A damage detection method based on sparse wing array modulated phase map spectral method

Abstract

The application discloses a damage detection method based on a sparse wing array frequency modulation spectrum phase mapping method, and belongs to the technical field of crack detection. The method comprises the following steps: emitting a linear sweep wave and receiving a return wave; processing the return wave by using a spectrum phase mapping method. The main process of the spectrum phase mapping method comprises twin product transformation and Fourier transformation. The frequency difference between the sweep wave and the return wave can be obtained accurately, so that the distance from the damage to a sweep wave transceiving assembly can be calculated. The sweep wave transceiving assembly, namely a sparse wing array receiving device, is used for accurately positioning the damage. The device can firstly roughly determine the target direction, and then accurately position the damage crack according to a pair of receivers. The application can effectively improve the amplitude of the return wave signal, so that more accurate distance and position can be obtained, and the practicability is high.

Description

Technical Field

[0001] This invention relates to the field of crack detection technology, specifically to a damage detection method based on the sparse wing array modulated phase diagram method. Background Technology

[0002] Plate-shaped and tubular structural components have wide applications in numerous industrial and scientific research fields, such as aerospace, rail transportation, and petrochemicals. In these fields, the safety and reliability of these components are crucial for the protection of personnel and assets. However, these structural components often suffer damage, such as weld joint defects, cracks in bolted areas, cracks caused by external forces, corrosion, and wear. This damage can lead to structural failure, seriously threatening the safe operation of equipment and the lives of personnel. Therefore, damage detection of plate-shaped and tubular structural components is essential during production and use. Traditional damage detection methods typically rely on manual visual or tactile inspection, or the use of non-destructive testing techniques such as magnetic particle testing and eddy current testing. However, these methods not only have drawbacks such as high material quality requirements, high operational difficulty, and low efficiency, but also cannot accurately detect hidden defects such as microcracks, thus failing to meet the high precision and efficiency requirements of modern industry for damage detection. Based on the above defects and shortcomings, we propose a train bogie damage detection method based on the sparse wing array modulated phase diagram method for crack detection in plate-shaped and tubular target components. Summary of the Invention

[0003] The technical problem to be solved by this invention is to enable better detection of micro-cracks.

[0004] The technical solution adopted by this invention to solve the technical problem is as follows: a damage detection method based on the sparse wing array modulated phase map method, comprising the following steps:

[0005] S1: Emit a linear sweep frequency wave and receive the echo. Place a sweep frequency wave transceiver near the target location of the crack in the target part. Use the sweep frequency wave transceiver to emit a linear sweep frequency wave according to the linear frequency modulation pulse signal and receive the echo to generate an echo signal. The frequency of the emitted linear frequency modulation pulse signal changes linearly.

[0006] S2: The echo is processed using the phase spectrum method to calculate the distance from the damage point at the crack target location to the swept-frequency transceiver component. The transmitted linear frequency modulated pulse signal and the received echo signal are processed using the twin product transform method to obtain a transformed wave. The transformed wave is a fixed-frequency signal. The real part of the transformed wave is obtained using Euler's formula. The real part is then subjected to Fourier transform to obtain the processed wave. The distance is then calculated from the processed wave.

[0007] S3: The frequency sweep transceiver assembly includes a sparse wing array transceiver device. The sparse wing array transceiver device is used for signal transmission and reception to accurately locate damage. The sparse wing array transceiver device is a linear array transceiver device. The sparse wing array transceiver device includes a transceiver mechanism and a fixed-point rotation mechanism. The transceiver mechanism includes three sensors arranged linearly and equally spaced. The sensor located at the center is a transceiver used to transmit a linear frequency sweep wave and receive the echo. The other two sensors are receivers used to receive the echo. The fixed-point rotation mechanism is driven by the three sensors to drive the three sensors to rotate around a fixed point of the fixed-point rotation mechanism to adjust the transmission and reception direction. The line connecting the three sensors is tangent to the arc formed by the fixed-point rotation mechanism driving the three sensors to rotate.

[0008] S3.1: Place the sparse wing array transceiver device near the crack target location, and continuously adjust the rotation angle of the transceiver mechanism using the spectral phase diagram method described in S2. Measure multiple distances using the transceiver located in the middle of the transceiver mechanism, and record the minimum value and corresponding fuzzy position among the multiple distances. The transceiver measures the distance by generating a linear sweep wave and receiving echoes.

[0009] S3.2: Place the sparse wing array transceiver near the fuzzy position. Near the fuzzy position, determine the fixed position of the fixed-point rotation mechanism and the initial reference line corresponding to the fixed position. Rotate the sparse wing array transceiver around the fixed point. The transceiver generates a linear sweep frequency wave. Receive multiple echo signals using the two receivers of the transceiver mechanism in the sparse wing array transceiver. Determine the distance from the two receivers to the crack target position based on the echo signals received by the two receivers. When the distances from the two receivers to the crack target position are consistent, determine the deflection angle of the transceiver mechanism relative to the initial reference line corresponding to the fixed point.

[0010] S3.3: Using the spectral diagram method described in S2, the damage distance is determined by measuring the distance using the transceiver located in the middle position of the transceiver mechanism, and the precise location of the crack target position is obtained based on the deflection angle and the damage distance.

[0011] In a preferred embodiment of the present invention, the two receivers determine whether they are at the same location as the crack target based on the time difference of the received echo signals. At any given time, the time difference between the received echo signals is Δt. For any σ > 0, |Δt| < σ. The number of receivers is N, where N is an even number and N ≥ 2. Increasing the number of receivers N improves the accuracy of the positioning. Using the transceiver as a reference, the receivers located on either side of the transceiver are designated as the i-th receiver from closest to furthest. The time difference between two symmetrical receivers is Δt. i The weight corresponding to each time difference is α. i , Where n is half the number of receivers on both sides of the transceiver.

[0012] In a preferred embodiment of the present invention, the linear frequency modulated pulse signal is W(t) with frequency f(t), where f(t) = f0 + K. t , The echo signal is R(t).

[0013] As a preferred embodiment of the present invention, the transformed wave is m(t). Using Euler's formula to obtain the real part of m(t), a Fourier transform is performed on the real part to obtain the frequency domain expression of the processed wave M(t), which is: Where ω0 and Given that ω is a constant, the frequency difference between the emitted sweep wave and the echo is Δω = ω0. Based on the formula: The distance between the swept-frequency transceiver component and the target location of the crack is obtained.

[0014] As a preferred embodiment of the present invention, the sparse wing array transceiver device is placed near the target crack location. Using the spectral phase diagram method described in S2, the rotation angle of the transceiver mechanism is continuously adjusted. Multiple distances are measured using the transceiver located in the middle of the transceiver mechanism, and the minimum value among these distances and the corresponding fuzzy position are recorded. The minimum value is d. min The corresponding fuzzy position is θ about θ about ~d min =min(d1,d2,d3,d4,……d n ).

[0015] As a preferred embodiment of the present invention, the sparse wing array transceiver is placed near an ambiguous position. Near this ambiguous position, the fixed-point position of the fixed-point rotation mechanism and the corresponding initial reference line are determined. The sparse wing array transceiver rotates around the fixed point, generating a linear frequency sweep wave. Multiple echo signals are received using two receivers in the transceiver mechanism of the sparse wing array transceiver. The distance from the two receivers to the crack target position is determined based on the echo signals received by the two receivers. The distance determined by the receiver located on one side is d. l1 The distance determined by the receiver located on the other side is d. r1 When the two receivers are aligned with the target location of the crack, i.e., d l1 =d r1 The deflection angle of the transceiver mechanism relative to the initial baseline corresponding to the fixed point is recorded as the perfect position, and the deflection angle is θ. perfect .

[0016] As a preferred embodiment of the present invention, the damage distance is determined by measuring the distance using a transceiver located in the middle position of the transceiver mechanism, where the damage distance is d. final Based on the deflection angle and damage distance, the precise location of the crack target is obtained, and the precise location is L(θ). perfect ,d final ).

[0017] The beneficial effects of this invention are reflected in:

[0018] 1. A transceiver is set up to generate a linear frequency sweep wave and receive the echo. A receiver is set up to receive the echo. The echo is processed using the spectral phase diagram method to calculate the distance from the damage point of the crack target location to the receiver. By first measuring the distance multiple times, an ambiguous location is determined. Then, the sparse wing array transceiver is moved to the ambiguous location and measured again to obtain the precise location of the crack target. By increasing the amplitude of the echo signal, the location of the crack target can be located more accurately. Attached Figure Description

[0019] Figure 1 A schematic diagram of a linear sweep frequency excitation signal;

[0020] Figure 2 A schematic diagram of a linearly swept frequency wave reflection signal.

[0021] Figure 3 A schematic diagram of the spectrum of a linear frequency sweep wave for the excitation signal;

[0022] Figure 4A schematic diagram showing the result of the twin product transformation;

[0023] Figure 5 This is a schematic diagram of the result of the Fourier transform.

[0024] Figure 6 A schematic diagram of the initial state for accurate damage localization of a sparse wing array transceiver model;

[0025] Figure 7 A schematic diagram of a sparse-wing array transceiver model under rotational conditions for precise damage localization.

[0026] Figure 8 A schematic diagram of an extended model for a sparse wing array transceiver device. Detailed Implementation

[0027] The invention will now be described in further detail with reference to the accompanying drawings.

[0028] Combined with appendix Figure 1-8 As shown, a damage detection method based on the sparse wing array modulated phase map method is characterized by the following steps:

[0029] S1: Emit a linear sweep frequency wave and receive the echo. Place a sweep frequency wave transceiver near the target location of the crack in the target part. Use the sweep frequency wave transceiver to emit a linear sweep frequency wave according to the linear frequency modulation pulse signal and receive the echo to generate an echo signal. The frequency of the emitted linear frequency modulation pulse signal changes linearly.

[0030] Preferably, the linear frequency modulated pulse signal is W(t) with a frequency of f(t), where f(t) = f0 + K. t , The echo signal is R(t). The target parts are plate-shaped or tubular metal parts. Since the pulse used is linearly varying, if it is a single-frequency pulse, the reflected signal of the metal crack is small; if it is a multi-frequency pulse, the reflected signal amplitude is large. Compared with traditional guided wave and bulk wave metal flaw detection methods, it is more conducive to detecting small cracks and minor damage, and the positioning is more accurate. At the same time, the target parts can also be plate-shaped or tubular non-metallic parts, and the pulse frequency used is selected according to the specific material of the target parts.

[0031] S2: The echo is processed using the phase spectrum method to calculate the distance from the damage point at the crack target location to the swept-frequency transceiver component. The transmitted linear frequency modulated pulse signal and the received echo signal are processed using the twin product transform method to obtain a transformed wave. The transformed wave is a fixed-frequency signal. The real part of the transformed wave is obtained using Euler's formula. The real part is then subjected to a Fourier transform to obtain the processed wave. The distance is then calculated from the processed wave. Because the twin product transform is used, the echo amplitude is ensured to be large while converting the two frequency modulated signals with a certain time delay, the excitation linear frequency modulated pulse signal and the echo signal, into fixed-frequency signals, which facilitates the subsequent Fourier transform.

[0032] Preferably, the transformed wave is m(t). Using Euler's formula to obtain the real part of m(t), a Fourier transform is performed on the real part to obtain the frequency domain expression of the processed wave M(t), which is: Where ω0 and Given that ω is a constant, the frequency difference between the emitted sweep wave and the echo is Δω = ω0. Based on the formula: The distance between the swept-frequency transceiver component and the target location of the crack is obtained.

[0033] It should be further explained that the spectral phase diagram method is a precise ranging method. First, the echo signal and the excitation linear frequency modulated pulse signal are processed by twin product transform. Then, this fixed-frequency signal is subjected to Fourier transform to obtain its frequency domain expression, i.e. A more accurate frequency difference can then be obtained, based on It can determine a relatively accurate distance.

[0034] S3: The frequency sweep transceiver assembly includes a sparse wing array transceiver device. The sparse wing array transceiver device is used for signal transmission and reception to accurately locate damage. The sparse wing array transceiver device is a linear array transceiver device. The sparse wing array transceiver device includes a transceiver mechanism and a fixed-point rotation mechanism. The transceiver mechanism includes three sensors arranged linearly and equally spaced. The sensor located at the center is a transceiver used to transmit a linear frequency sweep wave and receive the echo. The other two sensors are receivers used to receive the echo. The fixed-point rotation mechanism is driven by the three sensors to drive the three sensors to rotate around a fixed point of the fixed-point rotation mechanism to adjust the transmission and reception direction. The line connecting the three sensors is tangent to the arc formed by the fixed-point rotation mechanism driving the three sensors to rotate.

[0035] S3.1: Place the sparse wing array transceiver near the crack target location, and continuously adjust the rotation angle of the transceiver mechanism using the spectral phase diagram method described in S2. The adjustment of the rotation angle is very small. Measure multiple distances using the transceiver located in the middle position of the transceiver mechanism, and record the minimum value of the multiple distances and the corresponding fuzzy position. The transceiver measures the distance by generating a linear sweep wave and receiving the echo.

[0036] Preferably, the sparse wing array transceiver is placed near the target crack location. Using the spectral mapping method described in S2, the rotation angle of the transceiver mechanism is continuously adjusted. Multiple distances are measured using the transceiver located in the middle of the transceiver mechanism, and the minimum value of these distances and its corresponding fuzzy position are recorded. The minimum value is d. min The corresponding fuzzy position is θ about θ about ~d min =min(d1,d2,d3,d4,……d n By using the above methods, the location range of the crack target can be significantly narrowed, laying the foundation for subsequent precise positioning;

[0037] S3.2: Place the sparse wing array transceiver near the fuzzy position. Near the fuzzy position, determine the fixed position of the fixed-point rotation mechanism and the initial reference line corresponding to the fixed position. Rotate the sparse wing array transceiver around the fixed point. The transceiver generates a linear sweep frequency wave. Receive multiple echo signals using the two receivers of the transceiver mechanism in the sparse wing array transceiver. Determine the distance from the two receivers to the crack target position based on the echo signals received by the two receivers. When the distances from the two receivers to the crack target position are consistent, determine the deflection angle of the transceiver mechanism relative to the initial reference line corresponding to the fixed point.

[0038] Preferably, the sparse wing array transceiver is placed near the ambiguity position. Near this ambiguity position, the fixed-point position of the fixed-point rotation mechanism and the corresponding initial reference line are determined. The sparse wing array transceiver rotates around the fixed point, generating a linear frequency sweep wave. Multiple echo signals are received using the two receivers in the transceiver mechanism of the sparse wing array transceiver. The distance from the two receivers to the crack target position is determined based on the echo signals received by the two receivers. The distance determined by the receiver located on one side is d. l1 The distance determined by the receiver located on the other side is d. r1 When the two receivers are aligned with the target location of the crack, i.e., d l1 =d r1The deflection angle of the transceiver mechanism relative to the initial baseline corresponding to the fixed point is recorded as the perfect position, and the deflection angle is θ. perfect ;

[0039] S3.3: Using the spectral phase diagram method described in S2, the damage distance is determined by measuring the distance using the transceiver located in the middle position of the transceiver mechanism, and the precise location of the crack target position is obtained based on the deflection angle and the damage distance.

[0040] Preferably, the damage distance is determined by measuring the distance using the transceiver located in the middle position of the transceiver mechanism, where the damage distance is d. fianl Based on the deflection angle and damage distance, the precise location of the crack target is obtained, and the precise location is L(θ). perfect ,d final By using a transceiver located in the center in combination with receivers on both sides, the target location of the crack can be accurately located.

[0041] Furthermore, the two receivers determine whether they are at the same location as the crack target based on the time difference of the received echo signals. At any given time, the time difference between the two receivers receiving the echo signals is Δt. For any σ > 0, |Δt| < σ. The number of receivers is N, where N is an even number and N ≥ 2. Increasing the number of receivers N improves the accuracy of positioning. Taking the transceiver as a reference, the receivers located on both sides of the transceiver are numbered i from near to far. The time difference between two symmetrical receivers is Δt. i The weight corresponding to each time difference is α. i , Where n is half the number of receivers on both sides of the transceiver. Receivers closer to the transceiver at the center have smaller time difference errors in receiving echoes, and therefore receive larger weights. The weight α is generated using the geometric weighting method. i It is the first item The common ratio is By using a geometric sequence and increasing the number of receivers, combined with a geometric weighting method, the target location of the crack can be located more accurately, reducing errors.

[0042] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A method for damage detection based on sparse wing array frequency-modulated spectrum pattern method, characterized in that: The method comprises the following steps: S1: emitting a linear sweep wave, receiving a return wave, placing a sweep wave transceiver assembly near a crack target position of a target object, emitting a linear sweep wave according to a linear frequency modulation pulse signal by using the sweep wave transceiver assembly, and receiving a return wave to generate a return wave signal, the frequency of the emitted linear frequency modulation pulse signal being linearly changed; S2: processing the return wave by using a spectrum phase spectrum method, calculating the distance from the crack target position to the sweep wave transceiver assembly, processing the emitted linear frequency modulation pulse signal and the received return wave signal by using a twin product transformation method to obtain a transformed wave, the transformed wave being a fixed frequency signal, obtaining the real part of the transformed wave by using an Euler formula, performing Fourier transform on the real part to obtain a processed wave, and then calculating the processed wave to obtain the distance; S3: the sweep wave transceiver assembly comprises a sparse wing array transceiver device, the signal is received and transmitted by using the sparse wing array transceiver device to accurately position the damage, the sparse wing array transceiver device is a linear array transceiver device, the sparse wing array transceiver device comprises a transceiving mechanism and a fixed-point rotating mechanism, the transceiving mechanism comprises three sensors, the three sensors are linearly and equidistantly arranged, the sensor at the center position is a transceiver, the transceiver is used for emitting a linear sweep wave and receiving a return wave, the other two sensors are receivers, the receivers are used for receiving a return wave, the fixed-point rotating mechanism is drivingly connected with the three sensors and is used for driving the three sensors to rotate around the fixed-point rotating mechanism to adjust the transceiving direction, the line connecting the three sensors is tangent to the arc formed by the rotation of the three sensors driven by the fixed-point rotating mechanism; S3.1: placing the sparse wing array transceiver device near the crack target position, continuously adjusting the rotation angle of the transceiving mechanism by using the spectrum phase spectrum method in S2, measuring a plurality of distances by using the transceiver in the middle position of the transceiving mechanism, and recording the minimum value in the plurality of distances and the corresponding ambiguous position, the transceiver measures the distance by generating a linear sweep wave and receiving a return wave; S3.2: placing the sparse wing array transceiver device near the ambiguous position, determining the fixed-point position of the fixed-point rotating mechanism and the initial reference line corresponding to the fixed-point position near the ambiguous position, rotating the transceiver around the fixed point by means of the sparse wing array transceiver device, the transceiver generates a linear sweep wave, and the two receivers of the transceiving mechanism in the sparse wing array transceiver device receive a plurality of return wave signals, the distances from the two receivers to the crack target position are determined according to the return wave signals received by the two receivers, and when the distances from the two receivers to the crack target position are consistent, the deflection angle of the transceiving mechanism relative to the initial reference line corresponding to the fixed point is determined; S3.3: determining the damage distance by measuring the distance by using the transceiver in the middle position of the transceiving mechanism by means of the spectrum phase spectrum method in S2, and obtaining the accurate positioning of the crack target position according to the deflection angle and the damage distance.

2. The damage detection method based on sparse wing array frequency-modulated spectrum pattern method according to claim 1, characterized in that: The chirp signal is W(t), the frequency is f(t), f(t)=f0+K t , The echo signal is R(t), 3. The damage detection method based on sparse wing array frequency-modulated spectrum pattern method according to claim 2, characterized in that: The transform wave is m(t), the real part of m(t) is obtained by Euler formula, the Fourier transform is performed on the real part to obtain a frequency domain expression of the processing wave M(t), and the expression is where ω0 and are constants, a frequency difference of the emitted sweep wave and the echo is Δω=ω0, and according to the formula: A distance of the sweep wave transceiving assembly from the crack target position is obtained 4. The damage detection method based on sparse wing array frequency-modulated spectrum pattern method according to claim 3, characterized in that: Placing the sparse wing array transceiver device near the crack target position, using the spectral phase spectroscopy method in S2, constantly adjusting the rotation angle of the transceiver mechanism, measuring multiple distances using the transceiver in the middle position of the transceiver mechanism, and recording the minimum value and the corresponding ambiguous position in the multiple distances, the minimum value is d min , and the corresponding ambiguous position is θ about . about θ min ~ d n = min(d1, d2, d3, d4, … d 5. The damage detection method based on sparse wing array frequency-modulated spectrum pattern method according to claim 4, characterized in that: The sparse wing array transceiver device is placed near the ambiguous position, the fixed point position of the fixed point rotating mechanism and the initial reference line corresponding to the fixed point position are determined, the rotating mechanism is rotated around the fixed point by means of the sparse wing array transceiver device, the transceiver generates a linear sweep wave, and multiple echo signals are received by two receivers of the rotating mechanism in the sparse wing array transceiver device, the distances from the two receivers to the crack target position are determined according to the echo signals received by the two receivers, the distance determined by the receiver on one side is d l1 , the distance determined by the receiver on the other side is d r1 , when the distances from the two receivers to the crack target position are consistent, that is, d l1 =d r1 , the deflection angle of the rotating mechanism relative to the initial reference line corresponding to the fixed point at this time is recorded as the perfect position, and the deflection angle is θ perfect .

6. The damage detection method based on sparse wing array frequency-modulated spectrum pattern method according to claim 5, characterized in that: The distance measurement is performed by using the transceiver located in the middle position of the transceiver mechanism to determine the damage distance d fianl , and the accurate positioning L(θ perfect ,d final ) of the crack target position is obtained according to the deflection angle and the damage distance.

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