national defense, and electric power.

[0053] At the same time, when the ultrasonic probe detects the raw material, the distance between the ultrasonic probe and the raw material directly affects the strength of the reflected signal and the imaging resolution. When the distance is too large, the energy attenuation of the sound beam in the water is large, so that the sound energy is reduced when it propagates to the surface of the raw material, resulting in a weak reflected wave signal and difficulty in extracting characteristic signals; if the distance is too small, the bottom wave and the secondary echo inside the raw material will be confused. Therefore, the embodiment of the present application obtains the optimal distance between the ultrasonic probe and the raw material according to the preset distance calculation strategy, and arranges the ultrasonic probe according to the optimal distance, which can effectively improve the reflected wave strength and imaging resolution; Furthermore, the embodiment of the present application controls the manipulator to drive the radial rotation of the raw material, and the ultrasonic probe moves axially while emitting ultrasonic waves to the raw material, thereby achieving a comprehensive coverage scan of the raw material without missing any detections; segmenting the ultrasonic image can effectively improve the accuracy and efficiency of defect identification.

[0054] In addition, coupling agents are used during ultrasonic flaw detection. The coupling agents are mainly used between the raw materials and the probe to allow ultrasonic waves to be transmitted to the raw materials. The coupling agents can also reduce the contact friction between the probe and the surface of the raw materials, thereby reducing the loss of the ultrasonic probe. The coupling agents can generally be selected from industrial coupling agents, engine oil, water, glycerin, etc. The use of water as a coupling agent in the embodiment of the present application can effectively save detection costs.

[0055] Figure 3 is a structural diagram of a terminal provided in an embodiment of the present application. As shown in the figure, the terminal 3 of this embodiment includes: at least one processor 30 ( Figure 3Only one is shown in the figure), a memory 31, and a computer program 32 stored in the memory 31 and executable on the at least one processor 30, wherein the processor 30 implements the steps of any of the above-mentioned method embodiments when executing the computer program 32.

[0056] The terminal 3 may be a computing device such as a desktop computer, a notebook, a PDA, or a cloud server. The terminal 3 may include, but is not limited to, a processor 30 and a memory 31. Those skilled in the art will appreciate that Figure 3 It is only an example of terminal 3 and does not constitute a limitation on terminal 3. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the terminal may also include input and output devices, network access devices, buses, etc.

[0057] The processor 30 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0058] The memory 31 may be an internal storage unit of the terminal 3, such as a hard disk or memory of the terminal 3. The memory 31 may also be an external storage device of the terminal 3, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the terminal 3. Further, the memory 31 may also include both an internal storage unit and an external storage device of the terminal 3. The memory 31 is used to store the computer program and other programs and data required by the terminal. The memory 31 may also be used to temporarily store data that has been output or is to be output.

[0059] In a specific implementation, the terminal described in the embodiments of the present application includes, but is not limited to, other portable devices such as mobile phones, laptop computers, or tablet computers with touch-sensitive surfaces (e.g., touch screen displays and / or touch pads). It should also be understood that in some embodiments, the device is not a portable communication device, but a desktop computer with a touch-sensitive surface (e.g., touch screen displays and / or touch pads).

[0060] The terminal supports various applications, such as one or more of the following: a drawing application, a presentation application, a word processing application, a website creation application, a disk burning application, a spreadsheet application, a game application, a telephone application, a video conferencing application, an email application, an instant messaging application, a workout support application, a photo management application, a digital camera application, a digital camcorder application, a web browsing application, a digital music player application, and / or a digital video player application.

[0061] Various applications that can be executed on the terminal can use at least one common physical user interface device such as a touch-sensitive surface. One or more functions of the touch-sensitive surface and corresponding information displayed on the terminal can be adjusted and / or changed between applications and / or within corresponding applications. In this way, the common physical architecture of the terminal (e.g., the touch-sensitive surface) can support various applications with user interfaces that are intuitive and transparent to the user.

[0062] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0063] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0064] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0065] In the embodiments provided in the present application, it should be understood that the disclosed devices / terminals and methods can be implemented in other ways. For example, the device / terminal embodiments described above are only schematic. For example, the division of the modules or units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0066] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0067] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0068] If the integrated module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present application implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned various method embodiments when executed by the processor. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), electric carrier signal, telecommunication signal and software distribution medium. It should be noted that the content contained in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media do not include electric carrier signals and telecommunication signals.

[0069] The present application implements all or part of the processes in the above-mentioned embodiment method, and may also be implemented through a computer program product. When the computer program product runs on a terminal, the terminal can implement the steps in the above-mentioned method embodiments when executing the computer program product.

[0070] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A method for flaw detection of vacuum isothermal forging raw materials, characterized in that: include: Before vacuum isothermal forging, a predetermined amount of water is filled into the test tank, the raw material is grabbed by a manipulator and completely immersed in water, the optimal distance between the ultrasonic probe and the raw material is obtained according to the preset distance calculation strategy, and the ultrasonic probe is arranged according to the optimal distance; The manipulator is controlled to drive the raw material to rotate radially, and the ultrasonic probe moves axially while emitting ultrasonic waves to the raw material. The ultrasonic reflected wave signal is used to obtain an ultrasonic image, and the ultrasonic image is segmented to obtain a target image. According to the raw material identification, the raw material drawings associated with the identification are retrieved, and the raw material types are distinguished by the raw material drawings. According to different raw material types, different flaw detection strategies are adopted for the target image to obtain the number of defective pixels. According to the number of defective pixels, the availability of the raw materials is calculated.

2. The method for flaw detection of vacuum isothermal forging raw materials according to claim 1, characterized in that: Before the vacuum isothermal forging is performed, a predetermined amount of water is filled into the detection tank, the raw material is grabbed by a manipulator, and the raw material is completely immersed in the water, and the optimal distance between the ultrasonic probe and the raw material is obtained according to a preset distance calculation strategy, and the ultrasonic probe is arranged according to the optimal distance, wherein the optimal distance between the ultrasonic probe and the raw material is obtained according to the preset distance calculation strategy, including the following contents: According to the preset discrete step distance, the preset distance interval is discretized to obtain multiple different interval values; The cyclic calculation method is used to calculate the voltage amplitude of the ultrasonic reflected wave corresponding to different spacing values ​​through the preset ultrasonic measurement model; The ultrasonic reflected wave voltage amplitudes corresponding to different spacing values ​​are fitted to obtain a discrete reflected wave voltage amplitude variation curve; The maximum reflected wave voltage amplitude in the curve is calculated, and the spacing value corresponding to the maximum echo voltage amplitude is used as the optimal spacing between the ultrasonic probe and the raw material.

3. The method for flaw detection of vacuum isothermal forging raw materials according to claim 2, characterized in that: The cyclic calculation method is used to calculate the ultrasonic reflected wave voltage amplitude corresponding to different spacing values ​​through a preset ultrasonic measurement model, wherein the preset ultrasonic measurement model includes the following contents: By superimposing multiple single Gaussian sound beams, the vibration velocity of any particle in the sound field radiated by the ultrasonic probe is calculated; Integrate the vibration velocity of the particle on the surface of the ultrasonic probe to obtain the receiving impedance of the probe surface; According to the receiving impedance and output impedance of the probe surface, the acoustic elastic propagation function describing the law between the probe transmitting and receiving reflected waves is obtained; According to the acoustic elastic propagation function and the pulse excitation system function, the ultrasonic measurement model is obtained.

4. The method for flaw detection of vacuum isothermal forging raw materials according to claim 3, characterized in that: According to the receiving impedance and output impedance of the probe surface, an acoustic elastic propagation function describing the law between the probe transmitting and receiving reflected waves is obtained, wherein the acoustic elastic propagation function is expressed by the following formula: In the above formula, represents the acoustic elastic propagation function, Indicates the receiving impedance of the probe surface. It indicates the output impedance of the probe surface. When a circular plane probe is used for detection, the output impedance of the probe surface is considered to be a constant.

5. The method for flaw detection of vacuum isothermal forging raw materials according to claim 3, characterized in that: The ultrasonic measurement model is obtained according to the acoustic elastic propagation function and the pulse excitation system function, wherein the pulse excitation system function is determined according to the equivalent voltage, pulse electrical impedance, probe electrical impedance and sensitivity during ultrasonic detection, or is obtained by an experimental test method; The ultrasonic measurement model is expressed by the following formula: In the above formula, represents the frequency domain characteristics of the reflected wave voltage, represents the impulse excitation system function, represents the acoustic elastic propagation function.

6. The method for flaw detection of vacuum isothermal forging raw materials according to claim 1, characterized in that: The control manipulator drives the raw material to rotate radially, and the ultrasonic probe moves axially while emitting ultrasonic waves to the raw material, imaging is performed through the reflected wave signal of the ultrasonic wave to obtain an ultrasonic image, and the ultrasonic image is segmented to obtain a target image, wherein the ultrasonic image is segmented to obtain the target image, including the following contents: A set of continuous values ​​is set for the direction parameter of the Gabor filter, a set of Gabor filters with different directions is selected to filter the ultrasound image, and the image is fused by the maximum value of the pixel grayscale to obtain a first intermediate image; The first intermediate image is filtered by a multi-center frequency Gabor filter, and is fused by a mean fusion method to obtain a second intermediate image; The level set method is used to calculate the edges in the second intermediate image, and the target image is obtained by segmentation based on the edges.

7. The method for flaw detection of vacuum isothermal forging raw materials according to claim 6, characterized in that: Also includes: Convert the color information of the target image into amplitude information, including the following: The (R, G, B) value of each pixel in the target image The (R, G, B) value of each pixel in the color band Perform a one-by-one comparison; When the (R, G, B) value at the (x, y) coordinate position of the target image is closest to the (R, G, B) value of the i-th pixel of the color band, the amplitude at the (x, y) coordinate position of the target image is the amplitude corresponding to the i-th pixel of the color band.

8. The method for flaw detection of vacuum isothermal forging raw materials according to claim 1, characterized in that: According to the raw material identification, the raw material drawing associated with the identification is retrieved, the raw material type is distinguished by the raw material drawing, and different flaw detection strategies are adopted for the target image according to different raw material types to obtain the number of defective pixels, and the availability of the raw material is calculated according to the number of defective pixels, wherein: the raw material type includes those without structural features and those with structural features.

9. The method for flaw detection of vacuum isothermal forging raw materials according to claim 8, characterized in that: The method adopts different flaw detection strategies for the target image to obtain the number of defective pixels, and calculates the availability of the raw materials according to the number of defective pixels, which specifically includes the following contents: When there are no structural features, the target image is identified by setting the defect amplitude threshold, and the number of pixels within the amplitude threshold is counted as the number of defective pixels. The raw material availability is calculated based on the number of defective pixels and the number of overall pixels. When there are structural features, check the complex structural features and key areas and non-key areas in the target image; then set the width information of the structural features to zero the amplitude within the structural features; finally, count the number of pixels of defects in the key areas and non-key areas respectively, and calculate the availability of the raw materials based on the number of defective pixels and the overall number of pixels.

10. A flaw detection system for vacuum isothermal forging raw materials, characterized in that: include: A calculation module is used to fill a predetermined amount of water into the detection tank before vacuum isothermal forging, grab the raw material through the manipulator, and completely immerse the raw material in the water, obtain the optimal distance between the ultrasonic probe and the raw material according to the preset distance calculation strategy, and arrange the ultrasonic probe according to the optimal distance; An imaging module is used to control the manipulator to drive the raw material to rotate radially, and the ultrasonic probe to move axially while emitting ultrasonic waves to the raw material, and to obtain an ultrasonic image through the reflected wave signal of the ultrasonic wave, and to segment the ultrasonic image to obtain a target image; The execution module is used to retrieve the raw material drawings associated with the raw material identification according to the raw material identification, distinguish the raw material types through the raw material drawings, adopt different flaw detection strategies for the target image according to different raw material types, obtain the number of defective pixels, and calculate the availability of the raw materials according to the number of defective pixels.

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