Terahertz-based non-metal pipeline defect detection method, system and device

Abstract

A terahertz-based non-metal pipeline defect detection method, system and device. The detection method comprises: acquiring a first terahertz detection signal of a non-metal pipeline to be subjected to detection (101); on the basis of the first terahertz detection signal, obtaining a first terahertz detection waveform (102); acquiring from a preset database a correspondence between defect types and terahertz detection waveforms, and on the basis of the first terahertz detection waveform and the correspondence, determining a target defect type corresponding to a defect in the pipeline, wherein each defect type corresponds to three detection waveforms (103); on the basis of the target defect type and the first terahertz detection signal, determining three-dimensional size data of the defect (104); and on the basis of the first terahertz detection signal and the three-dimensional size data, constructing a target three-dimensional structure of the defect (105). Therefore, a relatively perfect and developed terahertz detection method can be provided for a non-metal pipeline, thereby facilitating the promotion of a terahertz detection means in the field of non-metal pipeline detection.

Description

Terahertz-based non-metallic pipeline defect detection method, system and equipment

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of Chinese patent application 202311797636.9 filed on December 25, 2023, the contents of which are incorporated herein by reference. Technical Field

[0003] The present invention relates to the field of non-destructive testing technology, and in particular to a terahertz-based non-metallic pipeline defect detection method, a terahertz-based non-metallic pipeline defect detection system, and a terahertz-based non-metallic pipeline defect detection device. Background Art

[0004] To address the corrosion issues of carbon steel pipes, non-metallic pipes have been widely used as pipelines in the petroleum, chemical, and urban gas industries. As the proportion of non-metallic pipes increases, defect detection in non-metallic pipes is crucial to ensuring safe transportation.

[0005] Terahertz electromagnetic waves are suitable for non-metallic pipeline inspection due to their excellent penetration, low energy, transient nature, high resolution, and non-contact nature. However, a comprehensive and mature terahertz inspection method for non-metallic pipelines is currently lacking, hindering the promotion and development of terahertz inspection methods in this field. Summary of the Invention

[0006] The purpose of the present invention is to overcome the problem of the lack of a complete and mature terahertz detection method for non-metallic pipelines in the prior art, and to provide a terahertz-based non-metallic pipeline defect detection method, system and equipment.

[0007] In order to achieve the above objectives, the present invention provides a first aspect of a terahertz-based non-metallic pipeline defect detection method, the detection method comprising:

[0008] Acquire a first terahertz detection signal of the non-metallic pipeline to be detected;

[0009] obtaining a first terahertz detection waveform of the non-metallic pipe to be detected based on the first terahertz detection signal;

[0010] Obtaining a correspondence between defect types and terahertz detection waveforms from a preset database, and determining a target defect type corresponding to the defect in the non-metallic pipe to be detected based on the first terahertz detection waveform and the correspondence; wherein each defect type in the correspondence corresponds to three types of detection waveforms, the three types of detection waveforms including a single-point scanning detection waveform, a line scanning detection waveform, and a surface scanning detection waveform;

[0011] Determining three-dimensional size data of the defect in the non-metallic pipe to be detected based on the target defect type and the first terahertz detection signal;

[0012] Based on the first terahertz detection signal and the three-dimensional size data, a target three-dimensional structure of the defect in the non-metallic pipeline to be detected is constructed.

[0013] In an embodiment of the present application, the first terahertz detection signal is generated by the terahertz probe scanning the non-metallic pipe to be detected according to a preset scanning path, and the preset scanning path includes:

[0014] Starting from the scanning starting point, a line scan is performed along the axis direction of the non-metallic pipe to be inspected;

[0015] After each line scan is completed, a preset distance is stepped along the circumferential direction of the non-metallic pipe to be detected, and a line scan is performed again along the axial direction of the non-metallic pipe to be detected.

[0016] In an embodiment of the present application, constructing a target three-dimensional structure of the defect in the non-metallic pipe to be detected based on the first terahertz detection signal and the three-dimensional size data includes:

[0017] Obtaining surface scanning detection signals corresponding to each thickness layer of the non-metallic pipe to be detected based on the first terahertz detection signal;

[0018] Based on the scanning detection signals of each surface, the surface imaging corresponding to each thickness layer is obtained respectively;

[0019] Superimposing the images of each surface to obtain an initial three-dimensional structure of the defect in the non-metallic pipe to be detected;

[0020] The three-dimensional size data is superimposed on the initial three-dimensional structure to obtain a target three-dimensional structure of defects in the non-metallic pipeline to be detected.

[0021] In an embodiment of the present application, obtaining a first terahertz detection waveform of the non-metallic pipe to be detected based on the first terahertz detection signal includes:

[0022] obtaining an initial terahertz detection waveform of the non-metallic pipe to be detected based on the first terahertz detection signal;

[0023] The initial terahertz detection waveform is optimized to obtain a first terahertz detection waveform of the non-metallic pipe to be detected.

[0024] In an embodiment of the present application, after constructing the target three-dimensional structure of defects in the non-metallic pipe to be inspected, the inspection method further includes: outputting an inspection report of the non-metallic pipe to be inspected.

[0025] A second aspect of the present application provides a terahertz-based non-metallic pipeline defect detection system, the detection system comprising:

[0026] A signal acquisition module, configured to acquire a first terahertz detection signal of a non-metallic pipe to be detected;

[0027] a signal processing module, configured to obtain a first terahertz detection waveform of the non-metallic pipe to be detected based on the first terahertz detection signal;

[0028] a defect type identification module, configured to obtain a correspondence between defect types and terahertz detection waveforms from a preset database, and determine, based on the first terahertz detection waveform and the correspondence, a target defect type corresponding to the defect in the non-metallic pipe to be detected; wherein, in the correspondence, each defect type corresponds to three types of detection waveforms, including a single-point scanning detection waveform, a line scanning detection waveform, and a surface scanning detection waveform;

[0029] a defect three-dimensional size calculation module, configured to determine three-dimensional size data of the defect in the non-metallic pipe to be detected based on the target defect type and the first terahertz detection signal;

[0030] A defect three-dimensional reconstruction module is used 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.

[0031] In the embodiment of the present application, the detection system further includes a scanning control module.

[0032] The scanning control module is used to control the terahertz probe to scan the non-metallic pipe to be detected according to a preset scanning path to generate the first terahertz detection signal;

[0033] The scanning control module is further configured to receive relevant parameter settings to form the preset scanning path.

[0034] In an embodiment of the present application, the defect three-dimensional reconstruction module is used to obtain surface scanning detection signals corresponding to each thickness layer of the non-metallic pipe to be detected based on the first terahertz detection signal; based on each surface scanning detection signal, obtain surface imaging corresponding to each thickness layer; superimpose each surface imaging to obtain an initial three-dimensional structure of the defect in the non-metallic pipe to be detected; and superimpose the three-dimensional size data on the initial three-dimensional structure to obtain a target three-dimensional structure of the defect in the non-metallic pipe to be detected.

[0035] In an embodiment of the present application, the detection system further includes:

[0036] The report generation module is used to output the inspection report of the non-metallic pipeline to be inspected.

[0037] A third aspect of the present application provides a terahertz-based non-metallic pipeline defect detection device, the detection device comprising a terahertz probe, a signal collector, a signal processor, and a detection tool;

[0038] The terahertz probe, the signal collector, and the signal processor are connected in sequence, and the terahertz probe is arranged on the detection tooling;

[0039] The terahertz probe is used to scan the non-metallic pipeline to be detected;

[0040] The detection tooling is used to drive the terahertz probe to scan the non-metallic pipe to be detected according to a preset scanning path;

[0041] The signal collector is used to receive and store the first terahertz detection signal fed back by the terahertz probe;

[0042] The signal processor is used to obtain the first terahertz detection signal from the signal collector, and obtain the first terahertz detection waveform of the non-metallic pipe to be detected based on the first terahertz detection signal; 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 pipe to be detected based on the first terahertz detection waveform and the correspondence; determine the three-dimensional size data of the defect in the non-metallic pipe to be detected based on the target defect type and the first terahertz detection signal; and construct the target three-dimensional structure of the defect in the non-metallic pipe to be detected based on the first terahertz detection signal and the three-dimensional size data; 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 waveform, line scanning detection waveform and surface scanning detection waveform.

[0043] Through the above technical solution, the technical solution includes: obtaining a first terahertz detection signal of the non-metallic pipe to be detected; obtaining a first terahertz detection waveform of the non-metallic pipe to be detected based on the first terahertz detection signal; obtaining the correspondence between the defect type and the terahertz detection waveform from a preset database, and determining the target defect type corresponding to the defect in the non-metallic pipe 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; determining the three-dimensional size data of the defect in the non-metallic pipe 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 pipe to be detected based on the first terahertz detection signal and the three-dimensional size data. As a result, a relatively complete and mature terahertz detection method can be provided for non-metallic pipes, thereby facilitating the promotion of terahertz detection methods in the field of non-metallic pipe detection.

[0044] Other features and advantages of the embodiments of the present application will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The accompanying 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 detailed description, they are used to explain the embodiments of the present application but do not constitute a limitation on the embodiments of the present application. In the accompanying drawings:

[0046] FIG1 schematically shows a flow chart of a terahertz-based non-metallic pipeline defect detection method according to an embodiment of the present application;

[0047] FIG2 schematically shows a structural block diagram of a terahertz-based non-metallic pipeline defect detection system according to an embodiment of the present application;

[0048] FIG3 schematically shows a structural block diagram of another terahertz-based non-metallic pipeline defect detection system according to an embodiment of the present application;

[0049] FIG4 schematically shows a structural diagram of a terahertz-based non-metallic pipeline defect detection device according to an embodiment of the present application.

[0050] Description of Reference Numerals

[0051] 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

[0052] To make the purpose, 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 methods described herein are only used to illustrate and explain the embodiments of the present application and are not used to limit the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0053] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly.

[0054] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present application, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the fact that they can be implemented by ordinary technicians in this field. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0055] As described in the background, non-metallic pipes have been widely used as pipelines in the fields of petroleum, chemical industry, and urban gas. As the proportion of non-metallic pipes increases, defect detection in non-metallic pipes is crucial to ensuring safe transportation. Terahertz electromagnetic waves are suitable as a detection method for non-metallic pipes due to their good penetration, low energy, transient nature, high resolution, and non-contact nature. However, there is currently no comprehensive and mature terahertz detection method for non-metallic pipes, which has hindered the promotion and development of terahertz detection methods in the field of non-metallic pipe detection.

[0056] Example 1

[0057] To address this issue, one embodiment of the present application provides a terahertz-based non-metallic pipeline defect detection method. This method can utilize terahertz electromagnetic waves to detect defects in non-metallic pipelines. In practical applications, this detection method can be executed by a signal processor. As shown in Figure 1, this terahertz-based non-metallic pipeline defect detection method may include the following steps:

[0058] Step 101: Acquire a first terahertz detection signal of a non-metallic pipeline to be detected.

[0059] In an embodiment of the present application, the first terahertz detection signal may be generated by a terahertz probe scanning the non-metallic pipe to be detected according to a preset scanning path.

[0060] Among them, the preset scanning path includes: starting from the scanning starting point, performing a line scan along the axial direction of the non-metallic pipe to be detected; after each line scan is completed, stepping a preset distance along the circumferential direction of the non-metallic pipe to be detected, and performing a line scan again along the axial direction of the non-metallic pipe to be detected. Specifically, starting from the scanning starting point, the terahertz probe performs the first line scan along the axial direction of the non-metallic pipe to be detected; after the first line scan is completed, the end point of the first line scan is used as the step starting point, and the terahertz probe steps a preset distance along the circumferential direction of the non-metallic pipe to be detected to the step end point; with the step end point as the new scanning starting point, the terahertz probe performs a second line scan along the axial direction of the non-metallic pipe to be detected; after the second line scan is completed, the end point of the second line scan is used as the step starting point, and the terahertz probe steps a preset distance along the circumferential direction of the non-metallic pipe to be detected to the step end point; with the step end point as the new scanning starting point, the terahertz probe performs a third line scan along the axial direction of the non-metallic pipe to be detected... and so on, until the line scan path is covered to achieve surface scanning, and then the scanning of the to-be-detected range in the non-metallic pipe to be detected is completed.

[0061] In the above embodiment, the line scan can be a straight scan or a curved scan. In any two adjacent line scans, the terahertz probe moves in opposite directions. For example, in the first line scan, the terahertz probe moves from the first end to the second end of the non-metallic pipe to be inspected; in the second line scan, the terahertz probe moves from the second end to the first end of the non-metallic pipe to be inspected; and in the third line scan, the terahertz probe moves from the first end to the second end of the non-metallic pipe to be inspected. Furthermore, the terahertz probe may not emit terahertz electromagnetic waves while stepping a preset distance between two line scans.

[0062] Step 102: Obtain a first terahertz detection waveform of the non-metallic pipe to be detected based on the first terahertz detection signal.

[0063] In a specific implementation, an initial terahertz detection waveform of the non-metallic pipe to be detected can be obtained based on the first terahertz detection signal; then the initial terahertz detection waveform is optimized to obtain a first terahertz detection waveform of the non-metallic pipe to be detected.

[0064] Among them, the initial terahertz detection waveform can be filtered, time domain-frequency domain transformed, and other optimization processes can be performed through inverse convolution transform, Fourier transform, Laplace transform, wavelet transform, Kalman filter, etc., so that the first terahertz detection waveform obtained after processing can more clearly reflect the waveform characteristics of the non-metallic pipeline defect to be detected.

[0065] Step 103 : Obtain a correspondence between a defect type and a terahertz detection waveform from a preset database, and determine a target defect type corresponding to the defect in the non-metallic pipe to be detected based on the first terahertz detection waveform and the correspondence.

[0066] The preset database, also known as a defect database, stores the correspondence between various defect types and terahertz detection waveforms. This correspondence can be established based on historical detection data or imported externally. Defect types may include lack of fusion, inclusions, porosity, and cold welds.

[0067] Considering that non-metallic pipes made of different materials may also present different defect types, the preset database may further store various non-metallic pipe materials in correspondence with various defect types. Furthermore, when determining the target defect type corresponding to the defect in the non-metallic pipe to be detected based on the first terahertz detection waveform and the corresponding relationship, the defect type range can be first narrowed down based on the material of the non-metallic pipe to be detected. Then, based on the first terahertz detection waveform and the corresponding relationship, the defect type corresponding to the first terahertz detection waveform within the narrowed defect type range can be determined, thereby determining the target defect type corresponding to the defect in the non-metallic pipe to be detected.

[0068] To further improve the feasibility of step 103, in the correspondence, each defect type can correspond to three types of detection waveforms: a single-point scanning waveform, a line scanning waveform, and an area scanning waveform. Thus, regardless of whether the first terahertz detection waveform is a single-point scanning waveform, a line scanning waveform, or an area scanning waveform, the defect type corresponding to the first terahertz detection waveform can be determined based on the correspondence.

[0069] Step 104 : determining three-dimensional size data of the defect in the non-metallic pipe to be detected based on the target defect type and the first terahertz detection signal.

[0070] Considering that different defect types may require different defect size calculation methods, the three-dimensional size data of the defect in the non-metallic pipe to be inspected is determined based on the target defect type and the first terahertz detection signal. Specifically, the three-dimensional size data of the defect in the non-metallic pipe to be inspected can be determined based on the calculation method corresponding to the target defect type and the first terahertz detection signal. The three-dimensional size data may 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 pipe thickness direction.

[0071] The specific calculation principle of the three-dimensional size data can be referred to the application document with application number 202111595433.2, which will not be repeated here.

[0072] Step 105 : constructing a target three-dimensional structure of the defect in the non-metallic pipe to be detected based on the first terahertz detection signal and the three-dimensional size data.

[0073] In an embodiment of the present application, step 105 may specifically include: obtaining surface scanning detection signals corresponding to each thickness layer of the non-metallic pipe to be detected based on the first terahertz detection signal; obtaining surface images corresponding to each thickness layer based on each surface scanning detection signal; superimposing each surface image to obtain an initial three-dimensional structure of the defect in the non-metallic pipe to be detected; and superimposing the three-dimensional size data on the initial three-dimensional structure to obtain a target three-dimensional structure of the defect in the non-metallic pipe to be detected.

[0074] The initial three-dimensional structure only shows the shape of the defect. By further superimposing three-dimensional size data on the initial three-dimensional structure, a three-dimensional structure image of the defect with dimension annotations can be obtained.

[0075] To facilitate technical personnel in reviewing the inspection results of the non-metallic pipe to be inspected, in practical applications, after constructing a target three-dimensional structure of defects in the non-metallic pipe to be inspected, the inspection method provided in embodiments of the present application further includes outputting an inspection report for the non-metallic pipe to be inspected. The inspection report may include the defect type, three-dimensional dimension data, a three-dimensional structural image, and other information of the defect in the non-metallic pipe to be inspected.

[0076] It can be understood that the terahertz-based non-metallic pipeline defect detection method provided in the embodiment of the present application includes: obtaining a first terahertz detection signal of the non-metallic pipeline to be detected; obtaining a first terahertz detection waveform of the non-metallic pipeline to be detected based on the first terahertz detection signal; obtaining a correspondence between defect types and terahertz detection waveforms from a preset database, and determining 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; determining 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; and 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 size data. Thus, a relatively complete and mature terahertz detection method can be provided for non-metallic pipelines, thereby facilitating the promotion of terahertz detection methods in the field of non-metallic pipeline detection.

[0077] 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 this application is universal and can be used to detect various detection objects.

[0078] Example 2

[0079] 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 shown in FIG2 ; FIG2 schematically shows a structural block diagram of the terahertz-based non-metallic pipeline defect detection system 200. 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 actual 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 a signal processor. In the terahertz-based non-metallic pipeline defect detection system 200:

[0080] The signal acquisition module 210 can be used to acquire a first terahertz detection signal of the non-metallic pipe to be detected.

[0081] The first terahertz detection signal may be generated by a terahertz probe scanning the non-metallic pipe to be inspected along a preset scanning path. The preset scanning path includes: starting from a scanning starting point, performing a line scan along the axis of the non-metallic pipe to be inspected; after each line scan, stepping a preset distance in the circumferential direction of the non-metallic pipe to be inspected, and performing another line scan along the axis of the non-metallic pipe to be inspected.

[0082] To facilitate control of the scanning process of the terahertz probe, in one embodiment, as shown in FIG3 , the detection system 200 provided in the embodiment of the present application may further include a scanning control module 260. The scanning control module 260 may be configured to control the terahertz probe to scan the non-metallic pipe to be inspected according to a preset scanning path to generate the first terahertz detection signal; in addition, the scanning control module 260 may also be configured to receive relevant parameter settings to form the preset scanning path.

[0083] Specifically, the scanning control module 260 can provide a terahertz probe position adjustment function. Based on the scanning control module 260, the technician can move the terahertz probe to the starting point and set the starting point as the scanning starting point. After receiving the setting of the scanning starting point, the scanning control module 260 can reset the displacement and scanning time of the terahertz probe to zero. Furthermore, the technician can input relevant parameter settings in the scanning control module 260, including setting the scanning path, scanning range, scanning speed of the terahertz probe when performing line scanning, the specific distance and stepping speed of the terahertz probe along the circumferential direction of the non-metallic pipeline to be detected. Furthermore, the scanning control module 260 can control the terahertz probe to scan the non-metallic pipeline to be detected according to the preset scanning path, preset scanning range and preset speed.

[0084] The terahertz probe is a general term for a terahertz signal transmitter and receiver. During scanning, the terahertz signal transmitter can emit continuous terahertz pulses that are incident on the surface of the non-metallic pipe to be inspected, and the terahertz signal receiver can receive the terahertz signal reflected from the non-metallic pipe. The terahertz signal receiver can also feed the received terahertz signal back to the signal collector in the form of a voltage signal or a current signal, which is stored in the signal collector, specifically in CVS format.

[0085] Therefore, in this embodiment of the present application, the signal acquisition module 210 can obtain the first terahertz detection signal from the signal collector. In a specific implementation, the signal acquisition module 210 can obtain the first terahertz detection signal from the signal collector in real time, and the subsequent data processing based on the first terahertz detection signal can also be performed in real time. The signal acquisition module 210 can also obtain the first terahertz detection signal from the signal collector after the detection is completed.

[0086] The signal processing module 220 may be configured to obtain a first terahertz detection waveform of the non-metallic pipe to be detected based on the first terahertz detection signal.

[0087] In an embodiment of the present application, after obtaining the first terahertz detection signal, the signal processing module 220 may specifically process the first terahertz detection signal by: first obtaining an initial terahertz detection waveform of the non-metallic pipe to be detected based on the first terahertz detection signal; then, optimizing the initial terahertz detection waveform to obtain a first terahertz detection waveform of the non-metallic pipe to be detected. The initial terahertz detection waveform may be subjected to filtering, time-domain-frequency domain transformation, and other optimization processes through inverse convolution transform, Fourier transform, Laplace transform, wavelet transform, Kalman filter, or the like, so that the first terahertz detection waveform obtained after processing can more clearly reflect the waveform characteristics of the defect at the non-metallic pipe to be detected.

[0088] The defect type identification 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; 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 waveform, line scanning detection waveform and surface scanning detection waveform.

[0089] 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 externally. Defect types may include lack of fusion, inclusion defects, porosity defects, and cold weld defects.

[0090] In an embodiment of the present application, the defect type identification module 230 can first determine a target terahertz detection waveform that matches the first terahertz detection waveform, and then the defect type corresponding to the target terahertz detection waveform is the target defect type corresponding to the defect in the non-metallic pipe to be detected.

[0091] Considering that non-metallic pipes made of different materials may also present different defect types, the preset database can further store various non-metallic pipe materials in correspondence with various defect types. Furthermore, when determining the target defect type corresponding to the defect in the non-metallic pipe to be detected based on the first terahertz detection waveform and the corresponding relationship, the defect type range can be first narrowed down based on the material of the non-metallic pipe to be detected. Then, based on the first terahertz detection waveform and the corresponding relationship, the defect type corresponding to the first terahertz detection waveform within the narrowed defect type range can be determined. This is then the target defect type corresponding to the defect in the non-metallic pipe to be detected.

[0092] To further improve feasibility, in the described correspondence, each defect type can correspond to three types of detection waveforms: a single-point scanning waveform, a line scanning waveform, and an area scanning waveform. Thus, regardless of whether the first terahertz detection waveform is a single-point scanning waveform, a line scanning waveform, or an area scanning waveform, the defect type corresponding to the first terahertz detection waveform can be determined based on the described correspondence.

[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 shown in Figure 3. 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 that stores the above-mentioned correspondence, the defect database 270 also has a big data learning function. As the number of terahertz detection waveforms increases, it can use a neural network algorithm to autonomously learn the relationship between defect types and terahertz detection waveforms, thereby continuously improving the accuracy of defect type identification.

[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 pipe to be detected based on the target defect type and the first terahertz detection signal.

[0095] Considering that different defect types may require different defect size calculation methods, the three-dimensional defect size calculation module 240 can determine the three-dimensional size data of the defect in the non-metallic pipe to be inspected based on the calculation method corresponding to the target defect type and the first terahertz detection signal. The three-dimensional size data may include the defect's axial size data, the defect's circumferential size data, and the defect's dimensional data along the pipe's thickness.

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

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

[0098] In an embodiment of the present application, the defect 3D reconstruction module 250 can be specifically configured to obtain, based on the first terahertz detection signal, surface scanning detection signals corresponding to each thickness layer of the non-metallic pipe to be inspected; obtain surface images corresponding to each thickness layer based on each surface scanning detection signal; superimpose each surface image to obtain an initial 3D structure of the defect in the non-metallic pipe to be inspected; and superimpose the 3D dimension data on the initial 3D structure to obtain a target 3D structure of the defect in the non-metallic pipe to be inspected. The initial 3D structure only displays the shape of the defect; by further superimposing the 3D dimension data on the initial 3D structure, a 3D structural image of the defect with dimension annotations can be obtained. In practical applications, the defect 3D reconstruction module 250 can also be configured to adjust parameters such as 3D imaging resolution.

[0099] In order to facilitate technical personnel to review the inspection results of the non-metallic pipe to be inspected, the inspection system 200 provided in the embodiment of the present application may also include a report generation module 280. After obtaining the target three-dimensional structure of the defect in the non-metallic pipe to be inspected, the report generation module 280 can be used to output the inspection report of the non-metallic pipe to be inspected. The inspection report may include the defect type, three-dimensional size data, three-dimensional structure image, etc. of the defect in the non-metallic pipe to be inspected. The inspection report structure, format, content, etc. can be set according to demand, or can be selected from the report format provided by the system. For example, technical personnel can enter specific information of the report content in the report generation module 280, such as inspection time, personnel, location, attribute characteristics of the non-metallic pipe to be inspected, inspection purpose, etc., and upload relevant photos during the inspection process. After the inspection is completed, the inspection report can be automatically generated.

[0100] It can be understood that the terahertz-based non-metallic pipeline defect detection system provided in the embodiment of the present application can form a complete and mature non-metallic pipeline defect detection framework, meet the non-metallic pipeline detection needs in actual engineering projects, and lay the foundation for the engineering application of terahertz defect detection of non-metallic pipelines, thereby facilitating the promotion of terahertz detection methods in the field of non-metallic pipeline detection.

[0101] Example 3

[0102] One embodiment of the present application further provides a terahertz-based non-metallic pipeline defect detection device 300, as shown in FIG4 . The terahertz-based non-metallic pipeline defect detection device 300 may include a terahertz probe 310, a signal collector 320, a signal processor 330, and a detection tool 340. The terahertz probe 310, the signal collector 320, and the signal processor 330 are connected in sequence, and the terahertz probe 310 is disposed on the detection tool 340; wherein:

[0103] The terahertz probe 310 can be used to scan the non-metallic pipe A to be inspected. The terahertz signal transmitter in the terahertz probe 310 can emit continuous terahertz pulses that are incident on the surface of the non-metallic pipe. The terahertz signal receiver in the terahertz probe 310 can receive the terahertz signal reflected from the non-metallic pipe. The terahertz probe 310 can also convert the detected terahertz signal into a voltage or current signal and feed it back to the signal collector 320 for processing and storage.

[0104] The inspection fixture 340 can be used to drive the terahertz probe 310 to scan the non-metallic pipe A to be inspected according to a preset scanning path. The inspection fixture 340 is a driving device for the terahertz probe 310. Based on the settings of the scanning control module 260, the inspection fixture 340 can drive the terahertz probe 310 to perform single-point scanning, line scanning, and surface scanning of the non-metallic pipe according to the set parameters. The specific structure of the inspection fixture 340 can be configured according to actual needs. For example, the inspection fixture 340 can be configured as described in Application No. 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 obtain the first terahertz detection waveform of the non-metallic pipe to be detected based on the first terahertz detection signal; 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 pipe to be detected based on the first terahertz detection waveform and the correspondence; determine the three-dimensional size data of the defect in the non-metallic pipe to be detected based on the target defect type and the first terahertz detection signal; construct the target three-dimensional structure of the defect in the non-metallic pipe to be detected based on the first terahertz detection signal and the three-dimensional size data; 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 waveform, line scanning detection waveform and surface scanning detection waveform.

[0107] In addition, the detection device 300 of the embodiment of the present application may also include a power supply 350 to power the terahertz probe 310, the signal acquisition unit 320, the signal processor 330, and the detection tooling 340. Specifically, the power supply 350 may be connected to the terahertz probe 310, the signal acquisition unit 320, the signal processor 330, and the detection tooling 340 via wires. The terahertz probe 310, the signal acquisition unit 320, the signal processor 330, and the detection tooling 340 may be connected to each other via signal lines.

[0108] It can be understood that the terahertz-based non-metallic pipeline defect detection equipment provided in the embodiments of the present application can provide a complete and mature detection framework for non-metallic pipeline defect detection, meet the non-metallic pipeline detection needs in actual projects, and lay the foundation for the engineering application of terahertz defect detection of non-metallic pipelines, thereby facilitating the promotion of terahertz detection methods in the field of non-metallic pipeline detection.

[0109] Example 4

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

[0111] In the application embodiment, the non-metallic pipe to be inspected is a DN100 polyethylene pipe, and the inspection site is the girth weld of the hot melt joint.

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

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

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

[0115] Assemble the detection tooling and the polyethylene pipe to be inspected, adjust the position of the terahertz probe to the 12 o'clock side of the polyethylene pipe to be inspected, adjust the angle of the terahertz probe so that the terahertz pulse signal is incident perpendicular to the surface of the polyethylene pipe to be inspected, and adjust the height of the terahertz probe so that the vertical distance between it and the surface of the polyethylene pipe to be inspected is 30 mm.

[0116] Click the Start button on the laptop. During the test, the terahertz probe continuously emits terahertz pulse signals and scans the polyethylene pipe according to the preset path, range, and speed, storing the received reflected signals in the signal collector. When the test is complete, the inspection tool drives the terahertz probe to stop at the 12 o'clock end position, and the terahertz probe simultaneously stops transmitting and receiving terahertz signals. The signal collector stores the scanned signals in CVS format.

[0117] During the detection process, the terahertz signal obtained by detection is deconvolved in real time, the waveform of the single scanning signal at the defect is observed, the defect type is identified, and the three-dimensional size data of the defect is calculated, and the defect is reconstructed in three dimensions in real time.

[0118] After the test is complete, enter the following information:

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

[0120] Testing personnel: XX;

[0121] Testing location: Section A of polyethylene pipeline in D oil field;

[0122] Non-metallic pipe characteristics: DN100;

[0123] Purpose of inspection: To inspect whether there are welding defects in polyethylene pipe hot melt joints.

[0124] Then upload the photos taken during the inspection process and click Generate Inspection Report to obtain an inspection report that includes the above input information and the inspection results. The inspection results include the defect type, 3D defect size data, and 3D structural imaging of the defect.

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

[0126] The present application is described with reference to the flow chart and / or block diagram of the method, device (system), and computer program product according to the embodiment of the present application. It should be understood that each flow process and / or box in the flow chart and / or block diagram and the combination of the flow process and / or box in the flow chart and / or block diagram can be realized by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processing machine or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device produce a device for realizing the function specified in one flow chart flow or multiple flows and / or one box or multiple boxes of the block diagram.

[0127] These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce a product including an instruction device that implements the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0128] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, so that the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

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

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

[0131] Computer-readable media includes permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology for information storage. 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 technology, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer-readable media does not include transitory computer-readable media such as modulated data signals and carrier waves.

[0132] It should also be noted that the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, commodity, or apparatus that includes a series of elements includes not only those elements but also other elements not explicitly listed, or includes elements inherent to such process, method, commodity, or apparatus. In the absence of further limitations, an element defined by the phrase "comprises a ..." does not exclude the presence of other identical elements in the process, method, commodity, or apparatus that includes the element.

[0133] The above are merely embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should all be included within the scope of the claims of the present application.

Claims

1. A terahertz-based non-metal pipe 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-metallic 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-metal 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 surface images corresponding to the respective 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; Overlaying the three-dimensional dimension data in 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-metal pipeline defect detection method according to claim 1, wherein 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-metallic pipeline defect detection system, characterized in that, The detection system includes: A signal acquisition module for acquiring a first terahertz detection signal of the non-metallic pipeline to be detected; A signal processing module for obtaining a first terahertz detection waveform of the non-metallic pipeline to be detected based on the first terahertz detection signal; A defect type recognition 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 size calculation module, configured 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; 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 size data; 7. The terahertz-based non-metallic pipeline defect detection system according to claim 6, characterized in that 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 along 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-metal 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; stack the surface imaging to obtain the initial three-dimensional structure of the defect in the non-metallic pipeline to be detected; and stack the three-dimensional size 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; 9. The terahertz-based non-metallic pipeline defect detection system according to claim 6, characterized in that, 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-metal pipe 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 along 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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