Active fracture outcrop three-dimensional modeling system

Abstract

The invention provides an active fracture outcrop three-dimensional modeling system, and relates to the field of field geological work. The active fracture outcrop three-dimensional modeling system comprises a smart phone and an intelligent marking nail, and the smart phone comprises a sensor module, a data processing module, an interaction module, an RTK high-precision positioning module and a multispectral camera module; the smart phone has the functions that the RTK high-precision positioning module can realize high-precision positioning after being connected through Bluetooth; a multispectral camera module can better restore the trueness of the image; the intelligent marking nails are used for marking faults and various marker layers; the intelligent marking nail and the intelligent mobile phone are used for identifying the marking nail and reconstructing a three-dimensional geologic model. The transportation problem in a field hard environment can be solved through light and easy carrying, and the device is suitable for a field operation environment with a small number of personnel; available data models can be quickly generated on site, and timely correction is facilitated; meanwhile, cost is relatively low, and popularization is convenient.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of field geological work, in particular to a three-dimensional modeling system for active fault outcrop. BACKGROUND

[0002] The dislocation measurement and active rate calculation of active fault zone are one of the core research contents of structural geology, engineering geology and related geological disaster prevention. The traditional geological survey method mainly relies on manual carrying of measuring tools (such as compass and tape) and manual recording, which has problems of high dependence on operator experience, low efficiency and lack of three-dimensional information. In recent years, with the development of digital mapping, computer vision and augmented reality (AR) technology, geological outcrop investigation gradually develops towards digitization, intelligentization and visualization, but still faces many technical bottlenecks, and various methods also have the disadvantages of high cost and low efficiency.

[0003] Prior art solutions: 1. Traditional manual measurement: using a compass to measure the occurrence of a fault in the field, and recording it on a field notebook, and then drawing a profile in the room by using arcgis software. 2. Laser scanner measurement method: using ground LiDAR to scan the outcrop to directly obtain a centimeter-level precision three-dimensional model. 3. UAV photogrammetry method: taking high-definition photos of the outcrop by using a UAV, and processing them by using professional modeling software such as Context Capture.

[0004] Disadvantages of prior art:

[0005] 1. Disadvantages of traditional manual measurement: low efficiency, it may take 2-3 days to draw a single outcrop, and it cannot obtain three-dimensional geometric information, highly depends on the experience of the staff, and the information restoration degree is relatively low.

[0006] 2. Disadvantages of laser scanner measurement method: high equipment cost, tens of thousands of yuan are needed for purchase, and the equipment is heavy and precise, the damage rate during field transportation is more than 20%, which is not suitable for long-distance transportation in complex field terrain.

[0007] 3. Disadvantages of UAV photogrammetry method: the image accuracy in high-vegetation-covered areas will decrease significantly, professional workstations are needed for data processing (time-consuming > 1 hour), real-time interaction is not available, the collected data needs to be reworked in the field, and there may be airspace restrictions and flight bans. SUMMARY

[0008] (1) Technical problems solved

[0009] In view of the deficiencies of the prior art, the present application provides a three-dimensional modeling system for active fault outcrop, which solves the problems of low efficiency of traditional manual measurement, high equipment cost of laser scanner measurement and significant decrease of image accuracy in high-vegetation-covered areas of UAV photogrammetry method.

[0010] (II) Technical Solution

[0011] To achieve the above object, the application is implemented by the following technical solution: a three-dimensional modeling system for active fault outcrop, comprising a smart phone and a smart marker spike, the smart phone comprising a sensor module, a data processing module, an interaction module, an RTK high-precision positioning module and a multi-spectrum camera module.

[0012] The functions of the smart phone are as follows: the RTK high-precision positioning module can realize high-precision positioning through Bluetooth connection; the multi-spectrum camera module can better restore the authenticity of images.

[0013] The functions of the smart marker spike are as follows: used for marking faults and various marker layers.

[0014] The functions of the smart marker spike and the smart phone are as follows: used for identifying the marker spike and reconstructing a three-dimensional geological model, and used for constructing a three-dimensional model in real time through a SLAM algorithm constrained by the marker spike.

[0015] The smart marker spike further comprises a top marker layer, a magnetic fixing layer and an information storage chip, the outer surface of the smart marker spike is provided with a plurality of arc-shaped mounting grooves, the outer part of the arc-shaped mounting grooves is provided with a color-coded ring, a threaded hole is provided between the middle part of the color-coded ring and the smart marker spike, a bolt penetrates through the inside of the threaded hole, the top end of the smart marker spike is fixedly connected with the top marker layer, the inside top end of the smart marker spike is fixedly connected with the magnetic fixing layer, the bottom end of the magnetic fixing layer is fixedly connected with a bottom contact layer, and the bottom end of the bottom contact layer is fixedly connected with the information storage chip.

[0016] Preferably, the smart marker spike is a hollow ABS shell.

[0017] Preferably, the bottom contact layer is made of 304 stainless steel material with a hardness of HRC28.

[0018] Preferably, the smart marker spike is a fixed landmark with known coordinates, abnormal matching points are removed through a RANSAC algorithm, the pose estimation accuracy is optimized, in Ground-SLAM and other algorithms, the marker spike can be modeled as an infinite plane constraint, and the cumulative drift of a laser radar is reduced through pose graph optimization.

[0019] Preferably, the functions of the multi-spectrum camera module are as follows: through visible light and near-infrared multi-band data fusion, the robustness of feature point detection of the marker spike in a complex environment such as soil layer reflection or vegetation shielding is improved, the near-infrared band can penetrate the surface interference, and the geometric features of the marker spike are stably extracted.

[0020] Preferably, the RTK high-precision positioning module functions as: when the marker peg cannot be detected due to soil layer obstruction or light change, the loose combination navigation system composed of RTK and IMU can maintain short-term positioning continuity, and avoids modeling interruption.

[0021] Preferably, the interaction module in the smart phone functions as: the layered display of the model can be controlled, and the user can understand the complex structure.

[0022] Preferably, the sensor module is divided into: a visual sensor, a global sensor and an intelligent marker peg identification module.

[0023] (Three) beneficial effects

[0024] The application provides a three-dimensional modeling system for active fault outcrop.

[0025] 1. The application is portable and can solve the transportation problem in harsh outdoor environments, is suitable for a small number of personnel in the field, can quickly generate a data model on site, is convenient for timely correction, and has a relatively low cost and is easy to popularize.

[0026] 2. The system uses the SLAM technology of the marker peg constraint to improve the positioning accuracy to the centimeter level. Compared with the traditional method, the modeling scheme has the advantages of high efficiency, low cost, high precision, strong environmental adaptability and simple operation, and can be widely used in the fields of geological survey and disaster monitoring. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 FIG. 1 is a three-dimensional structure diagram of the intelligent marker peg of the three-dimensional modeling system for active fault outcrop;

[0028] Figure 2 FIG. 2 is a sectional front view of the three-dimensional modeling system for active fault outcrop;

[0029] Figure 3 FIG. 3 is a split structure diagram of the color coding ring and the intelligent marker peg of the three-dimensional modeling system for active fault outcrop;

[0030] Figure 4 FIG. 4 is a flowchart of the three-dimensional modeling system for active fault outcrop.

[0031] 1, intelligent marker peg; 2, color coding ring; 3, top marker layer; 4, magnetic fixing layer; 5, bottom contact layer; 6, information storage chip; 7, arc-shaped mounting groove; 8, threaded hole; 9, bolt. DETAILED DESCRIPTION

[0032] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0033] Example 1:

[0034] like Figures 1-4 As shown, an embodiment of the present invention provides: a 3D modeling system for active fault outcrops, comprising: a smart phone and a smart marker, wherein the smart phone comprises a sensor module, a data processing module, an interaction module, an RTK high-precision positioning module and a multispectral camera module, and the smart marker serves as a fixed landmark with known coordinates. The RANSAC algorithm is used to remove abnormal matching points, optimize the pose estimation accuracy, extract point cloud features and establish an initial matching relationship; then, a minimum point set (such as 4 pairs of points) is randomly selected to calculate a geometric transformation model, and inliers are selected based on the projection error (the threshold is usually 1-3 times the point cloud resolution); and iterations are repeated until the optimal model is obtained (the inlier ratio is greater than 95% or reaches 50 0-1000 iterations), the final retained inliers are used to accurately estimate the geometric parameters of the fracture surface, effectively eliminating interference such as vegetation occlusion and data loss, and ensuring the topological accuracy of the 3D model. This algorithm is particularly suitable for matching optimization of complex structures such as strike-slip faults. In algorithms such as Ground-SLAM, marker pins can be modeled as infinite plane constraints, and the cumulative drift of the lidar can be reduced through pose graph optimization. The role of the multispectral camera module is to improve the robustness of feature point detection of marker pins in complex environments such as soil reflection or vegetation occlusion by fusing visible light and near-infrared multi-band data. The near-infrared band can penetrate surface interference and stably extract the geometric features of the marker pins.

[0035] The smartphone's RTK high-precision positioning module enables high-precision positioning via Bluetooth connection. The multispectral camera module can better restore the realism of the image. The RTK high-precision positioning module's function is to maintain short-term positioning continuity when the marker pins are blocked by soil or light changes, and avoid modeling interruptions through the loosely integrated navigation system composed of RTK and IMU.

[0036] The smart marker pins are used to mark the fault itself and various marker layers. The interactive module in the smartphone controls the layered display of the model, helping users understand complex structures.

[0037] The functions of the intelligent marker peg and the smart phone are: used for identifying the marker peg and reconstructing a three-dimensional geological model, a three-dimensional model is constructed in real time through a SLAM algorithm constrained by the marker peg, and the sensor module is divided into: a visual sensor, a global sensor and an intelligent marker peg identification module.

[0038] Embodiment two:

[0039] The difference between this embodiment and embodiment one is that the active fault outcrop three-dimensional modeling system comprises: the intelligent marker peg 1 further comprises: a top marker layer 3, a magnetic fixing layer 4 and an information storage chip 6, a plurality of arc-shaped mounting grooves 7 are formed in the outer surface of the intelligent marker peg 1, a color coding ring 2 is sleeved outside the arc-shaped mounting grooves 7, the color coding ring 2 is divided into three colors of red, yellow and blue, the gravel layer is red, the coarse sand layer is yellow, and the fine sand layer is blue, which can assist in quickly identifying the stratum properties of the fault dislocation on site, a threaded hole 8 is formed between the middle of the color coding ring 2 and the intelligent marker peg 1, a bolt 9 penetrates through the inside of the threaded hole 8, the top end of the intelligent marker peg 1 is fixedly connected with the top marker layer 3, the inside top end of the intelligent marker peg 1 is fixedly connected with the magnetic fixing layer 4, the bottom end of the magnetic fixing layer 4 is fixedly connected with a bottom contact layer 5, the bottom contact layer 5 is made of 304 stainless steel material, the hardness is HRC28, the bottom end of the bottom contact layer 5 is fixedly connected with the information storage chip 6, and the intelligent marker peg 1 is a hollow ABS shell.

[0040] Working principle: in use, the top marker layer 3 uses the color coding ring 2, uses wear-resistant PVC material, and can be color-coated and marked, is used for distinguishing various strata, and ensures the recognition degree under poor light conditions; the intelligent marker peg 1 uses a hollow ABS shell, has waterproof function for protecting the internal information storage chip 6; the magnetic fixing layer 4 uses an N52 grade magnet, is used for connecting the bottom contact layer 5, and is used for driving the intelligent marker peg 1 into the soil body or rock body; the information storage chip 6 uses an NFC chip, an NTAG213 chip, has a storage capacity of 144 bytes, and is used for recording stratum information.

[0041] Although the embodiments of the present application have been shown and described, it can be understood by those skilled in the art that various changes, modifications, replacements and variations can be made to the embodiments without departing from the principles and spirits of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A three-dimensional modeling system for active fault outcrops, comprising: A smart phone and a smart marking nail, characterized in that the smart phone includes a sensor module, a data processing module, an interaction module, an RTK high-precision positioning module and a multispectral camera module; The smartphone has the following functions: the RTK high-precision positioning module can achieve high-precision positioning after being connected via Bluetooth; the multi-spectral camera module can better restore the authenticity of the image; The function of the intelligent marking nail is to mark the fault itself and various marker layers; The functions of the smart marker and the smart phone are: to identify the marker and reconstruct the three-dimensional geological model, and to construct the three-dimensional model in real time through the SLAM algorithm constrained by the marker; The smart marking nail (1) further comprises: a top marking layer (3), a magnetic fixing layer (4) and an information storage chip (6); the outer surface of the smart marking nail (1) is provided with a plurality of arc-shaped mounting grooves (7); the outer surface of the arc-shaped mounting groove (7) is provided with a color coding ring (2); a threaded hole (8) is provided between the middle of the color coding ring (2) and the smart marking nail (1); a bolt (9) is passed through the inside of the threaded hole (8); the top end of the smart marking nail (1) is fixedly connected to the top marking layer (3); the inner top end of the smart marking nail (1) is fixedly connected to the magnetic fixing layer (4); the bottom end of the magnetic fixing layer (4) is fixedly connected to the bottom contact layer (5); and the bottom end of the bottom contact layer (5) is fixedly connected to the information storage chip (6).

2. The active fracture outcrop 3D modeling system according to claim 1, characterized in that: The smart marking nail (1) is a hollow ABS shell.

3. The active fracture outcrop 3D modeling system according to claim 1, characterized in that: The bottom contact layer (5) is made of 304 stainless steel with a hardness of HRC28.

4. The active fracture outcrop 3D modeling system according to claim 1, characterized in that: The smart marker serves as a fixed landmark with known coordinates. The RANSAC algorithm is used to eliminate abnormal matching points and optimize the accuracy of pose estimation. In algorithms such as Ground-SLAM, the marker can be modeled as an infinite plane constraint, and the cumulative drift of the lidar can be reduced through pose graph optimization.

5. The active fracture outcrop 3D modeling system according to claim 1, characterized in that: The function of the multispectral camera module is to improve the robustness of feature point detection of marker nails in complex environments such as soil reflection or vegetation occlusion by fusing visible light and near-infrared multi-band data. The near-infrared band can penetrate surface interference and stably extract the geometric features of the marker nails.

6. The active fracture outcrop 3D modeling system according to claim 1, characterized in that: The function of the RTK high-precision positioning module is: when the marker pins cannot be detected due to soil obstruction or light changes, the loose integrated navigation system composed of RTK and IMU can maintain short-term positioning continuity and avoid modeling interruption.

7. The active fracture outcrop 3D modeling system according to claim 1, characterized in that: The function of the interactive module in the smart phone is to control the hierarchical display of the model and assist the user in understanding the complex structure.

8. The active fracture outcrop 3D modeling system according to claim 1, characterized in that: The sensor module is divided into: a visual sensor, a global sensor and an intelligent marking nail recognition module.

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