Blasthole positioning optimization method based on face point cloud constraint, medium and equipment

Abstract

This invention relates to the field of tunnel drilling and blasting technology, and particularly to a method, medium, and equipment for optimizing borehole placement based on face point cloud constraints. The method includes: scanning the tunnel face using a 3D lidar to obtain unmeshed face point cloud data in a local coordinate system; converting the face point cloud model to the absolute coordinate system of tunnel construction using a coordinate registration algorithm to obtain a 3D face point cloud model in absolute coordinates; constructing a reverse spatial linear equation for the borehole based on the coplanar constraint of the borehole bottom according to tunnel blasting design methods; and calculating the true borehole coordinates and actual borehole depth using a combination of spatial iterative search and local microplane fitting based on the 3D face point cloud model and the 3D borehole spatial trajectory equation. This invention can calculate the true borehole coordinates and actual borehole depth adaptable to uneven rock surfaces, solving the problems of uneven blasting foundations and severe over- and under-excavation.

Description

Technical Field

[0001] This invention relates to the field of tunnel drilling and blasting technology, and in particular to a method, medium, and equipment for optimizing borehole placement based on point cloud constraints at the tunnel face. Background Technology

[0002] Drill-and-blast method, a common construction method for tunnel excavation, requires determining the location and distribution of cut holes, auxiliary holes, and peripheral holes within the blast holes based on drilling and blasting parameters. Since subsequent drilling, charging, and blasting must be carried out according to the blast hole distribution map, the blast hole positions must be arranged on the excavation face before drilling. The accuracy of the blast hole arrangement directly affects the blasting quality during drill-and-blast construction.

[0003] Existing tunnel borehole design drawings are typically two-dimensional or three-dimensional layout diagrams based on an ideal plane, providing the absolute coordinates of the borehole openings on a standard cross-section. However, in actual construction, the tunnel face after blasting is often an uneven, irregular three-dimensional body. If boreholes are laid out and drilled on this uneven face solely according to the design coordinates of the ideal plane (i.e., maintaining a uniform drilling depth), the bottoms of each borehole will not be on the same vertical plane. Uneven borehole bottoms will severely affect the uniform distribution of blasting energy, leading to an even more uneven face in the next cycle, which in turn can cause over- or under-excavation of the surrounding rock mass, reducing construction efficiency and safety. With the development of LiDAR technology, it has become possible to acquire high-precision three-dimensional point cloud data of the tunnel face, providing data support for optimizing borehole layout based on the actual rock surface morphology.

[0004] Existing borehole placement techniques primarily employ manual placement or borehole projector placement. These methods allow for precise placement based on provided borehole design coordinates when the tunnel face is neither concave nor convex. However, tunnel faces are generally concave or convex, making it impossible for existing placement methods to accurately position the designed boreholes on the actual tunnel face. More importantly, existing methods neglect the impact of the tunnel face's unevenness on the requirement of "coplanar borehole bottoms." Blindly using the designed borehole depth for drilling leads to an uneven blasting foundation, poor blasting results, and increased difficulty in secondary hazard removal and muck removal.

[0005] Therefore, it is necessary to provide a new method, medium, and equipment for borehole placement optimization based on point cloud constraints at the tunnel face to solve the above-mentioned technical problems. Summary of the Invention

[0006] The main objective of this invention is to provide a method, medium, and device for optimizing borehole placement based on point cloud constraints at the working face, aiming to solve the problem that existing methods cannot accurately place the designed boreholes on the actual working face.

[0007] To achieve the above objectives, the present invention proposes a borehole placement optimization method based on point cloud constraints at the working face, comprising the following steps: The tunnel face was scanned using a 3D lidar to obtain unmeshed point cloud data of the face in a local coordinate system. The point cloud model of the face was then transformed into the absolute coordinate system of the tunnel construction using a coordinate registration algorithm, resulting in a 3D point cloud model of the face in absolute coordinates. Based on the tunnel blasting design method, the reverse spatial linear equation of the blast hole is constructed based on the coplanar constraint of the hole bottom; Based on the three-dimensional point cloud model of the working face and the three-dimensional spatial trajectory equation of the borehole, the actual borehole coordinates and actual borehole depth are calculated by combining spatial iterative search and local microplane fitting.

[0008] Optionally, the reverse spatial linear equation of the blast hole, constructed based on the coplanar constraint of the hole bottom according to the tunnel blasting design method, specifically includes: Obtaining the first from the tunnel blasting design scheme The absolute coordinates of the design boreholes. Design hole depth Horizontal angle and longitudinal angle ; Calculate the first based on the absolute coordinates of the designed orifice. The design of the absolute coordinates of the bottom of each borehole And according to the horizontal angle and longitudinal angle Define the direction vector of the borehole centerline. ; Starting from the absolute coordinates of the bottom of the borehole, extend along the borehole axis towards the borehole opening to construct the reverse spatial straight line equation of the borehole, as shown in the following expression: ; in: For the first The absolute coordinates of the bottom of each borehole are designed. This represents the actual spatial distance from a point on the trajectory line to the bottom of the hole, i.e., the potential actual drilling depth. .

[0009] Optionally, the first The design of the absolute coordinates of the bottom of each borehole The calculation formula is as follows: ; Specifically: when the centerline of the blast hole is located to the left of the tunnel excavation direction. A positive value occurs when the centerline of the blast hole is located to the right of the tunnel excavation direction. Negative values; longitudinal angle The value is positive when it is an elevation angle and negative when it is a depression angle; Direction vector of borehole centerline The specific expression is as follows: .

[0010] Optionally, based on the three-dimensional point cloud model of the working face and the three-dimensional spatial trajectory equation of the borehole, a method combining spatial iterative search and local microplane fitting is used to calculate the true borehole coordinates and the actual borehole depth, specifically including: ① Construct a KD-tree spatial topological index for the 3D point cloud model of the tunnel face in absolute coordinate system, and initialize the iteration points. ,make , This represents the current iteration number; ② Using the constructed KD-tree spatial topological index, query the distance to the current iteration point in the 3D point cloud model of the tunnel face. Euclidean distance nearest K Each set of 10 neighboring points constitutes a local neighborhood point set. ; ③ Extracted local neighborhood point set Local microplane equations are obtained by performing microplane fitting; ④ Calculate the spatial intersection point of the borehole trajectory line and the local microplane based on the reverse spatial linear equation and the local microplane equation. ; ⑤ Calculate spatial intersection points With the current iteration point Spatial Euclidean distance between Judgment: If Or reach the maximum number of iterations If the iteration converges, the final intersection point coordinates are determined. As the actual borehole coordinates on the tunnel face. Otherwise, Return to step ② and continue the next round of iterations until the convergence condition is met; where: To set an iteration error threshold; ⑥ Calculate the actual drilling depth based on the actual borehole opening coordinates and the designed absolute coordinates of the borehole bottom. .

[0011] Optionally, for the extracted local neighborhood point set The local microplane equation is obtained by performing microplane fitting, specifically including: Calculate the centroid coordinates of the local neighborhood point set. ; Construct the 3×3 covariance matrix of the local neighborhood point set H ; For covariance matrixH Perform eigenvalue decomposition to obtain three eigenvalues. , and and its corresponding eigenvectors; The eigenvector corresponding to the smallest eigenvalue is selected as the normal vector of the local microplane, and a coordinate system passing through the centroid is constructed. And the normal vector is The equations for the local microplane are expressed as follows: ; in: Let the coordinates of any point on the local microplane be... .

[0012] Optionally, the centroid coordinates of the local neighborhood point set The specific calculation formula is as follows: ; in: j Number the neighboring points; For the first j The coordinates of the neighboring points and All are represented as three-dimensional column vectors; covariance matrix H The specific calculation formula is as follows: .

[0013] Optionally, the spatial intersection point of the borehole trajectory line and the local microplane is calculated based on the reverse spatial linear equation and the local microplane equation. Specifically, it includes: Substituting the equation of the straight line in the reverse space of the borehole into the equation of the local microplane, the borehole depth parameter at the intersection of the straight line and the microplane is obtained. The specific formula is as follows: ; Will Substituting the equation of the reverse spatial line of the borehole back into the equation, we obtain the spatial intersection point. The specific formula is as follows: .

[0014] Optionally, the specific formula for calculating the actual drilling depth is as follows: .

[0015] In addition, the present invention also provides a readable storage medium storing computer program instructions, which, when executed by a processor, implement the borehole placement optimization method based on the point cloud constraint of the face as described above.

[0016] Additionally, an electronic device includes: at least one processor, at least one memory, and computer program instructions stored in the memory, wherein the computer program instructions are executed by the processor to perform the borehole placement optimization method based on the face point cloud constraint as described above.

[0017] This invention introduces three-dimensional point cloud data from lidar to simply project the ideal design coordinates onto the working face, ensuring that the bottom of the borehole is coplanar for blasting effect. It also calculates the actual borehole coordinates and actual drilling depth to adapt to uneven rock surfaces, greatly improving blasting quality. This ensures that the bottom of all boreholes is located on the same theoretical design plane after blasting, solving the problems of uneven blasting foundations and serious over- or under-excavation caused by uneven working faces. It avoids the waste of explosives or insufficient blasting energy caused by a one-size-fits-all drilling depth in traditional construction, saving construction costs and improving operational safety. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram illustrating the process of calculating the actual borehole coordinates and the actual drilling depth in an embodiment of the present invention. Figure 2 This is a schematic diagram illustrating the calculation process for obtaining the actual orifice coordinates in an embodiment of the present invention.

[0020] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0022] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0023] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0024] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0025] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0026] This invention proposes a method, medium, and equipment for optimizing borehole placement based on point cloud constraints at the working face, aiming to solve the problem that existing methods cannot accurately place the designed boreholes on the actual working face.

[0027] This embodiment provides a borehole placement optimization method based on point cloud constraints at the working face, including the following steps: The tunnel face was scanned using a 3D lidar to obtain unmeshed point cloud data of the face in a local coordinate system. The point cloud model of the face was then transformed into the absolute coordinate system of the tunnel construction using a coordinate registration algorithm, resulting in a 3D point cloud model of the face in absolute coordinates. In this embodiment, a 3D LiDAR scanner is used to scan the tunnel face to obtain high-precision point cloud data (the distance between points must be less than 1 cm). Using a coordinate registration algorithm (such as the ICP algorithm, based on the design borehole measurements using a total station), the point cloud data is transformed from the scanner's local coordinate system to the absolute coordinate system of the tunnel construction, resulting in a 3D point cloud model of the tunnel face in absolute coordinates. .

[0028] Based on the tunnel construction coordinate system established according to the known tunnel construction process, this coordinate system uses the tunnel entrance axis as the X-axis, a direction perpendicular to the ground as the Z-axis, and a direction perpendicular to both the X and Z axes as the Y-axis. The azimuth angle of the positive X-axis is then determined. α 0 and tilt angle β 0.

[0029] The reverse spatial linear equation of the blast hole, constructed based on the coplanar constraint of the hole bottom in the tunnel blasting design method, specifically includes: Obtaining the first from the tunnel blasting design scheme The absolute coordinates of the design boreholes. Design hole depth Horizontal angle and longitudinal angle ; Calculate the first based on the absolute coordinates of the designed orifice. The design of the absolute coordinates of the bottom of each borehole And according to the horizontal angle and longitudinal angle Define the direction vector of the borehole centerline. ; In this embodiment, to ensure that the bottom of all boreholes lies on the same plane (i.e., the designed blasting profile surface), it is necessary to calculate the first... The absolute coordinates of the bottom of the design borehole, the first... The design of the absolute coordinates of the bottom of each borehole The calculation formula is as follows: ; Specifically: when the centerline of the blast hole is located to the left of the tunnel excavation direction. A positive value occurs when the centerline of the blast hole is located to the right of the tunnel excavation direction. Negative values; longitudinal angle The value is positive when it is an elevation angle and negative when it is a depression angle; Direction vector of borehole centerline The specific expression is as follows: .

[0030] Starting from the absolute coordinates of the bottom of the borehole, extend along the borehole axis towards the borehole opening to construct the reverse spatial straight line equation of the borehole, as shown in the following expression: ; in: For the first The absolute coordinates of the bottom of each borehole are designed. This represents the actual spatial distance from a point on the trajectory line to the bottom of the hole, i.e., the potential actual drilling depth. .

[0031] In this embodiment, considering the discrete distribution of point clouds, it is often difficult for a three-dimensional straight line to precisely pass through a specific point cloud data point. Therefore, a method combining spatial iterative search and local microplane fitting is used to accurately solve for the intersection point of the straight line and the uneven rock surface. Specifically, based on the three-dimensional point cloud model of the working face and the three-dimensional spatial trajectory equation of the borehole, the actual borehole coordinates and actual borehole depth are calculated using a method combining spatial iterative search and local microplane fitting. This includes: ① Construct a KD-tree spatial topological index for the 3D point cloud model of the tunnel face in absolute coordinate system, and initialize the iteration points. ,make ; This represents the current iteration number; ② Using the constructed KD-tree spatial topological index, query the distance to the current iteration point in the 3D point cloud model of the tunnel face. Euclidean distance nearest K Each set of 10 neighboring points constitutes a local neighborhood point set. In this embodiment, K The value is usually chosen between 10 and 50.

[0032] ③ Extracted local neighborhood point set The local microplane equation is obtained by performing microplane fitting, specifically including: Calculate the centroid coordinates of the local neighborhood point set. Centroid coordinates of a local neighborhood point set The specific calculation formula is as follows: ; in: j Number the neighboring points; For the first j The coordinates of the neighboring points and All are represented as three-dimensional column vectors; Construct the 3×3 covariance matrix of the local neighborhood point set H The specific calculation formula is as follows: ; in: This is a transpose.

[0033] For covariance matrix H Perform eigenvalue decomposition to obtain three eigenvalues. , and and its corresponding eigenvectors; The eigenvector corresponding to the smallest eigenvalue is selected as the normal vector of the local microplane, and a coordinate system passing through the centroid is constructed. And the normal vector is The equations for the local microplane are expressed as follows: ; in: P Let the coordinates of any point on the local microplane be... This point is also a point on the straight line in the reverse space of the borehole, and is the intersection of the plane and the line. The formula means that it is derived from the centroid coordinates. Point to any point on the plane P vector Must be the normal vector of the plane Perpendicular (i.e., the dot product is zero), any point that satisfies this condition. P They are all on this plane.

[0034] ④ Calculate the spatial intersection point of the borehole trajectory line and the local microplane based on the reverse spatial linear equation and the local microplane equation. Specifically, it includes: because P The point is also a point on the straight line in the reverse space of the borehole, therefore it also satisfies the equation of the straight line in the reverse space of the borehole; substituting the equation of the straight line in the reverse space of the borehole into the equation of the local microplane, the drilling depth parameter of the intersection point of the straight line and the microplane is obtained. , Determine the drilling depth parameters at the intersection of the straight line and the microplane. : ; The updated borehole depth parameters are obtained. for: ; Will Substituting the equation of the reverse spatial line of the borehole back into the equation, we obtain the spatial intersection point. The specific formula is as follows: .

[0035] ⑤ Calculate spatial intersection points With the current iteration point Spatial Euclidean distance between Judgment: If Or reach the maximum number of iterations If the iteration converges, the final intersection point coordinates are determined. As the actual borehole coordinates on the tunnel face. Otherwise, Return to step ② and continue the next round of iterations until the convergence condition is met; where: To set the iteration error threshold, this embodiment uses 1 cm; In this embodiment, spatial Euclidean distance The formula is: ; ⑥ Calculate the actual drilling depth based on the actual borehole opening coordinates and the designed absolute coordinates of the borehole bottom. .

[0036] The specific formula for calculating the actual borehole depth is as follows: .

[0037] In this embodiment, if This indicates that there is a protrusion on the working face at that location; if This indicates that there is a depression on the working face at that location.

[0038] In addition, the actual borehole depth was calculated. Following this, it also includes: outputting optimized placement data, specifically, the actual coordinates of all boreholes. and the corresponding actual drilling depth The data is sent to the rock drilling rig control system or the mobile terminal of the on-site construction personnel to guide precise three-dimensional spatial hole alignment and depth drilling.

[0039] This embodiment also provides a readable storage medium storing computer program instructions, which, when executed by a processor, implement the borehole placement optimization method based on the point cloud constraint of the face as described above.

[0040] It should be noted that the device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Furthermore, in the accompanying drawings of the device embodiments provided by this invention, the connection relationships between modules indicate that they have communication connections, which can be specifically implemented as one or more communication buses or signal lines. Those skilled in the art can understand and implement this without any creative effort.

[0041] This embodiment also includes an electronic device, comprising: at least one processor, at least one memory, and computer program instructions stored in the memory, wherein the computer program instructions are executed by the processor to perform the mining slope stability analysis method as described above.

[0042] For example, the computer program may be divided into one or more modules / units, which are stored in the memory and executed by the processor to complete the present invention. The one or more modules / units may be a series of computer program instruction segments capable of performing a specific function, which describe the execution process of the computer program in the electronic device.

[0043] The electronic device can be a mobile phone, desktop computer, laptop, handheld computer, cloud server, or other computing device. The electronic device may include, but is not limited to, processors and memory. For example, the electronic device may also include input / output devices, network access devices, buses, etc.

[0044] The processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor or any conventional processor. The processor is the control center of the electronic device, connecting all parts of the electronic device via various interfaces and lines.

[0045] The memory can be used to store the computer program and / or modules. The processor implements the computer program by running or executing the computer program and / or modules stored in the memory, and by calling data stored in the memory. The memory may mainly include a program storage area and a data storage area. The program storage area may store the operating system, at least one application program required for a function (such as sound playback function, image playback function, etc.), etc.; the data storage area may store data created according to the use of the mobile phone (such as audio data, phonebook, etc.). In addition, the memory may include high-speed random access memory, and may also include non-volatile memory, such as hard disk, memory, plug-in hard disk, smart media card (SMC), secure digital card (SD) card, flash card, at least one disk storage device, flash memory device, or other volatile solid-state storage device.

[0046] Wherein, if the modules / units integrated in the electronic device are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments of the present invention can also be implemented by a computer program instructing related hardware. The computer program can be stored in a readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include: any entity or device capable of carrying the computer program code, recording media, USB flash drives, portable hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc.

[0047] The above description is only a preferred embodiment of the present invention and does not limit the scope of the present invention. All equivalent structural transformations made under the inventive concept of the present invention using the contents of the present invention specification and drawings, or direct / indirect applications in other related technical fields, are included within the protection scope of the present invention.

Claims

1. A method for optimizing borehole placement based on point cloud constraints at the working face, characterized in that, Includes the following steps: The tunnel face was scanned using a 3D lidar to obtain unmeshed point cloud data of the face in a local coordinate system. The point cloud model of the face was then transformed into the absolute coordinate system of the tunnel construction using a coordinate registration algorithm, resulting in a 3D point cloud model of the face in absolute coordinates. Based on the tunnel blasting design method, the reverse spatial linear equation of the blast hole is constructed based on the coplanar constraint of the hole bottom; Based on the three-dimensional point cloud model of the working face and the three-dimensional spatial trajectory equation of the borehole, the actual borehole coordinates and actual borehole depth are calculated by combining spatial iterative search and local microplane fitting.

2. The borehole placement optimization method based on point cloud constraints at the working face as described in claim 1, characterized in that, The reverse spatial linear equation of the blast hole, constructed based on the coplanar constraint of the hole bottom in the tunnel blasting design method, specifically includes: Obtaining the first from the tunnel blasting design scheme The absolute coordinates of the design boreholes. Design hole depth Horizontal angle and longitudinal angle ; Calculate the first based on the absolute coordinates of the designed orifice. The design of the absolute coordinates of the bottom of each borehole And according to the horizontal angle and longitudinal angle Define the direction vector of the borehole centerline. ; Starting from the absolute coordinates of the bottom of the borehole, extend along the borehole axis towards the borehole opening to construct the reverse spatial straight line equation of the borehole, as shown in the following expression: ； in: For the first The absolute coordinates of the bottom of each borehole are designed. This represents the actual spatial distance from a point on the trajectory line to the bottom of the hole, i.e., the potential actual drilling depth. .

3. The borehole placement optimization method based on point cloud constraints at the working face as described in claim 2, characterized in that, No. The design of the absolute coordinates of the bottom of each borehole The calculation formula is as follows: ； Specifically: when the centerline of the blast hole is located to the left of the tunnel excavation direction. A positive value occurs when the centerline of the blast hole is located to the right of the tunnel excavation direction. Negative values; longitudinal angle The value is positive when it is an elevation angle and negative when it is a depression angle; Direction vector of borehole centerline The specific expression is as follows: 。 4. The borehole placement optimization method based on point cloud constraints at the working face as described in claim 3, characterized in that, Based on the 3D point cloud model of the drilling face and the 3D spatial trajectory equation of the borehole, a method combining spatial iterative search and local microplane fitting is used to calculate the true borehole coordinates and the actual borehole depth, specifically including: ① Construct a KD-tree spatial topological index for the 3D point cloud model of the tunnel face in absolute coordinate system, and initialize the iteration points. ,make , This represents the current iteration number; ② Using the constructed KD-tree spatial topological index, query the distance to the current iteration point in the 3D point cloud model of the tunnel face. Euclidean distance nearest K Each set of 10 neighboring points constitutes a local neighborhood point set. ; ③ Extracted local neighborhood point set Local microplane equations are obtained by performing microplane fitting; ④ Calculate the spatial intersection point of the borehole trajectory line and the local microplane based on the reverse spatial linear equation and the local microplane equation. ; ⑤ Calculate spatial intersection points With the current iteration point Spatial Euclidean distance between Judgment: If Or reach the maximum number of iterations If the iteration converges, the final intersection point coordinates are determined. As the actual borehole coordinates on the tunnel face. Otherwise, Return to step ② and continue the next round of iterations until the convergence condition is met; where: To set an iteration error threshold; ⑥ Calculate the actual drilling depth based on the actual borehole opening coordinates and the designed absolute coordinates of the borehole bottom. .

5. The borehole placement optimization method based on point cloud constraints at the working face as described in claim 4, characterized in that, For the extracted local neighborhood point set The local microplane equation is obtained by performing microplane fitting, specifically including: Calculate the centroid coordinates of the local neighborhood point set. ; Construct the 3×3 covariance matrix of the local neighborhood point set H ; For covariance matrix H Perform eigenvalue decomposition to obtain three eigenvalues. , and and its corresponding eigenvectors; The eigenvector corresponding to the smallest eigenvalue is selected as the normal vector of the local microplane, and a coordinate system passing through the centroid is constructed. And the normal vector is The equations for the local microplane are expressed as follows: ； in: Let the coordinates of any point on the local microplane be... .

6. The borehole placement optimization method based on point cloud constraints at the working face as described in claim 5, characterized in that, Centroid coordinates of a local neighborhood point set The specific calculation formula is as follows: ； in: j Number the neighboring points; For the first j The coordinates of the neighboring points and All are represented as three-dimensional column vectors; covariance matrix H The specific calculation formula is as follows: 。 7. The borehole placement optimization method based on point cloud constraints at the working face as described in claim 6, characterized in that, The spatial intersection of the borehole trajectory line and the local microplane is calculated based on the reverse spatial linear equation and the local microplane equation. Specifically, it includes: Substituting the equation of the straight line in the reverse space of the borehole into the equation of the local microplane, the borehole depth parameter at the intersection of the straight line and the microplane is obtained. The specific formula is as follows: ； Will Substituting the equation of the reverse spatial line of the borehole back into the equation, we obtain the spatial intersection point. The specific formula is as follows: 。 8. The borehole placement optimization method based on point cloud constraints at the working face as described in claim 7, characterized in that, The specific formula for calculating the actual borehole depth is as follows: 。 9. A readable storage medium, characterized in that, It stores computer program instructions, which, when executed by a processor, implement the borehole placement optimization method based on point cloud constraints at the face as described in any one of claims 1 to 8.

10. An electronic device, characterized in that, include: The method for optimizing borehole placement based on point cloud constraints at the face of the tunnel as described in any one of claims 1 to 8 is provided by the processor.

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