Hole detection method, explosive loading method, hole detector, and program

Abstract

To improve a detection accuracy of a drilled hole.SOLUTION: A hole detection method executed by a computer comprises: acquiring depth data of an object including an excavated surface and a hole opening of a hole drilled in the excavated surface from a distance image sensor; scanning the depth data to detect an edge of the hole opening; and estimating a center coordinate of the hole opening based on the detected edge.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a technique for accurately detecting blast holes drilled in a tunnel face in a tunnel constructed by a blasting method. [Background technology]

[0002] The blasting method is known as a tunnel excavation method. When excavating a tunnel using this method, explosives with detonators attached are inserted into multiple blast holes (charge holes) drilled into the tunnel face, and the explosives are detonated to explode the explosives and excavate the tunnel face.

[0003] In the past, at tunnel construction sites where blasting was used, workers generally loaded explosives into the blast holes manually. This loading work required workers to push explosives into the blast holes one by one using a long rod, which was very hard work.

[0004] For this reason, a technique has been proposed in which explosives for detonation (hereinafter sometimes referred to as "parent die" (parent dynamite)) and additional explosives for increasing the explosive power at the time of blasting (hereinafter sometimes referred to as "additional die" (additional dynamite)) are loaded into a blast hole from a position away from the face using a hose or pipe (see, for example, Patent Documents 1 to 4, etc.). This type of explosive loading technique is also called mechanical loading (remote loading), etc. In such mechanical loading, for example, a worker on a rack (cage) of a drill jumbo inserts the tip of a loading pipe into a blast hole drilled in the face, and compresses compressed air from a loading machine provided at the base end of a hose connected to the loading pipe toward the tip of the loading pipe, and the parent die and additional die are loaded into the charge hole together with the compressed air by the loading pipe. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 2860847 [Patent Document 2] Patent No. 5614139 [Patent Document 3] Patent No. 5854923 [Patent Document 4] JP 2008-25972 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, the conventional explosive loading device has room for improvement in terms of the accuracy with which explosives are loaded into a blast hole using a loading rod.

[0007] The present invention has been made in consideration of the above-mentioned problems, and has an object to provide a technique for improving the accuracy of detecting drilled holes. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention includes the following aspects. (Aspect 1) Obtaining depth data of an object including an excavation surface and an opening of a borehole drilled in the excavation surface from a range image sensor; scanning the depth data to detect edges of the aperture; estimating center coordinates of the hole mouth based on the detected edges; The computer performs the hole detection method. (Aspect 2) the scanning includes a first scan along a first direction and a second scan along a second direction orthogonal to the first direction; The center coordinates are obtained as a center when the detected edge is symmetrical in the first direction and the second direction. 2. The hole detection method according to claim 1. (Aspect 3) The inclination of the excavation surface is estimated based on the depth data after removing outliers from the depth data, and the depth data of the object is corrected; A position where the depth of the excavation surface is greater than or equal to a predetermined threshold is detected as a candidate for the edge. 3. The hole detection method according to claim 1 or 2. (Aspect 4) This is done by clustering the edge candidates based on the position with the greatest depth and removing noise from the edge candidates. 4. The pore detection method according to embodiment 3. (Aspect 5) The distance image sensor is a ToF (Time of Flight) type sensor. A hole detection method according to any one of aspects 1 to 4. (Aspect 6) The drilling hole is a blasting hole drilled on a face of a tunnel by a blasting method, holding the explosive charge with a loading rod; A step of loading an explosive mounting body held by the loading rod into the blast hole with the center coordinate estimated by the hole detection method according to any one of aspects 1 to 5 as a target; A method of loading explosives comprising: (Aspect 7) A hole detection device comprising a processor for executing the hole detection method according to any one of aspects 1 to 5. (Aspect 8) A program for causing a computer to execute the hole detection method according to any one of aspects 1 to 5.

[0009] The contents described in the Means for Solving the Problems can be combined as much as possible without departing from the problem and technical idea of ​​the present invention. The contents of the means for solving the problem can be provided as an apparatus such as a computer or a system including multiple apparatuses, a method executed by a computer, or a program executed by a computer. The program can also be executed on a network. A recording medium holding the program may also be provided. Effect of the Invention

[0010] According to the present invention, a technique for improving the detection accuracy of the blast hole position can be provided. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram illustrating the overall configuration of an explosive loading system. [Diagram 2] FIG. 2 is a front view showing an example of the arrangement of multiple blast holes formed on a working face. [Diagram 3] FIG. 3 is a diagram illustrating the equipment mounted on the heavy machinery for loading charges. [Figure 4] FIG. 4 is a diagram showing a procedure flow of explosives loading control. [Diagram 5] FIG. 5 is a diagram showing a procedure flow of the hole detection process. [Figure 6] FIG. 6 is a schematic cross-sectional view for explaining capturing of a distance image. [Figure 7] FIG. 7 is a schematic diagram showing the magnitude of distance (depth). [Figure 8] FIG. 8 is a schematic diagram showing an example of a distance image after the outliers have been removed. [Figure 9] FIG. 9 is a diagram showing an example of a distance image after correction. [Figure 10] FIG. 10 is a diagram showing an example of the distance image after correction. [Figure 11] FIG. 11 is a diagram for explaining the detection of the edge of a hole. [Figure 12] FIG. 12 is a diagram showing an example of candidate points after clustering. [Figure 13] FIG. 13 is a diagram for explaining the estimation of the center. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that each configuration and combination thereof in the embodiment is merely an example, and addition, omission, substitution, and other modifications of the configuration are possible as appropriate within the scope of the gist of the present invention.

[0013] <Embodiment 1> FIG. 1 is a diagram for explaining the overall configuration of an explosive loading system S according to the first embodiment. The explosive loading system S is applied to a blasting method for blasting a face (rock) 2 of a tunnel TN with explosives, and is a system for loading explosives into a plurality of blasting holes (charge holes) 3 for blasting drilled in the face 2. The tunnel TN is constructed by a blasting method in which explosives with detonators are inserted into each blasting hole 3 drilled in the face 2, and the explosives are detonated to excavate the face 2. The blasting holes 3 in the face 2 can be drilled in the face 2 to a predetermined drilling depth by a drilling device of a construction heavy machine such as a drill jumbo.

[0014] The explosive loading system S includes a heavy machine for loading explosives 10 and a working vehicle 200. The heavy machine for loading explosives 10 is a construction heavy machine for loading explosives into a blast hole 3 using an explosive loading device 1, and is equipped with the explosive loading device 1. The heavy machine for loading explosives 10 is equipped with a dolly 11 for self-propelling, a drilling boom 12 provided on the front side of the dolly 11, an explosive loading boom 13, a driver's seat 14, a control device 15, a rock drilling machine 19, a driving power unit (not shown), and the like. In addition, a working vehicle 200 is arranged on the rear side of the heavy machine for loading explosives 10 with respect to the face 2. In addition, an additional explosive supply device 83 is mounted on the loading platform of the working vehicle 200. The heavy machine for loading explosives 10 and the working vehicle 200 may be an integrated device. In addition, at least one of the heavy machine for loading explosives 10 and the working vehicle 200 may be a so-called robot-shaped device.

[0015] A rock drilling machine 19 is rotatably supported on the drilling boom 12 of the heavy equipment for loading 10. The rock drilling machine 19 can be, for example, an existing drilling device that drills blast holes 3 in the face 2 (rock) by the striking motion and rotational action of a drilling drill. The heavy equipment for loading 10 will be described as a heavy equipment equipped with an explosive loading device 1 on a drill jumbo having a rock drilling machine 19 for drilling blast holes 3 in the face 2, but it may be a heavy equipment without the rock drilling machine 19. When the heavy equipment for loading 10 does not have the rock drilling machine 19, the blast holes 3 are drilled by another heavy equipment or a device such as a robot having the rock drilling machine 19.

[0016] The explosive loading boom 13 of the explosive loading heavy machine 10 has a boom body 16 rotatably connected to the front end side of the dolly 11, a guide shell 17 connected to the tip side of the boom body 16, and a loading rod 18. The boom body 16 can freely extend, retract, tilt, swing, rotate, etc. by an appropriate driving mechanism. In addition, the boom body 16 is provided with a driving mechanism (not shown) for driving the guide shell 17, and this driving mechanism allows the guide shell 17 to freely swing in the horizontal direction, swing in the vertical direction, and move forward and backward in the front and rear directions. In this embodiment, a plurality of explosive loading booms 13 are mounted on the explosive loading heavy machine 10, but the number of explosive loading booms 13 to be mounted is not particularly limited. The loading rod 18 is a long hollow pipe extending in one direction, and a hollow passage is formed inside. The loading rod 18 is a pipe having appropriate rigidity and flexibility, and may be made of, for example, resin. The loading rod 18 is fed in the extension direction by a loading rod feeding mechanism 80. When explosives are loaded into the blast hole 3 using the explosive loading device 1, the front end side of the loading rod 18 is connected to the explosive for detonation. By inserting it into the explosive supply device 70, the holding jig provided on the loading rod 18 holds one of the multiple parent die attachments housed in the explosive supply device 70 for detonation. Then, the loading rod 18 can insert the parent die attachment 5 attached to the holding jig into the blast hole 3.

[0017] Fig. 2 is a front view showing an example of the arrangement of multiple blast holes 3 formed in the working face 2. Here, an example will be described in which a staged blasting method is used to excavate the working face 2. The staged blasting method is a method in which multiple blasting target areas are set on the working face 2, and blasting is performed by setting a time difference in the detonation timing of the detonator that detonates the explosive for each of the multiple blasting target areas that have been set.

[0018] The symbols #1 to #10 shown in FIG. 2 indicate the stages to which the multiple blast holes 3 belong (corresponding to the blast holes 3). In this embodiment, multiple blasting target areas are set on the face 2, and stages corresponding to each blasting target area are assigned (set). In the example shown in FIG. 2, 10 types of blasting target areas are set on the face 2, and the first stage #1 to the tenth stage #10 are assigned to each blasting target area. In FIG. 2, in order to make it easier to understand the distribution of each stage #1 to #10 on the face 2, when blasting holes 3 belonging to the same stage are close to each other, the blasting hole groups are connected by dashed lines. However, there are no particular limitations on the arrangement pattern of the blasting holes 3 shown in FIG. 2, the number of stages, and the number of blasting holes 3 belonging to each stage.

[0019] The control device 15 of the explosive loading heavy machine 10 may be a computer fixed to the cockpit 14, or may be a detachable computer such as a tablet terminal. The control device 15 controls the explosive loading device 1 and the additional explosive supply device 83 to perform explosive loading control.

[0020] FIG. 3 is a diagram illustrating the equipment mounted on the explosive charge heavy machine 10. FIG. 3 particularly shows some of the equipment connected to the control device 15. The cockpit 14 is provided with a monitor (display device) 210, the control device 15, and input devices to the control device 15 (explosive charge remote control switch 231, operation panel 232, keyboard 233, pointing device 234, etc.). In addition, the above-mentioned guide shell 17 or an alignment mechanism mounted on the guide shell 17 is provided with a hole detection device 250 and a ToF (Time of Flight) sensor 270. The hole detection device 250 includes a depth camera 253 and captures an image of the blast hole 3 to be loaded on the face 2. The ToF sensor 270 is used for final confirmation that the blast hole 3 exists in the explosive charge loading direction X (FIG. 1), which is the direction in which the loading rod 18 loads the parent die attachment. The heavy equipment for explosives 10 allows an operator to use various devices of the input device to operate the drilling boom 12, the explosives loading boom 13, the guide shell 17, the rock drill 19, the explosives loading device 1, the additional explosives supply device 83, and the like in the heavy equipment for explosives 10. In addition, in explosives loading control, the control device 15 can control the explosives loading boom 13, the guide shell 17, the explosives loading device 1, and the like to automatically load a parent die and an additional die into the blast hole 3 drilled in the face 2.

[0021] The control device 15 is, for example, a computer including a processor 151 and a storage device 152. The processor 151 is an arithmetic processing device such as a CPU (Central Processing Unit). The processor 151 executes the programs to perform each process according to this embodiment. The processor 151 also transmits and receives data to and from the hole detection device 250. The storage device 152 may be at least some of a main storage device such as a random access memory (RAM) or a read only memory (ROM), and an auxiliary storage device (secondary storage device) such as a hard disk drive (HDD), a solid state drive (SSD), an embedded multi-media card (eMMC), or a flash memory. The main storage device temporarily stores the program read by the processor 151 and information transmitted and received between other devices, and secures a working area for the processor 151. The auxiliary storage device stores the program executed by the processor 151, information transmitted and received between other devices, and design information including the position and size of the blast holes 3 to be formed in the face 2. .

[0022] The hole detection device 250 is a computer including a processor 251, a storage device 252, and a depth camera (distance image camera) 253. The processor 251 is an arithmetic processing device such as a CPU, and executes a program to perform each process according to this embodiment. The processor 251 also acquires data output by the depth camera 253 via a predetermined interface, estimates the hole position using the depth information, and transmits information of the estimated coordinates to the control device 15. The storage device 252 may be at least one of a main storage device such as a RAM or a ROM, and an auxiliary storage device such as an HDD, an SSD, an eMMC, or a flash memory. The main storage device temporarily stores the program read by the processor 251 and information transmitted and received between other devices, and secures a working area for the processor 251. The auxiliary storage device stores the program executed by the processor 251, information transmitted and received between other devices, and the like. The depth camera 253 is a camera with a depth sensor (distance image sensor). The depth sensor can measure the distance to the surface of the imaging target and output the magnitude of the distance, for example, as a heat map. That is, the depth camera 253 outputs a distance image including depth data (distance information) corresponding to each pixel in the imaging range.

[0023] Hereinafter, the procedure of explosive loading control executed by the explosive loading system S will be described. FIG. 4 is a diagram showing a procedure flow of explosive loading control executed by the control device 15 of the explosive loading system S. First, as shown in FIG. 1, the dolly 11 of the heavy equipment for loading charges 10 is run and moved close to the face 2 to be blasted, and a plurality of blast holes 3, 3, ... of a predetermined length are drilled by driving the drilling boom 12 and the rock drilling machine 19 at the planned drilling positions of the face 2 according to the blasting pattern (FIG. 4: step S1). The control device 15 associates identification information such as a hole number with each of the blast holes 3 when drilling the blast holes 3 with the rock drilling machine 19 of the heavy equipment for loading charges 10, or in advance. Then, for each hole number of the blast holes 3, the blast hole position information including the three-dimensional coordinate values ​​of the first coordinate P1 (X1, Y1, Z1) of the hole mouth 3B corresponding to the hole number and the second coordinate P2 (X2, Y2, Z2) of the innermost part 3A, and the blast hole stage number information regarding the stage number of the blast hole 3 corresponding to the hole number are stored in the storage device 152 (storage process). The heavy equipment for loading 10 may be a fully automatic drill jumbo (also called a "computer drill jumbo"), and the blast holes 3 may be drilled sequentially at the planned drilling positions of the face 2 by automatically controlling the drilling boom 12 and the rock drilling machine 19 based on the planned drilling position information of the blast holes 3 stored in the storage device 152 of the control device 15. In the example shown in Fig. 2, the first stage #1 to the tenth stage #10 are assigned to each blasting target area on the face 2, and in step S1, the first stage blasting holes 3 (#1) to the tenth stage blasting holes 3 (#10), each including one or more blasting hole groups, are drilled for the first stage #1 to the tenth stage #10 of the face 2. In addition, parent dies with detonation seconds set in correspondence with each stage are inserted into the first stage blasting holes 3 (#1) to the tenth stage blasting holes 3 (#10).

[0024] Next, by operating an input device (e.g., an operation panel 232), the explosives loading boom 13 is placed near the face 2 where the blast holes 3 have been drilled. Also, as shown in FIG. 1, a work vehicle 200 is placed behind the heavy equipment 10 for loading explosives, and a predetermined amount of additional dies is put into the hopper of the additional explosives supply device 83.

[0025] Next, in step S2, the control device 15, under computer control, refers to blast hole position information including three-dimensional coordinate values ​​of the first coordinate P1 (X1, Y1, Z1) and second coordinate P2 (X2, Y2, Z2) of the blast hole 3 corresponding to the hole number previously set, and automatically drives the explosives loading boom 13 of the explosives loading heavy machine 10, etc., to align the loading rod 18 so that the tip of the loading rod faces coaxially with the blast hole 3 to be loaded with explosives (parent die and additional die) among the blast holes 3 drilled at multiple locations on the face 2. As described above, the control device 15 determines the first coordinate P1 (X1 , Y1, Z1) and the second coordinate P2 (X2, Y2, Z2) of the innermost part 3A are associated with the hole number, and blast hole stage number information relating to the stage number of the blast hole 3 corresponding to the hole number is stored in the storage device 152 in association with each other. Therefore, the control device 15 can align the loading rod 18 so that the tip of the loading rod 18 is approximately opposed to the blast hole 3 to be loaded by referring to this blast hole position information and reading out the first coordinate P1 (X1, Y1, Z1) and second coordinate P2 (X2, Y2, Z2) corresponding to the blast hole 3 to be loaded. Note that there may be an error of, for example, several tens of millimeters between the coordinates (first coordinate P1 or second coordinate P2) of the blast hole 3 stored in the blast hole information of the storage device 152 and the position of the blast hole 3 that was actually drilled. Therefore, in this embodiment, the center coordinate of the blast hole 3 is acquired from the hole detection device 250 to improve the accuracy of alignment.

[0026] FIG. 5 is a diagram showing a procedure flow of the hole detection process executed by the hole detection device 250. The processor 251 of the hole detection device 250 acquires a distance image captured by the depth camera 253 (FIG. 5: S11). FIG. 6 is a schematic cross-sectional view for explaining the capture of a distance image. FIG. 6 is a diagram showing the face 2 cut horizontally and the depth camera 253 viewed from above. Since the position where the blast hole 3 is drilled on the face 2 is known, the processor 251 can control the explosive loading boom 13 and the like to capture a distance image including the blast hole 3 to be loaded. In this embodiment, the description will be given assuming that the distance image includes one blast hole 3. The distance image including one blast hole 3 may be created by trimming the distance image output by the depth camera 253. In addition, as the coordinate axes are indicated by arrows in FIG. 6, the horizontal (e.g., horizontal) direction of the captured distance image is called the X-axis direction, the vertical (e.g., vertical) direction is called the Y-axis direction, and the depth (depth) direction is called the Z-axis direction. Fig. 7 is a schematic diagram showing the magnitude of distance (depth) at a given height (Y coordinate where blast hole 3 is located) in a distance image. In the graph of Fig. 7, the horizontal axis represents the position on the X axis, and the vertical axis represents the magnitude of distance (depth) in the depth direction. In the distance image, the depth of blast hole 3 is large, and the surface of the face 2 shows actual irregularities and changes in depth due to noise.

[0027] The processor 251 also removes outliers (FIG. 5: S12). In this step, the processor 251 may take a moving average of depth information for the distance image acquired in S11, for example, in a predetermined scanning direction, and remove the depth information when the depth changes beyond a criterion. Also, for example, based on an existing function of the depth camera 253, depth information whose reliability value is lower than a predetermined criterion may be removed. FIG. 8 is a schematic diagram showing an example of a distance image after removing outliers. In FIG. 8, the horizontal axis also represents the position on the X axis, and the vertical axis represents the magnitude of the distance (depth). In this step, the depth information roughly along the face 2 is left. Note that the result of this step is used to correct the inclination of the depth of the face 2, so that the depth information corresponding to the inside of the blast hole 3 may be removed.

[0028] Next, the processor 251 corrects the inclination of the depth of the face 2 (FIG. 5: S13). In this step, the processor 251 estimates the depth information of the distance image acquired in S11 when the distance image is captured facing the face 2. Specifically, the processor 251 first obtains an approximate plane of the face 2 using the distance image after removing the outliers in S12. The approximate plane can be obtained as a plane that minimizes the sum of the squares of the distances from the depth information, for example, by the least squares method. Then, the processor 251 corrects the inclination of the entire distance image acquired in S11 (i.e., performs coordinate conversion of the depth information) so that the distance (depth) to the approximate plane is uniform. The straight line indicated by the dashed line in FIG. 8 is the approximate plane of the face. The processor 251 stores the approximate plane of the face in the storage device 252 to use it as a reference plane in subsequent processing. FIG. 9 is a diagram showing an example of a distance image after correction. 9, the horizontal axis represents the position on the X axis, and the vertical axis represents the distance (depth). In this step, the tilt is corrected including the depth information corresponding to the inside of the blast hole 3.

[0029] Then, processor 251 removes noise (FIG. 5: S14). In this step, processor 251 removes noise from the depth information of the distance image after the tilt correction in S12. Noise can be removed by, for example, a convolution operation using a spatial filter. FIG. 10 is a diagram showing an example of a distance image after correction. In (A) in the upper part of FIG. 10, the horizontal axis represents the position on the X axis, and the vertical axis represents the magnitude of distance (depth). In this step, large irregularities are smoothed out.

[0030] Processor 251 also identifies the coordinates with the maximum depth (FIG. 5: S15). In this step, the X and Y coordinates of the position with the maximum Z coordinate are identified. For example, in FIG. 10(A), the coordinates of the position indicated by the dashed arrow are identified. The lower part of FIG. 10(B) is a schematic diagram of a distance image corresponding to the above (A). For example, it is assumed that the coordinates with the maximum depth (the provisional center coordinates of blast hole 3) are identified at the position indicated by the symbol 31.

[0031] The processor 251 detects points that are candidates for the edge of the hole (FIG. 5: S16). The edge of the hole corresponds to the inner circumference of the hole mouth 3B. In this step, the processor 251 scans the depth information from which noise has been removed in S14, and detects a candidate for the edge when the depth is greater than the reference plane by a predetermined threshold or more. FIG. 11 is a diagram for explaining the detection of the edge of the hole. The dashed ellipse is assumed to be the actual edge of the blast hole 3. The upper part (A) of FIG. 11 shows an example of scanning the depth information included in the distance image along the X-axis (row) direction. The lower part (B) of FIG. 11 shows an example of scanning the depth information included in the distance image along the Y-axis (column) direction. In both the X-axis and Y-axis cases, when one point exceeding the threshold is detected in each row or column, the scanning transitions to the scanning of the next row or column. Therefore, the scanning in the X-axis direction extracts candidate points 32 that form one of the left and right circular arcs of the blast hole 3. Similarly, scanning in the Y-axis direction extracts candidate points 32 that form one of the upper and lower circular arcs of the blasthole 3. Note that in S16, points other than the actual edge may be detected due to the influence of unevenness or noise on the face 2.

[0032] Then, the processor 251 performs clustering to identify the edge of the hole (FIG. 5: S17). The clustering can be performed using an existing method. In this step, for example, the tentative center coordinates identified in S15 are used as the starting point, and candidate points that are located within a predetermined threshold distance from the center coordinates are classified into the same cluster. In addition, candidate points that are located within a predetermined threshold distance from the candidate points classified into the cluster may be further classified into the same cluster. The threshold used in this step can be set appropriately. A circle or ellipse may be image-detected from the candidate points detected in S16, and the threshold may be set based on the diameter. FIG. 12 is a diagram showing an example of candidate points after clustering. The points classified into the cluster are points that form the edge of the blast hole 3. The tentative center coordinates 31 are not included in the cluster. This clustering can remove noise and the like.

[0033] The processor 251 also estimates the center of the blast hole 3 based on the points forming the edge (FIG. 5: S18). FIG. 13 is a diagram for explaining the estimation of the center. In this step, for example, a rectangle 33 inscribed by the points forming the edge identified in S17 is identified, and its center 34 is estimated to be the central coordinate of the blast hole 3. The processing of S18 can be said to be processing for determining the central coordinate of a circle when the identified circular arc is symmetrical in both the left-right and up-down directions.

[0034] For example, as shown in FIG. 6, when the depth camera 253 is not directly facing the blast hole 3, when the distance image is scanned in the X-axis direction, the depth changes relatively greatly before and after the edge 3C of the inner circumference of the hole mouth 3B that is close to the depth camera 253. On the other hand, the depth does not change so greatly before and after the edge 3D that is far from the depth camera 253, because the distance from the depth camera 253 to the inner circumference 3E of the blast hole 3 is measured. The same is true for the Y-axis direction of the distance image. Therefore, it is difficult to accurately detect all of the edges of the blast hole 3 from the distance image based on a threshold value. Therefore, in S16, one of the left and right arcs and one of the top and bottom arcs are detected. In S18, the position of the blast hole 3 can be detected with high accuracy by determining the center coordinates of the circle when the arc is symmetrical left and right and up and down.

[0035] The processor 251 also outputs the coordinates of the blast hole 3 determined in S18 to the control device 15 (FIG. 5: S19). In this step, a signal indicating the coordinates of the blast hole 3 is sent from the hole detection device 250 to the control device 15, for example via a predetermined interface. As described above, in S2 of FIG. 4, alignment is performed using the coordinates obtained from the hole detection device 250. The processor 151 of the control device 15 may also use the ToF sensor 270 to confirm that the blast hole 3 actually exists at the target position after alignment.

[0036] Next, in step S3 of Fig. 4, the control device 15 automatically controls the loading rod feed mechanism 80 to advance the loading rod 18 along the detonation explosive loading direction X (Fig. 1). Then, one of the parent die attachments housed in the detonation explosive supply device 70 that is to be loaded is held at the tip of the loading rod 18, and then the parent die attachment to be loaded is loaded into the back of the blast hole 3 that is to be loaded.

[0037] 4, the loading rod feed mechanism 80 is controlled to move the loading rod 81 backward, while the additional explosive supply device 83 is operated to pressure-feed additional dies (additional explosives) to the hollow passage of the loading rod 81 through the pressure hose. The additional dies pressure-feed to the hollow passage of the loading rod 81 are loaded from the tip of the loading rod 81 into the blast hole 3 to be loaded. Then, with the loading rod 81 pulled out of the blast hole 3 to be loaded, explosive loading control is performed for the next blast hole 3 to be loaded. That is, the above-mentioned steps from S2 to S4 are sequentially repeated, and explosives can be automatically loaded into all blast holes 3.

[0038] As described above, the explosives loading system S including the hole detection device 250 can improve the accuracy of automatic loading into the blast hole 3.

[0039] <Other> The above-mentioned embodiment is an example, and the present invention is not limited to the above-mentioned configuration. The hole detection process in FIG. 5 has been described as being performed by the processor 251 of the hole detection device 250, but may be performed by the processor 151 of the control device 15. The steps shown in FIG. 4 and FIG. 5 may be changed in order as long as the result is the same, or may be performed in parallel. The depth data may be converted into so-called point cloud or other three-dimensional data and then subjected to the above-mentioned processing. The depth of the distance image and the coordinate information that the control device 15 stores in association with the hole number of the blast hole may be associated with each other by appropriate coordinate conversion.

[0040] The range imaging camera is preferably a ToF type, which allows the depth data to be measured suitably even in a dark environment such as a tunnel. The explosive loading system S may further include a laser sight for the operator to visually confirm the position where the loading rod 18 is pushed in.

[0041] In addition, the hole detection process shown in the embodiment is not limited to detecting blast holes, but may also be performed to detect drilling holes when inserting reinforcing materials such as reinforcing bars in so-called reinforcing bar insertion work (rock bolt work) in tunnels or slopes.

[0042] The subject matter of the present invention also includes a computer program for executing the above-mentioned processes, and a computer-readable recording medium having the program recorded thereon. The recording medium having the program recorded thereon enables the above-mentioned processes by causing a computer to execute the program.

[0043] A computer-readable recording medium is a recording medium that stores information such as data and programs through electrical, magnetic, optical, mechanical, or chemical action and can be read by a computer. Among such recording media, those that can be removed from a computer include flexible disks, magneto-optical disks, optical disks, magnetic tapes, memory cards, etc. Furthermore, recording media that are fixed to a computer include HDDs, SSDs, ROMs, etc. [Explanation of symbols]

[0044] 1: Explosives loading device 2: Face 3: Blast hole 3B: hole mouth 10: Heavy machinery for powder loading 12: Drilling boom 13: Explosives loading boom 14: Cockpit 15: Control device 151: Processor 152: Storage device 16: Boom body 17: Guide Shell 18: Loading rod 19: Rock drilling machine 70: Detonation explosive supply device 80: Loading rod feed mechanism 81: Loading rod 83: Additional explosive supply device 200: Work vehicle 250: Hole detection device 251: Processor 252: Storage device 253: Depth camera 270:ToF sensor

Claims

1. Obtaining depth data of an object including an excavation surface and an opening of a borehole drilled in the excavation surface from a range image sensor; scanning the depth data to detect edges of the aperture; estimating center coordinates of the hole mouth based on the detected edges; The computer performs the hole detection method.

2. The scanning includes a first scan along a first direction and a second scan along a second direction orthogonal to the first direction; The center coordinates are calculated as the center when the detected edge is symmetric in the first direction and the second direction. The hole detection method according to claim 1 .

3. The inclination of the excavation surface is estimated based on the depth data after removing outliers from the depth data, and the depth data of the object is corrected; A position where the depth of the excavation surface is greater than or equal to a predetermined threshold is detected as a candidate for the edge. The hole detection method according to claim 1 .

4. This is done by clustering the edge candidates based on the position with the greatest depth and removing noise from the edge candidates. The hole detection method according to claim 3 .

5. The distance image sensor is a ToF (Time of Flight) type sensor. The hole detection method according to claim 1 .

6. The drilling hole is a blasting hole drilled on a face of a tunnel by a blasting method, holding the explosive charge with a loading rod; A step of loading an explosive-loaded body held by the loading rod into the blast hole, with the center coordinate estimated by the hole detection method according to any one of claims 1 to 5 as a target; A method of loading explosives comprising:

7. A hole detection apparatus comprising a processor for carrying out the hole detection method according to any one of claims 1 to 5.

8. A program for causing a computer to execute the hole detection method according to any one of claims 1 to 5.

Images