A tunnel anchor rod supporting drilling construction method and system based on laser radar

Abstract

The application relates to the technical field of tunnel construction, and discloses a tunnel anchor rod supporting drilling construction method and system based on a laser radar, which comprises data acquisition, tunnel unevenness quantitative evaluation, drilling construction parameter determination and drilling execution. The application integrates quantitative initial spraying leveling, normal self-adaptive drilling, dynamic compensation mechanism of curve surface spacing and footage. Specifically, initial three-dimensional point clouds are matched with a design model to quantize unevenness, so as to guide accurate leveling; a local normal vector is calculated in real time through covariance matrix decomposition to correct a drilling posture; a fast advancing algorithm is introduced to compensate for the hole arrangement spacing deviation caused by the concave-convex rock surface, and the drilling machine footage depth is dynamically corrected in combination with the normal deviation value. The application ensures that the support density of the anchor rod on the uneven wall surface is constant and the effective anchoring length meets the standard, and significantly improves the efficiency and unmanned level of the tunnel drilling and anchoring operation.

Description

Technical Field

[0001] This invention relates to the field of tunnel construction technology, and in particular to a method and system for drilling tunnel anchor bolt support based on lidar. Background Technology

[0002] In tunnel construction using the drill-and-blast method under complex geological conditions, the New Austrian Tunneling Method (NATM) is currently the most mainstream construction concept, its core being to fully utilize the self-bearing capacity of the surrounding rock. After the tunnel section is blasted and excavated, initial support work of "preliminary shotcrete leveling + anchor bolt drilling" must be carried out quickly to seal the surrounding rock and control its deformation. However, due to the characteristics of the drill-and-blast method itself, the development of rock mass joints and fissures, and the control of blasting parameters, the actual excavated profile of the tunnel after blasting is often extremely irregular, with serious over- and under-excavation phenomena commonly occurring. Even after the first initial shotcrete process, there will still be a large number of visible depressions or protrusions on the wall surface. The mechanical mechanism of anchor bolt support requires that the anchor bolts be driven as perpendicular to the rock surface as possible, and the support plate (pad) at the tail of the anchor bolt must be in close contact with the initial shotcrete surface to establish effective prestress and provide tangential resistance. When the actual working surface has a large number of irregular undulations, how to efficiently and accurately complete the flatness judgment while ensuring the safety of construction personnel, and how to make the drilling and anchoring machinery adapt to this non-ideal three-dimensional curved surface, is a technical bottleneck that urgently needs to be overcome in the current intelligent and unmanned construction of tunnels.

[0003] The following solutions exist in the existing technology: 1. The traditional manual-dominated "human-machine collaboration" model involves the following steps: After blasting and initial shotcreting, experienced technicians or construction workers stand on a platform and assess the smoothness of the initial shotcrete surface by visual inspection or using simple rulers and searchlights. Protruding areas are manually removed, while recessed areas are repaired by the shotcrete operator. After leveling, anchor bolt hole positions are marked on the rock surface with red paint, and then the operator controls a traditional hydraulic drilling rig or pneumatic drill to drill the holes according to the marks.

[0004] 2. CNC / Programmed Trolley Hole Layout Based on Design Drawings (First Generation Automation): In recent years, major equipment manufacturers have launched computer-guided trolleys with a certain degree of automation (such as drilling and anchoring machines modified from three-arm rock drilling trolleys). Technicians import the theoretical design cross-section of the tunnel (CAD model) into the trolley's industrial control computer. The trolley's robotic arm automatically runs along a pre-set fixed grid (such as 1.2m × 1.2m spacing) and a fixed radial angle, performing "blind drilling."

[0005] 3. Preliminary perception system equipped with lidar (current latest technology): Some advanced tunnel construction equipment has begun to introduce lidar (LiDAR) or 3D vision sensors. There are two main application scenarios: one is for automatic positioning and navigation of the trolley; the other is for "over-excavation and under-excavation scanning" after blasting and before shotcreting to generate volume reports to guide the later settlement or adjustment of blasting parameters.

[0006] Based on the above, it is clear that existing equipment either relies on high-risk manual intervention or falls into "mechanized blind drilling" that is detached from the actual terrain. When faced with the inevitable unevenness of the tunnel's initial sprayed wall surface, existing drilling and anchoring equipment cannot autonomously determine where leveling is needed or how effective the leveling will be. Furthermore, it cannot automatically calculate and deploy anchor spacing and local spatial angles based on the actual three-dimensional geological model after leveling. Therefore, it is necessary to provide a new construction method to solve the above-mentioned technical problems. Summary of the Invention

[0007] The main objective of this invention is to provide a drilling method for tunnel anchor bolt support based on lidar, solving the problems of existing technologies that rely on manual intervention or cannot automatically calculate and set anchor bolt spacing and local spatial angles. The specific technical solution is as follows: A method for drilling tunnel anchor bolt support based on lidar includes the following steps: Step 1, data acquisition, specifically includes: using the lidar installed on the equipment to perform a fan-shaped scan of the tunnel initial spraying working face to obtain raw point cloud data; Step 2, quantitative evaluation of tunnel unevenness, specifically: constructing an initial 3D model of the tunnel; registering the initial 3D model of the tunnel with a pre-stored tunnel design cross-section model in the coordinate system and calculating the deviation; quantitatively evaluating the tunnel unevenness based on the deviation, dividing the area into normal area, area to be filled, and area to be removed; filling the area to be filled; and removing the area to be removed. Step 3: Use the lidar installed on the equipment to perform a fan-shaped scan of the tunnel's initial shotcrete working face to obtain the leveled 3D mesh point cloud data; compare the leveled 3D mesh point cloud data with the data in the pre-stored tunnel design cross-section model to obtain the advance compensation amount. ; Step 4: Determining the drilling parameters for tunnel anchor bolt support, specifically including: The determination of the drilling parameters for the anchor bolting machine involves the following steps: Generating and mapping a three-dimensional reference hole position based on two-dimensional design parameters. Specifically, this involves: reconstructing the two-dimensional design parameters into a theoretical three-dimensional surface; dividing the theoretical hole position into a mesh based on the design parameters to obtain the theoretical three-dimensional hole position; projecting the theoretical three-dimensional hole position onto the leveled three-dimensional mesh point cloud data obtained in step three to obtain the actual hole position; extracting the local normal vector of the actual hole position; and calculating the initial yaw and pitch angles of the anchor bolting machine drilling based on the actual hole position and the local normal vector. The determination of drilling angle, drilling position coordinates, and drilling depth is specifically as follows: based on the local normal vector derivation of the PCA algorithm, the normal vector of the local micro-plane of the rock surface is obtained to obtain the drilling angle; based on the geodesic compensation of surface integral, the anchor bolt drilling position coordinates are obtained; based on the dynamic compensation of effective anchorage length, the drilling depth is obtained. Step 5: Drilling is carried out based on the drilling parameters for tunnel anchor support obtained in Step 4.

[0008] Preferably, the strategy for dividing the normal area, the area to be filled, and the area to be removed in step two is as follows: If the deviation is greater than the first set threshold, it is determined to be an area to be filled; If the deviation is less than the second set threshold, it is determined to be an area to be removed; If the deviation is between the second set threshold and the first set threshold, it is determined to be in the normal range.

[0009] In this embodiment, the first set threshold is: The second threshold is set as In this embodiment, a small-scale shotcrete and removal tool (see prior art) is used to achieve precise filling of the area to be filled and complete removal of the area to be removed.

[0010] Preferably, step four, which parametrically reconstructs the two-dimensional design into a theoretical three-dimensional surface, specifically includes: Establish a global coordinate system for tunnel construction ,in: The axis runs along the tunnel's design centerline, i.e., the longitudinal advance direction; The axis is horizontal; The axis is in the vertical direction; Two-dimensional contour line extraction: Read the standard cross-sectional contour parameters of the corresponding mileage section from the design drawings. The standard cross-sectional contour parameters include the center coordinates of each arc segment. and radius ;Parameterize the 2D contour with respect to arc length curve equation ; 3D surface stretching: stretching the 2D contour along... A stretching scan is performed along the axial direction to construct the theoretical three-dimensional design surface equation for the tunnel. .

[0011] Preferably, step four, the theoretical hole location meshing based on design parameters, specifically includes: Extract anchor bolt arrangement parameters from the design drawings, including circumferential spacing. Longitudinal spacing and the layout; Taking the common quincunx pattern (staggered arrangement) as an example, the theoretical coordinate parameters on the curved surface are calculated using the following formula. : Vertical axis : ; Circular arc length coordinates : ;

[0012] in: This refers to the circumferential sequence number of the anchor bolt, in column units; This refers to the longitudinal sequence number of the anchor bolt, in rows. Theoretical coordinate parameters Substituting the theoretical tunnel three-dimensional design surface equation In the process, the initial three-dimensional spatial coordinates of all anchor bolt hole locations on the theoretically designed curved surface are calculated. as follows: When j is an odd number: ; When j is an even number: ; Simultaneously, the three-dimensional design surface equations of the tunnel were... The derivative is obtained, and the absolute design coordinates of the borehole location in three-dimensional space are then used. Substituting the values ​​into the equation and differentiating, we obtain the standard drilling direction for that point on the theoretical surface, i.e., the theoretical normal vector. ; Obtain the theoretical three-dimensional hole positions.

[0013] Preferably, in step four, the theoretical three-dimensional hole position is ray-projected onto the leveled three-dimensional mesh point cloud data obtained in step three. Based on theoretical anchor hole position Starting from the theoretical drilling direction Constructing space ray equations , where: t>0, t is the distance scalar the ray travels along the direction vector; The leveled 3D mesh point cloud data includes a set of spatial triangular facets. (where n is the total number of facets); take any one of the triangular facets. The coordinates of its three vertices are respectively Where: s = 1, 2, ..., n; The following formula is used to calculate the triangular facet. normal vector : ; ray equation Substitute into the plane equation In the solution, the distance scalar is obtained. for: ; Where: P is any point in the triangular plane; denominator If the denominator This indicates that the ray is parallel to the plane and has no intersection point, so the facet is discarded. The obtained distance scalar Substitution ray equation To obtain the actual anchor bolt hole position , i.e., ray equation Result: .

[0014] Determine the actual hole position Then, the local normal vector of that point needs to be extracted as a reference for subsequent adjustments to the verticality of the anchor bolt.

[0015] Preferably, in step four, the local normal vector of the point is extracted based on the actual hole location. The following formula is used for calculation: ; in: This represents finding the magnitude of a vector, i.e., its length.

[0016] Preferably, the drilling angle is obtained in step four as follows: Extracting actual anchor bolt hole positions Point cloud clusters within the neighborhood Find its center of mass. ; Establish the local covariance matrix based on the centroid: , where: superscript Represents the transpose of a vector; For matrix Perform algebraic solutions to obtain its eigenvalues, and extract the eigenvector corresponding to the smallest eigenvalue. , that is, the local normal vector of the region; Take feature vector As the axis vector of the drill pipe The drilling angle is as follows: ; in: For output to the drill arm axis, shaft and The included angle of the axis.

[0017] Preferably, in step four, the coordinates of the next actual anchor bolt drilling position are calculated based on the designed anchor bolt spacing and the obtained actual anchor bolt hole positions. The specific calculation method is as follows: Based on the current actual anchor bolt hole position As the origin A fast-progression algorithm from graph theory is used to perform wavefront expansion on the edges of triangular mesh patches. During the expansion process, the wavefront expansion occurs when the total path length accumulated along the mesh edges first equals the design spacing. At that time, the position of the grid vertex where the wavefront is located is the next actual anchor bolt hole position. The corrected coordinates; theoretically, the continuous analytical calculation formula for the true path length (i.e., geodesic distance) extending along the rough rock surface between the two points is as follows: ; in: For two actual hole positions and The distance between them along the geodesic lines on the irregular rock surface; It is the line integral expression for the arc length of the path along the surface in three-dimensional space, used to analytically calculate the real physical path that extends continuously; The anchor spacing is the design requirement.

[0018] Preferably, the drilling depth acquisition in step four is specifically as follows: The actual drilling depth of the drilling rig is calculated using the following formula. : ; in: The effective rock anchorage length required by the design is determined by the total length of the system anchor bolts. With fixed reserved length jointly determined, that is ; This refers to the total length of the system's anchor bolts; Allow sufficient length for fixing the anchor bolt tail to protrude beyond the support plate and nut; This is the advance compensation amount, which is the normal deviation between the actual rock surface and the designed profile surface.

[0019] The effect of applying the technical solution of this invention is: The present invention provides a method for drilling construction of tunnel anchor bolt support based on lidar, which includes data acquisition, quantitative evaluation of tunnel unevenness, determination of drilling construction parameters for tunnel anchor bolt support, and drilling construction based on the drilling construction parameters. It adopts a quantitative initial spraying leveling mechanism, which changes the past practice of relying on visual inspection and intuition for leveling, thus improving accuracy. Based on the local normal vector derivation of the PCA algorithm and the introduction of a fast advance algorithm from graph theory, it automatically compensates for the shortening or lengthening of the spacing caused by unevenness, thereby improving the accuracy of obtaining drilling angle, drilling position coordinates, and drilling depth.

[0020] The present invention also provides a tunnel anchor support drilling construction system based on lidar, including tunnel anchor support drilling equipment, lidar and controller; The lidar is installed on the drilling equipment for tunnel anchor bolt support. The tunnel anchor bolt support drilling equipment includes a traveling mechanism and a drill arm mounted on the traveling mechanism; The lidar, walking mechanism, and drill arm are all connected to the controller; The controller includes one or more processors and a storage device for storing one or more programs; when the program is executed by the processor, it implements the above-described method for drilling holes for tunnel anchor support based on lidar. Attached Figure Description

[0021] 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.

[0022] Figure 1 This is a schematic diagram of the drilling construction method for tunnel anchor bolt support based on lidar in Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the PCA normal vector in Embodiment 1 of the present invention; Figure 3 This is a schematic diagram of the anchor bolt design and layout in Embodiment 1 of the present invention; Figure 4 This is a schematic diagram of geodesic distance in Embodiment 1 of the present invention; Figure 5 This is a cross-sectional view of the anchor bolt advance compensation in Embodiment 1 of the present invention.

[0023] 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

[0024] 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.

[0025] Example 1: A method for drilling tunnel anchor bolt support based on lidar, see details. Figure 1 This includes the following steps: Step 1, Data Acquisition, specifically includes: using a lidar installed on the equipment (in this embodiment, a drilling, anchoring, and grouting integrated machine can be used) to perform a fan-shaped scan of the tunnel's initial shotcrete working face to acquire raw point cloud data. ; Step 2: Quantitative evaluation of tunnel unevenness. Specifically, this involves: constructing an initial 3D model of the tunnel, preferably using a triangular meshing algorithm (such as Poisson reconstruction) to create a continuous 3D model of the initial sprayed surface; registering the initial 3D model of the tunnel with a pre-stored tunnel design cross-section model in coordinate systems and calculating the deviation; quantifying the tunnel unevenness based on the deviation, dividing the area into normal areas, areas to be filled, and areas to be removed; filling the areas to be filled; and removing the areas to be removed. Step 3: Use the lidar installed on the equipment to perform a fan-shaped scan of the tunnel's initial shotcrete working face to obtain the leveled 3D mesh point cloud data, ensuring that it accurately reflects the current geometric shape of the support face; compare the leveled 3D mesh point cloud data with the data in the pre-stored tunnel design cross-section model to obtain the advance compensation amount. ; Step 4: Determining the drilling parameters for tunnel anchor bolt support, specifically including: The determination of the drilling parameters for the anchor bolting machine involves the following steps: Generating and mapping a three-dimensional reference hole position based on two-dimensional design parameters. Specifically, this involves: reconstructing the two-dimensional design parameters into a theoretical three-dimensional surface; dividing the theoretical hole position into a mesh based on the design parameters to obtain the theoretical three-dimensional hole position; projecting the theoretical three-dimensional hole position onto the leveled three-dimensional mesh point cloud data obtained in step three to obtain the actual hole position; extracting the local normal vector of the actual hole position; and calculating the initial yaw and pitch angles of the anchor bolting machine drilling based on the actual hole position and the local normal vector. The determination of drilling angle, drilling position coordinates, and drilling depth is specifically as follows: based on the local normal vector derivation of the PCA algorithm, the normal vector of the local micro-plane of the rock surface is obtained to get the drilling angle; based on the geodesic compensation of surface integral, the drilling position coordinates are obtained; and based on the dynamic compensation of effective anchorage length, the drilling depth is obtained. Step 5: Drilling is carried out based on the drilling parameters for tunnel anchor support obtained in Step 4.

[0026] In this embodiment, the preferred strategy for dividing the normal area, the area to be filled, and the area to be removed in step two is as follows: If the deviation is greater than the first set threshold, it is determined to be an area to be filled; If the deviation is less than the second set threshold, it is determined to be an area to be removed; If the deviation is between the second set threshold and the first set threshold, it is determined to be in the normal range.

[0027] In this preferred embodiment, step four, which parametrically reconstructs the two-dimensional design into a theoretical three-dimensional surface, specifically includes: Establish a global coordinate system for tunnel construction ,in: The axis runs along the tunnel's design centerline, i.e., the longitudinal advance direction; The axis is horizontal; The axis is in the vertical direction; Two-dimensional contour line extraction: Read the standard cross-sectional contour parameters of the corresponding mileage section from the design drawings, including the center coordinates of each arc segment. and radius ;Parameterize the 2D contour with respect to arc length curve equation ; 3D surface stretching: stretching the 2D profile along the tunnel longitudinal direction The axis is stretched and scanned to construct the theoretical three-dimensional design surface equation for the tunnel. .

[0028] In this preferred embodiment, step four, the theoretical aperture mesh division based on design parameters, specifically includes: Extract anchor bolt arrangement parameters from the design drawings, including circumferential spacing. Longitudinal spacing and the layout; The theoretical coordinate parameters on the surface are calculated using the following formula. , That is, the one mentioned above Arc length coordinates The coordinates are along the longitudinal direction of the tunnel excavation: Vertical axis : ; Circular arc length coordinates : ; in: This refers to the circumferential sequence number of the anchor bolt, in column units; This refers to the longitudinal sequence number of the anchor bolt, in rows. Theoretical coordinate parameters Substituting the theoretical tunnel three-dimensional design surface equation In the process, the initial three-dimensional spatial coordinates of all anchor bolt hole locations on the theoretically designed curved surface are calculated. , Derivation process: Assume the standard cross-section of the design is a standard semicircular arch with radius R and center at the origin (o,o) (calculated counterclockwise from the horizontal right side): Step 1: Convert the arc length scalar to a central angle. : According to the arc length formula s = R We can calculate the local central angle corresponding to the anchor rod: ; If the tunnel's camber initiation point is not at 0 degrees, but rather has an initial angle... Then the equation is .

[0029] Step 2: Using trigonometric functions, convert the polar coordinates to polar Cartesian coordinates (x, y). Substitute the angles obtained above into the parametric equations of the circle to obtain the coordinates on the three-dimensional surface. ; ; Combined with the aforementioned vertical coordinates The calculation formula determines the initial design coordinates of the borehole location in three-dimensional space. The complete expansion is actually: When j is an odd number: ; When j is an even number: .

[0030] Simultaneously, the three-dimensional design surface equations of the tunnel were... The derivative is obtained, and the absolute design coordinates of the borehole location in three-dimensional space are then used. Substituting the values ​​into the equation and differentiating, we obtain the standard drilling direction for that point on the theoretical surface, i.e., the theoretical normal vector. ; Obtain the theoretical three-dimensional hole positions.

[0031] In this preferred embodiment, the step four, which involves ray projection of the theoretical three-dimensional hole location onto the leveled three-dimensional mesh point cloud data obtained in step three, specifically involves: Based on theoretical anchor hole position Starting from the theoretical drilling direction Constructing space ray equations , where: t>0, t is the distance scalar the ray travels along the direction vector; The leveled 3D mesh point cloud data includes a set of spatial triangular facets. (where n is the total number of facets); take any one of the triangular facets. (s=1, 2, ..., n), whose three vertex coordinates are respectively ; The following formula is used to calculate the triangular facet. normal vector

[0032] ; ray equation Substitute into the plane equation In the solution, the intersection distance scalar is obtained. for: ; Where: P is any point in the triangular plane; denominator If the denominator This indicates that the ray is parallel to the plane and has no intersection point, so the surface is discarded.

[0033] The obtained distance scalar Substitution ray equation To obtain the actual anchor bolt hole position , i.e., ray equation Result: .

[0034] PCA normal vector diagram as follows Figure 2 As shown.

[0035] In this preferred embodiment, step four involves extracting the local normal vector of the point based on the actual hole location. The following formula is used for calculation: ; in: This represents finding the magnitude of a vector, i.e., its length.

[0036] In this embodiment, based on the calculated actual hole position and local normal vector By combining the forward and inverse kinematic equations of the combined trolley robotic arm, the initial yaw and pitch angles of the anchor bolt drilling machine are calculated, completing the mapping transformation from theoretical anchor bolt placement to actual anchor bolt placement. The schematic diagram of the anchor bolt design and placement in this embodiment is shown below. Figure 3 As shown.

[0037] In this preferred embodiment, the drilling angle is obtained in step four as follows: Extract the actual orifice Point cloud clusters within the neighborhood Find its center of mass. ; Establish the local covariance matrix based on the centroid: , where: superscript Represents the transpose of a vector; For matrix Perform algebraic solutions to obtain its eigenvalues, and extract the eigenvector corresponding to the smallest eigenvalue. , that is, the local normal vector of the region; Take feature vector As the axis vector of the drill pipe The drilling angle is as follows: ; in: This is the angle between the coordinate axes output to the drill arm.

[0038] In this preferred embodiment, step four involves calculating the coordinates of the next actual anchor bolt drilling position based on the designed anchor bolt spacing and the already obtained actual anchor bolt hole positions. The specific calculation method is as follows: The current actual anchor bolt hole position obtained in the aforementioned steps As the origin A fast-progression algorithm from graph theory is used to perform wavefront expansion on the edges of triangular mesh patches. During the expansion process, the wavefront expansion occurs when the total path length accumulated along the mesh edges first equals the design spacing. At that time, the position of the grid vertex where the wavefront is located is the next actual anchor bolt hole position. The corrected coordinates. Theoretically, the continuous analytical calculation formula for the true path length (i.e., geodesic distance) extending along the rough rock surface between the two points is as follows: .

[0039] The above formula establishes the quantitative relationship between the actual surface path and the designed spacing between adjacent holes.

[0040] In the formula: For two actual hole positions and The distance between them along the geodesic lines on the irregular rock surface; It is the line integral expression for the arc length of the path along the surface in three-dimensional space, used to analytically calculate the real physical path that extends continuously; This represents the required anchor bolt spacing as per design specifications. All terms in the formula are in units of length, with meters as the unit.

[0041] A diagram of geodesic distance is shown below. Figure 4 As shown.

[0042] Its specific calculation theory is based on actual three-dimensional discrete triangular patches. The above continuous integration process solves the equations using a fast-progression algorithm. The core meaning of this equation is that the spatial rate of change of the scalar field T along its gradient direction (the direction of the fastest change) is always equal to 1, where the scalar field T represents physical quantities such as the shortest distance to the target boundary and the potential field that have only magnitude but no direction. This represents the gradient of the scalar field T. This indicates finding the magnitude of a vector, i.e., its length.

[0043] The algorithm is based on Given a source point, calculate the shortest discrete cumulative distance T from each vertex on the grid to the source point. When the wavefront extends to a vertex, and the cumulative distance T to that vertex first satisfies... At that time, the vertex is extracted as .

[0044] In this preferred embodiment, the drilling depth acquisition in step five specifically involves: The actual drilling depth of the drilling rig is calculated using the following formula. : ; in: The effective rock anchorage length required by the design is determined by the total length of the system anchor bolts. With fixed reserved length jointly determined, that is The unit is meters; This represents the total length of the system's anchor bolts, in meters. The length of the anchor bolt tail that needs to be exposed outside the support plate and nut for fixing is specified in meters. The advance compensation is the normal deviation between the actual rock surface and the designed profile surface. Its value is equal to the length of the distance scalar t obtained by intersecting the ray along the direction vector in the previous steps, and the unit is meters.

[0045] The cross-sectional view of the anchor bolt advance compensation in this embodiment is as follows: Figure 5 As shown.

[0046] In this embodiment, dynamic compensation for effective anchoring length is adopted, which can eliminate the problem of insufficient or excessive rock penetration depth of anchor bolts caused by over- or under-excavation of the initial sprayed surface.

[0047] Applying the solution of this embodiment, the actual anchor bolt hole position With local normal vector Specifically, the acquisition is as follows: 1. Local environmental feature extraction Initial Input: The system determines the approximate location of the next borehole position based on the geodesic algorithm. Data Retrieval: A radius is defined centered on this approximate location. A cylindrical search space, from the global grid Extract the point cloud subset within the region. (A total of 1240 discrete points) and their corresponding 2100 triangular patches.

[0048] 2. Actual hole position coordinates Refined determination Algorithm execution: An intersection algorithm using rays and a set of local triangle faces is employed. Measured data: Coordinates of the theoretical mapping point (design surface): Rays and mesh patches The intersection point (i.e., the actual hole position) The coordinates are calculated as follows: Physical meaning: This data accurately reflects the slight lateral shift of the borehole location caused by the local undulations of the rock surface at this location.

[0049] 3. Local normal vector Solution for (i.e., drilling attitude): In order for the anchor plate to fit flat against the rock surface, the drilling direction must be as perpendicular as possible to the local rock surface.

[0050] Step A (Centroid Decentration): Calculate the point cloud center of mass ; Step B (Covariance Matrix Analysis): Using the PCA algorithm, calculate the eigenvector corresponding to the minimum eigenvalue of the local point cloud distribution. Calculation result: Theoretical design normal vector. The actual normal vector after local fitting. .

[0051] Offset angle calculation: the angle between the actual borehole axis and the theoretical design axis. The calculation is as follows: ; Since both are unit direction vectors with magnitudes approaching 1, substituting the coordinate values ​​yields: ; ; There is a difference between the actual borehole axis and the theoretical design axis. The attitude correction angle.

[0052] The specific technical effects of using the above methods are as follows: ① Eliminate installation stress: If according to the theoretical normal vector During drilling, due to the local tilt of the rock surface, after the anchor bolt is installed, the support plate will have a local gap with the rock surface, resulting in uneven stress or even deformation of the support plate.

[0053] ② Achieve precise alignment: The output of this embodiment The attitude command enabled the rock drill's power head to perform fine-tuning of its attitude before contacting the rock surface, ensuring that the perpendicularity error between the borehole axis and the local rock surface was less than [a certain value]. This greatly improves the overall stability of the support structure.

[0054] Based on geodesic distance The adaptive optimization of adjacent hole positions and spacing verification are as follows: This embodiment aims to verify how the present invention can ensure the uniformity of anchor support density through geodesic algorithm in the case of extremely irregular rock surfaces (with deep grooves or local protrusions).

[0055] 1. Scene setting and design input: Construction location: Section K15+230 of the tunnel, right side of the arching line.

[0056] Rock surface characteristics: Due to well-developed geological joints in this area, the blasting created a rock surface with a maximum depth of [missing information]. Irregular pits. Design spacing constraints: Design specifications require circumferential spacing of anchor bolts. .

[0057] 2. Algorithm execution process (data flow): Starting point determined: The system has completed the first... Anchor bolt hole position The actual coordinate mapping.

[0058] Geodesic wavefront spreading: As the wave source, in the reconstructed triangular mesh patch set The Fast Path Model (FMM) algorithm is initiated. Optimization criteria: The algorithm performs discrete distance accumulation on the undulating triangular mesh boundary to approximate the continuous calculus of the real surface path. When the cumulative geodesic distance Accurately achieve At that moment, the system captures the grid vertex and defines it as the actual hole position of the next anchor bolt. .

[0059] 3. Comparison and verification data (core value manifestation): The system calculated synchronously. and The Euclidean straight-line distance (spatial straight-line distance) between them was calculated, and the aperture layout results for this area if the traditional projection method were used were extracted. The actual measured data for this scheme are: geodesic distance. The corresponding Euclidean straight-line distance Traditional projection method simulation data: If the traditional plane projection method is used, the actual surface distance (geodetic distance) between anchor bolts will reach approximately... .

[0060] 4. Technical Effects ① Prevent excessive spacing: In concave areas, if the anchors are arranged according to traditional planar projection, the actual distance between the anchors and the rock surface will become too large due to the "crossing mountains and valleys" ( This leads to weak areas in the support structure.

[0061] ② Achieving uniform support: This invention achieves uniform support through... Optimized hole position Although it appears closer on a straight line in space (only) However, because it extends close to the rock surface, it perfectly ensures that the mechanical spacing of the anchor bolts on the irregular surrounding rock surface is always equal to the specified distance. This achieves true full-section uniform support, effectively avoiding the risk of collapse caused by uneven local stress.

[0062] The calculation of anchor bolt single-hole advance compensation data based on point cloud deviation is as follows: To verify the adaptive hole layout and advance control capabilities of this invention under complex rock surfaces, an anchor bolt drilling operation was carried out in a local over-excavation area of ​​a tunnel (i.e., the actual rock surface is deeper than the design outline) as an example. The specific data flow and compensation calculation process is as follows: 1. System preset parameters (anchor bolt material properties): The system reads the design dimension requirements of the standard system anchor bolts for this section: Total length of anchor bolt : Fixed reserved length : (This data represents a rigid hardware constraint used for external support plate installation, washer and nut tightening.) Standard effective anchorage length: based on the formula... The target effective rock penetration depth, i.e., the effective anchoring length, is locked at this hole position. .

[0063] 2. Algorithm solution parameters (sensing and computation output) Based on the irregular point cloud mesh leveled by 3D laser scanning, the system performs ray intersection calculations from the theoretical design coordinates of the hole location along the normal vector to the actual mesh surface. The intersection distance scalar is obtained by solving the ray equation. Calculation yielded (A positive value indicates that the actual rock mass is outside the design outline, meaning there is over-excavation and depression). Excavation compensation amount. The system directly converts the intersection distance into compensation control parameters and outputs the advance compensation amount. .

[0064] 3. Terminal execution data (final trolley motion instructions) To ensure that the anchor bolt exists Even with over-drilling of the pit, the design-required anchoring depth is still met. The system issues a final advance command to the drilling rig after dynamic compensation: Total advance depth of the rock drill: .

[0065] The effect of applying the technical solution of this invention is: 1. Optimal Anchoring Stress State: Through a unique Local Normal Vector Algorithm (PCA), the drill rod is always driven perpendicular to the actual microscopic rock surface. This achieves maximum fit between the anchor plate and the irregular initial grouting surface, maximizing the prestress and shear resistance of the anchor rod.

[0066] 2. Uniform support grid density: A rapid advancement algorithm is introduced to correct the straight-line spacing in three-dimensional space to the "shortest crawling distance" along undulating surfaces. This ensures that the support density of the tunnel wall remains constant under any extreme terrain, effectively eliminating support blind spots.

[0067] 3. Precise effective rock penetration depth: Based on the normal deviation value calculated using 3D laser point cloud analysis (… This system dynamically compensates for the drilling depth of each hole, ensuring that the effective anchoring length of the anchor bolt reaches the target depth in the stable surrounding rock, regardless of how uneven the surface.

[0068] 4. Achieve intelligent drilling and anchoring operations: The algorithm directly generates kinematic control commands, effectively replacing manual drilling and posture adjustment based on experience, and greatly improving the efficiency and unmanned level of tunnel drilling and anchoring operations.

[0069] Example 2: This embodiment provides a tunnel anchor support drilling construction system based on lidar, including tunnel anchor support drilling equipment, lidar, and controller; The lidar is installed on the drilling equipment for tunnel anchor bolt support. The tunnel anchor bolt support drilling equipment includes a traveling mechanism and a drill arm mounted on the traveling mechanism; The lidar, walking mechanism, and drill arm are all connected to the controller; The controller includes one or more processors and a storage device for storing one or more programs; when the program is executed by the processor, it implements the above-described method for drilling holes for tunnel anchor support based on lidar.

[0070] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A method for drilling tunnel anchor bolt support based on lidar, characterized in that, Includes the following steps: Step 1, data acquisition, specifically includes: using the lidar installed on the tunnel anchor support drilling equipment to perform a fan-shaped scan of the tunnel initial shotcrete working face to obtain raw point cloud data; Step 2, quantitative evaluation of tunnel unevenness, specifically: constructing an initial 3D model of the tunnel; registering the initial 3D model of the tunnel with a pre-stored tunnel design cross-section model in the coordinate system and calculating the deviation; quantitatively evaluating the tunnel unevenness based on the deviation, dividing the area into normal area, area to be filled, and area to be removed; filling the area to be filled; and removing the area to be removed. Step 3: Use the lidar installed on the tunnel anchor support drilling equipment to perform a fan-shaped scan of the tunnel's initial shotcrete working face to obtain the leveled 3D mesh point cloud data; compare the leveled 3D mesh point cloud data with the data in the pre-stored tunnel design cross-section model to obtain the advance compensation amount. ; Step 4: Determining the drilling parameters for tunnel anchor bolt support, specifically including: The determination of drilling parameters for the anchor bolting machine specifically involves: generating and mapping a three-dimensional reference hole position based on two-dimensional design parameters, specifically: reconstructing the two-dimensional design parameters into a theoretical three-dimensional surface; and obtaining the theoretical three-dimensional hole position through theoretical hole position mesh generation based on the design parameters, specifically including: Extract anchor bolt arrangement parameters from the design drawings, including circumferential spacing. Longitudinal spacing and the layout; The theoretical coordinate parameters on the surface are calculated using the following formula. : Vertical axis : ; Circular arc length coordinates : ； in: This refers to the circumferential sequence number of the anchor bolt, in column units; This refers to the longitudinal sequence number of the anchor bolt, in rows; Theoretical coordinate parameters Substituting the theoretical tunnel three-dimensional design surface equation In the process, the initial three-dimensional spatial coordinates of all anchor bolt hole locations on the theoretically designed curved surface are calculated. as follows: When j is an odd number: ; When j is an even number: ; Simultaneously, the three-dimensional design surface equations of the tunnel were... The derivative is obtained, and the absolute design coordinates of the borehole location in three-dimensional space are then used. Substituting the values ​​into the equation and differentiating, we obtain the standard drilling direction of the borehole location on the theoretical surface, i.e., the theoretical normal vector. Obtain the theoretical three-dimensional hole positions; The theoretical three-dimensional hole position is projected onto the leveled three-dimensional mesh point cloud data obtained in step three to obtain the actual hole position; the local normal vector of the drilling position is extracted based on the actual hole position; the initial yaw angle and pitch angle of the anchor bolt machine drilling are calculated based on the actual hole position and the local normal vector. The determination of drilling angle, drilling position coordinates, and drilling depth is specifically as follows: based on the local normal vector derivation of the PCA algorithm, the normal vector of the local micro-plane of the rock surface is obtained to obtain the drilling angle; based on the geodesic compensation of surface integral, the anchor bolt drilling position coordinates are obtained; based on the dynamic compensation of effective anchorage length, the drilling depth is obtained. Step 5: Drilling is carried out based on the drilling parameters for tunnel anchor support obtained in Step 4.

2. The tunnel anchor bolt support drilling construction method based on lidar according to claim 1, characterized in that, The strategy for dividing the area into normal, unfilled, and unremoved regions in step two is as follows: If the deviation is greater than the first set threshold, it is determined to be an area to be filled; If the deviation is less than the second set threshold, it is determined to be an area to be removed; If the deviation is between the second set threshold and the first set threshold, it is determined to be in the normal range.

3. The drilling method for tunnel anchor bolt support based on lidar according to claim 1 or 2, characterized in that, Step four, which parametrically reconstructs the two-dimensional design into a theoretical three-dimensional surface, specifically includes: Establish a global coordinate system for tunnel construction ,in: The axis runs along the tunnel's design centerline, i.e., the longitudinal advance direction; The axis is horizontal; The axis is in the vertical direction; Two-dimensional contour line extraction: Read the standard cross-sectional contour parameters of the corresponding mileage section from the design drawings, including the center coordinates of each arc segment. and radius ;Parameterize the 2D contour with respect to arc length curve equation ; 3D surface stretching: stretching the 2D contour along... A stretching scan is performed along the axial direction to construct the theoretical three-dimensional design surface equation for the tunnel. .

4. The tunnel anchor bolt support drilling construction method based on lidar according to claim 1, characterized in that, Step four involves projecting the theoretical three-dimensional hole location onto the leveled three-dimensional mesh point cloud data obtained in step three. Specifically, this involves: Based on theoretical anchor hole position Starting from the theoretical drilling direction Constructing space ray equations , where: t>0, t is the distance scalar the ray travels along the direction vector; The leveled 3D mesh point cloud data includes a set of spatial triangular facets. Let n be the total number of facets; take any one of the triangular facets. The coordinates of its three vertices are respectively s = 1, 2, ..., n; The following formula is used to calculate the triangular facet. normal vector : ； ray equation Substitute into the plane equation In the solution, the distance scalar is obtained. for: ； Where: P is any point in the triangular plane; denominator ; The obtained distance scalar Substitution ray equation To obtain the actual anchor bolt hole position , i.e., ray equation Result: 。 5. The tunnel anchor bolt support drilling construction method based on lidar according to claim 4, characterized in that, In step four, the local normal vector of the point is extracted based on the actual hole location. The following formula is used for calculation: ； in: This represents finding the magnitude of a vector, i.e., its length.

6. The tunnel anchor bolt support drilling construction method based on lidar according to claim 1, characterized in that, The drilling angle is obtained in step four as follows: Extracting actual anchor bolt hole positions Point cloud clusters within the neighborhood Find its center of mass. ; Establish the local covariance matrix based on the centroid: , where: superscript Represents the transpose of a vector; For matrix Perform algebraic solutions to obtain its eigenvalues, and extract the eigenvector corresponding to the smallest eigenvalue. , that is, the local normal vector of the region; Take feature vector As the axis vector of the drill pipe The drilling angle is as follows: ； in: For output to the drill arm axis, shaft and The included angle of the axis.

7. The drilling method for tunnel anchor bolt support based on lidar according to claim 6, characterized in that, In step four, the coordinates of the next actual anchor bolt drilling position are calculated based on the designed anchor bolt spacing and the obtained actual anchor bolt hole positions. The specific calculation method is as follows: The current actual anchor bolt hole position obtained As the origin We employ a fast-progression algorithm from graph theory to perform wavefront expansion on the edges of triangular mesh faces. During the expansion process, the total path length accumulated along the grid edges first equals the design spacing. At that time, the position of the grid vertex where the wavefront is located is the next actual anchor bolt hole position. Corrected coordinates; Theoretically, the continuous analytical formula for calculating the true path length extending along a rough rock surface between two points is as follows: ； in: For two actual hole positions and The geodesic distance between them along the irregular rock surface; It is the line integral expression for the arc length of the path along the surface in three-dimensional space, used to analytically calculate the real physical path that extends continuously; The anchor spacing is the design requirement.

8. The tunnel anchor bolt support drilling construction method based on lidar according to claim 7, characterized in that, Step four, obtaining the drilling depth, specifically involves: The actual drilling depth of the drilling rig is calculated using the following formula. : ； in: The effective rock anchorage length required by the design is determined by the total length of the system anchor bolts. With fixed reserved length jointly determined, that is ; This refers to the total length of the system's anchor bolts; Allow sufficient length for fixing the tail of the anchor bolt to protrude beyond the support plate and nut; This is the advance compensation amount, which is the normal deviation between the actual rock surface and the designed profile surface.

9. A tunnel anchor bolt support drilling construction system based on lidar, characterized in that, This includes drilling equipment for tunnel anchor bolt support, lidar, and controllers; The lidar is installed on the drilling equipment for tunnel anchor bolt support. The tunnel anchor bolt support drilling equipment includes a traveling mechanism and a drill arm mounted on the traveling mechanism; The lidar, walking mechanism, and drill arm are all connected to the controller; The controller includes one or more processors and a storage device for storing one or more programs; when the program is executed by the processor, it implements the tunnel anchor bolt support drilling construction method based on any one of claims 1-8.

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