Method and device for extracting tower footing cross-section diagram from point cloud data and storage medium

Abstract

The invention discloses a method for extracting a tower footing cross-section diagram through point cloud data. The method comprises the following steps that S1, line selection is conducted to determine tower coordinates; s2, extracting and classifying a ground point layer from the laser point cloud data acquired by aerial survey; s3, determining a tower footing measurement range and a tower footing measurement direction according to requirements, automatically cutting the point cloud ground layer, further generating a tower footing point cloud pattern spot combination, and extracting point cloud coordinates on each direction line of each tower footing tower leg in batches from the point cloud ground layer according to a specified point interval; s4, presetting an optimization standard value, and optimally selecting point cloud coordinates according to a simplest optimization algorithm; s5, drawing tower footing section diagrams in batches by adopting tower footing section drawing software; and S6, checking the distance value in the tower leg direction and the number of tower legs for the drawn tower footing cross-section diagram according to a preset measurement result standard. According to the method, the simplest optimization algorithm is adopted to optimize and select the coordinates on each direction line of the tower leg, so that the subsequent data processing amount can be reduced, and the cross-section diagram generation quality is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of engineering surveying and mapping, and in particular to a method, a device and a storage medium for extracting a tower foundation cross-section diagram using point cloud data. Background Art

[0002] The tower base cross-section diagram refers to the result of cross-section measurement centered on the center pile of the tower, radiating 8 to 25 meters in the four leg directions or in eight directions (four leg directions and four auxiliary directions). The tower base cross-section diagram is an important reference data for structural professionals in designing tower base slope protection, configuring slopes, high and low legs, retaining walls, drainage ditches, etc.

[0003] When surveying and designing transmission lines above 35kV at home and abroad, tower foundation section measurement is required. In recent years, the commonly used practice for tower foundation section measurement is to use GNSS receivers and total stations to measure the tower foundation in the field and then use related tower foundation software to generate tower foundation data files, so as to facilitate the use of drawing software such as CASS or ArcGIS to generate tower foundation section diagrams.

[0004] At present, the production technology of tower foundation section is mainly divided into the following two types: One is the DEM method to produce tower foundation cross-section diagrams: it mainly uses DEM and DOM to generate a virtual 3D large scene for indoor line selection to determine the tower coordinates, and then uses the existing DEM to extract the coordinate points of the tower legs in 4 or 8 directions of each tower within the specified tower foundation range, and then uses the relevant tower foundation software to generate SCR and other tower foundation coordinate files, and uses CASS or ArcGIS and other software to draw the map; One is the manual full-field measurement production method: mainly using designers to directly specify the tower base position in the field, and field surveyors use GNSS equipment and total stations to collect tower base cross-sections in the field according to the tower coordinates or the specified tower base position, and then generate tower base coordinate files based on the collected tower base data files, and then use CASS or ArcGIS and other software to draw the map.

[0005] However, in actual use, the existing tower foundation section production technology has the following shortcomings: (1) Transmission line towers are usually erected on hills or high mountains. For the existing manual full-field measurement method, technicians need to clear the trees and shrubs on the tower leg direction channel in addition to the fixed-point measurement, which easily consumes a lot of manpower and material resources, and the measurement efficiency is not high; (2) When using the DEM information extracted from existing aerial triangulation results to draw cross sections, the vegetation coverage problem cannot be solved. The DEM generated by aerial triangulation of aerial images is not a real DEM, but a manually modified DSM. The image data can never see the bottom of the vegetation, and all DEM elevation data are manually estimated. Therefore, the tower base cross section generated in this way cannot be actually used in densely vegetated areas; (3) When the UAV is equipped with LiDAR aerial survey technology to obtain DEM, although the point cloud data collected by the LiDAR can be used to generate a DEM with actual elevation data, this method will lose a lot of terrain details and steep slopes in the process of generating DEM, which is inconsistent with the actual terrain and easily leads to the construction unit being unable to carry out the tower foundation construction according to the tower foundation cross-section drawing.

[0006] In addition, since some detailed feature points will be lost in the sampling process of generating DEM, the accuracy of DEM is reduced compared with point cloud data, and the accuracy of the tower base cross-section diagram generated using DEM will also be reduced accordingly.

[0007] To this end, this application specifically proposes a method for extracting a tower foundation cross-section diagram from point cloud data to solve the above technical problems. Summary of the invention

[0008] The main purpose of the present invention is to provide a method for extracting a tower foundation cross-section diagram using point cloud data, which replaces manual field measurement or the method of using DEM generation, greatly improves the operating efficiency, greatly reduces the field workload, reduces the survey cost, and improves the accuracy of the survey data, so as to solve the technical problems raised in the background technology.

[0009] The present invention adopts the following technical solutions to solve the above technical problems: A method for extracting a tower foundation cross-section diagram from point cloud data comprises the following steps: S1. Select the line and determine the tower coordinates; S2. extract and classify the point cloud ground layer from the laser point cloud data collected by aerial survey; S3. Determine the tower foundation measurement range and tower foundation measurement direction according to the requirements, and automatically cut the point cloud ground layer according to the selected tower foundation measurement range, generate the tower foundation point cloud ground layer with the specified tower foundation measurement range and the tower foundation leg direction line centered on the coordinates of each tower as the tower foundation point cloud pattern combination, and then batch extract the point cloud coordinates on each direction line of each tower foundation leg from the tower foundation point cloud ground layer according to the specified point spacing; S4. Preset the optimization standard value, and optimize the point cloud coordinates on all the tower base and tower legs in each direction according to the simplest optimization algorithm to eliminate redundant point cloud coordinates including point cloud coordinates with large point cloud elevation deviation values; S5. Based on the optimized tower base tower leg coordinate file, use the tower base section drawing software to batch draw the tower base section drawing; S6. Check the distance value and the number of tower legs in the direction of the tower legs according to the preset measurement results standard for the drawn tower foundation cross-section.

[0010] Preferably, the specific operation process of step S1 includes: Using digital orthophotos DOM, digital elevation models DEM, digital surface models DSM, digital line drawings DLG and laser point cloud data, three-dimensional line selection and pole arrangement of transmission lines are carried out in accordance with preset transmission line design specifications to determine the line path and the coordinates of the center points of each tower. Preferably, the specific operation process of the S2 step includes: according to the terrain characteristics and vegetation density including mountainous areas, plains, and urban areas, and the geographical conditions including gully areas, laser point cloud data processing software is used to extract and classify the point cloud layer corresponding to the ground points from the laser point cloud raw data collected by aerial survey, and export it as a point cloud ground layer.

[0011] Preferably, the simplest optimization algorithm in step S3 includes: L1. Extract the lowest point of each tower base in the direction of the tower leg, and then connect it into a multi-segment line from the center pile of the tower base to the lowest point and then to the last point; L2. Calculate the elevation deviation of the point cloud in the middle of the polyline, find the point with the largest elevation deviation from each polyline, connect them end to end to form a new polyline connection; L3. Iterate the L2 step until the elevation deviation of the point cloud on each polyline is less than 0.2 meters, and the iteration terminates; L4. Each node on the multi-segment line has useful point cloud coordinates as the tower leg direction, and other points are removed.

[0012] On the other hand, the present invention further discloses a computer-readable storage medium storing a computer program, wherein when the computer program is executed by a processor, the processor executes the steps of the above method.

[0013] On the other hand, the present invention further discloses a computer device, including a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the above method.

[0014] It can be seen from the above technical solution that the present invention provides a method for extracting a tower foundation cross-section diagram from point cloud data. Compared with the prior art, the present invention has the following advantages: 1. The present invention automatically extracts tower foundation section measurement points based on radar point cloud data, replacing manual field measurement production or extraction from DEM. The extraction from point cloud data is more refined, the extraction accuracy is higher, the data accuracy is higher, and a large amount of field measurement costs can be saved.

[0015] 2. The present invention adopts the simplest optimization algorithm to optimize the coordinates on the lines of the tower legs in all directions, eliminates a large number of redundant points while retaining the key nodes and steep slopes and cliffs, and generates a more concise and accurate cross-sectional view of the tower base. It can reduce the data processing volume for subsequent end view generation and automatic quality inspection of cross-sectional views, improve the cross-sectional generation speed and automatic inspection speed, and reduce large data point cloud errors, thereby improving the quality of cross-sectional view generation.

[0016] 3. The present invention can automatically draw tower foundation cross-section diagrams in batches and conduct quality inspections based on the extracted tower foundation cross-section point coordinates, which saves manpower and improves inspection efficiency.

[0017] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present invention, nor is it intended to limit the scope of the present invention. Other features of the present invention will become easy to understand through the following description. Of course, it is not necessary to achieve all of the advantages described above simultaneously for any product implementing the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings: Figure 1 It is a schematic diagram of the overall process of the present invention; Figure 2 This is an example diagram of the point cloud display of a single tower base and tower leg direction of the present invention; Figure 3 Automatically draw an example diagram for the tower foundation section of the present invention; Figure 4 This is an example diagram of the tower foundation cross-section inspection result of the present invention. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. In the absence of conflict, the embodiments in this application and the features in the embodiments can be combined with each other. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0020] In the embodiment, see Figures 1 to 4 .

[0021] like Figure 1 As shown, the method for extracting a tower foundation cross-section diagram from point cloud data proposed in an embodiment of the present invention comprises the following steps: S1. The designer selects the line and determines the tower coordinates; Designers use digital orthophotos DOM, digital elevation models DEM, digital surface models DSM, digital line drawings DLG or laser point cloud data to perform three-dimensional line selection and pole arrangement according to the transmission line design specifications, thereby determining the line path and the coordinates of the center points of each tower; S2. Extract and classify ground point layers from the laser point cloud data collected by aerial survey; Use designated laser point cloud data processing software (such as LiDAR360, TerraSolid, etc.) to extract and classify the point cloud layer of ground points from the original laser point cloud data collected by aerial survey, and export it as the point cloud ground layer; When classifying and extracting ground points from laser point cloud data, various appropriate point cloud extraction algorithms should be used according to different terrain features such as mountainous areas, plains, urban areas, vegetation density, gully areas, etc.; At this point, it should be noted that the tower foundation section measurement points are automatically extracted based on radar point cloud data, instead of manual field measurement or extraction from DEM. Compared with point cloud data, the extraction is more precise, the extraction accuracy is higher, the data accuracy is higher, and a lot of field measurement costs can be saved. In addition, it should be noted that the point cloud density of the current mainstream laser radar scanning measurement in China is 36-100 points / square meter, which means that one tower base section measurement point can be extracted at about 0.1 to 0.2 meters. Manual field measurements generally have one measurement point every 3 to 5 meters, and higher-precision DEMs generally have one measurement point every 1 or 5 meters. In addition, the DEM is generated after triangulation smoothing, and data accuracy is seriously lost. All important data such as steep slopes or cliffs are also easily lost, which will have a significant impact on the accuracy of the tower base section. Therefore, the automatic extraction of tower base section measurement points from radar point cloud data has higher accuracy and refinement, and can save a lot of field measurement costs compared to field measurements.

[0022] S3. Figure 2 As shown, according to the tower design requirements of transmission lines of different voltage levels and different tower types, angles, etc., the tower base measurement range and tower base measurement direction requirements are determined, and then the point cloud ground layer is automatically cut according to the measurement range of each tower base, and the tower base point cloud ground layer of the specified tower base measurement range and the tower base leg direction line centered on the coordinates of each tower is generated as a tower base point cloud pattern combination with a certain distance range (such as a square of 30*30 meters or 50*50 meters) centered on the center point of the tower position, and then the point cloud coordinates of each tower base leg on each direction line are batch extracted from the tower base point cloud ground layer with high precision according to the specified point spacing (such as 0.2m point spacing); It should be noted that the tower base measurement range here is generally determined according to the voltage level of the transmission line. The 35kV transmission line is generally 20*20 meters, the 110kV~220kV transmission line is generally 30*30 meters, the 500kV line is generally 40*40 meters, and the 800kV and 1000kV and above are generally 50*50 meters or larger; S4. Optimize and select the point cloud coordinates on all the tower base and tower legs in all directions according to the simplest optimization algorithm, while retaining the key nodes and steep slope and cliff information, a large number of redundant points are eliminated, and the tower base cross-section can be generated concisely and accurately; Since there are generally many point cloud coordinates on the lines of the tower base and tower legs in various directions extracted from the ground layer of the tower base point cloud, and when the point cloud density is high, it may reach more than 100 point cloud coordinates, so it is necessary to optimize the selection; At this time, the simplest optimization algorithm is: first extract the lowest point in the direction of each tower base and tower leg, then connect a polyline from the center pile of the tower base to the lowest point and then to the last point, and then calculate the elevation and distance deviation values ​​of the point cloud in the middle of the polyline, find the point with the largest elevation deviation from each polyline, connect the end to the end to form a new polyline again, and iterate the calculation continuously until the elevation deviation value of the point cloud on each polyline is less than 0.2 meters. The iteration is terminated, and each node on the polyline is the useful point cloud coordinate in the direction of the tower leg, which is retained, and other points are eliminated; At this time, the number of point clouds is optimized through the simplest optimization algorithm, which can not only reduce the data processing volume for subsequent end face drawing generation and cross-section drawing automatic quality inspection, improve the cross-section generation speed and automatic inspection speed, but also reduce large data point cloud errors and improve the quality of cross-section drawing generation; S5. Automatically draw tower foundation cross-sections in batches; According to the optimized tower base and tower leg coordinate file, use tower base section drawing software or CASS plug-in to generate tower base section file (such as SCR file), and then use CASS or ArcGIS software to automatically draw tower base section diagram. The section diagram after drawing can be referred to Figure 3 ; S6. Automatic quality inspection of tower foundation section; The software is used to conduct relevant quality inspections on the automatically drawn tower foundation section diagram according to the measurement results standards. At this time, the software is used to automatically conduct quality inspections on the tower foundation section diagram, which not only saves manpower but also improves inspection efficiency; Since the tower foundation of transmission lines with voltage levels of 220kV and above is generally measured and drawn according to 8 tower leg direction lines, and the tower foundation of transmission lines with voltage levels of 35kV to 110kV is generally measured and drawn according to 4 tower leg direction lines, the main inspection is whether the distance value in the tower leg direction meets the design requirements and whether the number of tower legs is 4 or 8. The result of the automatic inspection of the tower foundation is the final product. If it fails, it needs to be manually inspected and modified. The inspection results can be referred to Figure 4 .

[0023] In summary, based on the method of the present application, the present invention further discloses a system for extracting a tower foundation cross-section diagram from point cloud data, wherein the system internally stores a corresponding logic module and an input module, wherein: Input module, used to input corresponding parameters and data to be processed; The logic module is used to execute the method of extracting the tower foundation cross-section diagram from the point cloud data based on preset parameters and the data to be processed.

[0024] The system can determine the directions of four tower legs or eight tower leg direction lines according to the tower type and rotation angle selected by the designer. After the designer selects the positions and coordinates of all towers, the system can complete the extraction, drawing and automatic inspection of the tower base cross-section drawings of all towers with one click, greatly improving the efficiency of transmission line survey and design work.

[0025] In a specific embodiment, for 10 medium and large transmission line projects that have been surveyed, the traditional measured tower foundation cross-sections of these lines were collected, and then the tower foundation cross-sections were automatically generated from the radar point cloud data of these lines using this method. Finally, manual superposition elevation comparison inspection and tower foundation point cloud extraction rate, tower foundation integrity and compliance inspection were carried out. The inspection results are shown in the following table:

[0026] After manual verification, inspection and comparison, 97% to 99% of the tower base elevation differences in the tower base cross-section drawings of 10 transmission lines are between 0.1 and 0.3 m. The accuracy of the data results meets the requirements of the survey specifications, with an accuracy rate of >97%. The tower base cross-section drawings extracted and drawn by the software are accurate and reliable.

[0027] On the other hand, the present invention further discloses a computer-readable storage medium storing a computer program, wherein when the computer program is executed by a processor, the processor executes the steps of the above method.

[0028] On the other hand, the present invention further discloses a computer device, including a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the above method.

[0029] In another embodiment provided by the present application, a computer program product including instructions is also provided, which, when executed on a computer, enables the computer to execute the method for extracting a tower foundation cross-section diagram from point cloud data in any of the above embodiments.

[0030] It is understandable that the system provided by the embodiment of the present invention corresponds to the method provided by the embodiment of the present invention, and the explanation, examples and beneficial effects of the relevant contents can refer to the corresponding parts in the above method.

[0031] The embodiment of the present application also provides an electronic device, including a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory communicate with each other through the communication bus. Memory, used to store computer programs; The processor is used to implement the method of extracting the tower foundation cross-section diagram from the point cloud data when executing the program stored in the memory.

[0032] The communication bus mentioned in the above electronic device may be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. The communication bus may be divided into an address bus, a data bus, a control bus, etc.

[0033] The communication interface is used for communication between the above electronic device and other devices.

[0034] The memory may include a random access memory (RAM) or a non-volatile memory (NVM), such as at least one disk memory. Optionally, the memory may also be at least one storage device located away from the aforementioned processor.

[0035] The above-mentioned processor can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it can also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, and discrete hardware components.

[0036] It should also be noted that electronic devices also include terminal devices, which can also be called terminals, user equipment (UE), mobile stations (MS), mobile terminals (MT), etc. Terminal devices can be mobile phones, smart TVs, wearable devices, tablet computers (Pad), computers with wireless transceiver functions, virtual reality (VR) terminal devices, augmented reality (AR) terminal devices, wireless terminals in industrial control, wireless terminals in self-driving, wireless terminals in remote medical surgery, wireless terminals in smart grids, wireless terminals in transportation safety, wireless terminals in smart cities, wireless terminals in smart homes, etc. The embodiments of the present application do not limit the specific technology and specific device form adopted by the terminal devices.

[0037] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions may be transmitted from one website site, computer, server or data center to another website site, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium may be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more available media integrated. The available medium may be a magnetic medium (e.g., a floppy disk, a hard disk, a tape), an optical medium, or a semiconductor medium (e.g., a solid-state drive Solid State Disk), etc.

[0038] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

[0039] In addition, it should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back...), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0040] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the meaning of "and / or" appearing in the full text includes three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or schemes that A and B meet at the same time. In addition, in the embodiments of the present invention, "multiple" refers to more than two. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in the field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

Claims

1. A method for extracting a tower foundation cross-section diagram from point cloud data, characterized in that: The following steps are involved: S1. Select the line and determine the tower coordinates; S2. Collect, extract and classify the ground layer of the point cloud; S3. Determine the measurement range and direction of the tower foundation, cut the ground layer of the point cloud, generate a combination of point cloud spots as the tower foundation, and then batch extract the point cloud coordinates of each tower foundation leg in each direction line; S4. Optimize and select the point cloud coordinates on all the tower base and tower legs in each direction according to the simplest optimization algorithm to eliminate redundant point cloud coordinates; S5. Use tower foundation section drawing software to batch draw tower foundation section drawings; S6. Check the distance value in the tower leg direction and the number of tower legs.

2. The method for extracting a tower foundation cross-section diagram from point cloud data according to claim 1, characterized in that: The specific operation process of step S1 includes: Using digital orthophotos DOM, digital elevation models DEM, digital surface models DSM, digital line drawings DLG and laser point cloud data, three-dimensional line selection and pole arrangement of transmission lines are carried out in accordance with preset transmission line design specifications to determine the line path and the coordinates of the center points of each tower.

3. The method for extracting a tower foundation cross-section diagram from point cloud data according to claim 1, characterized in that: The specific operation process of the S2 step includes: according to the terrain characteristics and vegetation density including mountainous areas, plains, and urban areas, and the geographical conditions including gully areas, laser point cloud data processing software is used to extract and classify the point cloud layer corresponding to the ground points from the laser point cloud raw data collected by aerial survey, and export it as a point cloud ground layer.

4. The method for extracting a tower foundation cross-section diagram from point cloud data according to claim 1, characterized in that: The simplest optimization algorithm in step S3 includes: L1. Extract the lowest point of each tower base in the direction of the tower leg, and then connect it into a multi-segment line from the center pile of the tower base to the lowest point and then to the last point; L2. Calculate the elevation deviation of the point cloud in the middle of the polyline, find the point with the largest elevation deviation from each polyline, connect them end to end to form a new polyline connection; L3. Iterate the L2 step until the elevation deviation of the point cloud on each polyline is less than 0.2 meters, and the iteration terminates; L4. Each node on the multi-segment line has useful point cloud coordinates as the tower leg direction, and other points are removed.

5. A computer-readable storage medium, characterized in that: A computer program is stored, and when the computer program is executed by a processor, the processor is caused to execute the steps of the method according to any one of claims 1 to 4.

6. A computer device, characterized in that: The method comprises a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the method according to any one of claims 1 to 4.

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