A calculation method and device for the call height of a transmission tower based on the segmentation position

Abstract

The present invention discloses a calculation method and device for the height of a transmission tower based on the segmentation position in the technical field of transmission towers. The method includes: determining the segmentation position of the transmission tower according to the obtained point cloud of the transmission tower; calculating the shape parameters of the segmentation position of the transmission tower, identifying the key segmentation position of the transmission tower, performing image processing on the point cloud above the key segmentation position of the transmission tower, determining the tower type, and obtaining the position of the lowest cross arm of the transmission tower; calculating the height of the transmission tower according to the position of the lowest cross arm of the transmission tower and the position of the lowest point of the transmission tower. The present invention can quickly and efficiently obtain the height of the tower without the need for on-site tower-by-tower measurement, improves the accuracy and automation degree of calculating the height of the tower, reduces the field workload of technical personnel, shortens the production cycle, and greatly reduces the production cost of survey and design.

Description

Technical Field

[0001] The present invention belongs to the technical field of transmission towers, and particularly relates to a method and device for calculating the calling height of a transmission tower based on the segmentation position. Background Art

[0002] At present, the transmission line is an important part of the power system, and ensuring its safe, efficient and reliable operation is related to the stable development of the country. With the development of social economy, the demand for electric energy is increasing. The existing lines have been affected by factors such as line aging, low load capacity, and cross-span transformation, and can no longer meet the needs of production development, so the existing lines need to be renovated and upgraded. The tower is a steel-frame structure and is the core component of the transmission line, and its types are complex and diverse. The calling height of the tower, also known as the nominal height or marked height, refers to the vertical distance from the lowest cross-arm to the bottom plate of the longest leg or the top surface of the foundation. The calling height of the tower is the most important data information in the transmission line and is also an essential measurement data in the process of renovating and upgrading the existing lines. The calling height of the tower is generally obtained by using a total station to assist high-precision GNSS, and it is often necessary to go to the site to measure each tower on the spot, which is time-consuming and laborious, and the measurement efficiency is low. Summary of the Invention

[0003] To solve the deficiencies in the prior art, the present invention provides a method and device for calculating the calling height of a transmission tower based on the segmentation position, which improves the accuracy and automation degree of calculating the calling height of the tower and reduces the field work amount of technical personnel.

[0004] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0005] In the first aspect, a method for calculating the calling height of a transmission tower based on the segmentation position is provided, including: determining the segmentation position of the transmission tower according to the obtained point cloud of the transmission tower; calculating the shape parameters of the segmentation position of the transmission tower, identifying the key segmentation position of the transmission tower, performing image processing on the point cloud above the key segmentation position of the transmission tower, determining the tower type, and obtaining the position of the lowest cross-arm of the transmission tower; calculating the calling height of the transmission tower according to the position of the lowest cross-arm of the transmission tower and the position of the lowest point of the transmission tower.

[0006] Further, the determining the segmentation position of the transmission tower according to the obtained point cloud of the transmission tower includes: redirecting the point cloud of the transmission tower; obtaining the local maximum density position of the point cloud of the transmission tower according to the redirected point cloud of the transmission tower; calculating the filling rate of the local maximum density position, so as to determine the segmentation position of the transmission tower.

[0007] Further, obtaining the local maximum density position of the transmission tower point cloud based on the redirected transmission tower point cloud includes: stratifying the redirected transmission tower point cloud along the Z-axis with a certain width h, and counting the number of points in each layer; setting a sliding window with a width of W and moving it from bottom to top. If the density value at the middle position of the window is the maximum density value within the entire window, calculate the average value of the Z coordinates of all points in the middle layer of the window, and locate it as the local maximum density position.

[0008] Further, the density value is defined as the number of points in each layer of the transmission tower point cloud.

[0009] Further, the calculation method of the filling rate is: dividing the point cloud of each layer of the transmission tower into grids along the Y-axis with a certain width d, and the ratio of the number of grids with points to the total number of grids is the filling rate. If the filling rate is greater than the threshold T f , calculate the average value of the Z coordinates of all points located in this layer, which is the segmentation position.

[0010] Further, the ideal value of h is the thickness of the point cloud at the segmentation position, ranging from 0.03 - 0.25 m. W is the width of the sliding window, and its value should be less than twice the minimum difference in height between adjacent segmentation positions. The parameter d is used to calculate the filling rate, and the interval between adjacent points on the Y-axis ranges from 0.01 - 0.3 m. T f is set to 75%.

[0011] Further, calculate the shape parameter of the segmentation position of the transmission tower through the following formula:

[0012]

[0013] where G represents the shape parameter of the segmentation position of the transmission tower, and the shape parameters of each segmentation position of the transmission tower from bottom to top are Gi, i = 1, 2, 3 ···; L X' and L Y' respectively represent the maximum lengths of the point cloud projections of each layer onto the X' and Y' axes.

[0014] Further, identify the key segmentation positions of the transmission tower, perform image processing on the point cloud above the key segmentation positions of the transmission tower, determine the tower type, and obtain the position of the lowest cross-arm of the transmission tower, including: if the shape parameters of the segmentation positions of the transmission tower are all greater than the first threshold, then the transmission tower is an M-type tower, and the key segmentation position of the M-type tower is the segmentation position corresponding to the maximum shape parameter value, and the position of the lowest cross-arm is the key segmentation position; if the shape parameters of the segmentation positions of the transmission tower do not satisfy being all greater than the first threshold, then the transmission tower is a non-M-type tower, and set the second threshold T G as the sum of the shape parameter G1 of the lowest segmentation position of the transmission tower and the error constant Ce, and compare the shape parameters G of each segmentation position from bottom to topi and the second threshold T G , if it is greater than the second threshold, the key segmentation position of the transmission tower is G i-1 The corresponding segmentation position; project the point cloud above the key segmentation position of the non-M type transmission tower onto the YZ plane, perform image processing, and determine whether the type of the transmission tower is T type or O type. If it is a T type tower, the position of the lowest cross arm is the segmentation position adjacent to and above the key segmentation position. If it is an O type tower, the position of the lowest cross arm is the local maximum density position above the key segmentation position where the filling rate is greater than T f `, and T f ` is set to 50%.

[0015] Furthermore, the method for determining whether the type of the transmission tower is T type or O type is as follows: after binarizing the projected point cloud, smooth the image based on the morphological gradient operation, perform morphological closing operation on the local holes existing in the image, finally extract the contour according to the image contour extraction algorithm, sort the extracted contours according to the number of pixels contained in the contour, and calculate the ratio of the previous one to the next one in turn. If the maximum ratio appears in the first position, it is a T type tower; otherwise, it is an O type tower.

[0016] In a second aspect, a device for calculating the height of a transmission tower based on the segmentation position is provided, including: a segmentation position determination module for determining the segmentation position of the transmission tower according to the obtained point cloud of the transmission tower; a data processing module for calculating the shape parameters of the segmentation position of the transmission tower, identifying the key segmentation position of the transmission tower, performing image processing on the point cloud above the key segmentation position of the transmission tower, determining the tower type, and obtaining the position of the lowest cross arm of the transmission tower; a height calculation module for calculating the height of the transmission tower according to the position of the lowest cross arm of the transmission tower and the lowest point position of the transmission tower.

[0017] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0018] (1) By determining the segmentation position of the transmission tower according to the obtained point cloud of the transmission tower; calculating the shape parameters of the segmentation position of the transmission tower, identifying the key segmentation position of the transmission tower, performing image processing on the point cloud above the key segmentation position of the transmission tower, determining the tower type, and obtaining the position of the lowest cross arm of the transmission tower; calculating the height of the transmission tower according to the position of the lowest cross arm of the transmission tower and the lowest point position of the transmission tower, the present invention can quickly and efficiently obtain the height of the tower without the need for on-site tower-by-tower measurement, improve the accuracy and automation degree of calculating the height of the tower, reduce the field workload of technicians, shorten the production cycle, and greatly reduce the production cost of survey and design;

[0019] (2) The present invention can make full use of LiDAR data, which can improve the digital level of survey and design. Description of the Drawings

[0020] Figure 1 It is a schematic diagram of the overall process of a method for calculating the height of a transmission tower based on the segmentation position provided by an embodiment of the present invention;

[0021] Figure 2 It is a schematic diagram of the process for determining the tower segmentation position based on the point density and filling rate in an embodiment of the present invention;

[0022] Figure 3 It is a schematic diagram of the process for identifying the key segmentation position based on the shape parameters, using an image processing method to distinguish between T-shaped towers and O-shaped towers, and determining the position of the lowest cross arm in an embodiment of the present invention;

[0023] Figure 4 It is a schematic diagram of calculating the filling rate in an embodiment of the present invention;

[0024] Figure 5 It is a result diagram of identifying the tower segmentation position in an embodiment of the present invention. Among them, (a) is the projection of the T-shaped tower on the YZ plane, (b) is the projection of the O-shaped tower on the YZ plane, (c) is the projection of the M-shaped tower on the YZ plane, where s i is the segmentation position, i = 1, 2, 3 ···, s k is the key segmentation position;

[0025] Figure 6 It is a schematic diagram of calculating the tower height in an embodiment of the present invention. Among them, (a)(d)(g) are schematic diagrams of calculating the height of the T-shaped tower, (b)(e)(h) are schematic diagrams of calculating the height of the O-shaped tower, (c)(f)(i) are schematic diagrams of calculating the height of the M-shaped tower, s l is the position of the lowest cross arm, s low is the lowest point position. Detailed Embodiment

[0026] The present invention will be further described below with reference to the drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention and should not be used to limit the protection scope of the present invention.

[0027] Embodiment 1:

[0028] As Figures 1 to 6As shown in the figure, a method for calculating the height of a transmission tower based on the segmentation position includes: determining the segmentation position of the transmission tower according to the obtained point cloud of the transmission tower; calculating the shape parameters of the segmentation position of the transmission tower, identifying the key segmentation positions of the transmission tower, performing image processing on the point cloud above the key segmentation positions of the transmission tower to determine the tower type, and obtaining the position of the lowest cross-arm of the transmission tower; calculating the height of the transmission tower according to the position of the lowest cross-arm of the transmission tower and the position of the lowest point of the transmission tower.

[0029] S1. Determine the segmentation position of the transmission tower according to the obtained point cloud of the transmission tower. In this embodiment, an airborne lidar (Airborne Light Detection And Ranging, LiDAR) is used to obtain the point cloud of the transmission tower; as an active remote sensing technology, airborne lidar can directly and quickly obtain high-precision and dense three-dimensional point clouds, and is not restricted by light and terrain. The LiDAR system is carried on a fixed-wing or helicopter platform, flies above the transmission corridor to obtain point cloud data, and through data processing, objective and accurate structured information of the transmission corridor is obtained, providing data support for the upgrade and transformation of the transmission line.

[0030] As Figure 2 shown, step S1 specifically includes:

[0031] S11. Redirect the point cloud of the transmission tower to obtain the redirected point cloud of the transmission tower;

[0032] S12. Count the number of points in each layer of the transmission tower to obtain the local maximum density position of the point cloud of the transmission tower;

[0033] S13. Calculate the filling rate of the local maximum density position to determine the segmentation position of the transmission tower.

[0034] The method for obtaining the local maximum density position is specifically:

[0035] S121. Divide the point cloud of the transmission tower into layers along the Z-axis with a certain width h, and count the number of points in each layer;

[0036] S122. Set a sliding window with a width of W and move it from bottom to top. If the density value at the middle position of the window (the density value is the number of points in each layer of the point cloud of the transmission tower) is the maximum density value within the entire window, calculate the average value of the Z coordinates of all points in the middle layer of the window, which is defined as the local maximum density position.

[0037] The method for calculating the filling rate is specifically:

[0038] The layered point cloud is divided into grids along the Y-axis with a certain width d. The ratio of the number of grids with points to the total number of grids is the filling rate. If the filling rate is greater than the threshold T f, the average value of the Z coordinates of all points in this layer is calculated, which is the segmentation position.

[0039] Among them, the ideal value of h is the thickness of the point cloud at the segmentation position, and the range is 0.03 - 0.25 m. After a large number of data tests in this embodiment, 0.2 m is set as the default value, and the segmentation position error is less than 5 cm. W is the width of the sliding window, and its value should be less than twice the minimum difference in height between adjacent segmentation positions. 2 m is set as the default value. The parameter d is used to calculate the filling rate. The interval between adjacent points on the Y-axis ranges from 0.01 - 0.3 m. To avoid the filling rate from becoming smaller due to the lack of point cloud at the segmentation position, the larger value of 0.3 m is taken. T f The ideal value of is 100%, but due to occlusion or incomplete scanning, etc., there are usually missing point clouds. After multiple experimental tests, 75% is set as the default value.

[0040] S2. Calculate the shape parameters of the segmentation position of the transmission tower, identify the key segmentation positions of the transmission tower, perform image processing on the point cloud above the key segmentation positions of the transmission tower, determine the tower type, and obtain the position of the lowest cross arm of the transmission tower.

[0041] As Figure 3 shown, step S2 specifically includes:

[0042] S21. Calculate the shape parameters of the segmentation position of the transmission tower:

[0043]

[0044] Among them, G represents the shape parameter of the segmentation position of the transmission tower, and the shape parameters of each segmentation position of the transmission tower from bottom to top are Gi, i = 1, 2, 3 ···; L X' and L Y' respectively represent the maximum lengths of the point clouds of each layer projected onto the X' and Y' axes.

[0045] S22. Determine the key segmentation positions of the tower and the M-type tower according to the shape parameter G. If all the calculated shape parameters are greater than 1.5 (the first threshold), then the type of the transmission tower is the M-type tower, and the key segmentation position of the M-type tower is the segmentation position corresponding to the maximum G value; otherwise, the type of the transmission tower cannot be determined yet and may be a T-type or O-type tower. Set the shape parameter threshold T G (the second threshold) as the sum of G1 (the shape parameter of the lowest segmentation position of the transmission tower) and the error constant Ce, and compare the shape parameters Gi of each segmentation position layer from bottom to top with the threshold T G , if it is greater than the threshold T G , then the key segmentation position of the transmission tower (T-type or O-type tower) is the segmentation position corresponding to G i-1 .

[0046] Among them, the shape parameter threshold T G and Ce are used to identify the key segmentation positions. After a large number of experimental tests, Ce is set to 0.5.

[0047] S23. Distinguish between T-shaped and O-shaped towers and determine the position of the lowest crossarm. Project the point cloud above the key segmentation position of the poles and towers except for the M-shaped tower onto the YZ plane, perform image processing, and use ratio calculation to determine whether the pole and tower is T-shaped or O-shaped. At this time, the three tower types have been determined. If it is a T-shaped tower, the position of the lowest crossarm is the segmentation position adjacent above the key segmentation position; if it is an M-shaped tower, the position of the lowest crossarm is the key segmentation position; if it is an O-shaped tower, the position of the lowest crossarm does not correspond to the segmentation position, but is the position of the local maximum density where the filling rate above the adjacent segmentation position is greater than T f ’.

[0048] Among them, after multiple experimental tests, 50% is set as the default value of T f ’.

[0049] The specific determination of the pole and tower type is as follows:

[0050] After binarizing the projected point cloud, smooth the image based on morphological gradient operation. For the local holes existing in the image, perform morphological closing operation, and finally extract the contour according to the image contour extraction algorithm. Sort the extracted contours according to the number of pixels contained in the contour (from large to small), and calculate the ratio of the previous one to the next one in turn. If the maximum ratio appears in the first position, it is a T-shaped tower; otherwise, it is an O-shaped tower.

[0051] Among them, the number of pixels in the true contour is much more than that in the false contour. The position of the maximum ratio of the T-shaped tower is 1, and the position of the maximum ratio of the O-shaped tower is 2.

[0052] S3. Calculate the height above ground of the transmission pole and tower according to the position of the lowest crossarm of the transmission pole and tower and the position of the lowest point of the transmission pole and tower.

[0053] Step S2 specifically includes:

[0054] S31. Obtain the position of the lowest point of the transmission pole and tower. Sort the point cloud of the transmission pole and tower according to the Z coordinate, take the point cloud with the lowest 30 points, and calculate the average value of the Z coordinates, which is the position of the lowest point of the pole and tower;

[0055] S32. Calculate the height above ground of the pole and tower. Subtract the position of the lowest point of the pole and tower from the position of the lowest crossarm of the pole and tower to obtain the height above ground of the pole and tower.

[0056] On the one hand, without the need for on-site tower-by-tower measurement, the present invention can quickly and efficiently obtain the call height of the pole tower, improve the accuracy and automation level of calculating the call height of the pole tower, reduce the field work load of technicians, shorten the production cycle, and greatly reduce the production cost of survey and design. On the other hand, the present invention can make full use of laser LiDAR data and improve the digital level of survey and design.

[0057] Embodiment 2:

[0058] Based on the method for calculating the call height of a transmission pole tower based on the segmentation position described in Embodiment 1, this embodiment provides a device for calculating the call height of a transmission pole tower based on the segmentation position, including: a segmentation position determination module for determining the segmentation position of the transmission pole tower according to the obtained point cloud of the transmission pole tower; a data processing module for calculating the shape parameters of the segmentation position of the transmission pole tower, identifying the key segmentation positions of the transmission pole tower, performing image processing on the point cloud above the key segmentation positions of the transmission pole tower, determining the tower type, and obtaining the position of the lowest cross arm of the transmission pole tower; a call height calculation module for calculating the call height of the transmission pole tower according to the position of the lowest cross arm of the transmission pole tower and the position of the lowest point of the transmission pole tower.

[0059] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and deformations can be made, and these improvements and deformations should also be regarded as the protection scope of the present invention.

Claims

1. A calculation method for the call height of a transmission tower based on the segmentation position, characterized in that, Including: Determine the segmentation position of the transmission tower according to the acquired point cloud of the transmission tower; Calculate the shape parameters of the segmentation position of the transmission tower, identify the key segmentation position of the transmission tower, perform image processing on the point cloud above the key segmentation position of the transmission tower, determine the tower type, and obtain the position of the lowest cross arm of the transmission tower; Calculate the height of the transmission tower according to the position of the lowest cross arm of the transmission tower and the lowest point position of the transmission tower; Among them, identifying the key segmentation position of the transmission tower, performing image processing on the point cloud above the key segmentation position of the transmission tower, determining the tower type, and obtaining the position of the lowest cross arm of the transmission tower includes: If the shape parameters of the segmentation position of the transmission tower are all greater than the first threshold, the transmission tower is an M-type tower. The key segmentation position of the M-type tower is the segmentation position corresponding to the maximum shape parameter value, and the position of the lowest cross arm is the key segmentation position; If the shape parameters of the segmentation positions of the transmission tower do not all satisfy being greater than the first threshold, the transmission tower is a non-M type tower, and a second threshold T G is set as the sum of the shape parameter G1 of the lowermost segmentation position of the transmission tower and the error constant Ce, and the shape parameters G of each segmentation position are compared from bottom to top i with the second threshold T G . If it is greater than the second threshold, the critical segmentation position of the transmission tower is the segmentation position corresponding to G i-1 . Project the point cloud above the critical segmentation position of the non-M type transmission tower onto the YZ plane, perform image processing, and determine whether the type of the transmission tower is T type or O type. If it is a T type tower, the lowermost cross-arm position is the segmentation position adjacent above the critical segmentation position. If it is an O type tower, the lowermost cross-arm position is the local maximum density position where the filling rate is greater than T f ` and T f ` is set to 50%; The value of the error constant Ce is 0.5; Calculate the shape parameters of the segmentation position of the transmission tower through the following formula: ， Among them, is the shape parameter representing the segmentation position of the transmission tower. The shape parameters of each segmentation position of the transmission tower from bottom to top are Gi, where i = 1, 2, 3...; L X' and L Y' respectively represent the maximum lengths of the projected point clouds of each layer onto the X' and Y' axes.

2. The calculation method of the call height of a transmission tower based on the segmentation position according to claim 1, characterized in that The step of determining the segmentation position of the transmission tower according to the acquired point cloud of the transmission tower includes: Redirect the point cloud of the transmission tower; Obtain the local maximum density position of the point cloud of the transmission tower according to the redirected point cloud of the transmission tower; Calculate the filling rate of the local maximum density position, thereby determining the segmentation position of the transmission tower.

3. The calculation method of the calling height of a transmission tower based on the segmentation position according to claim 2, wherein The step of obtaining the local maximum density position of the point cloud of the transmission tower according to the redirected point cloud of the transmission tower includes: Layer the redirected point cloud of the transmission tower along the Z-axis with a certain width h, and count the number of points in each layer; Set a sliding window with a width of W and move it from bottom to top. If the density value at the middle position of the window is the maximum density value within the entire window, calculate the average value of the Z coordinates of all points in the middle layer of the window and locate it as the local maximum density position.

4. The calculation method of the height of a transmission tower based on the splitting position according to claim 3, characterized in that, The density value is defined as the number of points in each layer of the point cloud of the transmission tower.

5. The calculation method of the height of a transmission tower based on the splitting position according to claim 3, characterized in that, The calculation method of the filling rate is: Divide the point cloud of each layer of the transmission tower into grids along the Y-axis with a certain width d. The ratio of the number of grids with points to the total number of grids is the filling rate. If the filling rate is greater than the threshold T f , calculate the average value of the Z coordinates of all points located in this layer, which is the segmentation position.

6. The calculation method of the transmission tower call height based on the segmentation position according to claim 5, characterized in that The ideal value of h is the thickness of the point cloud at the segmentation position, ranging from 0.03 to 0.25 m. W is the width of the sliding window, and its value should be less than twice the minimum difference in height between adjacent segmentation positions. The parameter d is used to calculate the filling rate, and the interval between adjacent points on the Y-axis ranges from 0.01 to 0.3 m, T f is set to 75%.

7. The calculation method of the call height of a transmission tower based on the segmentation position according to claim 1, wherein The method for determining whether the type of the transmission tower is a T-type or an O-type is: after binarizing the projected point cloud, smooth the image based on the morphological gradient operation. For the local holes existing in the image, perform morphological closing operation. Finally, extract the contour according to the image contour extraction algorithm, sort the extracted contours according to the number of pixels contained in the contour, and calculate the ratio of the previous one to the next one in turn. If the maximum ratio appears in the first position, it is a T-type tower; otherwise, it is an O-type tower.

8. A calculation device for the call height of a transmission tower based on the splitting position, characterized in that, Including: A segmentation position determination module for determining the segmentation position of the transmission tower according to the acquired point cloud of the transmission tower; A data processing module for calculating the shape parameters of the segmentation position of the transmission tower, identifying the key segmentation position of the transmission tower, performing image processing on the point cloud above the key segmentation position of the transmission tower, determining the tower type, and obtaining the position of the lowest cross arm of the transmission tower; A height calculation module for calculating the height of the transmission tower according to the position of the lowest cross arm of the transmission tower and the lowest point position of the transmission tower; Among them, the key segmentation positions of the transmission tower are identified, image processing is performed on the point cloud above the key segmentation positions of the transmission tower to determine the tower type, and the position of the lowest cross arm of the transmission tower is obtained, including: If the shape parameters of the segmentation positions of the transmission tower are all greater than the first threshold, the transmission tower is an M-type tower. The key segmentation position of the M-type tower is the segmentation position corresponding to the maximum shape parameter value, and the position of the lowest cross arm is the key segmentation position; If the shape parameters of the segmentation positions of the transmission tower do not all satisfy being greater than the first threshold, the transmission tower is a non-M type tower, and a second threshold T is set. G It is the sum of the shape parameter G1 of the lowermost segmentation position of the transmission tower and the error constant Ce. Compare the shape parameters G of each segmentation position from bottom to top. i with the second threshold T G , if it is greater than the second threshold, the key segmentation position of the transmission tower is G i-1 The corresponding segmentation position; project the point cloud above the key segmentation position of the non-M type transmission tower onto the YZ plane, perform image processing, and determine whether the type of the transmission tower is T type or O type. If it is a T type tower, the lowermost cross-arm position is the segmentation position adjacent above the key segmentation position. If it is an O type tower, the lowermost cross-arm position is the local maximum density position where the filling rate above the key segmentation position is greater than T f `, and T f ` is set to 50%; The value of the error constant Ce is 0.5; The shape parameters of the segmentation positions of the transmission tower are calculated by the following formula: ， Among them, is the shape parameter indicating the segmentation position of the transmission tower. The shape parameters of each segmentation position of the transmission tower from bottom to top are Gi, where i = 1, 2, 3, ···; L X' and L Y' respectively represent the maximum lengths of the projected point clouds of each layer onto the X' and Y' axes.

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