A TOFD inspection system for small diameter thick wall pipes

Abstract

The invention relates to the technical field of ultrasonic analysis, and specifically discloses a TOFD detection system for small-diameter thick-walled pipes, which is used to solve the problem that when performing TOFD detection on small-diameter thick-walled pipes, a scanning frame cannot fit the outer wall of the pipe, and the coupling between the probe and the pipe wall is unstable, resulting in a large sensitivity difference during the scanning process; the invention ensures that the first probe can be automatically adjusted according to the curvature of the pipe surface through a first adaptive probe bracket, dynamically adjusts the probe position based on a second adaptive probe bracket, ensures that the second probe can be automatically adjusted according to the curvature of the pipe surface, uses a first dynamic adjustment module to detect the diameter and curvature of the pipe, increases or decreases the number of chain link units in real time, and dynamically adjusts the working coefficients between the first adaptive probe bracket and the second adaptive probe bracket and the pipe based on a second dynamic adjustment module; the invention can improve detection accuracy and detection efficiency, and enhance the adaptability and flexibility of the system.

Description

Technical Field

[0001] The present invention relates to the technical field of ultrasonic analysis, and more particularly to a TOFD detection system for small-diameter thick-walled pipes. Background Art

[0002] TOFD (Time-of-Flight Diffraction) is commonly used for the inspection of pressure vessels and large-diameter annular seams and longitudinal seams. The sending probe emits ultrasonic signals. When the ultrasonic wave encounters a defect (such as a crack, a cavity, etc.), the ultrasonic wave will diffract at the edge of the defect, and the receiving probe will receive these diffraction signals. Because its conventional scanning frame is flat and large in size, for small-diameter pipe inspection, the scanning frame cannot fit the outer wall of the pipe. At the same time, the coupling between the probe and the pipe wall is unstable, which will cause a large difference in sensitivity during the scanning process, greatly affecting the detection rate of defects.

[0003] For example, a single-side TOFD detection method for welds is disclosed in a Chinese patent application with publication number CN110988132A, wherein the weld detection system has a first transmitting probe and a first receiving probe, and the method includes: the first transmitting probe is arranged on the target detection part and is located on one side of the target weld, and the first receiving probe is arranged on the target detection part and is located on the same side of the target weld as the first transmitting probe; the first transmitting probe transmits ultrasonic waves, the first receiving probe receives ultrasonic waves, and the distance between the first receiving probe and the first transmitting probe is adjusted to make the received signal strength the strongest; and whether the target weld has defects is determined based on the ultrasonic emission intensity distribution of the first transmitting probe and the signal intensity distribution received by the first receiving probe. When using the present invention, it is not necessary to consider the irregular interface connected to the pipeline and the parts at the other end of the interface, and the weld detection at the pipeline and flange interface or the irregular pipeline interface can be completed.

[0004] The above patents all have the problems raised by this background technology: when performing TOFD inspection on small-diameter thick-walled pipes, the scanning frame cannot fit the outer wall of the pipe, and the coupling between the probe and the pipe wall is unstable, which will cause a large difference in sensitivity during the scanning process, greatly affecting the detection rate of defects, resulting in the obstruction of ultrasonic wave propagation between the probe and the pipe wall, which directly affects the accuracy of the detection results. Summary of the invention

[0005] In order to overcome the above-mentioned defects of the prior art, the present invention provides a TOFD detection system for small-diameter thick-walled pipes, which is used to solve the problem that when performing TOFD detection on small-diameter thick-walled pipes, the scanning frame cannot fit the outer wall of the pipe, and the coupling between the probe and the pipe wall is unstable, resulting in a large difference in sensitivity during the scanning process, so as to solve the problems raised in the above-mentioned background technology.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A TOFD detection system for small-diameter thick-walled pipes includes a chain scanning frame, a first probe, a first adaptive probe bracket, a second probe, a second adaptive probe bracket, a first dynamic adjustment module, a second dynamic adjustment module, and a processor, wherein the first probe is used to emit ultrasonic waves into the pipe material; the first adaptive probe bracket is used to fix the first probe and ensure that the first probe can be automatically adjusted according to the curvature of the pipe surface; the first dynamic adjustment module is used to increase or decrease the number of chain link units in real time by detecting the diameter and curvature of the pipe: by obtaining the first geometric parameters of the pipe and the second geometric parameters of the chain, the first geometric parameters include the outer diameter, curvature and thickness of the pipe, and the second geometric parameters include the length of the chain link unit and the distance between the chain link units; the formula for calculating the central angle of each chain link unit based on the first geometric parameters and the second geometric parameters is:

[0008] ;

[0009] Where: is the central angle of the i-th chain link unit, is the length of the chain unit, is the outer diameter of the pipe;

[0010] According to the obtained center angle of the chain link unit, a dynamic adjustment strategy for the chain link unit is formulated to analyze the optimal combination of the number and length of the chain link unit. The objective function of the dynamic adjustment strategy for the chain link unit is:

[0011] ;

[0012] Where: To minimize the number of chain elements , To minimize, is the number of chain link units, is the chain coverage angle, is the central angle of the i-th chain link unit, is the length of the chain unit, is the outer diameter of the pipe.

[0013] As a further solution of the present invention, the following constraints are formulated based on the objective function of the dynamic adjustment strategy of the link unit:

[0014] The length L of the link unit and the spacing d between the link units must meet the requirements of the pipe curvature. The formula is: ;

[0015] Total length of link unit The circumference of the pipe needs to be covered, and the formula is: ;

[0016] The spacing d between the chain link units must not affect the contact between the probe and the pipe surface. The formula is: .

[0017] As a further solution of the present invention, the second dynamic adjustment module is used to dynamically adjust the first working coefficient between the first adaptive probe bracket and the second adaptive probe bracket and the pipeline; the first working coefficient includes the adjustment force of the second probe height and the contact pressure between the first probe or the second probe and the pipe wall; based on the second probe obtaining the reflected signal or diffraction signal of the ultrasonic wave, the received signal strength is monitored in real time. If the signal strength is lower than the preset target signal strength threshold, the contact between the second probe and the pipe wall is poor or the coupling agent is insufficient. At this time, the second adaptive probe bracket adjusts the height based on the first adjustment feedback mechanism. The formula of the first adjustment feedback mechanism is:

[0018] ;

[0019] Where: To adjust the height of the second probe, is the feedback control coefficient, is the preset target signal strength threshold, is the actual received signal strength.

[0020] As a further solution of the present invention, the contact pressures between the first probe and the second probe and the pipe wall are respectively monitored in real time by pressure sensors installed on the first adaptive probe holder and the second adaptive probe holder. The contact pressures between the first probe and the second probe and the pipe wall are respectively monitored during ultrasonic propagation, and a second adjustment feedback mechanism is formulated to adjust the contact pressure. The formula of the second adjustment feedback mechanism is:

[0021] ;

[0022] Where: To adjust the contact pressure between the first probe or the second probe and the pipe wall, is the feedback control coefficient, To preset the target contact pressure value between the first probe or the second probe and the pipe wall, is the contact pressure value between the first probe or the second probe and the pipe wall.

[0023] An electronic device comprises: a memory storing executable program codes; a processor coupled to the memory; the processor calls the executable program codes stored in the memory to execute the TOFD detection system for small-diameter thick-walled pipes.

[0024] A computer storage medium stores a computer program, which, when run by a processor, executes the TOFD detection system for small-diameter thick-walled pipes.

[0025] A computer program product comprises a computer program, wherein the computer program is executed by a processor to execute the TOFD detection system for small-diameter thick-walled pipes.

[0026] The technical effects and advantages of a TOFD detection system for a small-diameter thick-walled pipe of the present invention are as follows: the present invention ensures that the first probe can be automatically adjusted according to the curvature of the pipe surface through a first adaptive probe holder, dynamically adjusts the probe position based on a second adaptive probe holder, ensures that the second probe can be automatically adjusted according to the curvature of the pipe surface, utilizes a first dynamic adjustment module to detect the diameter and curvature of the pipe, increases or decreases the number of chain link units in real time, and avoids detection failure or signal weakening caused by the scanning frame being unable to be close to the pipe; and based on the second dynamic adjustment module, is used to dynamically adjust the working coefficient between the first adaptive probe holder and the second adaptive probe holder and the pipe, the pressure and position of the probe holder can be automatically adjusted according to the detection requirements of different pipe surfaces, and the sensitivity consistency during the detection process is maintained; through the adaptive adjustment and real-time monitoring of the probe holder, the sensitivity of the probe at different positions is ensured to be consistent, the fluctuation of the signal is reduced, and the improvement of the defect detection rate is guaranteed, especially for the detection of tiny defects. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A schematic structural diagram of a TOFD detection system for small-diameter thick-walled pipes provided by the present invention.

[0028] Figure 2 This is a schematic diagram of the structure of the contact between the probe adaptive bracket and the pipeline in the TOFD detection system for small-diameter thick-walled pipes.

[0029] In the figure: 1. chain link unit; 2. second probe; 3. connecting component; 4. second adaptive probe bracket; 5. probe fixing fixture; 6. first probe; 7. first adaptive probe bracket; 8. pipeline. DETAILED DESCRIPTION

[0030] The following will be combined with the accompanying drawings in the present invention to clearly and completely describe the technical solution in the present invention. Obviously, the described technical solution is only a part of the present invention, not all of it. Based on the technical solution in the present invention, all other technical solutions obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0031] Figure 1 FIG. 2 shows a schematic diagram of a TOFD detection system for a small diameter thick wall pipe provided by the present invention. Figure 1As shown, a TOFD detection system for small-diameter thick-walled pipes in this embodiment includes a chain scanning frame, a first probe 6, a first adaptive probe bracket 7, a second probe 2, a second adaptive probe bracket 4, a first dynamic adjustment module, a second dynamic adjustment module and a processor;

[0032] The chain scanning frame is connected to the first probe 6 and the second probe 2 respectively, the first probe 6 is connected to the first adaptive probe holder 7, the second probe 2 is connected to the second adaptive probe holder 4, the first dynamic adjustment module is connected to the first adaptive probe holder 7 through the processor communication, and the second dynamic adjustment module is connected to the second adaptive probe holder 4 through the processor communication;

[0033] The chain scanning frame is used to support the probe to adapt to the TOFD detection of pipeline surfaces with different diameters and curvatures;

[0034] The first probe 6 is used to transmit ultrasonic waves into the material of the pipe 8;

[0035] The first adaptive probe bracket 7 is used to fix the first probe 6 and ensure that the first probe 6 can be automatically adjusted according to the curvature of the surface of the pipeline 8;

[0036] The second probe 2 is used to receive ultrasonic signals reflected or diffracted from defects or the bottom of the pipe wall;

[0037] The second adaptive probe support 4 is used to support the second probe 2 and dynamically adjust the probe position to ensure that the second probe 2 can be automatically adjusted according to the curvature of the surface of the pipeline 8;

[0038] The first dynamic adjustment module is used to increase or decrease the number of chain link units 1 in real time by detecting the diameter and curvature of the pipe 8;

[0039] The second dynamic adjustment module is used to dynamically adjust the working coefficient between the first adaptive probe bracket 7 and the second adaptive probe bracket 4 and the pipeline 8;

[0040] Specifically, the chain scanning frame includes a plurality of chain link units 1 , a connecting component 3 and a probe fixing fixture 5 .

[0041] The chain link units 1 are interconnected by connecting parts 3, and the connecting parts 3 are usually joint connections, so that the chain link units 1 can be flexibly rotated and bent to adapt to different pipe diameters and curvatures of the surface of the pipe 8, so that the entire chain can adaptively adjust the angle and shape according to the surface of the pipe 8 to ensure that the probe always maintains close contact with the surface of the pipe 8; the probe fixing fixture 5 is usually installed on the chain link unit 1 to fix the probe. The probe fixing fixture 5 can be flexibly connected to the chain link unit 1 to ensure that the probe can adjust its position and angle according to the detection requirements.

[0042] The first dynamic adjustment module is used to increase or decrease the number of chain link units 1 in real time by detecting the diameter and curvature of the pipe 8: by obtaining the first geometric parameter of the pipe 8 and the second geometric parameter of the chain, the first geometric parameter includes the outer diameter, curvature and thickness of the pipe 8, and the second geometric parameter includes the length of the chain link unit 1 and the distance between the chain link units 1; the formula for calculating the central angle of each chain link unit 1 based on the first geometric parameter and the second geometric parameter is:

[0043] ;

[0044] Where: is the central angle of the i-th link unit 1, is the length of link unit 1, is the outer diameter of the pipe 8;

[0045] According to the obtained central angle of the link unit 1, a dynamic adjustment strategy for the link unit 1 is formulated to analyze the optimal combination of the number and length of the link unit 1. The objective function of the dynamic adjustment strategy for the link unit 1 is:

[0046] ;

[0047] Where: To minimize the number of chain link units 1 , To minimize, is the number of chain link units 1, is the chain coverage angle, is the central angle of the i-th link unit 1, is the length of link unit 1, is the outer diameter of the pipe 8.

[0048] The following constraints are formulated based on the objective function of the dynamic adjustment strategy of link unit 1:

[0049] The length L of the link unit 1 and the spacing d between the link units 1 must meet the curvature requirements of the pipe 8, and the formula is: ;

[0050] Total length of link unit 1 A certain circumference length of the pipe 8 needs to be covered, and the formula is: ;

[0051] The spacing d between the chain link units 1 must not affect the contact between the probe and the surface of the pipe 8, and the formula is: .

[0052] By acquiring the geometric parameters of the pipe 8 (such as outer diameter, curvature, and thickness) in real time, the system can automatically adjust the number and length of the link units 1 based on this information, so that the system can adapt to pipes 8 of various sizes and shapes, thereby expanding the application range of the equipment, especially for scenarios with complex curvature changes; the spacing between the link units 1 is limited to ensure that the probe always maintains good contact with the surface of the pipe 8. This helps to improve the stability and detection accuracy of the sensor signal and reduce signal distortion or errors caused by poor contact; the number of link units 1 is optimized, which means that the chain system can use the minimum number of link units 1 while ensuring effective coverage of the pipeline 8, thereby reducing material and manufacturing costs and reducing the complexity of the system; ensuring that the total length of the chain is sufficient to cover the area of ​​the pipeline 8 that needs to be inspected, preventing the occurrence of detection blind spots, and making the system more reliable and comprehensive when performing detection tasks; by adjusting the length and number of link units 1 in real time, it can quickly adapt to changes in different pipelines 8, reducing debugging and manual adjustment time, and improving detection efficiency, especially in the detection environment of multiple pipelines 8 or pipelines 8 of different diameters; by automatically adjusting the number, length and spacing of link units 1, it can optimize the contact quality between the probe and the pipeline 8, improve the sensitivity and accuracy of detection, reduce mechanical losses, and minimize the number of links to save costs and space, thereby enhancing the flexibility and automation level of the equipment and greatly improving the operating efficiency and service life of the equipment.

[0053] Specifically, the second dynamic adjustment module is used to dynamically adjust the working coefficient between the first adaptive probe holder 7 and the second adaptive probe holder 4 and the pipe 8: based on the acoustic wave equation model, the propagation process of ultrasonic waves in the thick-walled pipe 8 is simulated. The formula of the acoustic wave equation model is:

[0054] ;

[0055] Where: is the sound pressure, is the gradient operator, is the Laplace operator of the sound pressure p, is the propagation speed of sound waves in the medium, For time, is the second-order derivative of the sound pressure p with time, is the relationship between the temporal variation of sound pressure and the speed of sound c;

[0056] The second probe 2 acquires the reflected signal or diffracted signal of the ultrasonic wave and monitors the received signal strength in real time. If the signal strength is lower than the preset target signal strength threshold, the contact between the probe and the pipe wall is poor or the coupling agent is insufficient. At this time, the second adaptive probe bracket 4 adjusts the height based on the first adjustment feedback mechanism. The formula of the first adjustment feedback mechanism is:

[0057] ;

[0058] Where: To adjust the height of the second probe 2, is the feedback control coefficient, is the preset target signal strength threshold, is the actual received signal strength.

[0059] The contact pressures between the first probe 6 and the second probe 2 and the pipe wall are respectively monitored in real time by the pressure sensors installed on the first adaptive probe holder 7 and the second adaptive probe holder 4. The contact pressures between the first probe 6 and the second probe 2 and the pipe wall are respectively monitored in real time. The contact pressures are adjusted by formulating a second adjustment feedback mechanism by monitoring the contact pressures between the first probe 6 and the second probe 2 and the pipe wall during ultrasonic propagation. The formula of the second adjustment feedback mechanism is:

[0060] ;

[0061] Where: To adjust the contact pressure between the first probe 6 or the second probe 2 and the pipe wall, is the feedback control coefficient, To preset the target contact pressure value between the first probe 6 or the second probe 2 and the pipe wall, is the contact pressure value between the first probe 6 or the second probe 2 and the pipe wall.

[0062] The first adjustment feedback mechanism adjusts the height of the probe by monitoring the strength of the ultrasonic signal received by the second probe 2 to ensure that the probe maintains the best coupling state with the pipe wall: the second probe 2 monitors the signal strength reflected or diffracted by the ultrasonic wave in real time, and the change in signal strength directly reflects the contact state between the probe and the pipe wall. If the signal strength is lower than the preset target threshold, it means that the probe is in poor contact with the pipe wall or the coupling agent is insufficient; if the signal strength is normal or higher than the threshold, the probe is in good contact with the pipe wall and no further adjustment is required. When the signal strength is lower than the target threshold, the first adjustment feedback mechanism is activated to calculate the adjustment force. According to the calculated adjustment force, the height of the probe bracket is adjusted by a spring, a pneumatic cylinder or an electric drive to increase or decrease the contact distance with the pipe wall until the received signal strength returns to the target threshold. When the diameter of the pipe 8 increases, the number of chain link units 1 needs to be increased to ensure that the probe can cover a larger range; when the diameter decreases, the number of chain link units 1 is reduced to ensure that the probe can be close to the pipe wall; according to the curvature of the pipe 8, the angle between the chain links of the bracket can be automatically adjusted to ensure that each probe module can be evenly distributed along the curved surface of the pipe wall to avoid irregular contact.

[0063] Each probe holder has a certain multi-degree-of-freedom adjustment function (including height, angle, contact pressure), which can ensure that the probe can be adaptively adjusted according to the surface irregularities of the pipeline 8 (such as welds, bends, surface roughness); the distance between the probe and the pipe wall is adjusted through feedback to ensure that the ultrasonic signal strength is within the preset range; the probe holder can adaptively adjust the emission angle of the probe according to the slope or curvature of the pipe wall surface to ensure the best reflection and diffraction effect of the signal; the probe holder automatically adjusts the contact force according to the actual measured contact pressure to avoid poor coupling due to too little pressure or signal distortion due to excessive pressure.

[0064] The second adjustment feedback mechanism is used to dynamically adjust the contact pressure of the probe to ensure that the probe maintains the best contact force with the pipe wall under different surface conditions, avoiding signal distortion or poor coupling caused by excessive or insufficient pressure. Through the pressure sensor, the system monitors the contact pressure between the probe and the pipe wall in real time. If the probe contact pressure is lower than the target pressure, it means that the probe is in too loose contact with the pipe wall, which may cause poor coupling; if the contact pressure is higher than the target pressure, it means that the probe is in too tight contact with the pipe wall, which may cause signal distortion or mechanical damage. When the contact pressure deviates from the target pressure, the second adjustment feedback mechanism is activated, the adjustment pressure is calculated, and the pressure of the probe bracket is adjusted according to the feedback. The specific steps are: calculate the pressure difference to be adjusted, increase or decrease the contact pressure on the bracket through the air pressure system, spring or other driving mechanism until the pressure returns to the preset target value.

[0065] The first adaptive probe holder 7 and the second adaptive probe holder 4 form a closed-loop control system through real-time monitoring of signal strength and contact pressure, ensuring that the probe always maintains the best working state during the entire detection process; by real-time monitoring of the ultrasonic signal strength and contact pressure received by the second probe 2, if the signal strength or contact pressure deviates from the preset value, the system calculates the adjustment force and adjustment pressure according to the feedback mechanism, and adjusts the probe height and pressure in real time; the first adaptive probe holder 7 and the second adaptive probe holder 4 automatically adjust the probe height, angle and pressure according to signal feedback, ensuring the strength and stability of the ultrasonic signal during the detection process.

[0066] The overall dynamic adjustment process of the first adaptive probe bracket 7 and the second adaptive probe bracket 4 relies on the feedback mechanism of real-time signal strength and contact pressure. Through the adaptive adjustment of height, angle and pressure, it ensures that the probe can fit closely to the pipe wall during the entire detection process to maintain the best ultrasonic coupling and signal transmission quality. Through the dynamic adjustment module and the adaptive adjustment bracket, the system can automatically adapt to the changes in the diameter and curvature of the pipe 8, further improving the detection accuracy and stability.

[0067] An electronic device comprises: a memory storing executable program codes; a processor coupled to the memory; the processor calls the executable program codes stored in the memory to execute the TOFD detection system for small-diameter thick-walled pipes.

[0068] A computer storage medium stores a computer program, which, when run by a processor, executes the TOFD detection system for small-diameter thick-walled pipes.

[0069] A computer program product comprises a computer program, wherein the computer program is executed by a processor to execute the TOFD detection system for small-diameter thick-walled pipes.

[0070] Various implementations of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on chips (SOCs), complex programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various implementations can include: being implemented in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which can be a special purpose or general purpose programmable processor that can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit data and instructions to the storage system, the at least one input device, and the at least one output device.

[0071] The program code for implementing the method of the present disclosure may be written in any combination of one or more programming languages. These program codes may be provided to a processor or controller of a general-purpose computer, a special-purpose computer, or other programmable load balancing device, so that when the program code is executed by the processor or controller, the functions / operations specified in the flow chart and / or block diagram are implemented. The program code may be executed entirely on the machine, partially on the machine, partially on the machine and partially on a remote machine as a stand-alone software package, or entirely on a remote machine or server.

[0072] In the context of the present disclosure, a machine-readable medium may be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, device, or equipment. A machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or equipment, or any suitable combination of the foregoing. A more specific example of a machine-readable storage medium may include an electrical connection based on one or more lines, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0073] The systems and techniques described herein may be implemented in a computing system that includes back-end components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes front-end components (e.g., a user computer with a graphical user interface or a web browser through which a user can interact with implementations of the systems and techniques described herein), or a computing system that includes any combination of such back-end components, middleware components, or front-end components. The components of the system may be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: a local area network (LAN), a wide area network (WAN), and the Internet.

[0074] The embodiment of the present invention ensures that the first probe 6 can be automatically adjusted according to the curvature of the surface of the pipe 8 through the first adaptive probe bracket 7, and dynamically adjusts the probe position based on the second adaptive probe bracket 4 to ensure that the second probe 2 can be automatically adjusted according to the curvature of the surface of the pipe 8. The diameter and curvature of the pipe 8 are detected by the first dynamic adjustment module, and the number of chain link units 1 is increased or decreased in real time to avoid detection failure or signal weakening caused by the inability of the scanning frame to fit closely to the pipe 8; and based on the second dynamic adjustment module, it is used to dynamically adjust the working coefficient between the first adaptive probe bracket 7 and the second adaptive probe bracket 4 and the pipe 8, and the pressure and position of the probe bracket can be automatically adjusted according to the detection requirements of different surfaces of the pipe 8 to maintain the consistency of sensitivity during the detection process; through the adaptive adjustment and real-time monitoring of the probe bracket, the sensitivity of the probe at different positions is ensured to remain consistent, the signal fluctuation is reduced, and the defect detection rate is improved, especially for the detection of tiny defects.

[0075] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

[0076] Finally: The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A TOFD detection system for a small-diameter thick-walled pipe, comprising a chain scanning frame, a first probe (6), a first adaptive probe bracket (7), a second probe (2), a second adaptive probe bracket (4), a first dynamic adjustment module, a second dynamic adjustment module and a processor, characterized in that: The first probe (6) is used to transmit ultrasonic waves into the material of the pipe (8); the first adaptive probe bracket (7) is used to fix the first probe (6) and ensure that the first probe (6) can be automatically adjusted according to the curvature of the surface of the pipe (8); the first dynamic adjustment module is used to increase or decrease the number of chain link units (1) in real time by detecting the diameter and curvature of the pipe (8): by obtaining the first geometric parameter of the pipe (8) and the second geometric parameter of the chain, the first geometric parameter including the outer diameter, curvature and thickness of the pipe (8), and the second geometric parameter including the length of the chain link unit (1) and the distance between the chain link units (1); the formula for calculating the central angle of each chain link unit (1) based on the first geometric parameter and the second geometric parameter is: ； Where: is the central angle of the i-th chain link unit (1), is the length of the chain link unit (1), is the outer diameter of the pipe (8); According to the obtained central angle of the chain link unit (1), a dynamic adjustment strategy of the chain link unit (1) is formulated to analyze the optimal combination of the number and length of the chain link unit (1). The objective function of the dynamic adjustment strategy of the chain link unit (1) is: ； Where: To minimize the number of chain elements (1) , To minimize, is the number of chain link units (1), is the chain coverage angle, is the central angle of the i-th chain link unit (1), is the length of the chain link unit (1), is the outer diameter of the pipe (8); The second dynamic adjustment module is used to dynamically adjust the first working coefficient between the first adaptive probe bracket (7) and the second adaptive probe bracket (4) and the pipe (8); the first working coefficient includes the adjustment force of the height of the second probe (2) and the contact pressure between the first probe (6) or the second probe (2) and the pipe wall; based on the second probe (2) obtaining the reflected signal or diffracted signal of the ultrasonic wave, the received signal strength is monitored in real time. If the signal strength is lower than a preset target signal strength threshold, the contact between the second probe (2) and the pipe wall is poor or the coupling agent is insufficient. At this time, the second adaptive probe bracket (4) adjusts the height based on the first adjustment feedback mechanism. The formula of the first adjustment feedback mechanism is: ； Where: To adjust the height of the second probe (2), is the feedback control coefficient, is the preset target signal strength threshold, is the actual received signal strength; The contact pressures between the first probe (6) and the second probe (2) and the pipe wall are respectively monitored in real time by pressure sensors installed on the first adaptive probe bracket (7) and the second adaptive probe bracket (4). The contact pressures between the first probe (6) and the second probe (2) and the pipe wall during ultrasonic wave propagation are monitored, and a second adjustment feedback mechanism is formulated to adjust the contact pressure. The formula of the second adjustment feedback mechanism is: ； Where: To adjust the contact pressure between the first probe (6) or the second probe (2) and the pipe wall, is the feedback control coefficient, To preset a target contact pressure value between the first probe (6) or the second probe (2) and the pipe wall, is the contact pressure value between the first probe (6) or the second probe (2) and the pipe wall.

2. A TOFD detection system for small diameter thick wall pipes according to claim 1, characterized in that: The following constraints are formulated based on the objective function of the dynamic adjustment strategy of the link unit (1): The length L of the chain link unit (1) and the spacing d between the chain link units (1) must meet the curvature requirements of the pipe (8), and the formula is: ; Overall length of link unit (1) The circumference of the pipe (8) needs to be covered, and the formula is: ; The spacing d between the chain link units (1) must not affect the contact between the probe and the surface of the pipe (8), and the formula is: .

3. An electronic device, comprising: A memory storing executable program code; A processor coupled to the memory; characterized in that: the processor calls the executable program code stored in the memory to execute the system as described in any one of claims 1-2.

4. A computer storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the system according to any one of claims 1 to 2 is executed.

5. A computer program product, comprising a computer program, characterized in that: When the computer program is executed by a processor, the system according to any one of claims 1 to 2 is executed.

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