Rapid and refined three-dimensional numerical modeling method, system, equipment and storage medium based on unmanned aerial vehicle photogrammetry

Abstract

The present invention discloses a method, system, device and storage medium for rapid and refined three-dimensional numerical modeling based on unmanned aerial vehicle photogrammetry, which belongs to the field of three-dimensional numerical modeling of landslides (slopes). The method includes obtaining a first native three-dimensional grid; obtaining a three-dimensional grid A of the slope range; obtaining a three-dimensional grid B of the terrain surface; generating a curved surface by a curtain; obtaining the final three-dimensional terrain, i.e., grid C; obtaining a watertight three-dimensional model; and gridding the three-dimensional model to obtain a three-dimensional numerical model. The present application can perform precision-differentiated modeling for different regions, improve the precision of key calculation areas, and reduce the precision of other regions; after converting it into a three-dimensional numerical model, the purpose of optimizing the number of three-dimensional numerical model grids and reducing the overall calculation amount of the model is achieved; the rapidly established refined three-dimensional numerical model improves the precision of numerical simulation, and provides effective support for three-dimensional numerical simulation analysis and the research and decision-making of relevant personnel.

Description

Technical Field

[0001] The present invention belongs to the technical field of three-dimensional numerical modeling of landslides (slopes), and in particular relates to a fast and refined three-dimensional numerical modeling method, system, equipment and storage medium based on unmanned aerial vehicle photogrammetry. Background Art

[0002] The construction of three-dimensional numerical model of landslide (slope) has always been a difficult problem in numerical simulation of landslide (slope). At present, the three-dimensional numerical simulation software widely used in geotechnical engineering field includes the continuum mechanics software FLAC developed by Itasca Consulting Group in the United States. 3D , discrete medium mechanics software 3DEC, etc., they generally have the problems of weak early modeling capabilities and poor flexibility, and it is difficult to construct three-dimensional numerical models with complex terrain.

[0003] Landslide (slope) terrain is generally more complex. The three-dimensional terrain modeling is generally based on the point cloud or DSM established by UAV photogrammetry. Point clouds with appropriate density are extracted from the DSM, or the dense original point cloud data is thinned. On this basis, suitable contour lines are generated, or the processed point cloud is directly used to fit the terrain surface in the three-dimensional modeling software to finally establish the three-dimensional terrain. The three-dimensional terrain modeling based on UAV photogrammetry is mostly an indirect processing method, which is cumbersome and has a relatively slow processing speed. In addition, in the process of extracting point clouds from DSM, generating contour lines through DSM, and thinning the dense original point cloud data, it is impossible to intuitively and accurately know the accuracy of the processed data, and it is impossible to confirm that the feature data can be extracted or retained. Ultimately, it is difficult to obtain the desired refined three-dimensional numerical model. Summary of the invention

[0004] The purpose of the present invention is to provide a method, system, device and storage medium for quickly and finely refining a three-dimensional numerical model based on unmanned aerial vehicle photogrammetry, so as to solve the problem that the existing three-dimensional numerical model of landslide (slope) is slow to build and it is difficult to obtain the desired fine three-dimensional numerical model.

[0005] The embodiment of the present application is implemented as follows: a method for rapidly refining a three-dimensional numerical model based on drone photogrammetry, comprising:

[0006] Import the original real-life 3D model into Rhinoceros to obtain the first original 3D mesh;

[0007] The first native three-dimensional grid is clipped to obtain a three-dimensional grid A in the slope range;

[0008] The original real-scene 3D model is imported into Rhinoceros again to obtain a second original 3D mesh, and the second original 3D mesh is reduced and quadrilateralized to obtain a 3D mesh B of the terrain surface;

[0009] Open Grid A and Grid B, so that all Grid B is under Grid A;

[0010] Select the range of mesh A and mesh B, and the curtain will generate the surface;

[0011] Convert the surface into a mesh to obtain the final three-dimensional terrain, i.e., mesh C;

[0012] On the basis of the grid C, the slope surface, slope bottom, terrain surface around the slope, stratum interface and base of the three-dimensional model are constructed and combined together to obtain a watertight three-dimensional model;

[0013] The three-dimensional model is meshed to obtain a three-dimensional numerical model.

[0014] Optionally, in some embodiments of the present application, the format of the native real-scene 3D model is .obj; and / or

[0015] The slope includes a landslide or a side slope.

[0016] Optionally, in some embodiments of the present application, the native real-scene three-dimensional model is obtained by photogrammetry of a drone and then three-dimensionally reconstructed using three-dimensional real-scene modeling software, and the three-dimensional real-scene modeling software includes one or more of DJI Zhitu, ContextCapture, and Pix4D.

[0017] Optionally, in some embodiments of the present application, the slope range is outlined in AutoCAD or ArcGIS software according to the slope range obtained by field investigation, saved in .dxf format and imported into Rhinoceros to crop the three-dimensional grid A of the slope range.

[0018] Optionally, in some embodiments of the present application, the surface is converted into a grid, the scope of the proposed model is obtained according to a field survey, and the scope of the proposed model is clipped to obtain the final three-dimensional terrain, namely, the grid C.

[0019] Optionally, in some embodiments of the present application, the method for obtaining a watertight three-dimensional model includes:

[0020] On the basis of the grid C, the slope surface and slope bottom of the three-dimensional model are constructed;

[0021] Construct the terrain surface around the slope in the 3D model;

[0022] Construct the stratigraphic interface within the scope of the 3D model;

[0023] Build the base of the three-dimensional model;

[0024] On the basis of the grid C, the slope surface, slope bottom, terrain surface around the slope, stratum interface and base of the three-dimensional model are combined together to obtain a watertight three-dimensional model.

[0025] Optionally, in some embodiments of the present application, a Griddle plug-in is used in Rhinoceros to grid the three-dimensional model to obtain a three-dimensional numerical model.

[0026] Accordingly, the embodiment of the present application also provides a fast and refined three-dimensional numerical modeling system based on drone photogrammetry, including:

[0027] Import module, used to import the original real-life 3D model into Rhinoceros to obtain the first original 3D mesh;

[0028] A clipping module, used for clipping the first native three-dimensional grid to obtain a three-dimensional grid A in a slope range;

[0029] The reduction and quadrilateral reconstruction module is used to import the original real-scene 3D model into Rhinoceros again to obtain a second original 3D mesh, and to reduce and quadrilateralize the second original 3D mesh to obtain a 3D mesh B of the terrain surface;

[0030] Overlay module, open grid A and grid B, so that all grid B is under grid A;

[0031] In the curtain surface generation module, select the range of mesh A and mesh B to generate the curtain surface;

[0032] The surface-to-grid module is used to convert the surface into a grid to obtain the final three-dimensional terrain, i.e., the grid C;

[0033] Construct a watertight three-dimensional model module. On the basis of the grid C, construct the slope surface, slope bottom, terrain surface around the slope, stratum interface and base of the three-dimensional model, and combine them together to obtain a watertight three-dimensional model.

[0034] The meshing module is used to mesh the three-dimensional model to obtain a three-dimensional numerical model.

[0035] Accordingly, an embodiment of the present application also provides a computer device, including a storage device and a processor, wherein the storage device stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the above method.

[0036] Accordingly, an embodiment of the present application also provides a computer-readable storage medium storing a computer program, and when the computer program is executed by a processor, the processor executes the steps of the above method.

[0037] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0038] The modeling method of the present application can perform differentiated accuracy modeling for different areas, improve the accuracy of key calculation areas, and reduce the accuracy of other areas; after converting it into a three-dimensional numerical model, it can achieve the purpose of optimizing the number of grids in the three-dimensional numerical model and reducing the overall calculation amount of the model; the quickly established refined three-dimensional numerical model improves the accuracy of numerical simulation, and provides effective support for three-dimensional numerical simulation analysis and the research and decision-making of related personnel. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a flow chart of the method for rapidly refining three-dimensional numerical modeling based on unmanned aerial vehicle photogrammetry of the present invention;

[0040] Figure 2 A real-scene 3D model in .obj format provided in an embodiment of the present invention;

[0041] Figure 3 A native Mesh grid in .obj format provided by an embodiment of the present invention;

[0042] Figure 4 An aerial panoramic view of a slag pile slope of a certain waste dump provided by an embodiment of the present invention;

[0043] Figure 5 A close-up view of a slag pile slope at a certain waste dump provided by an embodiment of the present invention;

[0044] Figure 6 A measured cross-sectional view of a slag pile slope of a certain spoil site provided by an embodiment of the present invention;

[0045] Figure 7 The three-dimensional grid A is used to cut out the range of the slag slope;

[0046] Figure 8 is a second native three-dimensional mesh after the reduction process;

[0047] Fig. 9 The three-dimensional mesh B of the surface after quadrilateral reconstruction;

[0048] Fig.10 This is the image after grid A and grid B are superimposed;

[0049] Fig.11 Surface plot generated for the drapery;

[0050] Fig.12is the three-dimensional terrain, i.e., grid C;

[0051] Fig.13 The surface of the slope of the spoil dump;

[0052] Fig.14 It is the bottom surface of the slope of the spoil dump;

[0053] Fig.15 It is the terrain surface around the slope of the spoil dump;

[0054] Fig.16 It is the stratigraphic interface within the 3D model;

[0055] Fig.17 It is the base of the three-dimensional model;

[0056] Fig.18 For a complete three-dimensional model;

[0057] Fig.19 It is a gridded three-dimensional numerical model;

[0058] Fig. 20 Import FLAC for 3D numerical models 3D ,3DEC diagram;

[0059] Fig.21 Import diagrams of other numerical simulation platforms (ABAQUS, ANSYS) for 3D numerical models;

[0060] Fig. 22 for FLAC 3D Model calculation result cloud chart;

[0061] Fig.23 for FLAC 3D Cloud diagram of calculation results for the main section of the model. DETAILED DESCRIPTION

[0062] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0063] The technical solution of this application is as follows:

[0064] First, see Figure 1 The present application embodiment provides a method for rapidly refining a three-dimensional numerical model based on drone photogrammetry, including:

[0065] S1. Import the native real-life 3D model into Rhinoceros to obtain a first native 3D mesh;

[0066] S2, cutting the first native three-dimensional grid to obtain a three-dimensional grid A in the slope range;

[0067] S3, importing the original real-scene 3D model into Rhinoceros again to obtain a second original 3D mesh, reducing and reconstructing the second original 3D mesh into quadrilaterals to obtain a 3D mesh B of the terrain surface;

[0068] S4, open grid A and grid B, so that all grid B is under grid A;

[0069] S5, select the range of mesh A and mesh B, and generate the surface of the curtain;

[0070] S6, converting the surface into a grid to obtain the final three-dimensional terrain, i.e., grid C;

[0071] S7. On the basis of the grid C, construct the slope surface, the slope bottom, the terrain surface around the slope, the stratum interface and the base of the three-dimensional model, and combine them together to obtain a watertight three-dimensional model;

[0072] S8. Mesh the three-dimensional model to obtain a three-dimensional numerical model.

[0073] In this application, a low-cost small multi-rotor high-precision aerial survey drone is used to directly import the native real-life 3D model of the slope generated by drone photogrammetry into Rhinoceros to obtain a first native 3D grid; in the modeling process, a strategy of finely depicting the micro-topography of the slope body and reducing the influence of surrounding mountain vegetation is adopted, and the first native 3D grid is cropped to obtain a 3D grid A of the slope range; the native real-life 3D model is again imported into Rhinoceros to obtain a second native 3D grid, and the second native 3D grid is reduced and quadrilaterally reconstructed to simplify and smooth it. On this basis, the grids A and B are reconstructed. Grid B is overlapped, and local adjustments are made to ensure that the native grid of the slope area is always placed on the top, even if all grid B is located below grid A. The curtain method is used to control the slope terrain accuracy by adjusting the spacing of the curtain surface control points. During the whole process, the fitted terrain effect can be rendered in real time to help control the accuracy; the slope structure is constructed in Rhinoceros, specifically: the slope surface, slope bottom surface, terrain surface around the slope, stratum interface and base of the three-dimensional model are constructed, and combined together to obtain a watertight three-dimensional model, and the three-dimensional model is meshed to obtain a three-dimensional numerical model, which can be imported into multiple platforms for numerical simulation. The modeling method of this application can perform precision differentiated modeling for different areas, improve the accuracy of key calculation areas, and reduce the accuracy of other areas; after converting it into a three-dimensional numerical model, the purpose of optimizing the number of grids in the three-dimensional numerical model and reducing the overall calculation amount of the model is achieved; the refined three-dimensional numerical model established quickly improves the accuracy of numerical simulation, and provides effective support for three-dimensional numerical simulation analysis and research and decision-making of relevant personnel.

[0074] In S1:

[0075] In some embodiments, the version of Rhinoceros is Rhino 7.

[0076] As you can understand, Rhinoceros is a general-purpose professional 3D modeling software.

[0077] In some embodiments, the format of the native realistic 3D model is .obj.

[0078] It can be understood that the .obj format data file is a standard 3D model file format, such as Figure 2; This format was developed by AliasWavefront and is the standard 3D model file format for its 3D modeling and animation software Advanced Visualizer. In addition to the model file, the .obj format also requires a .jpg texture file. It generally includes three sub-files, namely .obj, .mtl, and .jpg. The .obj format is the most common Mesh file format, which uses vertices and triangles to express three-dimensional objects, such as Figure 3 .

[0079] In some embodiments, the native real-scene 3D model is obtained by photogrammetry using a drone and then 3D reconstruction using 3D real-scene modeling software, wherein the 3D real-scene modeling software includes one or more of DJI Zhitu, Context Capture, and Pix4D.

[0080] It can be understood that the real-life three-dimensional model is generated using drone oblique photography technology, that is, by using an optical camera mounted on the drone to simultaneously collect images from multiple angles such as vertical and oblique during the flight to obtain complete and accurate terrain information; oblique photography modeling software such as DJI Zhitu, Context Capture, Pix4D, etc. is used indoors to process drone aerial oblique photography data with a certain degree of overlap to obtain a real-life three-dimensional model (.obj format).

[0081] In some embodiments, in Rhinoceros, click File (F) → Import (I), select the file format .obj, import the native real-life 3D model into Rhinoceros, and obtain a first native 3D mesh.

[0082] In S2:

[0083] In some embodiments, the slope comprises a landslide or a side slope.

[0084] In some embodiments, the slope range is outlined in AutoCAD or ArcGIS software according to the slope range obtained from the field survey, and then imported into Rhinoceros after being saved in .dxf format to cut out the three-dimensional grid A of the slope range.

[0085] In the S3:

[0086] It is understandable that in areas with heavy vegetation coverage, the grid appears very messy, with sharp “spikes” in some areas. Since the terrain around the slope is not the focus of numerical simulation, it should be simplified and smoothed.

[0087] In some embodiments, the method for reducing the second native three-dimensional mesh includes clicking Mesh (M) → Edit Tool (E) → Reduce Mesh (R).

[0088] In some embodiments, the method of quadrilateral reconstruction includes clicking Subdivision Object (U) → Edit Tool (E) → Reconstruct Mesh with Quadrilaterals (Q), and reconstructing the reduced second native three-dimensional mesh using quadrilaterals to obtain a three-dimensional mesh B of the terrain surface.

[0089] It can be understood that the purpose of using quadrilateral reconstruction on the reduced second native three-dimensional mesh is to further improve the smoothness.

[0090] In S4:

[0091] It can be understood that grid A and grid B are opened, and through manual inspection and manual adjustment, it is ensured that within the slope range, all grid B is located below grid A. It can also be understood that making all grid B below grid A specifically means that within the range of grid A, all grid B is located below grid A.

[0092] In S5:

[0093] In some embodiments, switch the view of Rhinoceros to Top, click Surface (C) → Curtain (P), set the control point spacing value, select the range of Grid A and Grid B, and generate the surface with the curtain;

[0094] It can be understood that in this step, different control point spacing values ​​need to be tried to achieve the effect that best reflects the micro-topography of the slope.

[0095] In S6:

[0096] In some embodiments, click Mesh (M)→From NURBS Object (F) to convert the surface to a mesh.

[0097] In some embodiments, the scope of the proposed model is obtained according to field surveys, and the scope of the proposed model is clipped to obtain the final three-dimensional terrain, namely, the grid C.

[0098] In the S7:

[0099] It can be understood that the slope structure is further constructed in Rhinoceros, specifically: the slope surface, slope bottom, terrain surface around the slope, stratum interface and base of the three-dimensional model are constructed on the basis of the three-dimensional terrain, and finally the various parts are combined together to obtain a watertight three-dimensional model.

[0100] In some embodiments, the method of obtaining a watertight three-dimensional model includes:

[0101] S71. Based on the grid C, construct the slope surface and slope bottom of the three-dimensional model;

[0102] S72, constructing a terrain surface around the slope in the three-dimensional model;

[0103] S73, constructing a stratum interface within the scope of the three-dimensional model;

[0104] S74, constructing a base of the three-dimensional model;

[0105] S75, combining the parts from S71 to S74 to obtain a watertight three-dimensional model.

[0106] In S8:

[0107] In some embodiments, a Griddle plug-in is used in Rhinoceros to mesh the three-dimensional model to obtain a three-dimensional numerical model.

[0108] It can be understood that Griddle is a plug-in developed by Itasca for use in Rhinoceros software. Its function is to convert the established three-dimensional model in Rhinoceros software into a three-dimensional numerical model for numerical simulation analysis.

[0109] It can be understood that the three-dimensional numerical model obtained in this application can not only be used for numerical analysis in the ITASCA series software, but also supports import into other numerical simulation platforms such as ANSYS and ABAQUS.

[0110] In a second aspect, the embodiment of the present application provides a fast and refined three-dimensional numerical modeling system based on drone photogrammetry, including:

[0111] Import module, used to import the original real-life 3D model into Rhinoceros to obtain the first original 3D mesh;

[0112] A clipping module, used for clipping the first native three-dimensional grid to obtain a three-dimensional grid A in a slope range;

[0113] The reduction and quadrilateral reconstruction module is used to import the original real-scene 3D model into Rhinoceros again to obtain a second original 3D mesh, and to reduce and quadrilateralize the second original 3D mesh to obtain a 3D mesh B of the terrain surface;

[0114] Overlay module, open grid A and grid B, so that all grid B is under grid A;

[0115] In the curtain surface generation module, select the range of mesh A and mesh B to generate the curtain surface;

[0116] The surface-to-grid module is used to convert the surface into a grid to obtain the final three-dimensional terrain, i.e., the grid C;

[0117] Construct a watertight three-dimensional model module. On the basis of the grid C, construct the slope surface, slope bottom, terrain surface around the slope, stratum interface and base of the three-dimensional model, and combine them together to obtain a watertight three-dimensional model.

[0118] The meshing module is used to mesh the three-dimensional model to obtain a three-dimensional numerical model.

[0119] In the import module:

[0120] In some embodiments, the version of Rhinoceros is Rhino 7.

[0121] As you can understand, Rhinoceros is a general-purpose professional 3D modeling software.

[0122] In some embodiments, the format of the native realistic 3D model is .obj.

[0123] It can be understood that the .obj format data file is a standard 3D model file format, such as Figure 2 ; This format was developed by AliasWavefront and is the standard 3D model file format for its 3D modeling and animation software Advanced Visualizer. In addition to the model file, the .obj format also requires a .jpg texture file. It generally includes three sub-files, namely .obj, .mtl, and .jpg. The .obj format is the most common Mesh file format, which uses vertices and triangles to express three-dimensional objects, such as Figure 3 .

[0124] In some embodiments, the native real-scene 3D model is obtained by photogrammetry using a drone and then 3D reconstruction using 3D real-scene modeling software, wherein the 3D real-scene modeling software includes one or more of DJI Zhitu, Context Capture, and Pix4D.

[0125] It can be understood that the real-life three-dimensional model is generated using drone oblique photography technology, that is, by using an optical camera mounted on the drone to simultaneously collect images from multiple angles such as vertical and oblique during the flight to obtain complete and accurate terrain information; oblique photography modeling software such as DJI Zhitu, Context Capture, Pix4D, etc. is used indoors to process drone aerial oblique photography data with a certain degree of overlap to obtain a real-life three-dimensional model (.obj format).

[0126] In some embodiments, in Rhinoceros, click File (F) → Import (I), select the file format .obj, import the native real-life 3D model into Rhinoceros, and obtain a first native 3D mesh.

[0127] In the cutting module:

[0128] In some embodiments, the slope range is outlined in AutoCAD or ArcGIS software according to the slope range obtained from the field survey, and then imported into Rhinoceros after being saved in .dxf format to cut out the three-dimensional grid A of the slope range.

[0129] In the reduction and quadrilateral reconstruction module:

[0130] It is understandable that in areas with heavy vegetation coverage, the grid appears very messy, with sharp “spikes” in some areas. Since the terrain around the slope is not the focus of numerical simulation, it should be simplified and smoothed.

[0131] In some embodiments, the method for reducing the second native three-dimensional mesh includes clicking Mesh (M) → Edit Tool (E) → Reduce Mesh (R).

[0132] In some embodiments, the method of quadrilateral reconstruction includes clicking Subdivision Object (U) → Edit Tool (E) → Reconstruct Mesh with Quadrilaterals (Q), and reconstructing the reduced second native three-dimensional mesh using quadrilaterals to obtain a three-dimensional mesh B of the terrain surface.

[0133] It can be understood that the purpose of using quadrilateral reconstruction on the reduced second native three-dimensional mesh is to further improve the smoothness.

[0134] In the superposition module:

[0135] It can be understood that grid A and grid B are opened, and through manual inspection and manual adjustment, it is ensured that within the slope range, all grid B is located below grid A. It can also be understood that making all grid B below grid A specifically means that within the range of grid A, all grid B is located below grid A.

[0136] In the curtain surface generation module:

[0137] In some embodiments, switch the view of Rhinoceros to Top, click Surface (C) → Curtain (P), set the control point spacing value, select the range of Grid A and Grid B, and generate the surface with the curtain;

[0138] It can be understood that in this step, different control point spacing values ​​need to be tried to achieve the effect that best reflects the micro-topography of the slope.

[0139] In the surface-to-mesh module:

[0140] In some embodiments, click Mesh (M)→From NURBS Object (F) to convert the surface to a mesh.

[0141] In some embodiments, the scope of the proposed model is obtained according to field surveys, and the scope of the proposed model is clipped to obtain the final three-dimensional terrain, namely, the grid C.

[0142] In the module for constructing a watertight three-dimensional model:

[0143] It can be understood that the slope structure is further constructed in Rhinoceros, specifically: the slope surface, slope bottom, terrain surface around the slope, stratum interface and base of the three-dimensional model are constructed on the basis of the three-dimensional terrain, and finally the various parts are combined together to obtain a watertight three-dimensional model.

[0144] In some embodiments, the method of obtaining a watertight three-dimensional model includes:

[0145] On the basis of the grid C, the slope surface and slope bottom of the three-dimensional model are constructed;

[0146] Construct the terrain surface around the slope in the 3D model;

[0147] Construct the stratigraphic interface within the scope of the 3D model;

[0148] Construct the base of the three-dimensional model;

[0149] On the basis of the grid C, the slope surface, slope bottom, terrain surface around the slope, stratum interface and base of the three-dimensional model are combined together to obtain a watertight three-dimensional model.

[0150] In the mesh partitioning module:

[0151] In some embodiments, a Griddle plug-in is used in Rhinoceros to mesh the three-dimensional model to obtain a three-dimensional numerical model.

[0152] It can be understood that Griddle is a plug-in developed by Itasca for use in Rhinoceros software. Its function is to convert the established three-dimensional model in Rhinoceros software into a three-dimensional numerical model for numerical simulation analysis.

[0153] It can be understood that the three-dimensional numerical model obtained in this application can not only be used for numerical analysis in the ITASCA series software, but also supports import into other numerical simulation platforms such as ANSYS and ABAQUS.

[0154] In a third aspect, the present application provides a computer device comprising a storage device and a processor, wherein the storage device stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the method for rapidly refining three-dimensional numerical modeling based on unmanned aerial vehicle photogrammetry as described above.

[0155] The computer device may be a desktop computer, a notebook, a PDA, a cloud server, etc. The computer device may interact with the user through a keyboard, a mouse, a remote control, a touch pad, or a voice control device.

[0156] The memory includes at least one type of readable storage medium, and the readable storage medium includes flash memory, hard disk, multimedia card, card-type memory (for example, SD or D interface display memory, etc.), random access memory (RAM), static random access memory (SRAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), programmable read-only memory (PROM), magnetic memory, disk, optical disk, etc. In some embodiments, the memory can be an internal storage unit of the computer device, such as a hard disk or memory of the computer device. In other embodiments, the memory can also be an external storage device of the computer device, such as a plug-in hard disk equipped on the computer device, a smart memory card (SmartMediaCard, SMC), a secure digital (SecureDigital, SD) card, a flash card (FlashCard), etc. Of course, the memory can also include both the internal storage unit of the computer device and its external storage device. In this embodiment, the memory is often used to store the operating system and various application software installed on the computer device, such as the program code of the method for rapid and refined three-dimensional numerical modeling based on drone photogrammetry, etc. In addition, the memory may also be used to temporarily store various types of data that have been output or are to be output.

[0157] The processor may be a central processing unit (CPU), a controller, a microcontroller, a microprocessor, or other data processing chip in some embodiments. The processor is generally used to control the overall operation of the computer device. In this embodiment, the processor is used to run the program code stored in the memory or process data, such as running the program code of the method for fast and refined three-dimensional numerical modeling based on drone photogrammetry.

[0158] In a fourth aspect, the present application provides a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, the processor executes the steps of the method for rapidly refining three-dimensional numerical modeling based on drone photogrammetry as described above.

[0159] Among them, the computer-readable storage medium stores an interface display program, and the interface display program can be executed by at least one processor so that the at least one processor performs the steps of the above-mentioned method for rapid and refined three-dimensional numerical modeling based on drone photogrammetry.

[0160] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment method can be implemented by means of software plus the necessary general hardware platform, and of course it can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, disk, CD), and includes a number of instructions for a terminal device (which can be a mobile phone, computer, server or network device, etc.) to execute the fast and refined three-dimensional numerical modeling method based on drone photogrammetry described in the embodiment of the present application.

[0161] Test example

[0162] Taking the slope of a waste dump as an example, the slope formed by graded stacking is clearly stepped, and the graded slope height and step width are within 10 meters, the slope is not greater than 30°, and the micro-geomorphological features are obvious. The aerial panoramic view of the slope of the waste dump is as follows: Figure 4 As shown in the figure, the close-up view of the slag slope of the abandoned soil field is as follows: Figure 5 The measured cross-section of the slag slope of the waste dump is shown in Figure 6 shown.

[0163] This test case provides a fast and refined three-dimensional numerical modeling method based on UAV photogrammetry, including the following steps:

[0164] Step 1. In Rhinoceros, click "File (F) → Import (I)", select "Supported file types (*.*)" as OBJ (*.obj), and import the original real-life 3D model (see Figure 2 ) into Rhinoceros to obtain the first native 3D mesh (see Figure 3 );

[0165] Step 2: Using the intercepting drainage ditch surrounding the spoil dump slope as the boundary, draw the scope of the spoil dump slope in AutoCAD software, import it into Rhinoceros in ".dxf" format, and cut out the spoil dump slope range grid A based on the boundary imported into Rhinoceros. Figure 7 , Figure 7 The three-dimensional grid A is used to cut out the range of the slag slope;

[0166] Step 3: Import the original real-life 3D model into Rhinoceros to obtain the second original 3D mesh. Process the second original 3D mesh. It can be seen that the number of grids in the second original 3D mesh is more than 6 million. In places with more vegetation, the grid appears very messy, and there are sharp "spikes" in some places. Since the terrain outside the slope is not the focus of numerical simulation, it should be simplified and smoothed. Click "Mesh (M) → Edit Tool (E) → Reduce Mesh (R)" to reduce the mesh. In this test example, the mesh is reduced from more than 6 million to about 50,000 by reducing the mesh in batches. See Figure 8 , Figure 8 The second native 3D mesh after the reduction process (about 50,000); click "Subdivision Object (U) → Edit Tool (E) → Reconstruct Mesh with Quadrilaterals (Q)", and reconstruct the mesh using "10m × 10m" quadrilaterals to further improve the smoothness, and obtain the 3D mesh B of the terrain surface after quadrilateral reconstruction, see Fig. 9 , Fig. 9 The three-dimensional mesh B of the terrain surface after quadrilateral reconstruction;

[0167] Step 4: Open Grid A and Grid B, and make sure that all Grid B is below Grid A within the range of the spoil dump slope by manual inspection and adjustment. Fig.10 , Fig.10 This is the image after grid A and grid B are superimposed;

[0168] Step 5. Switch the Rhinoceros view to "Top", click "Surface (C) → Curtain (P)", set the control point spacing value, select the range of Grid A + Grid B, and generate the surface with curtain ( Fig.11 ). In this step, different control point spacing values ​​may be tried. In this test case, the control point spacing value finally determined is 2 meters × 2 meters to achieve the effect that best reflects the micro-topography of the slope. Fig.11 Surface plot generated for the drapery;

[0169] Step 6. Click "Mesh (M) → From NURBS Object (F)" to convert the surface into a mesh. According to the field survey, the scope of the proposed model is obtained, and the proposed modeling range is trimmed to obtain the final three-dimensional terrain, that is, mesh C ( Fig.12 ), Fig.12 is the three-dimensional terrain, i.e., grid C;

[0170] Step 7: The method for obtaining a watertight three-dimensional model includes:

[0171] On the basis of the grid C, the slope surface and slope bottom of the three-dimensional model are constructed;

[0172] Construct the terrain surface around the slope in the 3D model;

[0173] Construct the stratigraphic interface within the scope of the 3D model, which is generally formed based on relevant geological data using tools such as "sweep" and "split";

[0174] Build the base of the three-dimensional model;

[0175] The above parts are combined together to obtain a watertight three-dimensional model.

[0176] The construction process of the three-dimensional watertight model is as follows Figure 13~Figure 18 As shown, Fig.13 The surface of the slope of the spoil dump; Fig.14 It is the bottom surface of the slope of the spoil dump; Fig.15 It is the terrain surface around the slope of the spoil dump;

[0177] Fig.16 It is the stratigraphic interface within the 3D model; Fig.17 It is the base of the three-dimensional model; Fig.18 A complete three-dimensional model.

[0178] Step 8: Use the Griddle plug-in in Rhinoceros to mesh the 3D model and obtain a 3D numerical model (the meshing accuracy of the slope part is about 2 meters) for numerical simulation ( Fig.19 ), Fig.19 It is a gridded three-dimensional numerical model.

[0179] The generated 3D numerical model can not only be used for numerical analysis in ITASCA series software, but also supports import into other numerical simulation platforms such as ANSYS and ABAQUS ( Figure 20~Figure 23 ), Fig. 20 Import FLAC for 3D numerical models 3D ,3DEC diagram; Fig.21 Import diagrams of other numerical simulation platforms (ABAQUS, ANSYS) for 3D numerical models; Fig. 22 for FLAC 3D Model calculation result cloud diagram (overall); Fig.23 for FLAC 3D Cloud diagram of calculation results for the main section of the model.

[0180] 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 and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A fast and refined three-dimensional numerical modeling method based on UAV photogrammetry, It is characterized in that include: Import the original real-life 3D model into Rhinoceros to obtain the first original 3D mesh; The first native three-dimensional grid is clipped to obtain a three-dimensional grid A in the slope range; The original real-scene 3D model is imported into Rhinoceros again to obtain a second original 3D mesh, and the second original 3D mesh is reduced and quadrilateralized to obtain a 3D mesh B of the terrain surface; Open Grid A and Grid B, so that all Grid B is under Grid A; Select the range of mesh A and mesh B, and the curtain will generate the surface; Convert the surface into a mesh to obtain the final three-dimensional terrain, i.e., mesh C; On the basis of the grid C, the slope surface, slope bottom, terrain surface around the slope, stratum interface and base of the three-dimensional model are constructed and combined together to obtain a watertight three-dimensional model; The three-dimensional model is meshed to obtain a three-dimensional numerical model.

2. The method for rapidly refining three-dimensional numerical modeling based on drone photogrammetry according to claim 1, It is characterized in that Native real-world 3D models in .obj format; and / or The slope includes a landslide or a side slope.

3. The method for rapid and refined three-dimensional numerical modeling based on drone photogrammetry according to claim 1, It is characterized in that The native real-scene 3D model is obtained through photogrammetry of drones and then 3D reconstruction using 3D real-scene modeling software. The 3D real-scene modeling software includes one or more of DJI Zhitu, Context Capture, and Pix4D.

4. The method for rapidly refining three-dimensional numerical modeling based on drone photogrammetry according to claim 1, It is characterized in that According to the slope range obtained from the field survey, the slope range is outlined in AutoCAD or ArcGIS software, saved in .dxf format and imported into Rhinoceros to crop out the three-dimensional grid A of the slope range.

5. The method for rapidly and finely modeling a three-dimensional numerical model based on drone photogrammetry according to claim 1, It is characterized in that Convert the surface into a grid, obtain the scope of the proposed model based on the field survey, cut the scope of the proposed model, and obtain the final three-dimensional terrain, namely grid C.

6. The method for rapidly refining three-dimensional numerical modeling based on drone photogrammetry according to claim 1, It is characterized in that The Griddle plug-in is used in Rhinoceros to mesh the three-dimensional model and obtain a three-dimensional numerical model.

7. Rapid and refined three-dimensional numerical modeling system based on drone photogrammetry, It is characterized in that include: Import module, used to import the original real-life 3D model into Rhinoceros to obtain the first original 3D mesh; A clipping module, used for clipping the first native three-dimensional grid to obtain a three-dimensional grid A in a slope range; The reduction and quadrilateral reconstruction module is used to import the original real-scene 3D model into Rhinoceros again to obtain a second original 3D mesh, and to reduce and quadrilateralize the second original 3D mesh to obtain a 3D mesh B of the terrain surface; Overlay module, open grid A and grid B, so that all grid B is under grid A; In the curtain surface generation module, select the range of mesh A and mesh B to generate the curtain surface; The surface-to-grid module is used to convert the surface into a grid to obtain the final three-dimensional terrain, i.e., the grid C; Construct a watertight three-dimensional model module. On the basis of the grid C, construct the slope surface, slope bottom, terrain surface around the slope, stratum interface and base of the three-dimensional model, and combine them together to obtain a watertight three-dimensional model. The meshing module is used to mesh the three-dimensional model to obtain a three-dimensional numerical model.

8. Computer equipment, It is characterized in that The invention comprises a storage and a processor, wherein the storage 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 6.

9. Computer readable storage medium, It is 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 6.

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