Annular structure acoustic emission multi-point positioning method based on energy integration

Abstract

The invention belongs to the technical field of acoustic emission, and particularly relates to an annular structure acoustic emission multi-point positioning method based on energy integration, which comprises the following steps of: acquiring acoustic emission signals of all sensors on the surface of an annular structure at fixed frequency; converting the acoustic emission signal of each sensor into a frequency domain signal, and constructing an energy integral and phase model based on a specified frequency range; based on the spatial layout position and the sound wave speed of each sensor, combining energy integration and a phase model, and adopting a multi-point positioning algorithm to solve the position of an impact point; determining a 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; and calculating an intersection line of the confidence ellipsoid and the annular structure to define an impact area. The positioning accuracy of the sound source position can be remarkably improved, and the relation between the uncertainty of the positioning result and the geometric shape of the annular structure can be reflected more visually and reasonably.

Description

Technical Field

[0001] The invention belongs to the technical field of acoustic emission, and in particular relates to a multi-point positioning method of acoustic emission of 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 technology is based on the detection and analysis of transient elastic waves (i.e., acoustic emission signals) released by the material during the stress process due to the initiation, expansion, and fracture of internal microcracks. 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 has shown great potential in structural health monitoring, the current acoustic emission positioning method still faces a series of technical challenges. Specifically, the positioning of a single impact point cannot fully reflect the structural state and it is difficult to find the weak area of ​​the structure; the sensor may receive signals from different sources at the same time, making it difficult to accurately classify a specific impact source; in a ring structure, sound waves may propagate along the edge in a loop, 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 at the same time, which is difficult to be effectively handled by existing methods; traditional methods do not take into account the frequency characteristics of the signal, which may lead to a low signal-to-noise ratio and low positioning accuracy. Summary of the invention

[0004] The present invention provides a method for multi-point acoustic emission positioning of an annular structure based on energy integration. By analyzing the energy distribution within a specific frequency range through the collected acoustic emission signals of multiple sensors, the positioning accuracy of the sound source position can be significantly improved, and the impact point position can be solved by multi-point positioning, and then a confidence ellipsoid is constructed. By comparing the confidence ellipsoid with the annular structure, the possible impact area for the entire annular structure surface is determined. The 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 expansibility.

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

[0006] Acquisition of acoustic emission signals from all sensors located on the surface of the annular structure at a fixed frequency;

[0007] Convert the acoustic emission signals of each sensor into frequency domain signals, and construct energy integration and phase models based on the specified frequency range;

[0008] 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;

[0009] 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;

[0010] The intersection line of the confidence ellipsoid and the annulus is calculated to define the impact region.

[0011] By analyzing the energy distribution within a specific frequency range using the acoustic emission signals collected by multiple sensors, the positioning accuracy of the sound source can be significantly improved, and multi-point positioning can be performed to solve the impact point position, and then a confidence ellipsoid can be constructed. By comparing the confidence ellipsoid with the annular structure, the possible impact area on the surface of the entire annular structure can be determined. This method is more intuitive and reasonable, and can directly reflect the relationship between the uncertainty of the positioning result and the geometric shape of the annular structure, and simplifies the judgment process, thereby improving the applicability and interpretability of the method, and it has certain extensibility.

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

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

[0014] Set the time window, set the frequency and synchronously collect the acoustic emission signals of all sensors.

[0015] Furthermore, the converting of the acoustic emission signals of each sensor into frequency domain signals and constructing energy integration and phase models based on a specified frequency range includes:

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

[0017] Get the peak frequency of all frequency domain signals within the specified frequency range;

[0018] Based on the peak frequency and in combination with a preset offset coefficient, a frequency offset is calculated;

[0019] The energy integral and phase equations are constructed over the frequency range calculated based on the frequency peak and frequency offset.

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

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

[0022] 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.

[0023] Furthermore, the method of solving the position of the impact point by using a multi-point positioning algorithm based on the spatial layout position and the speed of the sound wave of each sensor in combination with the energy integration and phase model includes:

[0024] Preset the impact point location based on each impact event within the time window;

[0025] 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;

[0026] 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.

[0027] Further, 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:

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

[0029] The covariance matrix is ​​obtained according to the multi-point positioning algorithm, and the confidence ellipsoid is constructed based on the projection points.

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

[0031] 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;

[0032] 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;

[0033] 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.

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

[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 signal of each sensor into a frequency domain signal and construct an energy integration and phase model based on a specified frequency range;

[0037] 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;

[0038] 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;

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

[0040] An electronic device comprises a memory and a processor, wherein the memory stores a computer program, and the processor implements the above method when executing the computer program.

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

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

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

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

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

[0046] Figure 3 A schematic diagram of the structure of a computer device. DETAILED DESCRIPTION

[0047] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0048] It should be noted that various aspects of the embodiments within the scope of the appended claims are described below. 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 merely illustrative. Based on the present disclosure, it should be understood by those skilled in the art that an 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 the device and / or practice the method. In addition, other structures and / or functionalities other than one or more of the aspects described herein can be used to implement this device and / or practice this method.

[0049] In addition, in the following description, specific details are provided to facilitate a thorough understanding of the examples, and a person of ordinary skill in the art can understand the specific meanings of the above terms in this application under specific circumstances.

[0050] Example 1

[0051] Figure 1 The method shown is a multi-point acoustic emission positioning method for annular structures based on energy integration. By analyzing the energy distribution within a specific frequency range through the collected acoustic emission signals of multiple sensors, the positioning accuracy of the sound source position can be significantly improved, and the impact point position can be solved by multi-point positioning, and then a confidence ellipsoid is constructed. By comparing the confidence ellipsoid with the annular structure, the possible impact area for the entire annular structure surface is determined. This method is more intuitive and reasonable, and can directly reflect the relationship between the uncertainty of the positioning result and the geometric shape of the annular structure, and simplifies the judgment process, improving the applicability and interpretability of the method, and it has certain extensibility. It specifically includes the following steps:

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

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

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

[0055] The coordinate position of the second sensor on the surface of the annular structure is

[0056] The coordinate position of the third sensor on the surface of the annular structure is

[0057] Where r represents the radius of the ring structure.

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

[0059] The acoustic emission signals of all sensors located on the surface of the annular structure are collected at a fixed frequency, including:

[0060] S11: Set the time window T, set the frequency and synchronously collect the acoustic emission signals of all sensors.

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

[0062] It should be noted that the time windows may be set to be continuous and connected, or may be set to be continuous and overlapping time windows.

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

[0064] S2: Convert the acoustic emission signals of each sensor into frequency domain signals, and construct energy integration and phase models based on the specified frequency range;

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

[0066] Among them, the expression of 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 frequency of all frequency domain signals within a specified frequency range;

[0071] Among them, the expression of the peak frequency fp of 100~150kHz is:

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

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

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

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

[0076] The frequency offset expression is:

[0077] F_shift = α·fp;

[0078] Wherein, F_shift represents the frequency shift; α represents the shift coefficient, which can be 0.00001 or selected according to the actual situation.

[0079] S24: Constructing energy integration and phase equations within the frequency range calculated based on the frequency peak and the frequency offset.

[0080] Based on the peak frequency value and the frequency shift value, the frequency range is determined to be [fp-F, fp+F_shift].

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

[0082]

[0083] Where E represents the energy integral;

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

[0085]

[0086] Where θ represents the phase.

[0087] S3: Based on the spatial layout of each sensor and the speed of the sound wave, the multi-point positioning algorithm is used to solve the position of the impact point in combination with the energy integration and phase model;

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

[0089] S32: constructing the acoustic wave energy and phase model of each sensor according to the spatial layout position and acoustic wave velocity of each sensor and in combination with the energy integration and phase model;

[0090] Among them, the expressions of the acoustic wave energy and phase model of each sensor are:

[0091]

[0092] In the formula, E i represents the sound 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 i-th sensor

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

[0094] S33: Using a multi-point positioning algorithm 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 P, and iteratively solving the impact point position P

[0095] and model parameters;

[0096] In this embodiment, the multi-point positioning algorithm selects nonlinear least squares method (such as Levenberg-Marquardt algorithm) and transforms the fitting problem into the objective function minimization problem to measure the difference between the model prediction 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 ) is:

[0097]

[0098] Where F represents the objective function; E i_measured represents the actual measured value of the acoustic wave energy of the ith sensor, i.e., the energy integral value; E i_calculated represents the theoretical measurement value of the acoustic wave energy of the ith sensor, i.e., 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 by the phase equation; θ i_calculated represents the theoretical measurement value of the phase of the i-th sensor, that is, the phase value obtained by the acoustic wave energy and phase model; represents the standard deviation of the phase of the ith sensor.

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

[0100]

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

[0102]

[0103] Where H(k) represents the frequency response function;

[0104] The expression of the phase value obtained by the phase equation based on the actual measurement value of the i-th sensor phase is:

[0105]

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

[0107] The expression of the phase value obtained by the bit 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 energy and phase prediction data of each sensor according to the acoustic energy and phase model, and compare it with the actual observation data to calculate the objective function value, and then update the objective function parameters by minimizing the objective function, iterate until the convergence condition is met, and then get the impact point position

[0111] P, as well as the constant K, the attenuation coefficient σ and the initial phase θ 0 Parameter value.

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

[0113] S41: Based on the impact point position P, determine its corresponding projection point P on the surface of the annular structure ′ ;

[0114] S42: Obtain the covariance matrix based on the multi-point positioning algorithm, and ′ Construct a confidence ellipsoid.

[0115] In this embodiment, when the multi-point positioning algorithm is used, that is, the nonlinear least square method is selected for iterative solution, the Jacobian matrix approximation is constructed by the matrix of the partial derivative of the objective function for each parameter to iteratively update the objective function parameter.

[0116] The covariance matrix is ​​obtained to describe the degree of deviation between the parameters of each objective function. Specifically, it includes:

[0117] S421: Based on the objective function F(P(x,y,z),K,σ,θ 0 ), calculate the partial derivative of each parameter to construct the Jacobian matrix;

[0118] The expression of Jacobian matrix is:

[0119]

[0120] Where, 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 Jacobian matrix can be approximated by numerical methods (such as the central difference method).

[0124] S422: constructing a weight matrix W based on the values ​​obtained from the acoustic wave energy and phase model of each sensor and the attenuation coefficient σ;

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

[0126]

[0127] Where W represents the weight matrix; diag() represents extracting the diagonal matrix.

[0128] S423: Construct a covariance matrix based on the Jacobian matrix and the weight matrix;

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

[0130] ∑=(J T ·W·J) -1

[0131] Where, ∑ 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] (xx 0 ) T ·∑ -1 ·(xx 0 ) = x 2 (3,0.95);

[0134] In the formula, x 0 represents the estimated impact point position; ∑ 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 ring structure, it is necessary to compare and determine the positional intersection relationship between the confidence ellipsoid and the ring structure, and then define the impact area. That is:

[0137] S51: 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;

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

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

[0140] In this embodiment, a numerical calculation method (such as 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 an arc or other shape.

[0141] S52: 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;

[0142] The plane equation defining the plane where the axial edge of the annular structure lies is:

[0143]

[0144] Wherein, H represents the height of the ring structure.

[0145] S53: 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.

[0146] It should be noted that the expansion plane is adjacent to the surface of the annular structure or the plane where the axial edge is located in space. The comparison and judgment of the expansion plane is 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] Example 2

[0148] Based on the same technical concept, such as Figure 2 As shown, an embodiment of the present application provides an annular structure acoustic emission multi-point positioning system based on energy integration, 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 signal of each sensor into a frequency domain signal 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 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;

[0152] Specifically, the 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;

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

[0154] Example 3

[0155] Based on the same technical concept, the embodiment of the present application also provides a computer device, including a memory 1 and a processor 2, such as Figure 3 As shown, the memory 1 stores a computer program, and the processor 2 implements any of the above-mentioned methods when executing the computer program.

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

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

[0158] The disclosed embodiment of the present invention further provides a computer-readable storage medium, on which a computer program is stored, and the computer program is executed by a processor to perform the steps of the method described in the above method embodiment. The storage medium can be a volatile or non-volatile computer-readable storage medium.

[0159] The computer program product of the application page content refresh method provided in the disclosed embodiment 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 embodiment. For details, please refer to the above method embodiment, which will not be repeated here.

[0160] The disclosed embodiment of the present invention also provides a computer program, which implements any one of the methods of the aforementioned embodiments when executed by a processor. The computer program product can be implemented in hardware, software or a combination thereof. In an optional embodiment, the computer program product is specifically embodied as a computer storage medium, and in another optional embodiment, the computer program product is specifically embodied as a software product, such as a software development kit (SDK) and the like.

[0161] It can be understood that the same or similar parts of the above embodiments can be referenced to each other, and the contents not described in detail in some embodiments can refer to the same or similar contents 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 "plurality" refers to at least two.

[0163] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code that includes one or more executable instructions for implementing the steps of a specific logical function or process, and the scope of the preferred embodiments of the present invention includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by those skilled in the art to which the embodiments of the present invention belong.

[0164] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of 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, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0165] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0166] In addition, each functional unit in each embodiment of the present invention may be integrated into a processing module, or each unit may exist physically separately, 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. If 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 storage medium mentioned above can be a read-only memory, a magnetic disk or an optical disk, etc.

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

[0169] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary 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; Convert the acoustic emission signals of each sensor into frequency domain signals, and construct energy integration and phase models based on the specified frequency range; 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 step of 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 includes: Perform fast Fourier transform on the acoustic emission signals of each sensor to obtain frequency domain signals; Get the peak frequency of all frequency domain signals within the specified frequency range; Based on the peak frequency and in combination with a preset offset coefficient, a 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 performing fast Fourier transform on the acoustic emission signal 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 and construct an energy integration and phase model based on a specified frequency range; 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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