Wading bridge underwater pile foundation spatial form and fixing object thickness detection method, system and equipment and medium

Abstract

The invention discloses a method, a system and equipment for detecting the spatial form of an underwater pile foundation of a wading bridge and the thickness of a fixing object, and a medium. The method comprises the following steps: obtaining point cloud data of the complete form of an underwater pile group foundation; processing the obtained point cloud data of the complete form of the underwater pile group foundation to obtain an underwater pile foundation axis; the inclination is calculated based on the axis of the underwater pile foundation, the service state of the underwater pile foundation is evaluated with the tangent value of the inclination as an evaluation index, and whether the underwater pile foundation has significant spatial form changes or not is judged; a pile foundation appearance model is established based on the final underwater pile foundation axis and the pile foundation radius design value, the distance from the point cloud to the pile foundation surface is calculated, point cloud data are screened according to the distance, and a hard fixing object point cloud model is obtained; and performing noise interference correction on the distance between the attachment point cloud model and the surface of the pile foundation, and calculating to obtain a hard organism attachment thickness mean value. According to the method, the service state of the underwater batter pile can be accurately evaluated, and the attachment condition of the ocean fixing objects can be quantified.

Description

Technical Field

[0001] This invention belongs to the field of civil engineering bridge inspection technology, and particularly relates to a method, system, equipment and medium for detecting the spatial morphology and thickness of underwater pile foundations and anchorages of bridges in water-related areas. Background Technology

[0002] Underwater load-bearing structures of bridges and marine engineering projects are constantly exposed to complex marine environments. Their spatial morphological parameters (including inclination and axial deviation) and the geometric characteristics of surface hard attachments (such as shellfish and corals) directly affect the structure's load-bearing capacity and durability. Currently, the inspection of such underwater structures mainly relies on manual diving surveys or single-sensor scanning techniques, but these traditional methods have significant shortcomings in terms of efficiency and data accuracy. Manual diving surveys are not only time-consuming and labor-intensive, but also limited by underwater visibility and the diver's subjective judgment, making it difficult to accurately assess the morphology of pile foundations covered by biofilm. Single-sensor scanning techniques (such as optical imaging) are easily affected by water turbidity and the surface characteristics of biofilm, leading to reduced data reliability.

[0003] Three-dimensional sonar technology based on acoustic principles provides a new technical approach for underwater detection in deep-water and turbid-water environments, but its application in marine environments still faces significant challenges. Due to the propagation characteristics of underwater acoustic signals, sonar point cloud data in marine environments typically suffers from low resolution and strong noise interference. The presence of biological deposits further increases the difficulty of data analysis. The acoustic reflection characteristics of the biological deposit layer and the pile foundation overlap, making it difficult for traditional point cloud processing methods to effectively distinguish their geometric boundaries, thus failing to accurately reconstruct the true spatial morphology of the pile foundation. Furthermore, existing technologies lack the ability to quantitatively analyze biological deposits on the entire structure, resulting in an inability to comprehensively assess the impact of deposits on structural safety. This technical bottleneck limits the further application of sonar point cloud technology in underwater structure inspection. Summary of the Invention

[0004] Purpose of the invention: The purpose of this invention is to provide a method for detecting the spatial morphology and thickness of underwater pile foundations for water-crossing bridges, which can accurately assess the service status of underwater inclined piles and quantify the attachment status of marine anchorages.

[0005] A second objective of this invention is to provide a system.

[0006] A third objective of this invention is to provide an electronic device.

[0007] A fourth objective of this invention is to provide a computer-readable storage medium.

[0008] Technical Solution: To achieve the above objectives, this invention discloses a method for detecting the spatial morphology and thickness of fixed objects in underwater pile foundations of bridges navigating waterways, comprising the following steps: (1) Use a three-dimensional real-time sonar system to conduct multi-directional scanning of the underwater foundation of the coastal bridge and obtain point cloud data of the complete shape of the underwater pile foundation. (2) The point cloud data of the complete shape of the underwater pile foundation is processed to obtain the underwater pile foundation axis; (2.1) Perform PCA principal component analysis on the obtained pile foundation point cloud data to obtain the principal axis direction vector, calculate the angle between the principal axis direction vector and the Z-axis, and determine whether the pile foundation point cloud data is an inclined pile point cloud or a vertical pile point cloud by the angle. For the inclined pile point cloud, perform inclined pile spatial transformation to convert it into a vertical pile point cloud. (2.2) Perform equidistant cyclic slicing on the vertical pile point cloud along the vertical Z-axis, and perform circular fitting on each slice point cloud to obtain the center and radius of the slice; (2.3) Collect all the center points of the slices to form an initial axis point set, perform spatial inverse transformation on the initial axis point set of the inclined pile point cloud to obtain the axis feature point set; based on the axis feature point set, fit to obtain the initial axis, and filter the axis feature points to obtain the effective feature point set; (2.4) Fit the effective feature point set to obtain the final underwater pile foundation axis and axis equation; (3) Calculate the inclination based on the underwater pile foundation axis, and use the inclination tangent as the evaluation index to evaluate the service status of the underwater pile foundation and determine whether the underwater pile foundation has undergone significant spatial morphological changes. (4) Based on the final underwater pile foundation axis and pile foundation radius design values, establish the pile foundation appearance model, calculate the distance from the point cloud to the pile foundation surface, filter the point cloud data according to the distance, and obtain the hard attachment point cloud model; use the adaptive Gaussian weighting function to correct the noise interference between the attachment point cloud model and the pile foundation surface, and calculate the mean thickness of hard biological attachment based on the adaptive Gaussian weighting function.

[0009] Optionally, step (2.1) specifically includes the following steps: The pile foundation point cloud data obtained in step (1) PCA principal component analysis was performed to obtain the principal axis direction vectors. Calculate the principal axis direction vector With Z-axis The included angle Through the included angle Determine the point cloud data of the pile foundation Pointing clouds for inclined piles Or vertical pile point cloud Specifically, when the included angle When the angle is greater than the set angle, the pile foundation point cloud data Pointing clouds for inclined piles When the included angle When the angle is not greater than the set angle, the pile foundation point cloud data For vertical pile point cloud For vertical pile point clouds Recorded as vertical pile point cloud For oblique pile point cloud Based on the included angle and principal axis direction vector Constructing the rotation matrix using Rodrigues' rotation formula Rotation matrix The calculation formula is: , The point cloud is arranged around the geometric center. Rotation Align the main axis with the Z-axis to complete the oblique pile point cloud. Towards vertical pile point cloud The spatial transformation is calculated using the following formula: , in, Pointing clouds for inclined piles The geometric center is calculated as follows: , In the formula, N is the number of points in the point cloud. Point cloud for pile foundation The coordinate values.

[0010] Optionally, step (2.2) specifically includes the following steps: Set slice thickness parameters The cloud of vertical pile points approximately parallel to the Z-axis obtained in step (2.1) Perform equidistant slices along the vertical Z-axis, with a slice distance of... , by The step size is the minimum value. Towards the maximum value Perform cyclic slicing; use the least squares method to perform circular fitting on the point cloud of each slice to obtain the center of the slice. and radius ; For each slice of point cloud, the least squares objective equation is first established: , In the formula, Let be the objective equation, and the parameters to be solved in the objective equation are: , This refers to the number of point clouds in the current slice. Point cloud for pile foundation The X and Y axis coordinates of the mid-slice point cloud were obtained using a particle swarm optimization algorithm. Optimize the solution by taking the Z-axis of the sliced ​​point cloud as the median of the point cloud. Using the Z-axis coordinate of the sliced ​​circle, we obtain the optimal fitted circle model and the center of the slice. and radius .

[0011] Optionally, step (2.3) specifically includes the following steps: Collect the centers of all slices Construct the initial axis point set , cloud point of inclined pile initial axis point set pass Inverse transformation yields the set of axis feature points in real space. The specific expression is: , Based on axis feature point set The initial axis L1 is obtained by performing a spatial linear least squares fitting method, and the point cloud is calculated accordingly. The median of the nearest neighbor distance and the set of axis feature points The distance between the point cloud and the initial axis L1 , retain those that meet The point cloud of the axis feature points is the effective feature point set. .

[0012] Optionally, step (2.4) specifically includes the following steps: for the effective feature point set A second-order least squares fit is performed to obtain the final underwater pile foundation axis L2. The equation of the final underwater pile foundation axis L2 is: In the formula, the axial direction vector of the underwater pile foundation axis L2 is... for , These are the coordinates of the axis points. Let the coordinates of any point on the axis be denoted as . .

[0013] Optionally, step (3) specifically includes the following steps: (3.1) Calculate the inclination , with the tangent of the inclination angle The evaluation indicators are used to assess the service status of underwater pile foundations, among which... Determine the allowable deviation of the tilt angle tangent. : , (3.2) When the tangent of the inclination angle is... When the following formula is satisfied, it indicates that the underwater pile foundation has not undergone significant changes in spatial morphology and its service condition meets the design requirements: , In the formula, The design value of the tangent of the pile foundation inclination angle is calculated using the following formula. , This is the design value of the pile foundation inclination angle; when the tangent of the inclination angle is... If the following formula is not satisfied, it indicates that the underwater pile foundation has undergone significant spatial morphological changes.

[0014] Optionally, step (4) specifically includes the following steps: (4.1) Based on the final underwater pile foundation axis L2 and the design value of pile foundation radius R design Establish a pile foundation appearance model and calculate the point cloud. Distance to the pile foundation surface The calculation formula is as follows: , In the formula, For point clouds The coordinates of the midpoint i; This is the design value for the pile foundation radius; The vector represents the magnitude, i.e., the length; × represents the cross product of vectors. based on Eliminate those that meet the requirements Points, retain point clouds China conforms Point cloud; for satisfying of Sort in descending order and fit a polynomial curve to determine the inflection point of the curve. The maximum bioattachment thickness at the target bridge site was determined through literature review. ,Pick and The smaller one is the outlier threshold of the pile foundation sonar point cloud. Further elimination Point cloud data, retaining those that conform to Point cloud is a point cloud model of hard fixed objects. The specific calculation formula is as follows: , (4.2) To overcome the influence of small-scale noise in the data, it is assumed that the sonar point cloud The noise follows a Gaussian distribution, i.e., the distance in step (4.1) is... An adaptive Gaussian weighting function is used. For fixed object point cloud model Distance from the pile foundation surface The adaptive Gaussian weighting function is calculated using the following formula for noise interference correction: , In the formula, the mean μ and standard deviation σ are derived from the distance δ. i The result is obtained by fitting the Gaussian distribution function; Based on adaptive Gaussian weight function The average thickness of hard bio-attachment was calculated. The thickness calculation formula is as follows: , In the formula, Point cloud model for fixed objects The distance from the pile foundation surface; N is the number of point clouds.

[0015] Based on the same inventive concept, this invention discloses a system for detecting the spatial morphology and thickness of fixed objects in underwater pile foundations of bridges navigable by sonar point clouds, comprising: The point cloud data acquisition module is used to conduct multi-directional scanning of the underwater foundation of coastal bridges using a surveying vessel equipped with a three-dimensional real-time sonar system, and to acquire point cloud data of the complete shape of the underwater pile foundation. The pile foundation axis determination module processes the point cloud data of the complete underwater pile foundation to obtain the underwater pile foundation axis. It performs PCA principal component analysis on the obtained pile foundation point cloud data to obtain the principal axis direction vector, calculates the angle between the principal axis direction vector and the Z-axis, and determines whether the pile foundation point cloud data is an inclined pile point cloud or a vertical pile point cloud. For inclined pile point clouds, it performs an inclined pile spatial transformation to obtain a vertical pile point cloud. The vertical pile point cloud is processed into equidistant cyclic slices along the vertical Z-axis direction, and each slice point cloud is fitted with a circle to obtain the center and radius of the slice. All slice center points are collected to form an initial axis point set. The initial axis point set of the inclined pile point cloud is subjected to an inverse spatial transformation to obtain an axis feature point set. Based on the axis feature point set, the initial axis is fitted, and the axis feature points are filtered to obtain an effective feature point set. The effective feature point set is fitted to obtain the final underwater pile foundation axis and axis equation. The spatial morphology judgment module is used to calculate the inclination based on the underwater pile foundation axis, and use the inclination tangent as the evaluation index to evaluate the service status of the underwater pile foundation and determine whether the underwater pile foundation has undergone significant spatial morphology changes. The attachment thickness determination module is used to establish a pile foundation appearance model based on the final underwater pile foundation axis and pile foundation radius design values, calculate the distance from the point cloud to the pile foundation surface, filter the point cloud data according to the distance, and obtain a hard attachment point cloud model. An adaptive Gaussian weighting function is used to correct the noise interference of the distance between the attachment point cloud model and the pile foundation surface, and the average thickness of hard biological attachment is calculated based on the adaptive Gaussian weighting function.

[0016] Based on the same inventive concept, the present invention provides an electronic device including a processor and a storage medium; The storage medium is used to store instructions; The processor is configured to operate according to the instructions to perform the steps of the method described above.

[0017] Based on the same inventive concept, the present invention provides a computer-readable storage medium having a computer program stored thereon, characterized in that the program, when executed by a processor, implements the steps of the method described above.

[0018] Beneficial Effects: Compared with existing technologies, this invention has the following significant advantages: This invention can accurately assess the service status of underwater inclined piles and quantify the attachment status of marine fixed materials; this invention can effectively eliminate noise interference and the influence of fixed materials in sonar point clouds, accurately extracting the spatial axis equation of the pile foundation, and has the advantage of strong anti-interference compared to traditional algorithms such as cylindrical fitting; this invention can sensitively detect minute and gradual attitude changes, thereby scientifically judging whether the pile foundation has suffered from settlement, slippage, or deflection, providing a quantitative basis for structural safety early warning; this invention avoids the systematic errors caused by direct measurement based on sonar point clouds and the low efficiency of detection based on manually carried thickness measuring instruments, and can obtain reliable assessment values ​​of the thickness of hard fixed materials in the pile foundation, providing accurate data support for studying the laws of biological attachment and assessing its impact on structural load and corrosion. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the process in this invention; Figure 2 This is a sonar point cloud model of an underwater inclined pile of a bridge in this invention; Figure 3 The diagram shows the effect of extracting the axis of the underwater inclined pile using the present invention. Figure 4 A point cloud model of an underwater inclined pile rigid anchorage for applying the present invention; Figure 5 This is a diagram showing the thickness distribution of the underwater inclined pile rigid anchor along the z-axis for applying the present invention. Detailed Implementation

[0020] The technical solution of the present invention will be further described below with reference to the accompanying drawings.

[0021] Example 1: As Figure 1 As shown, this invention primarily serves the technical field of underwater bridge structure morphology identification, and its application is to underwater bridge structures. This invention discloses a method for detecting the spatial morphology and thickness of fixed structures in underwater pile foundations of water-crossing bridges, comprising the following steps: (1) Using a survey vessel equipped with a three-dimensional real-time sonar system, multi-directional scanning of the underwater foundation of the coastal bridge was carried out to obtain point cloud data of the complete shape of the underwater pile foundation.

[0022] This invention obtains point cloud data of the complete morphology of the underwater pile foundation through step (1), which serves as the data foundation for all subsequent precise analysis and quantification. By employing high-precision sonar scanning technology, millions of three-dimensional spatial coordinate points on the pile foundation surface can be acquired non-contactly and from all directions, forming a complete "digital twin". Compared with traditional underwater cameras, manual probing, or two-dimensional sonar, the high-density three-dimensional sonar point cloud contains rich geometric and spatial information of the pile foundation surface, making it possible to perform precise quantitative calculations of dimensions, morphology, and spatial relationships from any angle and any position. This is a prerequisite for subsequent axis extraction, tilt calculation, and thickness statistics. In addition, this invention avoids the problem of overgeneralization caused by insufficient measurement points, positional deviations, or insufficient data information in traditional underwater measurement methods, ensuring the comprehensiveness and representativeness of the obtained data and providing solid data support for overall condition assessment.

[0023] (2) The point cloud data of the complete shape of the underwater pile foundation is processed to obtain the axis of the underwater pile foundation.

[0024] (2.1) Perform PCA principal component analysis on the obtained pile foundation point cloud data to obtain the principal axis direction vector, calculate the angle between the principal axis direction vector and the Z-axis, and determine whether the pile foundation point cloud data is an inclined pile point cloud or a vertical pile point cloud by the angle. For the inclined pile point cloud, perform inclined pile spatial transformation to convert it into a vertical pile point cloud.

[0025] Step (2.1) specifically includes the following steps: The pile foundation point cloud data obtained in step (1) PCA principal component analysis was performed to obtain the principal axis direction vectors. Calculate the principal axis direction vector With Z-axis The included angle Through the included angle Determine the point cloud data of the pile foundation Pointing clouds for inclined piles Or vertical pile point cloud Specifically, when the included angle When the angle is greater than the set angle, the pile foundation point cloud data Pointing clouds for inclined piles When the included angle When the angle is not greater than the set angle, the pile foundation point cloud data For vertical pile point cloud For vertical pile point clouds Recorded as vertical pile point cloud For oblique pile point cloud Based on the included angle and principal axis direction vector Constructing the rotation matrix using Rodrigues' rotation formula Rotation matrix The calculation formula is: , The point cloud is arranged around the geometric center. Rotation Align the main axis with the Z-axis to complete the oblique pile point cloud. Towards vertical pile point cloud The spatial transformation is calculated using the following formula: , in, Pointing clouds for inclined piles The geometric center is calculated as follows: , In the formula, N is the number of points in the point cloud. Point cloud for pile foundation The coordinate values.

[0026] (2.2) Perform equidistant cyclic slicing on the vertical pile point cloud along the vertical Z-axis, and perform circular fitting on each slice point cloud to obtain the center and radius of the slice.

[0027] Step (2.2) specifically includes the following steps: Set slice thickness parameters The cloud of vertical pile points approximately parallel to the Z-axis obtained in step (2.1) Perform equidistant slices along the vertical Z-axis, with a slice distance of... , by The step size is the minimum value. Towards the maximum value Perform cyclic slicing; use the least squares method to perform circular fitting on the point cloud of each slice to obtain the center of the slice. and radius ; For each slice of point cloud, the least squares objective equation is first established: , In the formula, Let be the objective equation, and the parameters to be solved in the objective equation are: , This refers to the number of point clouds in the current slice. Point cloud for pile foundation The X and Y axis coordinates of the mid-slice point cloud were obtained using a particle swarm optimization algorithm. Optimize the solution by taking the Z-axis of the sliced ​​point cloud as the median of the point cloud. Using the Z-axis coordinate of the sliced ​​circle, we obtain the optimal fitted circle model and the center of the slice. and radius .

[0028] (2.3) Collect all the center points of the slices to form the initial axis point set, perform spatial inverse transformation on the initial axis point set of the inclined pile point cloud to obtain the axis feature point set; based on the axis feature point set, fit to obtain the initial axis, and filter the axis feature points to obtain the effective feature point set.

[0029] Step (2.3) specifically includes the following steps: Collect the centers of all slices Construct the initial axis point set , cloud point of inclined pile initial axis point set pass Inverse transformation yields the set of axis feature points in real space. The specific expression is: , Based on axis feature point set The initial axis L1 is obtained by performing a spatial linear least squares fitting method, and the point cloud is calculated accordingly. The median of the nearest neighbor distance and the set of axis feature points The distance between the point cloud and the initial axis L1 , retain those that meet The point cloud of the axis feature points is the effective feature point set. .

[0030] (2.4) Fit the effective feature point set to obtain the final underwater pile foundation axis and axis equation.

[0031] Step (2.3) specifically includes the following steps: for the effective feature point set A second-order least squares fit is performed to obtain the final underwater pile foundation axis L2. The equation of the final underwater pile foundation axis L2 is: In the formula, the axial direction vector of the underwater pile foundation axis L2 is... for , These are the coordinates of the axis points. Let the coordinates of any point on the axis be denoted as . .

[0032] Step (2) of this invention is a key abstraction and dimensionality reduction process that realizes the transformation from "surface" data to "line" features, which directly determines the accuracy of subsequent tilt assessment and hard fixation thickness measurement. Step (2) of this invention, through iterative point cloud slice analysis, circle fitting and quadratic spatial line fitting algorithms, can effectively eliminate noise interference and the influence of fixation in sonar point clouds, and accurately extract the spatial axis equation of the pile foundation. Compared with traditional algorithms such as cylindrical fitting, it has the advantage of strong anti-interference. This axis is the theoretical center line of the pile foundation, rather than a line connecting a certain point on the surface, so it can better reflect the overall spatial attitude of the pile foundation and provide a stable and reliable baseline for tilt calculation.

[0033] (3) Calculate the inclination based on the underwater pile foundation axis, and use the tangent of the inclination angle as the evaluation index to evaluate the service status of the underwater pile foundation and determine whether the underwater pile foundation has undergone significant spatial morphological changes.

[0034] Step (3) specifically includes the following steps: (3.1) Calculate the inclination Based on the GB 50202-2018 standard, the tangent value of the inclination angle is used. The evaluation indicators are used to assess the service status of underwater pile foundations, among which... GB 50202-2018 specifies the permissible deviation of the inclination tangent. : , (3.2) When the tangent of the inclination angle is... When the following formula is satisfied, it indicates that the underwater pile foundation has not undergone significant changes in spatial morphology and its service condition meets the design requirements: , In the formula, The design value of the tangent of the pile foundation inclination angle is calculated using the following formula. , This is the design value of the pile foundation inclination angle; when the tangent of the inclination angle is... If the following formula is not satisfied, it indicates that the underwater pile foundation has undergone significant spatial morphological changes.

[0035] Step (3) of this invention transforms abstract axis data into intuitive and comparable engineering evaluation indicators, enabling precise diagnosis of the service status of pile foundations. By calculating the angle (or its tangent) between the axis and the design vertical or design oblique direction, the current tilt status of the pile foundation can be quantified most directly and essentially, avoiding errors based on surface point calculations. Furthermore, the axis extracted from high-precision sonar point clouds has a much higher angle calculation accuracy than traditional underwater probing or simple ranging methods. By accurately comparing with design values ​​and historical monitoring data, minute and gradual attitude changes can be sensitively detected, thereby scientifically determining whether the pile foundation has suffered settlement, slippage, or deflection, providing a quantitative basis for structural safety early warning.

[0036] (4) Based on the final underwater pile foundation axis and pile foundation radius design values, establish the pile foundation appearance model, calculate the distance from the point cloud to the pile foundation surface, filter the point cloud data according to the distance, and obtain the hard attachment point cloud model; use the adaptive Gaussian weighting function to correct the noise interference between the attachment point cloud model and the pile foundation surface, and calculate the mean thickness of hard biological attachment based on the adaptive Gaussian weighting function.

[0037] Step (4) specifically includes the following steps: (4.1) Based on the final underwater pile foundation axis L2 and the design value of pile foundation radius R design Establish a pile foundation appearance model and calculate the point cloud. Distance to the pile foundation surface The calculation formula is as follows: , In the formula, For point clouds The coordinates of the midpoint i; This is the design value for the pile foundation radius; The vector represents the magnitude, i.e., the length; × represents the cross product of vectors. based on Eliminate those that meet the requirements Points, retain point clouds China conforms Point cloud; for satisfying of Sort in descending order and fit a polynomial curve to determine the inflection point of the curve. The maximum bioattachment thickness at the target bridge site was determined through literature review. ,Pick and The smaller one is the outlier threshold of the pile foundation sonar point cloud. Further elimination Point cloud data, retaining those that conform to Point cloud is a point cloud model of hard fixed objects. The specific calculation formula is as follows: .

[0038] (4.2) To overcome the influence of small-scale noise in the data, it is assumed that the sonar point cloud The noise follows a Gaussian distribution, i.e., the distance in step (4.1) is... An adaptive Gaussian weighting function is used. For fixed object point cloud model Distance from the pile foundation surface The adaptive Gaussian weighting function is calculated using the following formula for noise interference correction: , In the formula, the mean μ and standard deviation σ are derived from the distance δ. i The result is obtained by fitting the Gaussian distribution function; Based on adaptive Gaussian weight function The average thickness of hard bio-attachment was calculated. The thickness calculation formula is as follows: , In the formula, Point cloud model for fixed objects The distance from the pile foundation surface; N is the number of point clouds.

[0039] Step (4) of this invention establishes an "ideal" cylindrical model centered on the extracted axis and with the design radius as the surface, and calculates the normal distance from each point cloud to the surface of the model. This accurately distinguishes points belonging to the pile foundation, points belonging to surface attachments, and outlier noise points, ensuring that each point involved in the thickness calculation is a valid hard attachment point, thus improving the reliability of the data. In addition, step (4) corrects the distance between the attachment point cloud and the pile foundation surface caused by sound velocity measurement errors, avoiding the systematic errors caused by direct measurement based on sonar point clouds and the inefficiency of detection based on manually carried thickness measuring instruments. This provides a reliable assessment value of the thickness of the hard attachments in the pile foundation, providing accurate data support for studying the laws of biological attachment and assessing its impact on structural load and corrosion.

[0040] This invention, through a technical chain of "global scanning - axis extraction - pile foundation spatial morphology recognition - attachment point cloud segmentation and feature quantification," is interconnected and progressively deepened, ultimately achieving an objective, accurate, and repeatable quantitative assessment of the spatial alignment of underwater pile foundations and the thickness of biological attachments, thus solving a key pain point in the detection of underwater concealed engineering projects.

[0041] Firstly, based on a three-dimensional real-time sonar measurement system, as shown in... Figure 2 The point cloud model of the underwater pile foundation of a bridge across water is shown; then, the method in step (2) is applied to process the sonar point cloud of a single pile to obtain the following result. Figure 3The diagram shows the extraction of the pile foundation axis, which is used to evaluate the tangent of the inclined pile's inclination angle. Based on the extracted pile foundation axis equation, and combined with the design radius of the underwater pile foundation of the bridge, a system is established as follows: Figure 4 The ideal pile foundation appearance model shown is used to classify the effective point cloud, i.e. Figure 4 The green point cloud was finally calculated using the attachment thickness formula with an adaptive Gaussian weighting function, as shown below. Figure 5 The diagram shows the vertical thickness distribution of the rigid anchor material on the inclined pile.

[0042] Example 2: This invention discloses a system for detecting the spatial morphology and thickness of fixed objects in underwater pile foundations of bridges across waterways based on sonar point clouds, comprising: The point cloud data acquisition module is used to conduct multi-directional scanning of the underwater foundation of coastal bridges using a surveying vessel equipped with a three-dimensional real-time sonar system, and to acquire point cloud data of the complete shape of the underwater pile foundation.

[0043] The pile foundation axis determination module is used to process the point cloud data of the complete shape of the underwater pile foundation to obtain the underwater pile foundation axis.

[0044] Principal component analysis (PCA) is performed on the obtained pile foundation point cloud data to obtain the principal axis direction vector. The angle between the principal axis direction vector and the Z-axis is calculated, and the angle is used to determine whether the pile foundation point cloud data is an inclined pile point cloud or a vertical pile point cloud. For inclined pile point clouds, an inclined pile spatial transformation is performed to convert them into vertical pile point clouds. The obtained pile foundation point cloud data... PCA principal component analysis was performed to obtain the principal axis direction vectors. Calculate the principal axis direction vector With Z-axis The included angle Through the included angle Determine the point cloud data of the pile foundation Pointing clouds for inclined piles Or vertical pile point cloud Specifically, when the included angle When the angle is greater than the set angle, the pile foundation point cloud data Pointing clouds for inclined piles When the included angle When the angle is not greater than the set angle, the pile foundation point cloud data For vertical pile point cloud For vertical pile point clouds Recorded as vertical pile point cloud For oblique pile point cloud Based on the included angle and principal axis direction vector Constructing the rotation matrix using Rodrigues' rotation formula Rotation matrix The calculation formula is: , The point cloud is arranged around the geometric center. Rotation Align the main axis with the Z-axis to complete the oblique pile point cloud. Towards vertical pile point cloud The spatial transformation is calculated using the following formula: , in, Pointing clouds for inclined piles The geometric center is calculated as follows: , In the formula, N is the number of points in the point cloud. Point cloud for pile foundation The coordinate values.

[0045] The vertical pile point cloud is cyclically sliced ​​at equal intervals along the vertical Z-axis. A circular fit is performed on each slice to obtain the center and radius of the slice. A slice thickness parameter is set within this process. The resulting cloud of vertical pile points approximately parallel to the Z-axis Perform equidistant slices along the vertical Z-axis, with a slice distance of... , by The step size is the minimum value. Towards the maximum value Perform cyclic slicing; use the least squares method to perform circular fitting on the point cloud of each slice to obtain the center of the slice. and radius ; For each slice of point cloud, the least squares objective equation is first established: , In the formula, Let be the objective equation, and the parameters to be solved in the objective equation are: , This refers to the number of point clouds in the current slice. Point cloud for pile foundation The X and Y axis coordinates of the mid-slice point cloud were obtained using a particle swarm optimization algorithm. Optimize the solution by taking the Z-axis of the sliced ​​point cloud as the median of the point cloud. Using the Z-axis coordinate of the sliced ​​circle, we obtain the optimal fitted circle model and the center of the slice. and radius .

[0046] An initial axis point set is constructed by collecting the centers of all slice circles. An inverse spatial transformation is performed on this initial axis point set of the inclined pile point cloud to obtain an axis feature point set. Based on this axis feature point set, an initial axis is fitted, and the axis feature points are selected to obtain an effective feature point set. This process involves collecting the centers of all slice circles. Construct the initial axis point set , cloud point of inclined pile initial axis point set pass Inverse transformation yields the set of axis feature points in real space. The specific expression is: , Based on axis feature point set The initial axis L1 is obtained by performing a spatial linear least squares fitting method, and the point cloud is calculated accordingly. The median of the nearest neighbor distance and the set of axis feature points The distance between the point cloud and the initial axis L1 , retain those that meet The point cloud of the axis feature points is the effective feature point set. ; Fitting the effective feature point set yields the final underwater pile foundation axis and axis equation; the effective feature point set... A second-order least squares fit is performed to obtain the final underwater pile foundation axis L2. The equation of the final underwater pile foundation axis L2 is: In the formula, the axial direction vector of the underwater pile foundation axis L2 is... for , These are the coordinates of the axis points. Let the coordinates of any point on the axis be denoted as . .

[0047] The spatial morphology assessment module calculates the inclination based on the underwater pile foundation's axis and uses the tangent of the inclination angle as an evaluation index to assess the service status of the underwater pile foundation and determine whether significant changes in its spatial morphology have occurred. The spatial morphology assessment module calculates the inclination. Based on the GB 50202-2018 standard, the tangent value of the inclination angle is used. The evaluation indicators are used to assess the service status of underwater pile foundations, among which... GB50202-2018 standard specifies the permissible deviation of the inclination tangent value. : , When the tangent of the inclination angle is When the following formula is satisfied, it indicates that the underwater pile foundation has not undergone significant changes in spatial morphology and its service condition meets the design requirements: , In the formula, The design value of the tangent of the pile foundation inclination angle is calculated using the following formula. , This is the design value of the pile foundation inclination angle; when the tangent of the inclination angle is... If the following formula is not satisfied, it indicates that the underwater pile foundation has undergone significant spatial morphological changes.

[0048] The attachment thickness determination module is used to establish a pile foundation appearance model based on the final underwater pile foundation axis and pile foundation radius design values, calculate the distance from the point cloud to the pile foundation surface, filter the point cloud data according to the distance, and obtain a hard attachment point cloud model. An adaptive Gaussian weighting function is used to correct the noise interference of the distance between the attachment point cloud model and the pile foundation surface, and the average thickness of hard biological attachment is calculated based on the adaptive Gaussian weighting function.

[0049] The module for determining the thickness of the anchorage is based on the final underwater pile foundation axis L2 and the design value of the pile foundation radius R. design Establish a pile foundation appearance model and calculate the point cloud. Distance to the pile foundation surface The calculation formula is as follows: , In the formula, For point clouds The coordinates of the midpoint i; This is the design value for the pile foundation radius; The vector represents the magnitude, i.e., the length; × represents the cross product of vectors. based on Eliminate those that meet the requirements Points, retain point clouds China conforms Point cloud; for satisfying of Sort in descending order and fit a polynomial curve to determine the inflection point of the curve. The maximum bioattachment thickness at the target bridge site was determined through literature review. ,Pick and The smaller one is the outlier threshold of the pile foundation sonar point cloud. Further elimination Point cloud data, retaining those that conform to Point cloud is a point cloud model of hard fixed objects. The specific calculation formula is as follows: , To overcome the influence of small-scale noise in the data, it is assumed that the sonar point cloud... The noise follows a Gaussian distribution, i.e., distance... An adaptive Gaussian weighting function is used. For fixed object point cloud model Distance from the pile foundation surface The adaptive Gaussian weighting function is calculated using the following formula for noise interference correction: , In the formula, the mean μ and standard deviation σ are derived from the distance δ. i The result is obtained by fitting the Gaussian distribution function; Based on adaptive Gaussian weight function The average thickness of hard bio-attachment was calculated. The thickness calculation formula is as follows: , In the formula, Point cloud model for fixed objects The distance from the pile foundation surface; N is the number of point clouds.

[0050] Example 3: An electronic device according to the present invention includes a processor and a storage medium; Storage media are used to store instructions; The processor is configured to operate according to the instructions to perform the steps of the method described above.

[0051] Example 4: A computer-readable storage medium according to the present invention stores a computer program thereon, which, when executed by a processor, implements the steps of the method described above.

Claims

1. A method for detecting the spatial morphology and thickness of fixed objects in underwater pile foundations of bridges navigating waterways, characterized in that, Includes the following steps: (1) Use a three-dimensional real-time sonar system to conduct multi-directional scanning of the underwater foundation of the coastal bridge and obtain point cloud data of the complete shape of the underwater pile foundation. (2) The point cloud data of the complete shape of the underwater pile foundation is processed to obtain the underwater pile foundation axis; (2.1) Perform PCA principal component analysis on the obtained pile foundation point cloud data to obtain the principal axis direction vector, calculate the angle between the principal axis direction vector and the Z-axis, and determine whether the pile foundation point cloud data is an inclined pile point cloud or a vertical pile point cloud by the angle. For the inclined pile point cloud, perform inclined pile spatial transformation to convert it into a vertical pile point cloud. (2.2) Perform equidistant cyclic slicing on the vertical pile point cloud along the vertical Z-axis, and perform circular fitting on each slice point cloud to obtain the center and radius of the slice; (2.3) Collect all the center points of the slices to form an initial axis point set, perform spatial inverse transformation on the initial axis point set of the inclined pile point cloud to obtain the axis feature point set; based on the axis feature point set, fit to obtain the initial axis, and filter the axis feature points to obtain the effective feature point set; (2.4) Fit the effective feature point set to obtain the final underwater pile foundation axis and axis equation; (3) Calculate the inclination based on the underwater pile foundation axis, and use the inclination tangent as the evaluation index to evaluate the service status of the underwater pile foundation and determine whether the underwater pile foundation has undergone significant spatial morphological changes. (4) Based on the final underwater pile foundation axis and pile foundation radius design values, establish the pile foundation appearance model, calculate the distance from the point cloud to the pile foundation surface, filter the point cloud data according to the distance, and obtain the hard attachment point cloud model; use the adaptive Gaussian weighting function to correct the noise interference between the attachment point cloud model and the pile foundation surface, and calculate the mean thickness of hard biological attachment based on the adaptive Gaussian weighting function.

2. The method for detecting the spatial morphology and thickness of fixed objects in underwater pile foundations of bridges across waterways according to claim 1, characterized in that: Step (2.1) specifically includes the following steps: The pile foundation point cloud data obtained in step (1) PCA principal component analysis was performed to obtain the principal axis direction vectors. Calculate the principal axis direction vector With Z-axis The included angle Through the included angle Determine the point cloud data of the pile foundation Pointing clouds for inclined piles Or vertical pile point cloud Specifically, when the included angle When the angle is greater than the set angle, the pile foundation point cloud data Pointing clouds for inclined piles When the included angle When the angle is not greater than the set angle, the pile foundation point cloud data For vertical pile point cloud For vertical pile point clouds Recorded as vertical pile point cloud For oblique pile point cloud Based on the included angle and principal axis direction vector Constructing the rotation matrix using Rodrigues' rotation formula Rotation matrix The calculation formula is: ， The point cloud is arranged around the geometric center. Rotation Align the main axis with the Z-axis to complete the oblique pile point cloud. Towards vertical pile point cloud The spatial transformation is calculated using the following formula: ， in, Pointing clouds for inclined piles The geometric center is calculated as follows: ， In the formula, N is the number of points in the point cloud. Point cloud for pile foundation The coordinate values.

3. The method for detecting the spatial morphology and thickness of fixed objects in underwater pile foundations of bridges across water, as described in claim 2, is characterized in that: Step (2.2) specifically includes the following steps: Set slice thickness parameters The cloud of vertical pile points approximately parallel to the Z-axis obtained in step (2.1) Perform equidistant slices along the vertical Z-axis, with a slice distance of... , by The step size is the minimum value. Towards the maximum value Perform cyclic slicing; use the least squares method to perform circular fitting on the point cloud of each slice to obtain the center of the slice. and radius ; For each slice of point cloud, the least squares objective equation is first established: ， In the formula, Let be the objective equation, and the parameters to be solved in the objective equation are: , This refers to the number of point clouds in the current slice. Point cloud for pile foundation The X and Y axis coordinates of the mid-slice point cloud were obtained using a particle swarm optimization algorithm. Optimize the solution by taking the Z-axis of the sliced ​​point cloud as the median of the point cloud. Using the Z-axis coordinate of the sliced ​​circle, we obtain the optimal fitted circle model and the center of the slice. and radius .

4. The method for detecting the spatial morphology and thickness of fixed objects in underwater pile foundations of bridges across water, as described in claim 3, is characterized in that: Step (2.3) specifically includes the following steps: Collect the centers of all slices Construct the initial axis point set , cloud of oblique pile initial axis point set pass Inverse transformation yields the set of axis feature points in real space. The specific expression is: ， Based on axis feature point set The initial axis L1 is obtained by performing a spatial linear least squares fitting method, and the point cloud is calculated accordingly. The median of the nearest neighbor distance and the set of axis feature points The distance between the point cloud and the initial axis L1 , retain those that meet The point cloud of the axis feature points is the effective feature point set. .

5. The method for detecting the spatial morphology and thickness of fixed objects in underwater pile foundations of bridges across waterways according to claim 4, characterized in that: Step (2.4) specifically includes the following steps: for the effective feature point set A second-order least squares fit is performed to obtain the final underwater pile foundation axis L2. The equation of the final underwater pile foundation axis L2 is: In the formula, the axial direction vector of the underwater pile foundation axis L2 is... for , These are the coordinates of the points on the axis. Let the coordinates of any point on the axis be denoted as . .

6. The method for detecting the spatial morphology and thickness of fixed objects in underwater pile foundations of bridges across water, as described in claim 5, is characterized in that: Step (3) specifically includes the following steps: (3.1) Calculate the inclination , with the tangent of the inclination angle The evaluation indicators are used to assess the service status of underwater pile foundations, among which... Determine the allowable deviation of the tilt angle tangent. : ， (3.2) When the tangent of the inclination angle is... When the following formula is satisfied, it indicates that the underwater pile foundation has not undergone significant changes in spatial morphology and its service condition meets the design requirements: ， In the formula, The design value of the tangent of the pile foundation inclination angle is calculated using the following formula. , This is the design value of the pile foundation inclination angle; when the tangent of the inclination angle is... If the following formula is not satisfied, it indicates that the underwater pile foundation has undergone significant spatial morphological changes.

7. The method for detecting the spatial morphology and thickness of fixed objects in underwater pile foundations of bridges across waterways according to claim 5, characterized in that: Step (4) specifically includes the following steps: (4.1) Based on the final underwater pile foundation axis L2 and the design value of pile foundation radius R design Establish a pile foundation appearance model and calculate the point cloud. Distance to the pile foundation surface The calculation formula is as follows: ， In the formula, For point clouds The coordinates of the midpoint i; This is the design value for the pile foundation radius; The vector represents its magnitude, i.e., its length; × represents the cross product of vectors. based on Eliminate those that meet the requirements Points, retain point clouds China conforms Point cloud; for satisfying of Sort in descending order and fit a polynomial curve to determine the inflection point of the curve. The maximum bioattachment thickness at the target bridge site was determined through literature review. ,Pick and The smaller one is the outlier threshold of the pile foundation sonar point cloud. Further elimination Point cloud data, retaining those that conform to Point cloud is a point cloud model of hard fixed objects. The specific calculation formula is as follows: ， (4.2) To overcome the influence of small-scale noise in the data, it is assumed that the sonar point cloud The noise follows a Gaussian distribution, i.e., the distance in step (4.1) is... An adaptive Gaussian weighting function is used. For fixed object point cloud model Distance from the pile foundation surface The adaptive Gaussian weighting function is calculated using the following formula for noise interference correction: ， In the formula, the mean μ and standard deviation σ are derived from the distance δ. i The result is obtained by fitting the Gaussian distribution function; Based on adaptive Gaussian weight function The average thickness of hard bio-attachment was calculated. The thickness calculation formula is as follows: ， In the formula, Point cloud model for fixed objects The distance from the pile foundation surface; N is the number of point clouds.

8. A system for detecting the spatial morphology and thickness of fixed objects in underwater pile foundations of bridges navigating waterways, characterized in that, include: The point cloud data acquisition module is used to perform multi-directional scanning of the underwater foundation of coastal bridges using a three-dimensional real-time sonar system to acquire point cloud data of the complete shape of the underwater pile foundation. The pile foundation axis determination module is used to process the point cloud data of the complete shape of the underwater pile foundation to obtain the underwater pile foundation axis. Principal component analysis (PCA) is performed on the obtained pile foundation point cloud data to obtain the principal axis direction vector. The angle between the principal axis direction vector and the Z-axis is calculated, and the angle is used to determine whether the pile foundation point cloud data is an inclined pile point cloud or a vertical pile point cloud. For inclined pile point clouds, an inclined pile spatial transformation is performed to convert them into vertical pile point clouds. The vertical pile point cloud is then processed into equidistant cyclic slices along the vertical Z-axis direction. Circular fitting is performed on each slice point cloud to obtain the center and radius of the slice. All slice center points are collected to form an initial axis point set. An inverse spatial transformation is performed on the initial axis point set of the inclined pile point cloud to obtain the axis feature point set. Based on the axis feature point set, the initial axis is fitted, and the axis feature points are selected to obtain the effective feature point set. The effective feature point set is fitted to obtain the final underwater pile foundation axis and axis equation. The spatial morphology judgment module is used to calculate the inclination based on the underwater pile foundation axis, and use the inclination tangent as the evaluation index to evaluate the service status of the underwater pile foundation and determine whether the underwater pile foundation has undergone significant spatial morphology changes. The attachment thickness determination module is used to establish a pile foundation appearance model based on the final underwater pile foundation axis and pile foundation radius design values, calculate the distance from the point cloud to the pile foundation surface, filter the point cloud data according to the distance, and obtain a hard attachment point cloud model. An adaptive Gaussian weighting function is used to correct the noise interference of the distance between the attachment point cloud model and the pile foundation surface, and the average thickness of hard biological attachment is calculated based on the adaptive Gaussian weighting function.

9. An electronic device, characterized in that, Including processor and storage media; The storage medium is used to store instructions; The processor is configured to operate according to the instructions to perform the steps of the method according to any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by a processor, the program implements the steps of the method according to any one of claims 1 to 7.

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