A terahertz non-destructive testing system and method

Abstract

The application provides a terahertz nondestructive testing system and method. The system comprises a signal acquisition device and an imaging control platform. The acquisition device comprises a scanning signal generation unit, a sample moving unit and a echo signal receiving unit. The imaging control platform comprises a parameter setting unit, a scanning mode unit, a motion control unit and a multi-level image display unit. The motion control unit controls the sample moving unit to move according to the scanning value sent by the parameter setting unit and the scanning mode sent by the scanning mode unit, so that the echo signal receiving unit receives the echo signal corresponding to the different preset positions of the sample to be tested. The topography of the sample to be tested is not limited. The echo signal can be integrated and processed by the multi-level image display unit, and can be analyzed and calculated in depth. The multi-dimensional detection information of the sample to be tested can be directly displayed, and the detection efficiency is high.

Description

Technical Field

[0001] This application relates to the field of radar imaging, and in particular to a terahertz nondestructive testing system and method. Background Technology

[0002] Composite materials, due to their lightweight, high strength, high ductility, corrosion resistance, flexible preparation, and ease of processing, are widely used in aerospace thermal insulation materials, solid rocket motor casings, and missile radomes. However, the complex molding process of composite materials means that many subtle processing uncertainties inevitably lead to defects in the material structure. Furthermore, various types of damage may occur during the use of composite materials. These defects and damage pose a significant threat to the safety of composite materials in use.

[0003] Terahertz waves, located between microwaves and infrared, offer superior resolution compared to microwave or millimeter-wave imaging due to their shorter wavelength and wider bandwidth. Furthermore, terahertz imaging is a completely non-contact method, achieving even higher resolution than ultrasonic imaging. Therefore, terahertz imaging has become a novel and important supplementary tool for non-destructive testing. In addition, terahertz waves have high penetrability into composite materials, enabling non-destructive testing of the internal structure of composite materials using terahertz non-destructive testing techniques.

[0004] Existing nondestructive testing imaging methods mostly use two-dimensional planar scanning, which imposes certain limitations on the morphology of the sample being tested. Furthermore, they do not integrate and deeply analyze the various data generated during nondestructive testing, failing to intuitively display the specific testing information of the sample, resulting in low testing efficiency. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a terahertz nondestructive testing system and method, the specific solution of which is as follows:

[0006] In a first aspect, embodiments of this application provide a terahertz nondestructive testing system, the terahertz nondestructive testing system including a signal acquisition device and an imaging control platform, the acquisition device including a scanning signal generation unit, a sample movement unit and an echo signal receiving unit, the imaging control platform including a parameter setting unit, a scanning mode unit, a motion control unit and a multi-level image display unit;

[0007] The scanning signal generating unit is used to generate a scanning signal so that the scanning signal is propagated to the sample to be tested on the sample moving unit and reflects the echo signal to the echo signal receiving unit.

[0008] The parameter setting unit is used to set the scanning values ​​corresponding to the first type of scanning parameters, wherein the first type of scanning parameters includes the coverage area of ​​the scanning signal, the scanning interval, and the scanning speed;

[0009] The scanning mode unit is used to set the second type of scanning mode corresponding to the sample to be tested, wherein the second type of scanning mode includes planar scanning, cylindrical scanning and continuous acquisition scanning;

[0010] The motion control unit is used to control the sample moving unit to move according to the scan value sent by the parameter setting unit and the scan mode sent by the scan mode unit, so that the echo signal receiving unit receives echo signals corresponding to different preset positions of the sample to be tested.

[0011] The multi-level image display unit is used to generate and display multi-level image information corresponding to the sample under test based on the echo signals transmitted by the echo signal receiving unit. The multi-level image information includes one-dimensional distance image, two-dimensional image information and three-dimensional image information.

[0012] According to a specific embodiment disclosed in this application, the sample moving unit includes a two-dimensional translation stage and a turntable, wherein the two-dimensional translation stage is connected to the turntable;

[0013] The motion control unit is specifically used for:

[0014] Receive the scanning mode sent by the scanning mode unit;

[0015] If the scanning mode is planar scanning, the two-dimensional translation stage is controlled to translate so as to achieve planar scanning of the sample to be tested by the scanning signal;

[0016] If the scanning mode is cylindrical scanning, control the two-dimensional translation stage to translate and / or control the turntable to rotate, so as to realize the cylindrical scanning of the sample to be tested by the scanning signal;

[0017] If the scanning mode is continuous acquisition scanning, the two-dimensional translation stage is controlled to translate and the turntable is controlled to rotate, so as to realize the continuous scanning of the sample to be tested by the scanning signal.

[0018] According to a specific embodiment disclosed in this application, the multi-level image display unit includes a one-dimensional distance image display subunit, and the multi-level image display unit is specifically used for:

[0019] The system receives time-domain data corresponding to each echo signal transmitted by the echo signal receiving unit, wherein each echo signal corresponds to a different preset position of the sample under test.

[0020] The time-domain data are converted into voltages and subjected to a third type of preset processing to obtain frequency-domain data and a one-dimensional distance image corresponding to each preset position. The third type of preset processing includes phase compensation, filtering, and Fourier transform.

[0021] According to a specific embodiment disclosed in this application, the multi-level image display unit further includes a two-dimensional image display sub-unit, and the multi-level image display unit is specifically used for:

[0022] Select all frequency domain data corresponding to the preset positions within a preset range as target data;

[0023] Integrate the target data to obtain the intensity value corresponding to the current preset position within a preset range;

[0024] The intensity values ​​corresponding to all preset positions are fused and displayed to obtain a two-dimensional image of the sample to be tested.

[0025] According to a specific embodiment disclosed in this application, the multi-level image display unit further includes a three-dimensional image display subunit, and the multi-level image display unit is specifically used for:

[0026] The one-dimensional distance images are stitched together in three dimensions to obtain the three-dimensional matrix corresponding to the sample under test.

[0027] Receive user input regarding the 3D coordinate display range and distance image layer number;

[0028] Based on the coordinate display range and the distance image layer, the slice information corresponding to different depth distances of the sample under test is displayed.

[0029] Secondly, embodiments of this application provide a terahertz nondestructive testing method, wherein the terahertz nondestructive testing method is applied to the terahertz nondestructive testing system described in any embodiment of the first aspect, and the terahertz nondestructive testing method includes:

[0030] The scanning signal generating unit generates a scanning signal, which is then propagated to the sample to be tested on the sample moving unit and reflected back to the echo signal receiving unit.

[0031] The parameter setting unit sets the scanning values ​​corresponding to the first type of scanning parameters, wherein the first type of scanning parameters includes the coverage area of ​​the scanning signal, the scanning interval, and the scanning speed;

[0032] The scanning mode unit sets the second type of scanning mode corresponding to the sample to be tested, wherein the second type of scanning mode includes planar scanning, cylindrical scanning and continuous acquisition scanning;

[0033] The motion control unit controls the sample moving unit to move according to the scan value sent by the parameter setting unit and the scan mode sent by the scan mode unit, so that the echo signal receiving unit receives echo signals corresponding to different preset positions of the sample to be tested.

[0034] The multi-level image display unit generates and displays multi-level image information corresponding to the sample under test based on the echo signals transmitted by the echo signal receiving unit. The multi-level image information includes one-dimensional distance image, two-dimensional image information and three-dimensional image information.

[0035] According to a specific embodiment disclosed in this application, the sample moving unit includes a two-dimensional translation stage and a turntable, wherein the two-dimensional translation stage is connected to the turntable;

[0036] The motion control unit controls the sample movement unit to move according to the scan values ​​sent by the parameter setting unit and the scan mode sent by the scan mode unit, including the following steps:

[0037] Receive the scanning mode sent by the scanning mode unit;

[0038] If the scanning mode is planar scanning, the two-dimensional translation stage is controlled to translate so as to achieve planar scanning of the sample to be tested by the scanning signal;

[0039] If the scanning mode is cylindrical scanning, control the two-dimensional translation stage to translate and / or control the turntable to rotate, so as to realize the cylindrical scanning of the sample to be tested by the scanning signal;

[0040] If the scanning mode is continuous acquisition scanning, the two-dimensional translation stage is controlled to translate and the turntable is controlled to rotate, so as to realize the continuous scanning of the sample to be tested by the scanning signal.

[0041] According to a specific embodiment disclosed in this application, the multi-level image display unit includes a one-dimensional distance image display subunit;

[0042] The step of the multi-level image display unit generating and displaying multi-level image information corresponding to the sample under test based on each echo signal transmitted by the echo signal receiving unit includes:

[0043] The system receives time-domain data corresponding to each echo signal transmitted by the echo signal receiving unit, wherein each echo signal corresponds to a different preset position of the sample under test.

[0044] The time-domain data are converted into voltages and subjected to a third type of preset processing to obtain frequency-domain data and a one-dimensional distance image corresponding to each preset position. The third type of preset processing includes phase compensation, filtering, and Fourier transform.

[0045] According to a specific embodiment disclosed in this application, the multi-level image display unit further includes a two-dimensional image display subunit;

[0046] The step of the multi-level image display unit generating and displaying multi-level image information corresponding to the sample under test based on each echo signal transmitted by the echo signal receiving unit includes:

[0047] Select all frequency domain data corresponding to the preset positions within a preset range as target data;

[0048] Integrate the target data to obtain the intensity value corresponding to the current preset position within a preset range;

[0049] The intensity values ​​corresponding to all preset positions are fused and displayed to obtain a two-dimensional image of the sample to be tested.

[0050] According to a specific embodiment disclosed in this application, the multi-level image display unit further includes a three-dimensional image display subunit;

[0051] The step of the multi-level image display unit generating and displaying multi-level image information corresponding to the sample under test based on each echo signal transmitted by the echo signal receiving unit includes:

[0052] The one-dimensional distance images are stitched together in three dimensions to obtain the three-dimensional matrix corresponding to the sample under test.

[0053] Receive user input regarding the 3D coordinate display range and distance image layer number;

[0054] Based on the coordinate display range and the distance image layer, the slice information corresponding to different depth distances of the sample under test is displayed.

[0055] Compared with the prior art, this application has the following beneficial effects:

[0056] The terahertz nondestructive testing system provided in this application includes a signal acquisition device and an imaging control platform. The acquisition device includes a scanning signal generation unit, a sample movement unit, and an echo signal receiving unit. The imaging control platform includes a parameter setting unit, a scanning mode unit, a motion control unit, and a multi-level image display unit. The motion control unit in this application controls the sample movement unit to move according to the scanning values ​​sent by the parameter setting unit and the scanning mode sent by the scanning mode unit, so that the echo signal receiving unit receives echo signals from different preset positions of the sample under test, without limitation on the morphology of the sample. Furthermore, the multi-level image display unit can integrate and process the echo signals, perform in-depth analysis and calculation, and intuitively display multi-dimensional detection information of the sample under test, resulting in high detection efficiency. Attached Figure Description

[0057] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0058] Figure 1 This is a schematic diagram of the composition of a terahertz nondestructive testing system provided in an embodiment of this application;

[0059] Figure 2 This is a flowchart illustrating a terahertz nondestructive testing method provided in an embodiment of this application. Detailed Implementation

[0060] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0061] The components of the embodiments of the invention described and illustrated herein can typically be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0062] In the following, the terms “comprising,” “having,” and their cognates, which may be used in various embodiments of the invention, are intended only to indicate a particular feature, number, step, operation, element, component, or combination thereof, and should not be construed as excluding, firstly, the presence of one or more other features, numbers, steps, operations, elements, components, or combinations thereof, or adding the possibility of one or more features, numbers, steps, operations, elements, components, or combinations thereof.

[0063] Furthermore, the terms "first," "second," and "third" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0064] Unless otherwise specified, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which the various embodiments of the invention pertain. Terms (such as those defined in commonly used dictionaries) shall be interpreted as having the same meaning as in their contextual meaning in the relevant technical field and shall not be interpreted as having an idealized or overly formal meaning, unless clearly defined in the various embodiments of the invention.

[0065] The following detailed description of some embodiments of this application is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0066] See Figure 1 , Figure 1 This is a schematic diagram of the composition of a terahertz nondestructive testing system provided in an embodiment of this application.

[0067] The terahertz nondestructive testing system includes a signal acquisition device 11 and an imaging control platform 12. The signal acquisition device 11 includes a scanning signal generation unit 111, a sample movement unit 112, and an echo signal receiving unit 113. The imaging control platform 12 includes a parameter setting unit 121, a scanning mode unit 122, a motion control unit 123, and a multi-level image display unit 124.

[0068] The scanning signal generating unit 111 is used to generate a scanning signal so that the scanning signal is transmitted to the sample to be tested on the sample moving unit 112 and the echo signal is reflected to the echo signal receiving unit 113.

[0069] The parameter setting unit 121 is used to set the scanning value corresponding to the first type of scanning parameters, wherein the first type of scanning parameters includes the coverage range of the scanning signal, the scanning interval, and the scanning speed.

[0070] The scanning mode unit 122 is used to set the second type of scanning mode corresponding to the sample to be tested, wherein the second type of scanning mode includes planar scanning, cylindrical scanning and continuous acquisition scanning.

[0071] The motion control unit 123 is used to control the sample moving unit 112 to move according to the scanning value sent by the parameter setting unit 121 and the scanning mode sent by the scanning mode unit 122, so that the echo signal receiving unit 113 receives echo signals corresponding to different preset positions of the sample to be tested.

[0072] It should be noted that, in practice, the scanning speed adjustment can be achieved in different ways:

[0073] 1. The position of the sample to be tested remains unchanged, that is, the real-time position of the sample moving unit 112 carrying the sample to be tested does not change, only the position of the scanning signal generating unit 111 is adjusted. The adjustment method includes, but is not limited to, moving the position of the scanning signal generating unit 111 up and down or rotating the signal generating end of the scanning signal generating unit 111 along its fixed end, that is, adjusting the angle of the scanning signal unit;

[0074] 2. The sample moving unit 112 may include a two-dimensional translation stage and a turntable, wherein the two-dimensional translation stage is connected to the turntable. In this case, the position or angle of the scanning signal generating unit 111 may also be kept unchanged, and the sample to be tested may be moved or rotated by controlling the translation speed of the two-dimensional translation stage and / or the rotational angular velocity of the turntable, thereby achieving the effect of adjusting the scanning speed.

[0075] For similar reasons, the adjustment of the scanning mode can also be achieved by the motion control unit 123 controlling the two-dimensional translation stage and / or the turntable. Specifically, the motion control unit 123 receives the scanning mode sent by the scanning mode unit 122, then determines the second type corresponding to the scanning mode, and determines the specific movement mode of the sample movement unit 112 according to the different second type of scanning mode:

[0076] If the scanning mode is planar scanning, the two-dimensional translation stage is controlled to translate so as to achieve planar scanning of the sample to be tested by the scanning signal;

[0077] If the scanning mode is cylindrical scanning, control the two-dimensional translation stage to translate and / or control the turntable to rotate, so as to realize the cylindrical scanning of the sample to be tested by the scanning signal;

[0078] If the scanning mode is continuous acquisition scanning, the two-dimensional translation stage is controlled to translate and the turntable is controlled to rotate, so as to realize the continuous scanning of the sample to be tested by the scanning signal.

[0079] The multi-level image display unit 124 is used to generate and display multi-level image information corresponding to the sample under test based on the echo signals transmitted by the echo signal receiving unit 113. The multi-level image information includes one-dimensional distance image, two-dimensional image information and three-dimensional image information.

[0080] Specifically, the multi-level image display unit 124 includes, but is not limited to, a one-dimensional distance image display subunit 1241, a two-dimensional image display subunit 1242, and a three-dimensional image display subunit 1243.

[0081] The one-dimensional distance image display subunit 1241 filters, calibrates nonlinearity, and performs Fourier transform on the time-domain information returned by the scanning signal after propagating to a preset position on the sample under test during the detection process, obtaining frequency-domain data and one-dimensional distance images corresponding to each preset position. The one-dimensional distance image is the projection of all echo signals (i.e., vector sum) of the two-dimensional image corresponding to the sample under test along its radial direction. The internal structural information of the sample under test can be analyzed in real time using the one-dimensional distance images at each preset position.

[0082] The two-dimensional image display subunit 1242 utilizes the intensity value obtained by integrating the frequency domain data in the one-dimensional distance image display subunit 1241. By fusing and displaying the intensity values ​​corresponding to all preset positions, a two-dimensional image corresponding to the sample under test can be obtained.

[0083] The three-dimensional image display subunit 1243 stitches together the one-dimensional distance images corresponding to the preset positions and further processes them into a three-dimensional image, and then displays the three-dimensional image in a slice-style manner.

[0084] One or more of these sub-units can be selected for image display based on the user's actual needs and specific application scenarios. The working principles or processes of each of these sub-units are explained below:

[0085] 1. The one-dimensional distance image display subunit 1241 is specifically used for:

[0086] The time-domain data corresponding to each echo signal transmitted by the echo signal receiving unit 113 are received, wherein each echo signal corresponds to a different preset position of the sample to be tested.

[0087] The time-domain data are converted into voltages and subjected to a third type of preset processing to obtain frequency-domain data and a one-dimensional distance image corresponding to each preset position. The third type of preset processing includes phase compensation, filtering, and Fourier transform.

[0088] The one-dimensional range image display subunit 1241 can acquire the time-domain signal corresponding to the current scanning position (i.e., the preset position) through a data acquisition card and convert the time-domain signal into a voltage value. Since radio frequency (RF) devices such as the scanning signal generation unit 111 in the acquisition device introduce group delay into the broadband signal, severely degrading signal quality, a nonlinear calibration algorithm is needed to perform phase compensation on the intermediate frequency (IF) signal after passing through the RF devices, thereby eliminating the influence of the broadband RF devices. Therefore, the converted voltage value needs to undergo nonlinear calibration again. After filtering and applying a Hanning window to the calibrated IF signal, a Fourier transform is performed to obtain the one-dimensional range image corresponding to each preset position. The Hanning window can significantly reduce the influence of sidelobes.

[0089] 2. The two-dimensional image display subunit 1242 is specifically used for:

[0090] Select all frequency domain data corresponding to the preset positions within a preset range as target data;

[0091] Integrate the target data to obtain the intensity value corresponding to the current preset position within a preset range;

[0092] The intensity values ​​corresponding to all preset positions are fused and displayed to obtain a two-dimensional image of the sample to be tested.

[0093] The two-dimensional image display subunit 1242 uses the integral value of the interval before and after each preset position, i.e., within a preset range, as the intensity value of the preset position. Therefore, based on the intensity difference at different scanning positions, i.e., preset positions, the defect type, size, and corresponding defect location of the sample under test can be determined. The specific size of the preset range can be customized according to the user's needs and specific application scenarios, and is not further limited here.

[0094] 3. The three-dimensional image display subunit 1243 is specifically used for:

[0095] The one-dimensional distance images are stitched together in three dimensions to obtain the three-dimensional matrix corresponding to the sample under test.

[0096] Receive user input regarding the 3D coordinate display range and distance image layer number;

[0097] Based on the coordinate display range and the distance image layer, the slice information corresponding to different depth distances of the sample under test is displayed.

[0098] The 3D image display subunit 1243 stitches the one-dimensional distance image processed by the 1D distance image display subunit 1241 into a 3D matrix of the sample under test. Furthermore, the coordinate display range and the number of distance image layers can be set to view slice information at different distances, allowing for more accurate determination of the type and location of defects such as delamination, separation, and voids within the distance image layers. Figure 1 The 3D image display subunit 1243 shown can set the coordinate display range, i.e., the values ​​of x and y, and the number of distance image layers on its display interface. The number of distance image layers refers to the number of layers into which the 3D image corresponding to the sample under test is divided along the z-axis. For example, if the number of distance image layers is 3, then 3 slices of information corresponding to the sample under test can be obtained.

[0099] In specific implementation, the terahertz nondestructive testing system may also include a file storage unit, which is used to save the acquired intermediate frequency raw data in the form of a BIN file in a specified path, and at the same time save the processed three-dimensional matrix in MAT format, so as to facilitate subsequent data processing and playback.

[0100] The motion control unit in this application controls the sample movement unit to move according to the scan values ​​sent by the parameter setting unit and the scan mode sent by the scan mode unit, so that the echo signal receiving unit receives echo signals from different preset positions of the sample under test, without limitation on the morphology of the sample under test. Furthermore, the multi-level image display unit can integrate and process the echo signals, and perform in-depth analysis and calculation, intuitively displaying multi-dimensional detection information of the sample under test, resulting in high detection efficiency.

[0101] Corresponding to the above system embodiments, see [link to relevant documentation]. Figure 2 , Figure 2 This is a flowchart illustrating a terahertz nondestructive testing method provided in an embodiment of this application. The terahertz nondestructive testing method includes:

[0102] In step S201, the scanning signal generating unit generates a scanning signal so that the scanning signal is propagated to the sample to be tested on the sample moving unit and the echo signal is reflected to the echo signal receiving unit.

[0103] Step S202: The parameter setting unit sets the scanning value corresponding to the first type of scanning parameters, wherein the first type of scanning parameters includes the coverage area of ​​the scanning signal, the scanning interval, and the scanning speed.

[0104] Step S203: The scanning mode unit sets the second type of scanning mode corresponding to the sample to be tested, wherein the second type of scanning mode includes planar scanning, cylindrical scanning and continuous acquisition scanning.

[0105] In step S204, the motion control unit controls the sample moving unit to move according to the scanning value sent by the parameter setting unit and the scanning mode sent by the scanning mode unit, so that the echo signal receiving unit receives echo signals corresponding to different preset positions of the sample to be tested.

[0106] In a specific implementation, the sample moving unit includes a two-dimensional translation stage and a turntable, and the two-dimensional translation stage is connected to the turntable;

[0107] The motion control unit controls the sample movement unit to move according to the scan values ​​sent by the parameter setting unit and the scan mode sent by the scan mode unit, including the following steps:

[0108] Receive the scanning mode sent by the scanning mode unit;

[0109] If the scanning mode is planar scanning, the two-dimensional translation stage is controlled to translate so as to achieve planar scanning of the sample to be tested by the scanning signal;

[0110] If the scanning mode is cylindrical scanning, control the two-dimensional translation stage to translate and / or control the turntable to rotate, so as to realize the cylindrical scanning of the sample to be tested by the scanning signal;

[0111] If the scanning mode is continuous acquisition scanning, the two-dimensional translation stage is controlled to translate and the turntable is controlled to rotate, so as to realize the continuous scanning of the sample to be tested by the scanning signal.

[0112] In step S205, the multi-level image display unit generates and displays multi-level image information corresponding to the sample under test based on the echo signals transmitted by the echo signal receiving unit. The multi-level image information includes one-dimensional distance image, two-dimensional image information, and three-dimensional image information.

[0113] In a specific implementation, the multi-level image display unit includes a one-dimensional distance image display subunit;

[0114] The step of the multi-level image display unit generating and displaying multi-level image information corresponding to the sample under test based on each echo signal transmitted by the echo signal receiving unit includes:

[0115] The system receives time-domain data corresponding to each echo signal transmitted by the echo signal receiving unit, wherein each echo signal corresponds to a different preset position of the sample under test.

[0116] The time-domain data are converted into voltages and subjected to a third type of preset processing to obtain frequency-domain data and a one-dimensional distance image corresponding to each preset position. The third type of preset processing includes phase compensation, filtering, and Fourier transform.

[0117] In a specific implementation, the multi-level image display unit further includes a two-dimensional image display subunit;

[0118] The step of the multi-level image display unit generating and displaying multi-level image information corresponding to the sample under test based on each echo signal transmitted by the echo signal receiving unit includes:

[0119] Select all frequency domain data corresponding to the preset positions within a preset range as target data;

[0120] Integrate the target data to obtain the intensity value corresponding to the current preset position within a preset range;

[0121] The intensity values ​​corresponding to all preset positions are fused and displayed to obtain a two-dimensional image of the sample to be tested.

[0122] In a specific implementation, the multi-level image display unit further includes a three-dimensional image display subunit;

[0123] The step of the multi-level image display unit generating and displaying multi-level image information corresponding to the sample under test based on each echo signal transmitted by the echo signal receiving unit includes:

[0124] The one-dimensional distance images are stitched together in three dimensions to obtain the three-dimensional matrix corresponding to the sample under test.

[0125] Receive user input regarding the 3D coordinate display range and distance image layer number;

[0126] Based on the coordinate display range and the distance image layer, the slice information corresponding to different depth distances of the sample under test is displayed.

[0127] The specific implementation process of the terahertz nondestructive testing method provided in this application can be found in the specific implementation process of the terahertz nondestructive testing system provided in the above embodiments, and will not be repeated here.

[0128] The terahertz nondestructive testing method provided in this application uses a motion control unit to control a sample movement unit based on the scan values ​​sent by the parameter setting unit and the scan mode sent by the scan mode unit. This allows the echo signal receiving unit to receive echo signals from different preset positions of the sample under test, without limitation on the morphology of the sample. Furthermore, a multi-level image display unit can integrate and process the echo signals, performing in-depth analysis and calculations. This provides a clear and intuitive display of multi-dimensional detection information of the sample under test, resulting in high detection efficiency.

[0129] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can also be implemented in other ways. The apparatus embodiments described above are merely illustrative; for example, the flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of apparatus, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that, as an alternative implementation, the functions marked in the blocks may occur in a different order than those marked in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagram and / or flowchart, and combinations of blocks in the block diagram and / or flowchart, can be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

[0130] In addition, the functional modules or units in the various embodiments of the present invention can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.

[0131] If the aforementioned functions are implemented as software functional modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a smartphone, personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0132] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A terahertz non-destructive testing system, characterized by, The terahertz nondestructive detection system comprises a signal acquisition device and an imaging control platform, the acquisition device comprises a scanning signal generation unit, a sample moving unit and a echo signal receiving unit, and the imaging control platform comprises a parameter setting unit, a scanning mode unit, a motion control unit and a multi-level image display unit; The scanning signal generation unit is configured to generate a scanning signal, so that the scanning signal propagates to a sample to be tested on the sample moving unit and reflects an echo signal to the echo signal receiving unit; The parameter setting unit is configured to set a scanning value corresponding to a first type of scanning parameter, wherein the first type of scanning parameter comprises a coverage range of the scanning signal, a scanning interval and a scanning speed; The scanning mode unit is configured to set a second type of scanning mode corresponding to the sample to be tested, wherein the second type of scanning mode comprises plane scanning, cylindrical scanning and continuous acquisition scanning; The motion control unit is configured to control the sample moving unit to move according to the scanning value sent by the parameter setting unit and the scanning mode sent by the scanning mode unit, so that the echo signal receiving unit receives echo signals corresponding to different preset positions of the sample to be tested; The multi-level image display unit is configured to generate and display multi-level image information corresponding to the sample to be tested according to each echo signal transmitted by the echo signal receiving unit, wherein the multi-level image information comprises one-dimensional range image, two-dimensional image information and three-dimensional image information; The internal structure information of the sample to be tested is analyzed in real time through the one-dimensional range image of each preset position; The multi-level image display unit comprises a one-dimensional range image display subunit, and the multi-level image display unit is specifically configured to: Receive time domain data corresponding to each echo signal transmitted by the echo signal receiving unit, wherein each echo signal corresponds to a different preset position of the sample to be tested; Convert each time domain data into voltage and perform a third type of preset processing to obtain frequency domain data corresponding to each preset position and one-dimensional range image, wherein the third type of preset processing comprises phase compensation, filtering and Fourier transform.

2. The terahertz non-destructive testing system of claim 1, wherein, The sample moving unit comprises a two-dimensional translation stage and a rotary table, and the two-dimensional translation stage is connected with the rotary table; The motion control unit is specifically configured to: Receive the scanning mode sent by the scanning mode unit; If the scanning mode is plane scanning, control the two-dimensional translation stage to translate to realize plane scanning of the sample to be tested by the scanning signal; If the scanning mode is cylindrical scanning, control the two-dimensional translation stage to translate and / or control the rotary table to rotate to realize cylindrical scanning of the sample to be tested by the scanning signal; If the scanning mode is continuous acquisition scanning, control the two-dimensional translation stage to translate and control the rotary table to rotate to realize continuous scanning of the sample to be tested by the scanning signal.

3. The terahertz non-destructive testing system of claim 2, wherein, The multi-level image display unit further comprises a two-dimensional image display subunit, and the multi-level image display unit is specifically configured to: Select all frequency domain data corresponding to the preset positions in a preset range of each preset position as target data; Integrate the target data to obtain an intensity value corresponding to the preset position in a preset range; Fuse and display the intensity values corresponding to all preset positions to obtain a two-dimensional image corresponding to the sample to be measured.

4. The terahertz non-destructive testing system of claim 2, wherein, The multi-level image display unit further comprises a three-dimensional image display subunit, and the multi-level image display unit is specifically used for: The one-dimensional range images are spliced into a three-dimensional matrix corresponding to the sample to be measured; Receiving a three-dimensional coordinate display range and a range image layer number input by a user; According to the coordinate display range and the range image layer number, slice information corresponding to different depth ranges of the sample to be measured is displayed.

5. A terahertz non-destructive testing method, characterized by, The terahertz nondestructive detection system of any one of claims 1-4, the terahertz nondestructive detection method comprising: The scanning signal generation unit generates a scanning signal, so that the scanning signal propagates to the sample to be measured on the sample moving unit and reflects a return signal to the return signal receiving unit; The parameter setting unit sets a scanning value corresponding to a first type of scanning parameter, wherein the first type of scanning parameter includes a coverage range, a scanning interval, and a scanning speed of the scanning signal; The scanning mode unit sets a second type of scanning mode corresponding to the sample to be measured, wherein the second type of scanning mode includes plane scanning, cylindrical scanning, and continuous acquisition scanning; The motion control unit controls the sample moving unit to move according to the scanning value sent by the parameter setting unit and the scanning mode sent by the scanning mode unit, so that the return signal receiving unit receives return signals corresponding to different preset positions of the sample to be measured; The multi-level image display unit generates and displays multi-level image information corresponding to the sample to be measured according to each return signal transmitted by the return signal receiving unit, wherein the multi-level image information includes one-dimensional range images, two-dimensional image information, and three-dimensional image information.

6. The terahertz non-destructive testing method according to claim 5, characterized in that, The sample moving unit comprises a two-dimensional translation stage and a rotary table, and the two-dimensional translation stage is connected to the rotary table; The motion control unit controls the sample moving unit to move according to the scanning value sent by the parameter setting unit and the scanning mode sent by the scanning mode unit, including: Receiving the scanning mode sent by the scanning mode unit; If the scanning mode is plane scanning, the two-dimensional translation stage is controlled to translate to realize plane scanning of the sample to be measured by the scanning signal; If the scanning mode is cylindrical scanning, the two-dimensional translation stage is controlled to translate and / or the rotary table is controlled to rotate to realize cylindrical scanning of the sample to be measured by the scanning signal; If the scanning mode is continuous acquisition scanning, the two-dimensional translation stage is controlled to translate and the rotary table is controlled to rotate to realize continuous scanning of the sample to be measured by the scanning signal.

7. The terahertz non-destructive testing method of claim 5, wherein, The multi-level image display unit comprises a one-dimensional range image display subunit; The multi-level image display unit generates and displays multi-level image information corresponding to the sample to be measured according to each return signal transmitted by the return signal receiving unit, including: Receiving time domain data corresponding to each echo signal transmitted by the echo signal receiving unit, wherein each echo signal corresponds to a different preset position of the sample to be measured; Converting each time domain data into voltage and performing a third type of preset processing to obtain frequency domain data corresponding to each preset position and one-dimensional range image, wherein the third type of preset processing includes phase compensation, filtering and Fourier transform.

8. The terahertz non-destructive testing method of claim 7, wherein, The multi-level image display unit further comprises a two-dimensional image display subunit; The step of generating and displaying multi-level image information corresponding to the sample to be measured by the multi-level image display unit according to each echo signal transmitted by the echo signal receiving unit comprises: Selecting frequency domain data corresponding to all preset positions in a preset range of each preset position as target data; Integrating the target data to obtain an intensity value corresponding to the current preset position in the preset range; Fusing and displaying intensity values corresponding to all preset positions to obtain a two-dimensional image corresponding to the sample to be measured.

9. The terahertz non-destructive testing method of claim 7, wherein, The multi-level image display unit further comprises a three-dimensional image display subunit; The step of generating and displaying multi-level image information corresponding to the sample to be measured by the multi-level image display unit according to each echo signal transmitted by the echo signal receiving unit comprises: Three-dimensionally splicing each one-dimensional range image to obtain a three-dimensional matrix corresponding to the sample to be measured; Receiving a three-dimensional coordinate display range and a range image layer number input by a user; Displaying slice information corresponding to different depth distances of the sample to be measured according to the coordinate display range and the range image layer number.

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