阅读说明：本技术 一种基于正方体阵列的声发射源定位方法及系统 (Cube array-based acoustic emission source positioning method and system ) 是由 刘志兵 陈洪涛 王西彬 刘书尧 焦黎 解丽静 梁志强 颜培 周天丰 于 2020-12-29 设计创作，主要内容包括：本发明公开了一种基于正方体阵列的声发射源定位方法及系统,涉及声发射定位检测领域。声发射检测技术是一种重要的无损检测方法,通过及时发现损伤及潜在威胁从而保障结构的安全性。本发明包括正方体阵列布置声发射传感器,利用互相关函数确定声发射传感器时间差,根据试验标定确定是否调整声发射传感器的距离,接着采集声发射信号,利用互相关函数计算确定时间差,最后根据时间差和正方体边长确定声发射源位置。本发明不涉及到声发射速度,不受材料各向同性和各向异性的影响。计算时不需要迭代过程,提高了计算的速度和准确性,更加适用于三维结构的声发射源定位。(The invention discloses an acoustic emission source positioning method and system based on a cube array, and relates to the field of acoustic emission positioning detection. The acoustic emission detection technology is an important nondestructive detection method, and the safety of the structure is guaranteed by timely discovering damage and potential threats. The method comprises the steps of arranging acoustic emission sensors in a cube array, determining time difference of the acoustic emission sensors by using a cross-correlation function, determining whether to adjust the distance of the acoustic emission sensors according to test calibration, then acquiring acoustic emission signals, calculating and determining the time difference by using the cross-correlation function, and finally determining the position of an acoustic emission source according to the time difference and the side length of the cube. The invention does not relate to the sound emission speed and is not influenced by the isotropy and the anisotropy of the material. The iterative process is not needed during calculation, the calculation speed and accuracy are improved, and the method is more suitable for positioning the acoustic emission source with a three-dimensional structure.)

1. A method for positioning an acoustic emission source based on a cube array is characterized by comprising the following steps:

establishing an acoustic emission source positioning sensor in a cubic array arrangement of a three-dimensional structure;

the received acoustic signal of the acoustic emission is converted into an electrical signal of the acoustic emission by the acoustic emission sensor;

the acoustic emission electric signal enters a signal acquisition and processing system;

performing cross-correlation function calculation on the electric signals passing through the signal acquisition and processing system, wherein the time difference between adjacent wave crests of the cross-correlation function is the required time difference tau obtained by the acoustic emission signals;

and determining the position of the sound emission source according to the time difference tau.

2. A method for positioning an acoustic emission source based on a square array according to claim 1, wherein the cross-correlation function is calculated as follows: the cross-correlation function between any one wave A (t) and another wave B (t + τ) with a delay time τ is as follows:

any one of the functions A (t) and the function B (t) with time delay tau ', and the cross-correlation function R of the two functions A (t) and B (t + tau') in a finite time interval_AB(τ) contains a maximum value when τ ═ τ'.

3. A method as claimed in claim 1 wherein the side length of the cube array is d, and the time difference τ is used to derive the position P (x, y, z) of the acoustic emission source, which is the distanceIf l > d and r > d, continuing to detect; conversely, the distance of the acoustic emission sensor is adjusted until l > d and r > d are satisfied.

4. A method as claimed in claim 3 wherein the method comprises the following steps:

first acoustic emission sensor S₁Second acoustic emission sensor S₂A third acoustic emission sensor S₃A fourth acoustic emission sensor S₄As a group, the second acoustic emission sensor S₂The third acoustic emission sensor S₃The fourth acoustic emission sensor S₄With said first acoustic emission sensor S₁Respectively is Deltat₁₂、Δt₁₃、Δt₁₄；S₁P is l, P is in the first acoustic emission sensor S₁The projection in the plane of the coordinate system xoy as the origin of coordinates is P_xy1P in said first acoustic emission sensor S₁Projection in the yoz plane of the coordinate system as origin of coordinates is P_yz(ii) a x-axis and S₁P has an included angle of alpha₁Y-axis and S₁P has an included angle of alpha₂Z-axis and S₁P has an included angle of alpha₃Y-axis and S₁P_xy1Has an included angle of beta₁Z-axis and S₁P_yzHas an included angle of beta₂(ii) a When l > d and r > d, we find:

due to P_xy1Point P is on the first acoustic emission sensor S₁The projection in the plane of the coordinate system xoy, which is the origin of coordinates, has:

the two formulas are compared to obtain:

due to P_yzPoint P is on the first acoustic emission sensor S₁The projection in the yoz plane of the coordinate system, which is the origin of coordinates, has:

the two formulas are compared to obtain:

point P is on the first acoustic emission sensor S₁The coordinate of the coordinate system as the origin of coordinates is set to (x)_p1，y_p1，z_p1) Then, there is,

obtaining:

fifth acoustic emission sensor S₅Sixth acoustic emission sensor S₆Seventh acoustic emission sensor S₇The eighth acoustic emission sensor S₈As a group, the sixth acoustic emission sensor S₆Said seventh acoustic emission sensor S₇The eighth acoustic emission sensor S₈And said fifth acoustic emission sensor S₅Respectively is Deltat₅₆、Δt₅₇、Δt₅₈；S₅P is r, P is in said fifth acoustic emission sensor S₅The projection in the plane of the coordinate system xoy as the origin of coordinates is P_xy5P at said fifth acoustic emission sensor S₅Projection in the yoz plane of the coordinate system as origin of coordinates is P_yz(ii) a x-axis and S₅P has an included angle theta₁Y-axis and S₅P has an included angle theta₂Z-axis and S₅P has an included angle theta₃(ii) a y-axis and S₅P_xy5Is gamma₁Z-axis and S₅P_yzIs gamma₂(ii) a When l > d and r > d, we find:

due to P_xy5Point P is on the fifth acoustic emission sensor S₅The projection in the plane of the coordinate system xoy, which is the origin of coordinates, has:

the two formulas are compared to obtain:

due to P_yzPoint P is on the fifth acoustic emission sensor S₅The projection in the yoz plane of the coordinate system, which is the origin of coordinates, has:

rcosθ₂＝rcosθ₁sinγ₂；

rcosθ₃＝rcosθ₁cosγ₂；

the two formulas are compared to obtain:

point P is on the fifth acoustic emission sensor S₅The coordinate of the coordinate system as the origin of coordinates is set to (x)_p5，y_p5，z_p5) Then, there is,

obtaining:

wherein x is_p5＝x_p1-d、y_p5＝y_p1-d、z_p5＝z_p1-d, taken together:

the location of the acoustic emission source is determined.

5. The utility model provides an acoustic emission source positioning system based on square array which characterized in that, includes acoustic emission sensor, signal amplifier, signal acquisition and processing system, demonstration and recording system, acoustic emission sensor with signal amplifier passes through the signal line and connects, signal amplifier passes through the signal line and connects signal acquisition and processing system, signal acquisition and processing system and demonstration and recording system pass through the signal line and are connected.

6. A cube array based acoustic emission source localization system according to claim 5, wherein the signal acquisition and processing system performs a cross-correlation function calculation on the acquired acoustic emission signals to obtain time differences between the sensors, and finally determines the position of the acoustic emission source by using the time differences and the cube side length through a recording and display system.

Technical Field

The invention relates to the field of acoustic emission dynamic detection, in particular to a method and a system for positioning an acoustic emission source by using an acoustic emission time difference method.

Background

Acoustic emission is the phenomenon of transient elastic waves generated by the rapid release of local source energy inside a material. Monitoring the process with an acoustic emission sensor is very efficient and the detection of faults due to the sensor is very sensitive to the process and more reliable. Acoustic emission technology is considered one of the most accurate monitoring methods in machining, has relatively superior signal-to-noise ratio and sensitivity, and is more advantageous than conventional sensors.

Currently, acoustic emission localization technology plays an increasingly important role in engineering, and due to the diversity of loads and the complexity of the external environment, micro-damage such as cracks and cavities often occurs inside engineering materials during application. Under external loading, these micro-damage can propagate further, resulting in failure of the material or structure. Monitoring the location of the micro-defects that produce the acoustic emission source is of great significance in the engineering field. Surface defects and material damage points in engineering often need to be monitored and positioned in real time by using an acoustic emission technology. The signal received by the acoustic emission sensor is sent by the detected object, and the internal defect of the detected object actively participates in the detection process, which is the essential difference between the acoustic emission detection technology and other nondestructive detection technologies, and has the irreplaceable superiority of other detection methods.

The micro-defects of the material are located through acoustic emission signals, and a time difference location method, an area location method, a correlation location method, a pattern recognition location method and the like are generally used, wherein the time difference location method is the most widely applied method. The principle of the time difference positioning method is that according to the time difference of the acoustic emission signals emitted by the same acoustic emission source reaching each acoustic emission sensor and the space position of each acoustic emission sensor, the geometric relation series linear equation set of the acoustic emission source and the acoustic emission sensor is used for solving.

Disclosure of Invention

In view of the above, the present invention provides a method and a system for positioning an acoustic emission source based on a cube array.

In order to achieve the purpose, the invention adopts the following technical scheme:

a method for positioning an acoustic emission source based on a cube array comprises the following steps:

establishing an acoustic emission source positioning sensor in a cubic array arrangement of a three-dimensional structure;

the received acoustic signal of the acoustic emission is converted into an electrical signal of the acoustic emission by the acoustic emission sensor;

the acoustic emission electric signal enters a signal acquisition and processing system;

performing cross-correlation function calculation on the electric signals passing through the signal acquisition and processing system, wherein the time difference between adjacent wave crests of the cross-correlation function is the required time difference tau obtained by the acoustic emission signals;

and determining the position of the sound emission source according to the time difference tau.

Preferably, the cross-correlation function calculation process is specifically as follows: the cross-correlation function between any one wave A (t) and another wave B (t + τ) with a delay time τ is as follows:

any one of the functions A (t) and the function B (t) with time delay tau ', and the cross-correlation function R of the two functions A (t) and B (t + tau') in a finite time interval_AB(τ) contains a maximum value at τ ═ τ', and this cross-correlation method is used for localization of continuous acoustic sources.

Preferably, the side length of the square array is d, and the acoustic emission is obtained by using the time difference tauPosition P (x, y, z) of the source, thenIf l > d and r > d, continuing to detect; conversely, the distance of the acoustic emission sensor is adjusted until l > d and r > d are satisfied. Wherein much larger means two orders of magnitude-100 times more.

Preferably, the acoustic emission source positioning method is as follows:

first acoustic emission sensor S₁Second acoustic emission sensor S₂A third acoustic emission sensor S₃A fourth acoustic emission sensor S₄As a group, the second acoustic emission sensor S₂The third acoustic emission sensor S₃The fourth acoustic emission sensor S₄With said first acoustic emission sensor S₁Respectively is Deltat₁₂、Δt₁₃、Δt₁₄；S₁P is l, P is in the first acoustic emission sensor S₁The projection in the plane of the coordinate system xoy as the origin of coordinates is P_xy1P in said first acoustic emission sensor S₁Projection in the yoz plane of the coordinate system as origin of coordinates is P_yz(ii) a x-axis and S₁P has an included angle of alpha₁Y-axis and S₁P has an included angle of alpha₂Z-axis and S₁P has an included angle of alpha₃Y-axis and S₁P_xy1Has an included angle of beta₁Z-axis and S₁P_yzHas an included angle of beta₂；

When l > d and r > d, we find:

due to P_xy1Point P is on the first acoustic emission sensor S₁The projection in the plane of the coordinate system xoy, which is the origin of coordinates, has:

the two formulas are compared to obtain:

due to P_yzPoint P is on the first acoustic emission sensor S₁The projection in the yoz plane of the coordinate system, which is the origin of coordinates, has:

the two formulas are compared to obtain:

point P is on the first acoustic emission sensor S₁The coordinate of the coordinate system as the origin of coordinates is set to (x)_p1，y_p1，z_p1) Then, there is,

obtaining:

fifth acoustic emission sensor S₅Sixth acoustic emission sensor S₆Seventh acoustic emission sensor S₇The eighth acoustic emission sensor S₈As a group, the sixth acoustic emission sensor S₆Said seventh acoustic emission sensor S₇The eighth acoustic emission sensor S₈And said fifth acoustic emission sensor S₅Respectively is Deltat₅₆、Δt₅₇、Δt₅₈；S₅P is r, P is in said fifth acoustic emission sensor S₅The projection in the plane of the coordinate system xoy as the origin of coordinates is P_xy5P at said fifth acoustic emission sensor S₅Projection in the yoz plane of the coordinate system as origin of coordinates is P_yz(ii) a x-axis and S₅P has an included angle theta₁Y-axis and S₅P has an included angle theta₂Z-axis and S₅P has an included angle theta₃(ii) a y-axis and S₅P_xy5Is gamma₁Z-axis and S₅P_yzIs gamma₂；

When l > d and r > d, we find:

due to P_xy5Point P is on the fifth acoustic emission sensor S₅The projection in the plane of the coordinate system xoy, which is the origin of coordinates, has:

the two formulas are compared to obtain:

due to P_yzPoint P is on the fifth acoustic emission sensor S₅The projection in the yoz plane of the coordinate system, which is the origin of coordinates, has:

rcosθ₂＝rcosθ₁sinγ₂；

rcosθ₃＝rcosθ₁cosγ₂；

the two formulas are compared to obtain:

point P is on the fifth acoustic emission sensor S₅The coordinate of the coordinate system as the origin of coordinates is set to (x)_p5，y_p5，z_p5) Then, there is,

obtaining:

wherein x is_p5＝x_p1-d、y_p5＝y_p1-d、z_p5＝z_p1-d, taken together:

the location of the acoustic emission source is determined.

The utility model provides an acoustic emission source positioning system based on square array, positioning system includes acoustic emission sensor, signal amplifier, signal acquisition and processing system, demonstration and recording system, acoustic emission sensor with signal amplifier passes through the signal line and connects, signal amplifier passes through the signal line and connects signal acquisition and processing system, signal acquisition and processing system and demonstration and recording system pass through the signal line and are connected.

Preferably, the signal acquisition and processing system performs cross-correlation function calculation on the acquired acoustic emission signals to obtain time differences among the sensors, and finally determines the position of the acoustic emission source by using the time differences and the cube side length through a recording and display system.

According to the technical scheme, compared with the prior art, the invention discloses and provides the acoustic emission source positioning method and system based on the cube array, and the method and system have the following beneficial effects:

(1) the acoustic emission is a dynamic detection method, and the energy detected by the acoustic emission comes from the object to be detected, so that the detection accuracy is improved.

(2) The method is insensitive to the geometric shape of the measured object and is suitable for detecting the components with complex shapes, and other methods are limited. And is also suitable for environment detection which is difficult or inaccessible by other methods.

(3) The positioning method is irrelevant to the propagation speed of the acoustic emission signal, and the influence of the difference of the propagation speed of the acoustic emission signal caused by material anisotropy is avoided.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

FIG. 1 is a schematic flow diagram of the process of the present invention;

FIG. 2 is a schematic diagram of the cross-correlation function time difference calculation of the present invention;

FIG. 3 is a diagram of a square array layout of the present invention;

FIG. 4 is a schematic diagram of the position P of the acoustic emission source of the present invention;

FIG. 5 is a schematic diagram illustrating the definition of an acoustic emission source in accordance with the present invention;

FIG. 6 is a schematic system flow diagram of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1:

the embodiment discloses an acoustic emission source positioning method and system based on a cube array. The invention does not relate to the sound emission speed and is not influenced by the isotropy and the anisotropy of the material. The iterative process is not needed during calculation, the calculation speed and accuracy are improved, and the method is more suitable for positioning the acoustic emission source with a three-dimensional structure. The acoustic emission detection technology is an important nondestructive detection method, and the safety of the structure is guaranteed by timely discovering damage and potential threats. The invention provides a new method for positioning an acoustic emission source in acoustic emission detection, and as shown in figure 1, the method for positioning the acoustic emission source based on a cube array comprises the following steps: establishing an acoustic emission source positioning sensor in a cubic array arrangement of a three-dimensional structure; the received acoustic signal of the acoustic emission is converted into an electrical signal of the acoustic emission by the acoustic emission sensor; the acoustic emission electric signal enters a signal acquisition and processing system; performing cross-correlation function calculation on the electric signals passing through the signal acquisition and processing system, wherein the time difference between adjacent wave crests of the cross-correlation function is the required time difference tau obtained by the acoustic emission signals; the position of the acoustic emission source is determined from the time difference τ.

Preferably, as shown in fig. 2, the specific process of time difference of the cross-correlation function is as follows:

the cross-correlation function represents the degree of correlation between two time series, i.e. describing the signals x (t), y (t) at any two different times t₁，t₂The degree of correlation between the values of (a). The signals are most closely correlated at a time interval τ apart, which reflects the lag time of the main transmission channel between the two signals x (t), y (t). Performing cross-correlation function analysis on the two collected acoustic emission signals to obtain corresponding cross-correlation function images, wherein a time interval tau corresponding to a maximum peak value on the cross-correlation function images is a time difference tau between the acoustic emission signals, and a cross-correlation function between any wave A (t) and another wave B (t + tau) with a delay time tau is as follows:

any one of the functions A (t) and the function B (t) with time delay tau ', and the cross-correlation function R of the two functions A (t) and B (t + tau') in a finite time interval_AB(τ) must contain a maximum value when τ ═ τ', and this cross-correlation method is used for the localization of the continuous mode acoustic emission sources. If the acoustic emission sensor A receives a continuous acoustic emission signal A (t), the acoustic emission sensor B receives a continuous acoustic emission signal B (t + τ ') with a time delay τ' relative to the wave A (t), then the time difference between the propagation of the acoustic emission signal from the source to the two probes may be determined from its cross-correlation function R_ABThe maximum peak position of (τ), i.e. Δ t_AB＝τ′。

As shown in fig. 4, the eight acoustic emission sensors are arranged in an array of a cube, and are placed at eight vertices of the cube, respectively, as shown in the following figure. The side length of the cube is d, in S₁A coordinate system is established for the origin of coordinates.

Firstly, collecting acoustic emission signals to perform cross-correlation function calculation to obtain an acoustic emission sensorThe time difference between them, from which the position P (x, y, z) of the source of sound emission can be derived, is then If l > d and r > d, detection continues. Conversely, the distance of the acoustic emission sensor is adjusted until l > d and r > d are satisfied. Wherein, far more than two orders of magnitude-more than 100 times.

Preferably, as shown in fig. 5, the specific procedure for the acoustic emission source determination is as follows:

first acoustic emission sensor S₁Second acoustic emission sensor S₂A third acoustic emission sensor S₃A fourth acoustic emission sensor S₄As a group, a second acoustic emission sensor S₂A third acoustic emission sensor S₃A fourth acoustic emission sensor S₄With a first acoustic emission sensor S₁Respectively, are Δ t₁₂、Δt₁₃、Δt₁₄；S₁P is l, P is in the first acoustic emission sensor S₁The projection in the plane of the coordinate system xoy as the origin of coordinates is P_xy1P is in the first acoustic emission sensor S₁Projection in the yoz plane of the coordinate system as origin of coordinates is P_yz(ii) a x-axis and S₁P has an included angle of alpha₁Y-axis and S₁P has an included angle of alpha₂Z-axis and S₁P has an included angle of alpha₃Y-axis and S₁P_xy1Has an included angle of beta₁Z-axis and S₁P_yzHas an included angle of beta₂；

When l > d and r > d, we find:

due to P_xy1Is point P on the first acoustic emission sensor S₁The projection in the plane of the coordinate system xoy, which is the origin of coordinates, has:

the two formulas are compared to obtain:

due to P_yzIs point P on the first acoustic emission sensor S₁The projection in the yoz plane of the coordinate system, which is the origin of coordinates, has:

the two formulas are compared to obtain:

point P is on the first acoustic emission sensor S₁The coordinate of the coordinate system as the origin of coordinates is set to (x)_p1，y_p1，z_p1) Then, there is,

obtaining:

fifth acoustic emission sensor S₅Sixth acoustic emission sensor S₆Seventh acoustic emission sensor S₇The eighth acoustic emission sensor S₈As a set, sixth acoustic emission sensors S₆Seventh acoustic emission sensor S₇The eighth acoustic emission sensor S₈With a fifth acoustic emission sensor S₅Respectively is Deltat₅₆、Δt₅₇、Δt₅₈；S₅P is r, P is at the fifth acoustic emission sensor S₅The projection in the plane of the coordinate system xoy as the origin of coordinates is P_xy5P in a fifth acoustic emission sensor S₅Projection in the yoz plane of the coordinate system as origin of coordinates is P_yz(ii) a x-axis and S₅P has an included angle theta₁Y-axis and S₅P has an included angle theta₂Z-axis and S₅P has an included angle theta₃(ii) a y-axis and S₅P_xy5Is gamma₁Z-axis and S₅P_yzIs gamma₂；

When l > d and r > d, we find:

due to P_xy5Point P is at a fifth acoustic emission sensor S₅The projection in the plane of the coordinate system xoy, which is the origin of coordinates, has:

the two formulas are compared to obtain:

due to P_yzPoint P is at a fifth acoustic emission sensor S₅The projection in the yoz plane of the coordinate system, which is the origin of coordinates, has:

rcosθ₂＝rcosθ₁sinγ₂；

rcosθ₃＝rcosθ₁cosγ₂；

the two formulas are compared to obtain:

point P is at a fifth acoustic emission sensor S₅The coordinate of the coordinate system as the origin of coordinates is set to (x)_p5，y_p5，z_p5) Then, there is,

obtaining:

wherein x is_p5＝x_p1-d、y_p5＝y_p1-d、z_p5＝z_p1-d, taken together:

the position of the acoustic emission source is determined and the position of the acoustic emission source in visible three-dimensional space can be determined by eight acoustic emission sensors of the cube array.

Example 2:

example 2 differs from example 1 only in the following, the rest being the same, see example 1 for the same parts.

An acoustic emission source positioning system based on a cube array is shown in fig. 6, and comprises an acoustic emission sensor, a signal amplifier, a signal acquisition and processing system, and a display and recording system. The acoustic emission sensor is connected with the signal amplifier through a signal line, the signal amplifier is connected with the signal acquisition and processing system through a signal line, and the signal acquisition and processing system and the display and recording system are connected through a signal line. Wherein the acoustic emission sensor is operative to convert received acoustic signals of acoustic emissions into acoustic signals of acoustic emissions. The model of the acoustic emission sensor is SR150M of Songhua technology company, the frequency is 6 kHz-400 kHz, the number is 8, and the acoustic emission sensor is fixed on eight vertexes of the cube array through a medium-temperature silicone grease coupling agent. The acoustic emission sensor is connected with the amplifier through a signal wire, and the amplifier mainly amplifies weak input signals, so that the signal-to-noise ratio of the signals is improved, and the attenuation of the signals is prevented. The signal acquisition and processing system adopts a 16-channel acquisition card of the Voronoi Hua science and technology company, the sampling frequency is 10MHz, and the sampling precision is 16 bits. The method comprises the following specific steps:

a three-dimensional structure acoustic emission source positioning sensor array was created as shown in fig. 3. Constructing a cube with the side length of d, and respectively arranging eight acoustic emission sensors at eight vertexes of the cube by S₁And establishing a space rectangular coordinate system for the coordinate origin. S₁、S₂、S₃、S₄、S₅、S₆、S₇、S₈As shown in fig. 3.

And the acoustic emission signal is processed by an acoustic emission sensor and enters a signal acquisition and processing system.

Mutual interaction of collected acoustic emission signalsAnd (4) calculating a correlation function, and calculating an acoustic emission signal to obtain the required time difference. Although the exact time at which the sound waves are generated and the exact moment at which the sound waves arrive at the acoustic emission sensors are unknown, the time difference between any two acoustic emission sensors is known. Determining a second acoustic emission sensor S₂A third acoustic emission sensor S₃A fourth acoustic emission sensor S₄With a first acoustic emission sensor S₁Respectively is Deltat₁₂、Δt₁₃、Δt₁₄Sixth Acoustic emission sensor S₆Seventh acoustic emission sensor S₇The eighth acoustic emission sensor S₈With a fifth acoustic emission sensor S₅Respectively is Deltat₅₆、Δt₅₇、Δt₅₈。

And finally, determining the position of the acoustic emission source by using the time difference and the cube side length through a recording and displaying system.

The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. The device disclosed by the embodiment corresponds to the method disclosed by the embodiment, so that the description is simple, and the relevant points can be referred to the method part for description.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.