Defect detection system and defect detection method

Abstract

The invention provides a defect detection system and a defect detection method, and belongs to the technical field of defect detection.The system comprises an ultrasonic detection device and a server, and the ultrasonic detection device comprises a bearing frame; the ultrasonic probe is arranged on the mounting mechanism, and the mounting mechanism is arranged on the bearing frame through a telescopic mechanism; the walking mechanism is arranged on the lower end surface of the bearing frame and is used for generating displacement to change the position of the ultrasonic detection device so as to realize defect detection of different detection areas; the processor is connected with the server, the ultrasonic probe and the walking mechanism, controls the ultrasonic probe and the walking mechanism to work based on the received control instruction, and sends an echo signal to the server; the server is used for sending a control instruction to the processor and determining the defect state of the detection area based on the echo signal, and the defect state comprises defect existence and defect absence. The device is simple in structure, can achieve the accurate detection of the narrow space of the hydroelectric generating set, and is high in detection efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of defect detection, and in particular to a defect detection system and a defect detection method. Background Art

[0002] In the context of the new power system, with the massive access of new energy generation, small and medium-sized hydropower units are facing the situation of deep peak regulation, which will cause the hydro-generator units to frequently pass through the vibration zone, resulting in a significant shortening of the damage cycle of key metal parts of the units. At the same time, during frequent start-stop and low-load operation, the operating reliability of the units will be reduced, causing additional stress and wear on the key components of the units, thereby aggravating their damage and shortening the service life of the units.

[0003] Among them, key components such as the generator center body weld and the runner blade weld will be subjected to large mechanical vibrations and stress changes during frequent startup and shutdown. These frequent vibrations and stress fluctuations will cause stress concentration inside the components. Small cracks are easily formed in the early stage due to the original small defects inside the metal components. With the operation vibration of the unit, the cracks will further expand and develop into a hidden danger to the safe operation of the hydropower unit. Therefore, during the temporary maintenance of the unit, it is extremely important to be able to carry out effective inspections of key metal components of small and medium-sized hydropower units in a timely manner without dismantling the unit. By accurately measuring the small cracks in each metal component, its health status can be evaluated in a timely and effective manner, which can not only detect potential hidden dangers of the unit, but also serve as a scientific basis for the selection of deep peak-shaving units.

[0004] In the actual maintenance of small and medium-sized hydropower units, the inspection and testing of important metal parts need to take into account the following factors: (1) The maintenance cycle of hydropower units is long, and the timing of health assessment is not within the planned maintenance period. It may be necessary to wait until the next maintenance period to shut down for inspection; (2) Certain important metal parts, such as the generator center body weld, runner blade weld, movable guide vane shaft diameter and other key parts, are hidden and narrow spaces, and the unit needs to be disassembled during the A-level maintenance period before effective inspection and testing can be carried out; (3) During the shutdown maintenance period, the inspection efficiency is low due to the limitation of narrow space, and the maintenance period requirements for the unit are high, which will affect the economic benefits of the hydropower station and cause economic losses to the station; (4) Due to the narrow space of important metal parts, cracks found during inspection are difficult to locate and quantify. Summary of the invention

[0005] The purpose of the embodiments of the present invention is to provide a defect detection system and a defect detection method, so as to at least solve the above-mentioned problems of long shutdown detection interval, inconvenient and low efficiency of manual maintenance operation, and difficult positioning and inaccurate quantification of cracks found during detection.

[0006] In order to achieve the above object, the present invention provides a defect detection system, which is applied to a hydropower unit, and the system comprises: an ultrasonic detection device and a server connected to the ultrasonic detection device for communication, wherein the ultrasonic detection device comprises: Carrying frame; An ultrasonic probe is arranged on a mounting mechanism, wherein the mounting mechanism is arranged on a supporting frame through a telescopic mechanism, and the ultrasonic probe is used to transmit ultrasonic waves to a detection area and receive reflected echo signals; A walking mechanism, arranged on the lower end surface of the carrier, is used to generate displacement to change the position of the ultrasonic detection device to achieve defect detection in different detection areas; A processor is arranged on the carrier and connected to the server, the ultrasonic probe and the walking mechanism. The processor controls the operation of the ultrasonic probe and the walking mechanism based on the received control instruction, and sends the echo signal to the server; The server is used to send a control instruction to the processor, and determine a defect state of a detection area based on the echo signal, wherein the defect state includes the presence of a defect and the absence of a defect.

[0007] Optionally, the system further includes: The signal relay module is communicatively connected with the processor and the server, and is used to realize data relay transmission.

[0008] Optionally, the ultrasonic detection device further includes: An encoder, arranged on the walking mechanism, for detecting the displacement of the walking mechanism, the encoder being connected to the processor; The processor is also used to send the displacement to the server; The server is also used to determine the number of the detection area based on the displacement, and store the number of the detection area after binding it with the defect status of the detection area.

[0009] Optionally, the ultrasonic detection device further includes: A camera mechanism, which is arranged on the carrier frame via a pan / tilt platform, and is used to obtain an image of the detection area, and the processor is also used to send the image of the detection area to the server; A fill light, arranged on the pan-tilt platform, for providing fill light when the camera mechanism acquires an image of the detection area; The system further comprises: The display mechanism is connected to the server and is used to display the defect status of the detection area and the image of the detection area.

[0010] Optionally, the walking mechanism includes: a wheeled magnetic adsorption movement mechanism or a tracked magnetic adsorption movement mechanism.

[0011] Optionally, an anti-collision strip is provided on the outer side wall of the supporting frame.

[0012] Optionally, the mounting mechanism includes: A mounting plate, wherein a concave mounting groove is provided on the lower surface of the mounting plate, and the ultrasonic probe is arranged in the mounting groove; A plurality of rolling mechanisms are symmetrically arranged on the lower surface of the mounting plate and located on both sides of the mounting groove, and are in rolling contact with the surface of the detection area during the detection process.

[0013] Optionally, the telescopic mechanism includes: At least one sleeve with a hollow interior is vertically arranged in the middle of the carrier; At least one sleeve rod is slidably arranged in each sleeve, the movable end of the sleeve rod located in the sleeve is connected to the sleeve through a spring, and the connecting end of the sleeve rod located outside the sleeve is rotatably connected to the installation mechanism.

[0014] On the other hand, the present invention further provides a defect detection method, which is applied to the above-mentioned defect detection system, and the method comprises: Acquire echo signal; De-noising the echo signal to obtain a de-noised echo signal; The defect status of the inspection area is determined by using the denoised echo signal.

[0015] Optionally, denoising the received echo signal to obtain a denoised echo signal includes: The echo signal is processed by using Hilbert transform to obtain transformed data; The transformed data is reconstructed using the wavelet threshold denoising algorithm to obtain the denoised echo signal; The defect status of the inspection area is determined by using the denoised echo signal, including: For each detection area: If there is a signal amplitude greater than a preset threshold in the denoised echo signal corresponding to the detection area, it is determined that there is a defect in the detection area, otherwise, it is determined that there is no defect in the detection area.

[0016] The ultrasonic detection device of this scheme has a simple structure and can detect the narrow space of the hydropower unit during the temporary shutdown and maintenance of the unit. It is easy to operate and has high detection efficiency, which reduces the labor intensity of maintenance personnel and realizes fast and accurate defect detection.

[0017] Other features and advantages of the embodiments of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings are used to provide a further understanding of the embodiments of the present invention and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the embodiments of the present invention, but do not constitute a limitation on the embodiments of the present invention. In the accompanying drawings: Figure 1 It is a structural schematic diagram of the defect detection system provided by the present invention; Figure 2 is a front view of the ultrasonic detection device provided by the present invention; Figure 3 is a top view of the ultrasonic detection device provided by the present invention; Figure 4 It is a partial structural schematic diagram of the ultrasonic detection device provided by the present invention; Figure 5 It is a structural schematic diagram of the installation mechanism provided by the present invention; Figure 6 It is a flow chart of the defect detection method provided by the present invention.

[0019] Description of Reference Numerals 100-ultrasonic detection device; 200-server; 300-signal relay module; 400-display mechanism; 1-carrying frame; 2-ultrasonic probe; 3-installation mechanism; 4-retractable mechanism; 5-travelling mechanism; 6-processor; 7-encoder; 8-camera mechanism; 9-fill light; 11-anti-collision strip; 31-mounting plate; 32- rolling mechanism; 41- sleeve; 42- sleeve rod; 43-spring; 311-mounting slot. DETAILED DESCRIPTION

[0020] The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present invention, and is not used to limit the present invention.

[0021] In the embodiments of the present invention, unless otherwise specified, directional words such as "up, down, left, right" generally refer to the directions or positional relationships shown in the accompanying drawings, or the directions or positional relationships in which the inventive product is usually placed when in use.

[0022] The terms “first”, “second”, etc. are only used for distinguishing descriptions and should not be understood as indicating or implying relative importance.

[0023] The terms "parallel", "vertical", etc. do not mean that the components must be absolutely parallel or vertical, but can be slightly tilted. For example, "parallel" only means that its direction is more parallel than "vertical", and does not mean that the structure must be completely parallel, but can be slightly tilted.

[0024] The terms "horizontal", "vertical", "overhanging" and the like do not mean that the components are required to be absolutely horizontal, vertical or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0025] In addition, the terms "roughly" and "basically" are intended to explain that the relevant content does not require absolute precision, but can have certain deviations. For example, "roughly equal" does not only mean absolute equality. Since it is difficult to achieve absolute "equality" in actual production and operation, there are generally certain deviations. Therefore, in addition to absolute equality, "roughly equal" also includes the above-mentioned situation with certain deviations. Taking this as an example, in other cases, unless otherwise specified, the terms "roughly" and "basically" have similar meanings to the above.

[0026] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0027] Figure 1 It is a structural schematic diagram of the defect detection system provided by the present invention; Figure 2 is a front view of the ultrasonic detection device provided by the present invention; Figure 3 is a top view of the ultrasonic detection device provided by the present invention; Figure 4 It is a partial structural schematic diagram of the ultrasonic detection device provided by the present invention; Figure 5 It is a structural schematic diagram of the installation mechanism provided by the present invention; Figure 6 It is a flow chart of the defect detection method provided by the present invention.

[0028] like Figure 1-3 As shown, this embodiment provides a defect detection system, which is applied to a hydropower unit. The system includes: an ultrasonic detection device 100 and a server 200 connected to the ultrasonic detection device 100 for communication. The ultrasonic detection device 100 includes: Carrying frame 1; An ultrasonic probe 2 is arranged on a mounting mechanism 3, wherein the mounting mechanism 3 is arranged on the carrier 1 through a telescopic mechanism 4, and the ultrasonic probe 2 is used to transmit ultrasonic waves to a detection area and receive reflected echo signals; A walking mechanism 5, arranged on the lower end surface of the carrier 1, is used to generate displacement to change the position of the ultrasonic detection device 100, so as to realize defect detection in different detection areas; A processor 6 is disposed on the carrier 1 and connected to the server 200, the ultrasonic probe 2 and the walking mechanism 5. The processor 6 controls the ultrasonic probe 2 and the walking mechanism 5 to work based on the received control instruction, and sends the echo signal to the server 200; The server 200 is used to send a control instruction to the processor 6, and determine the defect status of the detection area based on the echo signal, where the defect status includes the presence of a defect and the absence of a defect.

[0029] Specifically, in this embodiment, in order to realize defect detection in narrow areas, an ultrasonic detection device 100 is set, and the support frame 1 set has a certain structural strength, which can realize the bearing of other components, and the support frame 1 has an internal installation area, and the ultrasonic probe 2 is located in the internal installation area of ​​the support frame 1; secondly, the ultrasonic detection device 100 can realize displacement adjustment when the walking mechanism 5 is working, so as to perform defect detection on different detection areas. When the walking mechanism 5 works and the ultrasonic detection device 100 is moved into place, the ultrasonic probe 2 transmits ultrasonic waves to the detection area and receives the reflected echo signal, and sends the echo signal to the server 200 through the processor 6 (a wireless communication module is provided in the processor 6 to realize data transmission). The server 200 is set in the monitoring room and is used to generate control instructions of the ultrasonic probe 2 and the walking mechanism 5 according to the external input signal to realize the start and stop control of the ultrasonic probe 2 and the walking mechanism 5. Secondly, the server 200 can determine the defect state of the detection area based on the received echo signal, and the defect state includes the presence of defects and the absence of defects.

[0030] More specifically, the ultrasonic probe 2 is an ultrasonic transmitting array and an ultrasonic receiving array, which adopts an array structure and can use the phased array full focusing technology to focus the small cracks in the narrow space of the metal parts to one point through the phased array, forming a signal strength to determine the size of the crack. A micro phased array probe is used to perform quasi-defect scanning on the weld in a narrow space, focusing the sound speed on the millimeter-level area, and forming an A-scan echo signal, as well as a fan-shaped and C-shaped display image, and intelligently identifying the image. The walking mechanism 5 walks at a relatively small preset speed to achieve displacement adjustment.

[0031] Through the above scheme, the narrow space of the hydropower unit can be detected during the temporary shutdown and maintenance of the unit. It is easy to operate and has high detection efficiency, which reduces the labor intensity of maintenance personnel and realizes fast and accurate defect detection.

[0032] Furthermore, the system further comprises: The signal relay module 300 is connected to the processor 6 and the server 200 for communication and is used to implement data relay transmission.

[0033] Specifically, in this embodiment, since the outer shell of the hydropower unit is made of metal, which will cause signal shielding when defect detection is performed inside the hydropower unit, a signal relay module 300 is set at the edge of the hydropower unit during the detection process to achieve data communication connection between the ultrasonic detection device 100 in the hydropower unit and the server 200.

[0034] Furthermore, the ultrasonic detection device 100 further includes: An encoder 7, arranged on the walking mechanism 5, for detecting the displacement of the walking mechanism 5, the encoder 7 being connected to the processor 6; The processor 6 is also used to send the displacement to the server 200; The server 200 is further configured to determine the number of the detection area based on the displacement, and bind the number of the detection area with the defect status of the detection area and store them.

[0035] Specifically, in this embodiment, firstly, since the ultrasonic detection device 100 has a certain length, during the ultrasonic detection process, a certain range of areas can be detected at the same time. Therefore, the walking mechanism 5 can be controlled to move a preset length, then stop moving, and then transmit ultrasonic waves through the ultrasonic probe 2, and receive ultrasonic echo signals. Therefore, the encoder 7 is set to detect the displacement of the walking mechanism 5 to achieve control feedback and displacement detection of the walking mechanism 5. Secondly, since the total length of the hydropower unit that needs to be ultrasonically detected is known, the total length is divided into intervals with the initial position as the starting point, and multiple continuous detection areas are determined, and the detection areas are numbered. In the actual detection process, after the walking mechanism 5 is controlled to move, the displacement of the walking mechanism 5 can be detected by the encoder 7, so as to determine which detection area the current ultrasonic detection device 100 is in, so as to bind the number of the detection area with the defect state of the detection area and store it for subsequent viewing, and to perform fast and accurate regular detection on the defective area to determine its defect change.

[0036] Furthermore, if Figure 1-4 As shown, the ultrasonic detection device 100 further includes: A camera mechanism 8 is arranged on the support frame 1 via a pan / tilt platform, and is used to obtain an image of the detection area. The processor 6 is also used to send the image of the detection area to the server 200; The fill light 9 is arranged on the pan / tilt platform and is used for fill light when the camera mechanism 8 acquires the image of the detection area.

[0037] Specifically, in this embodiment, the camera mechanism 8 is capable of capturing the internal image of the hydropower unit to assist in defect judgment; in addition, in order to ensure the quality of the captured image, a fill light 9 is provided for fill light, and the fill light 9 and the camera mechanism 8 are both provided on the gimbal, thereby realizing image capture at different angles.

[0038] The system further comprises: The display mechanism 400 is connected to the server 200 and is used to display the defect status of the detection area and the image of the detection area.

[0039] Specifically, in this embodiment, the defect status of the detection area and the image of the detection area are displayed by the display mechanism 400, so that the detection result can be presented intuitively.

[0040] In another embodiment, the system further includes: an alarm, connected to the server 200, for generating an alarm when it is determined that the defect state of the detection area is defective, so as to provide a timely reminder.

[0041] Furthermore, the walking mechanism 5 includes: a wheeled magnetic attraction movement mechanism or a tracked magnetic attraction movement mechanism.

[0042] Specifically, in this embodiment, in order to increase the application scope of the ultrasonic detection device 100, the walking mechanism 5 is configured to include a wheeled magnetic adsorption motion mechanism or a tracked magnetic adsorption motion mechanism, so as to realize defect detection on the side or top surface through magnetic adsorption force.

[0043] Furthermore, an anti-collision strip 11 is provided on the outer side wall of the carrier frame 1 .

[0044] Specifically, in this embodiment, an anti-collision strip 11 is provided on the outer wall of the carrier frame 1 to reduce the collision force; the anti-collision strip 11 can be set to a rubber material with a certain elasticity. Secondly, in order to guide the carrier frame 1 when a collision occurs and avoid getting stuck, the anti-collision strip 11 is set to a waist-shaped hole structure, and the carrier frame 1 is wrapped inside.

[0045] Furthermore, if Figure 5 As shown, the mounting mechanism 3 comprises: A mounting plate 31, wherein a concave mounting groove 311 is provided on the lower surface of the mounting plate 31, and the ultrasonic probe 2 is arranged in the mounting groove 311; A plurality of rolling mechanisms 32 are symmetrically arranged on the lower surface of the mounting plate 31 and located on both sides of the mounting groove 311 , and are in rolling contact with the surface of the detection area during the detection process.

[0046] Specifically, in this embodiment, a concave mounting groove 311 is provided on the lower surface of the mounting plate 31, and the ultrasonic probe 2 is disposed in the mounting groove 311 to protect the ultrasonic probe 2. In addition, in order to reduce the friction between the mounting plate 31 and the surface of the detection area of ​​the hydropower unit during the movement of the ultrasonic detection device 100, a plurality of rolling mechanisms 32 are symmetrically provided on the lower surface of the mounting plate 31 to reduce friction by rolling.

[0047] More specifically, the rolling mechanism 32 can be configured as a structure such as a roller, a ball, or a roller bar.

[0048] Furthermore, if Figure 5 As shown, the telescopic mechanism 4 includes: At least one hollow sleeve 41 is vertically arranged in the middle of the carrier 1; At least one sleeve rod 42 is slidably disposed in each sleeve 41 , the movable end of the sleeve rod 42 located in the sleeve 41 is connected to the sleeve 41 through a spring 43 , and the connecting end of the sleeve rod 42 located outside the sleeve 41 is rotatably connected to the mounting mechanism 3 .

[0049] Specifically, in the present embodiment, since it is necessary to ensure that the interval between the ultrasonic probe 2 and the detection area is small when ultrasonic waves are emitted by the ultrasonic probe 2 for defect detection, a telescopic mechanism 4 is provided, a sleeve 41 is on the carrier frame 1, and a sleeve rod 42 is slidably provided in each sleeve 41, and the movable end of the sleeve rod 42 located in the sleeve 41 is connected to the sleeve 41 through a spring 43, and a downward thrust is generated by the spring to keep the distance between the installation mechanism 3 and the detection area constant; in addition, since the detection area may be tilted at a small angle, in order to increase the scope of application, the connecting end of the sleeve rod 42 located outside the sleeve 41 is rotatably connected to the installation mechanism 3, so as to realize the angle deflection of the installation mechanism 3 and achieve a close fit.

[0050] More specifically, the connecting end of the sleeve rod 42 outside the sleeve 41 is rotatably connected to the mounting mechanism 3 via a ball bearing, thereby achieving deflection at different angles so that it can better fit the surface of the detection area during actual use.

[0051] The embodiment of the present invention further provides a defect detection method, which is applied to the above-mentioned defect detection system, such as Figure 6 As shown, the method includes: Acquire echo signal; De-noising the echo signal to obtain a de-noised echo signal; The defect status of the inspection area is determined by using the denoised echo signal.

[0052] Specifically, in the process of ultrasonic detection using ultrasonic instruments, different types of interference waves exist in the echo, causing the ultrasonic signal to be interfered by noise, making it impossible to obtain accurate ultrasonic waveforms, which is not conducive to signal analysis and subsequent processing. Therefore, it is of great application value to seek a reasonable method to implement denoising operations on the detected ultrasonic signal. Ultrasonic signals are dynamic time-varying pulse signals, and the signal spectrum characteristics extend along the time axis. In the process of ultrasonic signal denoising by Fourier transform in the traditional method, the time-varying characteristics of ultrasonic signals cannot be solved, and the denoising effect is not ideal. Therefore, in this embodiment, the received echo signal is denoised to obtain a denoised echo signal, including: using Hilbert transform to process the echo signal to obtain transformed data; using wavelet threshold denoising algorithm to reconstruct the transformed data to obtain a denoised echo signal. First, the Hilbert transform can complete the orthogonal phase shift of the signal and improve the accuracy of the signal; in addition, the wavelet threshold denoising algorithm reconstructs the transformed data, which can improve the denoising accuracy and ensure the accuracy of the result.

[0053] Furthermore, the defect status of the detection area is determined by using the denoised echo signal, including: For each detection area: If the signal amplitude in the denoised echo signal corresponding to the detection area is greater than a preset threshold, it is determined that the detection area has a defect; otherwise, it is determined that the detection area does not have a defect.

[0054] Specifically, in this embodiment, when there is a defect in a steel workpiece, due to the existence of this defect, an interface between different media is formed between the defect and the steel material. The acoustic impedance between the interfaces is different. When the emitted ultrasonic wave encounters this interface, it will be reflected, and the reflected energy will be received by the probe again. Therefore, when there is a signal amplitude greater than the preset threshold in the denoised echo signal corresponding to the detection area, it means that there is an abnormal signal, and it can be determined that there is a defect in the detection area. Otherwise, it is determined that there is no defect in the detection area.

[0055] Those skilled in the art will understand that all or part of the steps in the method for implementing the above-mentioned embodiments can be completed by instructing the relevant hardware through a program, and the program is stored in a storage medium, including several instructions for making a single-chip microcomputer, a chip or a processor execute all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0056] The optional embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the embodiments of the present invention are not limited to the specific details in the above embodiments. Within the technical concept of the embodiments of the present invention, the technical scheme of the embodiments of the present invention can be subjected to a variety of simple modifications, and these simple modifications all belong to the protection scope of the embodiments of the present invention. It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the embodiments of the present invention will not further describe various possible combinations.

[0057] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the embodiments of the present invention, they should also be regarded as the contents disclosed in the embodiments of the present invention.

Claims

1. A defect detection system, applied to a hydropower unit, characterized in that: The system comprises: an ultrasonic detection device (100) and a server (200) connected in communication with the ultrasonic detection device (100), wherein the ultrasonic detection device (100) comprises: A carrier frame (1); An ultrasonic probe (2) is arranged on a mounting mechanism (3), wherein the mounting mechanism (3) is arranged on the support frame (1) via a telescopic mechanism (4), and the ultrasonic probe (2) is used to transmit ultrasonic waves to a detection area and receive reflected echo signals; A walking mechanism (5) is arranged on the lower end surface of the carrier (1) and is used to generate displacement to change the position of the ultrasonic detection device (100) to achieve defect detection in different detection areas; a processor (6), arranged on the carrier (1), connected to the server (200), the ultrasonic probe (2) and the walking mechanism (5), wherein the processor (6) controls the operation of the ultrasonic probe (2) and the walking mechanism (5) based on received control instructions, and sends the echo signal to the server (200); The server (200) is used to send a control instruction to the processor (6), and determine the defect status of the detection area based on the echo signal, wherein the defect status includes the presence of a defect and the absence of a defect.

2. The defect detection system according to claim 1, characterized in that: The system further comprises: The signal relay module (300) is communicatively connected with the processor (6) and the server (200) and is used to implement data relay transmission.

3. The defect detection system according to claim 1, characterized in that: The ultrasonic detection device (100) further comprises: An encoder (7) is arranged on the walking mechanism (5) and is used to detect the displacement of the walking mechanism (5), and the encoder (7) is connected to the processor (6); The processor (6) is further configured to send the displacement to a server (200); The server (200) is further used to determine the number of the detection area based on the displacement, and to bind the number of the detection area with the defect state of the detection area and store them.

4. The defect detection system according to claim 1, characterized in that: The ultrasonic detection device (100) further comprises: A camera mechanism (8) is arranged on the carrier frame (1) via a pan / tilt platform and is used to obtain an image of the detection area; the processor (6) is also used to send the image of the detection area to the server (200); A fill light (9) is arranged on the pan-tilt platform and is used to provide fill light when the camera mechanism (8) acquires an image of the detection area; The system further comprises: The display mechanism (400) is connected to the server (200) and is used to display the defect status of the detection area and the image of the detection area.

5. The defect detection system according to claim 1, characterized in that: The walking mechanism (5) comprises: a wheeled magnetic attraction movement mechanism or a tracked magnetic attraction movement mechanism.

6. The defect detection system according to claim 1, characterized in that: An anti-collision strip (11) is provided on the outer side wall of the carrier frame (1).

7. The defect detection system according to claim 1, characterized in that: The mounting mechanism (3) comprises: A mounting plate (31), wherein a lower surface of the mounting plate (31) is provided with a concave mounting groove (311), and the ultrasonic probe (2) is arranged in the mounting groove (311); A plurality of rolling mechanisms (32) are symmetrically arranged on the lower surface of the mounting plate (31) and are located on both sides of the mounting groove (311), and are in rolling contact with the surface of the detection area during the detection process.

8. The defect detection system according to claim 1, characterized in that: The telescopic mechanism (4) comprises: At least one hollow sleeve (41) disposed vertically in the middle of the support frame (1); At least one sleeve rod (42), one sleeve rod (42) being slidably disposed in each sleeve (41), the movable end of the sleeve rod (42) located in the sleeve (41) being connected to the sleeve (41) via a spring (43), and the connecting end of the sleeve rod (42) located outside the sleeve (41) being rotatably connected to the mounting mechanism (3).

9. A defect detection method, applied to the defect detection system according to any one of claims 1 to 8, characterized in that: The method comprises: Acquire echo signal; De-noising the echo signal to obtain a de-noised echo signal; The defect status of the inspection area is determined by using the denoised echo signal.

10. The defect detection method according to claim 9, characterized in that: De-noising the received echo signal to obtain a de-noised echo signal, including: The echo signal is processed by using Hilbert transform to obtain transformed data; The transformed data is reconstructed using the wavelet threshold denoising algorithm to obtain the denoised echo signal; The defect status of the inspection area is determined by using the denoised echo signal, including: For each detection area: If there is a signal amplitude greater than a preset threshold in the denoised echo signal corresponding to the detection area, it is determined that there is a defect in the detection area, otherwise, it is determined that there is no defect in the detection area.

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