Elastic wave radar detection device and method

Abstract

The present invention provides an elastic wave radar detection device and method, the device comprising: an excitation device, a first sensor, a second sensor and a controller, the first sensor is arranged on the excitation device, the second sensor is arranged on the object to be measured, the first sensor is used to collect excitation information, that is, incident signal, the second sensor is used to collect information of the object to be measured, that is, vibration signal, the first sensor and the second sensor are both connected to the controller. The elastic wave radar detection device and method provided by the present invention can receive excitation information, introduce standard incident signal, realize signal uniformity, and improve detection accuracy.

Description

Technical Field

[0001] The present invention relates to the technical field of civil engineering, and in particular to an elastic wave radar detection device and method. Background Art

[0002] At present, the tapping method is mainly used to detect structural debonding using elastic waves. However, the tapping method does not record the information of the excitation itself. Therefore, the excitation device, strength, and excitation position will cause the elastic wave morphology received each time to be different during actual detection, that is, the homogeneity of the received vibration signal is poor, which directly affects the detection result. Therefore, it is very necessary to design an elastic wave radar detection device and method. Summary of the invention

[0003] The purpose of the present invention is to provide an elastic wave radar detection device and method, which can receive excitation information, introduce a standard incident signal, achieve signal uniformity, and improve detection accuracy.

[0004] To achieve the above object, the present invention provides the following solutions:

[0005] An elastic wave radar detection device includes: an excitation device, a first sensor, a second sensor and a controller, wherein the first sensor is arranged on the excitation device, and the second sensor is arranged on the object to be measured. The first sensor is used to collect excitation information, i.e., an incident signal, and the second sensor is used to collect information of the object to be measured, i.e., a vibration signal. The first sensor and the second sensor are both connected to the controller.

[0006] Optionally, the excitation device is an excitation hammer, which includes a handle and an arc-shaped hammer head, the handle is fixedly connected to the arc-shaped hammer head, the first sensor is fixedly arranged on the arc-shaped hammer head, and the direction of the first sensor is perpendicular to the arc surface of the arc-shaped hammer head contacting the ground.

[0007] Optionally, the excitation device is an excitation rod, which includes a rod body, a connecting member and a hammer head, one end of the rod body is provided with a first thread, one end of the connecting member is provided with a first screw hole corresponding to the first thread, the connecting member is fixedly set on the rod body through the first thread and the first screw hole, the other end of the connecting member is provided with a second screw hole, one end of the hammer head is provided with a second thread corresponding to the second screw hole, the hammer head is fixedly set on the connecting member through the second thread and the second screw hole, the other end of the hammer head is provided with an arc surface for contacting the object to be measured, the first sensor is fixedly set inside the rod body or the connecting member, and the direction of the first sensor is consistent with the direction of the axis of the rod body.

[0008] The present invention also provides an elastic wave radar detection method, which is applied to the elastic wave radar detection device, and comprises the following steps:

[0009] Step 1: Use a vibration device to knock on different positions of the object to be tested, and obtain multiple knocking data, including incident signals and vibration signals;

[0010] Step 2: Process the incident signal to obtain a standard incident signal;

[0011] Step 3: Perform Fourier transform on the incident signal, vibration signal and standard incident signal after each tapping to obtain their corresponding frequency domain complex representations, and obtain the frequency domain representation of the vibration signal similar to the radar wave according to the corresponding frequency domain complex representations and the elastic wave radar algorithm theoretical formula;

[0012] Step 4: Perform an inverse Fourier transform on the frequency domain representation of the radar wave-like vibration signal to obtain the time domain waveform of the processed vibration signal.

[0013] Optionally, in step 1, different positions of the object to be measured are tapped by a vibration excitation device to obtain multiple tapping data, including incident signals and vibration signals, specifically:

[0014] Different positions of the object to be measured are struck by free fall through a vibration rod, or different positions of the object to be measured are struck directly through a vibration hammer, an incident signal is collected through a first sensor, and a vibration signal is collected through a second sensor, wherein the position struck by the vibration device is close to the second sensor, and the distance does not exceed one quarter of the thickness of the object to be measured.

[0015] Optionally, in step 2, the incident signal is processed to obtain a standard incident signal, specifically:

[0016] The standard incident signal includes the first excitation standard wave, the average standard wave, the maximum and minimum interception standard wave and the minimum and maximum interception standard wave. The incident signal waveform of the first knock is collected, and the starting point and the ending point of the incident signal waveform of the first knock are used as the starting point and the initial point of the standard sinusoidal half-wave with an amplitude of 1 to obtain the first excitation standard wave; the incident signal waveforms of all knocks are collected, and the average value of the starting point and the average value of the ending point of the incident signal waveforms of all knocks are used as the starting point and the ending point of the standard sinusoidal half-wave with an amplitude of 1 to obtain the average standard wave; the maximum value of the starting point and the minimum value of the ending point of the incident signal waveforms of all knocks are used as the starting point and the ending point of the standard sinusoidal half-wave with an amplitude of 1 to obtain the maximum and minimum interception standard wave; the minimum value of the starting point and the maximum value of the ending point of the incident signal waveforms of all knocks are used as the starting point and the ending point of the standard sinusoidal half-wave with an amplitude of 1 to obtain the minimum and maximum interception standard wave.

[0017] Optionally, in step 3, the incident signal, vibration signal and standard incident signal after each tapping are Fourier transformed to obtain their respective corresponding frequency domain complex representations, and the frequency domain representation of the vibration signal similar to the radar wave is obtained according to the respective corresponding frequency domain complex representations and the elastic wave radar algorithm theoretical formula, which is specifically:

[0018] The incident signal, vibration signal and standard incident signal after each tapping are Fourier transformed to obtain their corresponding frequency domain complex representations, which are: X i (f) Y i (f) and X0(f), X i (f) Y i Substituting X0(f) and X0(f) into the theoretical formula of elastic wave radar algorithm, the frequency domain representation of the vibration signal similar to radar wave is obtained as follows:

[0019]

[0020] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects: the elastic wave radar detection device and method provided by the present invention are provided with a first sensor and a second sensor, which can respectively collect incident signals and vibration signals, wherein the excitation device of the device is provided with two types, and an exciting hammer or an exciting rod can be selected for detection according to needs; the method comprises tapping different positions of the object to be measured by the excitation device to obtain multiple tapping data, including incident signals and vibration signals, processing the incident signal to obtain a standard incident signal, and Fourier transforming the incident signal, vibration signal and standard incident signal after each tapping to obtain The corresponding frequency domain complex number representations are used to obtain the frequency domain representation of the vibration signal similar to the radar wave according to the corresponding frequency domain complex number representations and the theoretical formula of the elastic wave radar algorithm. The frequency domain representation of the vibration signal similar to the radar wave is subjected to inverse Fourier transform to obtain the time domain waveform of the processed vibration signal. The vibration signals of knocking at different positions are processed into time domain waveforms similar to radar waves. In addition, the standard incident signal is introduced to solve the problem of inconsistent amplitude and starting point of the vibration signal and improve the uniformity. In specific use, it is only necessary to arrange them on the same interface according to the knocking order to intuitively analyze the characteristics of the object under test and improve the detection accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0022] Figure 1 This is a schematic diagram of the structure of the elastic wave radar detection device in use according to an embodiment of the present invention;

[0023] Figure 2 It is a schematic diagram of the exciting hammer structure;

[0024] Figure 3 Schematic diagram of the exciting rod structure;

[0025] Figure 4 is a schematic diagram of the rod structure;

[0026] Figure 5 is a schematic diagram of the connecting piece structure;

[0027] Figure 6 It is a schematic diagram of the hammer head structure;

[0028] Figure 7 It is the waveform diagram of the incident signal wave of the first strike;

[0029] Figure 8 This is the waveform diagram of the first excitation standard wave;

[0030] Fig. 9 It is the waveform diagram of the average standard wave;

[0031] Fig.10 The waveform diagram of the standard wave is intercepted for the maximum and minimum values;

[0032] Fig.11 The waveform diagram of the standard wave is intercepted for the minimum and maximum values;

[0033] Fig.12 It is the vibration waveform diagram;

[0034] Fig.13 This is the waveform diagram after the standard incident signal is processed with the starting point of 100;

[0035] Fig.14 This is the waveform diagram after the standard incident signal with the starting point of 400 is processed;

[0036] Fig.15 This is the time domain waveform after the average standard wave is introduced;

[0037] Fig.16 This is the radar grayscale image after the average standard wave processing is introduced;

[0038] Fig.17 This is the color contour map after the average standard wave processing is introduced.

[0039] Figure numerals: 1. measured object; 2. second sensor; 3. arc-shaped hammer head; 4. first sensor; 5. handle; 6. rod body; 7. connecting piece; 8. hammer head; 9. second thread; 10. first thread; 11. first screw hole; 12. second screw hole; 13. arc surface. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] The purpose of the present invention is to provide an elastic wave radar detection device and method, which can receive excitation information, introduce a standard incident signal, achieve signal uniformity, and improve detection accuracy.

[0042] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0043] like Figure 1-6 As shown, the elastic wave radar detection device provided by the embodiment of the present invention includes: an excitation device, a first sensor 4, a second sensor 2 and a controller, the first sensor 4 is arranged on the excitation device, the second sensor 2 is arranged on the object to be measured 1, the first sensor 4 is used to collect excitation information, that is, the incident signal, the second sensor 2 is used to collect information of the object to be measured 1, that is, the vibration signal, the first sensor 4 and the second sensor 2 are both connected to the controller, the system response spectrum is obtained through the vibration signal and the incident signal, the standard incident signal is introduced, and finally a vibration signal similar to a radar wave is obtained.

[0044] The vibration device can be manually struck by a vibration hammer or can be struck by a free fall by a vibration rod;

[0045] like Figure 2 As shown, the exciting hammer includes a handle 5 and an arc-shaped hammer head 3, the handle 5 is fixedly connected to the arc-shaped hammer head 3, the first sensor 4 is fixedly arranged on the arc-shaped hammer head 3, and the direction of the first sensor 4 is perpendicular to the arc surface of the arc-shaped hammer head 3 contacting the ground, wherein the arc-shaped hammer head 3 may be provided with a screw groove corresponding to the first sensor 4, the first sensor 4 is provided with a thread corresponding to the screw groove, and the first sensor 4 is fixedly arranged on the arc-shaped hammer head 3 through the thread and the screw groove, and accordingly, the handle 5 and the arc-shaped hammer head 3 may also be fixed by a threaded connection, or by direct welding;

[0046] like Figure 3-6 As shown, the excitation rod includes a rod body 6, a connecting member 7 and a hammer head 8, one end of the rod body 6 is provided with a first thread 10, one end of the connecting member 7 is provided with a first screw hole 11 corresponding to the first thread 10, the connecting member 7 is fixedly set on the rod body 6 through the first thread 10 and the first screw hole 11, the other end of the connecting member 7 is provided with a second screw hole 12, one end of the hammer head 8 is provided with a second thread 9 corresponding to the second screw hole 12, the hammer head 8 is fixedly set on the connecting member 7 through the second thread 9 and the second screw hole 12, the other end of the hammer head 8 is provided with an arc surface 13 for contacting the object to be measured 1, the first sensor 4 is fixedly set inside the rod body 6 or the connecting member 7, and the direction of the first sensor is consistent with the direction of the axis of the rod body.

[0047] The first sensor 4 and the second sensor 2 are both vibration sensors.

[0048] The device can also be set up with an oscilloscope or PC to view various waveforms.

[0049] The present invention also provides an elastic wave radar detection method, which is applied to the elastic wave radar detection device, and comprises the following steps:

[0050] Step 1: Use a vibration device to knock on different positions of the object to be tested, and obtain multiple knocking data, including incident signals and vibration signals;

[0051] Step 2: Process the incident signal to obtain a standard incident signal;

[0052] Step 3: Perform Fourier transform on the incident signal, vibration signal and standard incident signal after each tapping to obtain their corresponding frequency domain complex representations, and obtain the frequency domain representation of the vibration signal similar to the radar wave according to the corresponding frequency domain complex representations and the elastic wave radar algorithm theoretical formula;

[0053] Step 4: Perform inverse Fourier transform on the frequency domain representation of the radar wave-like vibration signal to obtain the time domain waveform of the processed vibration signal. The radar wave-like vibration signals are arranged in the same interface according to the order of tapping for easy viewing. Radar grayscale images and color contour maps can also be used for viewing.

[0054] In step 1, the vibration device is used to knock on different positions of the object to be tested, and multiple knocking data are obtained, including incident signals and vibration signals, specifically:

[0055] Different positions of the object to be measured are struck by free fall through a vibration rod, or different positions of the object to be measured are struck directly through a vibration hammer, incident signals are collected through a first sensor, vibration signals are collected through a second sensor, and data from multiple strikes are stored in the same data file, wherein the position struck by the vibration device is close to the second sensor, and the distance does not exceed one quarter of the thickness of the object to be measured.

[0056] In step 2, the incident signal is processed to obtain a standard incident signal, specifically:

[0057] The standard incident signal includes the first excitation standard wave, the average standard wave, the maximum and minimum intercepted standard wave and the minimum and maximum intercepted standard wave. The incident signal waveform of the first knock is collected, and the starting point and the ending point of the incident signal waveform of the first knock are used as the starting point and the initial point of the standard sinusoidal half-wave with an amplitude of 1 to obtain the first excitation standard wave; the incident signal waveforms of all knocks are collected, and the average value of the starting point and the average value of the ending point of the incident signal waveforms of all knocks are used as the starting point and the ending point of the standard sinusoidal half-wave with an amplitude of 1 to obtain the average standard wave; the maximum value of the starting point and the minimum value of the ending point of the incident signal waveforms of all knocks are used as the starting point and the ending point of the standard sinusoidal half-wave with an amplitude of 1 to obtain the maximum and minimum intercepted standard wave; the minimum value of the starting point and the maximum value of the ending point of the incident signal waveforms of all knocks are used as the starting point and the ending point of the standard sinusoidal half-wave with an amplitude of 1 to obtain the minimum and maximum intercepted standard wave;

[0058] Among them, the incident signal waveform of the first knock, the incident signal waveform of the first knock, the average standard wave, the maximum and minimum intercepted standard wave, and the minimum and maximum intercepted standard wave obtained by an embodiment of the present invention are as follows: Figure 7-11 As shown;

[0059] The standard incident signal also includes a sine half wave with any starting point, any half wave width and any amplitude.

[0060] In step 3, the incident signal, vibration signal and standard incident signal after each tapping are Fourier transformed to obtain their corresponding frequency domain complex representations. According to their corresponding frequency domain complex representations and elastic wave radar algorithm theoretical formulas, the frequency domain representation of the vibration signal similar to the radar wave is obtained, which is specifically:

[0061] The incident signal, vibration signal and standard incident signal after each tapping are Fourier transformed to obtain their corresponding frequency domain complex representations, which are: X i (f) Y i (f) and X0(f), X i (f) Y iSubstituting X0(f) and X0(f) into the theoretical formula of elastic wave radar algorithm, the frequency domain representation of the vibration signal similar to radar wave is obtained as follows:

[0062]

[0063] Performing an inverse Fourier transform on the frequency domain representation of the vibration signal similar to the radar wave to obtain the time domain waveform of the processed vibration signal;

[0064] like Fig.12 As shown, the starting points and amplitudes of the vibration signal waves are not uniform. After being processed by the introduced standard incident signal, the starting points are highly consistent. As the starting point of the standard incident signal changes, the waveform amplitude becomes uniform.

[0065] By introducing a sine half wave with any starting point, any half-wave width and any amplitude, we can conclude that the starting point of the vibration signal is consistent with the starting point of the standard incident signal. As the starting point of the standard incident signal changes, the waveform amplitude is uniform, such as Fig.13 and 14 As shown;

[0066] like Fig.15 As shown, if the purpose is to ensure the uniformity of the starting point of the vibration signal, a sinusoidal half-wave with an arbitrary starting point can be directly introduced. During on-site testing, different positions of a measuring line can be tapped in sequence from one direction to another, and the vibration signal generated by each tap on the measuring line is subjected to the above calculation processing. After processing, all the tapping vibration signals are arranged on the same interface according to the tapping order, thus forming a time domain waveform diagram.

[0067] like Fig.16 As shown, the vibration signals arranged on the same interface are plotted on the same interface, with the amplitudes represented by black, white and gray colors, to form a radar grayscale image.

[0068] like Fig.17 As shown, the amplitude is represented by color and plotted on the same interface to form a color contour map;

[0069] By using analysis methods such as time domain waveform diagram, radar grayscale diagram, color contour diagram, etc., the characteristics of the object being measured can be intuitively analyzed, such as voids, lack of thickness, and looseness.

[0070] The elastic wave radar detection device and method provided by the present invention are provided with a first sensor and a second sensor, which can respectively collect an incident signal and a vibration signal, wherein the device is provided with two types of excitation devices, and an exciting hammer or an exciting rod can be selected for detection according to needs; the method comprises knocking different positions of the object to be measured by the excitation device to obtain multiple knocking data, including an incident signal and a vibration signal, processing the incident signal to obtain a standard incident signal, and Fourier transforming the incident signal, the vibration signal and the standard incident signal after each knocking to obtain their respective corresponding frequency domain complex representations, According to the corresponding frequency domain complex number representation and elastic wave radar algorithm theoretical formula, the frequency domain representation of the vibration signal similar to the radar wave is obtained, and the frequency domain representation of the vibration signal similar to the radar wave is subjected to inverse Fourier transform to obtain the time domain waveform of the processed vibration signal. The vibration signals of knocking at different positions are processed into time domain waveforms similar to radar waves. In addition, the introduction of standard incident signals can solve the problem of inconsistent amplitude and starting point of vibration signals and improve uniformity. In specific use, it is only necessary to arrange them on the same interface according to the knocking order to intuitively analyze the characteristics of the object under test and improve the detection accuracy.

[0071] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. An elastic wave radar detection method, applied to an elastic wave radar detection device, characterized in that: The elastic wave radar detection device comprises: an excitation device, a first sensor, a second sensor and a controller, the first sensor is arranged on the excitation device, the second sensor is arranged on the measured object, the first sensor is used to collect excitation information, i.e., incident signal, the second sensor is used to collect measured object information, i.e., vibration signal, and the first sensor and the second sensor are both connected to the controller; The elastic wave radar detection method comprises the following steps: Step 1: Use a vibration device to knock on different positions of the object to be tested, and obtain multiple knocking data, including incident signals and vibration signals; Step 2: Process the incident signal to obtain a standard incident signal; Step 3: Perform Fourier transform on the incident signal, vibration signal and standard incident signal after each tapping to obtain their corresponding frequency domain complex representations, and obtain the frequency domain representation of the vibration signal similar to the radar wave according to the corresponding frequency domain complex representations and the elastic wave radar algorithm theoretical formula; Step 4: Perform inverse Fourier transform on the frequency domain representation of the vibration signal similar to the radar wave to obtain the time domain waveform of the processed vibration signal; In step 2, the incident signal is processed to obtain a standard incident signal, specifically: The standard incident signal includes the first excitation standard wave, the average standard wave, the maximum and minimum intercepted standard wave and the minimum and maximum intercepted standard wave. The incident signal waveform of the first knock is collected, and the starting point and the ending point of the incident signal waveform of the first knock are used as the starting point and the initial point of the standard sinusoidal half-wave with an amplitude of 1 to obtain the first excitation standard wave; the incident signal waveforms of all knocks are collected, and the average value of the starting point and the average value of the ending point of the incident signal waveforms of all knocks are used as the starting point and the ending point of the standard sinusoidal half-wave with an amplitude of 1 to obtain the average standard wave; the maximum value of the starting point and the minimum value of the ending point of the incident signal waveforms of all knocks are used as the starting point and the ending point of the standard sinusoidal half-wave with an amplitude of 1 to obtain the maximum and minimum intercepted standard wave; the minimum value of the starting point and the maximum value of the ending point of the incident signal waveforms of all knocks are used as the starting point and the ending point of the standard sinusoidal half-wave with an amplitude of 1 to obtain the minimum and maximum intercepted standard wave; In step 3, the incident signal, vibration signal and standard incident signal after each tapping are Fourier transformed to obtain their corresponding frequency domain complex representations. According to their corresponding frequency domain complex representations and elastic wave radar algorithm theoretical formulas, the frequency domain representation of the vibration signal similar to the radar wave is obtained, which is specifically: The incident signal, vibration signal and standard incident signal after each tapping are Fourier transformed to obtain their corresponding frequency domain complex representations, which are: X i (f) Y i (f) and X0(f), X i (f) Y i Substituting X0(f) and X0(f) into the theoretical formula of elastic wave radar algorithm, the frequency domain representation of the vibration signal similar to radar wave is obtained as follows:

2. The elastic wave radar detection method according to claim 1, characterized in that: The vibration device is an exciting hammer, which includes a handle and an arc-shaped hammer head. The handle is fixedly connected to the arc-shaped hammer head, and the first sensor is fixedly arranged on the arc-shaped hammer head. The direction of the first sensor is perpendicular to the arc surface of the arc-shaped hammer head contacting the ground.

3. The elastic wave radar detection method according to claim 1, characterized in that: The excitation device is an excitation rod, which includes a rod body, a connecting piece and a hammer head. A first thread is provided at one end of the rod body, a first screw hole is provided at one end of the connecting piece corresponding to the first thread, and the connecting piece is fixedly set on the rod body through the first thread and the first screw hole. A second screw hole is provided at the other end of the connecting piece, a second thread is provided at one end of the hammer head corresponding to the second screw hole, and the hammer head is fixedly set on the connecting piece through the second thread and the second screw hole. An arc surface is provided at the other end of the hammer head for contacting the object to be measured. The first sensor is fixedly set inside the rod body or the connecting piece, and the direction of the first sensor is consistent with the direction of the axis of the rod body.

4. The elastic wave radar detection method according to claim 1, characterized in that: In step 1, the vibration device is used to knock on different positions of the object to be tested, and multiple knocking data are obtained, including incident signals and vibration signals, specifically: Different positions of the object to be measured are struck by free fall through a vibration rod, or different positions of the object to be measured are struck directly through a vibration hammer, an incident signal is collected through a first sensor, and a vibration signal is collected through a second sensor, wherein the position struck by the vibration device is close to the second sensor, and the distance does not exceed one quarter of the thickness of the object to be measured.

Images