Acoustic emission positioning method, device and equipment

Abstract

The embodiment of the invention provides an acoustic emission positioning method, device and equipment. The method comprises the following steps: acquiring time domain waveform data of an acoustic emission event of an observation target on a plurality of channels through acquisition equipment; according to the multi-channel time domain waveform data of the acoustic emission event, obtaining a preliminary positioning result of the acoustic emission event by adopting a cross-correlation algorithm; for the time-domain waveform data of each channel, intercepting the time-domain waveform data within a preset duration before and after the arrival time of the impact signal by adopting a preset window function to obtain multi-channel local time-domain waveform data of the acoustic emission event; acquiring a spectrum envelope corresponding to the multi-channel local time domain waveform data of the acoustic emission event; and according to the frequency spectrum envelope, correcting the preliminary positioning result by adopting a coherent superposition algorithm to obtain a final positioning result of the acoustic emission event. Local waveform spectrum envelope is used as a characteristic function, waveform generality of the same acoustic emission event distributed in different channels is amplified, noise interference can be overcome, and positioning precision is improved.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of geophysical monitoring, and particularly to an acoustic emission positioning method, device and equipment. Background Art

[0002] Rock mechanics research is an important technical means to solve the stability problems of rock engineering in the construction of water conservancy, civil engineering, etc. Acoustic emission monitoring technology has been widely used in the research of indoor rock mechanical properties. By obtaining the distribution characteristics of acoustic emission parameters such as energy, count, and amplitude over time, the monitoring of internal damage activities of rock samples at different characteristic stress stages can be realized. However, the distribution characteristics of acoustic emission parameters over time can only qualitatively describe the failure process of rocks. In order to obtain higher-precision acoustic data, acoustic emission positioning technology has developed rapidly as a quantitative characterization means.

[0003] Existing acoustic emission positioning technologies mainly perform positioning based on the arrival time information or waveform information of acoustic emissions. Among them, in the methods based on arrival time information for positioning, first, the arrival time of the impact signal needs to be picked up, and then in the acquisition stage, by setting the signal voltage threshold value, when the voltage value of the impact signal exceeds the threshold at a certain moment, the time is recorded, and finally, the time difference between the arrival times of different impact signals is used for positioning; in the methods based on waveform information for positioning, the waveform superposition method is one of the most widely used. The core content is to perform positioning using the similarity of initial phase information. The algorithm is based on scattering superposition and cross-correlation superposition algorithms. More classic ones include Kirchhoff, coherent superposition and other methods. However, whether it is the method of positioning based on arrival time information or the method of positioning based on waveform information, it is vulnerable to noise interference, has a large positioning error, and is difficult to meet the actual application requirements. Summary of the Invention

[0004] The embodiments of the present invention provide an acoustic emission positioning method, device and equipment to solve the problems that the existing acoustic emission positioning methods are vulnerable to noise interference and have a large positioning error.

[0005] In a first aspect, the embodiments of the present invention provide an acoustic emission positioning method, including:

[0006] Collect the time-domain waveform data of the acoustic emission events of the observation target on multiple channels through a collection device to obtain the multi-channel time-domain waveform data of the acoustic emission events;

[0007] According to the multi-channel time-domain waveform data of the acoustic emission events, adopt the cross-correlation algorithm to obtain the preliminary positioning result of the acoustic emission events;

[0008] For the time-domain waveform data of each channel, intercept the time-domain waveform data within a preset time period before and after the arrival time of the impact signal by using a preset window function to obtain the multi-channel local time-domain waveform data of the acoustic emission events;

[0009] Obtain the spectral envelope corresponding to the multi-channel local time-domain waveform data of the acoustic emission event;

[0010] According to the spectral envelope, use the coherent superposition algorithm to correct the preliminary positioning result to obtain the final positioning result of the acoustic emission event.

[0011] In one embodiment, according to the multi-channel time-domain waveform data of the acoustic emission event, use the cross-correlation algorithm to obtain the preliminary positioning result of the acoustic emission event, including:

[0012] According to the multi-channel time-domain waveform data of the acoustic emission event, use the cross-correlation algorithm to determine the arrival time of the impact signal on each channel;

[0013] Obtain the preliminary positioning result of the acoustic emission event according to the arrival time difference of the impact signals of the acoustic emission event on different channels.

[0014] In one embodiment, use a preset window function to intercept the time-domain waveform data within a preset duration before and after the arrival time of the impact signal, including:

[0015] Obtain the waveform delay time according to the multi-channel time-domain waveform data of the acoustic emission event, and determine the time window length according to the waveform delay time;

[0016] Take the takeoff position corresponding to the acquisition threshold value as the reference point, and use a preset window function to intercept the time-domain waveform data within a quarter of the time window length before the reference point and within one time window length after the reference point.

[0017] In one embodiment, the acquisition threshold value is determined according to the lithology and size of the core.

[0018] In one embodiment, according to the spectral envelope, use the coherent superposition algorithm to correct the preliminary positioning result to obtain the final positioning result of the acoustic emission event, including:

[0019] Input the spectral envelope into the coherent superposition algorithm to obtain a positioning map;

[0020] Determine the position with the maximum correlation energy in the positioning map as the final positioning result of the acoustic emission event.

[0021] In one embodiment, the preset window function includes a Gaussian window function, a Hamming window function, and a trapezoidal window function.

[0022] In one embodiment, the acquisition device includes at least four acoustic emission receiving sensors not in the same plane.

[0023] In a second aspect, an embodiment of the present invention provides an acoustic emission positioning device, including:

[0024] An acquisition module, configured to acquire time-domain waveform data of acoustic emission events of an observation target on multiple channels through an acquisition device, so as to obtain multi-channel time-domain waveform data of the acoustic emission events;

[0025] A processing module, configured to obtain a preliminary positioning result of the acoustic emission event by using a cross-correlation algorithm according to the multi-channel time-domain waveform data of the acoustic emission event;

[0026] A truncation module, configured to, for the time-domain waveform data of each channel, truncate the time-domain waveform data within a preset time period before and after the arrival time of the impact signal by using a preset window function, so as to obtain multi-channel local time-domain waveform data of the acoustic emission event;

[0027] An acquisition module, configured to acquire a spectral envelope corresponding to the multi-channel local time-domain waveform data of the acoustic emission event;

[0028] A correction module, configured to correct the preliminary positioning result by using a coherent superposition algorithm according to the spectral envelope, so as to obtain a final positioning result of the acoustic emission event.

[0029] In a third aspect, an embodiment of the present invention provides an electronic device, including:

[0030] At least one processor and a memory;

[0031] The memory stores computer-executable instructions;

[0032] At least one processor executes the computer-executable instructions stored in the memory, so that at least one processor executes the acoustic emission positioning method according to any one of the first aspect.

[0033] In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium, in which computer-executable instructions are stored, and when the computer-executable instructions are executed by a processor, they are used to implement the acoustic emission positioning method according to any one of the first aspect.

[0034] The acoustic emission positioning method, device and equipment provided by the embodiments of the present invention collect the time-domain waveform data of the acoustic emission events of the observation target on multiple channels through the acquisition device to obtain the multi-channel time-domain waveform data of the acoustic emission events; according to the multi-channel time-domain waveform data of the acoustic emission events, the cross-correlation algorithm is used to obtain the preliminary positioning result of the acoustic emission events; for the time-domain waveform data of each channel, the preset window function is used to intercept the time-domain waveform data within a preset time period before and after the arrival time of the impact signal to obtain the multi-channel local time-domain waveform data of the acoustic emission events; the spectral envelope corresponding to the multi-channel local time-domain waveform data of the acoustic emission events is obtained; according to the spectral envelope, the coherent superposition algorithm is used to correct the preliminary positioning result to obtain the final positioning result of the acoustic emission events. Using the local waveform spectral envelope as the characteristic function amplifies the waveform commonality of the same acoustic emission event distributed on different channels, can overcome the interference of noise, and improve the positioning accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings herein are incorporated into the specification and constitute a part of the specification, showing embodiments consistent with the present invention and, together with the specification, are used to explain the principles of the present invention.

[0036] Figure 1 It is a flowchart of the acoustic emission positioning method provided by an embodiment of the present invention;

[0037] Figure 2 It is a radial section view of a two-dimensional rock sample provided by an embodiment of the present invention;

[0038] Figure 3 It is a schematic diagram of the true position of the acoustic emission event and the projection position of the sensor provided by an embodiment of the present invention;

[0039] Figure 4 It is a schematic diagram of the wave field snapshot during the propagation process of the acoustic emission signal provided by an embodiment of the present invention;

[0040] Figure 5 It is a schematic diagram of the time-domain waveform of the impact signal received by each channel provided by an embodiment of the present invention;

[0041] Figure 6 It is a schematic diagram of the preliminary positioning result provided by an embodiment of the present invention;

[0042] Figure 7 It is a schematic diagram of the intercepted local time-domain waveform provided by an embodiment of the present invention;

[0043] Figure 8 is Figure 7 a schematic diagram of the spectral envelope corresponding to the signal shown in

[0044] Figure 9 It is a schematic diagram of the final positioning result provided by an embodiment of the present invention;

[0045] Figure 10 Structural schematic diagram of an acoustic emission positioning device provided by an embodiment of the present invention;

[0046] Figure 11 Structural schematic diagram of an electronic device provided by an embodiment of the present invention.

[0047] Through the above-mentioned drawings, specific embodiments of the present invention have been shown, and more detailed descriptions will be provided hereinafter. These drawings and textual descriptions are not intended to limit the scope of the inventive concept in any way, but to illustrate the concept of the present invention to those skilled in the art by referring to specific embodiments. Detailed embodiments

[0048] The present invention will be further described in detail below in conjunction with the accompanying drawings through specific embodiments. Similar elements in different embodiments are labeled with related similar element numbers. In the following embodiments, many detailed descriptions are provided to enable a better understanding of the present application. However, those skilled in the art can easily recognize that some of the features can be omitted in different situations, or can be replaced by other elements, materials, or methods. In some cases, some operations related to the present application are not shown or described in the specification to avoid submerging the core part of the present application in excessive descriptions. For those skilled in the art, it is not necessary to describe these related operations in detail, and they can fully understand the related operations based on the descriptions in the specification and general technical knowledge in the art.

[0049] In addition, the features, operations, or characteristics described in the specification can be combined in any appropriate manner to form various embodiments. At the same time, the steps or actions in the method description can also be reordered or adjusted in a manner obvious to those skilled in the art. Therefore, the various sequences in the specification and drawings are only for clearly describing a certain embodiment and do not mean that they are necessary sequences, unless it is stated that a certain sequence must be followed.

[0050] The serial numbers assigned to the components herein, such as "first", "second", etc., are only used to distinguish the described objects and do not have any sequential or technical meaning. The "connection" and "coupling" mentioned in the present application, unless otherwise specified, both include direct and indirect connection (coupling).

[0051] In order to obtain higher-precision acoustic data, acoustic emission source localization technology has developed rapidly as a quantitative characterization method. Locating based on the arrival-time information and waveform information of acoustic emissions are currently two mainstream acoustic emission localization methods. Among the methods based on arrival-time information, the first step is to pick up the arrival time of the impact signal. During the acquisition stage, by setting the signal voltage threshold value, when the voltage value of the impact signal exceeds the threshold at a certain moment, the time is recorded, and localization is performed through the time difference between the arrival times of different impact signals. In the waveform-based localization method, the partial waveform superposition method is currently the most widely used one. The core content is to perform localization using the similarity of the initial phase information. The algorithm is based on scattering superposition and cross-correlation superposition algorithms. More classic methods include Kirchhoff and coherent superposition methods. The main feature of the partial waveform superposition method is that in addition to the steps of the imaging algorithm for the data, waveform preprocessing must also be carried out. The preprocessing takes the waveform as the input, uses part of the waveform information, and the waveform after shaping is used as the output. The process is similar to the function, and is called the Characteristic Function method (CFs). A classic example of this process is to obtain the envelope of the waveform of an impact signal and use the envelope as the CFs of the input waveform. Superposing the CFs of all waveforms of an event can improve the signal-to-noise ratio while compensating for the diffused energy. The CFs currently used mainly include: a. envelope; b. similarity; c. long-short time window ratio; d. kurtosis; e. multi-channel coherence. The waveform function feature method is a method with mature application and strong anti-interference ability. It is more stable than the method of determining the arrival time based on the threshold value in terms of anti-noise interference, and the computational amount does not increase significantly.

[0052] However, the waveform feature function method still has the following deficiencies: (1) The kurtosis feature function method is applicable to high signal-to-noise ratio data. For cases with severe noise and large range variations, the result stability is poor. (2) The envelope feature function method can obtain relatively stable results. However, in a strong noise background, the waveform differences of the same acoustic emission event on different channels are large, and superposition will cause signal amplitude damage and reduced fidelity. (3) The long-short time window ratio method can provide a positioning result with better accuracy and noise resistance, and is one of the most widely used methods. However, in the case of single-frequency strong noise, there is still a large time error in the judgment of the waveform takeoff point. (4) The acoustic emission signal extraction method based on time-frequency spectrum similarity can provide waveforms with a high signal-to-noise ratio and high time resolution. However, the phase information of the waveform is inaccurate because, under strong background noise conditions, the waveform of the original impact signal is severely interfered, and the phase information is submerged in the noise, and the spectra of the effective signal and the noise signal are aliased in a relatively long time domain range. (5) The multi-channel coherence feature function method performs positioning based on the idea of multi-channel coherent superposition and can form a positioning map. The maximum value can often well indicate the location where the event occurs. It's just that the waveform is affected by random noise or waveform composite effects during propagation, and the relevant superposition forms a large credibility range around the real event location, and the accuracy needs to be improved. The problems faced by the waveform feature function method mainly focus on the fact that the positioning accuracy cannot well meet the requirements. Specifically, when the waveform is recognized or the takeoff moment is determined, there is still a relatively large time error.

[0053] In summary, due to the influence of strong noise interference or waveform distortion, the existing acoustic emission positioning methods have large errors in waveform-based positioning methods. To solve this problem, this application proposes a method for acoustic emission positioning using the local waveform spectrum envelope as a feature function. Specifically, based on the conventional waveform positioning result, first find the time reference point for intercepting the waveform and determine the time window length, and then calculate the spectrum envelope of the waveform within the time window. This measure amplifies the waveform commonality of the same acoustic emission event distributed on different channels, improves the signal-to-noise ratio of the data, and further corrects the error of the coherent superposition positioning algorithm. Compared with the existing methods, this application can eliminate the influence of waveform composite effects and frequency aliasing effects, narrow the error range of the cross-correlation method positioning result, and greatly improve the positioning accuracy. The following will elaborate on this application through specific embodiments.

[0054] Figure 1 It is a flowchart of the acoustic emission positioning method provided by an embodiment of the present invention. As Figure 1 shown, the acoustic emission positioning method provided in this embodiment may include:

[0055] S101. Collect the time-domain waveform data of the acoustic emission events of the observation target on multiple channels through a collection device to obtain the multi-channel time-domain waveform data of the acoustic emission events.

[0056] In this embodiment, the observation system can be designed according to the geometric shape of the observation target. Since the wavelength information of the acoustic emission signal during the indoor test does not affect the design of the observation system, the spatial arrangement of the sensors is relatively flexible. For example, in an alternative embodiment, the acquisition device needs to include at least four acoustic emission receiving sensors that are not in the same plane.

[0057] When using the acquisition device to collect data of acoustic emission events, the acquisition threshold parameter value is usually set above 23 dB to receive the acoustic emission signals from the observation target to the maximum extent. In an alternative embodiment, in order to improve the matching degree between the acquisition threshold value and the observation target, the acquisition threshold value can be determined according to the lithology and size of the core of the observation target.

[0058] S102. Obtain a preliminary positioning result of the acoustic emission event by using a cross-correlation algorithm based on the multi-channel time-domain waveform data of the acoustic emission event.

[0059] In this embodiment, the first arrival time of the acoustic emission event can be automatically picked up by using the cross-correlation algorithm, and the time locking operation is performed. Then, the arrival time difference of different impact signals of the same event is obtained by using the cross-correlation algorithm, and further the preliminary positioning result is obtained.

[0060] That is to say, in an alternative embodiment, obtaining a preliminary positioning result of the acoustic emission event by using a cross-correlation algorithm based on the multi-channel time-domain waveform data of the acoustic emission event may specifically include: determining the arrival time of the impact signal on each channel by using the cross-correlation algorithm according to the multi-channel time-domain waveform data of the acoustic emission event; obtaining the preliminary positioning result of the acoustic emission event according to the arrival time difference of the impact signals of the acoustic emission event on different channels.

[0061] It should be noted that the cross-correlation algorithm can also be integrated in the acquisition device, that is, the acquisition device itself has a positioning function based on the cross-correlation algorithm. Therefore, the preliminary positioning result of the acoustic emission event can be obtained according to the positioning function of the acquisition device itself.

[0062] S103. For the time-domain waveform data of each channel, intercept the time-domain waveform data within a preset time period before and after the arrival time of the impact signal by using a preset window function to obtain multi-channel local time-domain waveform data of the acoustic emission event.

[0063] In this embodiment, the time window width can be set according to the time domain waveform information to intercept the time domain waveform. Specifically, the waveform delay time can be obtained according to the time domain waveform data collected in step S101, and then the time window length is determined according to the waveform delay time, and finally the waveform within a certain time before and after the arrival time is intercepted by using the preset window function. The preset window function in this embodiment can, for example, adopt a Gaussian window function, a Hamming window function, and a trapezoidal window function. It should be noted that since the acquisition threshold value is higher than the zero value, the corresponding time point is not the starting point of the waveform in the strict sense, so it is necessary to take the waveform within a quarter of the time window length forward based on the threshold value corresponding time position. Specifically, the starting position corresponding to the acquisition threshold value can be used as a reference point, and the window length can be determined according to the waveform delay, and the waveform within the first quarter of the time window length of the reference point plus the waveform of the next time window length is used as the selection result to include the real starting position of the waveform. For cores with strong brittleness, due to the small rise time, the window length can be adjusted to one-sixth to one-tenth to include the real starting position of the waveform.

[0064] That is to say, in an optional implementation, a preset window function is used to intercept the time domain waveform data within a preset time length before and after the arrival of the impact signal, which can specifically include: obtaining the waveform delay time according to the multi-channel time domain waveform data of the acoustic emission event, and determining the time window length according to the waveform delay time; taking the starting position corresponding to the acquisition threshold value as the reference point, and using the preset window function to intercept the time domain waveform data within a quarter of the time window length before the reference point and a time window length after the reference point. In this way, it can be ensured that the intercepted local time domain waveform data contains the real starting position of the waveform.

[0065] S104, obtaining a frequency spectrum envelope corresponding to the multi-channel local time-domain waveform data of the acoustic emission event.

[0066] After obtaining the multi-channel local time domain waveform data of the acoustic emission event, the spectrum can be calculated and the spectrum envelope can be extracted. The spectrum of the time domain waveform data of each channel intercepted in step S103 is obtained. The interception of the local waveform is realized in step S103, and the window function used for interception greatly reduces the Gibbs effect in the process of calculating the spectrum, so that a more realistic local waveform frequency characteristic can be obtained. Next, the corresponding spectrum envelope is further calculated. For example, the spectrum envelope can be determined using algorithms in graphic calculation (such as extreme value method, mathematical morphology method, etc.). By extracting the spectrum envelope corresponding to the multi-channel local time domain waveform data of the acoustic emission event, the common information of the waveforms in different channels of the same acoustic emission event is captured, and the commonality between the waveforms distributed in different channels of the same acoustic emission event is amplified, and the commonality is amplified and the heterogeneity is reduced, which helps to improve the positioning accuracy.

[0067] S105. According to the spectral envelope, use the coherent superposition algorithm to correct the preliminary positioning result to obtain the final positioning result of the acoustic emission event.

[0068] Input the spectral envelope corresponding to the multi-channel local time-domain waveform data of the obtained acoustic emission event into the coherent superposition method to obtain a positioning map. Specifically, the spectral envelope obtained in step S104 can be brought into the coherent superposition positioning algorithm to calculate the positioning result, and the goal of correcting the time difference between each channel is achieved during the process. Finally, the positioning accuracy is improved through the cross-correlation algorithm, and the result is generated into a positioning map. The position with the maximum correlation energy in the map is determined as the corrected acoustic emission positioning result. Repeat the above steps S102 to S105 for each time to obtain the corresponding corrected acoustic emission positioning result. That is, in an optional implementation manner, according to the spectral envelope, use the coherent superposition algorithm to correct the preliminary positioning result to obtain the final positioning result of the acoustic emission event, which may specifically include: input the spectral envelope into the coherent superposition algorithm to obtain a positioning map; determine the position with the maximum correlation energy in the positioning map as the final positioning result of the acoustic emission event.

[0069] Bring the spectral envelope information into the coherent superposition algorithm. Since the information of the same acoustic emission event accounts for a relatively high proportion in the envelope, the signal-to-noise ratio is equivalently increased, making the similarity of the waveform spectral envelopes of the same acoustic emission event distributed in different channels reach the highest. The result of the increased similarity is to eliminate the influence brought by phase distortion in the coherent superposition algorithm or the migration algorithm. Finally, the positioning accuracy is improved through the cross-correlation algorithm, and the result is generated into a positioning map.

[0070] The acoustic emission positioning method provided in this embodiment collects the time-domain waveform data of the acoustic emission event of the observation target on multiple channels through a collection device to obtain the multi-channel time-domain waveform data of the acoustic emission event; according to the multi-channel time-domain waveform data of the acoustic emission event, use the cross-correlation algorithm to obtain the preliminary positioning result of the acoustic emission event; for the time-domain waveform data of each channel, use a preset window function to intercept the time-domain waveform data within a preset time period before and after the arrival time of the impact signal to obtain the multi-channel local time-domain waveform data of the acoustic emission event; obtain the spectral envelope corresponding to the multi-channel local time-domain waveform data of the acoustic emission event; according to the spectral envelope, use the coherent superposition algorithm to correct the preliminary positioning result to obtain the final positioning result of the acoustic emission event. Using the local waveform spectral envelope as a feature function amplifies the waveform commonality of the same acoustic emission event distributed in different channels, can overcome the interference of noise, and improve the positioning accuracy.

[0071] The following uses a specific example to further illustrate the acoustic emission localization method based on the local waveform characteristics of signals provided in this application. Specifically, the acoustic emission process data of a rock sample with a diameter of 50 mm and a height of 100 mm is numerically simulated, and the acoustic emission localization results are monitored during the compression experiment. This sample is provided with a crack, as Figure 2 shown. Figure 2 is a radial slice diagram of a two-dimensional rock sample provided in an embodiment of the present invention. As the load continuously increases, an acoustic emission event is generated. Please refer to Figure 3 , Figure 3 is a schematic diagram of the true position of the acoustic emission event and the projection position of the sensor provided in an embodiment of the present invention. As shown by the snowflake-shaped points in Figure 3 , this snowflake-shaped point represents the true position of the acoustic emission event, and the square points on the circle represent the projection positions of the acoustic emission receiving sensors on the slice diagram. The point directly above can be set as the first channel, and rotating clockwise, they are the second to eighth channels in sequence, that is, the data acquisition for this time is 8-channel data acquisition. The propagation process of the acoustic emission signal is as shown in Figure 4 , Figure 4 is a schematic diagram of the wave field snapshot of the acoustic emission signal propagation process provided in an embodiment of the present invention. Figure 4 records the wave field snapshots with a length of 1 ms and recorded every 100 us. The finally acquired acoustic emission waveforms of 8 channels are as shown in Figure 5 , Figure 5 is a schematic diagram of the time-domain waveform of the impact signals received by each channel provided in an embodiment of the present invention. According to the multi-channel time-domain waveform data of the acoustic emission event, the cross-correlation algorithm is used to perform a preliminary localization of the acoustic emission event, and the result is as shown in Figure 6 . Figure 6 is a schematic diagram of the preliminary localization result provided in an embodiment of the present invention. Figure 6 The black circle in it represents the preliminary localization result. It can be clearly seen from the figure that there is a large deviation between the preliminary localization result and the true position of the acoustic emission event. The reason is that the acoustic emission signal is superimposed with the filtering effect of the core during the propagation process. Here, the most prominent is the interference of the crack on the propagation of the acoustic wave signal, and the interference is reflected in the distortion of the acoustic emission waveform, resulting in a large deviation between the localization result and the true position.

[0072] In this example, the main frequency of the impact signal waveform received is 50 kHz. Therefore, the time window length is set to 200 us, and the waveform including one-quarter of the time window length is included forward based on the reference point, and a signal with a length of 250 us is intercepted in total, as shown in Figure 7 , Figure 7 is a schematic diagram of the intercepted local time-domain waveform provided in an embodiment of the present invention. The corresponding spectral envelope is as shown in Figure 8 . Comparing Figure 7 and Figure 8It can be seen that the waveforms of the second and third channels pass through the crack and are greatly interfered, so the waveforms are no longer the same. However, there is a great similarity in the spectral envelopes. Using the spectral envelope as the characteristic function, the goal of amplifying the commonality between waveforms is achieved. Substituting the obtained spectral envelope into the coherent superposition positioning method, the corrected positioning result is obtained. As Figure 9 The position shown by the white circle in

[0073] is the corrected position, which almost coincides with the snowflake-shaped point (the actual position where the acoustic emission event occurs). To sum up, the acoustic emission positioning method based on the local waveform characteristics of the signal provided by this application solves the problems that the existing acoustic emission positioning methods are vulnerable to strong noise interference and have large errors in the waveform-based positioning method when the waveform is distorted. This application locates the acoustic emission event by using the local waveform spectral envelope as the characteristic function. Specifically, first, based on the preliminary positioning result of the conventional cross-correlation algorithm, then find the time reference point for intercepting the waveform and determine the time window length to intercept the waveform, and calculate the spectral envelope of the waveform within the time window. This measure amplifies the commonality of the waveforms of the same acoustic emission event distributed in different channels, improves the signal-to-noise ratio of the data, overcomes the influence of noise interference and the problem of phase distortion, and further corrects the error of the coherent superposition positioning algorithm. Compared with the conventional method, the accuracy is greatly improved.

[0074] Figure 10 This is a schematic structural diagram of an acoustic emission positioning device provided by an embodiment of the present invention. As Figure 10 shown, this embodiment provides an acoustic emission positioning device 40, which may include: an acquisition module 401, a processing module 402, an interception module 403, an acquisition module 404, and a correction module 405.

[0075] The acquisition module 401 is configured to collect the time-domain waveform data of the acoustic emission events of the observation target on multiple channels through an acquisition device, and obtain the multi-channel time-domain waveform data of the acoustic emission events;

[0076] The processing module 402 is configured to obtain the preliminary positioning result of the acoustic emission event by using the cross-correlation algorithm according to the multi-channel time-domain waveform data of the acoustic emission event;

[0077] The interception module 403 is configured to, for the time-domain waveform data of each channel, intercept the time-domain waveform data within a preset duration before and after the arrival time of the impact signal by using a preset window function, and obtain the multi-channel local time-domain waveform data of the acoustic emission event;

[0078] The acquisition module 404 is configured to obtain the spectral envelope corresponding to the multi-channel local time-domain waveform data of the acoustic emission event;

[0079] The correction module 405 is configured to correct the preliminary positioning result according to the spectral envelope by using the coherent superposition algorithm to obtain the final positioning result of the acoustic emission event.

[0080] The device of this embodiment can be used to execute Figure 1 the technical solution of the method embodiment shown. The implementation principle and technical effect are similar, and will not be elaborated here.

[0081] In an alternative embodiment, the processing module 402 is configured to obtain the preliminary positioning result of the acoustic emission event according to the multi-channel time-domain waveform data of the acoustic emission event by using the cross-correlation algorithm. Specifically, it may include:

[0082] Determine the arrival time of the impact signal on each channel according to the multi-channel time-domain waveform data of the acoustic emission event by using the cross-correlation algorithm;

[0083] Obtain the preliminary positioning result of the acoustic emission event according to the arrival time difference of the impact signals of the acoustic emission event on different channels.

[0084] In an alternative embodiment, the truncation module 403 is configured to truncate the time-domain waveform data within a preset time period before and after the arrival time of the impact signal by using a preset window function. Specifically, it may include:

[0085] Obtain the waveform delay time according to the multi-channel time-domain waveform data of the acoustic emission event, and determine the time window length according to the waveform delay time;

[0086] Take the starting position corresponding to the acquisition threshold value as the reference point, and truncate the time-domain waveform data within the first quarter of the time window length before the reference point and within one time window length after the reference point by using a preset window function.

[0087] In an alternative embodiment, the acquisition threshold value is determined according to the lithology and size of the core.

[0088] In an alternative embodiment, the correction module 405 is configured to correct the preliminary positioning result according to the spectral envelope by using the coherent superposition algorithm to obtain the final positioning result of the acoustic emission event. Specifically, it may include:

[0089] Input the spectral envelope into the coherent superposition algorithm to obtain the positioning map;

[0090] Determine the position with the maximum correlation energy in the positioning map as the final positioning result of the acoustic emission event.

[0091] In an alternative embodiment, the preset window function includes a Gaussian window function, a Hamming window function, and a trapezoidal window function.

[0092] In an alternative embodiment, the acquisition device includes at least four acoustic emission receiving sensors not in the same plane.

[0093] An embodiment of the present invention further provides an electronic device. Please refer to Figure 11 as shown. The embodiments of the present invention are only described Figure 11 by way of example and do not mean that the present invention is limited thereto. Figure 11 It is a schematic structural diagram of an electronic device provided by an embodiment of the present invention. As Figure 11 shown, the electronic device 60 provided in this embodiment may include: a memory 601, a processor 602, and a bus 603. Among them, the bus 603 is used to realize the connection between various components.

[0094] A computer program is stored in the memory 601, and when the computer program is executed by the processor 602, the technical solutions of any of the above method embodiments can be realized.

[0095] Among them, the memory 601 and the processor 602 are directly or indirectly electrically connected to realize data transmission or interaction. For example, these components can be electrically connected to each other through one or more communication buses or signal lines, such as being connected through the bus 603. A computer program for implementing the acoustic emission positioning method is stored in the memory 601, including at least one software function module that can be stored in the memory 601 in the form of software or firmware. The processor 602 executes various functional applications and data processing by running the software programs and modules stored in the memory 601.

[0096] The memory 601 may be, but is not limited to, a random access memory (Random Access Memory, abbreviated as RAM), a read-only memory (Read Only Memory, abbreviated as ROM), a programmable read-only memory (Programmable Read-Only Memory, abbreviated as PROM), an erasable programmable read-only memory (Erasable Programmable Read-Only Memory, abbreviated as EPROM), an electrically erasable programmable read-only memory (Electric Erasable Programmable Read-Only Memory, abbreviated as EEPROM), etc. Among them, the memory 601 is used to store programs, and the processor 602 executes the programs after receiving execution instructions. Further, the software programs and modules in the above memory 601 may further include an operating system, which may include various software components and / or drivers for managing system tasks (such as memory management, storage device control, power management, etc.), and may communicate with various hardware or software components to provide a running environment for other software components.

[0097] The processor 602 may be an integrated circuit chip with the ability to process signals. The above-mentioned processor 602 may be a general-purpose processor, including a Central Processing Unit (CPU), a Network Processor (NP), etc. It can implement or execute the various methods, steps, and logic block diagrams disclosed in the embodiments of the present invention. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc. It can be understood that Figure 11 The structure of is only schematic, and it may also include more or fewer components than those shown in Figure 11 or have a different configuration from that shown in Figure 11 . Figure 11 Each component shown in can be implemented by hardware and / or software.

[0098] The embodiments of the present invention also provide a computer-readable storage medium, on which a computer program is stored. The computer program is executed by a processor to implement the technical solutions of any one of the above method embodiments.

[0099] Each embodiment in this disclosure is described in a progressive manner. For the same or similar parts among the embodiments, reference can be made to each other. The key point of each embodiment is to illustrate the differences from other embodiments.

[0100] The protection scope of this disclosure is not limited to the above embodiments. Obviously, those skilled in the art can make various changes and deformations to this disclosure without departing from the scope and spirit of this disclosure. If these changes and deformations belong to the scope of the claims of this disclosure and their equivalent technologies, the intention of this disclosure also includes these changes and deformations.

Claims

1. An acoustic emission location method, characterized in that, Comprising: Collecting time-domain waveform data of acoustic emission events of an observation target on multiple channels through a collecting device to obtain multi-channel time-domain waveform data of the acoustic emission events; According to the multi-channel time-domain waveform data of the acoustic emission events, using a cross-correlation algorithm to obtain a preliminary positioning result of the acoustic emission events; For the time-domain waveform data of each channel, using a preset window function to intercept the time-domain waveform data within a preset time length before and after the arrival time of the impact signal to obtain multi-channel local time-domain waveform data of the acoustic emission events; Obtaining a spectral envelope corresponding to the multi-channel local time-domain waveform data of the acoustic emission events; According to the spectral envelope, using a coherent superposition algorithm to correct the preliminary positioning result to obtain a final positioning result of the acoustic emission events.

2. The method according to claim 1, characterized in that, The step of using a cross-correlation algorithm to obtain a preliminary positioning result of the acoustic emission events according to the multi-channel time-domain waveform data of the acoustic emission events includes: According to the multi-channel time-domain waveform data of the acoustic emission events, using a cross-correlation algorithm to determine the arrival time of the impact signal on each channel; According to the arrival time difference of the impact signal of the acoustic emission events on different channels, obtaining a preliminary positioning result of the acoustic emission events.

3. The method according to claim 1, wherein The step of using a preset window function to intercept the time-domain waveform data within a preset time length before and after the arrival time of the impact signal includes: Obtaining a waveform delay time according to the multi-channel time-domain waveform data of the acoustic emission events, and determining a time window length according to the waveform delay time; Taking the takeoff position corresponding to the acquisition threshold value as a reference point, and using a preset window function to intercept the time-domain waveform data within a quarter of the time window length before the reference point and within one time window length after the reference point.

4. The method according to claim 3, characterized in that, The acquisition threshold value is determined according to the lithology and size of the core.

5. The method according to claim 1, wherein The step of using a coherent superposition algorithm to correct the preliminary positioning result according to the spectral envelope to obtain a final positioning result of the acoustic emission events includes: Inputting the spectral envelope into the coherent superposition algorithm to obtain a positioning map; Determining the position with the maximum correlation energy in the positioning map as the final positioning result of the acoustic emission events.

6. The method according to claim 1, wherein The preset window function includes a Gaussian window function, a Hamming window function, and a trapezoidal window function.

7. The method according to any one of claims 1 to 6, characterized in that The collecting device includes at least four acoustic emission receiving sensors not in the same plane.

8. An acoustic emission positioning device, characterized in that, Comprising: A collecting module, configured to collect time-domain waveform data of acoustic emission events of an observation target on multiple channels through a collecting device to obtain multi-channel time-domain waveform data of the acoustic emission events; A processing module, configured to obtain a preliminary positioning result of the acoustic emission events by using a cross-correlation algorithm according to the multi-channel time-domain waveform data of the acoustic emission events; An intercepting module, configured to, for the time-domain waveform data of each channel, use a preset window function to intercept the time-domain waveform data within a preset time length before and after the arrival time of the impact signal to obtain multi-channel local time-domain waveform data of the acoustic emission events; An obtaining module, configured to obtain a spectral envelope corresponding to the multi-channel local time-domain waveform data of the acoustic emission events; A correction module, configured to correct the preliminary positioning result according to the spectral envelope by using a coherent superposition algorithm to obtain the final positioning result of the acoustic emission event.

9. An electronic device, characterized in that, It includes: At least one processor and a memory; The memory stores computer-executable instructions; The at least one processor executes the computer-executable instructions stored in the memory, so that the at least one processor executes the acoustic emission positioning method according to any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, Computer-executable instructions are stored in the computer-readable storage medium, and when the computer-executable instructions are executed by a processor, they are used to implement the acoustic emission positioning method according to any one of claims 1-7.

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