High-precision earthwork measuring and calculating method and system for constructing three-dimensional model based on aerial survey of unmanned aerial vehicle

Abstract

The invention discloses a high-precision earthwork measurement and calculation method and system for constructing a three-dimensional model based on aerial survey of an unmanned aerial vehicle. The method comprises the steps that image control points and check points are arranged in a to-be-measured area in advance; starting to collect aerial survey image data of the unmanned aerial vehicle, and performing supplementary measurement on an obstacle shielding area to obtain supplementary measurement data; importing the aerial survey image data to generate a live-action three-dimensional model; and finding an image control point identification position on the three-dimensional model, performing corresponding point pricking on the image control point identification position and an actually measured image control point, performing conversion from longitude and latitude coordinates of the model to project coordinates after all the image control points are matched, regenerating the three-dimensional model, importing check point coordinate data, and checking the precision of the model. Seed points are added to remove obstacles to restore the surface topography, then drawings and design elevations are imported to carry out earthwork high-precision calculation, the problems that manual calculation combined with other software is complex in operation and prone to making mistakes and consumes a large amount of time are solved, accurate data support is provided for earthwork construction, and the project construction period is shortened.

Description

Technical Field

[0001] The present invention relates to the field of engineering construction technology, and in particular to a high-precision earthwork measurement method and system based on unmanned aerial vehicle (UAV) aerial survey to construct a three-dimensional model. Background Art

[0002] With the acceleration of urbanization and the development of infrastructure construction, earthwork projects occupy an important position in various construction projects. Earthwork projects not only involve land leveling and excavation, but also involve multiple links such as filling and transportation. It is one of the basic work to ensure the smooth progress of engineering projects. Although traditional earthwork quantity calculation methods, such as the cross-section method, the square grid method, the contour method and the digital elevation model (DEM) method, have met the engineering needs to a certain extent, they have many limitations in efficiency and accuracy.

[0003] At present, the existing earthwork calculation methods in China mainly include the cross-section method, the square grid method, the contour method and the DEM method. Among them, the DEM method estimates the earthwork volume by constructing a digital terrain model. Compared with other methods, its accuracy is higher, but it is still difficult to meet the needs of real-time feedback and verification of the earthwork volume at the construction site during the construction phase. In recent years, with the rapid development of drone technology, the use of drones for oblique photogrammetry has become an emerging technical means. This method not only improves work efficiency and reduces labor costs, but also can obtain high-density, full-coverage measurement data under complex terrain conditions, providing a solid foundation for subsequent three-dimensional modeling.

[0004] Among them, the error of earthwork volume calculated by traditional earthwork calculation method is large, the contour method requires a large amount of data storage and the data structure is complex, which is often difficult to establish. Although the DEM method can overcome the problem of redundant data in areas with small terrain undulations and has higher accuracy than other methods, it is still difficult to meet the requirements of the construction stage and cannot timely feedback and verify the earthwork volume of the construction site, which is not conducive to the control of construction period and construction cost. When the existing UAV aerial survey technology faces lush vegetation, dense buildings or water coverage, there are obstacles such as trees and houses on the surface, resulting in a certain deviation between the established three-dimensional model and the actual surface, which has a great impact on the subsequent earthwork calculation. In addition, when dealing with complex terrain, traditional methods are difficult to accurately fit the surface, especially when large areas of vegetation or water are removed, which is easy to cause large errors in earthwork calculation. These problems limit the promotion and use of existing technologies in practical applications. There is an urgent need for a new solution to overcome these defects in order to achieve more accurate and efficient earthwork volume measurement. Summary of the invention

[0005] In view of the above defects or improvement needs of the prior art, the purpose of the present invention is to provide a high-precision earthwork measurement algorithm and system based on drone aerial survey to build a three-dimensional model; this method is constructed on the BIM Twins platform by combining drone aerial survey technology with terrain supplementary survey using multiple measurement methods, and converts the model's longitude and latitude coordinates to project coordinates based on the preset image control point identification positions and the actual measured image control points to construct a high-precision three-dimensional model. Based on this three-dimensional model, the construction plan is imported, the earthwork volume is calculated directly by the cross-section method, and an earthwork report can be generated, which solves the problem that manual calculation operations combined with other software are complex, error-prone and time-consuming, and provides accurate data support for earthwork construction and saves project construction period.

[0006] To achieve this purpose, according to one aspect of the present invention, a high-precision earthwork measurement algorithm based on drone aerial survey to build a three-dimensional model is provided, comprising:

[0007] S100, pre-arrange image control points and check points in the area to be measured; start collecting drone aerial survey image data, and conduct supplementary surveys on the area blocked by obstacles to obtain supplementary survey data;

[0008] S200, importing the aerial survey image data to generate a real-scene three-dimensional model;

[0009] S300, finding the image control point identification position on the three-dimensional model and matching it with the actual measured image control points, converting the model longitude and latitude coordinates to project coordinates after all image control points are matched, regenerating the three-dimensional model, and importing the checkpoint coordinate data to verify the model accuracy.

[0010] S400, importing the supplementary survey data, combining the three-dimensional coordinate data with the original model using surface fitting technology, completing terrain fitting, and generating a digital surface model;

[0011] S500: extracting information, designing elevations, and calculating earthwork based on the digital surface model.

[0012] Furthermore, the image control point measurement mainly verifies the "GPS RTK" through GPS coordinate system parameter conversion and correction methods, and uses the GPS control point acquisition function to collect the three-dimensional coordinate data of the image control points. The acquisition time each time must not be less than 60 seconds. After multiple acquisitions, the average is taken and saved for future use.

[0013] Furthermore, the other methods of supplementary surveying the obstacle-blocked area include: for general obstacle areas, three-dimensional coordinate data collection by total station; for areas with low plants on the ground, three-dimensional coordinate data collection by GPS; for large water surface areas, data collection by unmanned water surveying vessels.

[0014] Furthermore, step S200 includes: importing image data with RTK information collected by the drone, checking the integrity and availability of the data, setting various parameters, and the software automatically matching feature points and performing aerial triangulation operations to obtain a point cloud composed of points with the same name, and then performing dense matching of multi-view images, using points with the same name to build a model, and then connecting the point clouds to build a three-dimensional grid, and finally performing texture mapping on the model to produce a three-dimensional model.

[0015] Furthermore, the conversion of the model longitude and latitude coordinates to the project coordinates in step S300 includes: assuming that the seven parameters are three translation parameters (DX, DY, DZ), three rotation angles (RX, RY, RZ) and a scale factor S; the original model image control point coordinates (X, Y, Z) are known, and the actual project coordinates are (X1, Y1, Z1), and the calculation formula can be listed as follows:

[0016] X1=S*(X-RZ*Y+RY*Z)+DX

[0017] Y1=S*(RZ*X+Y-RX*Z)+DX

[0018] Z1=S*(-RY*X+RX*Y+Z)+DZ

[0019] Wherein, RX represents the angle of rotation about the X-axis; RY represents the angle of rotation about the Y-axis; RZ represents the angle of rotation about the Z-axis; DX represents the amount of translation in the X-axis direction; DY represents the amount of translation in the Y-axis direction; and DZ represents the amount of translation in the Z-axis direction.

[0020] Furthermore, it includes: the seven parameter values ​​can be solved by bringing in at least three groups of coordinate data, and bringing in the seven parameters can realize the conversion from model coordinates to project coordinates.

[0021] Furthermore, step S500 includes: importing the construction plan, automatically generating the current surface cross-section diagram, combining it with the design section, calculating the excavation and filling area of ​​each section, obtaining the earthwork volume between the two sections, combining it with the section within the red line, and summarizing the total amount of excavation and filling within the red line.

[0022] According to a second aspect of the present invention, a high-precision earthwork measurement system for building a three-dimensional model based on drone aerial survey is provided, comprising: a first module for pre-arranging image control points and checkpoints in the area to be measured, starting drone aerial survey data collection, and supplementing the area blocked by obstacles; based on the BIM Twins platform, importing the aerial survey image data to generate a real-scene three-dimensional model;

[0023] The second module is used to find the image control point identification position on the three-dimensional model and match it with the actual measured image control points. After matching all the image control points, the model longitude and latitude coordinates are converted to project coordinates, the three-dimensional model is regenerated, and the checkpoint coordinate data is imported to verify the model accuracy.

[0024] The third module is used to import the supplementary survey data, combine the three-dimensional coordinate data with the original model using surface fitting technology, complete terrain fitting, and generate a digital surface model;

[0025] The fourth module is used to extract information, design elevation and calculate earthwork based on the digital surface model.

[0026] According to a third aspect of the present invention, there is provided a computer device comprising a processor, a memory, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, any step of the high-precision earthwork measurement algorithm for constructing a three-dimensional model based on drone aerial survey is implemented.

[0027] According to a fourth aspect of the present invention, there is provided a computer-readable storage medium storing a computer program; when the computer program is executed by a processor, any step of the high-precision earthwork measurement algorithm for constructing a three-dimensional model based on drone aerial survey is implemented.

[0028] Beneficial effects of the present invention:

[0029] 1. The present invention combines UAV aerial survey technology with terrain supplementary survey using a variety of surveying methods to build a BIM Twins platform, and converts the model's longitude and latitude coordinates to project coordinates based on the preset image control point identification positions and the actual measured image control points to build a high-precision three-dimensional model. Based on this three-dimensional model, the construction plan is imported, the earthwork volume is directly calculated by the cross-section method, and an earthwork report can be generated, which solves the problem that manual calculation combined with other software is complex, error-prone, and time-consuming, providing accurate data support for earthwork construction and saving project construction period.

[0030] 2. The present invention combines UAV aerial survey technology with terrain supplementary survey using a variety of measurement methods on the BIM Twins platform to solve the problem of original ground data deviation in areas blocked by vegetation, structures, and underwater obstructions during UAV aerial survey. It can restore the original terrain with high precision and efficiency, greatly improving the accuracy of subsequent earthwork calculations.

[0031] 3. The present invention is based on building a high-precision three-dimensional model, and measures information such as length, area and slope by directly and quickly extracting coordinates and elevation information on the three-dimensional real scene model. It solves the problem that a large number of surveyors need to spend a lot of time on field work and the safety of surveyors in complex terrain is difficult to ensure, saving manpower and construction time for the project.

[0032] 4. The present invention is based on building a high-precision three-dimensional model. During the project construction process, by importing the phased terrain survey data dat file, the earthwork excavation and filling volume can be efficiently and quickly calculated using the grid method. The excavation and filling conditions at various locations in the construction area can be intuitively seen, and an earthwork report can be generated to provide data support for each stage of earthwork construction.

[0033] Additional aspects and advantages of the present application will be partially given in the following description, which will become apparent from the following description, or will be understood through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0035] Figure 1 It is a flow chart of a high-precision earthwork measurement algorithm for building a three-dimensional model based on drone aerial survey in an embodiment of the present invention; DETAILED DESCRIPTION

[0036] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0037] Those skilled in the art will appreciate that, unless otherwise stated, the singular forms "a", "an", "said" and "the" used herein may also include plural forms. It should be further understood that the term "comprising" used in the specification of the present application refers to the presence of the features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0038] It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical terms and scientific terms) used herein have the same meaning as the general understanding of those skilled in the art to which this application belongs. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and will not be interpreted with an idealized or overly formal meaning unless specifically defined as in the embodiments of this application.

[0039] The purpose of the invention is to provide a high-precision earthwork measurement algorithm and system based on drone aerial survey to build a three-dimensional model; this method is constructed on the BIM Twins platform by combining drone aerial survey technology with terrain supplementary survey using multiple measurement methods, and based on the preset image control point identification positions and the actual measured image control points, the model longitude and latitude coordinates are converted to project coordinates to build a high-precision three-dimensional model. Based on this three-dimensional model, the construction plan is imported, the earthwork volume is calculated directly by the cross-section method, and an earthwork report can be generated, which solves the problem that manual calculation operations combined with other software are complex, error-prone and time-consuming, and provides accurate data support for earthwork construction and saves project construction period.

[0040] Embodiment 1:

[0041] like Figure 1 As shown, an embodiment of the present invention provides a high-precision earthwork measurement algorithm for constructing a three-dimensional model based on drone aerial survey, including:

[0042] S100, pre-arrange image control points and check points in the area to be measured; start collecting drone aerial survey image data, and conduct supplementary surveys on the area blocked by obstacles to obtain supplementary survey data;

[0043] Specifically: The UAV data collection operation process is divided into aerial survey preparation, UAV pre-takeoff preparation and aerial survey image data collection. Choose the appropriate weather and time for aerial survey before aerial survey. Correctly set RTK parameters, route planning, flight parameters, and camera parameters during aerial survey.

[0044] The preparation stage of aerial survey mainly involves field exploration of the survey area to understand the general topography of the survey area. According to the requirements of the survey area and the resolution of aerial survey images, image control points are evenly arranged inside the survey area. Image control points should be arranged in a location with relatively flat terrain and wide field of vision. Image control points should be painted on site with a right-angle mold or with special aerial survey marks: the painting size should be >50cm, and the corners should not be virtual; the number should be painted, the font should be clear, and the font height should be >30cm. The spacing between each is 100 to 200 meters. The image control point measurement mainly adopts the "GPS RTK" method. The "GPS RTK" is verified by the GPS coordinate system parameter conversion and correction method. The control point acquisition function of GPS is used to collect the three-dimensional coordinate data of the image control points. The acquisition time for each acquisition shall not be less than 60 seconds. The acquisition is carried out three times, and the average is taken and saved for backup. After that, checkpoints are evenly arranged inside the survey area. There is no requirement for the spacing between the arrangements. Other requirements are the same as those for the arrangement and data acquisition of image control points. Drone aerial surveys require good weather. Drone flights are not allowed in weather conditions such as strong winds, rain, lightning, and heavy fog. Operations should be carried out in weather conditions with good atmospheric visibility.

[0045] Before the drone takes off, the flight route should be planned first. The planned aerial survey range should completely cover the designed survey area, and expand by no less than 50 meters on the basis of the original survey area to ensure that the edge photos meet the resolution requirements when taking aerial survey photos. Secondly, set the photo overlap rate. Generally, the heading overlap rate of drone aerial survey is recommended to be no less than 75%, and the lateral overlap rate is no less than 70%. It can be adjusted according to the measurement progress requirements; then set the drone operating altitude. The set drone flight altitude must not be lower than the obstacle height in the survey area to avoid collision accidents; finally, check whether other functions of the drone, such as GPS positioning, visual sensors, compass, obstacle avoidance radar, etc., are operating normally. If some functions are not operating normally, they can be checked and corrected according to the prompts. Only after all function tests are passed can the flight mission be performed. In the process of performing the flight mission, the pilot needs to pay attention to the dynamics of the aircraft by visually observing the drone at all times, and pay attention to the battery status, flight speed, flight altitude, flight attitude, route completion status, etc. in the flight control software to ensure flight safety.

[0046] Other measurement methods: Topographic supplementary survey is mainly for obstacles inside the survey area. UAV aerial survey images cannot directly reflect the ground terrain conditions. Other measurement methods can be used to supplement the terrain. For areas with obstacles such as trees and houses, a total station can be used to collect three-dimensional coordinate data S04-2. For areas with low plants on the ground, GPS can be used for three-dimensional coordinate data collection S04-1. For ponds and large water areas, unmanned water survey ships can be used for data collection S04-3, and then three-dimensional coordinate data can be extracted.

[0047] S200, based on the BIM Twins platform, import the aerial survey image data to generate a real-scene three-dimensional model;

[0048] Specifically: Importing the image data with RTK information collected by drones into the BIM Twins platform can achieve high-precision and high-efficiency 3D model construction. For the drone image data imported into the platform, you first need to check the integrity and availability of the data, then set various parameters, the software automatically matches the feature points, and then performs aerial triangulation to obtain a point cloud composed of points with the same name, then perform dense matching of multi-view images, build a model with points with the same name, and then connect the point clouds to build a 3D grid, and finally perform texture mapping on the model to produce a 3D model.

[0049] S300, find the image control point identification position on the three-dimensional model and match it with the actual measured image control point. After matching all the image control points, convert the model longitude and latitude coordinates to project coordinates, regenerate the three-dimensional model, import the check point coordinate data, and check the model accuracy. The accuracy check report is shown in Table 1.

[0050] Table 1

[0051]

[0052] Specifically: find the position of the image control point on the 3D model and match it with the actual measured image control point. After matching all the image control points, convert the model longitude and latitude coordinates to the project coordinates and regenerate the 3D model. Import the checkpoint coordinate data and generate a model accuracy report. If the requirements are met, you can proceed with subsequent operations. If the accuracy requirements are not met, you need to check the problem until the accuracy requirements are met.

[0053] The seven-parameter coordinate transformation process includes: setting the seven parameters to be three translation parameters (DX, DY, DZ), three rotation angles (RX, RY, RZ), and a scale factor S.

[0054] 1. Scale factor: A parameter that represents the proportional error between different map projections, represented by S.

[0055] Three rotation angles (RX, RY, RZ):

[0056] X-axis rotation angle: indicates the angle of X-axis rotation, expressed as RX.

[0057] Y-axis rotation angle: indicates the angle of Y-axis rotation, expressed as RY.

[0058] Z-axis rotation angle: indicates the angle of Z-axis rotation, represented by RZ.

[0059] Three translation parameters (DX, DY, DZ):

[0060] X-axis translation parameter: represents the translation amount in the X-axis direction, denoted by DX.

[0061] Y-axis translation parameter: represents the translation amount in the Y-axis direction, expressed as DY.

[0062] Z-axis translation parameter: represents the translation amount in the Z-axis direction, expressed as DZ.

[0063] Given the coordinates of the original model image control points (X, Y, Z), the actual project coordinates are (X1, Y1, Z1), and the calculation formula can be listed as follows:

[0064] X1=S*(X-RZ*Y+RY*Z)+DX

[0065] Y1=S*(RZ*X+Y-RX*Z)+DX

[0066] Z1=S*(-RY*X+RX*Y+Z)+DZ

[0067] By inputting at least three sets of coordinate data, the values ​​of seven parameters can be solved, and the seven parameters can be used to realize the conversion from model coordinates to project coordinates.

[0068] S400, importing the supplementary survey data, combining the three-dimensional coordinate data with the original model using surface fitting technology, completing terrain fitting, and generating a digital surface model;

[0069] Specifically: For areas with vegetation, structures, and underwater obstructions, the range of the obstructed area can be selected in the 3D model. In this area, the accuracy of terrain restoration can be increased by adding seed points. For example, GPS is used to measure the vegetation area to obtain terrain data, and unmanned watercraft is used to conduct underwater measurements to obtain underwater terrain data. Finally, through the Glodon BIM Twins platform, a variety of measurement methods are combined to eliminate the water surface and vegetation, import underwater terrain data and plant protection area terrain data, and use surface fitting technology to combine the 3D coordinate data with the original model to complete terrain fitting, thereby completing the high-precision and high-efficiency restoration of the original terrain and generating a digital surface model (Digital Surface Model, abbreviated DSM).

[0070] S500: extracting information, designing elevations, and calculating earthwork based on the digital surface model.

[0071] Specifically: coordinates and elevation information can be extracted from the three-dimensional real-life model, and the terrain extraction algorithm that incorporates graphics technology can be used to accurately measure information such as length, area, and slope; the selected model can be directly calculated, and the flat field elevation or design elevation can be selected during calculation, and the corresponding parameters can be imported into the platform. The calculation is performed using the triangulation method, and the model after calculation can view the details of the excavation and filling, and a report on the excavation and filling of this part can be issued; the construction plan (including the center line of the river, mileage pile number, red line, design cross section, etc.) can be imported. The BIM Twins platform automatically generates the current surface cross-section diagram, and the three-dimensional coordinates of any point on the cross-section can be viewed to check whether the cross-section line fits the surface. Combined with the design cross-section, the excavation and filling area of ​​each cross-section is calculated to obtain the earthwork volume between the two cross-sections. Combined with the cross-section within the red line, the total amount of excavation and filling within the red line is summarized. Specifically, let the original ground section curve function be y = f(x), and the design section curve function be y = g(x). Then, in the range [a, b], the area enclosed by the two curves can be expressed as S = ∫ b a(f(x)-g(x)dx), assuming that the areas of two adjacent sections are S1 and S2, the distance between the two sections is H, and the earthwork volume is V, then V=1 / 2(S1+S2)H, assuming that the earthwork volume between two adjacent sections is V1, V2, V3...Vn, then Vtotal=V1+V2+V3+......+Vn; further, through the platform, the dwg format section diagram of each pile number (the current surface section combined with the designed section) can be exported, and the specific conditions of each section can be viewed in CAD; the dat format three-dimensional coordinate data of the current surface section line and the summary table of earthwork excavation and filling volume can also be exported.

[0072] Furthermore, during the construction process, the original model and the post-construction model or the finished surface model are compared, and the amount of earthwork excavation and backfilling is calculated using the grid method, which can intuitively show the earthwork excavation and backfilling situation in each area grid. The two-phase earthwork calculation is based on the terrain calculation of the same area and different time periods, which can detect the progress of earthwork and construction reporting.

[0073] Embodiment 2:

[0074] In the embodiment of the present invention, two cross sections of the project are compared by manually measuring the topographic points and the cross section diagrams generated by BIMTwins modeling to verify the matching degree between the manual and system drawing of the filling and cutting volume. The specific matching degree is shown in Table 2:

[0075] Table 2

[0076]

[0077]

[0078] As can be seen from Table 2, the volume of earthfill measured by manual RTK is 1863m 3 The BIM Twins modeling fill volume is 1743m 3 , a difference of 129m 3 The excavation volume measured by manual RTK is 105154m 3 , the BIM Twins modeling fill volume is 105669m 3 , difference -515m 3 The matching degree between BIM Twins modeling and manual measurement of excavation is as high as 99.51%, while the matching degree is meaningless due to the small amount of fill.

[0079] Embodiment 3:

[0080] The embodiment of the present invention provides a high-precision earthwork measurement system based on drone aerial survey to build a three-dimensional model, including: a first module for pre-arranging image control points and check points in the area to be measured, starting drone aerial survey data collection, and supplementing the area blocked by obstacles; based on the BIM Twins platform, importing the aerial survey image data to generate a real-scene three-dimensional model;

[0081] The second module is used to find the image control point identification position on the three-dimensional model and match it with the actual measured image control points. After matching all the image control points, the model longitude and latitude coordinates are converted to project coordinates, the three-dimensional model is regenerated, and the checkpoint coordinate data is imported to verify the model accuracy.

[0082] The third module is used to import the supplementary survey data, combine the three-dimensional coordinate data with the original model using surface fitting technology, complete terrain fitting, and generate a digital surface model;

[0083] The fourth module is used to extract information, design elevation and calculate earthwork based on the digital surface model.

[0084] Embodiment 4:

[0085] An embodiment of the present invention provides a computer device, including a processor, a memory, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, any step of the high-precision earthwork measurement algorithm for constructing a three-dimensional model based on drone aerial survey as described in Example 1 is implemented.

[0086] Embodiment 5:

[0087] An embodiment of the present invention provides a computer-readable storage medium, which stores a computer program; when the computer program is executed by a processor, any step of the high-precision earthwork measurement algorithm for constructing a three-dimensional model based on drone aerial survey as described in Example 1 is implemented.

[0088] It should be understood that, although the steps in the flowchart of the accompanying drawings are displayed in sequence as indicated by the arrows, these steps are not necessarily executed in sequence in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least a part of the steps in the flowchart of the accompanying drawings may include multiple sub-steps or multiple stages, and these sub-steps or stages are not necessarily executed at the same time, but can be executed at different times, and their execution order is not necessarily sequential, but can be executed in turn or alternately with other steps or at least a part of the sub-steps or stages of other steps.

[0089] The above description is only a partial implementation method of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A high-precision earthwork measurement method based on drone aerial survey to build a three-dimensional model, characterized in that: include: S100, pre-deploy image control points and checkpoints in the area to be measured; start collecting drone aerial survey image data, and use other methods to conduct supplementary surveys on the area blocked by obstacles to obtain supplementary survey data; S200, importing the aerial survey image data to generate a real-scene three-dimensional model; S300, finding the image control point identification position on the three-dimensional model and matching it with the actual measured image control points, converting the model longitude and latitude coordinates to the project coordinates after all image control points are matched, regenerating the three-dimensional model, and importing the checkpoint coordinate data to verify the model accuracy; S400, importing the supplementary survey data, combining the three-dimensional coordinate data of the seed point with the original model using surface fitting technology, completing terrain fitting, and generating a digital surface model; S500: extracting information, designing elevations, and calculating earthwork based on the digital surface model.

2. According to claim 1, a high-precision earthwork measurement method based on drone aerial survey to build a three-dimensional model is characterized in that: Image control point measurement mainly verifies "GPS RTK" through GPS coordinate system parameter conversion and correction methods. The control point acquisition function of GPS is used to collect the three-dimensional coordinate data of the image control points. The acquisition time for each time must not be less than 60 seconds. After multiple acquisitions, the average is taken and saved for later use.

3. The high-precision earthwork measurement method based on drone aerial survey to construct a three-dimensional model according to claim 1 is characterized in that: The other methods of supplementary surveying the obstacle-blocked areas include: collecting three-dimensional coordinate data through a total station for general obstacle areas; collecting three-dimensional coordinate data through GPS for areas with low plants on the ground; and collecting data through an unmanned water survey vessel for large water surface areas.

4. The high-precision earthwork measurement method based on drone aerial survey to construct a three-dimensional model according to claim 2 is characterized in that: Step S200 specifically includes: importing image data with RTK information collected by the drone, checking the integrity and availability of the data, setting various parameters, the software automatically matches feature points and then performs aerial triangulation operations to obtain a point cloud composed of points with the same name, then performs dense matching of multi-view images, builds a model with points with the same name, connects the point clouds to build a three-dimensional grid, and finally performs texture mapping on the model to produce a three-dimensional model.

5. The high-precision earthwork measurement method based on drone aerial survey to construct a three-dimensional model according to claim 1 is characterized in that: The conversion of the model longitude and latitude coordinates to the project coordinates in step S300 includes: assuming that the seven parameters are three translation parameters (DX, DY, DZ), three rotation angles (RX, RY, RZ) and a scale factor S; the original model image control point coordinates (X, Y, Z) are known, and the actual project coordinates are (X1, Y1, Z1), and the calculation formula can be listed as follows: X1=S*(X-RZ*Y+RY*Z)+DX Y1=S*(RZ*X+Y-RX*Z)+DX Z1=S*(-RY*X+RX*Y+Z)+DZ Wherein, RX represents the angle of rotation about the X-axis; RY represents the angle of rotation about the Y-axis; RZ represents the angle of rotation about the Z-axis; DX represents the amount of translation in the X-axis direction; DY represents the amount of translation in the Y-axis direction; and DZ represents the amount of translation in the Z-axis direction.

6. The high-precision earthwork measurement method based on drone aerial survey to construct a three-dimensional model according to claim 5 is characterized in that: include: The seven parameter values ​​can be solved by bringing in at least three sets of coordinate data, and bringing in the seven parameters can realize the conversion from model coordinates to project coordinates.

7. A high-precision earthwork measurement method based on drone aerial survey to construct a three-dimensional model according to any one of claims 1 to 6, characterized in that: Step S500 includes: importing the construction plan, automatically generating the current surface section diagram, combining it with the design section, calculating the excavation and filling area of ​​each section, obtaining the earthwork volume between the two sections, combining it with the section within the red line, and summarizing the total amount of excavation and filling within the red line.

8. A high-precision earthwork measurement system based on drone aerial survey to build a three-dimensional model, characterized in that: include: The first module is used to pre-deploy image control points and checkpoints in the area to be measured, start drone aerial survey data collection, and conduct supplementary surveys in areas blocked by obstacles; Importing the aerial survey image data to generate a real-scene three-dimensional model; The second module is used to find the image control point identification position on the three-dimensional model and match it with the actual measured image control points. After matching all the image control points, the model longitude and latitude coordinates are converted to project coordinates, the three-dimensional model is regenerated, and the checkpoint coordinate data is imported to verify the model accuracy. The third module is used to import the supplementary survey data, combine the three-dimensional coordinate data with the original model using surface fitting technology, complete terrain fitting, and generate a digital surface model; The fourth module is used to extract information, design elevation and calculate earthwork based on the digital surface model.

9. A computer device, characterized in that: The method comprises a processor, a memory, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, a high-precision earthwork measurement algorithm for constructing a three-dimensional model based on drone aerial survey as described in any one of claims 1 to 7 is implemented.

10. A computer-readable storage medium, characterized in that The computer storage medium stores a computer program; when the computer program is executed by the processor, the high-precision earthwork measurement algorithm for constructing a three-dimensional model based on drone aerial survey as described in any one of claims 1 to 7 is implemented.

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