Method for identifying interference signals of ferromagnetic objects around water supply and drainage pipeline

Abstract

The invention belongs to the technical field of water supply and drainage safety, and particularly relates to a method for recognizing interference signals of ferromagnetic objects around a water supply and drainage pipeline. Comprising the following steps: S1, collecting related data of on-site water supply and drainage pipelines; s2, carrying out interference-free magnetic signal collection on related pipelines; s3, magnetic signal collection is carried out on related pipelines when interference exists; s4, comparing and analyzing the magnetic signal data of the pipeline without interference and the magnetic gradient component signal characteristics of the pipeline in the X, Y and Z directions under the interference signal of the ferromagnetic interferent; s5, judging whether ferromagnetic substance interference exists or not according to the component change condition; and S6, finding out unknown pipeline interference data for verification, and analyzing whether the periphery of the pipeline is interfered by ferromagnetic substances or not by observing component change characteristics. The method has the beneficial effects that the position of an interference signal can be accurately identified, the influence of the interference signal on a pipeline detection signal is eliminated, the health state of the pipeline can be accurately judged, and unnecessary maintenance and intervention can be avoided, so that the maintenance cost is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of water supply and drainage safety, and in particular relates to a method for identifying interference signals from ferromagnetic objects around water supply and drainage pipes. Background Art

[0002] When water supply and drainage pipes are buried underground, uneven soil settlement can occur due to varying properties of the surrounding soil or external factors (such as nearby excavation projects and changes in groundwater levels). Some areas of the pipe bottom sink more, while others sink less, resulting in uneven support for the pipe. This uneven support creates additional bending stress in the pipe, leading to stress concentration in areas where the pipe and soil are in poor contact. Therefore, detecting stress concentration in ductile iron pipes and the extent of stress concentration is essential for their safe operation. This prevents safety incidents and environmental pollution caused by pipeline damage and leakage, ensures their normal operation and extends their service life, and maintains the safety and stability of the surrounding environment and facilities. However, when inspecting water supply and drainage pipes, interference signals from surrounding ferromagnetic objects can significantly impact the test results. Therefore, identifying ferromagnetic interference signals is crucial for the prevention and maintenance of water supply and drainage pipes, and is also directly related to public safety and environmental protection.

[0003] At present, there is no method for identifying the interference signals of ferromagnetic objects around the detection process at home and abroad, and there is no method for identifying the interference signals of ferromagnetic objects around water supply and drainage pipes. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for identifying interference signals of ferromagnetic objects around water supply and drainage pipelines. This method can overcome the existing technical defects, process the on-site water supply and drainage pipeline detection signals, identify the interference position and interference situation of the surrounding ferromagnetic objects on the pipeline signals, and by eliminating the interference position, the stress damage state of the pipeline can be truly identified to ensure the safe operation of the pipeline.

[0005] The technical solution of the present invention is as follows: A method for identifying ferromagnetic interference signals around water supply and drainage pipes, comprising the following steps:

[0006] S1: Collect relevant information on on-site water supply and drainage pipelines;

[0007] S2: Collect magnetic signals from relevant pipelines without interference;

[0008] S3: Collect magnetic signals from relevant pipelines when there is interference;

[0009] S4: Compare and analyze the magnetic signal data of the pipeline without interference and the magnetic gradient component signal characteristics in the X, Y, and Z directions under the interference signal of ferromagnetic interferers;

[0010] S5: Determine whether there is ferromagnetic interference based on the component changes;

[0011] S6: Find the data of unknown pipeline interference for verification, and analyze whether the pipeline is interfered by ferromagnetic objects by observing the component change characteristics.

[0012] The relevant information in step S1 includes pipeline length, pipe material, pipe diameter, buried depth, elevation mileage, and route.

[0013] Step S2 includes:

[0014] (1) Place the pipeline in a blank area without any ferromagnetic interference objects around the pipeline;

[0015] (2) The pipeline is inspected using the PMSI-Sentinel 2.0, a three-axis high-precision pipeline magnetic stress testing system;

[0016] (3) Magnetic gradient sensor #1 and magnetic gradient sensor #2 are located on both sides of the non-contact magnetic gradiometer. By performing differential analysis on the signals collected by the magnetic gradient sensors on both sides of the non-contact magnetic gradiometer, the interference of the geomagnetic signal can be eliminated. The calculation formula is shown in formula (1):

[0017]

[0018] In formula (1), B x1 、B y1 、B z1 、B x2 、B y2 With B z2 is the x-, y-, and z-axis components of the magnetic induction intensity of the 1# magnetic gradient sensor and the 2# magnetic gradient sensor set, G x , G y With G z is the three-axis component of the magnetic gradient signal, L is the distance between the two sensors, and G is the magnetic gradient modulus.

[0019] Step S3 includes:

[0020] (1) Select a pipe of the same material and diameter, place the pipe in the same location as in step S2 for testing, place a ferromagnetic interferer next to the pipe, and change the size and distance of the ferromagnetic interferer;

[0021] (2) Experimental testing is carried out at the same detection height to obtain the relevant magnetic signal results of the pipeline under the interference signal of ferromagnetic interference, including the magnetic gradient component signals in the X, Y, and Z directions.

[0022] The judgment rules in step S4 are as follows: under the influence of ferromagnetic interference, the X-direction magnetic gradient component of the magnetic signal remains unchanged; the Y-direction magnetic gradient component of the magnetic signal forms a single peak signal with an intensity more than twice the signal variation amplitude when there is no interference; the Z-direction magnetic gradient component of the magnetic signal forms a sinusoidal fluctuation of a single peak and valley signal with an intensity more than twice the signal variation amplitude when there is no interference. If the above rules are met, it is determined that there is ferromagnetic interference.

[0023] The beneficial effects of the present invention are that it can accurately identify the location of interference signals, eliminate the impact of interference signals on pipeline detection signals, and help accurately determine the health status of pipelines, thereby avoiding unnecessary repairs and interventions, thereby reducing maintenance costs and improving the economic efficiency of pipeline management. The present invention is applicable to most water supply and drainage pipelines and can analyze and determine the magnetic detection signals of different water supply and drainage pipelines, identifying the location of interference signals in the magnetic signal detection results of water supply and drainage pipelines, thereby eliminating the impact of interference signals on the judgment of the true status of the pipeline, making the magnetic detection results more accurate and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of pipeline magnetic signal detection results without interference on a DN100 pipeline.

[0025] Figure 2 This is a schematic diagram of the pipeline magnetic signal detection results without interference on a DN200 pipeline;

[0026] Figure 3 This is a schematic diagram of the pipeline magnetic signal detection results without interference on a DN300 pipeline;

[0027] Figure 4 This is a schematic diagram of pipeline magnetic signal detection results when the DN100 pipeline is disturbed;

[0028] Figure 5 This is a schematic diagram of pipeline magnetic signal detection results when the DN200 pipeline is interfered with;

[0029] Figure 6 This is a schematic diagram of the pipeline magnetic signal detection results when the DN300 pipeline is interfered. DETAILED DESCRIPTION

[0030] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0031] The present invention provides a method for identifying ferromagnetic interference signals around water supply and drainage pipes, comprising the following steps:

[0032] S1: Collect relevant information on on-site water supply and drainage pipelines;

[0033] The relevant information includes data such as pipeline length, pipe material, pipe diameter, burial depth, elevation mileage, and path.

[0034] S2: Collect magnetic signals from relevant pipelines without interference. The specific steps are as follows:

[0035] (1) Place the pipeline in a blank area without any ferromagnetic interference objects around the pipeline;

[0036] (2) The pipeline is inspected using the three-axis high-precision pipeline magnetic stress testing system PMSI-Sentinel 2.0, which mainly consists of a multi-functional data acquisition box, a data transmission cable, a non-contact magnetic gradiometer, an engineering host computer and a three-axis fluxgate sensor.

[0037] (3) Magnetic gradient sensor #1 and magnetic gradient sensor #2 are located on both sides of the non-contact magnetic gradiometer. The interference of geomagnetic signals can be eliminated by differentiating the signals collected by the magnetic gradient sensors on both sides of the non-contact magnetic gradiometer. The calculation formula is shown in formula (1). Therefore, the magnetic gradient component is used for analysis in subsequent analysis.

[0038]

[0039] In formula (1), B x1 、B y1 、B z1 、B x2 、B y2 With B z2 The x, y, and z axis components of the magnetic induction intensity collected by the 1# magnetic gradient sensor and the 2# magnetic gradient sensor (these two magnetic gradient sensors belong to the sensing elements of the magnetic gradiometer, one on each side) are in nT; G x , G y With G z is the triaxial component of the magnetic gradient signal, nT / m; L is the distance between the two sensors, m; G is the magnetic gradient modulus, nT / m.

[0040] After differential calculation, the magnetic gradient component signals in the X, Y, and Z directions are obtained. The detection results of DN100, DN200, and DN300 pipelines without interference are as follows: Figure 1 、 Figure 2 、 Figure 3As shown. Without interference from steel bars, the overall changes in the X, Y, and Z components of the magnetic gradient are gentle, all forming oblique straight lines. Compared to the Y and Z components, the rate of change of the X component is greater, but the magnetic signal changes of the three pipes are not consistent. The X component of the magnetic gradient of the DN100 gradually increases with the increase in the number of acquisition points, while the Y and Z components change linearly. The X component of the magnetic gradient of the DN200 first increases, then decreases, and finally increases again with the increase in the number of acquisition points. The peak and trough amplitudes are 200 nT·m-1. The Y component of the magnetic gradient has small fluctuations, while the Z component has peaks. The X component of the magnetic gradient of the DN300 pipeline gradually increases with the increase in the number of acquisition points, while the Y and Z components have smaller trends, first increasing and then gradually leveling off.

[0041] S3: Collect magnetic signals from relevant pipelines when there is interference. The specific steps are as follows:

[0042] (1) Select a pipe of the same material and diameter, place the pipe in the same location as in step S2 for testing, place a ferromagnetic interferer next to the pipe, and change the size and distance of the ferromagnetic interferer;

[0043] (2) Experimental testing is carried out at the same detection height to obtain the relevant magnetic signal results of the pipeline under the interference signal of ferromagnetic interference, including the magnetic gradient component signals in the X, Y, and Z directions.

[0044] The embodiments of the present invention are as follows:

[0045] The specific steps for collecting magnetic signals from DN100, DN200, and DN300 pipes in the presence of interference are as follows:

[0046] (1) Place DN100, DN200, and DN300 pipes in the same location for testing, place ferromagnetic interference objects next to the pipes, and change the size and distance of the ferromagnetic interference objects;

[0047] (2) Experimental testing was carried out at the same detection height to obtain the relevant magnetic signal results of the pipeline under the interference signal of ferromagnetic interference, including the magnetic gradient component signals in the X, Y, and Z directions. The detection results are as follows: Figure 4 、 Figure 5 、 Figure 6 shown.

[0048] S4: Compare and analyze the magnetic signal data of the pipeline when there is no interference and the magnetic gradient component signal characteristics in the X, Y, and Z directions under the interference signal of ferromagnetic interferers.

[0049] S5: Determine the presence of ferromagnetic interference based on component changes. The rules are as follows: In the presence of a ferromagnetic interference object, the magnetic signal's X-direction magnetic gradient component remains unchanged; the magnetic signal's Y-direction magnetic gradient component forms a single peak signal with an intensity at least twice the amplitude of the signal variation in the absence of interference; and the magnetic signal's Z-direction magnetic gradient component forms a sinusoidal fluctuation with a single peak and valley signal with an intensity at least twice the amplitude of the signal variation in the absence of interference. If these rules are met, ferromagnetic interference is determined.

[0050] S6: Use the component change characteristics to find the data of unknown pipeline interference for verification, and analyze whether the pipeline is interfered by ferromagnetic objects by observing the component change characteristics.

[0051] In this example, the magnetic signals of DN100, DN200, and DN300 pipes with and without ferromagnetic interference are verified:

[0052] Observe the magnetic signals of DN100 pipe with and without ferromagnetic interference, such as Figure 1 and Figure 4 As shown in the figure, the X component of the magnetic gradient remained unchanged; the Y component produced a single peak signal, with the maximum Y component amplitude varying by 1709 nT·m-1, more than double the amplitude of the signal in the absence of interference. The Z component of the magnetic gradient had an amplitude of 4000 nT·m-1, more than double the amplitude of the signal in the absence of interference. The signal characteristics met the judgment criteria.

[0053] Observe the magnetic signals of DN200 pipe with and without ferromagnetic interference, such as Figure 2 and Figure 5 As shown in the figure, the X component of the magnetic gradient remains unchanged; the Y component of the magnetic gradient produces a single peak signal, with the maximum Y component amplitude varying by 650 nT·m-1, more than twice the amplitude of the signal variation in the absence of interference. The Z component of the magnetic gradient has an amplitude of 900 nT·m-1, more than twice the amplitude of the signal variation in the absence of interference. The signal characteristics meet the judgment criteria.

[0054] Observe the magnetic signals of DN300 pipe with and without ferromagnetic interference, such as Figure 3 and Figure 6 As shown in the figure, the X component of the magnetic gradient remains unchanged; the Y component of the magnetic gradient produces a single peak signal, with the maximum Y component amplitude varying by 600 nT·m-1, more than twice the amplitude of the signal in the absence of interference. The Z component of the magnetic gradient has an amplitude of 850 nT·m-1, more than twice the amplitude of the signal in the absence of interference. The signal characteristics meet the judgment criteria.

[0055] The verification results show that the signal characteristics of each pipeline meet the interference signal judgment rules and can effectively distinguish the presence or absence of ferromagnetic interference.

Claims

1. A method for identifying ferromagnetic interference signals around water supply and drainage pipes, characterized in that: The following steps are involved: S1: Collect relevant information on on-site water supply and drainage pipelines; S2: Collect magnetic signals from relevant pipelines without interference; S3: Collect magnetic signals from relevant pipelines when there is interference; S4: Compare and analyze the magnetic signal data of the pipeline without interference and the magnetic gradient component signal characteristics in the X, Y, and Z directions under the interference signal of ferromagnetic interferers; S5: Determine whether there is ferromagnetic interference based on the component changes; S6: Find the data of unknown pipeline interference for verification, and analyze whether the pipeline is interfered by ferromagnetic objects by observing the component change characteristics.

2. A method for identifying ferromagnetic interference signals around water supply and drainage pipes according to claim 1, characterized in that: The relevant information in step S1 includes pipeline length, pipe material, pipe diameter, buried depth, elevation mileage, and route.

3. A method for identifying ferromagnetic interference signals around water supply and drainage pipes according to claim 1, characterized in that: Step S2 includes: (1) Place the pipeline in a blank area without any ferromagnetic interference objects around the pipeline; (2) The pipeline is inspected using the PMSI-Sentinel 2.0, a three-axis high-precision pipeline magnetic stress testing system; (3) Magnetic gradient sensor #1 and magnetic gradient sensor #2 are located on both sides of the non-contact magnetic gradiometer. By performing differential analysis on the signals collected by the magnetic gradient sensors on both sides of the non-contact magnetic gradiometer, the interference of the geomagnetic signal can be eliminated. The calculation formula is shown in formula (1): In formula (1), B x1 、B y1 、B z1 、B x2 、B y2 With B z2 is the x-, y-, and z-axis components of the magnetic induction intensity of the 1# magnetic gradient sensor and the 2# magnetic gradient sensor set, G x , G y With G z is the three-axis component of the magnetic gradient signal, L is the distance between the two sensors, and G is the magnetic gradient modulus.

4. A method for identifying ferromagnetic interference signals around water supply and drainage pipes according to claim 1, characterized in that: Step S3 includes: (1) Select a pipe of the same material and diameter, place the pipe in the same location as in step S2 for testing, place a ferromagnetic interference object next to the pipe, and change the size and distance of the ferromagnetic interference object.

5. A method for identifying ferromagnetic interference signals around water supply and drainage pipes as claimed in claim 4, characterized in that: Step S3 includes: (2) Experimental testing is carried out at the same detection height to obtain the relevant magnetic signal results of the pipeline under the interference signal of ferromagnetic interference, including the magnetic gradient component signals in the X, Y, and Z directions.

6. A method for identifying ferromagnetic interference signals around water supply and drainage pipes according to claim 1, characterized in that: The judgment rule in step S4 includes that under the influence of ferromagnetic interference, the X-direction magnetic gradient component of the magnetic signal remains unchanged; the Y-direction magnetic gradient component of the magnetic signal forms a single peak signal with an intensity more than twice the signal variation amplitude when there is no interference.

7. A method for identifying ferromagnetic interference signals around water supply and drainage pipes according to claim 6, characterized in that: The judgment rule in step S4 includes that the Z-direction magnetic gradient component of the magnetic signal forms a sinusoidal fluctuation of a single peak and valley signal, and the intensity is more than twice the signal change amplitude when there is no interference. If the above rules are met, it is determined that there is ferromagnetic interference.

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