Drilling hole internal three-dimensional model construction method and system based on point cloud ring constraint

Abstract

The disclosure provides a borehole internal three-dimensional model construction method and system based on point cloud ring constraint, relates to the technical field of borehole three-dimensional modeling, and comprises the following steps: controlling laser probe rotation and advancement, and acquiring borehole profile information sequences at each section; acquiring borehole profile coordinate sequences at different sections in the borehole based on the borehole profile information sequences of each section; generating a standardized three-dimensional point cloud sequence based on the borehole profile coordinate sequences; generating a continuous surface model based on the standardized three-dimensional point cloud sequence, performing constraint Delaunay triangulation on each layer of annular point cloud of the continuous surface model, forcibly closing the ring constraint, generating a longitudinal triangular strip grid, and completing the construction of the borehole three-dimensional model. The method disclosed by the disclosure can intuitively display the pores or fissures in the borehole.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of borehole three-dimensional modeling, in particular to a borehole internal three-dimensional model construction method and system based on point cloud ring constraint. BACKGROUND

[0002] The statements in this section merely provide background information related to the present disclosure and do not necessarily constitute the prior art.

[0003] In underground engineering such as tunnels and mining, the integrity of the surrounding rock can be understood through drilling. According to the number and location of cracks, pores and fracture zones in the borehole, potential safety hazards during construction can be detected in time, so that appropriate preventive and disposal measures can be taken in time. This helps to avoid engineering accidents, protect personnel and equipment safety, and improve construction efficiency.

[0004] Traditionally, the internal situation of the borehole is observed by drilling peering, a long rod is used to push a high-definition camera to the deep part of the borehole and record the video, and personnel need to understand the integrity of the internal surrounding rock through the borehole video. This method has limitations and inconvenience. The light in the borehole is dim, and a camera light needs to be used for exploration. At this time, the reflection of the rock surface will affect the judgment of the technician. When observing a long borehole, the video time is too long, and the technician may miss important geological information during a long observation.

[0005] Currently, most three-dimensional modeling methods based on digital twinning rely on high-precision equipment. These devices have high use cost, large size and poor environmental adaptability, and are not convenient to deploy in the complex and variable construction site of the tunnel. Moreover, the traditional three-dimensional modeling technology needs to process a large amount of data and involves a series of operations such as denoising, splicing and enhancement, which leads to a long model reconstruction period in the post-processing scheme, thereby requiring high performance of the computing device. SUMMARY

[0006] To solve the above problems, the present disclosure provides a borehole internal three-dimensional model construction method and system based on point cloud ring constraint. The internal shape information of the borehole is obtained by laser ranging, the contour distance information of each section in the borehole is obtained, the standardized three-dimensional point cloud sequence is generated according to the borehole information sequence at each distance, the discrete point cloud is converted into a continuous surface model, the constraint Delaunay triangulation is performed on each layer of annular point cloud, the ring constraint is forced to be closed, the longitudinal triangular strip grid is generated, and the borehole three-dimensional model is constructed.

[0007] According to some embodiments, the present disclosure adopts the following technical solutions:

[0008] The borehole internal three-dimensional model construction method based on point cloud ring constraint comprises:

[0009] acquire a starting position, a starting angle and a distance corresponding to the starting angle of the laser probe in the borehole, and generate an initial borehole profile information sequence;

[0010] control the rotation of the laser probe, acquire an angle of rotation of the laser probe and a measured distance at the angle, generate a current borehole profile information sequence based on the initial borehole profile information sequence, the angle of current rotation and the measured distance at the angle, and control the laser probe to rotate deeper into the borehole, thereby generating a borehole profile information sequence at each position;

[0011] acquire borehole profile coordinate sequences at different cross sections in the borehole based on the borehole profile information sequences at each position, and generate a standardized three-dimensional point cloud sequence based on the borehole profile coordinate sequences;

[0012] generate a continuous surface model based on the standardized three-dimensional point cloud sequence, perform constrained Delaunay triangulation on each layer of annular point cloud of the continuous surface model, enforce a closed loop constraint, generate a longitudinal triangular strip mesh, and complete the construction of the three-dimensional model of the borehole.

[0013] According to some embodiments, the present disclosure adopts the technical solutions as follows:

[0014] A borehole internal three-dimensional model construction system based on point cloud ring constraint comprises:

[0015] An initialization module is configured to acquire a starting position, a starting angle and a distance corresponding to the starting angle of the laser probe in the borehole, and generate an initial borehole profile information sequence;

[0016] A sequence acquisition module is configured to control the rotation of the laser probe, acquire an angle of rotation of the laser probe and a measured distance at the angle, generate a current borehole profile information sequence based on the initial borehole profile information sequence, the angle of current rotation and the measured distance at the angle, and control the laser probe to rotate deeper into the borehole, thereby generating a borehole profile information sequence at each position;

[0017] A point cloud processing module is configured to acquire borehole profile coordinate sequences at different cross sections in the borehole based on the borehole profile information sequences at each position, and generate a standardized three-dimensional point cloud sequence based on the borehole profile coordinate sequences;

[0018] A model generation module is configured to generate a continuous surface model based on the standardized three-dimensional point cloud sequence, perform constrained Delaunay triangulation on each layer of annular point cloud of the continuous surface model, enforce a closed loop constraint, generate a longitudinal triangular strip mesh, and complete the construction of the three-dimensional model of the borehole.

[0019] According to some embodiments, the present disclosure adopts the technical solutions as follows:

[0020] The computer program product comprises a computer program, and the computer program is executed by a processor to implement the method for constructing a three-dimensional model of a borehole interior based on point cloud ring constraints.

[0021] According to some embodiments, the present disclosure adopts the technical scheme as follows:

[0022] A non-transitory computer-readable storage medium is configured to store computer instructions, and the computer instructions are executed by a processor to implement the method for constructing a three-dimensional model of a borehole interior based on point cloud ring constraints.

[0023] According to some embodiments, the present disclosure adopts the technical scheme as follows:

[0024] An electronic device comprises a processor, a memory, and a computer program, wherein the processor is connected with the memory, and the computer program is stored in the memory; when the electronic device is running, the processor executes the computer program stored in the memory, so that the electronic device implements the method for constructing a three-dimensional model of a borehole interior based on point cloud ring constraints.

[0025] Compared with the prior art, the present disclosure has the beneficial effects as follows:

[0026] The method for constructing a three-dimensional model of a borehole interior based on point cloud ring constraints of the present disclosure acquires point cloud data in the borehole interior through laser ranging technology, reduces the volume of the detection instrument, and simplifies the borehole detection and data processing process.

[0027] The method for constructing a three-dimensional model of a borehole interior based on point cloud ring constraints of the present disclosure can accurately collect point cloud data in a narrow borehole, and quickly construct a three-dimensional model of the borehole through a Delaunay triangulation algorithm without relying on a large amount of computing resources. The model can accurately and intuitively show the surrounding rock conditions in the borehole, which is helpful for technicians to analyze the distribution of cracks and fractured zones in the borehole.

[0028] The method for constructing a three-dimensional model of a borehole interior based on point cloud ring constraints of the present disclosure is suitable for three-dimensional form reconstruction of small-diameter (Φ50-150mm) boreholes such as coal mine gas extraction holes, roadway and tunnel support quality detection holes, and can be compatible with various borehole types such as vertical holes and inclined holes. BRIEF DESCRIPTION OF DRAWINGS

[0029] The drawings accompanying the specification of the present disclosure serve to provide a further understanding of the present disclosure, and the illustrative embodiments of the present disclosure and their descriptions serve to explain the present disclosure, and do not constitute improper limitations on the present disclosure.

[0030] Figure 1 The single-layer cross-section scanning result of the embodiment of the present disclosure;

[0031] Figure 2 A three-dimensional model of a borehole according to an embodiment of the present disclosure;

[0032] Figure 3 A schematic diagram of a laser probe scanning a borehole according to an embodiment of the present disclosure;

[0033] Figure 4 A flowchart of a method for constructing a three-dimensional model of the interior of a borehole based on point cloud ring constraints according to an embodiment of the present disclosure.

[0034] Wherein, 1, a splicable long rod; 2, a sliding support frame; 3, borehole surrounding rock; 4, a laser ranging probe; 5, a rotating device. DETAILED DESCRIPTION

[0035] The present disclosure will be further described below in conjunction with the accompanying drawings and embodiments.

[0036] It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the present disclosure. Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present disclosure belongs.

[0037] It should be noted that the terms used herein are merely for the purpose of describing specific embodiments and are not intended to limit exemplary embodiments according to the present disclosure. As used herein, the singular form is intended to include the plural form unless the context clearly indicates otherwise, and it should also be understood that when the terms "comprise" and / or "include" are used in this specification, there is a presence of the features, steps, operations, devices, components, and / or combinations thereof.

[0038] Embodiment 1

[0039] The method for constructing a three-dimensional model of the interior of a borehole based on point cloud ring constraints according to the present disclosure obtains the internal form information of the borehole by laser ranging, constructs a three-dimensional model of the borehole, and can intuitively display the pores or fissures in the borehole. The method steps include:

[0040] Step 1: Obtain the starting position, starting angle, and distance corresponding to the starting angle of the laser probe in the borehole, and generate an initial borehole profile information sequence;

[0041] Step 2: Control the laser probe to rotate and obtain the angle of rotation of the laser probe and the measured distance at that angle; based on the initial borehole profile information sequence, the current angle of rotation, and the measured distance at that angle, generate a borehole profile information sequence under 360 degrees of rotation of the current cross section; control the laser probe to rotate continuously into the borehole, thereby generating a borehole profile information sequence under 360 degrees of rotation of each cross section;

[0042] Step 3: Obtain the borehole profile coordinate sequence at different sections inside the borehole based on the borehole profile information sequence of each section; and generate a standardized three-dimensional point cloud sequence based on the borehole profile coordinate sequence;

[0043] Step 4: Generate a continuous surface model based on the standardized three-dimensional point cloud sequence, perform constrained Delaunay triangulation on each layer of annular point cloud of the continuous surface model, and generate a longitudinal triangular strip grid by forcing the closed ring constraint, thereby completing the construction of the three-dimensional model of the borehole.

[0044] As an embodiment, the specific implementation process of the borehole internal three-dimensional model construction method based on point cloud ring constraint of the present disclosure includes:

[0045] Step 1: Obtain the starting position, starting angle and distance corresponding to the starting angle of the laser probe in the borehole, and generate the borehole profile information sequence of the initial section;

[0046] Specifically, as shown in Figure 3 , the laser probe 4 is fixed on the splicable long rod 1, the splicable long rod 1 with the laser probe 4 is inserted into the borehole surrounding rock 3, the laser probe 4 is fixed at the center position of the borehole surrounding rock 3 through the sliding support frame 2, and the initial section is recorded as x 0. The laser ranging module is turned on to start distance measurement, the starting angle θ 00 and the distance corresponding to the angle r 00 at this time are recorded, then the laser probe is rotated, and the angle θ 0 i and the measured distance r 0 i of the laser probe at the angle are recorded.

[0047] The rotating device 5 is used to control the rotation of the laser probe 4, and the angle of rotation of the laser probe 4 and the measured distance at the angle are obtained; the current borehole profile information sequence is generated based on the initial borehole profile information sequence, the angle of rotation and the measured distance at the angle, including:

[0048] In the future, when the probe is rotated, the distance information is recorded once every 1° of rotation, and the borehole profile information sequence at the 0 section is recorded x 0, x 0 θ 0 i , r 0 i , the borehole profile information sequence of the initial section is x 0, θ 00, r 00]-[ x 0, θ 0359, r0359].

[0049] As one embodiment, the aforementioned laser probe employs a pulsed laser sensor to acquire spatial distance information of the borehole inner wall, performing a 360° rotation scan at 1° intervals to generate a polar coordinate data sequence. r , θ The probe completes a full circumference scan every 1cm of depth. The axial rotation drive unit has a built-in stepper motor (±0.5° accuracy) that drives the probe to rotate at a constant speed.

[0050] Step 2: Control the laser probe to rotate continuously and drill deeper into the hole, thereby generating a sequence of borehole contour information for each cross-section;

[0051] Specifically, the probe is pushed into the borehole at a constant speed using a modular, extendable rod. The pushing speed should not be too fast to ensure the laser rangefinder probe can rotate 360° at the same position and acquire distance information. In the direction of probe advancement, the borehole profile distance is measured at each cross-section every 1cm of advance. This allows for the acquisition of a sequence of borehole profile information at different cross-sections; for example, after advancing 1cm... x 1 is: [ x 1, θ 1 i , r 1 i [It has advanced another 1cm] x The two locations are: [ x 2, θ 2 i , r 2 i ], advancing multiple times x n The location is: [ x n , θ n i , r n i ].

[0052] Step 3: Obtain the borehole contour coordinate sequence at different cross-sections inside the borehole based on the borehole contour information sequence of each cross-section; generate a standardized 3D point cloud sequence based on the borehole contour coordinate sequence;

[0053] Specifically, based on the borehole information sequence at each cross-section, the rectangular coordinates of a ring of ranging points around each location are obtained, in order to... x Drilling profile information sequence at point 0 [ x 0, θ 0 i , r 0 i For example:

[0054]

[0055] wherein, y 0 i is x 0the horizontal axis coordinate of the contact point of the i-th laser ranging line with the borehole wall surface at the cross section; i z 0 i is x 0the vertical axis coordinate of the contact point of the i-th laser ranging line with the borehole wall surface at the cross section; i θ 0 i is x 0the angle between the i-th laser ranging line and the horizontal axis at the cross section; i i is the serial number of the laser ranging line, taking 0-359, and the angle between every two lines is 1 degree.

[0056] Finally, the borehole profile coordinate sequence at the cross section of 0 can be obtained, and the borehole profile coordinate sequences at the cross sections of 0- N can be obtained according to the same processing method. x x x N.

[0057] Further, the borehole internal rectangular coordinate system point cloud data is generated by layering according to the axial position xn , and the standardized three-dimensional point cloud sequence is generated in combination with the current position xn , and the point cloud data of each layer is:

[0058]

[0059] wherein, L n y n i is x n the horizontal axis coordinate of the contact point of the i-th laser ranging line with the borehole wall surface at the cross section, i n z n the vertical axis coordinate of the contact point of the i-th laser ranging line with the borehole wall surface at the cross section. i x i

[0060] Further, the borehole internal rectangular coordinate system point cloud data is generated by layering according to the axial position

[0061]

[0062] wherein, x ​​​​​​​​​n the number of layers for axial position, y n i the number of layers for axial position, x n the vertical axis coordinate of the contact point of the i-th laser ranging line with the borehole wall at the cross section, i the vertical axis coordinate of the contact point of the i-th laser ranging line with the borehole wall at the cross section, z n i the number of layers for axial position, x n the vertical axis coordinate of the contact point of the i-th laser ranging line with the borehole wall at the cross section, i the vertical axis coordinate of the contact point of the i-th laser ranging line with the borehole wall at the cross section, i the serial number of the laser ranging line, n a certain cross section, N the total number of cross sections.

[0063] Further, the discretized standardized three-dimensional point cloud sequence is converted into a continuous surface model, a Delaunay triangulation algorithm is used to construct a three-dimensional surface model, a single-layer cross section constraint Delaunay triangulation adds a mandatory edge constraint to ensure closed ends, the point set is projected onto a rectangular coordinate plane to generate two-dimensional scattered points, and the single-layer cross section model is formed after connection.

[0064] Specifically, the distance between adjacent layers is:

[0065]

[0066] wherein, x n the number of layers for axial position, x n+1 the number of layers for axial position, x n the cross section position of the next 1cm advancement of the cross section.

[0067] Delaunay triangulation algorithm is used to construct a three-dimensional surface model, a single-layer cross section constraint Delaunay triangulation adds a mandatory edge constraint to ensure closed ends:

[0068]

[0069] wherein, pi the two-dimensional scattered points.

[0070] the point set L n is projected onto y - z the plane to generate two-dimensional scattered points, and the single-layer cross section model is formed after connection, as shown inFigure 1 as shown.

[0071] Definition of adjacent layer point cloud L n with L n+1 same angle between θ correspondence of points:

[0072]

[0073] For each pair of adjacent points[ p n i , p n ( i +1), p (n+1) i , p (n+1) ( i +1)] generate quadrilaterals and split into two triangles:

[0074]

[0075] For all adjacent layer point clouds L n with L n+1 repeat the above operation, build a three-dimensional model of the borehole, as Figure 2 shown.

[0076] Finally, a human-computer interaction interface is provided for the three-dimensional model, supporting cross-section cutting, transparency adjustment, fissure highlight display, and measurement tools, real-time labeling of the distance between any two points, cross-sectional area, and other parameter comparison and analysis.

[0077] Embodiment 2

[0078] In an embodiment of the present disclosure, a point cloud ring constraint-based three-dimensional model construction system for the interior of a borehole is provided, comprising:

[0079] An initialization module is configured to obtain the starting position, starting angle, and distance corresponding to the starting angle of a laser probe in a borehole, and generate an initial borehole contour information sequence;

[0080] A sequence acquisition module is configured to control the rotation of the laser probe and obtain the angle of rotation of the laser probe and the measured distance at the angle; based on the initial borehole contour information sequence, the angle of the current rotation, and the measured distance at the angle, generate a borehole contour information sequence under the rotation of 360 degrees of the current cross section; control the laser probe to rotate continuously into the borehole, thereby generating a borehole contour information sequence under the rotation of 360 degrees of each cross section;

[0081] The point cloud processing module is configured to obtain a borehole profile coordinate sequence at different cross sections inside the borehole based on the borehole profile information sequence of each position; and generate a standardized three-dimensional point cloud sequence based on the borehole profile coordinate sequence.

[0082] The model generation module is configured to generate a continuous surface model based on the standardized three-dimensional point cloud sequence, perform constrained Delaunay triangulation on each layer of annular point cloud of the continuous surface model, generate a longitudinal triangular strip grid by forcing a closed ring constraint, and complete construction of the three-dimensional model of the borehole.

[0083] Embodiment 3

[0084] In an embodiment of the present disclosure, a computer program product is provided, comprising a computer program, which, when executed by a processor, implements the borehole internal three-dimensional model construction method based on point cloud ring constraint.

[0085] Embodiment 4

[0086] In an embodiment of the present disclosure, a non-transitory computer readable storage medium is provided, which is configured to store computer instructions, which, when executed by a processor, implement the borehole internal three-dimensional model construction method based on point cloud ring constraint.

[0087] Embodiment 5

[0088] In an embodiment of the present disclosure, an electronic device is provided, comprising a processor, a memory, and a computer program; wherein the processor is connected with the memory, and the computer program is stored in the memory; when the electronic device is running, the processor executes the computer program stored in the memory, so that the electronic device implements the borehole internal three-dimensional model construction method based on point cloud ring constraint.

[0089] The present disclosure is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present disclosure. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, and the combination of flows and / or blocks in the flowcharts and / or block diagrams can be implemented by computer program instructions. These computer program instructions can be provided to a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to produce a machine, so that the instructions executed by the computer or other programmable data processing devices produce a device that implements the functions specified in the flowcharts and / or block diagrams. Figure 1 The device that implements the functions specified in one flow or multiple flows and / or blocks Figure 1 The device that implements the functions specified in one flow or multiple flows and / or blocks

[0090] These computer program instructions can also be loaded into a computer or other programmable data processing devices, so that a series of operational steps are performed on the computer or other programmable data processing devices to generate a computer implemented process, so that the instructions executed on the computer or other programmable data processing devices provide a process for implementing the functions specified in the flowchart Figure 1 one flow or multiple flows and / or the functions specified in the block Figure 1 one flow or multiple flows and / or the functions specified in the block

[0091] Although the specific embodiments of the present disclosure are described above with reference to the drawings, the description is not a limitation on the scope of protection of the present disclosure, and those skilled in the art should understand that various modifications or changes made on the basis of the technical solutions of the present disclosure without creative labor are still within the scope of protection of the present disclosure.

Claims

1. A method for constructing a 3D model of borehole interior based on point cloud ring constraints, characterized in that, The method comprises the following steps: obtaining the starting position, starting angle and distance corresponding to the starting angle of the laser probe in the borehole, and generating an initial borehole profile information sequence; controlling the rotation of the laser probe, and obtaining the angle of rotation of the laser probe and the measured distance at the angle; based on the initial borehole profile information sequence, the current rotating angle and the measured distance at the angle, a borehole profile information sequence under the current cross section rotating 360 degrees is generated; the laser probe is continuously rotated and deepened into the borehole, and thus a borehole profile information sequence under the rotation of 360 degrees of each cross section is generated; based on the borehole profile information sequence of each cross section, a borehole profile coordinate sequence at different cross sections in the borehole is obtained; based on the borehole profile coordinate sequence, a standardized three-dimensional point cloud sequence is generated; based on the standardized three-dimensional point cloud sequence, a continuous surface model is generated, constrained Delaunay triangulation is performed on each layer of annular point cloud of the continuous surface model, a forced closed loop constraint is generated, a longitudinal triangular strip grid is generated, and the construction of the three-dimensional model of the borehole is completed, comprising: the discrete standardized three-dimensional point cloud sequence is converted into a continuous surface model, a three-dimensional surface model is constructed by using a Delaunay triangulation algorithm, a forced edge constraint is added to the single-layer cross-section constrained Delaunay triangulation to ensure the closed loop, the point set is projected onto a rectangular coordinate plane to generate a two-dimensional scattered point, and the single-layer cross-section model is formed after connection; the corresponding relationship of the points with the same angle between the adjacent layer point clouds and the point clouds is defined, a quadrilateral is generated for each pair of adjacent points and is split into two triangles, and the above operation is repeated between all adjacent layer point clouds and the point clouds to construct the three-dimensional model of the borehole. 2.The method of claim 1, wherein, The starting position, starting angle and distance corresponding to the starting angle of the laser probe in the borehole are acquired, and initial borehole profile information sequence is generated, including: placing the laser probe into the borehole, fixing the probe at the center position of the borehole, and recording the starting position x 0, recording the starting angle at this time θ 00 and the distance corresponding to the angle r 00, forming x 0 borehole profile information sequence at the cross section x 0, θ 0 i , r 0 i ]. 3.The method of claim 1, wherein, The laser probe is rotated, and an angle of rotation of the laser probe and a measured distance at the angle are obtained; a current borehole profile information sequence is generated based on an initial borehole profile information sequence, the angle of rotation and the measured distance at the angle, including: rotating the laser probe, recording the angle of rotation of the probe θ 0 i and the distance measured by the laser probe at the angle r 0 i At the time of rotation of the probe, the distance information is recorded once every 1° of rotation, and the current borehole profile information sequence is generated. 4.The method of claim 1, wherein, based on the borehole profile information sequence of each position, a borehole profile coordinate sequence at different cross sections in the borehole is obtained; based on the borehole profile coordinate sequence, a standardized three-dimensional point cloud sequence is generated, comprising: the rectangular coordinates of a circle of ranging points around each position are obtained according to the borehole profile information sequence of each position, comprising: Obtained x 0drilling profile coordinate sequence at the drilling position x 0, y 0i, z 0i), the drilling profile coordinate sequence of different sections inside the drilling is obtained according to the calculation method, the drilling inside the drilling is layered according to the axial position, the point cloud data of the rectangular coordinate system is generated, and the current position x The standardized three-dimensional point cloud sequence is generated.

5. A borehole interior 3D model construction system based on point cloud ring constraint, which specifically implements the borehole interior 3D model construction method based on point cloud ring constraint according to any one of claims 1-4, characterized in that, the initialization module is used for obtaining the starting position, starting angle and distance corresponding to the starting angle of the laser probe in the borehole, and generating an initial borehole profile information sequence; the sequence acquisition module is used for controlling the rotation of the laser probe, and obtaining the angle of rotation of the laser probe and the measured distance at the angle; based on the initial borehole profile information sequence, the current rotating angle and the measured distance at the angle, a borehole profile information sequence under the current cross section rotating 360 degrees is generated; the laser probe is continuously rotated and deepened into the borehole, and thus a borehole profile information sequence under the rotation of 360 degrees of each cross section is generated; the point cloud processing module is used for obtaining the borehole profile coordinate sequence at different cross sections in the borehole based on the borehole profile information sequence of each position; based on the borehole profile coordinate sequence, a standardized three-dimensional point cloud sequence is generated; the model generation module is used for generating a continuous surface model based on the standardized three-dimensional point cloud sequence, performing constrained Delaunay triangulation on each layer of annular point cloud of the continuous surface model, generating a forced closed loop constraint, generating a longitudinal triangular strip grid, and completing the construction of the three-dimensional model of the borehole. ​ 6. A computer program product comprising a computer program, characterized in that, The computer program is executed by a processor to implement the point cloud ring constraint based borehole internal three-dimensional model construction method in any one of claims 1-4.

7. A non-transitory computer-readable storage medium, comprising: The non-transitory computer readable storage medium is configured to store computer instructions, and the computer instructions are executed by a processor to implement the point cloud ring constraint based borehole internal three-dimensional model construction method in any one of claims 1-4.

8. An electronic device, comprising: Comprise: A processor, a memory and a computer program; wherein the processor is connected with the memory, and the computer program is stored in the memory; when the electronic device is running, the processor executes the computer program stored in the memory, so that the electronic device executes the point cloud ring constraint based borehole internal three-dimensional model construction method in any one of claims 1-4.

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