A three-dimensional measuring instrument and method for laser-drilled holes

Abstract

The present invention discloses a three-dimensional laser borehole measuring instrument, which includes a cylindrical housing, adjusting rods, a laser, an industrial camera, a gyroscope, and a conical mirror. A set of adjusting rods are respectively provided at the head and tail of the outer wall of the cylindrical housing. Each set of adjusting rods is composed of three adjusting rods arranged at equal intervals on the outer wall of the cylindrical housing, and the three adjusting rods in each set of adjusting rods are 120° to each other; one end of the adjusting rod is rotatably connected to the cylindrical housing; the other end is provided with a roller; each adjusting rod can be extended and shortened; a temperature sensor is provided at the head of the cylindrical housing; a laser is fixed inside the cylindrical housing and is located at the tail. The output end of the laser is connected with an optical fiber, and the optical fiber is fixed in the cylindrical housing through an optical fiber metal frame. The end of the optical fiber is arranged in a circular radial shape; an industrial camera is provided at the head inside the cylindrical housing, the conical mirror is arranged between the industrial camera and the end of the optical fiber, and the gyroscope is arranged at the tail of the cylindrical housing.

Description

Technical Field

[0001] The present invention relates to the technical field of geotechnical engineering construction, and particularly to a laser borehole three-dimensional measuring instrument and method. Background Art

[0002] During the construction of geotechnical engineering such as mines and tunnels, there are problems where the on-site construction of workers does not conform to the engineering design specifications. During the actual borehole drilling operation, due to the limitations of the workers' own construction levels and the existence of drilling errors in the equipment, the orientation and shape of the final formed holes are not precise enough. And when the construction is completed, lateral deviation correction cannot be carried out, which may lead to problems such as difficulty in controlling the stope boundary during backfill blasting in the mine stope or even the collapse of the stope. Therefore, there is an urgent need for a borehole measurement solution that can evaluate the borehole quality, improve the hole-forming quality, and ensure the borehole construction quality. It is very necessary to carry out borehole measurement work. Summary of the Invention

[0003] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a laser borehole three-dimensional measuring instrument and method. By using a laser that emits light through an optical fiber and a conical mirror refraction as the light source to illuminate the borehole wall surface, and then using an industrial camera to take pictures throughout the process to record the hole wall morphology; after capturing, the video file is converted into a sequence of dot images in digital image format frame by frame for three-dimensional reconstruction, so as to obtain a rough model of the borehole inner diameter; through the binocular stereo vision method, the entire roadway is photographed and positioned, and the position information of a single borehole is determined, thereby reconstructing the borehole distribution model in the roadway.

[0004] The purpose of the present invention is achieved through the following technical solutions:

[0005] A laser borehole three-dimensional measuring instrument includes a cylindrical housing, adjusting rods, a laser, an optical fiber metal frame, an industrial camera, a gyroscope, and a conical mirror. A section of transparent housing is provided in the middle of the cylindrical housing. Two groups of adjusting rods are respectively provided on the outer wall of the cylindrical housing, with a spacing of 40 cm between the two groups. Each group of adjusting rods consists of three adjusting rods arranged at equal intervals on the outer wall of the cylindrical housing, and the three adjusting rods within each group are mutually at an angle of 120°; one end of the adjusting rod is rotatably connected to the cylindrical housing; the other end is provided with a roller, and the roller is controlled to move by radio; each of the adjusting rods is hydraulically adjusted and can be extended and shortened; an angle sensor is installed inside each of the adjusting rods to monitor the angle between the adjusting rod and the metal shell and output a signal; the cylindrical housing has head and tail ends, with the head facing the bottom of the borehole and the tail facing the free surface; a temperature sensor is provided at the head of the cylindrical metal shell;

[0006] A laser is fixed inside the cylindrical shell at the tail. The output end of the laser is connected to an optical fiber. The inner wall of the cylindrical shell is provided with optical fiber metal frames at equal intervals. The optical fiber metal frames are used to fix the optical fiber to ensure that the optical fiber is parallel to the central axis of the cylindrical shell. The end of the optical fiber is arranged in a circular radial shape.

[0007] An industrial camera is provided at the head inside the cylindrical shell. The imaging end of the industrial camera faces the output end of the laser. The conical mirror is arranged between the industrial camera and the end of the optical fiber. The light source of the laser is conducted to the conical mirror through the optical fiber, and the conical mirror uniformly reflects the light. The cylindrical shell between the conical mirror and the industrial camera is a transparent shell, and the light passes through the transparent shell and is finally projected in a ring shape on the wall of the blast hole, thereby illuminating a circle of the blast hole wall and being recorded in real time by the industrial camera.

[0008] The gyroscope is arranged at the tail of the cylindrical shell.

[0009] Further, the rod body direction of each adjusting rod faces the head of the cylindrical shell, and the included angle adjustment range with the central axis of the cylindrical shell is 0 - 90°.

[0010] Further, the laser is composed of a power cord, a laser output end, a signal interface, and a steel base. The laser is fixedly connected to the cylindrical shell through the steel base. One end of the power cord is connected to the laser, and the other end extends out from the tail of the cylindrical shell and is connected to an external power supply.

[0011] Further, the adjusting rod is composed of a hydraulic rod. The pressure range that the hydraulic rod can withstand is 5 - 60 kg, and the total length is 50 mm.

[0012] Further, the optical fiber is a multimode optical fiber. The diameter of each glass core is 50 μm or 62.5 μm. The glass core is sequentially wrapped with a glass cladding layer and a resin coating from the inside to the outside. Each glass core at the end of the optical fiber in a circular radial shape is parallel to the central axis of the cylindrical shell.

[0013] Further, the conical angle of the conical mirror is 90°, the included angle between the mirror surface and the central axis of the cylindrical shell is 45°, and the included angle between each glass core at the end of the optical fiber in a circular radial shape and the conical mirror surface is 45°.

[0014] Further, the transparent shell is made of polypropylene and is adhesively bonded to the cylindrical shells made of metal at both ends.

[0015] A method for three-dimensional reconstruction of blast holes based on a laser blast hole three-dimensional measuring instrument includes:

[0016] (1) Place the 3D measuring instrument into the blast hole, turn on the 3D measuring instrument. After determining that the industrial camera can capture the blast hole wall surface irradiated by the aperture, move it through radio control of the roller, so that the 3D measuring instrument runs in the blast hole driven by the roller; obtain the position information of the 3D measuring instrument through the gyroscope, capture the image information of different positions in the blast hole through the industrial camera, and at this time, the angle sensor continuously obtains the rotation angle information of the hydraulic adjusting rod; after the 3D measuring instrument runs to the bottom of the blast hole, control the roller to rotate reversely through radio, so that the 3D measuring instrument returns along the original path, take out the blast hole, and complete the acquisition of the initial information of a single blast hole;

[0017] (2) Export the video image in the industrial camera, and intercept the cross-section pictures of the blast hole frame by frame in the video processing software;

[0018] (3) Number and save the blast hole end face pictures in sequence, perform image processing, adjust the contrast and sharpness to make the laser irradiation point image different from the blast hole surrounding wall surface; and convert the image information into a digital format, form a dot sequence, and establish a grid map;

[0019] (4) Corresponding to the position data obtained in the gyroscope, reconstruct the 3D model of a single blast hole according to the occurrence information of the blast hole, and loop the above process to obtain the 3D models of all blast holes on the entire cross-section; the occurrence information of the blast hole includes the strike, dip, and dip angle of the blast hole;

[0020] (5) Set up a two-camera position according to the binocular stereo vision method to capture images of the measured roadway, determine the roadway boundary and the positions of each blast hole, and calculate the coordinate information of each blast hole through the 3D geometric relationship. Continuously repeat the above process to finally form a complete blast hole distribution model in the roadway.

[0021] Compared with the prior art, the beneficial effects brought by the technical solution of the present invention are:

[0022] 1. The invented 3D measuring instrument combines a laser, an optical fiber, a conical mirror and an industrial camera together, uses an automated mechanical roller guiding device to run in the blast hole, and cooperates with gyroscope positioning, fully integrating the advantages of each device. And through the cooperation of the devices, the overall use efficiency is improved, making the processes such as instrument operation, laser pulse conduction, digital image capture, and occurrence acquisition closely combined, with a higher degree of automation and more accurate data acquisition.

[0023] 2. Compared with the traditional blast hole goniometer, the idea of reconstructing the 3D model of the blast hole is added on its basis. Its advantage lies in that it can not only effectively obtain the blast hole occurrence during the operation of the device, but also obtain complete blast hole model information, and can more intuitively and effectively detect the construction quality of the blast hole, which has an important guiding role in aspects such as evaluating the construction progress, improving the hole-forming quality, and safety assessment and monitoring.

[0024] 3. By using the binocular stereo vision method, small-scale blast holes and large-scale roadways are organically combined. The holistic idea is conducive to constructing a complete blast hole distribution model in the roadway, which is beneficial for engineering effect inspection and geological hazard prediction at the construction site, etc.

[0025] 4. For construction guidance, standard blast hole arrangement is beneficial to improving project quality (for example, smooth blasting has high requirements for blast hole arrangement). Regular blast hole layout and the quality of blast hole drilling can ensure that the roadway section meets the usage expectations, and can greatly avoid problems such as overbreak and underbreak.

[0026] 5. For engineering safety, mastering the blast hole distribution and improving the roadway blasting level are more conducive to forming a regular roadway surface, providing more beneficial construction conditions for roadway support, and improving the support quality; and regular blast hole layout can more evenly disperse the disturbance of blasting to the surrounding rock, avoiding artificially induced geological disasters.

[0027] 6. By using a three-dimensional measuring instrument and reconstruction method, tunnel excavation and rock drilling can be predictably guided. Through the accumulation of previous data, subsequent excavation and blasting work can be further guided, which has guiding significance for blasting methods, blasting parameters, explosive dosage, etc., saving costs and improving quality and efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a schematic structural diagram of the present invention.

[0029] Figure 2 is an external structural diagram of the metal shell of the present invention.

[0030] Figure 3 is a top view and side view structural diagram of the metal shell of the present invention.

[0031] Figure 4 is a schematic structural diagram of the laser.

[0032] Figure 5 is a schematic flow diagram of the blast hole three-dimensional reconstruction method of the present invention.

[0033] Figure 6a is a schematic diagram when the three-dimensional measuring instrument is specifically applied in the blast hole; Figure 6b is a simplified view of the blast hole

[0034] Figure 7 is a schematic diagram of the binocular stereo vision reconstruction method for roadway blast holes.

[0035] Figure 8 is a schematic diagram of the binocular stereo vision method for roadways.

[0036] Reference numerals: 1 - temperature sensor, 2 - adjusting rod, 3 - roller, 4 - cylindrical housing, 5 - laser, 6 - optical fiber, 7 - optical fiber metal frame, 8 - conical mirror, 9 - industrial camera, 10 - gyroscope, 501 - power cord, 502 - laser output end, 503 - signal interface, 504 - steel base. Detailed implementation manner

[0037] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0038] As Figures 1 to 4 shown, a three-dimensional measuring instrument for laser hole drilling shown in this embodiment includes a cylindrical housing 4, an adjusting rod 2, a laser 5, an optical fiber metal frame 7, an industrial camera 9, a gyroscope 10 and a conical mirror 8. The interior of the cylindrical housing 4 body in this embodiment has a square cross-sectional structure. The outer wall of the cylindrical housing 4 is composed of an arc-shaped outer wall and a rectangular outer wall arranged alternately. Two groups of adjusting rods 2 are respectively provided on the outer wall of the cylindrical housing 4. Each group of adjusting rods 2 is composed of three adjusting rods 2 arranged at equal intervals on the outer wall of the cylindrical housing. In this embodiment, the three adjusting rods 2 in each group of adjusting rods 2 are mutually at an angle of 120°; one end of the adjusting rod 2 is rotatably connected to the cylindrical housing 4; the other end is provided with a roller 3; a temperature sensor 1 is provided at the head of the cylindrical housing to realize temperature measurement.

[0039] In this embodiment, the temperature sensor uses a pt100 sensor with a size of 2 mm to monitor the temperature inside the hole in real time, providing data support for further research; in order to make the three-dimensional measuring instrument adapt to different holes on different working surfaces, the size is adjusted by setting the angle between the rod body of the adjusting rod and the three-dimensional measuring instrument. The adjusting rod 2 uses a hydraulic rod with a pressure range of 5 - 60 kg, a total length of 50 mm, and a stroke of 20 mm. To ensure the stability of the instrument, the rod body direction of each adjusting rod is inclined towards the head of the cylindrical housing, and the adjustment range of the angle with the central axis of the cylindrical housing is 0 - 90°, avoiding the situation that the instrument is blocked in the hole and cannot be pulled out due to the unevenness inside the hole, and further improving the operation efficiency of the equipment.

[0040] In geotechnical engineering, the diameter of blast holes is generally 50 mm to 150 mm. To meet the measurement requirements for different hole diameters within this range, the outer diameter of the adjusting rod 2 in this embodiment is 8 mm. The roller uses a ring-shaped rubber with an outer diameter of 7 mm and is installed on a metal hub, having high load-bearing performance, traction performance, and buffering performance. At the same time, it is also required to have high wear resistance, flexural fatigue resistance, as well as low rolling resistance and heat generation. Given that in the short-hole blasting operation method used in mine blasting and mining, the blasting hole diameter is less than 50 mm and the hole depth is less than 5 m, and in deep-hole blasting operations, the diameter of the blast holes generally does not exceed 150 mm, the diameter of the cylindrical shell 4 is set to 40 mm to ensure that the multi-scale adjusting rod can closely adhere to the hole wall after unfolding during operation, enabling the instrument to operate smoothly.

[0041] A laser 5 is fixed inside the cylindrical shell, located at the tail. The laser 5 consists of a power cord 501, a laser output end 502, a signal interface 503, and a steel base 504. The laser 5 is fixedly connected to the cylindrical shell 4 through the steel base 504 by bolts. One end of the power cord 501 is connected to the laser 5, and the other end extends out from the bottom of the cylindrical shell to connect to an external power source. A laser switch is set at the external power source to control the operation of the laser 5. The output end of the laser 5 is connected to an optical fiber 6, and the signal interface 503 is connected to an external computer device, and the laser parameters (power, action mode, wavelength, etc.) can be adjusted.

[0042] Optical fiber metal frames 7 are equidistantly arranged on the inner wall of the cylindrical shell 4. The optical fiber metal frames 7 are used to fix the optical fiber 6. The optical fiber is at the center of the device and parallel to the cylindrical shell 4. In this embodiment, the optical fiber 6 is a multi-mode optical fiber. One end is connected to the laser 5 to transmit laser pulses into the pipeline, and the other end disassembles the fiber filaments and is set in a circular radial shape. Each glass core in the circular radial shape is parallel to the central axis, and the diameter of each glass core is 50 μm or 62.5 μm. A glass cladding layer with a refractive index lower than that of the core is wrapped outside the glass core to maintain light, and there is also a resin coating layer on the glass cladding layer as a protective cladding.

[0043] The purpose of using the optical fiber is to conduct the light source of the laser to the conical mirror through the optical fiber, scatter the light source along a cross-section, illuminate the inner wall of the blast hole in a cross-section, and facilitate the industrial camera to capture images. The low-refractive-index glass cladding layer and resin coating layer at the tail of the optical fiber are peeled off, exposing the high-refractive-index glass core at the center, facing the rear conical mirror, and completing the light conduction.

[0044] Inside the cylindrical housing, there is an industrial camera 9 at the head. The imaging end of the industrial camera 9 faces the output end of the laser 5. The conical mirror 8 is arranged between the industrial camera 9 and the end of the optical fiber. In this embodiment, the apex angle of the conical mirror is 90°, and the angle between the mirror surface and the central axis is 45°. The angle between each glass core in a circular radial pattern in the optical fiber and the mirror surface of the conical mirror is 45°. The beam emitted by the laser is conducted through the optical fiber and irradiates the conical mirror at a certain angle. The conical mirror evenly reflects the light, and finally projects it in a ring shape on the wall of the blast hole, thus illuminating a circular wall surface, which is recorded by the industrial camera.

[0045] In this embodiment, a high-pixel industrial camera 9 is adopted, which is started after the operation of the measuring instrument begins, records the video image of the cross-section of the blast hole (i.e., the irradiated area of the conical mirror), obtains the image information of the cross-section, and finally exports it in the MP4 / AVI format for reconstructing the blast hole distribution model in the roadway.

[0046] The three-dimensional measuring instrument is also equipped with a gyroscope 10, which is placed at the tail of the cylindrical housing. The gyroscope is a sensor that measures the rotation angle or angular velocity of the measuring instrument during actual operation. Based on the inertial principle, the gyroscope calculates the track of the three-dimensional measuring instrument during the operation of the measuring instrument, and obtains navigation parameters such as the position and speed of the three-dimensional measuring instrument during the forward movement, so as to maintain the stability of the instrument during the operation. In the three-dimensional measuring instrument, the role of the gyroscope is to calibrate the position coordinates of the instrument, obtain the position information of the center point of the instrument at different positions, so as to calibrate the running track of the instrument in a single blast hole, and further model the blast hole through the visual reconstruction method.

[0047] Specifically, the three-dimensional reconstruction technology is to reconstruct the panoramic three-dimensional data and model of the target from complex entities or real scenes. It mainly obtains the three-dimensional image data such as lines, surfaces, volumes, and spaces of the target and conducts high-precision three-dimensional reverse modeling. Compared with the traditional single-point measurement and surveying technology, the three-dimensional reconstruction technology combines precise sensing processes and various modern means, and fully utilizes digital image processing technology to realize model establishment. See Figure 5 , the method for three-dimensional reconstruction of blast holes based on the above laser blast hole three-dimensional measuring instrument includes:

[0048] (1) Place the three-dimensional measuring instrument into the blast hole, turn on the three-dimensional measuring instrument. After determining that the industrial camera can capture the wall surface of the blast hole irradiated by the aperture, move it through radio control of the roller, so that the three-dimensional measuring instrument runs in the blast hole driven by the roller; obtain the position information of the three-dimensional measuring instrument through the gyroscope, capture the image information at different positions in the blast hole through the industrial camera, and at this time the angle sensor continuously obtains the rotation angle information of the adjusting rod; after the three-dimensional measuring instrument runs to the bottom of the blast hole, control the roller to rotate reversely through radio, so that the three-dimensional measuring instrument returns along the original path, take out the blast hole, and complete the acquisition of the initial information of a single blast hole;

[0049] (2) Export the video images in the industrial camera and capture the cross-sectional pictures of the blast holes frame by frame in the video processing software;

[0050] (3) Number and save the blast hole end-face pictures in sequence, perform image processing, adjust the contrast and sharpness to make the laser irradiation point image distinct from the surrounding wall of the blast hole; and convert the image information into a digital format to form a dot sequence and establish a grid map;

[0051] (4) Corresponding to the position data obtained from the gyroscope, according to the occurrence information of the blast holes (blast hole strike, dip, and inclination), reconstruct the three-dimensional model of a single blast hole, and loop through the above process to obtain the three-dimensional models of all blast holes on the entire cross-section;

[0052] (5) Set up a dual camera according to the binocular stereo vision method to capture images of the measured roadway, determine the roadway boundary and the positions of each blast hole, and calculate the coordinate information of each blast hole through three-dimensional geometric relationships. Continuously repeat the above process to finally form a complete blast hole distribution model in the roadway.

[0053] Steps (2) and (3) are specifically as follows:

[0054] After the three-dimensional measuring instrument completes an entire operation process, the industrial camera records the images in the blast holes during operation, saves them in the MP4 / AVI format, and uses video processing software to extract the image frames in the video and save them. The extracted images cannot be directly used for three-dimensional reconstruction. It is necessary to first convert the cross-sectional images into a digital format, that is, a dot map sequence. The digital format images are arranged by rectangular pixel points, and each point corresponds to the image information.

[0055] Step (4) is specifically as follows:

[0056] (401) Positioning of the blast hole central axis;

[0057] To obtain the three-dimensional model of the blast hole, it is necessary to obtain all the cross-sectional images and position information within a single blast hole. Fit the cross-sectional images along the position path, and then the three-dimensional model of the entire blast hole can be obtained. The information of the running axis is determined by the gyroscope according to the positioning algorithm.

[0058] (402) Establishment of the blast hole cross-sectional image;

[0059] After converting the pictures taken inside the blast hole into digital image information, it is necessary to determine the information of the structured three-dimensional geometric parameters inside the blast hole. Each rectangular pixel dot matrix on the digital image has three integer values with different chromaticities, that is, RGB values. From this, three two-dimensional full matrix piecewise integer functions can be formed.

[0060]

[0061] where: x = 1, 2…j; y = 1, 2…k; n = 1, 2, 3

[0062] See Figure 6a and Figure 6b , the number of pixels from each laser point to the center point can be obtained through digital image processing, and then the true distance can be determined according to the pre-calibrated conversion relationship. During operation, the angles of each point remain unchanged, so the spatial positions of each laser point on the gun hole can be determined. The central axis can be expressed by the following formula:

[0063]

[0064] where: (x, y, z) - center point coordinates; l nx , l ny , l nz - adjusting rod length; θ l - center point deflection angle, l x , l y , l z - change in the center point coordinates compared to the initial position

[0065] For the laser point information captured during operation, the radius information of each point can be obtained through digital image processing. By collecting the entire imaging process, the following radius function can be obtained:

[0066] r j (t), j = 1...N

[0067] where: r i (t) - radius function of each point;

[0068] N is the number of laser points. The spatial position of each laser point can be determined by the following formula:

[0069]

[0070] where: (X 0 , Y 0 , Z 0 ) - relative coordinates of the laser point; (x, y, z) - center point coordinates; l nx , l ny , l nz - adjusting rod length; r i (t) - radius function.

[0071] The spatial rotation matrix corresponding to each laser point can be expressed as:

[0072] M i = f(θ + β i , (l x , l y , lz )) (The formula is written as a rotation operation along the axis vector)

[0073] Where: M i - Spatial rotation matrix; θ - Central point deflection angle; β i - Adjusting rod deflection angle; l x , l y , l z - Adjusting rod length;

[0074] Then the three-dimensional space coordinates corresponding to the laser point can be written as:

[0075]

[0076] Where: (X i , Y i , Z i ) - Laser point coordinates; M - Spatial rotation matrix; (X 0 , Y 0 , Z 0 ) - Laser point relative coordinates

[0077] With the spatial positions of each laser point, the three-dimensional shape of the blast hole can be formed by constructing a point-line-loop-plane strategy. In this way, the spatial position of a single blast hole can be obtained. To obtain the three-dimensional blast hole layout information of the entire cross-section, the following processing is required.

[0078] (403) Three-dimensional imaging of the cross-section blast hole diagram

[0079] The implementation of the imaging process of the cross-section blast hole diagram is based on the binocular stereo vision method. The basic principle of the binocular stereo vision method is two-point positioning, similar to human eyes. To obtain the position information of each blast hole in the roadway, image capture is performed by two cameras at different positions on both sides or the same side. Based on the parallax principle, the position distribution information of the blast holes in the roadway is reconstructed, and then the blast hole layout of the entire roadway is reconstructed by combining the single blast hole model.

[0080] The basic principle of reconstructing the roadway blast holes by the binocular stereo vision method is as follows:

[0081] As Figure 7 shown, the external area is the roadway boundary, O 1 O 2 is an industrial camera, M is a point on the roadway boundary (blast hole position), N 1 N 2 is the image point of point M on the two industrial cameras. Among them, O 1 N 1 M, O 2 N 2 M are collinear. The image taken by a single camera cannot uniquely determine the position of a point in space, such as O1 N 1 Any point on the ray can be the position of M. Therefore, by using two cameras to take pictures, the positions of point M on two image points can be obtained, and then the position of point M can be determined from O 1 N 1 and O 2 N 2 The specific position of point M can be obtained by the intersection of two rays. In addition, this application is developed for the horizontally configured binocular stereo vision method, as shown in Figure 8 :

[0082] O 1 O 2 ——The projection centers of two cameras, N 1 N 2 ——The left and right images, M——The position of a single blast hole,

[0083] The focal lengths of both cameras are set to f, b is the distance between the projection centers of the two cameras, the cameras are placed at the same height, and the y coordinates are the same. Since they are in the same cross-section, the influence of the z coordinate is not considered.

[0084] By placing each point in a triangle, the following geometric relationship can be obtained:

[0085]

[0086] Where: f - the focal length of the camera; b - the distance between the projection centers of the two cameras; (x, y, z) - the coordinates of the blast hole M point; x 1 - The x-coordinate obtained by camera o 1 x 2 - The x-coordinate obtained by camera o 2

[0087] Let the visual disparity d = x 1 - x 2 From this, the coordinates of a point M on the roadway in the three-dimensional coordinate system established with two digital cameras as the reference can be obtained:

[0088]

[0089] Where: (x, y, z) - the coordinates of the blast hole M point; x 1 - The x-coordinate obtained by camera o 1 x 2 - The x-coordinate obtained by camera o 2 f - the focal length of the camera; b - the distance between the projection centers of the two cameras; d - the visual disparity

[0090] Through this calculation method, combined with the coordinate system layout, the contour of the roadway can be depicted to form a three-dimensional model. Further, the distribution characteristics of the blast holes can be determined. Combining the three-dimensional reconstruction model of the blast holes and information such as the inclination angle, a complete blast hole distribution map in the roadway can be constructed. ​

[0091] Finally, it should be noted that the above examples are only used to illustrate the calculation process of the present invention, rather than limiting it. Although the present invention has been described in detail with reference to the foregoing examples, those of ordinary skill in the art should understand that they can still modify the calculation process recorded in the foregoing examples, or make equivalent substitutions for some of the parameters. These modifications or substitutions do not cause the essence of the corresponding calculation method to deviate from the spirit and scope of the calculation method of the present invention.

[0092] The present invention is not limited to the embodiments described above. The description of the specific embodiments above is intended to describe and illustrate the technical solutions of the present invention. The above specific embodiments are merely illustrative and not restrictive. Without departing from the spirit and scope of the present invention as defined by the claims, those of ordinary skill in the art can make many specific changes in various forms under the inspiration of the present invention, and these all fall within the protection scope of the present invention.

Claims

1. A three-dimensional measuring instrument for laser-drilled holes, characterized in that, it includes a cylindrical housing, adjusting rods, a laser, a fiber-optic metal frame, an industrial camera, a gyroscope and a conical mirror. There is a section of transparent housing in the middle of the cylindrical housing. Two groups of adjusting rods are respectively arranged on the outer wall of the cylindrical housing, with a spacing of 40 cm between the two groups. Each group of adjusting rods consists of three adjusting rods equally spaced on the outer wall of the cylindrical housing, and the three adjusting rods in each group are mutually at an angle of 120°; one end of the adjusting rod is rotatably connected to the cylindrical housing; the other end is provided with a roller, and the roller moves through radio control; each of the adjusting rods is hydraulically adjusted and can be extended and shortened; an angle sensor is installed inside each of the adjusting rods to monitor the angle between the adjusting rod and the metal shell and output a signal; the cylindrical housing has a head and a tail, the head faces the bottom of the hole, and the tail faces the free surface; a temperature sensor is provided at the head of the cylindrical metal shell; a laser is fixed inside the cylindrical housing, located at the tail. The output end of the laser is connected with an optical fiber. The inner wall of the cylindrical housing is equally spaced with fiber-optic metal frames, and the fiber-optic metal frames are used to fix the optical fiber to ensure that the optical fiber is parallel to the central axis of the cylindrical housing; the end of the optical fiber is arranged in a circular radial shape; an industrial camera is provided at the head inside the cylindrical housing, and the imaging end of the industrial camera faces the output end of the laser. The conical mirror is arranged between the industrial camera and the end of the optical fiber. The light source of the laser is conducted to the conical mirror through the optical fiber, and the conical mirror evenly reflects the light; the section of the cylindrical housing from the conical mirror to the industrial camera is a transparent housing, and the light passes through the transparent housing and is finally projected on the wall of the hole in a circular shape, thereby illuminating a circle of the hole wall and being recorded in real time by the industrial camera; the gyroscope is arranged at the tail of the cylindrical housing.

2. The three-dimensional measuring instrument for laser-drilled holes according to claim 1, characterized in that, the rod body direction of each of the adjusting rods faces the head of the cylindrical housing, and the adjustment range of the angle between the adjusting rod and the central axis of the cylindrical housing is 0 - 90°.

3. The three-dimensional measuring instrument for laser-drilled holes according to claim 1, characterized in that, the laser consists of a power cord, a laser output end, a signal interface and a steel base. The laser is fixedly connected to the cylindrical housing through the steel base. One end of the power cord is connected to the laser, and the other end extends out from the tail of the cylindrical housing and is connected to an external power source.

4. The three-dimensional measuring instrument for laser-drilled holes according to claim 1 or 2, characterized in that, the adjusting rod is composed of a hydraulic rod, and the pressure range that the hydraulic rod can withstand is 5 - 60 kg, and the total length is 50 mm.

5. The three-dimensional measuring instrument for laser-drilled holes according to claim 1, characterized in that, the optical fiber is a multimode optical fiber, the diameter of each glass core is 50 μm or 62.5 μm, and a glass cladding layer and a resin coating are sequentially wrapped on the glass core from the inside to the outside. Each glass core at the end of the optical fiber in a circular radial shape is parallel to the central axis of the cylindrical housing.

6. The three-dimensional measuring instrument for laser-drilled holes according to claim 1, characterized in that, The cone angle of the conical mirror is 90°, the angle between the mirror surface and the central axis of the cylindrical housing is 45°, and the angle between each glass core at the end of the optical fiber in a circular radial shape and the mirror surface of the conical mirror is 45°.

7. The three-dimensional laser hole measuring instrument according to claim 1, characterized in that the transparent housing is made of polypropylene and is adhesively connected to the cylindrical housings made of metal at both ends.

8. A method for three-dimensional reconstruction of a blast hole based on the three-dimensional laser hole measuring instrument according to claim 1, characterized in that it includes: (1) Place the three-dimensional measuring instrument into the blast hole, turn on the three-dimensional measuring instrument. After determining that the industrial camera can capture the blast hole wall surface irradiated by the aperture, move it by radio control of the roller, so that the three-dimensional measuring instrument runs in the blast hole driven by the roller; obtain the position information of the three-dimensional measuring instrument through the gyroscope, capture the image information at different positions in the blast hole through the industrial camera, and at this time, the angle sensor continuously obtains the rotation angle information of the hydraulic adjusting rod; after the three-dimensional measuring instrument runs to the bottom of the blast hole, control the roller to rotate reversely by radio, so that the three-dimensional measuring instrument returns along the original path, take out the blast hole, and complete the acquisition of the initial information of a single blast hole; (2) Export the video image in the industrial camera, and intercept the cross-sectional pictures of the blast hole frame by frame in the video processing software; (3) Number and save the blast hole end pictures in sequence, perform image processing, adjust the contrast and sharpness to make the laser irradiation point image different from the surrounding wall surface of the blast hole; and convert the image information into a digital format to form a dot sequence and establish a grid map; (4) Corresponding to the position data obtained in the gyroscope, reconstruct the three-dimensional model of a single blast hole according to the occurrence information of the blast hole, and repeat the above process to obtain the three-dimensional models of all blast holes on the entire cross-section; the occurrence information of the blast hole includes the strike, dip, and dip angle of the blast hole; (5) Set up a double camera according to the binocular stereo vision method to capture images of the measured roadway, determine the roadway boundary and the positions of each blast hole, and calculate the coordinate information of each blast hole by inverse calculation through three-dimensional geometric relationships. Continuously repeat the above process to finally form a complete blast hole distribution model in the roadway.

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