Municipal sewer pipe defect detection method and device

Abstract

The present invention relates to the field of electromagnetic wave detection technology, and more specifically to a method and device for detecting defects in municipal sewer pipes. First, a detection movement direction is obtained based on the degree of consistency of pipeline data detected by an electromagnetic wave detector in different directions, and pipeline data detection is performed along this direction. Then, based on the regularity of the pipeline data and the overall regularity of the pipeline data, the normality of the pipeline at the current detection location is obtained. Based on the normality of the pipeline at the current detection location, the location of the pipeline where defects may exist and the degree to which the electromagnetic wave frequency needs to be increased are obtained. Finally, the electromagnetic wave detection frequency is adjusted to detect the location of the pipeline where defects may exist. The present invention can solve the problem of the poor adaptability of single-frequency electromagnetic waves to different detection requirements, and improve the efficiency of sewer pipe detection and the accuracy of defect identification.

Description

Technical Field

[0001] The present invention relates to the technical field of electromagnetic wave detection, and in particular to a method and device for detecting defects in municipal sewer pipes. Background Art

[0002] Municipal sewer pipes are important infrastructure for urban construction, serving as a drainage channel for rainwater and sewage within cities. As sewer pipes age naturally or are affected by factors such as underground construction, leaks and blockages are inevitable. If not discovered and repaired in a timely manner, these problems will not only affect people's normal lives but may also cause disasters such as ground subsidence. Electromagnetic wave detectors can be used to detect sewer pipes. When used, specific lossless waves are emitted underground. The reflection, refraction, and propagation characteristics of electromagnetic waves in sewer pipes and buried layers are used to identify blockages, leaks, and structural damage in the pipes. This allows for effective maintenance and repair of sewer pipes, further extending the service life of the pipes and ensuring the efficient operation of urban drainage systems.

[0003] When using electromagnetic wave detectors to detect sewer pipes, due to the different road surface materials and depths of the sewer pipes, electromagnetic waves of the same frequency or single band often cannot adapt to the pipeline detection needs in different locations, resulting in insufficient detection results and difficulty in identifying defects and risks in the pipelines. Summary of the Invention

[0004] In order to solve the technical problem that the single-frequency electromagnetic wave in the existing technology has poor adaptability to different municipal sewer pipe defect detection requirements, the purpose of the present invention is to provide a municipal sewer pipe defect detection method and device. The technical solution adopted is as follows:

[0005] In a first aspect, a method for detecting defects in municipal sewer pipes is provided, the method comprising:

[0006] Step S1: obtaining a detection movement direction based on the consistency of pipeline data detected by the electromagnetic wave detector in different directions, and performing pipeline data detection along this direction;

[0007] Step S2: obtaining the regularity of the pipeline data in a column according to the slope change of each pipeline edge data in the moving direction;

[0008] Step S3: Obtain the overall regularity of the pipeline data based on the regularity of each column of pipeline data and the standard deviation of the average slope change of all columns of pipelines;

[0009] Step S4: Obtaining the normality of the pipeline at the current detection position based on the consistency of the pipeline data in the current moving direction and the overall regularity of the pipeline data in the direction at the current detection position;

[0010] Step S5: Based on the normality of the pipeline at the current detection position, the position of the pipeline that may have defects and the degree to which the electromagnetic wave frequency needs to be increased are obtained;

[0011] Step S6: Adjust the electromagnetic wave detection frequency to detect the location of the pipeline where defects may exist.

[0012] Furthermore, the step S1 specifically includes:

[0013] The consistency of pipeline data in different directions is obtained by using the standard deviation of each column of pipeline data in different directions of the current detection position of the electromagnetic wave detector;

[0014] The direction corresponding to the maximum consistency of pipeline data in different directions is taken as the pipeline laying direction and detection movement direction, and pipeline data detection is performed along this direction.

[0015] Furthermore, step S2 specifically includes:

[0016] Obtaining a slope change of each pipe edge data in each column in the moving direction according to the horizontal coordinate value of each pipe data in each column in the moving direction and the depth coordinate value of each pipe data in each column in the moving direction;

[0017] The regularity of the pipeline data in a column is obtained according to the absolute value of the difference in slope change of adjacent pipeline edge data in a column of pipelines in the moving direction.

[0018] Furthermore, step S3 specifically includes:

[0019] According to the regularity of the pipeline data of each column in the upper half of the pipeline in the moving direction and the standard deviation of the average slope change of all columns in the upper half of the pipeline in the detection moving direction, the overall regularity of the pipeline data in the upper half of the pipeline in this direction is obtained;

[0020] According to the regularity of the pipeline data of each column in the lower half of the pipeline in the moving direction and the standard deviation of the average slope change of all columns in the lower half of the pipeline in the detection moving direction, the overall regularity of the pipeline data in the lower half of the pipeline in this direction is obtained;

[0021] The sum of the overall regularity of the pipeline data in the upper and lower parts of the pipeline in this direction is calculated to obtain the overall regularity of the pipeline data.

[0022] Furthermore, in step S4, the consistency of the pipeline data in the current moving direction and the overall regularity of the pipeline data in the current detection position in this direction are both positively correlated with the normality of the pipeline at the current detection position.

[0023] Furthermore, in step S5, the obtaining of the pipeline position that may have defects is specifically as follows: if the normality of the pipeline at the current detection position is less than the average normality of all detection positions before the current detection position, it is determined that there may be a pipeline defect at the current detection position.

[0024] Furthermore, in step S5, the degree to which the electromagnetic wave frequency needs to be increased is obtained by: obtaining the degree to which the electromagnetic wave frequency needs to be increased according to the normality of the pipeline at the current detection position and the average normality of all detection positions before the current detection position.

[0025] Furthermore, in step S6, the adjusting of the electromagnetic wave detection frequency is specifically: obtaining the adjusted frequency of the electromagnetic wave according to the current electromagnetic wave frequency, the initial setting frequency of the electromagnetic wave, and the degree to which the electromagnetic wave frequency needs to be increased.

[0026] Furthermore, in step S6, adjusting the electromagnetic wave detection frequency to detect the location of the pipeline where a defect may exist specifically includes:

[0027] Obtaining the adjusted frequency of the electromagnetic wave according to the current frequency of the electromagnetic wave, the initially set frequency of the electromagnetic wave, and the degree to which the frequency of the electromagnetic wave needs to be increased;

[0028] According to the data consistency of the column where each detection point is located in the moving direction and the data regularity of the column where each detection point is located in the vertical direction corresponding to the moving direction, the abnormal performance degree of each detection point is obtained;

[0029] If the abnormal performance degree of a detection point is greater than a preset first threshold, it is determined that the detection point is abnormal;

[0030] If the difference between the proportion of detection points with abnormal pipeline performance detected by the electromagnetic wave frequency after adjustment and the proportion of detection points with abnormal pipeline performance detected by the electromagnetic wave frequency before adjustment is less than a preset second threshold, it is determined that the electromagnetic wave frequency has been adjusted to the desired level. Otherwise, the electromagnetic wave frequency is adjusted according to the current electromagnetic wave frequency, the initial setting frequency of the electromagnetic wave, and the degree to which the electromagnetic wave frequency needs to be increased until it is adjusted to the desired level.

[0031] The location of the pipeline where defects may occur is detected based on the adjusted electromagnetic wave frequency.

[0032] In a second aspect, a municipal sewer pipe defect detection device is provided, the device comprising:

[0033] The detection direction acquisition module is used to obtain the detection movement direction according to the consistency of the pipeline data detected by the electromagnetic wave detector in different directions, and perform pipeline data detection along this direction;

[0034] A regularity acquisition module is used to acquire the regularity of the pipeline data in a column according to the slope change of each pipeline edge data in the moving direction;

[0035] The overall regularity acquisition module is used to obtain the overall regularity of pipeline data based on the regularity of each column of pipeline data and the standard deviation of the average slope change of all columns of pipelines;

[0036] A normality acquisition module is used to acquire the normality of the pipeline at the current detection position based on the consistency of the pipeline data in the current moving direction and the overall regularity of the pipeline data in the direction at the current detection position;

[0037] The defect location acquisition module is used to obtain the location of the pipeline where defects may exist based on the normality of the pipeline at the current detection location;

[0038] The frequency adjustment module is used to obtain the degree to which the electromagnetic wave frequency needs to be increased according to the normality of the pipeline at the current detection position;

[0039] The defect location detection module is used to detect the location of pipelines where defects may exist by adjusting the electromagnetic wave detection frequency.

[0040] The present invention has the following beneficial effects:

[0041] 1. Improved adaptability to different sewer pipe detection requirements. This invention monitors the stability of electromagnetic waves received by electromagnetic wave detectors during detection, analyzes the possibility of pipeline defects at the detection location, adjusts the electromagnetic wave frequency at the location where the pipeline defect may exist, and performs multiple detections. This solves the problem of the existing technology that single-frequency electromagnetic waves have poor adaptability to different detection requirements.

[0042] Second, it improves the efficiency of sewer pipe detection. The present invention uses electromagnetic wave detectors to obtain the consistency of pipeline data in different directions, analyzes the direction of the sewer pipe, and moves the detector along the direction of the sewer pipe for detection. This can quickly locate the pipeline direction and the detection movement direction, thereby improving the efficiency of sewer pipe detection.

[0043] 3. Improve the accuracy of sewer pipe defect identification. The present invention analyzes whether there are defects at the detection location based on the consistency and regularity of pipeline data obtained by electromagnetic wave detectors in the direction along the sewer pipe and in the vertical direction, as well as the impact of internal pipeline defects on the stability of electromagnetic waves. This can effectively narrow the pipeline defect identification range and perform more accurate detection near the pipeline defect location. According to the normality of the pipeline where the internal pipeline defect is suspected to exist, the electromagnetic wave frequency is adjusted. On the basis of ensuring that the pipeline can be completely detected, the electromagnetic wave frequency is increased as much as possible to obtain more accurate sewer pipe internal defect data and improve the accuracy of pipeline defect identification. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solutions and advantages of the embodiments of the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0045] Figure 1 A flow chart of a municipal sewer pipe defect detection method provided by one embodiment of the present invention.

[0046] Figure 2 A schematic diagram of different directions corresponding to pipeline data detected by an electromagnetic wave detector provided by an embodiment of the present invention;

[0047] Figure 3 A schematic diagram of establishing a coordinate system for a municipal sewer pipe provided by one embodiment of the present invention;

[0048] Figure 4 This is a block diagram of a municipal sewer pipe defect detection device provided by one embodiment of the present invention. DETAILED DESCRIPTION

[0049] To further illustrate the technical means and effectiveness of the present invention in achieving its intended objectives, the following, in conjunction with the accompanying drawings and preferred embodiments, describes in detail a method and apparatus for detecting defects in municipal sewer pipes according to the present invention, including its specific implementation, structure, features, and effectiveness. In the following description, different references to "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention relates.

[0050] The present invention addresses the following scenario: when using electromagnetic wave detectors to detect sewer pipes, because pipes at different locations have different requirements for electromagnetic wave penetration and resolution, setting a fixed electromagnetic wave frequency for detection cannot meet the detection needs of pipes at different locations, and the detection results obtained are often inaccurate. This embodiment addresses this problem by analyzing the adaptability of the current electromagnetic wave frequency to the pipe at the current detection location when the electromagnetic wave detector detects sewer pipe data and adjusting the electromagnetic wave frequency. This increases the electromagnetic wave penetration when detecting deeper pipes and increases the electromagnetic wave resolution when precise identification of pipe defects is required. This improves the robustness of the electromagnetic wave detector when detecting sewer pipes and enhances the accuracy of the detection results.

[0051] The following describes in detail a method and device for detecting defects in municipal sewer pipes provided by the present invention in conjunction with the accompanying drawings.

[0052] First, see Figure 1 , which shows a flow chart of a municipal sewer pipe defect detection method provided by one embodiment of the present invention, the method comprising the following steps:

[0053] Step S1: obtaining a detection moving direction according to the consistency of pipeline data detected by the electromagnetic wave detector in different directions, and performing pipeline data detection along this direction.

[0054] Among them, step S1 specifically includes: obtaining the consistency of pipeline data in different directions through the standard deviation of each column of pipeline data in different directions of the current detection position of the electromagnetic wave detector; taking the direction corresponding to the maximum value of the consistency of pipeline data in different directions as the pipeline laying direction and detection movement direction, and performing pipeline data detection along this direction.

[0055] More specifically, when detecting municipal sewer pipes, the electromagnetic wave frequency of the electromagnetic wave detector is typically in the range of 1 MHz to 2 GHz. This is because low-frequency electromagnetic waves have strong penetration but low resolution and are suitable for detecting larger pipes or deeper underground. High-frequency electromagnetic waves have high resolution but weak penetration and are used for detecting smaller pipes or where high resolution is required. To balance the penetration and resolution of electromagnetic waves, in step S1 of this embodiment, the initial frequency of the electromagnetic wave detector is set to 100 MHz, and the initial detection interval is set to 1 second based on the speed of the moving person.

[0056] Since the electromagnetic wave detector mainly calculates the depth information of each detection point on the pipeline through the propagation time of the reflected signal, and obtains the pipeline position data corresponding to the pipeline depth data based on the depth and the angle of the reflected signal relative to the emission point, the pipeline data in this embodiment includes: extracting the characteristics of the sewer pipeline based on the received reflected and scattered electromagnetic wave signals, and determining the position of each detection point in the sewer pipeline, where the position is obtained through the depth and horizontal position data of the detection point, and the detection points are evenly distributed on the pipeline, and the distance between adjacent detection points is 1 mm, which can be adjusted automatically.

[0057] Because sewer pipes have different depths at different locations, the detector must be positioned as close to the pipe as possible to minimize the impact of depth variations when analyzing internal defects. To ensure that the electromagnetic wave detector can fully cover the entire pipe area during detection, the detector's movement must be aligned with the pipe's direction. Therefore, the detector's movement direction must be adjusted based on the changes in the pipe's structural characteristics detected each time compared to the previous detection.

[0058] See Figure 2 The diagram shows a schematic diagram of a coordinate system for establishing a municipal sewer pipe. In this implementation, when using an electromagnetic wave detector to perform electromagnetic wave detection of the sewer pipe, the consistency of the pipe data detected by the electromagnetic wave detector is analyzed in four different directions, namely, the left front, the front, and the right front, in the horizontal direction of the ground; among them, the direction corresponding to 2 represents the front direction, the direction corresponding to 1 represents the right front direction, and the direction corresponding to 3 represents the left front direction.

[0059] In this embodiment, the mathematical formula for the consistency of the detected pipeline data in different directions is as follows:

[0060]

[0061] Where, Indicates the number of pipeline columns in the rth direction in the current detection data. Represents the standard deviation of the i-th column of pipeline data in the r-th direction at the current detection position (due to the site environment and worker operation during pipeline construction, each column of pipeline data is inevitably discrete, so ); Indicates the consistency of each column of pipeline data in the rth direction of the current detection position.

[0062] In the mathematical formula for the consistency of the detected pipeline data in different directions, the standard deviation of the pipeline data in the i-th column in the r-th direction at the front detection position is The smaller the value, the better the consistency of the pipeline data in the column, that is, the better the consistency of the pipeline data in each column in the direction of the corresponding current detection position; on the contrary, the standard deviation of the pipeline data in the i-th column in the r-th direction at the previous detection position is. The larger the value is, the worse the consistency of pipeline data in this column is, that is, the worse the consistency of pipeline data in each column in this direction at the corresponding current detection position is.

[0063] Furthermore, the electromagnetic wave detector should be along Move in the corresponding direction, that is, take the direction corresponding to the maximum consistency of the pipeline data in different directions as the pipeline laying direction and detection movement direction, and perform pipeline data detection along this direction.

[0064] Step S2: Obtain the regularity of the pipeline data in a column according to the slope variation of each pipeline edge data in the moving direction.

[0065] Step S2 specifically includes: obtaining the slope change of each pipe edge data in each column in the moving direction based on the horizontal coordinate value of each pipe data in each column in the moving direction and the depth coordinate value of each pipe data in each column in the moving direction; and obtaining the regularity of the pipe data in a column based on the absolute value of the difference in the slope change of adjacent pipe edge data in a column in the moving direction.

[0066] Since the detector is adjusted to move along the pipeline in step S1, when the sewer pipeline is functioning normally, each column of pipeline data detected along the direction of movement should be stable. However, when a defect in the sewer pipeline occurs, the detected pipeline data may mutate. For example, when a sewer pipeline leaks, the detected signal strength will decrease because water has a strong absorption capacity for electromagnetic waves. Furthermore, because water changes the propagation path of electromagnetic waves, the detected signal may become uneven. For another example, when a sewer pipeline is clogged, obstructing objects such as sediment may cause the signal to refract or scatter, resulting in an abnormal waveform. Therefore, the stability of the detection signal can be used to determine whether a pipeline defect may exist at the current detection location. To determine the stability of the detection signal, it is first necessary to determine the degree of regularity of each column of pipeline data.

[0067] See Figure 3 The following diagram shows pipeline data detected by an electromagnetic wave detector in different directions. For ease of illustration, in this implementation, a coordinate system is established during each detection, with the pipeline direction as the y-axis, the transverse direction perpendicular to the pipeline as the x-axis, and the z-axis perpendicular to the x- and y-axes and facing the interior of the pipeline as the z-axis. This system then obtains coordinate information for each detected pipeline location. To determine the degree of regularity in each column of pipeline data, it is necessary to calculate the regularity of pipeline data changes in the direction perpendicular to the movement direction (the y-axis). Since the pipeline is cylindrical, i.e., it exhibits an arc shape in the x-axis direction, the pipeline data in this direction should exhibit regular changes. However, if there are defects at the current detection location, the signal attenuation, enhancement, and scattering caused by the defects will disrupt this regularity in the detection data in the direction perpendicular to the movement direction.

[0068] In this embodiment, the mathematical formula for the slope change of the edge data of a pipe in a column of pipes in the moving direction is constructed as follows:

[0069]

[0070] Where, Indicates the x-coordinate value of the j-th pipe data in the i-th column of pipes in the moving direction, Indicates the depth coordinate value (z coordinate) of the jth pipeline data in the i-th column in this direction; Indicates the x-coordinate value of the j+1th pipe data in the i-th column of pipes in the moving direction, Indicates the depth coordinate value (z coordinate) of the j+1th pipeline data in the i-th column in this direction; Indicates the x-coordinate value of the j-1th pipeline data in the i-th column pipeline in the moving direction, Indicates the depth coordinate value (z coordinate) of the j-1th pipeline data in the i-th column in this direction; Indicates the slope change of the j-th pipe edge data in the i-th column in this direction.

[0071] In the above-mentioned mathematical formula for the slope change of a pipe edge data in a column of pipes in the moving direction, due to 、 、 Represent different coordinate values ​​in the x-coordinate direction, so there is no objection 、 Its value is not 0; Indicates the coordinates corresponding to the x, y, and z coordinate systems ( 、 、 ) and coordinates ( 、 、 ) corresponds to the slope of the pipe edge data in the xz plane; Indicates the coordinates corresponding to the x, y, and z coordinate systems ( 、 、 ) and coordinates ( 、 、 ) corresponds to the slope of the pipeline edge data in the xz plane; the difference between the two is the change in the slope of the j-th pipeline edge data in the i-th column in that direction.

[0072] In this embodiment, the mathematical formula for the regularity of each column of pipeline data is constructed as follows:

[0073]

[0074] Where, represents the slope change of the j-th pipe edge data in the i-th column in the moving direction; Indicates the slope change of the j+1th pipe edge data in the i-th column in the moving direction; Indicates the number of pipeline data contained in the i-th column in this direction; represents the summation function; Indicates the regularity of the pipeline data in the i-th column in this direction; is an exponential function with a natural constant as its base.

[0075] In the mathematical formula for the regularity of each column of pipeline data constructed above, the slope change of the adjacent pipeline edge data is Total quantity -1, The sum of the slope changes of all adjacent pipeline edge data is negatively correlated. The larger the value, the closer the slope changes of all adjacent pipeline edge data are, and the better the regularity of each column of pipeline data.

[0076] Step S3: Obtain the overall regularity of the pipeline data based on the regularity of each column of pipeline data and the standard deviation of the average slope change of all columns of pipelines.

[0077] Among them, step S3 specifically includes: obtaining the overall regularity of the pipeline data in the upper half of the pipeline in the direction of movement based on the regularity of the pipeline data in each column of the upper half of the pipeline in the direction of movement and detecting the standard deviation of the average slope change of all columns of the upper half of the pipeline in the direction of movement; obtaining the overall regularity of the pipeline data in the lower half of the pipeline in the direction of movement based on the regularity of the pipeline data in each column of the lower half of the pipeline in the direction of movement and detecting the standard deviation of the average slope change of all columns of the lower half of the pipeline in the direction of movement; and calculating the sum of the overall regularity of the pipeline data in the upper and lower halves of the pipeline in the direction to obtain the overall regularity of the pipeline data.

[0078] When using electromagnetic wave detectors to detect sewer pipes, due to their hollow cylindrical shape and the fact that they are typically made of a hard metal, the data detected at each column of detection points along the pipe should be essentially consistent under normal conditions. Furthermore, because a single detection location may detect two data values ​​(due to the cylindrical shape of the pipe), the data value received first at the same location is considered to represent the upper half of the pipe at that location, while the data received later is considered to represent the lower half of the pipe at that location, based on the order in which the detection signals were received. Furthermore, when sewer pipes are wide, electromagnetic wave detectors may only detect part of the upper and lower halves of the pipe, which may not be connected. Therefore, the regularity of data changes in the upper and lower halves of the sewer pipe are calculated separately.

[0079] Taking the upper half of the sewer pipe as an example, the mathematical calculation formula for the overall regularity of the pipeline data of the upper half of the sewer pipe constructed in this embodiment is as follows:

[0080]

[0081] Where, Indicates the overall regularity of the pipeline data in the upper half of the pipeline in this direction; Indicates the number of columns in the upper half of the pipe in the direction of movement, Indicates the regularity of the pipeline data in the i-th column of the upper half of the pipeline in the moving direction, represents the normalization function; It represents the standard deviation of the average slope change of all rows of pipes in the moving direction of the upper half of the pipe.

[0082] In the above mathematical calculation formula for the overall regularity of the pipeline data in the upper half of the sewer pipe, the regularity of the pipeline data in the i-th column in the upper half of the pipe in the moving direction is The overall regularity of the pipeline data in this direction compared to the upper part of the pipeline Positive correlation; when When the standard deviation of the average slope change of all rows of pipelines in the moving direction of the upper half of the pipeline is The overall regularity of the pipeline data in this direction compared to the upper part of the pipeline Negative correlation, the smaller the value, the more consistent the regularity of each column, that is, the better the overall regularity; When the average slope change data of all columns of pipelines in the moving direction of the upper half of the pipeline are consistent, the overall regularity of the pipeline data in this direction of the upper half of the pipeline is only the regularity of the pipeline data in the i-th column of the upper half of the pipeline in the moving direction. Positive correlation, with the standard deviation of the average slope change of all rows of pipes in the direction of movement of the upper half of the pipe Not relevant.

[0083] Similarly, obtain the overall regularity of the data in this direction in the lower half of the pipeline , and then obtain the overall regularity of the pipeline data.

[0084] In this embodiment, the mathematical calculation formula for the overall regularity of the constructed pipeline data is as follows:

[0085]

[0086] Where, Indicates the overall regularity of the pipeline data in the upper half of the pipeline in this direction; Indicates the overall regularity of the pipeline data in the lower half of the pipeline in this direction; Indicates the overall regularity of pipeline data.

[0087] In the mathematical calculation formula for the overall regularity of pipeline data constructed above, the overall regularity of the pipeline data in the upper half of the pipeline in this direction and the overall regularity of the pipeline data in the lower half of the pipeline in this direction are comprehensively considered, and the sum of the two is the overall regularity of the pipeline data.

[0088] Step S4: Obtain the normality of the pipeline at the current detection position based on the consistency of the pipeline data in the current moving direction and the overall regularity of the pipeline data in the direction at the current detection position.

[0089] In step S4, the consistency of the pipeline data in the current moving direction and the overall regularity of the pipeline data in the direction at the current detection position are both positively correlated with the normality of the pipeline at the current detection position.

[0090] In this embodiment, the mathematical calculation formula for the normality of the pipeline at the current detection position is constructed as follows:

[0091]

[0092] Where, Indicates the consistency of pipeline data in the current moving direction; Indicates the overall regularity of pipeline data in this direction at the current detection position; Indicates the normality of the pipeline at the current detection position.

[0093] In the above-constructed mathematical calculation formula for the normality of the pipeline at the current detection position, the overall regularity of the pipeline data in the direction of the current detection position and the consistency of the pipeline data in the current moving direction are both positively correlated with the normality of the pipeline at the current detection position. The better the overall regularity of the pipeline data in the direction of the current detection position and the better the consistency of the pipeline data in the current moving direction, the better the normality of the pipeline at the current detection position.

[0094] Step S5: According to the normality of the pipeline at the current detection position, the position of the pipeline where defects may occur and the degree to which the electromagnetic wave frequency needs to be increased are obtained.

[0095] In step S5, determining the location of a pipeline that may have a defect is specifically performed by: if the normality of the pipeline at the current detection location is less than the average normality of all detection locations prior to the current detection location, determining that a pipeline defect may exist at the current detection location. Determining the degree to which the electromagnetic wave frequency needs to be increased is specifically performed by: determining the degree to which the electromagnetic wave frequency needs to be increased based on the normality of the pipeline at the current detection location and the average normality of all detection locations prior to the current detection location.

[0096] Since the proportion of sewer pipe defects in the entire sewer pipe is small, that is, most areas in the pipe should be normal, and defects will have a greater impact on the electromagnetic wave signal, so the average normality of all detection positions before the current detection position is calculated. ,when When the detection position is detected, it is determined that there may be a pipeline defect.

[0097] Furthermore, if a pipeline defect is suspected at the detection location, the detector needs to stop at that location, adjust the electromagnetic wave frequency, and repeat the detection to more accurately identify the pipeline defect. During normal detection, a longer electromagnetic wave wavelength is required to more completely detect the internal structure of the pipeline. However, this increased electromagnetic wave penetration inevitably results in a loss of resolution, making it difficult to accurately locate the pipeline defect. Therefore, when a pipeline defect is suspected at the detection location, the electromagnetic wave frequency needs to be increased, which means the wavelength needs to be decreased.

[0098] In this embodiment, the mathematical calculation formula for the degree to which the electromagnetic wave frequency needs to be increased is as follows:

[0099]

[0100] Where, Indicates the normality of the pipeline at the current detection location; Indicates the average normality of all detection positions before the current detection position; Indicates the degree to which the frequency of electromagnetic waves needs to be increased. is the normalization function.

[0101] In the mathematical calculation formula for the degree to which the electromagnetic wave frequency needs to be increased, Only when the frequency of electromagnetic waves increases, When , it means that the pipeline has no defects and there is no need to increase the frequency of the electromagnetic wave; | It indicates the absolute value of the difference between the average value of the normality of all detection positions before the current detection position and the normality of the pipeline at the current detection position. The smaller the value, the less obvious the difference between the defect and the normal area is at the current electromagnetic wave frequency. Therefore, when there may be a pipeline defect at the detection position, it is necessary to increase the frequency of the electromagnetic wave, that is, to reduce the wavelength of the electromagnetic wave. It is negatively correlated with the degree to which the frequency of electromagnetic waves needs to be increased.

[0102] Step S6: Adjust the electromagnetic wave detection frequency to detect the location of the pipeline where defects may exist.

[0103] Wherein, in step S6, adjusting the electromagnetic wave detection frequency specifically includes: obtaining the adjusted frequency of the electromagnetic wave according to the current electromagnetic wave frequency, the initial setting frequency of the electromagnetic wave, and the degree to which the electromagnetic wave frequency needs to be increased.

[0104] The mathematical calculation formula for the adjusted electromagnetic wave frequency constructed in this embodiment is as follows:

[0105]

[0106] Where, Indicates the frequency of the electromagnetic wave after adjustment, Indicates the frequency of the current electromagnetic wave, Indicates the initial setting frequency of the electromagnetic wave, Indicates the degree to which the frequency of electromagnetic waves needs to be increased.

[0107] In the mathematical calculation formula for the adjusted electromagnetic wave frequency constructed above, through a linear equation, the current electromagnetic wave frequency is used as the adjustment base, the initial setting frequency adjustment reference of the electromagnetic wave, and the degree to which the electromagnetic wave frequency needs to be increased is used as the adjustment coefficient. The result shows the frequency of the electromagnetic wave after adjustment.

[0108] In addition, in step S6, the adjustment of the electromagnetic wave detection frequency to detect the position of the pipeline that may have defects specifically includes: obtaining the adjusted frequency of the electromagnetic wave according to the current electromagnetic wave frequency, the initial setting frequency of the electromagnetic wave, and the degree to which the electromagnetic wave frequency needs to be increased; obtaining the degree of abnormal performance of each detection point according to the data consistency of the column where each detection point is located in the moving direction and the data regularity of the column where each detection point is located in the vertical direction corresponding to the moving direction; if the abnormal performance degree of a detection point is greater than a preset first threshold, it is determined that the detection point exhibits abnormality; if the difference between the proportion of detection points with abnormal pipeline performance detected by the frequency of the electromagnetic wave after adjustment in all detection points and the proportion of detection points with abnormal pipeline performance detected by the frequency of the electromagnetic wave before adjustment in all detection points is less than a preset second threshold, it is determined that the electromagnetic wave frequency is adjusted in place; otherwise, the electromagnetic wave frequency is continued to be adjusted according to the current electromagnetic wave frequency, the initial setting frequency of the electromagnetic wave, and the degree to which the electromagnetic wave frequency needs to be increased until it is adjusted in place; and the position of the pipeline that may have defects is detected according to the electromagnetic wave frequency after adjustment.

[0109] Specifically, as the frequency of electromagnetic waves increases, the distance they travel becomes shorter, reducing the range of scattering and other effects. Therefore, the accuracy of current defect identification is analyzed based on the number of data points with abnormal performance.

[0110] In this embodiment, the abnormality level of each detection point is calculated based on the data performance of each detection point in the moving direction and the column perpendicular to the moving direction.

[0111] The mathematical calculation formula for the abnormal performance degree of each detection point constructed in this embodiment is as follows:

[0112]

[0113] Where, Indicates the degree of abnormal performance of the i-th detection point, Indicates the data consistency of the column where the i-th detection point is located in the moving direction, Indicates the data regularity of the column where the i-th detection point is located in the direction perpendicular to the moving direction.

[0114] In the mathematical calculation formula for the degree of abnormality at each detection point constructed above, according to the mathematical formula for the degree of consistency of pipeline data in different directions and the mathematical formula for the degree of regularity of each column of pipeline data, there is no doubt that ,and The degree of abnormal performance of the detection point is negatively correlated with the data consistency and data regularity of the column where the detection point is located. The better the data consistency and data regularity of the column where the detection point is located, the smaller the degree of abnormal performance of the detection point.

[0115] If the abnormal performance of a detection point is greater than a preset first threshold, the detection point is determined to be abnormal. The first threshold can be 0.5, that is, when , it is determined that the detection point exhibits abnormality.

[0116] If the percentage of detection points with abnormal pipeline performance detected by the adjusted electromagnetic wave frequency relative to the percentage of detection points with abnormal pipeline performance detected by the electromagnetic wave frequency before adjustment is less than a preset second threshold, the electromagnetic wave frequency adjustment is deemed to be in place. In this embodiment, the second threshold may be 0.1. That is, if the percentage of detection points with abnormal pipeline performance detected by the adjusted electromagnetic wave frequency relative to the percentage of detection points with abnormal pipeline performance detected by the electromagnetic wave frequency before adjustment is less than 0.1, the electromagnetic wave adjustment is in place. At this point, the overall range of the pipeline detected at the current electromagnetic wave frequency is reduced, that is, the electromagnetic wave frequency cannot detect the entire pipeline. The sewer pipeline data obtained at this time is used as the final data.

[0117] Finally, based on the detected pipeline data, a pipeline structural image is generated and defects are identified. Based on the depth information at each pipeline location obtained in the above process, an internal pipeline structural image is generated. Defects such as leaks and blockages are identified and marked within the internal pipeline structural image. All internal sewer defect information is fed back to the management system to facilitate maintenance planning.

[0118] In the second aspect, this embodiment provides a municipal sewer pipe defect detection device, see Figure 4 , which shows a block diagram of a municipal sewer pipe defect detection device provided by one embodiment of the present invention, the device comprising:

[0119] The detection direction acquisition module 101 is used to obtain the detection movement direction according to the consistency of the pipeline data detected by the electromagnetic wave detector in different directions, and perform pipeline data detection along this direction;

[0120] A regularity acquisition module 102 is configured to acquire the regularity of the pipeline data in a column according to the slope variation of each pipeline edge data in the moving direction;

[0121] The overall regularity acquisition module 103 is used to acquire the overall regularity of the pipeline data based on the regularity of each column of pipeline data and the standard deviation of the average slope change of all columns of pipelines;

[0122] The normality acquisition module 104 is used to acquire the normality of the pipeline at the current detection position based on the consistency of the pipeline data in the current moving direction and the overall regularity of the pipeline data in the direction at the current detection position;

[0123] The defect location acquisition module 105 is used to acquire the location of the pipeline where a defect may exist according to the normality of the pipeline at the current detection location;

[0124] The frequency adjustment module 106 is used to obtain the degree to which the electromagnetic wave frequency needs to be increased according to the normality of the pipeline at the current detection position;

[0125] The defect location detection module 107 is used to detect the location of the pipeline where a defect may exist by adjusting the electromagnetic wave detection frequency.

[0126] This embodiment provides a municipal sewer pipe defect detection method and apparatus. First, based on the consistency of pipeline data detected by an electromagnetic wave detector in different directions, a detection movement direction is obtained, and pipeline data detection is performed along this direction. Based on the slope change of each pipe edge data in a column of pipes in the movement direction, the regularity of the column of pipe data is obtained. Based on the regularity of each column of pipe data and the standard deviation of the average slope change of all columns of pipes, the overall regularity of the pipeline data is obtained. Next, based on the consistency of the pipeline data in the current movement direction and the overall regularity of the pipeline data in the current detection position in that direction, the normality of the pipeline at the current detection position is obtained. Based on the normality of the pipeline at the current detection position, the location of the pipeline that may have defects and the degree to which the electromagnetic wave frequency needs to be increased are determined. Finally, the electromagnetic wave detection frequency is adjusted to detect the location of the pipeline that may have defects. The above scheme improves adaptability to different sewer pipe detection requirements and improves sewer pipe detection efficiency. Furthermore, by analyzing the consistency of pipeline data in different directions obtained by the electromagnetic wave detector, the direction of the sewer pipe is analyzed, and the detector is moved along the direction of the sewer pipe for detection. This allows for rapid positioning of the pipeline direction and detection movement direction, thereby improving sewer pipe detection efficiency.

[0127] It should be noted that the order in which the embodiments of the present invention are described above is for illustrative purposes only and does not necessarily represent the superiority or inferiority of the embodiments. The processes depicted in the accompanying drawings do not necessarily require the specific order or sequential order shown to achieve the desired results. In certain embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0128] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and should all be included in the scope of protection of the present application.

Claims

1. A method for detecting defects in municipal sewer pipes, characterized in that: The method comprises: Step S1: obtaining a detection movement direction based on the consistency of pipeline data detected by the electromagnetic wave detector in different directions, and performing pipeline data detection along this direction; Step S2: obtaining the regularity of the pipeline data in a column according to the slope change of each pipeline edge data in the moving direction; Step S3: Obtain the overall regularity of the pipeline data based on the regularity of each column of pipeline data and the standard deviation of the average slope change of all columns of pipelines; Step S4: Obtaining the normality of the pipeline at the current detection position based on the consistency of the pipeline data in the current moving direction and the overall regularity of the pipeline data in the direction at the current detection position; Step S5: Based on the normality of the pipeline at the current detection position, the position of the pipeline that may have defects and the degree to which the electromagnetic wave frequency needs to be increased are obtained; Step S6: Adjust the electromagnetic wave detection frequency to detect the location of the pipeline where defects may exist.

2. A municipal sewer pipe defect detection method according to claim 1, characterized in that: Step S1 specifically includes: The consistency of pipeline data in different directions is obtained by using the standard deviation of each column of pipeline data in different directions of the current detection position of the electromagnetic wave detector; The direction corresponding to the maximum consistency of pipeline data in different directions is taken as the pipeline laying direction and detection movement direction, and pipeline data detection is performed along this direction.

3. A municipal sewer pipe defect detection method according to claim 1, characterized in that: Step S2 specifically includes: Obtaining a slope change of each pipe edge data in each column in the moving direction according to the horizontal coordinate value of each pipe data in each column in the moving direction and the depth coordinate value of each pipe data in each column in the moving direction; The regularity of the pipeline data in a column is obtained according to the absolute value of the difference in slope change of adjacent pipeline edge data in a column of pipelines in the moving direction.

4. A municipal sewer pipe defect detection method according to claim 1, characterized in that: Step S3 specifically includes: According to the regularity of the pipeline data of each column in the upper half of the pipeline in the moving direction and the standard deviation of the average slope change of all columns in the upper half of the pipeline in the detection moving direction, the overall regularity of the pipeline data in the upper half of the pipeline in this direction is obtained; According to the regularity of the pipeline data of each column in the lower half of the pipeline in the moving direction and the standard deviation of the average slope change of all columns in the lower half of the pipeline in the detection moving direction, the overall regularity of the pipeline data in the lower half of the pipeline in this direction is obtained; The sum of the overall regularity of the pipeline data in the upper and lower parts of the pipeline in this direction is calculated to obtain the overall regularity of the pipeline data.

5. A municipal sewer pipe defect detection method according to claim 1, characterized in that: In step S4, the consistency of the pipeline data in the current moving direction and the overall regularity of the pipeline data in the current detection position in this direction are both positively correlated with the normality of the pipeline at the current detection position.

6. A municipal sewer pipe defect detection method according to claim 1, characterized in that: In step S5, the step of obtaining the pipeline position that may have defects is as follows: if the normality of the pipeline at the current detection position is less than the average normality of all detection positions before the current detection position, it is determined that the pipeline may have defects at the current detection position.

7. A municipal sewer pipe defect detection method according to claim 1, characterized in that: In step S5, the degree to which the electromagnetic wave frequency needs to be increased is specifically obtained by: obtaining the degree to which the electromagnetic wave frequency needs to be increased according to the normality of the pipeline at the current detection position and the average normality of all detection positions before the current detection position.

8. A municipal sewer pipe defect detection method according to claim 1, characterized in that: In step S6, the adjusting of the electromagnetic wave detection frequency is specifically: obtaining the adjusted frequency of the electromagnetic wave according to the current electromagnetic wave frequency, the initially set frequency of the electromagnetic wave, and the degree to which the electromagnetic wave frequency needs to be increased.

9. A municipal sewer pipe defect detection method according to claim 1, characterized in that: In step S6, adjusting the electromagnetic wave detection frequency to detect the location of the pipeline where a defect may exist specifically includes: Obtaining the adjusted frequency of the electromagnetic wave according to the current frequency of the electromagnetic wave, the initially set frequency of the electromagnetic wave, and the degree to which the frequency of the electromagnetic wave needs to be increased; According to the data consistency of the column where each detection point is located in the moving direction and the data regularity of the column where each detection point is located in the vertical direction corresponding to the moving direction, the abnormal performance degree of each detection point is obtained; If the abnormal performance degree of a detection point is greater than a preset first threshold, it is determined that the detection point is abnormal; If the difference between the proportion of detection points with abnormal pipeline performance detected by the electromagnetic wave frequency after adjustment and the proportion of detection points with abnormal pipeline performance detected by the electromagnetic wave frequency before adjustment is less than a preset second threshold, it is determined that the electromagnetic wave frequency has been adjusted to the desired level. Otherwise, the electromagnetic wave frequency is adjusted according to the current electromagnetic wave frequency, the initial setting frequency of the electromagnetic wave, and the degree to which the electromagnetic wave frequency needs to be increased until it is adjusted to the desired level. The location of the pipeline where defects may occur is detected based on the adjusted electromagnetic wave frequency.

10. A municipal sewer pipe defect detection device, characterized in that: The device comprises: The detection direction acquisition module is used to obtain the detection movement direction according to the consistency of the pipeline data detected by the electromagnetic wave detector in different directions, and perform pipeline data detection along this direction; A regularity acquisition module is used to acquire the regularity of the pipeline data in a column according to the slope change of each pipeline edge data in the moving direction; The overall regularity acquisition module is used to obtain the overall regularity of pipeline data based on the regularity of each column of pipeline data and the standard deviation of the average slope change of all columns of pipelines; A normality acquisition module is used to acquire the normality of the pipeline at the current detection position based on the consistency of the pipeline data in the current moving direction and the overall regularity of the pipeline data in the direction at the current detection position; The defect location acquisition module is used to obtain the location of the pipeline where defects may exist based on the normality of the pipeline at the current detection location; The frequency adjustment module is used to obtain the degree to which the electromagnetic wave frequency needs to be increased according to the normality of the pipeline at the current detection position; The defect location detection module is used to detect the location of pipelines where defects may exist by adjusting the electromagnetic wave detection frequency.

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