Terahertz-based nonmetal pipeline defect detection method, system and equipment

Abstract

The invention relates to the field of nondestructive testing, and discloses a terahertz-based nonmetal pipeline defect detection method, system and equipment, and the detection method comprises the following steps: obtaining a first terahertz detection signal of a to-be-detected nonmetal pipeline; obtaining a first terahertz detection waveform based on the first terahertz detection signal; a corresponding relation between defect types and terahertz detection waveforms is obtained from a preset database, each defect type corresponds to three types of detection waveforms, and a target defect type corresponding to the defect in the pipeline is determined based on the first terahertz detection waveform and the corresponding relation; determining three-dimensional size data of the defect based on the target defect type and the first terahertz detection signal; and constructing a target three-dimensional structure of the defect based on the first terahertz detection signal and the three-dimensional size data. Therefore, a relatively complete and mature terahertz detection method can be provided for the non-metal pipeline, so that the terahertz detection means can be conveniently popularized in the field of non-metal pipeline detection.

Description

Technical Field

[0001] The present invention relates to the technical field of non-destructive testing, and particularly to a method for detecting defects in non-metallic pipelines based on terahertz, a system for detecting defects in non-metallic pipelines based on terahertz, and a device for detecting defects in non-metallic pipelines based on terahertz. Background Art

[0002] To solve the corrosion problem of carbon steel pipes, non-metallic pipes have been widely used as conveying pipelines in fields such as petroleum, chemical industry, and urban gas. With the increasing proportion of non-metallic pipelines, the defect detection of non-metallic pipelines is crucial for ensuring safe transportation.

[0003] Due to the characteristics of good penetration, low energy, transient nature, high resolution, and non-contact of terahertz electromagnetic waves, they are suitable as a detection means for non-metallic pipelines. However, for non-metallic pipelines, there is currently no relatively perfect and mature terahertz detection method, which has hindered the popularization and development of terahertz detection means in the field of non-metallic pipeline detection. Summary of the Invention

[0004] The purpose of the present invention is to overcome the problem in the prior art that there is no perfect and mature terahertz detection method for non-metallic pipelines, and to provide a method, a system, and a device for detecting defects in non-metallic pipelines based on terahertz.

[0005] To achieve the above purpose, in the first aspect of the present invention, a method for detecting defects in non-metallic pipelines based on terahertz is provided. The detection method includes:

[0006] Obtaining a first terahertz detection signal of the non-metallic pipeline to be detected;

[0007] Based on the first terahertz detection signal, obtaining a first terahertz detection waveform of the non-metallic pipeline to be detected;

[0008] Obtaining the correspondence between defect types and terahertz detection waveforms from a preset database, and based on the first terahertz detection waveform and the correspondence, determining the target defect type corresponding to the defect in the non-metallic pipeline to be detected; wherein, in the correspondence, each defect type corresponds to three types of detection waveforms, and the three types of detection waveforms include single-point scanning detection waveforms, line scanning detection waveforms, and surface scanning detection waveforms;

[0009] Based on the target defect type and the first terahertz detection signal, determining three-dimensional dimension data of the defect in the non-metallic pipeline to be detected;

[0010] Based on the first terahertz detection signal and the three-dimensional dimension data, constructing a target three-dimensional structure of the defect in the non-metallic pipeline to be detected.

[0011] In the embodiment of the present application, the first terahertz detection signal is generated by a terahertz probe scanning the non-metallic pipeline to be detected according to a preset scanning path, and the preset scanning path includes:

[0012] Starting from the scanning starting point, performing line scanning along the axial direction of the non-metallic pipeline to be detected;

[0013] After each line scanning is completed, stepping a preset distance along the circumferential direction of the non-metallic pipeline to be detected, and then performing line scanning along the axial direction of the non-metallic pipeline to be detected again.

[0014] In the embodiment of the present application, constructing the target three-dimensional structure of the defect in the non-metallic pipeline to be detected based on the first terahertz detection signal and the three-dimensional dimension data includes:

[0015] Obtaining the surface scanning detection signals corresponding to the respective thickness layers of the non-metallic pipeline to be detected based on the first terahertz detection signal;

[0016] Respectively obtaining surface images corresponding to the respective thickness layers based on the respective surface scanning detection signals;

[0017] Superimposing the respective surface images to obtain an initial three-dimensional structure of the defect in the non-metallic pipeline to be detected;

[0018] Overlaying the three-dimensional dimension data in the initial three-dimensional structure to obtain the target three-dimensional structure of the defect in the non-metallic pipeline to be detected.

[0019] In the embodiment of the present application, obtaining the first terahertz detection waveform of the non-metallic pipeline to be detected based on the first terahertz detection signal includes:

[0020] Obtaining an initial terahertz detection waveform of the non-metallic pipeline to be detected based on the first terahertz detection signal;

[0021] Performing optimization processing on the initial terahertz detection waveform to obtain the first terahertz detection waveform of the non-metallic pipeline to be detected.

[0022] In the embodiment of the present application, after constructing the target three-dimensional structure of the defect in the non-metallic pipeline to be detected, the detection method further includes: outputting a detection report of the non-metallic pipeline to be detected.

[0023] The second aspect of the present application provides a non-metallic pipeline defect detection system based on terahertz, and the detection system includes:

[0024] A signal acquisition module, configured to acquire a first terahertz detection signal of a non-metallic pipeline to be detected;

[0025] A signal processing module, configured to obtain a first terahertz detection waveform of the non-metallic pipeline to be detected based on the first terahertz detection signal;

[0026] A defect type identification module, configured to obtain the correspondence between defect types and terahertz detection waveforms from a preset database, and determine a target defect type corresponding to the defect in the non-metallic pipeline to be detected based on the first terahertz detection waveform and the correspondence; wherein, in the correspondence, each defect type corresponds to three types of detection waveforms, and the three types of detection waveforms include single-point scanning detection waveforms, line scanning detection waveforms, and surface scanning detection waveforms;

[0027] A defect three-dimensional size calculation module, configured to determine three-dimensional size data of the defect in the non-metallic pipeline to be detected based on the target defect type and the first terahertz detection signal;

[0028] A defect three-dimensional reconstruction module, configured to construct a target three-dimensional structure of the defect in the non-metallic pipeline to be detected based on the first terahertz detection signal and the three-dimensional size data.

[0029] In an embodiment of the present application, the detection system further includes a scanning control module,

[0030] The scanning control module is configured to control the terahertz probe to scan the non-metallic pipeline to be detected according to a preset scanning path to generate the first terahertz detection signal;

[0031] The scanning control module is further configured to receive relevant parameter settings to form the preset scanning path. In an embodiment of the present application, the defect three-dimensional reconstruction module is configured to obtain surface scanning detection signals corresponding to respective thickness layers of the non-metallic pipeline to be detected based on the first terahertz detection signal; obtain surface images corresponding to the respective thickness layers based on the respective surface scanning detection signals; superimpose the respective surface images to obtain an initial three-dimensional structure of the defect in the non-metallic pipeline to be detected; and superimpose the three-dimensional size data on the initial three-dimensional structure to obtain the target three-dimensional structure of the defect in the non-metallic pipeline to be detected.

[0032] In an embodiment of the present application, the detection system further includes:

[0033] A report generation module, configured to output a detection report of the non-metallic pipeline to be detected.

[0034] A third aspect of the present application provides a non-metallic pipeline defect detection device based on terahertz. The detection device includes a terahertz probe, a signal collector, a signal processor, and a detection tooling;

[0035] The terahertz probe, the signal collector, and the signal processor are connected in sequence, and the terahertz probe is disposed on the detection tooling;

[0036] The terahertz probe is used to scan the non-metallic pipeline to be detected;

[0037] The detection tooling is used to drive the terahertz probe to scan the non-metallic pipeline to be detected according to a preset scanning path;

[0038] The signal collector is used to receive and store the first terahertz detection signal fed back by the terahertz probe;

[0039] The signal processor is used to obtain the first terahertz detection signal from the signal collector, and based on the first terahertz detection signal, obtain the first terahertz detection waveform of the non-metallic pipeline to be detected; obtain the correspondence between the defect type and the terahertz detection waveform from a preset database, and based on the first terahertz detection waveform and the correspondence, determine the target defect type corresponding to the defect in the non-metallic pipeline to be detected; based on the target defect type and the first terahertz detection signal, determine the three-dimensional dimension data of the defect in the non-metallic pipeline to be detected; based on the first terahertz detection signal and the three-dimensional dimension data, construct the target three-dimensional structure of the defect in the non-metallic pipeline to be detected; wherein, in the correspondence, each defect type corresponds to three types of detection waveforms, and the three types of detection waveforms include single-point scanning detection waveforms, line scanning detection waveforms, and surface

[0040] scanning detection waveforms.

[0041] Through the above technical solution, the technical solution includes: obtaining the first terahertz detection signal of the non-metallic pipeline to be detected; based on the first terahertz detection signal, obtaining the first terahertz detection waveform of the non-metallic pipeline to be detected; obtaining the correspondence between the defect type and the terahertz detection waveform from a preset database, and based on the first terahertz detection waveform and the correspondence, determining the target defect type corresponding to the defect in the non-metallic pipeline to be detected; wherein, in the correspondence, each defect type corresponds to three types of detection waveforms, and the three types of detection waveforms include single-point scanning detection waveforms, line scanning detection waveforms, and surface scanning detection waveforms; based on the target defect type and the first terahertz detection signal, determining the three-dimensional dimension data of the defect in the non-metallic pipeline to be detected; based on the first terahertz detection signal and the three-dimensional dimension data, constructing the target three-dimensional structure of the defect in the non-metallic pipeline to be detected. Thereby, a relatively complete and mature terahertz detection method can be provided for non-metallic pipelines, facilitating the popularization of terahertz detection means in the field of non-metallic pipeline detection.

[0042] Other features and advantages of the embodiments of the present application will be described in detail in the following specific implementation part. Brief Description of the Drawings

[0043] The drawings are used to provide a further understanding of the embodiments of the present application, and constitute a part of the specification. Together with the following specific implementation, they are used to explain the embodiments of the present application, but do not constitute a limitation to the embodiments of the present application. In the drawings:

[0044] Figure 1 Schematically shows a flowchart of a terahertz-based non-metallic pipeline defect detection method according to an embodiment of the present application;

[0045] Figure 2 Schematically shows a structural block diagram of a terahertz-based non-metallic pipeline defect detection system according to an embodiment of the present application;

[0046] Figure 3 Schematically shows another terahertz-based non-metallic pipeline

[0047] structural block diagram of the defect detection system;

[0048] Figure 4 Schematically shows a structural diagram of a terahertz-based non-metallic pipeline defect detection device according to an embodiment of the present application.

[0049] Description of the Reference Numerals in the Drawings

[0050] 200 - Terahertz-based non-metallic pipeline defect detection system; 210 - Signal acquisition module; 220 - Signal processing module; 230 - Defect type identification module; 240 - Defect three-dimensional size calculation module; 250 - Defect three-dimensional reconstruction module; 260 - Scanning control module; 270 - Defect database; 280 - Report generation module. Detailed Description of the Embodiments

[0051] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. It should be understood that the specific implementation described here is only used to illustrate and explain the embodiments of the present application, and is not used to limit the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present application.

[0052] It should be noted that if there are directional indications (such as up, down, left, right, front, back...) involved in the embodiments of this application, then such directional indications are only used to explain the relative positional relationship, movement conditions, etc. between components in a specific posture (as shown in the drawings). If this specific posture changes, then the directional indications will also change accordingly.

[0053] In addition, if there are descriptions such as "first", "second", etc. involved in the embodiments of this application, then such descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0054] As described in the background art, non-metallic pipes have been widely used as conveying pipelines in fields such as petroleum, chemical industry, and urban gas. With the increasing proportion of non-metallic pipelines, the defect detection of non-metallic pipelines is crucial for ensuring safe transportation. Terahertz electromagnetic waves are suitable as a detection means for non-metallic pipelines due to their good penetration, low energy, transient nature, high resolution, non-contact, etc. characteristics. However, for non-metallic pipelines, there is currently no relatively perfect and mature terahertz detection method, resulting in the hindrance of the popularization and development of terahertz detection means in the field of non-metallic pipeline detection.

[0055] Embodiment 1

[0056] In view of this, in one embodiment of this application, a terahertz-based non-metallic pipeline defect detection method is provided. This detection method can use terahertz electromagnetic waves to detect defects in non-metallic pipelines. In practical applications, this detection method can be executed by a signal processor. As Figure 1 shown, this terahertz-based non-metallic pipeline defect detection method may include the following steps:

[0057] Step 101: Obtain a first terahertz detection signal of the non-metallic pipeline to be detected.

[0058] In the embodiments of this application, the first terahertz detection signal may be generated by a terahertz probe scanning the non-metallic pipeline to be detected according to a preset scanning path.

[0059] Among them, the preset scanning path includes: starting from the scanning starting point, performing line scanning along the axis direction of the non-metal pipeline to be detected; after each line scanning is completed, stepping a preset distance along the circumferential direction of the non-metal pipeline to be detected, and then performing line scanning along the axis direction of the non-metal pipeline to be detected again. Specifically, starting from the scanning starting point, the terahertz probe performs the first line scanning along the axis direction of the non-metal pipeline to be detected; after the first line scanning is completed, taking the end point of the first line scanning as the stepping starting point, the terahertz probe steps a preset distance along the circumferential direction of the non-metal pipeline to be detected to the stepping end point; taking this stepping end point as the new scanning starting point, the terahertz probe performs the second line scanning along the axis direction of the non-metal pipeline to be detected; after the second line scanning is completed, taking the end point of the second line scanning as the stepping starting point, the terahertz probe steps a preset distance along the circumferential direction of the non-metal pipeline to be detected to the stepping end point; taking this stepping end point as the new scanning starting point, the terahertz probe performs the third line scanning along the axis direction of the non-metal pipeline to be detected... and so on, until area scanning is realized through the coverage of the line scanning path, and then the scanning of the range to be detected in the non-metal pipeline to be detected is completed.

[0060] In the above embodiment, the line scanning can be linear scanning or curve scanning. In any two adjacent line scans, the scanning moving direction of the terahertz probe is opposite; for example, in the first line scan, the terahertz probe moves from the first end to the second end of the non-metal pipeline to be detected; in the second line scan, the terahertz probe moves from the second end to the first end of the non-metal pipeline to be detected, and in the third line scan, the terahertz probe moves from the first end to the second end of the non-metal pipeline to be detected... In addition, during the process of the terahertz probe stepping a preset distance between two line scans, terahertz electromagnetic waves may not be emitted.

[0061] Step 102, based on the first terahertz detection signal, obtain the first terahertz detection waveform of the non-metal pipeline to be detected.

[0062] In specific implementation, first, based on the first terahertz detection signal, obtain the initial terahertz detection waveform of the non-metal pipeline to be detected; then perform optimization processing on the initial terahertz detection waveform, and further obtain the first terahertz detection waveform of the non-metal pipeline to be detected.

[0063] Among them, the initial terahertz detection waveform can be optimized and processed by inverse convolution transform, Fourier transform, Laplace transform, wavelet transform, Kalman filter, etc. for filtering, time-domain to frequency-domain transformation, etc., so that the first terahertz detection waveform obtained after processing can more clearly reflect the waveform characteristics at the defect of the non-metal pipeline to be detected.

[0064] Step 103: Obtain the correspondence between defect types and terahertz detection waveforms from a preset database. Based on the first terahertz detection waveform and the correspondence, determine the target defect type corresponding to the defect in the non-metallic pipeline to be detected.

[0065] The preset database can also be referred to as a defect database, which stores the correspondence between various defect types and terahertz detection waveforms. This correspondence can be established based on historical detection data or imported from the outside. Among them, the defect types can include lack of fusion defects, inclusion defects, porosity defects, and cold welding defects, etc.

[0066] Considering that the defect types that appear in non-metallic pipelines of different materials may also be different, various non-metallic pipelines of different materials and various defect types can be stored correspondingly in the preset database. Furthermore, when determining the target defect type corresponding to the defect in the non-metallic pipeline to be detected based on the first terahertz detection waveform and the correspondence, the defect type range can be narrowed down based on the material of the non-metallic pipeline to be detected first, and then based on the first terahertz detection waveform and the correspondence, the defect type corresponding to the first terahertz detection waveform can be determined from the narrowed defect type range, which is the target defect type corresponding to the defect in the non-metallic pipeline to be detected.

[0067] To further improve the feasibility of Step 103, in the correspondence, each defect type can correspond to three types of detection waveforms, and the three types of detection waveforms include single-point scanning detection waveforms, line scanning detection waveforms, and area scanning detection waveforms. Thus, whether the first terahertz detection waveform is a single-point scanning detection waveform, a line scanning detection waveform, or an area scanning detection waveform, the defect type corresponding to the first terahertz detection waveform can be determined based on the correspondence.

[0068] Step 104: Based on the target defect type and the first terahertz detection signal, determine the three-dimensional size data of the defect in the non-metallic pipeline to be detected.

[0069] Considering that the defect size calculation methods corresponding to different defect types may be different. Therefore, based on the target defect type and the first terahertz detection signal, determining the three-dimensional size data of the defect in the non-metallic pipeline to be detected can specifically be based on the calculation method corresponding to the target defect type and the first terahertz detection signal to determine the three-dimensional size data of the defect in the non-metallic pipeline to be detected. Among them, the three-dimensional size data can include the size data of the defect in the axial direction, the size data of the defect in the circumferential direction, and the size data of the defect in the pipeline thickness direction.

[0070] The specific calculation principle of the three-dimensional dimension data can be referred to the application document with the application number 202111595433.2, which will not be elaborated here.

[0071] Step 105: Based on the first terahertz detection signal and the three-dimensional dimension data, construct the target three-dimensional structure of the defect in the non-metallic pipeline to be detected.

[0072] In the embodiment of the present application, step 105 may specifically include: obtaining the surface scanning detection signals corresponding to each thickness layer of the non-metallic pipeline to be detected based on the first terahertz detection signal; respectively obtaining the surface images corresponding to each thickness layer based on the surface scanning detection signals; superimposing the surface images to obtain the initial three-dimensional structure of the defect in the non-metallic pipeline to be detected; and superimposing the three-dimensional dimension data on the initial three-dimensional structure to obtain the target three-dimensional structure of the defect in the non-metallic pipeline to be detected.

[0073] Among them, the initial three-dimensional structure only shows the shape of the defect. By further superimposing the three-dimensional dimension data on the initial three-dimensional structure, a three-dimensional structure image of the defect with dimension markings can be obtained.

[0074] In order to facilitate technicians to consult the detection results of the non-metallic pipeline to be detected, in practical applications, after constructing the target three-dimensional structure of the defect in the non-metallic pipeline to be detected, the detection method provided in the embodiment of the present application further includes: outputting a detection report of the non-metallic pipeline to be detected. The detection report may include the defect type, three-dimensional dimension data, three-dimensional structure image, etc. of the defect in the non-metallic pipeline to be detected.

[0075] It can be understood that the terahertz-based non-metallic pipeline defect detection method provided in the embodiment of the present application includes: obtaining the first terahertz detection signal of the non-metallic pipeline to be detected; obtaining the first terahertz detection waveform of the non-metallic pipeline to be detected based on the first terahertz detection signal; obtaining the correspondence between the defect type and the terahertz detection waveform from the preset database, and determining the target defect type corresponding to the defect in the non-metallic pipeline to be detected based on the first terahertz detection waveform and the correspondence; determining the three-dimensional dimension data of the defect in the non-metallic pipeline to be detected based on the target defect type and the first terahertz detection signal; and constructing the target three-dimensional structure of the defect in the non-metallic pipeline to be detected based on the first terahertz detection signal and the three-dimensional dimension data. Thus, a relatively complete and mature terahertz detection method can be provided for non-metallic pipelines, facilitating the popularization of terahertz detection means in the field of non-metallic pipeline detection.

[0076] On the other hand, existing terahertz detection methods are mostly designed specifically for a single product structure and are difficult to detect other structures. However, the terahertz-based non-metallic pipeline defect detection method provided in the above embodiments of the present application is universal and can detect various detection objects.

[0077] Embodiment 2

[0078] Based on the same inventive concept, another embodiment of the present application further provides a terahertz-based non-metallic pipeline defect detection system 200, as Figure 2 shown; Figure 2 The structural block diagram of the terahertz-based non-metallic pipeline defect detection system 200 is schematically shown. The terahertz-based non-metallic pipeline defect detection system 200 may include a signal acquisition module 210, a signal processing module 220, a defect type identification module 230, a defect three-dimensional size calculation module 240, and a defect three-dimensional reconstruction module 250. In practical applications, the signal acquisition module 210, the signal processing module 220, the defect type identification module 230, the defect three-dimensional size calculation module 240, and the defect three-dimensional reconstruction module 250 may be built into the signal processor. In the terahertz-based non-metallic pipeline defect detection system 200:

[0079] The signal acquisition module 210 can be used to acquire the first terahertz detection signal of the non-metallic pipeline to be detected.

[0080] Among them, the first terahertz detection signal may be generated by the terahertz probe scanning the non-metallic pipeline to be detected according to a preset scanning path. The preset scanning path includes: starting from the scanning starting point, performing line scanning along the axial direction of the non-metallic pipeline to be detected; after each line scanning is completed, stepping a preset distance along the circumferential direction of the non-metallic pipeline to be detected, and then performing line scanning along the axial direction of the non-metallic pipeline to be detected again.

[0081] For the convenience of controlling the scanning process of the terahertz probe, in one implementation, as Figure 3 shown, the detection system 200 provided in the embodiments of the present application may further include a scanning control module 260. The scanning control module 260 can be used to control the terahertz probe to scan the non-metallic pipeline to be detected according to a preset scanning path to generate the first terahertz detection signal; in addition, the scanning control module 260 can also be used to receive relevant parameter settings to form the preset scanning path.

[0082] Specifically, the scan control module 260 can provide a function for adjusting the position of the terahertz probe. Technicians can move the terahertz probe to the starting point based on the scan control module 260 and set this starting point as the scan start point. After receiving the setting of the scan start point, the scan control module 260 can reset the displacement and scan time of the terahertz probe to zero. Further, technicians can input relevant parameter settings in the scan control module 260, including setting the scan path of the terahertz probe, the scan range, the scan speed when the terahertz probe performs line scanning, the specific distance and speed at which the terahertz probe steps along the circumferential direction of the non-metallic pipeline to be detected, etc. Furthermore, the scan control module 260 can control the terahertz probe to scan the non-metallic pipeline to be detected according to the preset scan path, preset scan range, and preset speed.

[0083] The terahertz probe is a general term for a terahertz signal transmitter and a receiver. During the scanning process, the terahertz signal transmitter can emit continuous terahertz pulses, which are incident on the surface of the non-metallic pipeline to be detected. The terahertz signal receiver can receive the terahertz signals reflected from the non-metallic pipeline. The terahertz signal receiver can also feedback the received terahertz signals to the signal collector in the form of voltage signals or current signals and store them in the signal collector, specifically in CVS format.

[0084] Therefore, in the embodiment of the present application, the signal acquisition module 210 can acquire the first terahertz detection signal from the signal collector. In specific implementation, the signal acquisition module 210 can acquire the first terahertz detection signal from the signal collector in real time, and then the subsequent relevant data processing processes based on the first terahertz detection signal can also be carried out in real time. The signal acquisition module 210 can also acquire the first terahertz detection signal from the signal collector after the detection is completed.

[0085] The signal processing module 220 can be used to obtain the first terahertz detection waveform of the non-metallic pipeline to be detected based on the first terahertz detection signal.

[0086] In an embodiment of the present application, after obtaining the first terahertz detection signal, the specific processing process of the signal processing module 220 for the first terahertz detection signal may include: based on the first terahertz detection signal, first obtaining an initial terahertz detection waveform of the non-metallic pipeline to be detected; then, performing an optimization process on the initial terahertz detection waveform to obtain a first terahertz detection waveform of the non-metallic pipeline to be detected. Among them, the initial terahertz detection waveform can be optimized by processes such as deconvolution integral transform, Fourier transform, Laplace transform, wavelet transform, Kalman filter, etc., for filtering, time-domain to frequency-domain transformation, etc., so that the first terahertz detection waveform obtained after processing can more clearly reflect the waveform characteristics of the defect of the non-metallic pipeline to be detected.

[0087] The defect type recognition module 230 can be used to obtain the correspondence between the defect type and the terahertz detection waveform from a preset database, and determine the target defect type corresponding to the defect in the non-metallic pipeline to be detected based on the first terahertz detection waveform and the correspondence; among them, in the correspondence, each defect type corresponds to three types of detection waveforms, and the three types of detection waveforms include single-point scan detection waveforms, line scan detection waveforms, and surface scan detection waveforms.

[0088] The preset database stores the correspondence between various defect types and terahertz detection waveforms; this correspondence can be established based on historical detection data or imported from the outside. Among them, the defect types can include lack of fusion defects, inclusion defects, porosity defects, and cold welding defects, etc.

[0089] In an embodiment of the present application, the defect type recognition module 230 can first determine the target terahertz detection waveform that matches the first terahertz detection waveform, and further, the defect type corresponding to the target terahertz detection waveform is the target defect type corresponding to the defect in the non-metallic pipeline to be detected.

[0090] Considering that the defect types that appear in non-metallic pipelines of different materials may also be different, the preset database can further store the correspondence between various non-metallic pipeline materials and various defect types. Furthermore, when determining the target defect type corresponding to the defect in the non-metallic pipeline to be detected based on the first terahertz detection waveform and the correspondence, the defect type range can be narrowed first based on the material of the non-metallic pipeline to be detected, and then based on the first terahertz detection waveform and the correspondence, the defect type corresponding to the first terahertz detection waveform is determined from the narrowed defect type range, which is the target defect type corresponding to the defect in the non-metallic pipeline to be detected.

[0091] To further improve the feasibility, in the corresponding relationship, each defect type can correspond to three types of detection waveforms, including single-point scanning detection waveform, line scanning detection waveform, and surface scanning detection waveform. Thus, regardless of whether the first terahertz detection waveform is a single-point scanning detection waveform, a line scanning detection waveform, or a surface scanning detection waveform, the defect type corresponding to the first

[0092] terahertz detection waveform can be determined based on the corresponding relationship.

[0093] The preset database can also be referred to as a defect database. The detection system 200 provided in the embodiment of the present application can also include a defect database 270, as Figure 3 shown. After each detection is completed, the first terahertz detection waveform and the corresponding target defect type can be input into the defect database 270. Therefore, in addition to having a storage function and storing the above corresponding relationship, the defect database 270 also has a big data learning function, and can, with the increase of terahertz detection waveforms, adopt a neural network algorithm to autonomously learn the relationship between the defect type and the terahertz detection waveform, so as to continuously improve the accuracy of defect type recognition.

[0094] The defect three-dimensional size calculation module 240 can be used to determine the three-dimensional size data of the defect in the non-metallic pipeline to be detected based on the target defect type and the first terahertz detection signal.

[0095] Considering that the defect size calculation methods corresponding to different defect types may also be different. Therefore, the defect three-dimensional size calculation module 240 can specifically determine the three-dimensional size data of the defect in the non-metallic pipeline to be detected based on the calculation method corresponding to the target defect type and the first terahertz detection signal. Among them, the three-dimensional size data can include the size data of the defect in the axial direction, the size data of the defect in the circumferential direction, and the size data of the defect in the pipeline thickness direction.

[0096] The specific calculation principle of the three-dimensional size data can refer to the application document with the application number 202111595433.2, which will not be elaborated here.

[0097] The defect three-dimensional reconstruction module 250 can be used to construct the target three-dimensional structure of the defect in the non-metallic pipeline to be detected based on the first terahertz detection signal and the three-dimensional size data.

[0098] In the embodiment of the present application, the defect three-dimensional reconstruction module 250 can specifically be used to obtain the surface scanning detection signals corresponding to the respective thickness layers of the non-metallic pipeline to be detected based on the first terahertz detection signal; obtain the surface images corresponding to the respective thickness layers based on the respective surface scanning detection signals; superimpose the respective surface images to obtain the initial three-dimensional structure of the defect in the non-metallic pipeline to be detected; and superimpose the three-dimensional dimension data on the initial three-dimensional structure to obtain the target three-dimensional structure of the defect in the non-metallic pipeline to be detected. Among them, the initial three-dimensional structure only shows the shape of the defect. By further superimposing the three-dimensional dimension data on the initial three-dimensional structure, a three-dimensional structure image of the defect with dimension markings can be obtained. In practical applications, the defect three-dimensional reconstruction module 250 can also have the function of adjusting parameters such as the three-dimensional imaging resolution.

[0099] To facilitate technicians to consult the detection results of the non-metallic pipeline to be detected, the detection system 200 provided in the embodiment of the present application can further include a report generation module 280. After obtaining the target three-dimensional structure of the defect in the non-metallic pipeline to be detected, the report generation module 280 can be used to output the detection report of the non-metallic pipeline to be detected. The detection report can include the defect type, three-dimensional dimension data, three-dimensional structure image, etc. of the defect in the non-metallic pipeline to be detected. The structure, format, content, etc. of the detection report can be set according to requirements, or can be selected from the report formats provided by the system. For example, technicians can input specific information of the report content, such as detection time, personnel, location, attribute characteristics of the non-metallic pipeline to be detected, detection purpose, etc. in the report generation module 280, and upload relevant photos during the detection process, and the detection report can be automatically generated after the detection is completed.

[0100] It can be understood that by using the terahertz-based non-metallic pipeline defect detection system provided in the embodiment of the present application, a complete and mature non-metallic pipeline defect detection framework can be formed, meeting the non-metallic pipeline detection requirements in actual engineering, laying a foundation for the engineering application of terahertz defect detection of non-metallic pipelines, and thus facilitating the popularization of terahertz detection means in the field of non-metallic pipeline detection.

[0101] Embodiment 3

[0102] An embodiment of the present application further provides a terahertz-based non-metallic pipeline defect detection device 300, as Figure 4 shown. The terahertz-based non-metallic pipeline defect detection device 300 can include a terahertz probe 310, a signal collector 320, a signal processor 330, and a detection tooling 340. The terahertz probe 310, the signal collector 320, and the signal processor 330 are connected in sequence, and the terahertz probe 310 is arranged on the detection tooling 340; wherein:

[0103] The terahertz probe 310 can be used to scan the non-metallic pipeline A to be detected. The terahertz signal emitter in the terahertz probe 310 can emit continuous terahertz pulses, which are incident on the surface of the non-metallic pipeline; the terahertz signal receiver in the terahertz probe 310 can receive the terahertz signals reflected from the non-metallic pipeline. The terahertz probe 310 can also convert the detected terahertz signals into voltage or current signals and feedback them to the signal collector 320 for processing and storage.

[0104] The detection tooling 340 can be used to drive the terahertz probe 310 to scan the non-metallic pipeline A to be detected according to a preset scanning path. The detection tooling 340 is a driving device for the terahertz probe 310. Based on the settings of the scanning control module 260, the detection tooling 340 can drive the terahertz probe 310 to perform single-point scanning, line scanning, and surface scanning on the non-metallic pipeline according to the set parameters. The specific structure of the detection tooling 340 can be set according to actual needs. For example, the detection tooling 340 can be the structure shown in the patent application with the application number 202311058535.X.

[0105] The signal collector 320 can be used to receive and store the first terahertz detection signal fed back by the terahertz probe 310.

[0106] The signal processor 330 can be used to obtain the first terahertz detection signal from the signal collector 320, and based on the first terahertz detection signal, obtain the first terahertz detection waveform of the non-metallic pipeline to be detected; obtain the correspondence between the defect type and the terahertz detection waveform from a preset database, and based on the first terahertz detection waveform and the correspondence, determine the target defect type corresponding to the defect in the non-metallic pipeline to be detected; based on the target defect type and the first terahertz detection signal, determine the three-dimensional dimension data of the defect in the non-metallic pipeline to be detected; based on the first terahertz detection signal and the three-dimensional dimension data, construct the target three-dimensional structure of the defect in the non-metallic pipeline to be detected; wherein, in the correspondence, each defect type corresponds to three types of detection waveforms, and the three types of detection waveforms include single-point scanning detection waveforms, line scanning detection waveforms, and surface scanning detection waveforms.

[0107] In addition, the detection device 300 of the embodiment of the present application may further include a power supply 350 to supply power to the terahertz probe 310, the signal collector 320, the signal processor 330, and the detection tooling 340. Specifically, the power supply 350 can be respectively connected to the terahertz probe 310, the signal collector 320, the signal processor 330, and the detection tooling 340 through wires. The terahertz probe 310, the signal collector 320, the signal processor 330, and the detection tooling 340 can be connected through signal lines.

[0108] It can be understood that the terahertz-based non-metal pipeline defect detection equipment provided by the embodiments of the present application can provide a complete and mature detection framework for non-metal pipeline defect detection, meet the non-metal pipeline detection requirements in actual engineering, lay a foundation for the engineering application of terahertz defect detection of non-metal pipelines, and thus facilitate the popularization of terahertz detection means in the field of non-metal pipeline detection.

[0109] Embodiment 4

[0110] The following describes the terahertz-based non-metal pipeline defect detection method, system and equipment provided by the present application in conjunction with specific embodiments.

[0111] In the embodiments of the application, the non-metal pipeline to be detected is a polyethylene pipeline with a diameter of DN100, and the detection part is the circumferential weld of the hot melt joint.

[0112] In this embodiment, the power supply is 240V industrial electricity, the terahertz probe is a reflective probe of T-ray5000, the signal collector is a supporting signal collector of T-ray5000, the signal processor is a laptop computer, and the detection tooling adopts the tooling structure proposed in the application number 202311058535.X.

[0113] Connect the power supply to the terahertz probe, signal collector, signal processor and detection tooling through wires respectively, connect the terahertz probe and the signal collector through a signal line, and connect the signal processor to the signal collector and detection tooling through signal lines respectively; install the terahertz probe on the detection tooling.

[0114] The width of the circumferential weld is 20mm, and the detection range includes the circumferential weld and 50mm of the pipe body part on both sides. Therefore, the scanning width of the terahertz probe along the axial direction of the pipeline is 120mm, and the entire circumferential direction of the pipeline part within this scanning width is scanned and detected. The set scanning path is: starting from the scanning starting point, perform line scanning along the axis direction of the non-metal pipeline to be detected; after each line scanning is completed, step a preset distance along the circumferential direction of the non-metal pipeline to be detected, and then perform line scanning along the axis direction of the non-metal pipeline to be detected again. Set the axial line scanning speed to 0.1mm / s, the scanning distance to 120mm, set the circumferential scanning step speed to 1mm / 1200s, and the entire circumferential scanning distance to 314mm.

[0115] Assemble the detection tooling with the polyethylene pipeline to be detected. Adjust the position of the terahertz probe to one side at the 12 o'clock direction of the polyethylene pipeline to be detected. Adjust the angle of the terahertz probe so that the terahertz pulse signal is incident perpendicular to the surface of the polyethylene pipeline to be detected. Adjust the height of the terahertz probe so that the perpendicular distance from it to the surface of the polyethylene pipeline to be detected is 30 mm.

[0116] Click the detection start button on the laptop. During the detection process, the terahertz probe continuously emits terahertz pulse signals and scans the polyethylene pipeline to be detected according to the preset path, range, and speed. Store the received reflected signals in the signal collector. When the detection is completed, the detection tooling drives the terahertz probe to stop at the end position at 12 o'clock. The terahertz probe synchronously stops emitting and receiving terahertz signals, and the signal collector stores the signals formed by the scan in the CVS format.

[0117] During the detection process, perform deconvolution transformation on the detected terahertz signals in real time, observe the waveform of the single-scan signal at the defect, identify the defect type, calculate the three-dimensional size data of the defect, and perform three-dimensional reconstruction on the defect in real time.

[0118] After the detection is completed, input the following information:

[0119] Detection time: * year * month * day;

[0120] Detection personnel: XX;

[0121] Detection location: Section A of the polyethylene pipeline in Oilfield D;

[0122] Non-metallic pipeline characteristics: DN100;

[0123] Detection purpose: Detect whether there are welding defects in the hot melt joints of the polyethylene pipeline.

[0124] Then upload the photos taken during the detection process, and then click to generate a detection report to obtain a detection report including the above input information and the detection results. The detection results include the defect type, the three-dimensional size data of the defect, the three-dimensional structure imaging of the defect, etc.

[0125] Those skilled in the art should understand that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0126] This application is described with reference to the flowcharts and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the present application. It should be understood that each flow and / or block in the flowchart and / or block diagram, and combinations of flows and / or blocks in the flowchart and / or block diagram can be implemented by computer program instructions. These computer program instructions can be provided to the processors of general-purpose computers, special-purpose computers, embedded processors, or other programmable data processing devices to generate a machine, such that the instructions executed by the processors of the computer or other programmable data processing devices produce means for implementing the functions specified in one or more of the flows Figure 1 one or more of the flows and / or blocks Figure 1 or means for implementing the functions specified in one or more of the blocks.

[0127] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to operate in a particular manner, such that the instructions stored in the computer-readable memory produce a manufacture including instruction means that implement the functions specified in one or more of the flows Figure 1 one or more of the flows and / or blocks Figure 1 or means for implementing the functions specified in one or more of the blocks.

[0128] These computer program instructions can also be loaded onto a computer or other programmable data processing device, such that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing steps for implementing the functions specified in one or more of the flows Figure 1 one or more of the flows and / or blocks Figure 1 or means for implementing the functions specified in one or more of the blocks.

[0129] In a typical configuration, a computing device includes one or more processors (CPUs), an input / output interface, a network interface, and memory.

[0130] The memory may include non-permanent memory in the form of computer-readable media, random access memory (RAM), and / or non-volatile memory such as read-only memory (ROM) or flash memory. The memory is an example of computer-readable media.

[0131] A computer-readable medium includes permanent and non-permanent, removable and non-removable media, and information storage can be implemented by any method or technology. The information can be computer-readable instructions, data structures, program modules, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassette tapes, magnetic tape magnetic disk storage or other magnetic storage devices, or any other non-transitory medium that can be used to store information that can be accessed by a computing device. As defined herein, a computer-readable medium does not include transitory computer-readable media, such as modulated data signals and carrier waves.

[0132] It should also be noted that the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, such that a process, method, article or apparatus comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or apparatus. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or apparatus comprising the element.

[0133] The above are only embodiments of the present application and are not used to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included within the scope of the claims of the present application.

Claims

1. A terahertz-based non-metallic pipeline defect detection method, characterized in that, The detection method includes: Obtaining a first terahertz detection signal of the non-metallic pipeline to be detected; Based on the first terahertz detection signal, obtaining a first terahertz detection waveform of the non-metallic pipeline to be detected; Obtaining the correspondence between defect types and terahertz detection waveforms from a preset database, and based on the first terahertz detection waveform and the correspondence, determining the target defect type corresponding to the defect in the non-metallic pipeline to be detected; wherein, in the correspondence, each defect type corresponds to three types of detection waveforms, and the three types of detection waveforms include single-point scanning detection waveforms, line scanning detection waveforms, and surface scanning detection waveforms; Based on the target defect type and the first terahertz detection signal, determining the three-dimensional dimension data of the defect in the non-metallic pipeline to be detected; Based on the first terahertz detection signal and the three-dimensional dimension data, constructing a target three-dimensional structure of the defect in the non-metallic pipeline to be detected.

2. The terahertz-based non-metal pipeline defect detection method according to claim 1, wherein The first terahertz detection signal is generated by a terahertz probe scanning the non-metallic pipeline to be detected according to a preset scanning path, and the preset scanning path includes: Starting from the scanning starting point, performing line scanning along the axial direction of the non-metallic pipeline to be detected; After each line scanning is completed, stepping a preset distance along the circumferential direction of the non-metallic pipeline to be detected, and then performing line scanning along the axial direction of the non-metallic pipeline to be detected again.

3. The terahertz-based non-metallic pipeline defect detection method according to claim 1, wherein The constructing a target three-dimensional structure of the defect in the non-metallic pipeline to be detected based on the first terahertz detection signal and the three-dimensional dimension data includes: Based on the first terahertz detection signal, obtaining surface scanning detection signals corresponding to respective thickness layers of the non-metallic pipeline to be detected; Based on the respective surface scanning detection signals, obtaining respective surface images corresponding to the thickness layers; Superimposing the respective surface images to obtain an initial three-dimensional structure of the defect in the non-metallic pipeline to be detected; Superimposing the three-dimensional dimension data on the initial three-dimensional structure to obtain a target three-dimensional structure of the defect in the non-metallic pipeline to be detected.

4. The terahertz-based non-metallic pipeline defect detection method according to claim 1, characterized in that The obtaining a first terahertz detection waveform of the non-metallic pipeline to be detected based on the first terahertz detection signal includes: Based on the first terahertz detection signal, obtaining an initial terahertz detection waveform of the non-metallic pipeline to be detected; Performing optimization processing on the initial terahertz detection waveform to obtain a first terahertz detection waveform of the non-metallic pipeline to be detected.

5. The terahertz-based non-metallic pipeline defect detection method according to claim 1, characterized in that After constructing the target three-dimensional structure of the defect in the non-metallic pipeline to be detected, the detection method further includes: outputting a detection report of the non-metallic pipeline to be detected.

6. A terahertz-based non-metal pipe defect detection system, characterized in that, The detection system includes: A signal acquisition module, configured to acquire a first terahertz detection signal of the non-metallic pipeline to be detected; A signal processing module, configured to obtain a first terahertz detection waveform of the non-metallic pipeline to be detected based on the first terahertz detection signal; A defect type identification module, configured to obtain the correspondence between defect types and terahertz detection waveforms from a preset database, and determine the target defect type corresponding to the defect in the non-metallic pipeline to be detected based on the first terahertz detection waveform and the correspondence; wherein, in the correspondence, each defect type corresponds to three types of detection waveforms, and the three types of detection waveforms include single-point scanning detection waveforms, line scanning detection waveforms, and surface scanning detection waveforms; A defect three-dimensional dimension calculation module, configured to determine the three-dimensional dimension data of the defect in the non-metallic pipeline to be detected based on the target defect type and the first terahertz detection signal; A defect three-dimensional reconstruction module, configured to construct the target three-dimensional structure of the defect in the non-metallic pipeline to be detected based on the first terahertz detection signal and the three-dimensional dimension data; 7. The terahertz-based non-metallic pipeline defect detection system according to claim 6, wherein The detection system further includes a scanning control module, The scanning control module is configured to control the terahertz probe to scan the non-metallic pipeline to be detected according to a preset scanning path to generate the first terahertz detection signal; The scanning control module is further configured to receive relevant parameter settings to form the preset scanning path.

8. The terahertz-based non-metallic pipeline defect detection system according to claim 6, wherein, The defect three-dimensional reconstruction module is configured to obtain the surface scanning detection signals corresponding to the respective thickness layers of the non-metallic pipeline to be detected based on the first terahertz detection signal; obtain the surface imaging corresponding to each thickness layer based on the respective surface scanning detection signals; superimpose the surface imaging to obtain the initial three-dimensional structure of the defect in the non-metallic pipeline to be detected; and superimpose the three-dimensional dimension data on the initial three-dimensional structure to obtain the target three-dimensional structure of the defect in the non-metallic pipeline to be detected.

9. The terahertz-based non-metal pipeline defect detection system according to claim 6, wherein, The detection system further includes: A report generation module, configured to output a detection report of the non-metallic pipeline to be detected.

10. A terahertz-based non-metallic pipeline defect detection device, characterized in that, The detection device includes a terahertz probe, a signal collector, a signal processor, and a detection tooling; The terahertz probe, the signal collector, and the signal processor are connected in sequence, and the terahertz probe is disposed on the detection tooling; The terahertz probe is configured to scan the non-metallic pipeline to be detected; The detection tooling is configured to drive the terahertz probe to scan the non-metallic pipeline to be detected according to a preset scanning path; The signal collector is configured to receive and store the first terahertz detection signal fed back by the terahertz probe; The signal processor is used to obtain the first terahertz detection signal from the signal collector, and based on the first terahertz detection signal, obtain the first terahertz detection waveform of the non-metallic pipeline to be detected; obtain the correspondence between the defect type and the terahertz detection waveform from a preset database, and based on the first terahertz detection waveform and the correspondence, determine the target defect type corresponding to the defect in the non-metallic pipeline to be detected; based on the target defect type and the first terahertz detection signal, determine the three-dimensional dimension data of the defect in the non-metallic pipeline to be detected; based on the first terahertz detection signal and the three-dimensional dimension data, construct the target three-dimensional structure of the defect in the non-metallic pipeline to be detected; wherein, in the correspondence, each defect type corresponds to three types of detection waveforms, and the three types of detection waveforms include single-point scanning detection waveforms, line scanning detection waveforms, and surface scanning detection waveforms.

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