High-precision earthwork measurement algorithm and system based on unmanned aerial vehicle photogrammetry for constructing three-dimensional model

Abstract

The application discloses a high-precision earthwork measurement algorithm and system for constructing a three-dimensional model based on unmanned aerial vehicle aerial survey, and the method comprises the following steps: arranging image control points and check points in a to-be-measured area in advance; starting unmanned aerial vehicle aerial survey image data collection, and performing supplementary measurement on an obstacle-shielded area to obtain supplementary data; importing the aerial survey image data to generate a real scene three-dimensional model; finding an image control point mark position on the three-dimensional model and corresponding puncture points of actual measured image control points, converting model latitude and longitude coordinates into project coordinates after matching all the image control points, regenerating a three-dimensional model, and importing check point coordinate data to verify the model precision. Seed points are added to remove obstacles and restore the ground terrain, and then drawings and design elevations are imported to perform high-precision earthwork calculation, so that the problems of complex calculation operation, easy errors and large time consumption of manual operation combined with other software are solved, accurate data support is provided for earthwork construction, and the project construction period is saved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of engineering construction technology, and particularly relates to a high-precision earthwork measurement algorithm and system for constructing a three-dimensional model based on unmanned aerial vehicle aerial survey. BACKGROUND

[0002] With the acceleration of urbanization and the development of infrastructure construction, earthwork engineering plays an important role in various construction projects. Earthwork engineering not only involves land leveling, excavation, but also relates to filling, transportation and other links, and is one of the basic work to ensure the smooth progress of the project. Traditional earthwork calculation methods, such as the cross-section method, square grid method, contour method and digital elevation model (DEM) method, although meet the engineering requirements to some extent, have many limitations in efficiency and accuracy.

[0003] At present, the existing earthwork calculation methods in China mainly include the cross-section method, square grid method, contour method and DEM method. Among them, the DEM method estimates the earthwork volume by constructing a digital terrain model, which has higher accuracy than other methods, but still cannot meet the demand of real-time feedback and checking of earthwork volume in the construction stage. In recent years, with the rapid development of unmanned aerial vehicle technology, using unmanned aerial vehicle for oblique photogrammetry has become a new technology. This method not only improves the work efficiency and reduces the labor cost, but also can obtain high-density and full-coverage measurement data in complex terrain conditions, providing a solid foundation for subsequent three-dimensional modeling.

[0004] Among them, the traditional earthwork calculation method has large error in calculating the earthwork volume, the contour method requires large storage capacity for data and has complex data structure, and it is often difficult to establish, the DEM method can overcome the problem of redundant data in areas with small terrain undulations, and has higher accuracy than other methods, but still cannot meet the requirements of the construction stage, and cannot feedback and check the earthwork volume in the construction site in time, which is not conducive to the control of construction period and construction cost. The existing unmanned aerial vehicle survey technology is not suitable for the case of dense vegetation, dense buildings or water coverage, because there are trees, houses and other obstacles on the ground, resulting in a certain deviation between the established three-dimensional model and the actual ground surface, which has a great influence on the later earthwork calculation. In addition, the traditional method is difficult to accurately fit the ground surface when dealing with complex terrain, especially in the case of large-area vegetation or water removal, which is easy to cause large error in earthwork calculation. These problems limit the popularization and use of existing technology in practical application, and there is an urgent need for a new solution to overcome these defects to realize more accurate and efficient earthwork volume measurement. SUMMARY

[0005] In view of the above defects or improvement needs of the prior art, the purpose of the present application is to provide a high-precision earthwork measurement algorithm and system for constructing a three-dimensional model based on unmanned aerial vehicle photogrammetry; the method is constructed by combining unmanned aerial vehicle photogrammetry technology and various measurement methods of topographic supplementary survey on a BIM Twins platform, and based on the preset image control point identification position and the actual measured image control point, the model latitude and longitude coordinates are converted to project coordinates to construct a high-precision three-dimensional model, based on which a construction plan is imported, the earthwork volume is directly calculated by the section method, and an earthwork report can be generated, solving the problems of complex and error-prone manual calculation operation and the need to consume a large amount of time, and providing precise data support for earthwork construction and saving project duration.

[0006] To achieve this purpose, according to one aspect of the present application, a high-precision earthwork measurement algorithm for constructing a three-dimensional model based on unmanned aerial vehicle photogrammetry is provided, comprising:

[0007] S100, image control points and checkpoints are pre-deployed in the area to be measured; unmanned aerial vehicle photogrammetry image data acquisition is started, and obstacle-shielded areas are supplementary surveyed to obtain supplementary data;

[0008] S200, the photogrammetry image data is imported to generate a real three-dimensional model;

[0009] S300, the image control point identification position is found on the three-dimensional model and corresponding puncture is performed with the actual measured image control point, after all image control points are matched, the model latitude and longitude coordinates are converted to project coordinates, a three-dimensional model is regenerated, and checkpoint coordinate data is imported to verify the model accuracy.

[0010] S400, the supplementary data is imported, three-dimensional coordinate data is combined with the original model by using surface fitting technology, topographic fitting is completed, and a digital terrain model is generated;

[0011] S500, information extraction, elevation design, and earthwork calculation are performed based on the digital terrain model.

[0012] Further, the image control point measurement mainly verifies the "GPS RTK" by using the GPS coordinate system parameter conversion and correction method, uses the control point acquisition function of the GPS to collect three-dimensional coordinate data of the image control points, and the collection time of each time should not be less than 60 seconds, and the average of multiple times is saved for standby.

[0013] Further, the other way of supplementary surveying the obstacle-shielded areas includes: for general obstacle areas, three-dimensional coordinate data is collected by a total station; for areas with low plants on the ground, three-dimensional coordinate data is collected by a GPS; and for large-area water surface areas, data is collected by a waterborne unmanned surveying ship.

[0014] Further, the step S200 comprises: importing the image data with RTK information collected by the unmanned aerial vehicle, checking the integrity and usability of the data, setting various parameters, automatically matching the feature points by the software, performing the aerial triangulation operation to obtain the point cloud composed of the homonymic points, then performing the multi-view image dense matching, constructing the model by the homonymic points, connecting the point cloud to construct the three-dimensional grid, and finally performing the texture mapping on the model to produce the three-dimensional model.

[0015] Further, the conversion of the model latitude and longitude coordinates to the project coordinates in the step S300 comprises: setting seven parameters as 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 is 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] In the formula, RX represents the angle of X-axis rotation, RY represents the angle of Y-axis rotation, RZ represents the angle of Z-axis rotation, DX represents the translation amount in the X-axis direction, DY represents the translation amount in the Y-axis direction, and DZ represents the translation amount in the Z-axis direction.

[0020] Further, the conversion of the model latitude and longitude coordinates to the project coordinates in the step S300 comprises: setting seven parameters as 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 is as follows:

[0021] Further, the step S500 comprises: importing the construction plan, automatically generating the current ground section graph, combining with the design section, calculating the area product of each section in terms of excavation and filling, obtaining the earthwork between two sections, combining with the section within the red line, and summarizing to obtain the total amount of excavation and filling earthwork within the red line.

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

[0023] The second module is used for finding the corresponding piercing points of the identified positions of the photo control points on the three-dimensional model and the actual measured photo control points, converting the model longitude and latitude coordinates into project coordinates after matching all the photo control points, regenerating the three-dimensional model, and importing the checkpoint coordinate data to check the model precision.

[0024] The third module is used for importing the supplementary survey data, combining the three-dimensional coordinate data with the original model by using the curved surface fitting technology, completing the topographic fitting, and generating the digital terrain model.

[0025] The fourth module is used for information extraction, elevation design and earthwork calculation based on the digital terrain model.

[0026] According to a third aspect of the present application, a computer device is provided, which comprises a processor, a memory and a computer program stored in the memory and executable on the processor, and the processor implements any step of the high-precision earthwork measurement algorithm based on the three-dimensional model constructed by aerial survey of a UAV when executing the computer program.

[0027] According to a fourth aspect of the present application, a computer readable storage medium is provided, which stores a computer program; and the computer program is executable on a processor to implement any step of the high-precision earthwork measurement algorithm based on the three-dimensional model constructed by aerial survey of a UAV.

[0028] The present application has the following beneficial effects:

[0029] 1. The present application combines the UAV aerial survey technology and the topographic supplementary survey of various measurement methods to construct the BIM Twins platform, and converts the model longitude and latitude coordinates into project coordinates based on the preset identified positions of the photo control points and the actual measured photo control points, thereby constructing a high-precision three-dimensional model, importing the construction plan, directly calculating the earthwork quantity by the section method, and generating the earthwork report, which solves the problems of complex operation, easy error and large time consumption of manual operation combined with other software, and provides precise data support for earthwork construction and saves the project period.

[0030] 2. The present application combines the UAV aerial survey technology and the topographic supplementary survey of various measurement methods to construct the BIM Twins platform, which solves the problem of deviation of the original ground data of the UAV aerial survey for the areas of vegetation, structures and underwater shielding, and can restore the original topography with high precision and high efficiency, thereby greatly improving the accuracy of the later earthwork calculation.

[0031] 3. The present application is based on the construction of a high-precision three-dimensional model, directly and quickly extracts the coordinate and elevation information on the three-dimensional real scene model, measures the length, area and slope information, solves the problems of consuming a large amount of time for a large number of measurement personnel to go out for work and the difficulty in ensuring the safety of the measurement personnel in complex terrain, and saves manpower and period for the project.

[0032] 4. The present application is based on constructing high-precision three-dimensional model, in the project construction process, through importing the stage topographic survey data dat file, the earthwork excavation and filling amount is calculated efficiently and quickly by the grid method, and the excavation and filling situation of each position in the construction area can be directly observed, and the earthwork report can be generated, which provides data support for each stage of earthwork construction.

[0033] Additional aspects and advantages of the application will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following description and drawings. BRIEF DESCRIPTION OF DRAWINGS

[0034] The above and / or additional aspects and advantages of the present application will become apparent and be readily appreciated from the following description, including the accompanying drawings, wherein:

[0035] Figure 1 is a high-precision earthwork measurement algorithm flowchart based on unmanned aerial vehicle photogrammetry constructing three-dimensional model in an embodiment of the present application; DETAILED DESCRIPTION

[0036] The present application will be further described below in conjunction with the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present application, but not to limit the present application. In addition, it should be noted that, for the convenience of description, only the parts related to the present application are shown in the drawings, but not all the structures.

[0037] Those skilled in the art can understand that, unless specifically stated, the singular form "a", "an", "said" and "the" used herein also includes the plural form. It should be further understood that the phrase "comprising" used in the specification of the present application means that the features, integers, steps, operations, elements and / or components exist, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0038] Those skilled in the art can understand that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as that understood by those skilled in the art. It should also be understood that terms such as those defined in a general dictionary should be understood to have meanings consistent with those in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless specifically defined as such in the embodiments of the present 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 latitude and longitude 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 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, and provides accurate data support for earthwork construction and saves project construction time.

[0040] Example 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-deploy image control points and checkpoints in the area to be measured; start collecting drone aerial survey image data, and conduct supplementary surveys on areas blocked by obstacles to obtain supplementary survey data;

[0043] Specifically, the drone data collection process is divided into aerial survey preparation, drone takeoff preparation, and aerial survey image data collection. Before the survey, choose the appropriate weather and time for the survey. During the survey, correctly set RTK parameters, route planning, flight parameters, and camera parameters.

[0044] The aerial survey preparation phase primarily involves field exploration of the survey area to understand the general topography and terrain. Based on the survey area and the resolution of the aerial survey images, image control points (GCPs) are evenly distributed throughout the survey area. GCPs should be located on relatively flat terrain with a wide field of view. GCPs should be painted on-site using a rectangular mold or specialized aerial survey markings: the markings should be larger than 50 cm, with no sharp edges. The markings should be numbered in clear, clear fonts at least 30 cm high. GCPs should be spaced 100 to 200 meters apart. GCP measurement primarily utilizes GPS RTK, which is calibrated using GPS coordinate system parameter conversion and calibration methods. The GPS's control point acquisition function is used to collect 3D coordinate data for GCPs. Each acquisition should take at least 60 seconds. Three acquisitions should be performed, and the average value should be stored for future reference. Checkpoints are then evenly distributed throughout the survey area. There are no specific spacing requirements for GCPs. Other requirements for GCP placement and data collection are the same. Drone aerial surveys require good weather conditions. Drone flights are not allowed in strong winds, rain, lightning, heavy fog, etc. Operations should be carried out in weather conditions with good atmospheric visibility.

[0045] Before taking off, plan the flight route. The planned survey area should completely encompass the planned survey area and extend at least 50 meters beyond the original survey area to ensure that the edge images meet the required resolution. Next, set the photo overlap ratio. For drone surveys, a minimum of 75% overlap in the heading direction and 70% overlap in the lateral direction are recommended. This can be adjusted based on the survey schedule. Next, set the drone's operating altitude. The altitude must not be lower than the height of obstacles within the survey area to avoid collisions. Finally, check the drone's other functions, such as GPS positioning, visual sensors, compass, and obstacle avoidance radar, for proper operation. If any functions are not functioning properly, follow the prompts to check and correct them. Only after all functional tests have passed can the flight mission be carried out. During the flight, the pilot must constantly monitor the drone's movements and monitor the flight control software for battery status, flight speed, altitude, flight attitude, and route completion status to ensure flight safety.

[0046] Other surveying methods: Topographic resurveying is primarily used for areas with obstacles within the survey area. Drone aerial survey images cannot directly reflect the ground topography. Other surveying methods can be used to resurvey the terrain. For areas with obstacles such as trees and houses, a total station can be used for 3D coordinate data collection (S04-2). For areas with low vegetation, GPS can be used for 3D coordinate data collection (S04-1). For ponds and large water surfaces, unmanned water survey vessels can be used for data collection (S04-3), followed by extraction of 3D coordinate data.

[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 drone-captured imagery with RTK information into the BIM Twins platform enables high-precision and efficient 3D model construction. The imported drone image data must first be checked for integrity and availability, and then various parameters are set. The software automatically matches feature points and performs aerial triangulation to generate a point cloud composed of homonymous points. Dense multi-view image matching is then performed, and the model is constructed using homonymous points. The point clouds are then connected to form a 3D mesh, and texture mapping is performed to produce the 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 points. After matching all image control points, convert the model longitude and latitude coordinates to project coordinates, regenerate the three-dimensional model, import the checkpoint coordinate data, and verify the model accuracy. The accuracy check report is shown in Table 1.

[0050] Table 1

[0051]

[0052] Specifically: find the corresponding point on the three-dimensional model and the actual measurement of the control point to match the point, complete all the control points on the model latitude and longitude coordinates to the project coordinate conversion, regenerate the three-dimensional model. Import checkpoint coordinate data, generate model accuracy report, meet the requirements can be followed by operation. If it does not meet the accuracy requirements, the problem needs to be checked until the accuracy requirements are met.

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

[0054] Scale factor: a parameter representing the proportion error between different map projections, denoted by S.

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

[0056] X-axis rotation angle: represents the angle of X-axis rotation, denoted by RX.

[0057] Y-axis rotation angle: represents the angle of Y-axis rotation, denoted by RY.

[0058] Z-axis rotation angle: represents the angle of Z-axis rotation, denoted 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, denoted by DY.

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

[0063] Given the original model control point coordinates (X, Y, Z), the actual project coordinates are (X1, Y1, Z1), and the calculation formula can be written 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 bringing in at least three sets of coordinate data, the value of the seven parameters can be solved, and the model coordinate to project coordinate conversion can be realized by bringing in the seven parameters.

[0068] S400, import the supplementary data, combine the three-dimensional coordinate data with the original model using surface fitting technology, complete the terrain fitting, and generate 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 three-dimensional model. The accuracy of terrain restoration can be increased by adding seed points in this area. For example, use GPS to measure the terrain data of the vegetation area, use an unmanned boat to measure the underwater terrain data, etc. Finally, through the Guanglianda BIM Twins platform, combine various measurement methods, remove the water surface and vegetation, import the underwater terrain data and vegetation area terrain data, use surface fitting technology to combine the three-dimensional coordinate data with the original model, complete the terrain fitting, and thus complete the restoration of the original terrain with high precision and efficiency, generating a digital surface model (Digital Surface Model, abbreviated as DSM).

[0070] S500, based on the digital surface model, information extraction, elevation design, and earthwork calculation.

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

[0072] Further, in the construction process, the earthwork excavation and backfill quantities are calculated by comparing the original model and the post-construction model or the completed surface model by using the grid method, so that the earthwork excavation and filling quantities in each regional grid can be directly observed. The two-period earthwork calculation is based on the calculation of the topography of the same region at different time periods, and the progress of the earthwork and the construction report quantity can be detected.

[0073] Embodiment 2

[0074] In the embodiment of the application, the two cross sections of the project are compared by using the cross section drawing obtained by manually measuring the terrain points and the cross section drawing generated by BIM Twins modeling, to verify the matching degree of the earthwork excavation and filling quantities obtained by manual and system drawing, and the specific matching degree is shown in Table 2.

[0075] Table 2

[0076]

[0077]

[0078] As can be seen from Table 2, the earthwork filling quantity measured by manual RTK is 1863m 3 , the earthwork filling quantity measured by BIM Twins modeling is 1743m 3 , and the difference is 129m 3 . The earthwork excavation quantity measured by manual RTK is 105154m 3 , the earthwork filling quantity measured by BIM Twins modeling is 105669m 3 , and the difference is -515m 3 . The matching degree of the earthwork excavation quantity measured by BIM Twins modeling and manual measurement is as high as 99.51%, and the filling quantity is small, so the matching degree is meaningless.

[0079] Embodiment 3

[0080] The embodiment of the present application provides a high-precision earthwork measurement system based on a three-dimensional model constructed by unmanned aerial vehicle photogrammetry, comprising: a first module, used for pre-laying image control points and checkpoints in a to-be-measured area, starting unmanned aerial vehicle photogrammetry data collection, and performing supplementary measurement on an obstacle-shielded area; based on a BIM Twins platform, importing the photogrammetry image data to generate a real three-dimensional model;

[0081] A second module, used for finding an image control point identification position on the three-dimensional model and corresponding puncture points of actually measured image control points, performing model longitude and latitude coordinate to project coordinate conversion after matching all image control points, regenerating a three-dimensional model, and importing checkpoint coordinate data to verify model precision.

[0082] A third module, used for importing the supplementary measurement data, combining three-dimensional coordinate data and an original model by using a curved surface fitting technology, completing terrain fitting, and generating a digital terrain model;

[0083] A fourth module, used for performing information extraction, elevation design and earthwork calculation based on the digital terrain model.

[0084] Embodiment 4:

[0085] The embodiment of the present application provides a computer device, comprising 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 in the high-precision earthwork measurement algorithm based on a three-dimensional model constructed by unmanned aerial vehicle photogrammetry is realized.

[0086] Embodiment 5:

[0087] The embodiment of the present application provides a computer readable storage medium, the computer storage medium stores a computer program; when the computer program is executed by a processor, any step in the high-precision earthwork measurement algorithm based on a three-dimensional model constructed by unmanned aerial vehicle photogrammetry is realized.

[0088] It should be understood that, although each step in the flowchart of the accompanying drawings is displayed in sequence according to the direction of the arrow, these steps are not necessarily executed in sequence according to the direction of the arrow. Unless otherwise specified herein, the execution of these steps is not strictly limited in sequence, and they can be executed in other sequences. Moreover, at least part of the steps in the flowchart of the accompanying drawings can include multiple sub-steps or multiple stages, which are not necessarily executed at the same time, but can be executed at different times, and the execution sequence is not necessarily sequential, but can be executed alternately or alternately with at least part of other steps or other steps, sub-steps or stages.

[0089] The above merely describes some embodiments of the present application, and it should be pointed out that, for those skilled in the art, some improvements and refinements can be made without departing from the principles of the present application, and these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. A high-precision earthwork measurement algorithm for constructing a three-dimensional model based on unmanned aerial vehicle photogrammetry, characterized in that, Comprise: S100, pre-arrange control points and checkpoints in the area to be measured; start unmanned aerial vehicle aerial image data collection, and use other methods to supplement the measurement of obstacle-shielded areas to obtain supplementary data; S200, import the aerial image data to generate a real three-dimensional model; S300, find the control point identification position on the three-dimensional model and correspond to the actual measured control points, match all the control points, then convert the model latitude and longitude coordinates to the project coordinates, regenerate the three-dimensional model, and import the checkpoint coordinate data to verify the model accuracy; S400, import the supplementary data, use surface fitting technology, combine the supplementary data as seed points with the original model, complete the terrain fitting, and generate a digital terrain model; S500, based on the digital terrain model, extract information including length, area, and slope, as well as elevation design and earthwork calculation.

2. The high-precision earthwork measurement algorithm for constructing a three-dimensional model based on aerial survey of unmanned aerial vehicles according to claim 1, characterized in that, The control point measurement mainly checks the "GPS RTK" through the GPS coordinate system parameter conversion and correction method, uses the control point collection function of GPS to collect three-dimensional coordinate data of the control point, and the collection time is not less than 60 seconds each time, and the average value is saved after multiple collection. 3.The high-precision earthwork measurement algorithm based on the construction of a three-dimensional model by aerial survey of a UAV according to claim 1, wherein, Other ways to supplement the measurement of obstacle-shielded areas include: for general obstacle areas, use a total station to collect three-dimensional coordinate data; for areas with low plants on the ground, use GPS to collect three-dimensional coordinate data; for large water surface areas, use a waterborne unmanned surveying ship to collect data.

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 the image data collected by the unmanned aerial vehicle with RTK information, checking the completeness and usability of the data, setting various parameters, automatically matching the feature points by the software, then performing air triangulation operation to obtain point clouds composed of homonymous points, then performing multi-view image dense matching to construct a model using homonymous points, then connecting the point clouds to construct a three-dimensional grid, and finally performing texture mapping on the model to generate a three-dimensional model.

5. The high-precision earthwork measurement algorithm for constructing a three-dimensional model based on aerial survey of unmanned aerial vehicles according to claim 1, characterized in that, The conversion of the model latitude and longitude coordinates to the project coordinates in step S300 includes: setting seven parameters as three translation parameters DX, DY, DZ, three rotation angles RX, RY, RZ, and a scale factor S; the original model control point coordinates (X, Y, Z) are known, and the actual project coordinates are (X1, Y1, Z1); the calculation formula is as follows: X1=S*(X-RZ*Y+RY*Z)+DX Y1=S*(RZ*X+Y-RX*Z)+DY Z1=S*(-RY*X+RX*Y+Z)+DZ In the formula, RX represents the angle of X-axis rotation; RY represents the angle of Y-axis rotation; RZ represents the angle of Z-axis rotation; DX represents the translation amount in the X-axis direction; DY represents the translation amount in the Y-axis direction; and DZ represents the translation amount in the Z-axis direction. 6.The high-precision earthwork measurement algorithm based on the aerial survey of a UAV and the construction of a three-dimensional model, according to claim 5, characterized in that, Comprise: By bringing in at least three groups of coordinate data, the seven parameter values can be solved, and the conversion of the model latitude and longitude coordinates to the project coordinates can be realized by bringing in the seven parameters.

7. The high-precision earthwork measurement algorithm for constructing a three-dimensional model based on unmanned aerial vehicle photogrammetry according to any one of claims 1-6, characterized in that, Step S500 includes: importing construction plan, automatically generating present situation ground section view, combining with design section, calculating each section excavation and filling aspect product, obtaining earthwork between two sections, combining with red line section, and summarizing to obtain total amount of red line excavation and filling earthwork.

8. A high-precision earthwork measurement system for constructing a three-dimensional model based on unmanned aerial vehicle photogrammetry, characterized by, Comprise: The first module is used for laying image control points and check points in the to-be-measured area in advance; starting unmanned aerial vehicle aerial survey image data collection, and supplementing the measurement of the obstacle-shielded area by using other ways to obtain supplement data; and importing the aerial survey image data to generate a real scene three-dimensional model; The second module is used for finding the image control point mark position on the three-dimensional model and corresponding puncture with the actually measured image control points, performing model latitude and longitude coordinate to project coordinate conversion after matching all the image control points, regenerating a three-dimensional model, and importing check point coordinate data to verify the model precision; The third module is used for importing the supplement data, combining the supplement data with the original model as seed points by using curved surface fitting technology, completing terrain fitting, and generating a digital ground surface model; The fourth module is used for extracting information including length, area and slope based on the digital ground surface model, and designing elevation and calculating earthwork.

9. A computer apparatus, comprising: The computer program is stored in the memory and can be run on the processor, and the processor implements the high-precision earthwork measurement algorithm based on the unmanned aerial vehicle aerial survey three-dimensional model construction according to any one of claims 1-7 when the computer program is executed.

10. A computer readable storage medium, characterized in that, The computer storage medium stores a computer program; and the computer program is executed by the processor to implement the high-precision earthwork measurement algorithm based on the unmanned aerial vehicle aerial survey three-dimensional model construction according to any one of claims 1-7.

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