A wave packet separation method, device and equipment based on sparse comb lattice

Abstract

The present invention provides a wave packet separation method, device and equipment based on sparse comb lattice, which relates to the field of wave packet separation technology, including obtaining the time domain signal of the waveguide based on multiple signal receiving points; calculating the dispersion information through the time domain signal; calculating the optimal receiving point spacing of the sensor; setting the sensor point through the optimal receiving point spacing to obtain the sensor sparse comb receiving lattice; constructing a frequency response matrix based on the dispersion information, calculating the frequency response vector based on the sensor sparse comb receiving lattice, and calculating the total modal frequency amplitude coefficient in the waveguide propagation based on the frequency response matrix and the frequency response vector; based on the total modal frequency amplitude coefficient, obtaining the time domain response of each mode at different sensor points through inverse Fourier transform to complete wave packet separation. The present invention solves the problem that the traditional method cannot meet the practicality and accuracy requirements of non-destructive monitoring of on-site waveguide structures.

Description

Technical Field

[0001] The present invention relates to the technical field of wave packet separation, and in particular to a wave packet separation method, device and equipment based on a sparse comb lattice. Background Art

[0002] There are many guided wave modes in waveguide structures with irregular complex cross-sections. At high frequencies, the guided waves of multiple modes will be mixed together, which is not conducive to mode identification and application in damage monitoring. In order to meet the needs of non-destructive testing and structural health monitoring for single mode analysis, an applicable wave packet separation method must be proposed.

[0003] However, the traditional wave packet separation method has large errors in the calculation of the propagation characteristics of the waveguide structure, and requires the setting of a large number of signal receiving points to ensure the effective implementation of the algorithm. It consumes a lot of resources in the real-time monitoring process of the structure and has poor feasibility. In addition, the signal separation method based on cloud image processing is prone to loss of effective information.

[0004] Therefore, the traditional wave packet separation method cannot meet the practicality and accuracy requirements of on-site non-destructive monitoring of waveguide structures. Summary of the invention

[0005] The purpose of the present invention is to provide a wave packet separation method, device and equipment based on a sparse comb lattice to improve the above problems. In order to achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0006] In a first aspect, the present application provides a wave packet separation method based on a sparse comb lattice, comprising:

[0007] Acquire a time domain signal of the waveguide based on a plurality of signal receiving points, wherein the signal receiving points are evenly spaced on the waveguide structure to be monitored, and the relative position of each of the signal receiving points on the cross section of the waveguide structure is the same as the relative position of the signal excitation point on the cross section of the waveguide structure;

[0008] Calculating dispersion information through the time domain signal;

[0009] Obtaining the total number of modes of the waveguide, the wave value values ​​of each mode at different angular frequencies and the length of the effective angular frequency vector, and calculating the optimal receiving point spacing of the sensor based on the total number of modes, the wave value values ​​and the length of the effective angular frequency vector;

[0010] The sensor points are set by the optimal receiving point spacing to obtain a sparse comb-shaped receiving point array of the sensor, and the sensor points are located at the signal receiving points;

[0011] Based on the frequency dispersion information, a frequency response matrix is ​​constructed, based on the sparse comb receiving point matrix of the sensor, a frequency response vector is calculated, and based on the frequency response matrix and the frequency response vector, a total modal frequency amplitude coefficient in the guided wave propagation is calculated;

[0012] Based on the total modal frequency amplitude coefficient, the time domain response of each mode at different sensor points is obtained by inverse Fourier transform to complete wave packet separation.

[0013] In a second aspect, the present application further provides a wave packet separation device based on a sparse comb lattice, comprising:

[0014] A signal acquisition module, used for acquiring a time domain signal of the waveguide based on a plurality of signal receiving points, wherein the signal receiving points are evenly spaced on the waveguide structure to be monitored, and the relative position of each of the signal receiving points on the cross section of the waveguide structure is the same as the relative position of the signal excitation point on the cross section of the waveguide structure;

[0015] A first calculation module, used for calculating dispersion information through the time domain signal;

[0016] A second calculation module is used to obtain the total number of modes of the waveguide, the wave value of each mode at different angular frequencies and the length of the effective angular frequency vector, and calculate the optimal receiving point spacing of the sensor based on the total number of modes, the wave value and the length of the effective angular frequency vector;

[0017] A point setting module, used for setting sensor points according to the optimal receiving point spacing to obtain a sparse comb-shaped receiving dot matrix of the sensor, wherein the sensor points are located at the signal receiving points;

[0018] A third calculation module is used to construct a frequency response matrix based on the frequency dispersion information, calculate a frequency response vector based on the sparse comb receiving point matrix of the sensor, and calculate a total modal frequency amplitude coefficient in guided wave propagation based on the frequency response matrix and the frequency response vector;

[0019] The fourth calculation module is used to obtain the time domain response of each mode at different sensor points through inverse Fourier transform based on the total modal frequency amplitude coefficient to complete wave packet separation.

[0020] In a third aspect, the present application further provides a wave packet separation device based on a sparse comb lattice, comprising:

[0021] Memory for storing computer programs;

[0022] A processor is used to implement the steps of the wave packet separation method based on sparse comb lattice when executing the computer program.

[0023] The beneficial effects of the present invention are as follows: the present invention arranges a series of sensors on the actual waveguide structure to be monitored and obtains the precise propagation characteristics of the waveguide structure in combination with two-dimensional Fourier transform, thereby avoiding the error of the semi-analytical finite element method and making up for the defect of large propagation characteristic calculation error in the traditional modal separation algorithm. In addition, through the calculation of the optimal receiving point spacing of the sensor and the calculation of the frequency response matrix equation, the guided wave packet separation based on sparse points is realized, which solves the problems of difficulty in arranging a large number of points and large resource requirements, and lays a foundation for the application of wave packet separation in the health monitoring of actual waveguide structures.

[0024] Other features and advantages of the present invention will be set forth in the following description, and in part will become apparent from the description, or may be understood by practicing embodiments of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0026] Figure 1 Schematic diagram of the process of wave packet separation based on sparse comb lattice described in an embodiment of the present invention;

[0027] Figure 2 Schematic diagram of the structure of a wave packet separation device based on a sparse comb lattice described in an embodiment of the present invention;

[0028] Figure 3 A schematic diagram of a signal excitation point and a signal receiving point in an embodiment of the present invention;

[0029] Figure 4 is a time domain diagram of an excitation signal in an embodiment of the present invention;

[0030] Figure 5 is a frequency domain diagram of an excitation signal in an embodiment of the present invention;

[0031] Figure 6 It is a cloud diagram distribution diagram of the waveguide structure in the frequency-wave number domain in an embodiment of the present invention;

[0032] Figure 7 is a dispersion curve diagram of the waveguide structure actually measured in an embodiment of the present invention;

[0033] Figure 8 A schematic diagram of a sparse comb receiving array of a sensor in an embodiment of the present invention;

[0034] Fig. 9is a time domain diagram of a received signal in an embodiment of the present invention;

[0035] Fig.10 is a frequency domain diagram of a received signal in an embodiment of the present invention;

[0036] Fig.11 Schematic diagram of time domain response of each mode in an embodiment of the present invention;

[0037] Fig.12 Schematic diagram of each mode echo situation in an embodiment of the present invention;

[0038] Fig.13 Schematic diagram of the waveguide structure of mode M3 in an embodiment of the present invention.

[0039] Markings in the figure: 800, wave packet separation device based on sparse comb lattice; 801, processor; 802, memory; 803, multimedia component; 804, I / O interface; 805, communication component. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0041] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings. At the same time, in the description of the present invention, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0042] Embodiment 1:

[0043] This embodiment provides a wave packet separation method based on a sparse comb lattice.

[0044] See also Figure 1 , the figure shows that the method includes step S100, step S200, step S300, step S400, step S500, and step 600.

[0045] Step S100: acquiring a time domain signal of a waveguide based on a plurality of signal receiving points, wherein the signal receiving points are evenly spaced on the waveguide structure to be monitored, and the relative position of each of the signal receiving points on the cross section of the waveguide structure is the same as the relative position of the signal excitation point on the cross section of the waveguide structure;

[0046] A series of signal receiving points are arranged at equal distances on the actual waveguide structure to be monitored, and the relative positions of the signal receiving points on the cross section are the same as the relative positions of the signal excitation points on the cross section. When the signal excitation point transmits a signal once, the signal receiving points at equal distances will sequentially receive the signal propagated by the waveguide in the waveguide structure.

[0047] Step S200: calculating dispersion information using the time domain signal;

[0048] The step S200 includes the following steps:

[0049] Converting the time domain signal into a frequency domain signal by Fourier transform;

[0050] Performing a second Fourier transform on the frequency domain signal to obtain a frequency-wave number domain signal;

[0051] Based on the frequency-wavenumber domain signal, obtaining a cloud map distribution of the waveguide structure in the frequency-wavenumber domain;

[0052] Based on the cloud map distribution, extract the wave number information at the extreme value of the wave number intensity at each frequency;

[0053] The wave number information at different frequencies is connected to obtain a dispersion curve, and the dispersion information is obtained through the dispersion curve.

[0054] In this embodiment, the signal obtained by each signal receiving point is a time domain signal, which can be converted into a frequency domain signal through Fourier transform.

[0055] The calculation formula of the frequency domain signal is:

[0056] ;

[0057] In the formula, Represents the matrix result of a Fourier transform, that is, the frequency domain signal, represents the total duration of the time-frequency signal, represents the time-frequency signal matrix composed of the signals at each signal receiving point, represents the time variable, represents the distance variable, represents an imaginary number, A vector of effective angular frequencies representing a time-frequency signal.

[0058] At the same time, the equidistant signal receiving points include the changes of the signal with the distance during the propagation process. The frequency-wavenumber domain signal can be obtained by the secondary Fourier transform of the series of frequency domain signals. The cloud map distribution of the propagation characteristics of the waveguide structure in the frequency-wavenumber domain can be obtained through the frequency-wavenumber domain signal.

[0059] The calculation formula of the frequency-wavenumber domain signal is:

[0060] ;

[0061] ;

[0062] In the formula, represents the matrix result of the second Fourier transform, that is, the frequency-wavenumber domain signal, express The transposed result of Represents the matrix result of a Fourier transform, that is, the frequency domain signal, represents the transpose operation, Represents the cycle, represents the distance variable, represents the effective wave number vector, Represents an imaginary number.

[0063] and The number of rows in the matrix is ​​equal to the number of time points. The number of matrix columns is equal to the number of signal receiving points. The number of rows in the matrix is ​​equal to the length of the frequency vector, The number of columns in the matrix is ​​equal to the length of the wavenumber vector.

[0064] After obtaining the frequency-wavenumber domain cloud map distribution of the measured waveguide structure, the wavenumber information at the extreme values ​​of the wavenumber intensity at each frequency is extracted in turn, and the dispersion curve can be obtained by connecting the wavenumber information at different frequencies, which describes the propagation characteristics of the waveguide structure.

[0065] Step S300: obtaining the total number of modes of the waveguide, the wave value values ​​of each mode at different angular frequencies and the length of the effective angular frequency vector, and calculating the optimal receiving point spacing of the sensor based on the total number of modes, the wave value values ​​and the length of the effective angular frequency vector;

[0066] In this embodiment, in order to obtain the best modal wave packet separation effect, it is necessary to calculate sensor arrangement parameter information such as the best receiving spacing of the sensors.

[0067] The optimal receiving point spacing can be determined by the waveform resolution principle. Therefore, the calculation formula for the optimal receiving point spacing is constructed by the total number of guided wave modes in the waveguide structure, the wave value of each mode at different angular frequencies, and the length of the effective angular frequency vector. The calculation formula for the optimal receiving point spacing is as follows:

[0068] ;

[0069] in, represents the optimal receiving point spacing, represents the total number of guided wave modes, represents the length of the effective angular frequency vector, Representing modality At angular frequency The wave value below, and denote the first constant parameter and the second constant parameter respectively, Indicates the modal index.

[0070] Step S400: setting sensor points according to the optimal receiving point spacing to obtain a sensor sparse comb receiving point array, wherein the sensor points are located at the signal receiving points;

[0071] The sensors are arranged according to the optimal receiving point spacing. The sensors are placed at the signal receiving points of the waveguide structure, and the number of sensors is arrive Generally, no more than 50.

[0072] Step S500: constructing a frequency response matrix based on the frequency dispersion information, calculating a frequency response vector based on the sparse comb receiving point matrix of the sensor, and calculating a total modal frequency amplitude coefficient in guided wave propagation based on the frequency response matrix and the frequency response vector;

[0073] The step S500 includes the following steps:

[0074] Based on the frequency dispersion information, construct a forward wave frequency response matrix and a reflected wave frequency response matrix;

[0075] constructing a frequency response matrix based on the forward wave frequency response matrix and the reflected wave frequency response matrix;

[0076] The expression of the frequency response matrix is:

[0077] ;

[0078] ;

[0079] ;

[0080] In the formula, Indicates angular frequency The forward wave frequency response matrix under Indicates angular frequency The reflected wave frequency response matrix is: Indicates angular frequency The frequency response matrix is: Representing modality At angular frequency The wave value below, , represents the modal index, represents the total number of guided wave modes, express The distance between the signal sensor point and the signal excitation point, , Indicates the point index. Indicates the total number of sensor points. Represents an imaginary number.

[0081] Based on the sparse comb-shaped receiving dot matrix of the sensor, a sensor point signal is obtained;

[0082] Performing Fourier transformation on the sensor point signals to calculate the frequency domain response of the signals at each sensor point during the guided wave propagation process;

[0083] Calculate a frequency response vector by using the signal frequency domain response;

[0084] The calculation formula of the frequency response vector is:

[0085] ;

[0086] ;

[0087] In the formula, Indicates angular frequency Down The signal frequency response at the sensor point is , Indicates the point index. represents the total duration of the time-frequency signal, represents the signal time history response, represents the time variable, represents an imaginary number, represents the angular frequency, Indicates angular frequency The frequency response vector is composed of the signal frequency responses of each sensor point.

[0088] Based on the frequency response matrix and the frequency response vector, the total modal frequency amplitude coefficient in the guided wave propagation is calculated by the waveguide propagation law and the pseudo-inverse algorithm, and the frequency amplitude coefficient includes the forward wave frequency amplitude coefficient and the reflected wave frequency amplitude coefficient.

[0089] To separate the time domain response of each mode, we must first determine the frequency amplitude coefficient of each mode. This coefficient can be solved by the waveguide propagation law combined with the pseudo-inverse algorithm. Therefore, the calculation formula for the total modal frequency amplitude coefficient is:

[0090] ;

[0091] ;

[0092] ;

[0093] In the formula, Indicates angular frequency The total modal frequency amplitude coefficient under , Indicates angular frequency The frequency response vector is composed of the signal frequency response of each sensor point. represents the pseudo-inverse matrix operation, Indicates angular frequency The frequency response matrix is: Indicates angular frequency The forward wave modal frequency amplitude coefficient under , Indicates angular frequency The reflected wave modal frequency amplitude coefficient under , Indicates angular frequency Lower mode The forward wave frequency amplitude coefficient, Indicates angular frequency Lower mode The reflected wave modal frequency amplitude coefficient, , represents the modal index, Represents the total number of modes of the guided wave.

[0094] Step S600: Based on the total modal frequency amplitude coefficient, the time domain response of each mode at different sensor points is obtained by inverse Fourier transform to complete wave packet separation.

[0095] Based on the total modal frequency amplitude coefficient, the time domain response of each mode at different sensor points is obtained by inverse Fourier transform, including:

[0096] Calculating a forward wave frequency response based on the forward wave frequency amplitude coefficient, and calculating a reflected wave frequency response based on the reflected wave frequency amplitude coefficient;

[0097] Calculate a forward wave frequency response vector based on the forward wave frequency response, and calculate a reflected wave frequency response vector based on the reflected wave frequency response;

[0098] Performing inverse Fourier transform on the forward wave frequency response vector and the reflected wave frequency response vector respectively to obtain a forward wave time domain signal and a reflected wave time domain signal;

[0099] The forward wave time domain signal and the reflected wave time domain signal are used together as the time domain responses of each mode at different sensor points.

[0100] In this embodiment, the frequency amplitude coefficient of the mode is combined with the frequency response factor of each mode to obtain the frequency domain response of different modes at each point. Further, the time domain response of each mode at different points can be obtained by inverse Fourier transform to achieve wave packet separation. The calculation formula of the time domain response is:

[0101] ;

[0102] ;

[0103] ;

[0104] ;

[0105] ;

[0106] ;

[0107] In the formula, Indicates angular frequency Down Sensor point mode The forward wave frequency response, Indicates angular frequency Down Sensor point mode The reflected wave frequency response, Representing modality At angular frequency The wave value below, express The distance between the signal sensor point and the signal excitation point, Indicates angular frequency Lower mode The forward wave frequency amplitude coefficient, Indicates angular frequency Lower mode The reflected wave modal frequency amplitude coefficient, represents an imaginary number, express Sensor point mode The forward wave frequency response vector, express Sensor point mode The reflected wave frequency response vector, Represents the angular frequency component Down Sensor point mode The forward wave frequency response, Represents the angular frequency component Down Sensor point mode The reflected wave frequency response, , represents the angular frequency component index, represents the total number of angular frequencies, express Sensor point mode The forward wave time domain signal, express Sensor point mode The reflected wave time domain signal, represents the time variable, Represents the angular frequency.

[0108] In this embodiment, the health monitoring of the waveguide structure can be performed by wave packet separation. A single point excitation and a sparse comb receiving array are set on the waveguide structure, and the received signal is processed by wave packet separation. When the waveguide structure is in a completely healthy state, the single point excited waveguide will not have a reflection effect. At this time, there is only a forward wave packet but no reflected wave packet. However, when the waveguide structure is damaged, the forward wave packet will generate a reflected echo when it encounters the damaged boundary.

[0109] The wave packet separation method based on sparse points can obtain the time domain response of the forward wave and the time domain response of the reflected wave of each mode. When the time domain response of the reflected wave appears, it can be determined that the waveguide structure is damaged. And because the distribution characteristics of the amplitude intensity of each mode are different, the position of the damage on the cross section of the waveguide structure can be determined according to the different response amplitudes of the reflected wave of each mode.

[0110] Embodiment 2:

[0111] This embodiment provides a wave packet separation device based on a sparse comb lattice, the device comprising:

[0112] A signal acquisition module, used for acquiring a time domain signal of the waveguide based on a plurality of signal receiving points, wherein the signal receiving points are evenly spaced on the waveguide structure to be monitored, and the relative position of each of the signal receiving points on the cross section of the waveguide structure is the same as the relative position of the signal excitation point on the cross section of the waveguide structure;

[0113] A first calculation module, used for calculating dispersion information through the time domain signal;

[0114] A second calculation module is used to obtain the total number of modes of the waveguide, the wave value of each mode at different angular frequencies and the length of the effective angular frequency vector, and calculate the optimal receiving point spacing of the sensor based on the total number of modes, the wave value and the length of the effective angular frequency vector;

[0115] A point setting module, used for setting sensor points according to the optimal receiving point spacing to obtain a sparse comb-shaped receiving dot matrix of the sensor, wherein the sensor points are located at the signal receiving points;

[0116] A third calculation module is used to construct a frequency response matrix based on the frequency dispersion information, calculate a frequency response vector based on the sparse comb receiving point matrix of the sensor, and calculate a total modal frequency amplitude coefficient in guided wave propagation based on the frequency response matrix and the frequency response vector;

[0117] The fourth calculation module is used to obtain the time domain response of each mode at different sensor points through inverse Fourier transform based on the total modal frequency amplitude coefficient to complete wave packet separation.

[0118] The first calculation module includes:

[0119] A first transform unit, configured to transform the time domain signal into a frequency domain signal by Fourier transform;

[0120] A second transform unit is used to perform a second Fourier transform on the frequency domain signal to obtain a frequency-wave number domain signal;

[0121] A first acquisition unit, configured to acquire a cloud map distribution of the waveguide structure in the frequency-wavenumber domain based on the frequency-wavenumber domain signal;

[0122] A second acquisition unit is used to extract the wave number information at the extreme value of the wave number intensity at each frequency based on the cloud map distribution;

[0123] The third acquisition unit is used to connect the wave number information at different frequencies to obtain a dispersion curve, and obtain the dispersion information through the dispersion curve.

[0124] The third calculation module includes:

[0125] A first construction unit is used to construct a forward wave frequency response matrix and a reflected wave frequency response matrix based on the dispersion information;

[0126] A second construction unit, configured to construct a frequency response matrix based on the forward wave frequency response matrix and the reflected wave frequency response matrix;

[0127] A fourth acquisition unit, configured to acquire a sensor point signal based on the sparse comb receiving dot matrix of the sensor;

[0128] A first calculation unit, used for performing Fourier transform on the sensor point signal to calculate the frequency domain response of the signal at each sensor point during the guided wave propagation process;

[0129] A second calculation unit, used for calculating a frequency response vector through the signal frequency domain response;

[0130] The third calculation unit is used to calculate the total modal frequency amplitude coefficient in the waveguide propagation based on the frequency response matrix and the frequency response vector, through the waveguide propagation law and the pseudo-inverse algorithm, and the frequency amplitude coefficient includes the forward wave frequency amplitude coefficient and the reflected wave frequency amplitude coefficient.

[0131] The fourth calculation module includes:

[0132] a fourth calculation unit, configured to calculate a forward wave frequency response based on the forward wave frequency amplitude coefficient, and calculate a reflected wave frequency response based on the reflected wave frequency amplitude coefficient;

[0133] a fifth calculation unit, configured to calculate a forward wave frequency response vector based on the forward wave frequency response, and calculate a reflected wave frequency response vector based on the reflected wave frequency response;

[0134] A third transformation unit is used to perform inverse Fourier transformation on the forward wave frequency response vector and the reflected wave frequency response vector to obtain a forward wave time domain signal and a reflected wave time domain signal;

[0135] The output unit is used to use the forward wave time domain signal and the reflected wave time domain signal together as the time domain response of each mode at different sensor points.

[0136] It should be noted that, regarding the device in the above embodiment, the specific manner in which each module performs the operation has been described in detail in the embodiment of the method, and will not be elaborated here.

[0137] Embodiment 3:

[0138] Corresponding to the above method embodiment, a wave packet separation device based on a sparse comb lattice is also provided in this embodiment. The wave packet separation device based on a sparse comb lattice described below and the wave packet separation method based on a sparse comb lattice described above can be referred to each other.

[0139] Figure 2 is a block diagram of a wave packet separation device 800 based on a sparse comb lattice according to an exemplary embodiment. Figure 2As shown, the wave packet separation device 800 based on sparse comb lattice may include: a processor 801 and a memory 802. The wave packet separation device 800 based on sparse comb lattice may also include one or more of a multimedia component 803, an I / O interface 804, and a communication component 805.

[0140] The processor 801 is used to control the overall operation of the sparse comb lattice-based wave packet separation device 800 to complete all or part of the steps in the above-mentioned sparse comb lattice-based wave packet separation method. The memory 802 is used to store various types of data to support the operation of the sparse comb lattice-based wave packet separation device 800, and these data may include, for example, instructions for any application or method operating on the sparse comb lattice-based wave packet separation device 800, as well as application-related data, such as contact data, sent and received messages, pictures, audio, video, etc. The memory 802 can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, disk or optical disk. The multimedia component 803 may include a screen and an audio component. The screen may be, for example, a touch screen, and the audio component is used to output and / or input audio signals. For example, the audio component may include a microphone for receiving external audio signals. The received audio signal may be further stored in the memory 802 or sent via the communication component 805. The audio component also includes at least one speaker for outputting audio signals. The I / O interface 804 provides an interface between the processor 801 and other interface modules, and the above-mentioned other interface modules can be keyboards, mice, buttons, etc. These buttons can be virtual buttons or physical buttons. The communication component 805 is used for wired or wireless communication between the wave packet separation device 800 based on sparse comb dot matrix and other devices. Wireless communication, such as Wi-Fi, Bluetooth, Near Field Communication (NFC), 2G, 3G or 4G, or a combination of one or more of them, so the corresponding communication component 805 can include: Wi-Fi module, Bluetooth module, NFC module.

[0141] In an exemplary embodiment, the wave packet separation device 800 based on a sparse comb lattice can be implemented by one or more application specific integrated circuits (Application Specific Integrated Circuit, referred to as ASIC), digital signal processors (Digital Signal Processing Device, referred to as DSP), digital signal processing devices (Digital Signal Processing Device, referred to as DSPD), programmable logic devices (Programmable Logic Device, referred to as PLD), field programmable gate arrays (Field Programmable Gate Array, referred to as FPGA), controllers, microcontrollers, microprocessors or other electronic components to perform the above-mentioned wave packet separation method based on a sparse comb lattice.

[0142] In another exemplary embodiment, a computer-readable storage medium including program instructions is also provided, and when the program instructions are executed by a processor, the steps of the above-mentioned wave packet separation method based on a sparse comb lattice are implemented. For example, the computer-readable storage medium can be the above-mentioned memory 802 including program instructions, and the above-mentioned program instructions can be executed by the processor 801 of the wave packet separation device 800 based on a sparse comb lattice to complete the above-mentioned wave packet separation method based on a sparse comb lattice.

[0143] Embodiment 4:

[0144] This embodiment adopts single-point excitation. The point of single-point excitation is selected at the upper half of the rail waist, and a series of signal receiving points are set at the same point on the cross section. The node spacing is 5mm, and the number of nodes is 1000. Figure 3 As shown in the figure, the single-point excitation is located on a certain section of the waveguide structure, and the series of signal receiving points are not in the same section as the single-point excitation, but their relative positions in their respective sections are the same. The excitation signal is a 10-cycle Hanning window function signal with a center frequency of 15kHz. The time domain and frequency domain of the signal are shown in Figure 4 and Figure 5 shown.

[0145] The frequency-wavenumber domain cloud distribution diagram of the measured waveguide structure is obtained by two-dimensional Fourier transform, such as Figure 6 Then, the wave number information at the extreme value of the wave number intensity at each frequency is extracted in turn, and the dispersion curve can be obtained by connecting the wave number information at different frequencies, as shown in Figure 7 shown.

[0146] Calculate the optimal receiving point spacing of the sensor , 4cm, and it can be seen from the dispersion curve that there are only four curves, which means that there are only four propagation modes in the waveguide structure. Therefore, the number of receiving sensors can be 8 to 16. In this embodiment, the number of sensors is 10, and the sensor sparse comb receiving dot array is as follows: Figure 8 shown.

[0147] Input a 20-cycle 15kHz center frequency Hanning window function signal at the signal excitation point. The time domain and frequency domain of the received signal are as follows: Fig. 9 and Fig.10 As shown. By separating the wave packets of the sparse comb lattice, the responses of each mode of the received sensor signal can be obtained, as shown in Fig.11 As shown. Fig.11 The wave packet responses of the four modes can be clearly seen in the figure. The four modes are M3, M5, M6 and M9.

[0148] When damage occurs in different parts of the rail, the location of the damage can be determined based on the echo effect of each modal wave packet. Fig.12 The echo conditions of each mode under a damage condition are given in FIG. 1 , among which only mode M3 has an obvious wave packet echo. Therefore, according to the wave structure of mode M3, Fig.13 As shown, it is determined that the waist of the rail is damaged, thus realizing the damage monitoring of the rail.

[0149] Therefore, the present invention can obtain the precise dispersion information of the waveguide structure through the measured signal, and then construct the frequency response matrix of the waveguide structure, and finally realize the wave mode separation based on the sparse comb lattice, avoiding the error of the semi-analytical finite element method, and can separate the single wave packet of each mode through the frequency response matrix when there are very few signal receiving points, which makes up for the defects of the traditional wave packet separation method, solves the difficulty of separating the guided wave packets based on sparse points, and lays the foundation for the health monitoring of the waveguide structure.

[0150] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

[0151] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A wave packet separation method based on sparse comb lattice, characterized in that: include: Acquire a time domain signal of the waveguide based on a plurality of signal receiving points, wherein the signal receiving points are evenly spaced on the waveguide structure to be monitored, and the relative position of each of the signal receiving points on the cross section of the waveguide structure is the same as the relative position of the signal excitation point on the cross section of the waveguide structure; Calculating dispersion information through the time domain signal; Obtaining the total number of modes of the waveguide, the wave value values ​​of each mode at different angular frequencies and the length of the effective angular frequency vector, and calculating the optimal receiving point spacing of the sensor based on the total number of modes, the wave value values ​​and the length of the effective angular frequency vector; The sensor points are set by the optimal receiving point spacing to obtain a sparse comb-shaped receiving point array of the sensor, and the sensor points are located at the signal receiving points; Based on the frequency dispersion information, a frequency response matrix is ​​constructed, based on the sparse comb receiving point matrix of the sensor, a frequency response vector is calculated, and based on the frequency response matrix and the frequency response vector, a total modal frequency amplitude coefficient in the guided wave propagation is calculated; Based on the total modal frequency amplitude coefficient, the time domain response of each mode at different sensor points is obtained by inverse Fourier transform to complete wave packet separation; The calculating of the dispersion information by the time domain signal includes: Converting the time domain signal into a frequency domain signal by Fourier transform; Performing a second Fourier transform on the frequency domain signal to obtain a frequency-wave number domain signal; Based on the frequency-wavenumber domain signal, obtaining a cloud map distribution of the waveguide structure in the frequency-wavenumber domain; Based on the cloud map distribution, extract the wave number information at the extreme value of the wave number intensity at each frequency; The wave number information at different frequencies is connected to obtain a dispersion curve, and the dispersion information is obtained through the dispersion curve.

2. The wave packet separation method based on sparse comb lattice according to claim 1, characterized in that Based on the frequency dispersion information, a frequency response matrix is ​​constructed, and based on the sparse comb receiving lattice of the sensor, a frequency response vector is calculated, including: Based on the frequency dispersion information, construct a forward wave frequency response matrix and a reflected wave frequency response matrix; constructing a frequency response matrix based on the forward wave frequency response matrix and the reflected wave frequency response matrix; Based on the sparse comb-shaped receiving dot matrix of the sensor, a sensor point signal is obtained; Performing Fourier transformation on the sensor point signals to calculate the frequency domain response of the signals at each sensor point during the guided wave propagation process; A frequency response vector is calculated using the signal frequency domain response.

3. The wave packet separation method based on sparse comb lattice according to claim 1, characterized in that , based on the frequency response matrix and the frequency response vector, calculating the total modal frequency amplitude coefficient in the guided wave propagation, including: Based on the frequency response matrix and the frequency response vector, the total modal frequency amplitude coefficient in the guided wave propagation is calculated by the waveguide propagation law and the pseudo-inverse algorithm, and the frequency amplitude coefficient includes the forward wave frequency amplitude coefficient and the reflected wave frequency amplitude coefficient.

4. The wave packet separation method based on sparse comb lattice according to claim 3 is characterized in that ,Based on the total modal frequency amplitude coefficient, the time domain response of each mode at different sensor points is obtained by inverse Fourier transform, including: Calculating a forward wave frequency response based on the forward wave frequency amplitude coefficient, and calculating a reflected wave frequency response based on the reflected wave frequency amplitude coefficient; Calculate a forward wave frequency response vector based on the forward wave frequency response, and calculate a reflected wave frequency response vector based on the reflected wave frequency response; Performing inverse Fourier transform on the forward wave frequency response vector and the reflected wave frequency response vector respectively to obtain a forward wave time domain signal and a reflected wave time domain signal; The forward wave time domain signal and the reflected wave time domain signal are used together as the time domain responses of each mode at different sensor points.

5. A wave packet separation device based on a sparse comb lattice, characterized in that: include: A signal acquisition module, used for acquiring a time domain signal of the waveguide based on a plurality of signal receiving points, wherein the signal receiving points are evenly spaced on the waveguide structure to be monitored, and the relative position of each of the signal receiving points on the cross section of the waveguide structure is the same as the relative position of the signal excitation point on the cross section of the waveguide structure; A first calculation module, used for calculating dispersion information through the time domain signal; A second calculation module is used to obtain the total number of modes of the waveguide, the wave value of each mode at different angular frequencies and the length of the effective angular frequency vector, and calculate the optimal receiving point spacing of the sensor based on the total number of modes, the wave value and the length of the effective angular frequency vector; A point setting module, used for setting sensor points according to the optimal receiving point spacing to obtain a sparse comb-shaped receiving dot matrix of the sensor, wherein the sensor points are located at the signal receiving points; A third calculation module is used to construct a frequency response matrix based on the frequency dispersion information, calculate a frequency response vector based on the sparse comb receiving point matrix of the sensor, and calculate a total modal frequency amplitude coefficient in guided wave propagation based on the frequency response matrix and the frequency response vector; A fourth calculation module is used to obtain the time domain response of each mode at different sensor points through inverse Fourier transform based on the total modal frequency amplitude coefficient to complete wave packet separation; The first calculation module includes: A first transform unit, configured to transform the time domain signal into a frequency domain signal by Fourier transform; A second transform unit is used to perform a second Fourier transform on the frequency domain signal to obtain a frequency-wave number domain signal; A first acquisition unit, configured to acquire a cloud map distribution of the waveguide structure in the frequency-wavenumber domain based on the frequency-wavenumber domain signal; A second acquisition unit is used to extract the wave number information at the extreme value of the wave number intensity at each frequency based on the cloud map distribution; The third acquisition unit is used to connect the wave number information at different frequencies to obtain a dispersion curve, and obtain the dispersion information through the dispersion curve.

6. The wave packet separation device based on sparse comb lattice according to claim 5, characterized in that: The third calculation module includes: A first construction unit, configured to construct a forward wave frequency response matrix and a reflected wave frequency response matrix based on the frequency dispersion information; A second construction unit, configured to construct a frequency response matrix based on the forward wave frequency response matrix and the reflected wave frequency response matrix; A fourth acquisition unit, configured to acquire a sensor point signal based on the sparse comb receiving dot matrix of the sensor; A first calculation unit, used for performing Fourier transform on the sensor point signal to calculate the frequency domain response of the signal at each sensor point during the guided wave propagation process; A second calculation unit, used for calculating a frequency response vector through the signal frequency domain response; The third calculation unit is used to calculate the total modal frequency amplitude coefficient in the waveguide propagation based on the frequency response matrix and the frequency response vector, through the waveguide propagation law and the pseudo-inverse algorithm, and the frequency amplitude coefficient includes the forward wave frequency amplitude coefficient and the reflected wave frequency amplitude coefficient.

7. The wave packet separation device based on sparse comb lattice according to claim 6, characterized in that: The fourth calculation module includes: a fourth calculation unit, configured to calculate a forward wave frequency response based on the forward wave frequency amplitude coefficient, and calculate a reflected wave frequency response based on the reflected wave frequency amplitude coefficient; a fifth calculation unit, configured to calculate a forward wave frequency response vector based on the forward wave frequency response, and calculate a reflected wave frequency response vector based on the reflected wave frequency response; A third transformation unit is used to perform inverse Fourier transformation on the forward wave frequency response vector and the reflected wave frequency response vector to obtain a forward wave time domain signal and a reflected wave time domain signal; The output unit is used to use the forward wave time domain signal and the reflected wave time domain signal together as the time domain response of each mode at different sensor points.

8. A wave packet separation device based on a sparse comb lattice, characterized in that: include: Memory for storing computer programs; A processor, configured to implement the steps of the wave packet separation method based on a sparse comb lattice as claimed in any one of claims 1 to 4 when executing the computer program.

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