Multi-point Acoustic Emission Location Method for Annular Structure Based on Energy Integration

Abstract

The present invention belongs to the field of acoustic emission technology, and particularly relates to a multi-point acoustic emission localization method for a ring structure based on energy integration, comprising the following steps: collecting the acoustic emission signals of all sensors located on the surface of the ring structure at a fixed frequency; converting the acoustic emission signals of each sensor into frequency domain signals, and constructing an energy integration and phase model based on a specified frequency range; based on the spatial layout positions of each sensor and the acoustic wave velocity, combining the energy integration and phase model, and using a multi-point localization algorithm to solve the position of the impact point; determining the projection point corresponding to the impact point on the surface of the ring structure, and constructing a confidence ellipsoid based on the projection point; calculating the intersection line between the confidence ellipsoid and the ring structure to define the impact area. It can significantly improve the localization accuracy of the sound source position, and more intuitively and reasonably reflect the relationship between the uncertainty of the localization result and the geometric shape of the ring structure.

Description

Technical Field

[0001] The present invention belongs to the field of acoustic emission technology, and particularly relates to a multi-point acoustic emission positioning method for a ring structure based on energy integration. Background Art

[0002] Acoustic Emission Technique (AET) is a non-destructive detection and evaluation method, which is widely used in the field of Structural Health Monitoring (SHM). This technique is based on the detection and analysis of transient elastic waves (i.e., acoustic emission signals) released during the damage processes such as the initiation, propagation, and fracture of internal microcracks in materials under stress. Acoustic emission signals carry important information about the location, type, and severity of structural damage. By receiving and processing these signals through a suitable sensor array, real-time monitoring and evaluation of the structural state can be achieved.

[0003] Although acoustic emission technology shows great potential in structural health monitoring, the current acoustic emission positioning methods still face a series of technical challenges. Specifically, it is reflected in that single impact point positioning cannot comprehensively reflect the structural state and it is difficult to find out the weak areas of the structure; sensors may receive signals from different sources simultaneously, making it difficult to accurately classify specific impact sources; in a ring structure, sound waves may propagate cyclically along the edge, and even if appropriate criteria are set, a single impact may still be recorded multiple times; in practical applications, it is often necessary to locate multiple impact points simultaneously, and existing methods are difficult to effectively handle; traditional methods do not consider the frequency characteristics of signals enough, which may lead to low signal-to-noise ratio and low positioning accuracy. Summary of the Invention

[0004] The present invention aims to provide a multi-point acoustic emission positioning method for a ring structure based on energy integration. By analyzing the energy distribution in a specific frequency range through the acoustic emission signals collected by multiple sensors, the positioning accuracy of the sound source position can be significantly improved, multi-point positioning is performed to solve the impact point position, and then a confidence ellipsoid is constructed. By comparing the confidence ellipsoid with the ring structure, the possible impact area on the entire surface of the ring structure is determined. This method is more intuitive and reasonable, can directly reflect the relationship between the uncertainty of the positioning result and the geometric shape of the ring structure, simplifies the judgment process, improves the applicability and interpretability of the method, and has certain expandability.

[0005] A multi-point acoustic emission positioning method for a ring structure based on energy integration includes the following steps:

[0006] Collect the acoustic emission signals of all sensors located on the surface of the ring structure at a fixed frequency;

[0007] Convert the acoustic emission signals of each sensor into frequency-domain signals, and construct an energy integral and phase model based on a specified frequency range;

[0008] Based on the spatial layout positions of each sensor and the acoustic wave velocity, combined with the energy integral and phase model, use a multi-point positioning algorithm to solve the position of the impact point;

[0009] Determine the projection points corresponding to the impact point position on the surface of the annular structure, and construct a confidence ellipsoid based on the projection points;

[0010] Calculate the intersection line of the confidence ellipsoid and the annular structure to define the impact area.

[0011] By analyzing the energy distribution in a specific frequency range through the acoustic emission signals collected by multiple sensors, the positioning accuracy of the sound source position can be significantly improved. Perform multi-point positioning to solve the position of the impact point, and then construct a confidence ellipsoid. By comparing the confidence ellipsoid with the annular structure, determine the possible impact area for the entire surface of the annular structure. This method is more intuitive and reasonable, can directly reflect the relationship between the uncertainty of the positioning result and the geometric shape of the annular structure, simplifies the judgment process, improves the applicability and interpretability of the method, and has certain expandability.

[0012] Furthermore, at least three sensors are evenly installed on the surface of the annular structure;

[0013] The fixed-frequency acquisition of the acoustic emission signals of all sensors located on the surface of the annular structure includes:

[0014] Set a time window, and acquire the acoustic emission signals of all sensors at a fixed frequency and synchronously.

[0015] Furthermore, the conversion of the acoustic emission signals of each sensor into frequency-domain signals and the construction of an energy integral and phase model based on a specified frequency range include:

[0016] Perform a fast Fourier transform on the acoustic emission signals of each sensor to obtain frequency-domain signals;

[0017] Within the specified frequency range, obtain the peak frequencies of all frequency-domain signals;

[0018] Based on the peak frequencies, combined with a preset offset coefficient, calculate the frequency offset;

[0019] Within the frequency range calculated based on the frequency peak and frequency offset, construct an energy integral and phase equation.

[0020] Furthermore, before performing a fast Fourier transform on the acoustic emission signal of each sensor, it also includes:

[0021] Preprocess and segment the collected acoustic emission signals;

[0022] The preprocessing includes denoising by using the wavelet transform method; the segmentation includes using the threshold method to segment the preprocessed acoustic emission signal into multiple impact events, which are used as the acoustic emission signals for performing the fast Fourier transform.

[0023] Further, the method for solving the position of the impact point by using the multi-point positioning algorithm based on the spatial layout positions of the sensors and the acoustic wave velocity, in combination with the energy integration and phase model, includes:

[0024] Based on each impact event within the time window, preset the position of the impact point;

[0025] According to the spatial layout positions of the sensors and the acoustic wave velocity, and in combination with the energy integration and phase model, construct the acoustic wave energy and phase models of the sensors;

[0026] The method for solving the position of the impact point by using the multi-point positioning algorithm includes, based on the preset position of the impact point, respectively obtaining the predicted data and observed data of the acoustic wave energy and phase models corresponding to each sensor, and defining an objective function to measure the difference between the model predicted data and the observed data, and iteratively solving the position of the impact point and the model parameters.

[0027] Further, the method for determining the projection point corresponding to the impact point on the surface of the annular structure and constructing a confidence ellipsoid based on the projection point includes:

[0028] Based on the position of the impact point, determine its projection point on the surface of the annular structure;

[0029] Obtain the covariance matrix according to the multi-point positioning algorithm, and construct a confidence ellipsoid based on the projection point.

[0030] Further, the method for calculating the intersection line of the confidence ellipsoid and the annular structure to define the impact area includes:

[0031] When the confidence ellipsoid intersects with the surface of the annular structure, the intersection line and the corresponding part of the surface of the annular structure are defined as the impact area;

[0032] When the confidence ellipsoid intersects with the plane where the axial edge of the annular structure is located, the area where the intersection line is located is defined as the impact area;

[0033] When the confidence ellipsoid does not intersect with both the surface of the annular structure and the plane where the axial edge is located, but intersects with the extended plane where the surface of the annular structure is located, the intersection line of the confidence ellipsoid and the extended plane is defined as the impact area.

[0034] A system for a multi-point positioning method of acoustic emission of an annular structure based on energy integration, includes:

[0035] The first module is used to collect the acoustic emission signals of all sensors located on the surface of the annular structure at a fixed frequency;

[0036] The second module is used to convert the acoustic emission signals of each sensor into frequency-domain signals and construct an energy integral and phase model based on a specified frequency range;

[0037] The third module is used to solve the position of the impact point by using a multi-point positioning algorithm based on the spatial layout positions of each sensor and the acoustic wave velocity, in combination with the energy integral and phase model;

[0038] The fourth module is used to determine the projection point corresponding to the impact point on the surface of the annular structure and construct a confidence ellipsoid based on the projection point;

[0039] The fifth module is used to calculate the intersection line between the confidence ellipsoid and the annular structure to define the impact area.

[0040] An electronic device, the electronic device includes a memory and a processor, the memory stores a computer program, and when the processor executes the computer program, the above-mentioned method is implemented.

[0041] A computer-readable storage medium, the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the above-mentioned method is implemented.

[0042] The beneficial effects of the present invention are:

[0043] By analyzing the energy distribution in a specific frequency range through the acoustic emission signals of multiple sensors collected by the present invention, the positioning accuracy of the sound source position can be significantly improved, multi-point positioning is performed to solve the position of the impact point, and then a confidence ellipsoid is constructed. By comparing the confidence ellipsoid with the annular structure, the possible impact area for the entire surface of the annular structure is determined. This method is more intuitive and reasonable, can directly reflect the relationship between the uncertainty of the positioning result and the geometric shape of the annular structure, and at the same time provides a clear judgment basis for the extended analysis of the plane where the annular structure is located, simplifies the judgment process, improves the applicability and interpretability of the method, and has certain expandability. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 is a flowchart of the present invention;

[0045] Figure 2 is a schematic structural diagram of the present invention;

[0046] Figure 3 is a schematic structural diagram of a computer device. DETAILED DESCRIPTION OF THE INVENTION

[0047] Next, in combination with the accompanying drawings in the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0048] It should be noted that the following describes various aspects of embodiments within the scope of the appended claims. It should be apparent that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and / or function described herein is illustrative only. Based on this disclosure, those skilled in the art should understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects described herein can be used to implement a device and / or practice a method. Additionally, this device and / or this method can be implemented using other structures and / or functionality in addition to one or more of the aspects described herein.

[0049] In addition, in the following description, specific details are provided to facilitate a thorough understanding of the examples. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0050] Embodiment 1

[0051] Figure 1 Shown is a multi - point acoustic emission location method for a ring structure based on energy integration. By analyzing the energy distribution in a specific frequency range from the acoustic emission signals collected by multiple sensors, the location accuracy of the sound source position can be significantly improved. Multi - point location is used to solve for the impact point position, and then a confidence ellipsoid is constructed. By comparing the confidence ellipsoid with the ring structure, the possible impact area for the entire surface of the ring structure is determined. This method is more intuitive and reasonable, can directly reflect the relationship between the uncertainty of the location result and the geometric shape of the ring structure, simplifies the judgment process, improves the applicability and interpretability of the method, and has a certain degree of expandability. Specifically, it includes the following steps:

[0052] S1: Collect the acoustic emission signals of all sensors located on the surface of the ring structure at a fixed frequency;

[0053] Among them, at least three sensors are evenly installed on the surface of the ring structure; in this embodiment, the number of sensors is three, and the positions of each sensor are represented by three - dimensional coordinates; specifically including:

[0054] The first sensor, whose coordinate position on the surface of the ring structure is A(r·cos(0), r·sin(0), 0);

[0055] A second sensor, whose coordinate position on the surface of the annular structure is

[0056] A third sensor, whose coordinate position on the surface of the annular structure is

[0057] In the formula, r represents the radius of the annular structure.

[0058] It should be noted that in the actual use process, the signal acquisition accuracy can be improved by increasing the number of sensors.

[0059] The fixed-frequency acquisition of the acoustic emission signals of all sensors located on the surface of the annular structure includes:

[0060] S11: Set a time window T, and acquire the acoustic emission signals of all sensors at a fixed frequency and synchronously.

[0061] In this embodiment, the actual sampling frequency is at least twice the expected highest frequency; when the expected highest signal frequency is 150 kHz, the actual sampling frequency fs > 300 kHz.

[0062] It should be noted that it can be set as continuous time windows that are connected, or it can also be set as continuous time windows that have intersections.

[0063] Based on the acquired acoustic emission signal of each sensor, a preprocessing process and a segmentation process are performed on it. The preprocessing process includes denoising and noise reduction processing using the wavelet transform method; the segmentation process includes using the threshold method to segment the preprocessed acoustic emission signal into multiple impact events, and using them as the acoustic emission signals for performing the fast Fourier transform.

[0064] S2: Convert the acoustic emission signals of each sensor into frequency-domain signals, and construct an energy integral and a phase model based on the specified frequency range;

[0065] S21: Perform a fast Fourier transform on the acoustic emission signal of each sensor based on each impact event to obtain a frequency-domain signal;

[0066] Among them, the expression of the fast Fourier transform FFT is:

[0067]

[0068] In the formula, X(k) represents the frequency-domain signal, k represents the frequency-domain signal index; x(n) represents the time-domain signal; n represents the time-domain

[0069] sampling point, n = 0, 1, 2,..., N - 1, N represents the number of sampling points, that is, the signal length; j represents the imaginary unit;

[0070] S22: Obtain the peak frequencies of all frequency-domain signals within the specified frequency range;

[0071] Among them, the expression for the peak frequency fp in the range of 100 - 150 kHz is:

[0072] fp = argmax(|X(k)|);

[0073] In the formula, fp represents the peak frequency; argmax() represents the maximum extraction function; k represents the frequency-domain index; a represents the minimum value of the selected frequency range, and b represents the maximum value of the selected frequency range.

[0074] When the specified frequency range is set to 100 - 150 kHz,

[0075] S23: Calculate the frequency offset based on the peak frequency and in combination with a preset offset coefficient;

[0076] Among them, the expression for the frequency offset is:

[0077] F_shift = α·fp;

[0078] In the formula, F_shift represents the frequency offset; α represents the offset coefficient, which can take 0.00001 or be selected according to the actual situation.

[0079] S24: Construct an energy integral and a phase equation within the frequency range calculated based on the frequency peak and the frequency offset.

[0080] Based on the peak frequency value and the frequency offset value, determine the frequency range as [fp - F, fp + F_shift].

[0081] Based on the obtained frequency range, the expression for the energy integral is:

[0082]

[0083] In the formula, E represents the energy integral;

[0084] Based on the obtained frequency range, the expression for the phase information is:

[0085]

[0086] In the formula, θ represents the phase.

[0087] S3: Based on the spatial layout positions of each sensor and the acoustic wave velocity, in combination with the energy integral and the phase model, use a multi-point positioning algorithm to solve for the position of the impact point;

[0088] S31: Set the impact point position P(x, y, z) based on each impact event within the time window T;

[0089] S32: Construct the acoustic wave energy and phase models of each sensor according to the spatial layout positions of the sensors and the acoustic wave velocity, and in combination with energy integration and phase models;

[0090] Among them, the expression of the acoustic wave energy and phase models of each sensor is:

[0091]

[0092] In the formula, E i represents the acoustic wave energy of the i-th sensor; K represents a constant related to the sound source; P represents the preset impact point position; σ is the attenuation coefficient; P is the impact point position; S i represents the position of the i-th sensor; θ i represents the phase of the i-th sensor

[0093] ; c represents the sound velocity of the medium; θ 0 represents the initial phase;

[0094] S33: Use the multi-point positioning algorithm to solve the position of the impact point, including respectively obtaining the predicted data and observed data of the acoustic wave energy and phase models corresponding to each sensor based on the preset impact point position P, and iteratively solving the impact point position P

[0095] and the model parameters;

[0096] In this embodiment, the multi-point positioning algorithm selects to use the nonlinear least squares method (such as the Levenberg-Marquardt algorithm), and transforms the fitting problem into a problem of minimizing the objective function to measure the difference between the model predicted data and the observed data, and then solves the impact point position P and estimates the parameters. The constructed objective function F(P, K, σ, θ 0 ) has the following expression:

[0097]

[0098] In the formula, F represents the objective function; E i_measured represents the actual measured value of the acoustic wave energy of the i-th sensor, that is, the energy integral value; E i_calculated represents the theoretical measured value of the acoustic wave energy of the i-th sensor, that is, the acoustic wave energy value; represents the standard deviation of the acoustic wave energy of the i-th sensor; θ i_measured represents the actual measured value of the phase of the i-th sensor, that is, the phase value obtained through the phase equation; θ i_calculated represents the theoretical measured value of the phase of the i-th sensor, that is, the phase value obtained through the acoustic wave energy and phase models; Represents the standard deviation of the phase of the i-th sensor.

[0099] Among them, the expression of the energy integration corresponding to the i-th sensor is:

[0100]

[0101] Based on the i-th sensor, considering model correction, the expressions of the acoustic wave energy and phase model are:

[0102]

[0103] In the formula, H(k) represents the frequency response function;

[0104] Based on the actual measured value of the phase of the i-th sensor, that is, the expression of the phase value obtained through the phase equation is:

[0105]

[0106] Based on the i-th sensor, considering model correction, the theoretical measured value of the phase is obtained, that is, the expression of the phase value obtained through the acoustic wave energy and phase

[0107] phase model is:

[0108]

[0109] It should be noted that the integral can be discretized into the sum of a finite number of frequency sampling points for simplified calculation.

[0110] Based on the defined objective function F(P, K, σ, θ 0 ), calculate the acoustic wave energy and phase prediction data of each sensor according to the acoustic wave energy and phase model, and combine and compare them with the actual observation data to calculate the objective function value. Then, update the objective function parameters to minimize the objective function, and iterate until the convergence condition is met, and then obtain the impact point position

[0111] P, as well as the parameter values of the constant K, attenuation coefficient σ, and initial phase θ 0 .

[0112] S4: Determine the projection point corresponding to the impact point position P on the surface of the annular structure, and construct a confidence ellipsoid based on the projection point;

[0113] S41: Based on the impact point position P, determine its projection point P ′ ;

[0114] S42: Obtain the covariance matrix according to the multi-point positioning algorithm, and construct a confidence ellipsoid based on the projection point P ′ .

[0115] In this embodiment, when using the multi-point positioning algorithm, that is, selecting the non-linear least squares method for iterative solution, the Jacobian matrix approximation is constructed by the partial derivatives of the objective function with respect to each parameter to iteratively update the objective function parameters, and the covariance matrix is obtained to describe the deviation degree between the objective function parameters. Specifically, it includes:

[0116] S421: Based on the objective function F(P(x, y, z), K, σ, θ

[0117] )), take the partial derivative with respect to each parameter to construct the Jacobian matrix; 0 )

[0118] Among them, the expression of the Jacobian matrix is:

[0119]

[0120] In the formula, J represents the Jacobian matrix;

[0121] For each sensor of each impact event, the construction of its Jacobian matrix includes:

[0122]

[0123] In practical applications, the approximation of the Jacobian matrix can be constructed by numerical methods (such as the central difference method).

[0124] S422: Based on the values obtained from the acoustic wave energy and phase models of each sensor, combined with the attenuation coefficient σ, construct the weight matrix W;

[0125] Among them, the expression for constructing the weight matrix W using the reciprocal square of the measurement error is:

[0126]

[0127] In the formula, W represents the weight matrix; diag() represents extracting the diagonal matrix.

[0128] S423: Based on the Jacobian matrix and the weight matrix, construct the covariance matrix;

[0129] Among them, the expression of the covariance matrix is:

[0130] ∑=(J T ·W·J) -1

[0131] In the formula, ∑ represents the covariance matrix; J T represents the transpose of the Jacobian matrix.

[0132] Based on the projection point P ′When constructing the confidence ellipsoid, it is constructed according to the 95% confidence interval, and the expression of the confidence ellipsoid is:

[0133] (x - x 0 ) T ·∑ -1 ·(x - x 0 ) = χ 2 (3, 0.95);

[0134] In the formula, x 0 represents the position of the estimated impact point; ∑ represents the covariance matrix; χ 2 (3, 0.95) represents the 95% quantile of the chi-square distribution with 3 degrees of freedom.

[0135] S5: Calculate the intersection line of the confidence ellipsoid and the annular structure to define the impact area.

[0136] When calculating the intersection line of the confidence ellipsoid and the annular structure, it is necessary to compare and judge the intersection relationship between the confidence ellipsoid and the annular structure, and then define the impact area. That is:

[0137] S51: When the confidence ellipsoid intersects with the surface of the annular structure, the intersection line and the corresponding part of the annular structure surface are defined as the impact area;

[0138] Among them, the equation of the annular structure surface is:

[0139] x 2 + y 2 = R 2 .

[0140] In this embodiment, a numerical calculation method (such as the Monte Carlo method) is used to compare and judge the intersection of the confidence ellipsoid and the annular structure surface. The intersection line formed by the intersection of the confidence ellipsoid and the annular structure surface is a closed curve, and the closed curve is arc-shaped or other shapes.

[0141] S52: When the confidence ellipsoid intersects with the plane where the axial edge of the annular structure is located, the area where the intersection line is located is defined as the impact area;

[0142] Among them, the plane equation defining the plane where the axial edge of the annular structure is located is:

[0143]

[0144] In the formula, H represents the height of the annular structure.

[0145] S53: When the confidence ellipsoid does not intersect with both the surface of the annular structure and the plane where the axial edge is located, but intersects with the extended plane where the surface of the annular structure is located, the intersection line of the confidence ellipsoid and the extended plane is defined as the impact area.

[0146] It should be noted that the extended plane is adjacent to the plane where the annular structure surface or the axial edge is located in the spatial position. The comparison and judgment of the extended plane are based on a conservative estimate of the uncertainty of the impact point position, aiming to ensure that the impact area can cover all possible positions.

[0147] Embodiment 2

[0148] Based on the same technical concept, as Figure 2 shown, an annular structure acoustic emission multi-point positioning system based on energy integration is provided in an embodiment of the present application, including a first module, a second module, a third module, a fourth module, and a fifth module.

[0149] Specifically, the first module is used to collect the acoustic emission signals of all sensors located on the surface of the annular structure at a fixed frequency;

[0150] Specifically, the second module is used to convert the acoustic emission signals of each sensor into frequency-domain signals and construct an energy integration and phase model based on a specified frequency range;

[0151] Specifically, the third module is used to solve the position of the impact point by using a multi-point positioning algorithm based on the spatial layout positions of each sensor and the sound wave velocity, in combination with the energy integration and phase model;

[0152] Specifically, the fourth module is used to determine the projection point corresponding to the impact point on the surface of the annular structure and construct a confidence ellipsoid based on the projection point;

[0153] Specifically, the fifth module is used to calculate the intersection line of the confidence ellipsoid and the annular structure to define the impact area.

[0154] Embodiment 3

[0155] Based on the same technical concept, an embodiment of the present application also provides a computer device, including a memory 1 and a processor 2, as Figure 3 shown, the memory 1 stores a computer program, and when the processor 2 executes the computer program, the method described in any one of the above is implemented.

[0156] Among them, the memory 1 at least includes one type of readable storage medium, and the readable storage medium includes flash memory, hard disk, multimedia card, card-type memory (such as SD or DX memory, etc.), magnetic memory, magnetic disk, optical disc, etc. In some embodiments, the memory 1 can be an internal storage unit of the acoustic emission multi-point positioning system with an energy-integrated ring structure, such as a hard disk. In other embodiments, the memory 1 can also be an external storage device of the acoustic emission multi-point positioning system with an energy-integrated ring structure, such as a plug-in hard disk, Smart Media Card (SMC), Secure Digital (SD) card, Flash Card, etc. Further, the memory 1 can also include both an internal storage unit and an external storage device of the acoustic emission multi-point positioning system with an energy-integrated ring structure. The memory 1 can not only be used to store application software installed in the acoustic emission multi-point positioning system with an energy-integrated ring structure and various types of data, such as the code of the acoustic emission multi-point positioning system program, etc., but also be used to temporarily store data that has been output or will be output.

[0157] In some embodiments, the processor 2 can be a central processing unit (CPU), controller, microcontroller, microprocessor or other data processing chip, which is used to run the program code stored in the memory 1 or process data, such as executing the acoustic emission multi-point positioning system program, etc.

[0158] The disclosed embodiments of the present invention also provide a computer-readable storage medium, on which a computer program is stored, and when the computer program is run by a processor, it executes the steps of the method described in the above method embodiments. Among them, the storage medium can be a volatile or non-volatile computer-readable storage medium.

[0159] The computer program product of the application page content refreshing method provided by the disclosed embodiments of the present invention includes a computer-readable storage medium storing program code, and the instructions included in the program code can be used to execute the steps of the method described in the above method embodiments. For details, please refer to the above method embodiments and will not be elaborated here.

[0160] The disclosed embodiments of the present invention also provide a computer program which, when executed by a processor, implements any of the methods in the foregoing embodiments. The computer program product can be specifically implemented in a manner of hardware, software, or a combination thereof. In an alternative embodiment, the computer program product is specifically embodied as a computer storage medium. In another alternative embodiment, the computer program product is specifically embodied as a software product, such as a Software Development Kit (SDK), etc.

[0161] It can be understood that the same or similar parts in the above embodiments can be referred to each other, and the content not described in detail in some embodiments can be seen in the same or similar content in other embodiments.

[0162] It should be noted that in the description of the present invention, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, in the description of the present invention, unless otherwise specified, the meaning of "a plurality of" refers to at least two.

[0163] Any process or method description shown in a flowchart or described in other ways herein can be understood as representing a module, segment, or part of code including one or more executable instructions for implementing a specific logical function or process. The scope of the preferred embodiments of the present invention includes additional implementations, where functions can be executed in a substantially simultaneous manner or in a reverse order according to the involved functions, rather than in the order shown or discussed, which should be understood by those skilled in the technical field to which the embodiments of the present invention belong.

[0164] It should be understood that each part of the present invention can be implemented by hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, any one or a combination of the following well-known technologies in the art can be used: discrete logic circuits with logic gate circuits for implementing logical functions on data signals, application-specific integrated circuits with appropriate combinational logic gate circuits, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0165] Those of ordinary skill in the art of the present technology can understand that all or part of the steps carried by the methods in the above embodiments can be completed by instructing relevant hardware through a program. The program can be stored in a computer-readable storage medium. When the program is executed, it includes one or a combination of the steps of the method embodiments.

[0166] In addition, each functional unit in various embodiments of the present invention may be integrated into one processing module, may exist physically alone for each unit, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. When the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0167] The above-mentioned storage medium may be a read-only memory, a magnetic disk, an optical disc, etc.

[0168] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples.

[0169] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A multi-point positioning method for acoustic emission of a ring structure based on energy integration, characterized in that: The steps include: Acquisition of acoustic emission signals from all sensors located on the surface of the annular structure at a fixed frequency; The acoustic emission signal of each sensor is converted into a frequency domain signal, the frequency peak of all frequency domain signals is obtained within a specified frequency range, and the frequency offset is calculated based on the frequency peak and the preset offset coefficient, and the energy integration and phase model is constructed within the frequency range obtained by combining the frequency peak and the frequency offset calculation; Based on the spatial layout of each sensor and the speed of the sound wave, combined with the energy integration and phase model, a multi-point positioning algorithm is used to solve the location of the impact point; Determine the projection point corresponding to the surface of the annular structure according to the position of the impact point, and construct a confidence ellipsoid based on the projection point; The intersection line of the confidence ellipsoid and the annulus is calculated to define the impact region.

2. The method for multi-point positioning of annular structure acoustic emission based on energy integration according to claim 1 is characterized in that: At least three sensors are evenly installed on the surface of the annular structure; The fixed-frequency acquisition of acoustic emission signals of all sensors located on the surface of the annular structure includes: Set the time window, set the frequency and synchronously collect the acoustic emission signals of all sensors.

3. The method for multi-point positioning of annular structure acoustic emission based on energy integration according to claim 1 is characterized in that: The method of converting the acoustic emission signal of each sensor into a frequency domain signal, obtaining the frequency peak of all frequency domain signals within a specified frequency range, calculating the frequency offset based on the frequency peak and a preset offset coefficient, and constructing an energy integration and phase model within the frequency range obtained by combining the frequency peak and the frequency offset calculation includes: Perform fast Fourier transform on the acoustic emission signals of each sensor to obtain frequency domain signals; Get the frequency peaks of all frequency domain signals within the specified frequency range; Based on the frequency peak value, combined with the preset offset coefficient, the frequency offset is calculated; The energy integral and phase equations are constructed over the frequency range calculated based on the frequency peak and frequency offset.

4. The method for multi-point positioning of annular structure acoustic emission based on energy integration according to claim 3 is characterized in that: Before the fast Fourier transform is performed on the acoustic emission signals of each sensor, the method further includes: Preprocess and segment the collected acoustic emission signals; The preprocessing includes denoising by using a wavelet transform method; the segmentation includes segmenting the preprocessed acoustic emission signal into a plurality of impact events by using a threshold method, and using the preprocessed acoustic emission signal as an acoustic emission signal for fast Fourier transform.

5. The method for multi-point positioning of annular structure acoustic emission based on energy integration according to claim 4 is characterized in that: The method of using a multi-point positioning algorithm to solve the position of the impact point based on the spatial layout position and sound wave velocity of each sensor, combined with energy integration and phase model, includes: Based on each impact event within the time window, the impact point position is preset; According to the spatial layout position and acoustic wave velocity of each sensor, and combined with the energy integration and phase model, the acoustic wave energy and phase model of each sensor is constructed; A multi-point positioning algorithm is used to solve the position of the impact point, including obtaining the predicted data and observed data of the sound wave energy and phase model corresponding to each sensor based on the preset impact point position, defining the objective function to measure the difference between the model predicted data and the observed data, and iteratively solving the impact point position and model parameters.

6. The method for multi-point positioning of annular structure acoustic emission based on energy integration according to claim 5 is characterized in that: Determining the projection point corresponding to the surface of the annular structure according to the position of the impact point, and constructing a confidence ellipsoid based on the projection point includes: Based on the position of the impact point, determine its corresponding projection point on the surface of the annular structure; The covariance matrix is ​​obtained according to the multi-point positioning algorithm, and the confidence ellipsoid is constructed based on the projection points.

7. The method for multi-point positioning of annular structure acoustic emission based on energy integration according to claim 1 is characterized in that: The step of calculating the intersection line of the confidence ellipsoid and the annular structure to define the impact area includes: When the confidence ellipsoid intersects the surface of the annular structure, the intersection line and its corresponding surface portion of the annular structure are defined as the impact area; When the planes of the axial edges of the confidence ellipsoid and the annular structure intersect, the area where the intersection line is located is defined as the impact area; When the confidence ellipsoid does not intersect with the plane where the surface of the annular structure and the axial edge are located, but intersects with the extended plane where the surface of the annular structure is located, the intersection line of the confidence ellipsoid and the extended plane is defined as the impact area.

8. A system for the multi-point positioning method of annular structure acoustic emission based on energy integration as claimed in claim 1, characterized in that: include: The first module is used to collect the acoustic emission signals of all sensors located on the surface of the annular structure at a fixed frequency; The second module is used to convert the acoustic emission signal of each sensor into a frequency domain signal, obtain the frequency peak of all frequency domain signals within a specified frequency range, calculate the frequency offset based on the frequency peak and a preset offset coefficient, and construct an energy integration and phase model within the frequency range obtained by combining the frequency peak and the frequency offset calculation; The third module is used to solve the position of the impact point using a multi-point positioning algorithm based on the spatial layout position of each sensor and the speed of the sound wave, combined with the energy integration and phase model; A fourth module is used to determine the projection point corresponding to the surface of the annular structure according to the position of the impact point, and to construct a confidence ellipsoid based on the projection point; The fifth module is used to calculate the intersection line of the confidence ellipsoid and the ring structure to define the impact area.

9. An electronic device, characterized in that: The electronic device comprises a memory and a processor, the memory stores a computer program, and the processor implements the method according to any one of claims 1 to 7 when executing the computer program.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 7 is implemented.

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