Double-assembly energy blasting profile overbreak measurement system based on point cloud registration

Abstract

The present application relates to the technical field of tunnel survey, and discloses a double-aggregation-energy blasting profile over-undercutting measurement system based on point cloud registration, which comprises a three-dimensional laser scanner, a common target and a computing device. The computing device pre-processes multi-station scanning point clouds, retains residual hole point sets and adjacent residual hole rock walls, establishes a post-blasting profile unit based on adjacent residual holes and inter-hole rock walls, obtains left hole mark point coordinates, right hole mark point coordinates, wall farthest point coordinates and design outer normal lines, compares double-hole string undulation ratios in overlapping areas of scanning stations, confirms the same name post-blasting profile unit, and obtains a station transformation matrix combined with the common target to form an engineering coordinate post-blasting rock wall point cloud. Then, cross sections are extracted along the design axis, and the measured profile is formed according to the inter-hole rock wall section to obtain cross section overcutting area, cross section undercutting area, measurement section overcutting volume and measurement section undercutting volume.

Description

Technical Field

[0001] This invention relates to the field of tunnel measurement technology, and more specifically, to a dual-energy blasting profile over-excavation and under-excavation calculation system based on point cloud registration. Background Technology

[0002] After tunnel drilling and blasting construction is completed, the outline quality usually needs to be verified through cross-sectional measurement results. A 3D laser scanner can acquire post-blast rock wall point clouds in a short time. Combined with a common target and engineering coordinate system, data from multiple scanning stations can be stitched together into a continuous post-blast rock wall point cloud. This cloud can then be compared with the design outline to obtain the over-excavation and under-excavation areas of the cross-section, as well as the over-excavation and under-excavation volumes of the measured section. This type of process has become a common data link in tunnel outline verification.

[0003] In dual-energy blasting scenarios, residual hole traces are usually left after the blasting of surrounding holes. The rock wall sections between adjacent residual holes directly reflect the local undulations of the post-blast profile. During on-site scanning, dust, operating equipment, arch frames, and the arrangement of measuring stations can affect the visibility of common targets. At the same time, the large-area rough surface of the tunnel rock wall presents similar undulations in the point cloud. When relying solely on common targets or the nearest point for measuring station stitching, the undulations of adjacent rock walls may be incorrectly matched, thus affecting the position of the subsequent cross-sectional profile.

[0004] Existing point cloud processing workflows typically filter and downsample rock wall points during the preprocessing stage to control the point cloud size and improve processing efficiency. Residual borehole identification workflows can also obtain residual borehole point sets through curvature, density, clustering, and circle or ellipse fitting. However, in over-excavation and under-excavation calculation tasks, borehole boundary points and points with significant deviations in the rock wall between boreholes are not ordinary noise points. If these points are deleted, diluted, or smoothed during preprocessing or contour fitting, the cross-sectional line may underestimate local bulging or shrinkage, leading to statistical discrepancies in the over-excavation and under-excavation areas.

[0005] When processing this type of data, engineering surveyors also need to consider two site constraints:

[0006] First, the registration of monitoring stations should make full use of the stable objects that can be observed on the rock wall itself after the blast, so as to reduce the impact of additional stations on the construction site.

[0007] Secondly, the formation of cross-sectional contours should not only pursue smooth curves, but should also retain local points that may affect area classification and volume statistics.

[0008] Therefore, a measurement system for tunnel rock walls after dual-energy blasting is needed. With the collaborative work of a 3D laser scanner, a common target, a design profile, and computing equipment, the residual borehole and the rock walls between boreholes are used for point cloud registration and profile measurement, and the results of over-excavation and under-excavation of the cross section and the measurement section are output. Summary of the Invention

[0009] This invention provides a dual-energy blasting profile over- and under-excavation calculation system based on point cloud registration, which solves the technical problems mentioned in the background art.

[0010] To achieve the above-mentioned objectives, the present invention provides the following technical solution.

[0011] The dual-energy blasting profile over- and under-excavation calculation system based on point cloud registration includes a three-dimensional laser scanner, a common target, and a calculation device for storing the design profile and target control coordinates. The calculation device is equipped with a point cloud preprocessing unit, a profile feature unit, a point cloud registration unit, and a cross-section measurement unit.

[0012] The point cloud preprocessing unit generates preprocessed scan point clouds, residual borehole point sets, ordinary rock wall point sets, and finely registered point sets from the original scan point cloud;

[0013] The contour feature unit is established by using adjacent residual holes and rock walls between holes to establish the post-blast contour unit, and obtains the coordinates of the left hole trace point, the right hole trace point, the coordinates of the farthest point on the wall and the design external normal. The undulation ratio of the double hole chord is a directed dimensionless feature quantity that characterizes the amount of undulation in the middle relative to the distance between the two holes.

[0014] The point cloud registration unit establishes a set of candidate post-blast contour units between scanning stations, compares the difference in undulation ratio in the double-hole chord and uniquely confirms the same post-blast contour unit, forms a three-point correspondence group from the same post-blast contour units, forms a common target station observation correspondence group and a common target control coordinate correspondence group from the common target station observation correspondence group, merges the three-point correspondence group and the common target station observation correspondence group to obtain the station transformation matrix and performs point cloud fine registration on the fine registration point set, and forms an engineering coordinate post-blast rock wall point cloud according to the common target control coordinate correspondence group;

[0015] The cross-section measurement unit projects the cross-section of the point cloud of the rock wall after the blasting of the engineering coordinates to construct the measured profile. It establishes a point-to-point correspondence between the design profile and the measured profile along the design outer normal and forms the over-excavation area and under-excavation area of ​​the cross section according to the profile deviation and the length of the profile segment.

[0016] The calculation equipment integrates the over-excavated area and under-excavated area of ​​the cross section according to the distance between adjacent cross sections to form the over-excavated volume and under-excavated volume of the measurement section.

[0017] Compared with the prior art, the present invention has the following substantial features and significant progress:

[0018] This invention utilizes existing adjacent residual holes and inter-hole rock walls after dual-energy blasting to establish post-blast contour units. Without altering the post-blast rock walls or adding blasting components, it incorporates the coordinates of the left and right hole trace points, the coordinates of the farthest point on the wall, and the designed external normal into the multi-station cloud registration and cross-sectional contour formation process. By using the undulation ratio of the two holes to assist in confirming the corresponding post-blast contour units, and jointly calculating the station transformation matrix with the observation of the common target, it can reduce the station correspondence deviation caused by similar rough rock walls. In the cross-section measurement, the residual hole point set and the coordinates of the farthest point on the wall are retained, which helps to reduce the situation where local undulations of the inter-hole rock walls are thinned or smoothed out, making the over-excavated area, under-excavated area, over-excavated volume, and under-excavated volume of the measurement section closer to the on-site scanning results of the post-blast rock walls. Attached Figure Description

[0019] Figure 1 This is a diagram of the system architecture and data processing mechanism for calculating the over- and under-excavation profile of dual-energy blasting based on point cloud registration, as described in this invention. Detailed Implementation

[0020] The following description is provided in conjunction with the accompanying drawings. It should be understood that the following embodiments are for illustrative purposes only and are not intended to limit the invention; those skilled in the art can make equivalent substitutions or combinations for the specific implementations.

[0021] This embodiment relates to a dual-energy blasting profile over-excavation and under-excavation calculation system based on point cloud registration, applicable to tunnel profile measurement scenarios after dual-energy blasting. In this scenario, adjacent residual holes and inter-hole rock walls have been formed on the post-blasting rock wall 100. The 3D laser scanner 200 can collect the original scan point cloud of the post-blasting rock wall 100 and the common target 300. The profile and target control coordinates 400 are designed as reference data for the computing device 500. The computing device 500 processes the original scan point cloud to generate the over-excavation and under-excavation calculation result 600.

[0022] like Figure 1 As shown, the computing device 500 includes a point cloud preprocessing unit 510, a contour feature unit 520, a point cloud registration unit 530, and a cross-section measurement unit 540. The point cloud preprocessing unit 510 receives the original scanned point cloud generated by the 3D laser scanner 200 and forms a preprocessed scanned point cloud, a set of residual borehole points, ordinary rock wall points, and a finely registered point set; the contour feature unit 520 establishes post-blast contour units based on adjacent residual boreholes and the rock walls between boreholes, and obtains the coordinates of the left borehole mark point, the coordinates of the right borehole mark point, the coordinates of the farthest point on the wall, the design external normal, and the undulation ratio of the chord of the two boreholes; the point cloud registration unit 530 completes the point cloud registration between scanning stations using the post-blast contour units and the common target 300; the cross-section measurement unit 540 forms the measured contour based on the post-blast rock wall point cloud in engineering coordinates, and outputs the over-excavated area of ​​the cross-section, the under-excavated area of ​​the cross-section, the over-excavated volume of the measurement section, and the under-excavated volume of the measurement section.

[0023] Specifically, the existing technology has the following problems: First, when the rock wall 100 after blasting presents a large area of ​​similar rough surface, it is necessary to improve the certainty of the correspondence between scanning stations; second, during the formation of the measured profile of the cross section, it is necessary to retain the local profile points between adjacent residual holes that affect the over-excavation area and under-excavation area of ​​the cross section; third, after the point cloud of the rock wall after blasting in the engineering coordinates is established to correspond with the design profile, it is necessary to form the over-excavation volume and under-excavation volume of the measurement section that can be directly used for engineering verification.

[0024] Furthermore, the implementation method of the point cloud preprocessing unit is as follows:

[0025] The point cloud preprocessing unit 510 is used to generate a preprocessed scan point cloud, a set of residual borehole points, ordinary rock wall points, and a finely registered point set from the original scan point cloud. The original scan point cloud is a set of points collected by the 3D laser scanner 200 at various scanning stations on the post-blast rock wall 100 and the common target 300, with each point corresponding to the spatial location of the visible surface on site. The preprocessed scan point cloud is a set of points after deleting outliers and performing voxel downsampling on the ordinary rock wall points, while still retaining the set of residual borehole points and the rock wall points between adjacent residual boreholes.

[0026] The point cloud preprocessing unit 510 first removes outliers from the original scanned point cloud through statistical filtering. The statistical filtering can adopt the neighborhood distance statistical method commonly used in point cloud processing: calculate the average distance of each point in the original scanned point cloud to its neighboring points, and remove points whose average distance deviates significantly from the overall distribution of the same scanning station as outliers.

[0027] Within the filtered original scanned point cloud, the point cloud preprocessing unit 510 calculates the local curvature and local point density of each point. The local curvature is uniquely determined by the eigenvalue of the neighborhood covariance matrix of the point, and the local point density is uniquely determined by dividing the number of points in the fixed-radius neighborhood by the volume of the fixed-radius neighborhood.

[0028] To ensure that the local curvature and local point density can be stably reproduced by the computing device 500, the point cloud preprocessing unit 510 first calculates the average point spacing in the filtered original scanned point cloud, and uses the average point spacing as a common metric for judging the local point density radius, statistical filtering, spatial clustering, and ellipse fitting residuals. The average point spacing is obtained by averaging the distances from each point to its nearest neighbor. When the point spacing distribution in a local area is significantly uneven, the point cloud preprocessing unit 510 calculates the average point spacing for each scanning station separately, without mixing points across scanning stations.

[0029] ;

[0030] in, This represents the average spacing between points in the point cloud, where N represents the number of points included in the statistics. This represents the distance from the a-th point to its nearest neighbor.

[0031] The calculation of local curvature is based on the coordinates of the q-th point, taking the coordinates of its neighboring points to form a neighborhood covariance matrix, and then denoteing the three eigenvalues ​​of the neighborhood covariance matrix in ascending order as follows: , and The local curvature of the q-th point is obtained by the following formula.

[0032] ;

[0033] in, Indicates the first Local curvature of a point coordinate, , and Let q represent the three eigenvalues ​​of the neighborhood covariance matrix of the q-th point. All eigenvalues ​​of the neighborhood covariance matrix are dimensionless (length squared), and the local curvature is dimensionless. If the sum of the three eigenvalues ​​is zero, the coordinates of the q-th point are not included in the determination of the curvature condition of the residual hole surface.

[0034] The fixed-radius neighborhood of the local point density is centered at the coordinates of the q-th point, and the radius of the local point density is taken as... The point cloud preprocessing unit 510 counts the number of neighboring points within the local point density radius, excluding the coordinates of the q-th point itself, and obtains the number of points using the following formula. Local point density of coordinates of a point.

[0035] ;

[0036] in, This represents the local point density of the q-th point. This represents the number of neighboring points within the local point density radius, excluding the coordinates of the q-th point itself. This represents the radius of the local point density. The dimension of the local point density is the negative cube of the length.

[0037] The number of neighborhood points for local curvature is set to 30; when the number of local points is less than 30, the maximum number of neighborhood points that can form a covariance matrix is ​​set to no less than 20. The curvature condition for residual hole surfaces is that the local curvature is higher than the 75th percentile of the local curvature of the original scanned point cloud after filtering at the same scanning station; the point density condition for residual hole surfaces is that the local point density is not lower than the 25th percentile of the local point density of the original scanned point cloud after filtering at the same scanning station.

[0038] During spatial clustering, the clustering distance threshold between candidate residual points is taken as follows: The number of points in the same cluster must be no less than 20; clusters with fewer than this number are not considered residual point sets. For ellipse fitting, the residual fitting condition is that the average fitting residual from the cluster to the fitted ellipse is no greater than [value missing]. Furthermore, the lengths of both the major and minor axes of the fitted ellipse are greater than 1. .

[0039] Candidate residual borehole points are those that simultaneously satisfy both the residual borehole surface curvature condition and the residual borehole surface point density condition. The residual borehole surface curvature condition characterizes the more pronounced surface change of the inner wall of the residual borehole or the edge of the borehole trace compared to ordinary rock wall points, while the residual borehole surface point density condition eliminates pseudo-curvature points caused by isolated noise. The point cloud preprocessing unit 510 performs spatial clustering on the candidate residual borehole points, ensuring that candidate residual borehole points on the same residual borehole trace are grouped into the same cluster point set.

[0040] For each cluster of points, the point cloud preprocessing unit 510 performs ellipse fitting, and the cluster of points whose fitting residuals satisfy the residual borehole fitting conditions are determined as the residual borehole point sets. Ellipse fitting is used to adapt to situations where residual boreholes exhibit approximately circular or elliptical contours under the influence of scanning viewpoint, cross-sectional projection, and rock wall inclination. The residual borehole fitting conditions for ellipse fitting can be jointly limited by the statistical range of the fitting residuals, the continuity of the clustered point sets, and the stability of the fitted contours. Its purpose is to identify residual borehole point sets that can serve as the boundaries of post-blast contour units.

[0041] The point cloud preprocessing unit 510 defines the residual borehole point set and the rock wall points between adjacent residual boreholes as the retention set, and defines the rock wall points outside the retention set as ordinary rock wall points. Voxel downsampling is only performed on ordinary rock wall points. This ensures that the source points of the residual borehole point set, the coordinates of the left borehole trace point, the coordinates of the right borehole trace point, and the coordinates of the farthest point on the wall are not deleted by voxel downsampling, while allowing ordinary rock wall points to reduce the amount of data through voxel downsampling.

[0042] The retained set is merged with the downsampled ordinary rock wall points to form a preprocessed scan point cloud. For ordinary rock wall points in the overlapping area of ​​adjacent scan stations, the point cloud preprocessing unit 510 determines them as a fine registration point set. The fine registration point set is used to provide the iterative objects of ordinary rock wall points for the point cloud registration unit 530 to perform fine registration of the point cloud.

[0043] The boundary processing method of the point cloud preprocessing unit 510 is as follows: if the residual borehole point set in a local area of ​​a certain scanning station is insufficient to meet the residual borehole fitting conditions due to occlusion, the residual borehole point set is not forcibly generated in that local area; if a certain ordinary rock wall point is identified as an outlier in statistical filtering, then the point will not enter the preprocessed scanning point cloud; if a point belongs to the residual borehole point set or the rock wall point between adjacent residual boreholes, then the point belongs to the retained set and will not be deleted due to voxel downsampling of ordinary rock wall points.

[0044] Furthermore, the implementation of the contour feature unit is as follows:

[0045] The contour feature unit 520 is used to establish a post-blast contour unit based on adjacent residual holes and the rock wall between holes, and to obtain the coordinates of the left hole trace point, the right hole trace point, the coordinates of the farthest point on the wall, the design outer normal, and the undulation ratio of the double hole chord. The post-blast contour unit is a measurement unit composed of two residual holes that are sequentially adjacent in the circumferential direction of the tunnel within the cross section and the rock wall points between the two residual holes.

[0046] The contour feature unit 520 groups adjacent residual holes into a group according to the tunnel circumferential sequence within the cross section to establish the post-blast contour unit. The tunnel circumferential sequence can be determined based on the angular sequence of points within the cross section relative to the design contour centerline or the local coordinates of the section. Its function is to ensure that the grouping of adjacent residual holes conforms to the spatial relationship of the post-blast rock wall 100 continuously unfolding circumferentially. After adjacent residual holes are grouped together, the rock wall points between the two residual holes constitute the inter-hole rock wall.

[0047] The contour feature unit 520 determines the coordinates of the center point of the left residual hole in the cross section as the coordinates of the left hole mark, and the coordinates of the center point of the right residual hole in the cross section as the coordinates of the right hole mark. The coordinates of the left and right hole mark are derived from the position of the geometric center or ellipse fitting center of the residual hole point set within the cross section, and their function is to fix the two ends of the contour unit after the explosion.

[0048] The contour feature unit 520 determines the coordinates of the point with the largest double-hole chord normal distance among the rock wall points between the two residual boreholes as the coordinates of the farthest point on the wall. The coordinates of the farthest point on the wall are used to retain local undulation points in the rock wall between the boreholes that have a direct impact on the over-excavation area and under-excavation area of ​​the cross section. If there are multiple rock wall points with the same maximum double-hole chord normal distance between the two residual boreholes, the point located in the middle of the two residual boreholes in the tunnel circumferential sequence can be selected; if the coordinates of the farthest point on the wall cannot be obtained due to obstruction, this post-blast contour unit is not used for the three-point correspondence group.

[0049] The coordinates of the farthest point on the wall are determined within the vertical slice plane of the corresponding cross-section. The contour feature unit 520 first orthogonally projects the coordinates of the left borehole trace, the right borehole trace, and the rock wall point between the two remaining boreholes onto the same vertical slice plane. Then, the line connecting the projections of the left and right borehole trace coordinates is used as the double borehole chord. The unit direction of the double borehole chord is obtained by subtracting the left borehole trace coordinate from the right borehole trace coordinate and normalizing it according to the distance between the two boreholes.

[0050] ;

[0051] in, Indicates the unit direction of the double-hole chord. Indicates the coordinates of the right hole mark point. Indicates the coordinates of the left hole mark point. This indicates the distance between the two holes. The unit direction of the double-hole chord is a dimensionless directional quantity.

[0052] Within the vertical slice plane, the contour feature unit 520 takes a unit direction perpendicular to the unit direction of the double-hole chord and with an angle not exceeding 90 degrees to the design external normal as the normal direction of the double-hole chord. For the coordinates of any rock wall point between the two remaining holes, the contour feature unit 520 calculates the absolute value of the distance between the coordinates of the rock wall point between the holes and the coordinates of the midpoints at both ends along the normal direction of the double-hole chord, and uses this absolute value of distance as the selection criterion for the coordinates of the farthest point on the wall.

[0053] ;

[0054] in, This represents the normal distance between the two borehole chords corresponding to the coordinates of the rock wall point between the q-th boreholes. This represents the coordinates of the rock wall point between holes q. Indicates the coordinates of the midpoints at both ends. Indicates the normal direction of the double-hole chord. This represents absolute value operations.

[0055] The coordinates of the farthest point on the wall are taken as the coordinates of the rock wall point between the boreholes that maximizes the distance between the two borehole chords. If the distance between the coordinates of multiple rock wall points between the boreholes and the distance between the two borehole chords is the same, the coordinates of the rock wall point between the boreholes that is closest to the midpoint coordinates of both ends along the unit direction of the two borehole chords are selected first; if they are still the same, the coordinates of the rock wall point between the boreholes located in the middle of the set of parallel points in the tunnel circumferential order are selected. If there are fewer than 3 rock wall points between two remaining boreholes, the contour feature unit 520 does not determine the coordinates of the farthest point on the wall, and this post-blast contour unit does not participate in the formation of the three-point correspondence group.

[0056] The design external normal is obtained from the design profile at the midpoint between the two remaining holes, and its direction is a unit vector pointing from the tunnel cavity to the surrounding rock. The design external normal provides a sign direction for the intermediate undulation, so that the coordinates of the farthest point on the wall have a unified directional projection relationship with respect to the coordinates of the midpoints at both ends.

[0057] To form the undulation ratio of the double-hole chord, the contour feature unit 520 first obtains the coordinates of the midpoints at both ends based on the coordinates of the left and right hole traces. The coordinates of the midpoints at both ends are used to represent the midpoint position of the residual holes at both ends of the contour unit after the explosion.

[0058] ;

[0059] in, Indicates the coordinates of the midpoints at both ends. Indicates the coordinates of the left hole mark point. This represents the coordinates of the right borehole trace point. The coordinates of both the left and right borehole trace points are derived from the coordinates of the center point of the residual borehole point set within the cross-section.

[0060] Subsequently, the contour feature unit 520 determines the distance between the coordinates of the left hole mark point and the coordinates of the right hole mark point as the hole spacing. The hole spacing represents the actual geometric width of the post-explosion contour unit between the two residual holes, and is used as the normalization basis for the intermediate undulation amount.

[0061] The distance between the two holes is used for the denominator of the formula and for verifying the width of the profile unit after the explosion. Before calculating the undulation ratio in the double-hole chord, the profile feature unit 520 first determines whether the distance between the two holes is greater than the specified value. If the distance between the two holes is not greater than If the coordinates of the left and right borehole traces cannot constitute a valid adjacent residual borehole, the post-blast profile unit will not calculate the undulation ratio of the double borehole chord. For the spacing between two boreholes that have passed the verification within the same cross section, the profile feature unit 520 also calculates the median of the spacing between the two boreholes; if the spacing between two boreholes is greater than 1.5 times the median of the spacing between the two boreholes, the adjacent residual borehole grouping is determined to be abnormal, and the adjacent residual borehole grouping is re-checked according to the tunnel circumferential sequence.

[0062] ;

[0063] in, Indicates the distance between the two holes. This represents the coordinate difference between the coordinates of the right hole mark point and the coordinates of the left hole mark point. This represents the Euclidean distance operation.

[0064] The contour feature unit 520 defines the directional projection distance of the farthest point coordinate on the wall relative to the midpoint coordinates at both ends along the design external normal as the intermediate undulation amount. When the intermediate undulation amount is positive, it means that the farthest point coordinate on the wall is closer to the surrounding rock side along the design external normal direction relative to the midpoint coordinates at both ends. When the intermediate undulation amount is negative, it means that the farthest point coordinate on the wall is closer to the tunnel cavity side along the opposite direction of the design external normal direction relative to the midpoint coordinates at both ends.

[0065] ;

[0066] in, This indicates the intermediate fluctuations. Indicates the coordinates of the farthest point on the wall. Indicates the coordinates of the midpoints at both ends. This represents the design outward normal used for the post-explosion profile element. This represents the dot product operation.

[0067] The contour feature unit 520 dimensionlessly transforms the intermediate undulation amount relative to the distance between the two holes to obtain the chordal undulation ratio of the two holes. The chordal undulation ratio of the two holes is used to represent the directional undulation of the rock wall between the holes relative to the line connecting the two residual holes. Its value is not output as an engineering report in the over-excavation and under-excavation calculation results 600, but is used by the point cloud registration unit 530 to confirm the corresponding post-blast contour unit and to support the section measurement unit 540 in retaining the coordinates of the farthest point on the wall.

[0068] ;

[0069] in, This indicates the undulation ratio in a double-hole string. This indicates the intermediate fluctuations. This represents the distance between the two pores. The coefficient 2 in the numerator indicates that half of the distance between the two pores is used as the normalization scale.

[0070] The undulation ratio in the double-hole chord exhibits stability under rigid body transformation. When rigid body translation occurs between scanning stations, the coordinates of the left hole mark point, the right hole mark point, and the coordinates of the farthest point on the wall are translated as a whole; when rigid body rotation occurs between scanning stations, the point difference and the design external normal change with the rotation of the same rigid body, while the dot product projection relationship remains consistent.

[0071] If the post-blast contour unit lacks any of the coordinates of the left borehole mark point, the right borehole mark point, the coordinates of the farthest point on the wall, or the design external normal, the contour feature unit 520 can still retain the ordinary rock wall points in that area for subsequent processing, but will not output the post-blast contour unit as a three-point corresponding group source.

[0072] Furthermore, the implementation method of the point cloud registration unit is as follows:

[0073] The point cloud registration unit 530 is used to establish a set of candidate post-blast contour units between scanning stations, compare the difference in undulation ratio in the double-hole chord and uniquely identify the same post-blast contour unit, form a three-point correspondence group from the same post-blast contour units, and form a common target station observation correspondence group and a common target control coordinate correspondence group from the common target station observation correspondence group by merging the three-point correspondence group and the common target station observation correspondence group to obtain the station transformation matrix and perform point cloud fine registration on the fine registration point set, and form the post-blast rock wall point cloud of engineering coordinates according to the common target control coordinate correspondence group.

[0074] The point cloud registration unit 530 first identifies one of the adjacent scanning stations as the reference scanning station and the other as the scanning station to be registered. The reference scanning station provides a reference position for registration between scanning stations, while the scanning station to be registered provides a pre-processed point cloud that needs to be transformed to the relationship of the reference scanning station. For the post-blast contour elements in the overlapping area of ​​the two, the point cloud registration unit 530 sorts them according to the tunnel circumferential direction and assigns them element sequences.

[0075] For each reference post-blast profile unit in the reference scanning station, the point cloud registration unit 530 determines the post-blast profile units in the scanning station to be registered that have the same unit sequence as the reference post-blast profile unit and whose unit sequence is adjacent to each other as candidate post-blast profile units. This candidate range is constrained by the tunnel circumferential order as a priori, which can cover the sequence misalignment caused by slight station deviations and avoids unbounded global search in overlapping areas.

[0076] Point cloud registration unit 530 compares the undulation ratio of each candidate post-blast profile unit with that of the reference post-blast profile unit, and selects the candidate post-blast profile unit with the closest and unique undulation ratio as the corresponding post-blast profile unit. If there are ties for the closest result, point cloud registration unit 530 does not confirm the corresponding post-blast profile unit. This uniqueness rule is used to avoid incorrectly identifying repeated undulations as corresponding post-blast profile units on similar rough rock walls.

[0077] To avoid measurement noise causing instability in the confirmation of post-blast contour units with the same name, the point cloud registration unit 530 sorts the differences in the chordal fluctuation ratio of the candidate post-blast contour units in ascending order. The smallest difference in the chordal fluctuation ratio is denoted as the first difference, and the second smallest difference is denoted as the second difference. The tolerance for the chordal fluctuation ratio difference is taken as the larger of 0.02 and 10% of the standard deviation of the chordal fluctuation ratio of the chordal fluctuation ratio in the overlapping area of ​​the same scanning station.

[0078] ;

[0079] in, This indicates the tolerance for the difference in undulation ratio in a double-hole string. It represents the standard deviation of the undulation ratio in the double-hole chord within the overlapping area of ​​the same scanning station.

[0080] When the number of effective double-hole chord undulation ratios in the overlapping area of ​​the same scanning station is not less than 2, the point cloud registration unit 530 calculates the average value of the double-hole chord undulation ratio and obtains the standard deviation of the double-hole chord undulation ratio according to the sample standard deviation.

[0081] ;

[0082] in, This represents the average ripple ratio in a double-hole string. This indicates the number of effective double-aperture undulation ratios within the overlapping area of ​​the same scanning station. This represents the undulation ratio in the double-hole chord of the j-th effective post-explosion profile element. The average undulation ratio in the double-hole chord is dimensionless.

[0083] ;

[0084] in, This indicates the standard deviation of the ripple ratio in a double-hole string. The number of effective ripple ratios in a double-hole string is not less than [number missing]. When the number of effective double-hole string fluctuation ratios is equal to 1, the tolerance for fluctuation ratio difference in double-hole string is directly taken as 0.02; when the number of effective double-hole string fluctuation ratios is equal to... At that time, the point cloud registration unit 530 did not confirm the same-named burst contour unit.

[0085] Point cloud registration unit 530 only confirms the corresponding candidate post-blast contour unit as a post-blast contour unit of the same name when the difference in the undulation ratio of the first double-hole chord is less than the difference in the undulation ratio of the second double-hole chord minus the tolerance of the difference in the undulation ratio of the double-hole chord. If the set of candidate post-blast contour units contains only one candidate post-blast contour unit, then the difference in the undulation ratio of the first double-hole chord must also not be greater than the tolerance of the difference in the undulation ratio of the double-hole chord. When the set of candidate post-blast contour units is empty or does not meet the above conditions, a post-blast contour unit of the same name is not formed.

[0086] ;

[0087] in, This indicates the difference in the chordal undulation ratio between the candidate post-blast profile element and the reference post-blast profile element. This represents the undulation ratio of the double-hole chord in the candidate post-explosion profile element. This represents the undulation ratio of the double-hole chord of the baseline profile element after the explosion. This represents absolute value operations.

[0088] The point cloud registration unit 530 pairs the left hole mark coordinates, right hole mark coordinates, and farthest point coordinates on the wall of each pair of post-explosion contour units with the same name, forming a three-point correspondence group.

[0089] The common target 300 is used to form two types of correspondences. The common target observation coordinates obtained by adjacent scanning stations for the same common target 300 are paired to form a common target station observation correspondence group; the common target observation coordinates are paired with the corresponding target control coordinates to form a common target control coordinate correspondence group.

[0090] The point cloud registration unit 530 uses the three-point correspondence group and the common target station observation correspondence group as corresponding point pairs in the same rigid body transformation solution, with the goal of reducing the distance residual of all corresponding points after transformation to obtain the station transformation matrix. This rigid body transformation solution can adopt the least squares rigid body registration method commonly used in point cloud registration, and the distance between points remains unchanged during the solution process.

[0091] When solving for the station transformation matrix, the corresponding point pairs in the three-point corresponding group and the corresponding point pairs in the common target station observation corresponding group participate in the same distance residual objective function with equal weight. The number of corresponding point pairs must not be less than 3, and the corresponding point pairs participating in the solution must not all be collinear; if the number of corresponding point pairs is less than 3 or all are collinear, the point cloud registration unit 530 does not calculate the station transformation matrix for that scanning station pair, and retains the preprocessed scanning point cloud of the scanning station to be registered for re-registration with adjacent scanning stations.

[0092] After the station transformation matrix is ​​solved, the point cloud registration unit 530 calculates the distance residual of each corresponding point pair after transformation by the station transformation matrix. If a certain distance residual is greater than 3 times the median of all distance residuals, the corresponding point pair is removed as an abnormal corresponding point, and the station transformation matrix is ​​re-obtained if the remaining corresponding point pairs still meet the quantity and non-collinearity conditions; if the quantity and non-collinearity conditions are not met after removal, the station transformation matrix is ​​not used.

[0093] ;

[0094] in, Represents the station transformation matrix. This represents the rigid body transformation to be solved. This indicates the corresponding point in the scanning station to be registered. Indicates the corresponding point in the reference scanning station. Indicates the number of corresponding point pairs. This represents the squared distance residual of the corresponding point after transformation.

[0095] After obtaining the station transformation matrix, the point cloud registration unit 530 uses the station transformation matrix as the initial transformation to perform fine registration of the finely registered point set. Fine registration employs an iterative nearest-point rigid body transformation, iterating over the finely registered point set within the overlapping area of ​​adjacent scanning stations. With the station transformation matrix as the initial transformation, the iterative nearest-point rigid body transformation begins iterating at a position that closely approximates the true correspondence, thereby reducing the probability of erroneous nearest-point correspondences caused by similar undulations in ordinary rock face points.

[0096] The nearest point search radius for point cloud fine registration is taken as follows The maximum number of iterations is 50. The change in the average distance residual between two adjacent iterations is no greater than [missing value]. At that time, the point cloud registration unit 530 determines that the fine registration of the point cloud has converged and outputs the fine registration incremental transformation.

[0097] Post-explosion contour elements lacking any one of the coordinates of the left hole mark point, the right hole mark point, or the coordinates of the farthest point on the wall will not participate in the formation of the three-point correspondence group.

[0098] The point cloud registration unit 530 first applies the station transformation matrix to the preprocessed scanning point cloud of the scanning station to be registered, and then obtains the fine registration incremental transformation from the point cloud fine registration. The station transformation matrix and the fine registration incremental transformation are combined into the rigid body transformation of adjacent scanning stations.

[0099] ;

[0100] in, Indicates rigid body transformation between adjacent scanning stations. This represents the incremental transformation for fine registration. This represents the station transformation matrix. This expression only indicates the combination relationship of applying the station transformation matrix first and then applying the fine registration incremental transformation.

[0101] Subsequently, the point cloud registration unit 530 obtains the rigid body transformation of the engineering coordinates based on the corresponding group of the common target control coordinates, and applies the rigid body transformation of the engineering coordinates to the preprocessed scan point cloud that has been processed by the rigid body transformation of adjacent scanning stations to form the post-blast rock wall point cloud of engineering coordinates. The position of the design profile in the engineering coordinate system is determined according to the design axis. All the aforementioned transformations keep the distance between points unchanged and do not perform local scaling or bending on the measured point cloud.

[0102] ;

[0103] in, This represents the coordinates of a point in the post-blast rock face point cloud, representing the engineering coordinates. Represents rigid body transformation in engineering coordinates. Indicates rigid body transformation between adjacent scanning stations. This represents the coordinates of a point in the preprocessed scan point cloud of the scanning station to be registered.

[0104] The point coordinates in the formula are represented by homogeneous coordinate column vectors, and the rigid body transformation is represented by a 4×4 homogeneous rigid body transformation matrix. The top-left 3×3 submatrix of the homogeneous rigid body transformation matrix is ​​the rotation matrix, the top-right 3×1 submatrix is ​​the translation vector, and the last row is... The multiplication order in the formula indicates that rigid body transformations of adjacent scanning stations are applied first, followed by rigid body transformations of engineering coordinates.

[0105] The output of point cloud registration unit 530 is the post-blast rock wall point cloud in engineering coordinates. The post-blast rock wall point cloud in engineering coordinates enters the cross-section measurement unit 540 to establish a point-by-point correspondence between the cross-section candidate point set, the measured profile, and the design profile. If the common target 300 is partially occluded but there are still common target station observation correspondence groups and common target control coordinate correspondence groups, the three-point correspondence group can provide the geometric constraints of the post-blast rock wall 100 itself for solving the station transformation matrix; if a certain overlapping area lacks a confirmed post-blast profile unit of the same name, the point cloud registration unit 530 can still use the common target 300 and the fine registration point set to perform conventional rigid body registration, but the undulation ratio of the double hole chord is not used to confirm the corresponding post-blast profile unit in this area.

[0106] Furthermore, the implementation method of the cross-section measurement unit is as follows:

[0107] The cross-section measurement unit 540 is used to project the cross-section of the point cloud of the rock wall after the blasting of the engineering coordinates to construct the measured profile, establish a point-to-point correspondence between the design profile and the measured profile along the design outer normal, and form the over-excavation area and under-excavation area of ​​the cross section according to the profile deviation and the length of the profile segment.

[0108] The cross-section measurement unit 540 establishes a vertical slice plane perpendicular to the design axis at a pre-set cross-section mileage. The cross-section mileage can be pre-set according to the cross-section interval required by the tunnel measurement task. The vertical slice plane is used to transform the three-dimensional engineering coordinate post-blast rock wall point cloud into a two-dimensional point set within the cross-section. The slice thickness limits the range of points taken along the design axis on both sides of the vertical slice plane. Only points within the range of points are included in the formation process of the cross-section candidate point set.

[0109] The cross-sectional mileage is determined according to the design cross-sectional position on the design axis or the fixed cross-sectional interval required by the engineering survey task; the distance between adjacent cross-sections is the axial distance between two adjacent cross-sectional mileages. The slice thickness is taken as... Spacing between adjacent cross sections The larger of the percentages, but not greater than the distance between adjacent cross sections. When the point of the residual hole concentration, the point corresponding to the coordinates of the farthest point on the wall, and the ordinary rock wall point cannot be obtained according to the slice thickness, the cross-section measurement unit 540 can successively expand the slice thickness to the distance between adjacent cross sections. Cross-sectional mileage that still cannot form a candidate point set after expansion is not included in the calculation of cross-sectional over-excavation area and cross-sectional under-excavation area.

[0110] The cross-section measurement unit 540 selects points from the post-blast rock wall point cloud in the engineering coordinates, including points from the residual borehole point set within the sampling range, points corresponding to the coordinates of the farthest point on the wall, and ordinary rock wall points. These selected points are orthogonally projected onto the vertical slicing plane and sorted according to the tunnel circumferential direction to form a cross-section candidate point set. The points in the cross-section candidate point set include both residual borehole-related points and ordinary rock wall points, avoiding the exclusion of borehole boundary marks or local undulations in the rock wall between boreholes from the measured profile during the cross-section measurement stage.

[0111] The cross-section measurement unit 540 orthogonally projects the coordinates of the left hole mark point, the right hole mark point, and the coordinates of the farthest point on the wall onto the vertical slicing plane, forming the coordinates of the left hole mark projection point, the right hole mark projection point, and the farthest point projection point on the wall, respectively. The coordinates of the candidate points in the cross-section and the coordinates of each projection point are all two-dimensional coordinates in the vertical slicing plane.

[0112] The cross-section measurement unit 540 determines the points in the cross-section candidate point set, sorted circumferentially by the tunnel, as contour construction points. These contour construction points are used to form the set of coordinates of the measured contour points.

[0113] The cross-section measurement unit 540 uses the coordinates of the left and right borehole projection points as the boundary points for the inter-bore rock wall segments. Following the tunnel's circumferential arrangement, it delineates inter-bore rock wall segments between adjacent boundary points, ensuring that each boundary point is shared by adjacent inter-bore rock wall segments. This sharing of boundary points guarantees the continuity of inter-bore rock wall segments between adjacent boreholes, preventing discontinuities in the measured profile for the same residual borehole location.

[0114] Within each borehole rock wall segment, the cross-section measurement unit 540 connects the contour construction points point by point in a circumferential sequence along the tunnel, and uses the coordinates of the farthest projection point on the wall as the necessary node for the corresponding borehole rock wall segment. With the coordinates of the farthest projection point on the wall as the necessary node, the measured contour will not smoothly replace the local maximum deviation point of the borehole rock wall due to the zigzag connection or fitting process. After connecting each borehole rock wall segment end to end in sequence, the cross-section measurement unit 540 forms a set of measured contour point coordinates, and the closed measured contour is determined by this set of coordinates.

[0115] If there are many contour construction points in a certain section of the rock wall between holes, they can be connected by broken lines in the circumferential order of the tunnel. If the contour construction points in a certain section of the rock wall between holes are sparsely distributed, they can be connected by segmented broken lines without deleting the coordinates of the left hole trace projection point, the right hole trace projection point, and the coordinates of the farthest projection point on the wall.

[0116] The cross-section measurement unit 540 obtains a unit vector pointing from the tunnel cavity to the surrounding rock as the design outward normal for the coordinates of each design contour point on the design contour. For each design contour point coordinate, the cross-section measurement unit 540 selects the coordinates of the closest and unique intersection point with the actual contour from the intersection points of the straight line passing through the design contour point coordinate and extending along the design outward normal as the coordinates of the corresponding point on the actual contour.

[0117] If a straight line extending along the same design outward normal has multiple intersection points with the measured profile, the section measurement unit 540 selects the coordinates of the closest and unique intersection point to the design profile point coordinates as the coordinates of the corresponding point of the measured profile; if there is no unique intersection point, the coordinates of the design profile point will not participate in the profile deviation calculation at that point, and can be processed according to the existing section measurement rules between adjacent valid design profile point coordinates.

[0118] When a straight line passing through the coordinates of a design profile point and extending along the design outward normal does not intersect with the measured profile, the section measurement unit 540 performs linear interpolation between the coordinates of adjacent valid design profile points before and after that design profile point. The corresponding coordinates of the measured profile point are only added if valid design profile point coordinates exist both before and after that point. If no valid design profile point coordinates exist on either side, the design profile point coordinates are not included in the profile deviation calculation. Linear interpolation is only used to fill in a single missing point and does not span more than two consecutive missing points.

[0119] When the coordinates of two or more consecutive design contour points cannot be obtained from the corresponding coordinates of the measured contour points, the cross-section measurement unit 540 determines the consecutive missing section as an invalid area section. Invalid area sections are not included in the calculation of cross-section over-excavation area and cross-section under-excavation area, and it is not allowed to directly connect the coordinates of the corresponding valid measured contour points on both sides of an invalid area section to form a small contour segment. The length of the small contour segment is determined only between the coordinates of adjacent valid measured contour points or between the coordinates of the corresponding measured contour points supplemented by single-point linear interpolation.

[0120] When a straight line passing through the coordinates of the design profile points and extending along the design outward normal has multiple intersections with the measured profile, the section measurement unit 540 first sorts them according to their distance from the coordinates of the design profile points from smallest to largest; if the distance difference between the nearest intersection point and the second nearest intersection point is greater than... Select the coordinates of the nearest intersection point as the coordinates of the corresponding points on the measured profile; if the distance difference between the nearest intersection point and the second nearest intersection point is no greater than... If the design profile point coordinates do not participate in the profile deviation calculation, they are processed according to the aforementioned linear interpolation rules. If the design external normal coincides with a line segment in the measured profile, the section measurement unit 540 takes the endpoint of the coincident line segment closest to the design profile point coordinates as the intersection point coordinates.

[0121] The cross-section measurement unit 540 determines the profile deviation as the directed projection distance from the coordinates of the design profile points to the coordinates of the corresponding points of the measured profile along the design external normal, and determines the profile segment length as the distance between the coordinates of the corresponding points of adjacent measured profiles. When the profile deviation is positive, the corresponding measured profile deviates outward from the design profile in the direction from the tunnel cavity to the surrounding rock; when the profile deviation is negative, the corresponding measured profile deviates inward from the design profile in the opposite direction.

[0122] ;

[0123] in, Indicates profile deviation. Indicates the coordinates of the points corresponding to the measured profile. Indicates the coordinates of the design outline points. Indicates the design external normal. Indicates the cross-sectional number. Indicates the coordinate sequence number of the design outline point.

[0124] Based on the directional distribution of contour deviation along small contour segments, the cross-section measurement unit 540 classifies the geometric area between the measured contour and the design contour into over-excavation and under-excavation categories. The geometric areas classified as over-excavation are summarized to form the cross-sectional over-excavation area, and the geometric areas classified as under-excavation are summarized to form the cross-sectional under-excavation area. This classification is based on geometric direction and area relationship and does not output a blasting evaluation level.

[0125] Furthermore, the formation methods of the over-excavation / under-excavation area and the volume of the measurement section in the cross-section are as follows:

[0126] Within a cross section, the cross section measurement unit 540 generates the over-excavated area and under-excavated area of ​​the cross section based on the profile deviation and the length of the profile segment. The length of the profile segment can be obtained from the distance between the coordinates of corresponding points of adjacent measured profiles. The directed distribution of the profile deviation on the profile segment is used to determine whether the geometric area corresponding to the profile segment belongs to the over-excavation category or the under-excavation category.

[0127] Before calculating the over-excavation area and under-excavation area of ​​the cross-section, the cross-section measurement unit 540 first checks the sign of the contour deviation of the corresponding points of adjacent measured contours. If the two adjacent contour deviations are one positive and one negative, the coordinates of the zero intersection point are obtained within the contour segment according to the rule that the contour deviation changes linearly along the length of the contour segment, and the original contour segment is divided into two new contour segments using the coordinates of the zero intersection point; if one of the two adjacent contour deviations is zero, then that point is directly used as the boundary between the over-excavation classification and the under-excavation classification. After the above division is completed, each contour segment in the formula does not cross the position where the contour deviation sign changes.

[0128] ;

[0129] in, Indicates the first The over-excavation area of ​​each cross section. and This represents the contour deviation between the two ends of the same contour segment after the zero-intersection segmentation is completed. This indicates the length of the small segment of the outline. and This indicates that only positive profile deviations are included in the over-excavation classification.

[0130] ;

[0131] in, Indicates the first The area of ​​under-excavation in the cross-section of each cross section. and This represents the contour deviation between the two ends of the same contour segment after the zero-intersection segmentation is completed. This indicates the length of the small segment of the outline. and This indicates that only the absolute contribution of negative contour deviation is included in the under-dug classification.

[0132] The computing device 500 processes adjacent cross sections one by one according to the mileage sequence of the cross sections on the design axis. The distance between adjacent cross sections is obtained from the axial distance between adjacent cross section mileages. The computing device 500 performs piecewise numerical integration along the design axis based on the over-excavation area, under-excavation area, and distance between adjacent cross sections for each pair of adjacent cross sections.

[0133] ;

[0134] in, Indicates the over-excavation volume of the measurement section. and These represent the over-excavation areas of two adjacent cross sections. This indicates the distance between adjacent cross sections.

[0135] ;

[0136] in, Indicates the under-excavation volume of the measured section. and These represent the under-excavation areas of two adjacent cross sections. This indicates the distance between adjacent cross sections.

[0137] The computing device 500 summarizes the numerical integration results of the over-excavation segments to form the over-excavation volume of the measurement section, and summarizes the numerical integration results of the under-excavation segments to form the under-excavation volume of the measurement section. The over-excavation and under-excavation calculation results 600 include at least the over-excavation area of ​​the cross section, the under-excavation area of ​​the cross section, the over-excavation volume of the measurement section, and the under-excavation volume of the measurement section.

[0138] As an optional implementation, the common target 300 is visible, and the adjacent residual holes on the post-blast rock wall 100 are clearly visible. The 3D laser scanner 200 can acquire the common target 300 and the post-blast rock wall 100 in the overlapping area at adjacent scanning stations. The point cloud preprocessing unit 510 can stably form a set of residual hole points and ordinary rock wall points, and the contour feature unit 520 can obtain the coordinates of the left hole mark point, the coordinates of the right hole mark point, the coordinates of the farthest point on the wall, and the design external normal for multiple post-blast contour units. The point cloud registration unit 530 confirms the corresponding post-blast contour units by the undulation ratio of the double hole chord and obtains the station transformation matrix by combining the observations of the corresponding group at the common target station. After the cross-section measurement unit 540 forms the measured contour, the over-excavation and under-excavation calculation results 600 outputs the over-excavation area and under-excavation area of ​​each cross section.

[0139] As an optional implementation, the ordinary rough surface of the post-blast rock wall 100 has similar undulations in adjacent scanning stations, and simply relying on the nearest point relationship can easily lead to mismatching of rock walls between adjacent boreholes. In this case, the undulation ratio of the double borehole chord calculated by the contour feature unit 520 is used to confirm the corresponding post-blast contour unit in the point cloud registration unit 530. Since the undulation ratio of the double borehole chord includes the coordinates of the left borehole mark point, the coordinates of the right borehole mark point, the coordinates of the farthest point on the wall, and the directed relationship formed by the design outward normal, the point cloud registration unit 530 can select the corresponding post-blast contour unit with the closest and unique value from the candidate post-blast contour unit set.

[0140] As an optional implementation, if the ordinary contour fitting tends to smooth the rock wall between holes, the coordinates of the farthest projection point on the wall surface serve as a constraint, acting as a necessary node for the corresponding rock wall segment between holes. The cross-section measurement unit 540 connects the contour construction points point by point in a circumferential sequence along the tunnel, and retains the coordinates of the left hole mark projection point, the right hole mark projection point, and the coordinates of the farthest projection point on the wall surface. This ensures that the measured contour reflects the local undulations of the rock wall between holes, thereby making the over-excavated area and under-excavated area of ​​the cross-section closer to the scanning results of the post-blast rock wall point cloud in engineering coordinates.

[0141] As an optional implementation, if a common target station observation correspondence group and a common target control coordinate correspondence group can still be formed, the point cloud registration unit 530 can continue to use the three-point correspondence group and the common target station observation correspondence group together to solve the station transformation matrix. If a certain common target 300 is not visible in the scanning station to be registered, then the common target 300 does not participate in the corresponding common target station observation correspondence group, and the point cloud registration unit 530 uses the remaining valid correspondence relationships to solve the rigid body transformation.

[0142] As an optional implementation, if a post-blast contour unit lacks any one of the coordinates of the left borehole mark point, the right borehole mark point, or the coordinates of the farthest point on the wall, the post-blast contour unit will not participate in the formation of the three-point correspondence group. This local missing measurement does not cause the entire scanning station data to be deleted; the point cloud preprocessing unit 510 still retains the ordinary rock wall points in this area, the point cloud registration unit 530 can still perform point cloud fine registration on the fine registration point set, and the cross-section measurement unit 540 forms the measured contour based on the effective cross-section candidate point set.

[0143] It should be noted that the computing device 500 can be an industrial control computer, workstation, or portable computer capable of running point cloud processing programs.

[0144] Although embodiments of this application have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of this application, and all such modifications and variations fall within the scope defined by the appended claims.

Claims

1. A dual-energy blasting profile over- and under-excavation calculation system based on point cloud registration, comprising a 3D laser scanner, a common target, and a computing device for storing the design profile and target control coordinates, characterized in that, The computing device is equipped with a point cloud preprocessing unit, a contour feature unit, a point cloud registration unit, and a cross-section measurement unit; The point cloud preprocessing unit generates preprocessed scan point clouds, residual borehole point sets, ordinary rock wall point sets, and finely registered point sets from the original scan point cloud; The contour feature unit is established by using adjacent residual holes and rock walls between holes to establish the post-blast contour unit, and obtains the coordinates of the left hole trace point, the right hole trace point, the coordinates of the farthest point on the wall and the design external normal. The undulation ratio of the double hole chord is a directed dimensionless feature quantity that characterizes the amount of undulation in the middle relative to the distance between the two holes. The point cloud registration unit establishes a set of candidate post-blast contour units between scanning stations, compares the difference in undulation ratio in the double-hole chord and uniquely confirms the same post-blast contour unit, forms a three-point correspondence group from the same post-blast contour units, forms a common target station observation correspondence group and a common target control coordinate correspondence group from the common target station observation correspondence group, merges the three-point correspondence group and the common target station observation correspondence group to obtain the station transformation matrix and performs point cloud fine registration on the fine registration point set, and forms an engineering coordinate post-blast rock wall point cloud according to the common target control coordinate correspondence group; The cross-section measurement unit projects the cross-section of the point cloud of the rock wall after the blasting of the engineering coordinates to construct the measured profile. It establishes a point-to-point correspondence between the design profile and the measured profile along the design outer normal and forms the over-excavation area and under-excavation area of ​​the cross section according to the profile deviation and the length of the profile segment. The calculation equipment integrates the over-excavated area and under-excavated area of ​​the cross section according to the distance between adjacent cross sections to form the over-excavated volume and under-excavated volume of the measurement section.

2. The dual-energy blasting contour over- and under-excavation calculation system based on point cloud registration according to claim 1, characterized in that, The point cloud preprocessing unit removes outliers from the original scanned point cloud through statistical filtering. It then calculates the local curvature and local point density of each point within the filtered original scanned point cloud, selecting candidate residual borehole points that simultaneously satisfy both the residual borehole surface curvature and point density conditions. Spatial clustering is performed on these candidate residual borehole points, and ellipse fitting is applied to each cluster. The clusters whose fitting residuals satisfy the residual borehole fitting conditions are designated as the residual borehole point set. The residual borehole point set and the rock wall points between adjacent residual boreholes are designated as the retention set. Rock wall points outside the retention set are designated as ordinary rock wall points. Voxel downsampling is performed only on the ordinary rock wall points. The retention set and the downsampled ordinary rock wall points are merged to form the preprocessed scanned point cloud. Ordinary rock wall points within the overlapping area of ​​adjacent scan stations are designated as the fine-calibration point set.

3. The dual-energy blasting profile over- and under-excavation calculation system based on point cloud registration according to claim 1, characterized in that, The contour feature unit is established by pairing adjacent residual holes in the tunnel circumferential sequence within the cross section to create a post-blast contour unit. The coordinates of the center point of the left residual hole in the cross section are determined as the coordinates of the left hole trace point, and the coordinates of the center point of the right residual hole in the cross section are determined as the coordinates of the right hole trace point. The coordinates of the point on the rock wall between the two residual holes with the largest normal distance relative to the line connecting the coordinates of the left and right hole trace points are determined as the coordinates of the farthest point on the wall. The unit vector from the tunnel cavity to the surrounding rock is obtained from the design contour at the middle position of the two residual holes as the design external normal. The distance between the coordinates of the left and right hole trace points is determined as the distance between the two holes. The directional projection distance of the coordinates of the farthest point on the wall relative to the midpoint of the coordinates of the left and right hole trace points along the design external normal is determined as the intermediate undulation amount. The undulation ratio of the double hole chord is a directional dimensionless characteristic quantity representing the intermediate undulation amount relative to the distance between the two holes.

4. The dual-energy blasting contour over- and under-excavation calculation system based on point cloud registration according to claim 3, characterized in that, The point cloud registration unit determines one of the adjacent scanning stations as the reference scanning station and the other as the scanning station to be registered. It sorts the post-blast contour units in the overlapping area of ​​the two stations according to the tunnel circumferential direction and assigns them unit positions. For each reference post-blast contour unit in the reference scanning station, it determines the post-blast contour units in the scanning station to be registered that have the same unit position as the reference post-blast contour unit and those adjacent to it in the unit position as the candidate post-blast contour unit set. It compares the undulation ratio of the double hole chord of each candidate post-blast contour unit with that of the reference post-blast contour unit, and selects the candidate post-blast contour unit with the closest and unique undulation ratio of the double hole chord as the same-name post-blast contour unit. If there are ties for the closest result, the same-name post-blast contour unit is not confirmed.

5. The dual-energy blasting contour over- and under-excavation calculation system based on point cloud registration according to claim 4, characterized in that, The point cloud registration unit pairs the left hole mark coordinates, right hole mark coordinates, and farthest point coordinates on the wall for each pair of post-blast contour units with the same name, forming a three-point correspondence group; it pairs the common target observation coordinates obtained by adjacent scanning stations for the same common target, forming a common target station observation correspondence group; it pairs each common target observation coordinate with the corresponding target control coordinate, forming a common target control coordinate correspondence group; the three-point correspondence group and the common target station observation correspondence group are used together as corresponding point pairs in the same rigid body transformation solution, with the goal of reducing the distance residual after transformation of all corresponding points to obtain the station transformation matrix, and the station transformation matrix is ​​used as the initial transformation to perform point cloud fine registration on the fine registration point set. The point cloud fine registration adopts iterative nearest point rigid body transformation; post-blast contour units lacking any one of the left hole mark coordinates, right hole mark coordinates, or farthest point coordinates on the wall do not participate in the formation of the three-point correspondence group.

6. The dual-energy blasting profile over- and under-excavation calculation system based on point cloud registration according to claim 5, characterized in that, The point cloud registration unit first applies the station transformation matrix to the preprocessed scanning point cloud of the scanning station to be registered, then obtains the fine registration incremental transformation from the point cloud fine registration, and combines the station transformation matrix and the fine registration incremental transformation into the rigid body transformation of adjacent scanning stations. Subsequently, the engineering coordinate rigid body transformation is obtained according to the corresponding group of common target control coordinates, and the engineering coordinate rigid body transformation is applied to the preprocessed scanning point cloud processed by the rigid body transformation of adjacent scanning stations to form the engineering coordinate post-blast rock wall point cloud. The position of the design contour in the engineering coordinate system is determined according to the design axis, and the distance between points remains unchanged in all the aforementioned transformations.

7. The dual-energy blasting profile over- and under-excavation calculation system based on point cloud registration according to claim 1, characterized in that, The cross-section measurement unit establishes a vertical slicing plane perpendicular to the design axis at a pre-set cross-section mileage along the design axis. The slicing thickness limits the range of points to be taken along the design axis on both sides of the vertical slicing plane. Points in the residual borehole point set, points corresponding to the coordinates of the farthest point on the wall, and ordinary rock wall points within the point range are selected from the post-blast rock wall point cloud of engineering coordinates. The selected points are orthogonally projected onto the vertical slicing plane and sorted according to the tunnel circumferential direction to form a cross-section candidate point set. The coordinates of the left borehole mark point, the right borehole mark point, and the coordinates of the farthest point on the wall are orthogonally projected onto the vertical slicing plane to form the coordinates of the left borehole mark projection point, the right borehole mark projection point, and the coordinates of the farthest projection point on the wall, respectively. The coordinates in the cross-section candidate point set and the coordinates of each projection point are all two-dimensional coordinates in the vertical slicing plane.

8. The dual-energy blasting profile over- and under-excavation calculation system based on point cloud registration according to claim 7, characterized in that, The cross-section measurement unit determines the points in the cross-section candidate point set, which are sorted in the tunnel circumferential direction, as contour construction points. The coordinates of the left and right borehole trace projection points are used as the boundary points of the inter-hole rock wall segments. Inter-hole rock wall segments are delineated between adjacent boundary points according to the tunnel circumferential direction, so that each boundary point is shared by the adjacent inter-hole rock wall segments. Within each inter-hole rock wall segment, the contour construction points are connected point by point according to the tunnel circumferential direction. The coordinates of the farthest projection point on the wall surface are used as the necessary nodes of the corresponding inter-hole rock wall segment. The inter-hole rock wall segments are connected end to end to form a set of measured contour point coordinates, and the closed measured contour is determined by the set of measured contour point coordinates.

9. The dual-energy blasting profile over- and under-excavation calculation system based on point cloud registration according to claim 8, characterized in that, The cross-section measurement unit obtains a unit vector pointing from the tunnel cavity to the surrounding rock as the design outward normal for each design contour point coordinate on the design contour. From the intersection points of the straight line passing through the design contour point coordinates and extending along the design outward normal and the measured contour, the coordinates of the closest and unique intersection point to the design contour point coordinates are selected as the coordinates of the corresponding point on the measured contour. The directed projection distance from the design contour point coordinates to the corresponding point coordinates of the measured contour along the design outward normal is determined as the contour deviation. The distance between the coordinates of adjacent corresponding points on the measured contour is determined as the length of the contour segment. Based on the directed distribution of the contour deviation on the contour segment, the geometric area between the measured contour and the design contour is classified as over-excavation and under-excavation. The geometric areas classified as over-excavation are summarized to form the cross-sectional over-excavation area, and the geometric areas classified as under-excavation are summarized to form the cross-sectional under-excavation area.

10. The dual-energy blasting profile over- and under-excavation calculation system based on point cloud registration according to claim 9, characterized in that, The computing device processes adjacent cross sections one by one in chronological order of the cross-sectional mileage on the design axis. Based on the over-excavation area, under-excavation area, and distance between adjacent cross sections of each pair of adjacent cross sections, it performs segmented numerical integration along the design axis. The over-excavation segmented numerical integration results are summarized to form the over-excavation volume of the measurement section, and the under-excavation segmented numerical integration results are summarized to form the under-excavation volume of the measurement section.

Images