Stay cable force calculation method based on three-dimensional scanning cable shape

Abstract

The invention discloses a stay cable force calculation method based on a three-dimensional scanning cable shape, and relates to the technical field of bridge detection, and the method comprises the steps: 1, obtaining an original point cloud of a stay cable based on a three-dimensional scanner, segmenting the scanned stay cable point cloud through employing a DBSCAN clustering algorithm, and rapidly and accurately obtaining the point cloud of each independent stay cable; 2, accurately extracting the cable shape of a single inhaul cable; and 3, calculating the cable force of the inhaul cable through a catenary formula by adopting an iteration method according to the shape of the inhaul cable extracted in the above step. According to the method, the cable force of the cable-stayed bridge cable can be rapidly and accurately calculated, and the defects that a traditional cable force testing method is too long in time and unstable in precision due to coupling of various parameters are overcome.

Description

Technical Field

[0001] The invention belongs to the technical field of bridge detection, and in particular is a method for calculating the cable force of a stay cable based on three-dimensional scanning of the cable shape. Background Art

[0002] In the field of engineering structures, cable-stayed bridges are a modern bridge structure with very complex design and construction. As an important component supporting the main beam of the bridge, the force characteristics of the cable-stayed cable directly affect the safety and operation efficiency of the bridge. Therefore, accurate testing and analysis of the mechanical characteristics of the cable-stayed cable is an important prerequisite for ensuring the safety of the cable-stayed bridge structure. Cable force testing is an important task that cable-supported bridges often have to do from construction to operation and maintenance. The accuracy of the cable force test directly affects the accuracy of the overall force analysis of the bridge.

[0003] Traditional methods for measuring the cable tension of cable-stayed bridges mainly include: pressure gauge method, pressure sensor method, magnetic flux method and frequency method. The pressure gauge method measures the cable tension by using the relationship between the hydraulic pressure of the jack cylinder and the tension of the cable. It is only used for measuring the cable tension during construction or cable replacement, and cannot measure the tensioned cable. The pressure sensor method tests the cable tension of cable-stayed bridges by using sensors anchored at the ends of the cables. It is expensive and needs to be pre-installed during the construction phase. It is rarely used in existing large-span cable-stayed bridges. The magnetic flux method uses the calibration relationship between the induced electromotive force and the cable stress to monitor the cable tension change. However, this method has high calibration requirements and is greatly affected by factors such as temperature. The accuracy of bridge cable tension detection during operation is poor. The frequency method cable tension test based on string vibration theory is widely used in construction control, state assessment and health monitoring of structures. However, the traditional string theory ignores the influence of the cable's bending stiffness, sag, and external damper, which sometimes leads to unacceptable errors in practical applications.

[0004] Currently, 3D laser scanning technology has been widely used in the construction field, but it is rarely used in bridge engineering, especially in the construction monitoring and measurement of large cable-stayed bridges. Summary of the invention

[0005] The present invention aims to overcome the deficiencies of the prior art and provide a method for calculating the cable force of a cable-stayed bridge based on three-dimensional scanning of the cable shape, so as to improve the efficiency and accuracy of the cable force test of a cable-stayed bridge, and solve the problems of long test time, low efficiency and unstable cable force calculation accuracy existing in traditional cable force tests, thereby effectively improving the accuracy, reliability and efficiency of cable force measurement of cable-stayed bridges.

[0006] In order to achieve the above-mentioned purpose, the present invention adopts the following technical scheme:

[0007] The method for calculating the cable force of a stay cable based on three-dimensional scanning of the cable shape of the present invention is characterized in that it comprises the following steps:

[0008] Step 1: Use a 3D laser scanner to obtain the original point cloud of multiple cables and transform it into a global Cartesian coordinate system to obtain a coordinate set of the 3D point cloud. ,in, is the coordinate of the i-th 3D point cloud, n is the total number of 3D point clouds of all cables, represents the coordinate of the i-th 3D point cloud in the x-axis direction, represents the coordinate of the i-th point in the y-axis direction, Represents the coordinate of the i-th point in the z-axis direction;

[0009] The x-axis coordinate and the coordinates in the z-axis direction The 2D coordinates that make up the i-th 3D point cloud , thus forming two-dimensional point cloud coordinate data ;

[0010] Step 2: Use DBSCAN clustering algorithm to Segmentation is performed to obtain a complete point cloud of each cable;

[0011] Step 3: Use the improved RANSAC algorithm to reduce the noise of the cross-sectional point cloud of each micro-segment on a single cable, and obtain the cross-sectional point cloud of each micro-segment on a single cable after noise reduction, and use it to fit the optimal circle model of the point cloud on the cross-sectional area of ​​each micro-segment and its fitting center and fitting radius;

[0012] Step 4: Connect the centers of each fitting circle in sequence to obtain the shape of a single cable;

[0013] Step 5: Calculate the cable force F of a single cable based on its shape.

[0014] The method for calculating the cable force of a stay cable based on three-dimensional scanning of the cable shape described in the present invention is also characterized in that the step 2 comprises the following steps:

[0015] Step 2.1: Define the minimum clustering radius as , the minimum number of point clouds within the fitting radius is p; the current number of clusters is C, and C=0 is initialized; i=1;

[0016] Step 2.2: As the cluster center, use the RegionQuery function to find The cluster radius All point cloud data in Neighbor point cloud, judge Is the total number of neighbor point clouds of the Cth cluster less than p? If so, mark the neighbor point clouds in the Cth cluster as noise points and execute step 2.4; otherwise, assign C+1 to C and The neighbor point clouds of form the Cth cluster and execute step 2.3;

[0017] Step 2.3: Use the ExpandCluster function to recursively visit all neighbor point clouds in the Cth cluster, and retain all neighbor point clouds whose number of new neighbor point clouds found with each neighbor point cloud as the cluster center is greater than p and add them to the Cth cluster;

[0018] Step 2.4: After assigning i+1 to i, return to step 1.2 and execute sequentially until i>n, thereby obtaining C clusters, and each cluster is used as the complete point cloud of a single cable;

[0019] Step 2.5: Sort the C-root cables according to the minimum coordinate value in the x-axis direction in the complete point cloud of each cable to obtain sorted C-root cables.

[0020] Furthermore, the step 3 comprises the following steps:

[0021] Step 3.1: Use a cubic polynomial to fit the complete point cloud of a single cable to obtain the approximate center line of the single cable, thereby determining the tangent vector of the single cable at any position, and use a slicing method to divide the complete point cloud of the single cable into S micro-segments;

[0022] Step 3.2: Randomly select three points from the denoised point cloud on the cross section of the sth micro-segment for circle fitting, obtain a fitting circle, and count whether the number of points in the fitting circle that meet the fitting requirements is greater than the threshold K, where: If yes, then the corresponding fitting circle is taken as the approximate center of the point cloud on the cross section of the sth micro-segment With approximate radius ; Otherwise, return to step 3.2 to reselect points;

[0023] Step 3.3: Set a radius threshold , calculate the distance from any point in the point cloud on the cross section of the sth micro-segment to the approximate center of the circle The distance d will satisfy The points are retained, and the rest are regarded as noise points and removed, thus obtaining the remaining point cloud on the cross section of the sth micro-segment;

[0024] Step 3.4: Set a threshold for the number of points , if the number of points in the remaining point cloud is greater than the threshold , the fitting circle of the corresponding micro-segment is taken as the candidate circle model, otherwise, return to step 3.2 to reselect points; until the number of candidate circle models reaches the set upper limit;

[0025] Step 3.5: Set the threshold , the least squares method is used to calculate the center and radius of the point cloud in any candidate circle model , and calculate the distance from any point in any candidate circle model to the center of its own fitting circle , and will satisfy The points are retained, and the rest are regarded as noise points and removed, thus obtaining the remaining point cloud in any candidate circle model;

[0026] Step 3.6: Count the number of remaining point clouds in each candidate circle model. The candidate circle model with the largest number of remaining point clouds is the optimal circle model of the point cloud on the cross section of the sth micro-segment. The center and radius corresponding to the optimal circle model are the fitting center and fitting radius of the point cloud on the cross section of the sth micro-segment, thereby obtaining the fitting center and fitting radius of the point cloud on the cross section of S micro-segments.

[0027] Furthermore, the step 5 comprises the following steps:

[0028] Step 5.1: Take the upper end point of a single cable as the coordinate origin O(0,0), the upper end point pointing to the lower end point in the vertical direction as the positive direction of the Y axis, and the upper end point pointing to the lower end point in the horizontal direction as the positive direction of the X axis, establish a two-dimensional local coordinate system for the single cable, and mark the coordinates of the lower end point of the single cable as B(l,h); l represents the horizontal span of the cable, and h represents the vertical span of the cable; mark the coordinates of the S fitting circle centers in the two-dimensional local coordinate system as ,in, represents the coordinates of the center of the s-th fitting circle in the two-dimensional local coordinate system;

[0029] Step 5.2: Set the calculation interval of the horizontal component of the cable force ,in, is the lower limit of the calculation interval of the horizontal component of the cable force, is the upper limit of the calculation range of the horizontal component of the cable force;

[0030] Step 5.3: Initialize q=1 and set the total number of calculations to Q; ;

[0031] Step 5.4: Use equation (1) to calculate the qth calculated value of the horizontal component of the cable force :

[0032] (1)

[0033] Step 5.5: Use formula (2) to calculate the qth ordinate value of a single cable :

[0034] (2)

[0035] In formula (2), represents the abscissa of the center of the sth fitting circle in the local coordinate system, c represents the linear density of a single cable, cosh is the hyperbolic cosine function, and are the two calculation coefficients for the qth time, and we have:

[0036] (3)

[0037] (4)

[0038] In formula (4), sinh is the hyperbolic sine function;

[0039] Step 5.6: Use formula (5) to get the sum of squares of the difference calculated for the qth time: ;

[0040] (5)

[0041] Step 5.7: After assigning q+1 to q, return to step 5.4 and recalculate until q>Q, and record the calculated value of the horizontal component of the cable force corresponding to the minimum sum of squares of the difference as ;

[0042] Step 5.8: Initialize q = 1 and update the upper limit of the calculation interval of the horizontal component of the cable force to , the lower limit is , and use formula (6) to update the qth calculated value Then, follow the process from step 5.5 to step 5.7 to obtain the calculated value of the horizontal component of the updated cable force. ;

[0043] (6)

[0044] In formula (6), m represents a multiple;

[0045] Step 5.9: Initialize q = 1 and update the upper limit of the calculation interval of the horizontal component of the cable force to , the lower limit is , and use formula (7) to update the qth calculated value Then, follow the process from step 5.5 to step 5.7 to obtain the final calculated value of the horizontal component of the cable force. , and the calculated value of the horizontal component of the final cable force The corresponding two calculation coefficients are recorded as and ;

[0046] (7)

[0047] Step 5.10: Calculate the cable force F at any position of the cable using equation (8);

[0048] (8)

[0049] In formula (8), represents the angle between the cable and the horizontal plane, and is obtained by equation (9);

[0050] (9).

[0051] An electronic device of the present invention includes a memory and a processor, wherein the memory is used to store a program that supports the processor to execute the method for calculating the cable force of an inclined cable based on three-dimensional scanning cable shape, and the processor is configured to execute the program stored in the memory.

[0052] The present invention provides a computer-readable storage medium, wherein a computer program is stored on the computer-readable storage medium, and the computer program, when executed by a processor, executes the steps of the method for calculating the cable force of a stay cable based on three-dimensional scanning of the cable shape.

[0053] Compared with the prior art, the present invention has the following beneficial effects:

[0054] 1. The present invention proposes a method for calculating the cable tension of a cable-stayed bridge based on laser scanning, which can quickly and accurately identify the cable tension of a cable-stayed bridge. Compared with the traditional cable tension test method, the accuracy of the cable tension calculation of the present invention is only related to the weight of the cable and the extraction of the cable shape accuracy, and is not affected by the coupling of multiple parameters of the cable itself, which greatly improves the accuracy of the cable tension test. At the same time, compared with the traditional cable tension test, it has been well verified in actual bridges in terms of data collection efficiency, avoiding potential risks, reducing traffic interference, and improving the accuracy of cable tension testing.

[0055] 2. Compared with the existing contour cable segmentation algorithm, which requires the input of multiple parameters, and some parameters are difficult to determine the exact value, the DBSCAN clustering algorithm adopted in the present invention only needs to input the cluster radius and the minimum number of clusters, and these two parameters are very easy to determine, making the cable segmentation method simpler and more convenient, and the result accuracy is higher. For the existing cable shape extraction method, the use of the improved RANSAC algorithm can not only improve the efficiency of removing noise points, but also dynamically adjust the number of calculations according to the effect of fitting the center of the circle, simplifying the cable shape extraction steps, reducing the workload, and improving the calculation efficiency. A key advantage of the improved RANSAC algorithm is that it has strong robustness to outliers (outliers) in the data. Even if there are many noise points and outliers in the scanned point cloud data, it can find a reasonable fitting model, thereby improving the accuracy of the fitting, ensuring the accuracy of the cable shape extraction, and making the cable force calculation more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 It is a specific flow chart of the method of the present invention;

[0057] Figure 2 This is a schematic diagram of the original cable point cloud of 3D scanning;

[0058] Figure 3 It is a schematic diagram of the point cloud of a single cable in three-dimensional coordinates;

[0059] Figure 4a It is a schematic diagram of segmenting the cable point cloud using the DBSCAN clustering algorithm of the present invention;

[0060] Figure 4b A schematic diagram of the accuracy of cable point cloud segmentation using the DBSCAN clustering algorithm;

[0061] Figure 5a It is a schematic diagram of the cross-section projection of the cable point cloud;

[0062] Figure 5b This is a schematic diagram of using the improved RANSAC algorithm to remove noise points;

[0063] Figure 5c This is a comparison chart of the center of the fitted circle before and after noise reduction;

[0064] Figure 5d Schematic diagram for extracting the shape of the cable;

[0065] Figure 6 Schematic diagram for comparison between calculated cable force and actual cable force. DETAILED DESCRIPTION

[0066] In this example, a method for calculating the cable force based on 3D scanning cable shape mainly includes: 1. Obtaining the original point cloud of the cable based on the 3D scanner, and using the DBSCAN clustering algorithm to segment the scanned cable point cloud, so as to quickly and accurately obtain each independent cable point cloud; 2. Accurately extracting the cable shape; 3. According to the cable shape extracted in the above steps, calculating the cable force by the catenary formula. Specifically, Figure 1 As shown, the method is performed in the following steps:

[0067] Step 1: Use a 3D laser scanner to obtain the original point cloud of multiple cables. The original point cloud image of the cables is as follows: Figure 2 As shown. A global Cartesian coordinate system is established to transform the original point cloud of multiple cables into the global coordinate system. The schematic diagram of the point cloud of a single cable in three-dimensional coordinates is shown in Figure 3 The coordinates of the point cloud data are shown as ,in, is the coordinate of the i-th 3D point cloud, , n is the total number of 3D point clouds of the cable, represents the coordinate of the i-th 3D point cloud in the x-axis direction, represents the coordinate of the i-th point in the y-axis direction, Represents the coordinate of the i-th point in the z-axis direction;

[0068] The x-axis coordinate and the coordinates in the z-axis direction The 2D coordinates that make up the i-th 3D point cloud , thus forming two-dimensional point cloud coordinate data .

[0069] Step 2: Use DBSCAN clustering algorithm to Segmentation is performed to obtain a complete point cloud of each cable;

[0070] Step 2.1: Define the minimum cluster radius as, the minimum number of point clouds within the fitting radius is p=10; the size of the minimum cluster radius is defined by the shortest horizontal distance between the two cables. The cluster count is C, and initialize C=0; i=1.

[0071] Step 2.2: As the cluster center, use the RegionQuery function to find The cluster radius All point cloud data in Neighbor point cloud, judge Is the total number of neighbor point clouds of the Cth cluster less than p? If so, mark the neighbor point clouds in the Cth cluster as noise points and execute step 1.4; otherwise, assign C+1 to C and The neighbor point clouds of form the Cth cluster and execute step 1.3.

[0072] Step 2.3: Use the ExpandCluster function to recursively visit all neighbor point clouds in the Cth cluster, and retain all neighbor point clouds whose number of new neighbor point clouds found with each neighbor point cloud as the cluster center is greater than p and add them to the Cth cluster;

[0073] Step 2.4: After assigning i+1 to i, return to step 1.2 and execute sequentially until i>n, thereby obtaining C clusters, and taking each cluster as the complete point cloud of a single cable; the cable segmentation image is as follows Figure 4a As shown, each color represents a separate cable point cloud; the segmentation accuracy picture is as follows Figure 4b As shown, it can be observed that the number of automatically segmented cable point clouds is exactly the same as that of manual segmentation.

[0074] Step 2.5: Sort the C-root cables according to the minimum coordinate value in the x-axis direction in the complete point cloud of each cable to obtain sorted C-root cables.

[0075] Step 3: Use the improved RANSAC algorithm to reduce the noise of the cross-sectional point cloud of the cable to obtain the reduced-noise cross-sectional point cloud of the cable;

[0076] Step 3.1: Use a cubic polynomial to fit the complete point cloud of a single cable to obtain the approximate center line of the single cable, thereby determining the tangent vector of the single cable at any position; and use slicing to divide the complete point cloud of the single cable into S micro-segments. The number of micro-segments S is related to the length of the cable, and generally 0.5m to 1m is taken as the length of a micro-segment;

[0077] Step 3.2: Select three points from the point cloud on the cross section of the sth micro-segment to perform circle fitting and obtain a fitting circle, where: The cross-sectional projection of the cable is shown in Figure 5a As shown. Calculate the center and radius of the fitting circle formed by the three sample points, calculate the distance from the point to the center of the fitting circle for each remaining sample point, and compare it with the preset threshold to determine whether the point is an inner point. If the distance is less than the set radius threshold, the point is marked as an inner point and retained, otherwise it is marked as an outer point and removed. Count whether the number of points in the fitting circle that meet the fitting requirements is greater than the threshold K. The number of threshold K is generally taken as three quarters of the total number of fitting points. If so, the corresponding fitting circle is used as the approximate center of the point cloud on the cross section of the sth micro-segment. With approximate radius ; Otherwise, return to step 3.2 to reselect points.

[0078] Step 3.3: Set a radius threshold = 0.01m, calculate the distance from any point in the point cloud on the cross section of the sth micro-segment to the approximate center of the circle The distance d will satisfy The points are retained, and the rest are regarded as noise points and removed, thus obtaining the remaining point cloud on the cross section of the sth micro-segment;

[0079] Step 3.4: Set a point cloud number threshold , The value of is two-thirds of the total number of fitting sample points. If the number of points in the remaining point cloud is greater than the threshold , the fitting circle of the corresponding micro-segment is the candidate circle model, otherwise, return to step 3.2 to reselect points; until the number of candidate circle models reaches the set upper limit; the improved RANSAC algorithm separates the noise point image as shown in Figure 5b As shown, the red points are removed external points, i.e., noise points; the blue points are retained internal points, which are used to fit the center and radius of the circle.

[0080] Step 3.5: Set the threshold =0.008m, the least square method is used to find the center and radius of any candidate circle model. Fit and calculate the distance from any point cloud in any candidate circle model to its own center , and will satisfy The points are retained, and the rest are regarded as noise points and removed, thus obtaining the remaining point cloud in any candidate circle model;

[0081] Step 3.6: Count the number of remaining point clouds in each candidate circle model. The candidate circle model with the largest number of remaining point clouds is the best circle model of the point cloud on the cross section of the sth micro-segment. The center and radius corresponding to the best circle model are the fitting center and fitting radius of the point cloud on the cross section of the sth micro-segment, thereby obtaining the fitting center and fitting radius of the point cloud on the cross section of S micro-segments. The comparison of the center of the circle of the two fittings before and after denoising is shown in the figure below. Figure 5c As shown, the red circle is the fitted circle after the first denoising, and the blue circle is the final fitted circle.

[0082] Step 4: Connect the S fitting circles in order to obtain the shape of a single cable. Figure 5d As shown;

[0083] Step 5.1: Take the upper end point of a single cable as the coordinate origin O(0,0), the upper end point pointing to the lower end point in the vertical direction as the positive direction of the Y axis, and the upper end point pointing to the lower end point in the horizontal direction as the positive direction of the X axis, establish a two-dimensional local coordinate system for the single cable, and mark the coordinates of the lower end point of the single cable as B(l,h); l represents the horizontal span of the cable, and h represents the vertical span of the cable; mark the coordinates of the S fitting circle centers in the two-dimensional local coordinate system as ,in, represents the coordinates of the center of the s-th fitting circle in the two-dimensional local coordinate system;

[0084] Step 5.2: Set the calculation interval of the horizontal component of the cable force ,in, is the lower limit of the calculation interval of the horizontal component of the cable force, It is the upper limit of the calculation range of the horizontal component of the cable force; the calculation range of the horizontal component of the cable force is based on the empirical value of the cable force of the actual bridge.

[0085] Step 5.3: Initialize q=1 and set the total number of calculations to Q; ; The value of Q is related to the upper and lower limits of the calculation interval of the horizontal component of the cable force;

[0086] Step 5.4: Use equation (1) to calculate the qth calculated value of the horizontal component of the cable force :

[0087] (1)

[0088] Step 5.5: Use formula (2) to calculate the qth ordinate value of a single cable :

[0089] (2)

[0090] In formula (2), represents the abscissa of the center of the sth fitting circle in the local coordinate system, c represents the linear density of a single cable, cosh is the hyperbolic cosine function, and are the two calculation coefficients for the qth time, and we have:

[0091] (3)

[0092] (4)

[0093] In formula (4), sinh is the hyperbolic sine function.

[0094] Step 5.6: Use formula (5) to get the sum of squares of the difference calculated for the qth time: ;

[0095] (5)

[0096] Step 5.7: After assigning q+1 to q, return to step 5.4 and recalculate until q>Q, and record the calculated value of the horizontal component of the cable force corresponding to the minimum sum of squares of the difference as ;

[0097] Step 5.8: Initialize q = 1 and update the upper limit of the calculation interval of the horizontal component of the cable force to , the lower limit is , and use formula (6) to update the qth calculated value Then, follow the process from step 5.5 to step 5.7 to obtain the calculated value of the horizontal component of the updated cable force. ;

[0098] (6)

[0099] In formula (6), m represents a multiple;

[0100] Step 5.9: Initialize q = 1 and update the upper limit of the calculation interval of the horizontal component of the cable force to , the lower limit is , the value of m is 1 / 1000 of the calculation interval length. And use formula (7) to update the qth calculation value Then, follow the process from step 5.5 to step 5.7 to obtain the final calculated value of the horizontal component of the cable force. , and the calculated value of the horizontal component of the final cable force The corresponding two calculation coefficients are recorded as and ;

[0101] (7)

[0102] Step 5.10: Use equation (8) to calculate the cable force F at any position of the cable. Compare the calculated cable force with the actual cable force. Figure 6 As shown in the figure, the error between the calculated cable force and the designed cable force is basically kept within 5%;

[0103] (8)

[0104] In formula (8), represents the angle between the cable and the horizontal plane, and is obtained by equation (9);

[0105] (9).

[0106] In this embodiment, an electronic device includes a memory and a processor, wherein the memory is used to store a program that supports the processor to execute the above method, and the processor is configured to execute the program stored in the memory.

[0107] In this embodiment, a computer-readable storage medium stores a computer program on the computer-readable storage medium, and the computer program executes the steps of the above method when executed by a processor.

Claims

1. A method for calculating the cable force of a stay cable based on three-dimensional scanning of the cable shape, characterized in that: The steps include: Step 1: Use a 3D laser scanner to obtain the original point cloud of multiple cables and transform it into a global Cartesian coordinate system to obtain a coordinate set of the 3D point cloud. ,in, is the coordinate of the i-th 3D point cloud, n is the total number of 3D point clouds of all cables, represents the coordinate of the i-th 3D point cloud in the x-axis direction, represents the coordinate of the i-th point in the y-axis direction, Represents the coordinate of the i-th point in the z-axis direction; The x-axis coordinate and the coordinates in the z-axis direction The 2D coordinates that make up the i-th 3D point cloud , thus forming two-dimensional point cloud coordinate data ; Step 2: Use DBSCAN clustering algorithm to Segmentation is performed to obtain a complete point cloud of each cable; Step 3: Use the improved RANSAC algorithm to reduce the noise of the cross-sectional point cloud of each micro-segment on a single cable, and obtain the cross-sectional point cloud of each micro-segment on a single cable after noise reduction, and use it to fit the optimal circle model of the point cloud on the cross-sectional area of ​​each micro-segment and its fitting center and fitting radius; Step 4: Connect the centers of each fitting circle in sequence to obtain the shape of a single cable; Step 5: Calculate the cable force F of a single cable based on its shape.

2. The method for calculating the cable force of a stay cable based on three-dimensional scanning of the cable shape according to claim 1 is characterized in that: The step 2 comprises the following steps: Step 2.1: Define the minimum clustering radius as , the minimum number of point clouds within the fitting radius is p; the current number of clusters is C, and C=0 is initialized; i=1; Step 2.2: As the cluster center, use the RegionQuery function to find The cluster radius All point cloud data in Neighbor point cloud, judge Is the total number of neighbor point clouds of less than p? If so, mark the neighbor point clouds in the Cth cluster as noise points and execute step 2.4; Otherwise, after assigning C+1 to C, The neighbor point clouds of form the Cth cluster and execute step 2.3; Step 2.3: Use the ExpandCluster function to recursively visit all neighbor point clouds in the Cth cluster, and retain all neighbor point clouds whose number of new neighbor point clouds found with each neighbor point cloud as the cluster center is greater than p and add them to the Cth cluster; Step 2.4: After assigning i+1 to i, return to step 1.2 and execute sequentially until i>n, thereby obtaining C clusters, and each cluster is used as the complete point cloud of a single cable; Step 2.5: Sort the C-root cables according to the minimum coordinate value in the x-axis direction in the complete point cloud of each cable to obtain sorted C-root cables.

3. The method for calculating the cable force of a stay cable based on three-dimensional scanning of the cable shape according to claim 2 is characterized in that: The step 3 comprises the following steps: Step 3.1: Use a cubic polynomial to fit the complete point cloud of a single cable to obtain the approximate center line of the single cable, thereby determining the tangent vector of the single cable at any position, and use a slicing method to divide the complete point cloud of the single cable into S micro-segments; Step 3.2: Randomly select three points from the denoised point cloud on the cross section of the sth micro-segment for circle fitting, obtain a fitting circle, and count whether the number of points in the fitting circle that meet the fitting requirements is greater than the threshold K, where: If yes, then the corresponding fitting circle is taken as the approximate center of the point cloud on the cross section of the sth micro-segment With approximate radius ; Otherwise, return to step 3.2 to reselect points; Step 3.3: Set a radius threshold , calculate the distance from any point in the point cloud on the cross section of the sth micro-segment to the approximate center of the circle The distance d will satisfy The points are retained, and the rest are regarded as noise points and removed, thus obtaining the remaining point cloud on the cross section of the sth micro-segment; Step 3.4: Set a threshold for the number of points , if the number of points in the remaining point cloud is greater than the threshold , the fitting circle of the corresponding micro-segment is taken as the candidate circle model, otherwise, return to step 3.2 to reselect points; until the number of candidate circle models reaches the set upper limit; Step 3.5: Set the threshold , the least squares method is used to calculate the center and radius of the point cloud in any candidate circle model , and calculate the distance from any point in any candidate circle model to the center of its own fitting circle , and will satisfy The points are retained, and the rest are regarded as noise points and removed, thus obtaining the remaining point cloud in any candidate circle model; Step 3.6: Count the number of remaining point clouds in each candidate circle model. The candidate circle model with the largest number of remaining point clouds is the optimal circle model of the point cloud on the cross section of the sth micro-segment. The center and radius corresponding to the optimal circle model are the fitting center and fitting radius of the point cloud on the cross section of the sth micro-segment, thereby obtaining the fitting center and fitting radius of the point cloud on the cross section of S micro-segments.

4. The method for calculating the cable force of a stay cable based on three-dimensional scanning of the cable shape according to claim 3 is characterized in that: The step 5 comprises the following steps: Step 5.1: Take the upper end point of a single cable as the coordinate origin O(0,0), the upper end point pointing to the lower end point in the vertical direction as the positive direction of the Y axis, and the upper end point pointing to the lower end point in the horizontal direction as the positive direction of the X axis, establish a two-dimensional local coordinate system for the single cable, and mark the coordinates of the lower end point of the single cable as B(l,h); l represents the horizontal span of the cable, and h represents the vertical span of the cable; mark the coordinates of the S fitting circle centers in the two-dimensional local coordinate system as ,in, represents the coordinates of the center of the s-th fitting circle in the two-dimensional local coordinate system; Step 5.2: Set the calculation interval of the horizontal component of the cable force ,in, is the lower limit of the calculation interval of the horizontal component of the cable force, is the upper limit of the calculation range of the horizontal component of the cable force; Step 5.3: Initialize q=1 and set the total number of calculations to Q; ; Step 5.4: Use equation (1) to calculate the qth calculated value of the horizontal component of the cable force : (1) Step 5.5: Use formula (2) to calculate the qth ordinate value of a single cable : (2) In formula (2), represents the abscissa of the center of the sth fitting circle in the local coordinate system, c represents the linear density of a single cable, cosh is the hyperbolic cosine function, and are the two calculation coefficients for the qth time, and we have: (3) (4) In formula (4), sinh is the hyperbolic sine function; Step 5.6: Use formula (5) to get the sum of squares of the difference calculated for the qth time: ; (5) Step 5.7: After assigning q+1 to q, return to step 5.4 and recalculate until q>Q, and record the calculated value of the horizontal component of the cable force corresponding to the minimum sum of squares of the difference as ; Step 5.8: Initialize q = 1 and update the upper limit of the calculation interval of the horizontal component of the cable force to , the lower limit is , and use formula (6) to update the qth calculated value Then, follow the process from step 5.5 to step 5.7 to obtain the calculated value of the horizontal component of the updated cable force. ; (6) In formula (6), m represents a multiple; Step 5.9: Initialize q = 1 and update the upper limit of the calculation interval of the horizontal component of the cable force to , the lower limit is , and use formula (7) to update the qth calculated value Then, follow the process from step 5.5 to step 5.7 to obtain the final calculated value of the horizontal component of the cable force. , and the calculated value of the horizontal component of the final cable force is The corresponding two calculation coefficients are recorded as and ; (7) Step 5.10: Calculate the cable force F at any position of the cable using equation (8); (8) In formula (8), represents the angle between the cable and the horizontal plane, and is obtained by equation (9); (9)。 5. An electronic device, comprising a memory and a processor, characterized in that: The memory is used to store a program that supports the processor to execute the method for calculating the cable force of the inclined cable based on three-dimensional scanning cable shape as described in any one of claims 1-4, and the processor is configured to execute the program stored in the memory.

6. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method for calculating the cable force of a stay cable based on three-dimensional scanning of the cable shape described in any one of claims 1 to 4 are executed.

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