A laser-based full-section convergence deformation monitoring system and method for mine roadways

Abstract

The present invention provides a laser-based full-section convergence deformation monitoring system and method for mine roadways, including: a laser rangefinder and its card seat, a height calibration target, a monitoring device base plate, pre-embedded support rods, pre-embedded measuring points around the roadway, a computer device, and a readable storage medium. The distances from the laser rangefinders at the bottom corners of the left and right sides of the roadway floor to the height calibration target and each pre-embedded measuring point are measured, and the coordinate values of each pre-embedded measuring point in the rectangular coordinate system of the roadway section are calculated according to the triangle side-angle relationship; the coordinate values of the pre-embedded measuring points are interpolated through a roadway section contour interpolation calculation program to obtain the roadway section contour graph, so as to obtain the single-period and multi-period convergence deformation data of the entire roadway section. Through this method, the evolution of the roadway convergence deformation during the mine mining process can be quickly monitored, providing a strong guarantee for the safe and efficient mining of the mine.

Description

Technical Field

[0001] The present invention belongs to the technical field of mining engineering roadway convergence deformation monitoring, and specifically relates to a full-section convergence deformation monitoring system and method for mine roadways based on lasers. Background Technique

[0002] The development of mineral resources is an important material basis for ensuring social stability and economic development. As the shallow mineral resources on the earth are gradually exhausted, mining activities are continuously extending deeper into the earth, bringing about a harsh mining environment with high ground stress, high temperature, high humidity, and high pressure. The surrounding rock of deep mining roadways will encounter problems such as huge deformation, and the occurrence frequency of serious mine geological disasters such as roadway roof collapse and rock bursts also increases significantly.

[0003] Therefore, quickly obtaining and revealing the full-section convergence deformation characteristics and evolution laws of mining roadways is crucial for comprehensively reflecting the stress distribution of the surrounding rock during roadway excavation and effectively revealing the deformation and failure mechanism of roadways under mining influence. It can provide a data basis for proposing scientific and reasonable surrounding rock deformation control technologies and timely and effectively controlling the ground pressure manifestation of mined roadways. Although laser scanners, total stations, etc. used in tunnel engineering can measure the full-section convergence deformation of roadways, it is necessary to set up base points at stable rock mass positions far from the stope and pass through a long lead path to finally determine the coordinate values of the measurement points in the mining roadway. On this basis, devices such as laser scanners and total stations are used to measure the convergence deformation of the roadway. The implementation of this type of measurement technology also requires the cooperation of auxiliary tools such as tripods and trays. Carrying a large number of monitoring devices to the underground operation area will bring many disadvantages such as a long transportation distance, high time cost, and poor convenience of underground operation. Moreover, it occupies the roadway space and cannot be paused during the measurement, causing long-term interference to underground mining operations. The above factors make it impossible to be widely used in the daily monitoring of mine roadway convergence deformation.

[0004] The existing methods and devices for mining roadway convergence deformation have the following disadvantages:

[0005] 1. In the roadway convergence monitoring in underground mining engineering, the cross-point layout method is mostly used. This method sets several measurement points on the surface of the roadway roof, floor, and two sides, and arranges several measurement lines between the measurement points. The convergence deformation of the roadway section is reflected by the change in the length of the measurement line. However, this method can only measure the data at the measurement point positions of the roadway and cannot monitor the full-section convergence deformation law of the roadway. The obtained roadway convergence deformation data is relatively limited, and the monitoring results obtained by this method belong to the relative deformation amount between two measurement points on the surface of the roadway surrounding rock and cannot reflect the absolute convergence deformation situation at a certain position on the roadway surface.

[0006] 2. Existing methods for setting reference points for roadway convergence deformation monitoring and their disadvantages: (1) Leading a line point by point from a known coordinate reference point far from the stope that is not affected by mining and other underground projects along the existing roadway to the reference point of the target roadway section. Considering the complex environment of underground mine roadway engineering layout, as well as difficult conditions such as poor visibility, many interferences, and uneven floors during underground work, this work will consume high labor and time costs and seriously affect the continuous operation of various underground mining processes; (2) Setting reference points on the surface of the roof, floor, and two sides. However, under the action of excavation or mining stress disturbances, obvious convergence deformation occurs on the surface of the roadway surrounding rock, causing the reference points to move, bringing large errors to multiple measurements, especially long-term measurements. Moreover, the reference points at the floor and low side positions are also easily damaged by ore truck transportation or supplementary support operations.

[0007] 3. Most of the full-section convergence deformations of existing mining roadways are obtained by linearly interpolating the deformation data of a small number of measuring points around the roadway. In fact, in order to better resist the surrounding rock deformation caused by mining stress, the roadway roof is usually set as an arch shape, which requires a non-linear interpolation method to obtain a smoother interpolation curve. In addition, for the interpolation of an arch-shaped cross-section roadway by linear interpolation, fewer measuring points will undoubtedly cause greater errors. Therefore, it is more appropriate to choose a non-linear interpolation method in the full-section convergence measurement of arch-shaped roadways. Summary of the Invention

[0008] In order to make up for the deficiencies of the existing mine roadway convergence deformation monitoring technology, the present invention provides a laser-based mine roadway full-section convergence deformation monitoring system and method, which are realized through the following technical solutions:

[0009] A laser-based mine roadway full-section convergence deformation monitoring method includes the following steps:

[0010] Step 1. Use a laser rangefinder to measure the distance L from the reference point on the left / right side of the section to the reference point on the right / left side of the section. mn , Use a laser rangefinder to measure the distances L mi and L ni from the reference points on the left and right sides of the section to each measurement point on the section contour. The reference points on the left / right side of the section are at the same height, and i is the number of each measurement point;

[0011] Step 2. Taking the midpoint of the line connecting the two reference points as the origin, use the data measured in Step 1 to calculate the dip angle β, the distance L Ji between the origin and each measurement point, and the dip angle α. The dip angle α is the angle between the line connecting the origin and each measurement point and the horizontal plane on the right side of the origin. The dip angle β is the angle between the line connecting the reference point on the left side of the section and each measurement point on the section contour and the horizontal plane on the right side of the origin, and obtain the coordinates (x ih0 , yih0 ), h0 is the initial height of the reference point;

[0012] cosβ = (L mi ² + L mn ² - L ni ²) / (2·L mi ·L mn );

[0013] L Ji ² = L mi ² + (L mn / 2)² - 2·L mi ·L mn / 2·cosβ;

[0014] cosα = [L Ji ² + (L mn / 2)² - L ni ²] / [2·L Ji ·(L mn / 2)];

[0015] x ih0 = L Ji ·sinα;

[0016] y ih0 = -L Ji ·cosα;

[0017] Step 3. Repeat Steps 1 - 2 in the next monitoring period to obtain the coordinates (x ihf , y ihf ) of each measurement point relative to the origin in this monitoring period. h f is the height of the reference point measured in the f - th monitoring period. Translate the coordinates of each measurement point relative to the origin obtained in each monitoring period to the same coordinate system:

[0018] x' i(0) = x ih0 , y' i(0) = y ih0 ;

[0019] x' i(f) = x ihf + h f - h0, y' i(f) = y ihf ;

[0020] Step 4. Divide all the measurement points into left and right regions based on the center line of the cross-section, and save the coordinate information of each measurement point in the two regions during each monitoring period. Use the spline interpolation method in Matlab to perform interpolation calculations on the coordinates of each measurement point in the two regions obtained during each monitoring period, and obtain the coordinate values of the interpolated points around the roadway in the two regions during each monitoring period. Based on the interpolation results, draw function curves in the Matlab software, and obtain the roadway cross-section contour graphics of the two regions during each monitoring period. Stitch the cross-section contours of the two regions during the same monitoring period together and present them simultaneously in the same rectangular coordinate system to obtain the convergence deformation of the entire roadway cross-section during multiple monitoring periods.

[0021] Further, step 1 includes:

[0022] S01: Symmetrically install two monitoring device bases at positions near the two sides of a cross-section of the roadway, fix multiple target plates along the cross-section contour line, and the measurement points are the centers of the target plates;

[0023] S02: Install a base with a laser rangefinder on the first monitoring device base, install a height calibration target on the second monitoring device base, adjust the base so that the laser beam emitted by the laser rangefinder is parallel to the upper surface of the monitoring device base, adjust the upper surfaces of the two monitoring device bases to the same height and horizontal position, so that the laser beam projects to the center of the height calibration target, and record the distance L between the two monitoring device bases measured by the laser rangefinder mn , and at the same time record the distance h0 between the upper surface of the first monitoring device base and the reference plane. The reference plane includes the bottom plate of the roadway and the lower surface of the monitoring device base, measure and record the distance L from the light source point of the laser rangefinder to the center point of each target plate mi ;

[0024] S03: Keep the positions of the two monitoring device bases unchanged, swap the positions of the laser rangefinder and the base with the height calibration target, and measure and record the distance L from the light source point of the laser rangefinder to the center point of each target plate ni ; where i is the number of the target plate; Step 1: Symmetrically install two monitoring device bases at positions near the two sides of a cross-section of the roadway, and fix multiple target plates along the cross-section contour line;

[0025] The reference points include the light source point of the laser rangefinder and the center of the height calibration target. When the base and the height calibration target are respectively installed on the two monitoring device bases, the center of the height calibration target and the light source point are respectively located on the central axes of the two monitoring device bases.

[0026] Further, the monitoring device base includes a top plate and a bottom plate, and there are at least three legs with adjustable heights between the top plate and the bottom plate, and all the legs are evenly arranged around the centers of the top plate and the bottom plate.

[0027] Further, the base and the height calibration target are detachably connected to the center of the top plate. The base is rotatably connected to the laser rangefinder. When the base is installed on the top plate, the laser rangefinder can rotate in a plane perpendicular to the top plate. When the height calibration target is installed on the top plate, it is perpendicular to the top plate. The distance between the center of the height calibration target and the center of the top plate is equal to the distance between the laser rangefinder and the center of the top plate from the rotation axis of the base.

[0028] Further, the height of the reference point or the initial height is replaced by the distance between the centers of the top plate and the bottom plate.

[0029] The coordinate information of each measurement point in the two regions during each monitoring period saved in Step 4 is the polar coordinates (t i(f) , y' i(f) ) converted from (x' i(f) , r i(f) ), with the origin as the pole and the vertical line above the origin as the polar axis.

[0030] In Step 4, the spline interpolation method in Matlab is used to perform interpolation calculations on the coordinates of each measurement point in the two regions obtained during each monitoring period, respectively obtaining the coordinate values of the interpolation points around the roadway in the two regions during each monitoring period. Based on the interpolation results, function curves are plotted in the Matlab software, and the roadway cross-section contour graphics of these two regions are obtained during each monitoring period. The cross-section contours of the two regions during the same monitoring period are spliced together and presented simultaneously in the same rectangular coordinate system, including:

[0031] X1. Store the polar coordinate values of the measurement points on the left half contour of the roadway cross-section in the XYK matrix. The first column of data is the polar angle component coordinate t i(f) , and the second column of data is the polar radius component coordinate r i(f) .

[0032] X2. Assign the first column of data and the second column of data in the matrix to the temporary arrays t0 and r0, respectively.

[0033] X3. Set the number of interpolation points on the left half contour of the roadway cross-section and the interpolation range of the polar angle coordinates.

[0034] X4. Calculate the polar radius coordinate component of the interpolation points on the left half contour of the roadway cross-section through cubic spline interpolation.

[0035] X5. Convert the polar coordinates of the interpolation points into rectangular coordinates.

[0036] X6. Draw the left half contour of the roadway cross-section based on the rectangular coordinates of the interpolation points.

[0037] X7. Store the polar coordinate values of the measurement points on the right half contour of the roadway cross-section in the XYL matrix. The first column of data is the polar angle component coordinate t i(f) , and the second column of data is the polar radius component coordinate r i(f);

[0038] X8. Repeat steps X2 - X6 to draw the right - hand half contour of the roadway section, thus obtaining the complete roadway section contour line.

[0039] Furthermore, a computer device, a memory, and a processor, the memory and the processor are communicatively connected to each other. The memory stores computer instructions, and the processor executes the computer instructions to perform steps 2 - 4 of the laser - based full - section convergence deformation monitoring method for mine roadways according to the monitoring data collected in each monitoring cycle, and obtain the full - section convergence deformation conditions of the mine roadway in multiple monitoring cycles.

[0040] The monitoring data includes: the distance L from the reference point on the left / right rib of the section to the reference point on the right / left rib of the section mn , the distances L from the reference points on the left and right ribs of the section to each measurement point on the section contour mi and L ni , the height h of the reference point f .

[0041] Furthermore, a computer - readable storage medium stores computer instructions thereon, and the computer instructions are used to cause a computer to perform steps 2 - 4 of the laser - based full - section convergence deformation monitoring method for mine roadways according to the monitoring data collected in each monitoring cycle, and obtain the full - section convergence deformation conditions of the mine roadway in multiple monitoring cycles.

[0042] The monitoring data includes: the distance L from the reference point on the left / right rib of the section to the reference point on the right / left rib of the section mn , the distances L from the reference points on the left and right ribs of the section to each measurement point on the section contour mi and L ni , the height h of the reference point f .

[0043] The present invention has the following advantages and positive effects:

[0044] (1) It can reflect the full - section convergence deformation of mine roadways. Compared with the existing roadway convergence monitoring that mainly measures indexes such as roof subsidence, floor heave, and rib approach, the mine roadway convergence deformation monitoring method and device proposed in the present invention can obtain the single - time convergence deformation and cumulative convergence deformation at each position of the roadway section.

[0045] (2) High stability and accuracy. First, in this invention, the embedded support rod passes through the relatively soft surface rock mass of the roadway floor and is embedded at a certain depth inside the relatively stable bedrock, ensuring that the embedded support rod and the devices above it will not move with the deformation of the floor surface. In addition, a metal protection box is set at the upper end of the embedded support rod, and both the support rod and the protection box are buried underground. The protection box will only be opened and the monitoring device will be installed at the upper end of the support rod when roadway monitoring is carried out. This setting can effectively protect the support rod and avoid damage to the support rod during operations such as underground roadway support and the driving of mining and transportation vehicles. In the prior art, the reference points set on the surface of the roadway section are subject to stress interference during mining, which will cause the reference points to shift and are easily damaged by mining activities. Reintroducing points from a stable area far from the stope will consume a large amount of manpower and material resources.

[0046] Second, since the embedded support rod is fixed at a certain depth in the floor bedrock and does not move relatively with the floor heave deformation, during each measurement, the base plate of the monitoring device is installed at the designated position of the support rod. After leveling the laser rangefinder, the height calibration target on the base plate of another monitoring device is adjusted to the same height, ensuring that the three points of the light source point of the laser rangefinder, the center point of the height calibration target, and the embedded measurement point form a triangle with a horizontal base. Thus, according to the relationship between the sides and angles of the triangle, the coordinate value of the embedded measurement point can be calculated smoothly. Then, during each subsequent monitoring, the average value of the distance between the upper and lower discs at the position of the triangular spiral first wheel in the base plate of the monitoring device is used to correct the coordinates of the embedded measurement point, ensuring the unity of the coordinates of the embedded measurement points calculated in each monitoring period.

[0047] Third, the back of the base is connected to the vertical plate of the L-shaped steel plate by bolts, and the horizontal plate of the L-shaped steel plate is connected to the top of the base plate of the monitoring device by bolts, and the axes of the horizontal plate bolts and the vertical plate bolts intersect at the light source point of the laser rangefinder, ensuring that when adjusting the ray angle of the laser rangefinder, the position of its light source point remains unchanged. The height calibration target can be fixed to the top of the base plate of the monitoring device by bolts, and the height from the light source point of the laser rangefinder to the top surface of the base plate of the monitoring device is equal to the height from the center point of the height calibration target to the top surface of the base plate of the monitoring device, ensuring that when using the laser rangefinder to replace the height calibration target to measure the embedded measurement point, the position of the target center and the light source point of the laser rangefinder always coincide.

[0048] Finally, this invention uses a relatively small number of embedded measurement points around the roadway for roadway convergence deformation monitoring, causing less disturbance to the surrounding rock of the roadway surface. Considering the influence of a small number of measurement points on the interpolation accuracy, this invention provides a convenient calculation and processing method for drawing a more accurate cross-sectional shape of the mine roadway based on the coordinates of a small number of embedded measurement points around the roadway. The spline interpolation method is used to interpolate the coordinates of the embedded measurement points, while the linear interpolation method is mostly used in the existing mining roadway cross-sectional measurement technology. The cross-sectional shape of the roadway drawn accordingly has poor accuracy in the arched section.

[0049] (3) Other technical advantages of the present invention: The monitoring device is small in size and light in weight, and can be carried around. The monitoring method is simple to operate and takes a short time, greatly improving the convenience and reducing the impact on the on-site production of the mine; the monitoring results are the true coordinates of the measuring points on the surface of the roadway section. Based on this, the absolute displacement size and direction of the measuring points can be calculated. The traditional mine roadway convergence monitoring method usually obtains the relative displacement of two points along the connecting line. Compared with this, the present invention can clarify the actual convergence deformation of each point on the roadway surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 It is the layout diagram of the embedded support rods of the present invention;

[0051] Figure 2 It is the structural schematic diagram of the monitoring device of the present invention;

[0052] Figure 3 It is the structural schematic of the embedded support rod of the present invention Figure 1 ;

[0053] Figure 4 It is the structural schematic of the embedded support rod of the present invention Figure 2 ;

[0054] Figure 5 It is the front structural schematic diagram of the card seat after the laser rangefinder is installed in the present invention;

[0055] Figure 6 It is the back structural schematic diagram of the card seat after the laser rangefinder is installed in the present invention;

[0056] Figure 7 It is the structural schematic diagram of the base plate of the monitoring device in the present invention;

[0057] Figure 8 It is the lower structural schematic diagram of the top plate of the base plate of the monitoring device in the present invention;

[0058] Figure 9 It is the structural schematic diagram of the height calibration target in the present invention;

[0059] Figure 10 It is the structural schematic diagram of the embedded measuring points around the roadway in the present invention;

[0060] Figure 11 It is the schematic diagram of the coordinate positioning principle of the embedded measuring points around the roadway in the present invention;

[0061] Figure 12 It is the interpolation calculation program of the roadway section contour in the present invention;

[0062] Figure 13 It is the evolution diagram of the convergence deformation of the roadway section contour in the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0063] To make the objectives, technical solutions, and advantages of the embodiments of the present disclosure clearer, the technical solutions of the embodiments of the present disclosure will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the described embodiments of the present disclosure without creative efforts shall fall within the scope of protection of the present disclosure.

[0064] It should be noted that the term "roadway" as used herein refers to a passage dug underground for mineral extraction.

[0065] The "left rib" refers to the left wall surface or rock surface when facing the extending direction of the roadway upon entering the roadway. Correspondingly, the right wall surface or rock surface facing the extending direction of the roadway is called the "right rib".

[0066] The "full cross-section of the roadway" refers to the entire cross-section perpendicular to the center line of the roadway.

[0067] Embodiment 1:

[0068] As Figures 1 to 11 shown, in this embodiment, a laser-based full cross-section convergence deformation monitoring system for a mine roadway is provided, including: a first pre-embedded support rod 1, a second pre-embedded support rod 10, a monitoring device base plate 6, a laser rangefinder 7, a base 8, a height calibration target 9, a target plate 27, and a roadway cross-section contour interpolation calculation program.

[0069] As Figure 1 、 Figure 3 、 Figure 4 shown, drill holes are symmetrically arranged near the left rib and the right rib and perpendicular to the ground at a cross-section in the roadway. Measuring points are evenly arranged on the roadway contour line of this cross-section. A target plate 27 is pre-embedded in each measuring point. The upper part of the drill hole is reamed, and the first pre-embedded support rod 1 and the second pre-embedded support rod 10 are inserted into the drill holes. Circular metal protection boxes 2 are welded to the upper ends of the first pre-embedded support rod 1 and the second pre-embedded support rod 10, so that the metal protection boxes 2 can just be placed inside the reamed holes with matching sizes. The upper end of the metal protection box 2 is provided with a rotatable round cover 3. In addition, the first pre-embedded support rod 1 is provided with a horizontal metal positioning plate 4 near the upper end position.

[0070] As Figure 5 、 Figure 6As shown in the figure, the base 8 is a section of short channel steel that has been cut. The inner side wall of the channel steel is provided with a positioning plate 11. The contour of the laser rangefinder 7 matches the side dimensions of the base 8. The light source end of the laser rangefinder 7 faces the positioning plate 11 and is tightly installed inside the base 8, ensuring that the light source end face of the laser rangefinder 7 is closely attached to the positioning plate 11. The outer side wall of the base 8 is provided with a leveling bubble 12; the back of the base 8 is connected to the vertical plate 14 of the L-shaped steel plate through bolt 13. After bolt 13 is loosened, the base 8 can rotate relative to the vertical plate 14 around bolt 13. The bottom horizontal plate 15 of the vertical plate 14 is connected to the top of the monitoring device base plate 6 through bolt 16, and the axes of bolt 16 and bolt 13 intersect at the light source point 17 of the laser rangefinder; after the laser rangefinder 7 is fixed to the base 8, it is installed on the top of the monitoring device base plate 6 through threaded connection. The height calibration target 18 is fixed to the top of another monitoring device base plate 6 through threaded connection, so that the height calibration target 18 and the laser rangefinder 7 are arranged opposite to each other and the light emitted by the laser rangefinder is perpendicular to the surface of the height calibration target; in order to make the positions of the light source point 17 and the center position of the height calibration target 19 coincide after the laser rangefinder 7 and the base 8 are replaced with the height calibration target 18, the height from the center of the height calibration target 19 to the top surface of the monitoring device base plate 6 is the same as the height from the light source point 17 of the laser rangefinder to the top surface of the monitoring device base plate 6, and the center of the height calibration target 19 and the light source point 17 of the laser rangefinder are both located on the extension line of the central axis of the top surface of the monitoring device base plate 6.

[0071] As Figure 7 shown, the monitoring device base plate 6 is provided with two metal discs, a top disc 20 and a bottom disc 21. The center of the top surface of the top disc is provided with a threaded round hole 22. The bottom surface of the top disc is symmetrically centered on the center of the disc surface, and three round holes 23 are evenly arranged perpendicular to the disc surface and are distributed in an equilateral triangle ( Figure 8 ), and the top surface of the bottom disc is symmetrically centered on the center of the disc surface, and three cylindrical legs 24 are evenly arranged perpendicular to the disc surface and are also distributed in an equilateral triangle. The legs and the round holes 23 correspond to each other up and down. The legs 24 are threadedly sleeved with matching leveling angle screw handwheels 25. The upper threaded end of the leveling angle screw handwheel 25 is a quick-insert male head, which is butt-connected to the three round holes 23 on the bottom surface of the top disc; the center position of the bottom end surface of the bottom disc is provided with a threaded round tube 26, which can be threadedly connected to the upper threaded male head of the first embedded support rod 1 or the second embedded support rod 10.

[0072] As Figure 9 shown, the measurement point 5 is anchored to the bolt 28 on one side of the target disc 27.

[0073] When using the mine roadway full-section convergence deformation monitoring system described in this embodiment, the specific operation process is as follows:

[0074] Step 1: Vertically drill two circular holes downward at positions near the bottom corners of the left and right sides of the roadway floor. The distance between the hole openings and the surface of the roadway side is less than 20 cm, and the bottom of the holes penetrates more than 30 cm into the bedrock of the floor. After the holes are formed, ream the holes at the hole openings, and the reaming size matches the upper metal protection box 2 of the embedded support rod. Pour cement mortar into the holes from bottom to top, embed the first embedded support rod 1 into the hole at the left bottom corner, and embed the second embedded support rod 10 into the hole at the right bottom corner, and ensure that the first embedded support rod 1 and the second embedded support rod 10 are reliably fixed to the floor bedrock layer, and the metal protection box 2 is exactly placed in the reamed hole.

[0075] Step 2: Open the protection box of the first embedded support rod at the left bottom corner of the roadway, align the threaded round tube 26 at the bottom end face of the chassis of the monitoring device base plate 6 with the upper end of the first embedded support rod 1, and continue to connect the chassis of the monitoring device base plate 6 to the position of the horizontal metal positioning plate 4 at the upper end of the first embedded support rod 1. Connect the round hole 23 at the bottom end face of the top plate of the monitoring device base plate 6 to the three-foot screw handwheel 25 of the chassis.

[0076] Step 3: Open the protection box 2 of the second embedded support rod at the right bottom corner of the roadway, align the threaded round tube 26 at the bottom end face of the chassis of another monitoring device base plate 6 with the upper end of the second embedded support rod 10, and continue to connect the chassis of the monitoring device base plate 6 to the upper end of the second embedded support rod 10. Connect the round hole 23 at the bottom end face of the top plate of the monitoring device base plate 6 to the three-foot screw handwheel 25 of the chassis.

[0077] Step 4: Install and fix the base 8 of the laser rangefinder 7 and the height calibration target 9 on the two monitoring device base plates 6 at the left and right bottom corners of the roadway respectively. Adjust the height of the height calibration target 9 by rotating the monitoring device base plate 6 at the right bottom corner so that the height of the center 19 of the height calibration target is visually consistent with the height of the light source point 17 of the laser rangefinder. Adjust the horizontal and vertical angles of the ray of the laser rangefinder 7 so that it just shoots at the center 19 of the height calibration target at the right bottom corner, and tighten the L-shaped steel plate bolts 13 and 16 to fix the laser rangefinder 7. Level the bubble 12 on the outer side wall of the base 8 through the three-foot screw handwheel 25 of the monitoring device base plate 6 to ensure that the laser rangefinder 7 emits a horizontal light ray. At this time, if the laser ray deviates from the center 19 of the height calibration target, it can be corrected by adjusting the height of the base 6 at the right bottom corner. Read the distance L between the two monitoring device base plates at this time. mn , measure the distances a, b, c between the upper and lower plates at the position of the three-way screw first wheel 25 in the monitoring device base plate 6 at the left bottom corner. The vertical distance between the center points of the upper and lower plates is (a + b + c) / 3, that is, h0 is the initial height of the light source point 17.

[0078] Step 5: Loosen bolt 13 in the L-shaped steel plate, rotate the laser rangefinder 7 in the vertical plane to sequentially align with the center of the target plate 27 at the measurement points around the roadway, and measure and record the distance L from the light source point 17 of the laser rangefinder to the center of each measurement point target plate 27 mi ; Keep the position of the base plate 6 of the right bottom corner monitoring device unchanged, install the laser rangefinder 7 and the base 8 on the base plate 6 of the right bottom corner monitoring device, and measure and record the distance L from the light source point 17 of the laser rangefinder to the center of each measurement point target plate 27 ni ; Where i is the number of the embedded measurement points around the roadway (i = 1, 2, 3…).

[0079] Step 6: Connect the light source point 17 of the left bottom corner laser rangefinder to the center 19 of the height calibration target, set the midpoint of the connection line as the origin, establish a local coordinate system, with the positive direction of the x-axis vertically upward along the connection line, and the positive direction of the y-axis from the origin to the light source point 17 of the left bottom corner laser rangefinder; Calculate the inclination angle β, the distance L from the origin to the connection line of the i-th measurement point 5, the inclination angle α according to the triangle side-angle relationship Ji ; The inclination angle α is the angle between the connection line of the origin and each measurement point and the horizontal plane on the right side of the origin, and the inclination angle β is the angle between the connection line of the light source point 17 of the left bottom corner laser rangefinder and the center of each measurement point target plate 27 and the horizontal plane on the right side of the origin. Through the distance L from the reference point to the connection line of the i-th measurement point 5 Ji and the inclination angle α, the local coordinate value (x ih0 , y ih0 ) of the i-th measurement point 5 can be calculated;

[0080] cosβ = (L mi ² + L mn ² - L ni ²) / (2·L mi ·L mn );

[0081] L Ji ² = L mi ² + (L mn / 2)² - 2·L mi ·L mn / 2·cosβ;

[0082] cosα = [L Ji ² + (L mn / 2)² - L ni ²] / [2·L Ji ·(L mn / 2)];

[0083] x ih0 = L Ji ·sinα;

[0084] y ih0 = -LJi ·cosα;

[0085] Step 7: Repeat Steps 2 - 6 in the next monitoring period, regularly monitor the coordinate values of the measurement point 5, and obtain the local rectangular coordinate values (x ihf , y ihf ) of each measurement point 5 in this monitoring period. Taking the local coordinate system established in the first monitoring period as the global coordinate system, the global coordinate values of each measurement point 5 in the first monitoring period are x' i(0) = x ih0 , y' i(0) = y ih0 ; The coordinate data of the measurement point 5 obtained in the next monitoring period needs to be converted through the following formula: x' i(1) = x ih1 + (a(1) + b(1) + c(1)) / 3 - (a(0) + b(0) + c(0)) / 3, y' i(1) = y ih1 ; After measurements in multiple periods, the global coordinate values x' i(f) = x ihf + (a(f) + b(f) + c(f)) / 3 - (a(0) + b(0) + c(0)) / 3, y' i(f) = y ihf of each measurement point 5 in multiple periods can be obtained, where f is the f - th monitoring period.

[0086] Step 8: Based on the center line of the roadway section, divide all the pre - embedded measurement points 5 around the roadway into two measurement point sets, the left and the right, and make the measurement point 5 at the center of the roadway section arch top be in both measurement point sets at the same time. Taking the origin of the global rectangular coordinate system as the pole and the positive half - axis of the x - axis as the polar axis, convert the rectangular coordinates (x' i(f) , y' i(f) ) of the two measurement point sets into polar coordinates (t i(f) , r i(f) ), and save them in two Excel - format files respectively.

[0087] Step 9: Read the above two Excel - format files through the import data option in matlab, and store them in the matlab workspace in the form of matrices, named XYK and XYL respectively. Based on the cubic spline interpolation method in the matlab software, use as Figure 12The interpolation calculation program for the roadway section profile shown calculates the coordinates of the interpolation points on the left and right sides of the roadway section centerline in the global rectangular coordinate system according to XYK and XYL respectively, and uses the plot command in the matlab software to draw the function curves corresponding to the left and right sides of the roadway section centerline, so as to obtain the roadway section profile graphics of the left and right regions respectively. By splicing the roadway section profiles of the left and right regions with the coordinate origin (0, 0) as the base point, the roadway full-section profile after convergence deformation can be visually displayed:

[0088] fx>>t0 = XYK(:,1); Assign the first column data (polar angle component t i(f) ) of XYK to the one-dimensional array t0;

[0089] t1 = linspace(1.6987, 0.0070, 18); Set 18 interpolation points at equal intervals along the left half contour of the roadway section. The polar angle interpolation range is (1.6987, 0.0070), and assign the polar angle component of the interpolation points to the one-dimensional array t1. 0.0070~1.6987 represents 0°~97° in radians;

[0090] r0 = XYK(:,2); Assign the second column data (polar radius component r i(f) ) of XYK to the one-dimensional array r0;

[0091] r1 = interp1(t0,r0,t1,'spline'); Among them, the r1 = interp1(t0,r0,t1,'spline') command inputs the coordinates of the point set XYK and the values of the corresponding known data points, as well as the position t1 of the new coordinate points for which interpolation calculation is to be performed, and performs cubic spline interpolation;

[0092] x1 = r1.*cos(t1); Calculate the x component of the interpolation points in the rectangular coordinates and assign it to the one-dimensional array x1;

[0093] y1 = r1.*sin(t1); Calculate the y component of the interpolation points in the rectangular coordinates and assign it to the one-dimensional array y1;

[0094] plot(x1,y1,'r'); Draw the left half contour curve of the roadway section with a red line,

[0095] hold on

[0096] t0 = XYL(:,1); Assign the first column data (polar angle component t i(f) ) of XYL to the one-dimensional array t0;

[0097] t2 = linspace(-1.7019, 0.0070, 18); Set 18 interpolation points along the right - hand contour of the roadway section, and assign its polar - angle components to the one - dimensional array t2;

[0098] r0 = XYL(:,2); Assign the second - column data of XYL (the polar - radius component r i(f) ) to the one - dimensional array r0;

[0099] r2 = interp1(t0, r0, t2,'spline'); Calculate the polar - radius components of the interpolation points through cubic - spline interpolation and assign them to the one - dimensional array r2;

[0100] x2 = r2.*cos(t2); Calculate the x - component of the interpolation points in Cartesian coordinates and assign it to the one - dimensional array x2;

[0101] y2 = r2.*sin(t2); Calculate the y - component of the interpolation points in Cartesian coordinates and assign it to the one - dimensional array y2;

[0102] plot(x2, y2, 'r'); Plot the right - hand contour curve of the roadway section with a red line,

[0103] xlabel('Lane height'); The x - axis represents 'Lane height';

[0104] ylabel('Lane width'); The y - axis represents 'Lane width';

[0105] axis equal; Display the two axes in equal proportion;

[0106] ylim([-170, 170]); The y - axis coordinate range is [-170, 170], with the unit of cm;

[0107] xlim([-50, 300]); The x - axis coordinate range is [-50, 300], with the unit of cm;

[0108] Among them, use the hold on command to retain the plot of the XYK point set in the current coordinate area, so that the plots newly added to the coordinate area will not delete the existing plots. Perform the same operation on the point set XYL, respectively obtain the roadway - section contour graphs of these two areas in each monitoring period, splice the section contours of the two areas in the same monitoring period together, and present them simultaneously in the same Cartesian coordinate system. Use the xlabel and ylabel functions to label the names of the horizontal and vertical coordinates to obtain the convergence and deformation conditions of the entire roadway section in multiple monitoring periods.

[0109] Step 10: After the end of each monitoring period, repeat Steps 8-9, regularly draw the full-section contour of the roadway after convergence deformation, stack the full-section contours of the roadway in each period with the coordinate origin (0, 0) as the base point, and present them in the same rectangular coordinate system at the same time, then the convergence deformation of the full-section of the roadway in multiple monitoring periods can be presented, as Figure 13 shown.

[0110] In the specific embodiments described above, the technical problems solved by the present invention, the technical solutions and the beneficial effects are further described in detail. It should be understood that the above are only specific embodiments of the present invention and are not used to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A laser-based full-section convergence deformation monitoring method for mine roadways, characterized in that It includes the following steps: Step 1. Vertically drill two circular holes downward at positions near the bottom corners of the left and right sides of the roadway floor. The distance between the hole openings and the surface of the roadway side is less than 20 cm, and the bottom of the holes penetrates more than 30 cm into the bedrock of the floor. After the holes are formed, ream the hole openings, and the reaming size matches the upper metal protection box (2) of the embedded support rod. Pour cement mortar into the holes from bottom to top, embed the first embedded support rod (1) into the hole at the left bottom corner of the roadway side, and embed the second embedded support rod (10) into the hole at the right bottom corner of the roadway side, and ensure that the first embedded support rod (1) and the second embedded support rod (10) are reliably fixed to the bedrock layer of the floor, and the metal protection box (2) is exactly placed in the reamed hole; Fix a plurality of target disks (27) along the cross-section contour line, and the measurement points are the centers of the target disks (27); Step 2: Open the protection box of the first embedded support rod at the left bottom corner of the roadway side, align the threaded round tube (26) at the bottom end face of the chassis of the monitoring device base plate (6) with the upper end of the first embedded support rod (1), and continue to connect the chassis of the monitoring device base plate (6) to the position of the transverse metal positioning plate (4) at the upper end of the first embedded support rod (1). Connect the round hole (23) at the bottom end face of the top plate of the monitoring device base plate (6) to the three-legged screw handwheel (25) of the chassis; Open the protection box (2) of the second embedded support rod at the right bottom corner of the roadway side, align the threaded round tube (26) at the bottom end face of the chassis of another monitoring device base plate (6) with the upper end of the second embedded support rod (10), and continue to connect the chassis of the monitoring device base plate (6) to the upper end of the second embedded support rod (10). Connect the round hole (23) at the bottom end face of the top plate of the monitoring device base plate (6) to the three-legged screw handwheel (25) of the chassis, and install and fix the base (8) of the laser rangefinder (7) and the height calibration target (9) on the two monitoring device base plates (6) at the bottom corners of the left and right roadway sides respectively; Step 3: Adjust the height of the calibration target (9) by rotating the base plate (6) of the right heel corner monitoring device so that the height of the center (19) of the calibration target is visually the same as the height of the light source point (17) of the laser rangefinder; adjust the horizontal and vertical angles of the ray of the laser rangefinder (7) so that it just hits the center (19) of the calibration target at the right heel corner, and fix the laser rangefinder (7); level the bubble (12) on the outer side wall of the base (8) through the legs (24) of the monitoring device base plate (6) to ensure that the laser rangefinder (7) emits a horizontal light ray; at this time, if the laser ray deviates from the center (19) of the calibration target, it can be corrected by adjusting the height of the right heel corner base (6); read out the distance L between the two monitoring device base plates at this time mn , measure the distances a, b, c between the upper and lower plates at the position of the leg (24) in the left heel corner monitoring device base plate (6), and the vertical distance between the center points of the upper and lower plates is (a + b + c) / 3, that is, h0 is the initial height of the light source point (17); Step 4: Rotate the laser rangefinder (7) in the vertical plane to align it with the center of the target plate (27) of the roadway perimeter measurement point in sequence, and measure and record the distance L from the light source point (17) of the laser rangefinder to the center of each target plate (27) of the measurement point mi ; Keep the position of the base plate (6) of the right side bottom corner monitoring device unchanged, install the laser rangefinder (7) and the base (8) on the base plate (6) of the right side bottom corner monitoring device, and measure and record the distance L from the light source point (17) of the laser rangefinder to the center of each target plate (27) of the measurement point ni ; where i is the number of the pre-embedded measurement points on the roadway perimeter (i = 1, 2, 3...); Step 5. Taking the midpoint of the line connecting the light source point (17) of the laser rangefinder and the center (19) of the height calibration target as the origin, use the data measured in Steps 1 to 4 to calculate the inclination angle two β and the distance L between the origin and each measurement point Ji and the inclination angle one α. The inclination angle one α is the angle between the line connecting the origin and each measurement point and the horizontal plane on the right side of the origin. The inclination angle two β is the angle between the line connecting the left rib reference point of the cross-section and each measurement point on the cross-section contour and the horizontal plane on the right side of the origin, and obtain the coordinates (x ih0 , y ih0 ) of each measurement point relative to the origin. h0 is the initial height of the reference point; cosβ=(L mi ²+L mn ²-L ni ²) / (2*L mi *L mn ); L Ji ² = L mi ²+(L mn / 2)² - 2*L mi *L mn / 2*cosβ; cosα = [L Ji ² + (L mn / 2)² - L ni ²] / [2 * L Ji * (L mn / 2)]; x ih0 =L Ji *sinα; y ih0 = -L Ji *cosα; Step 6. Repeat Steps 3 - 5 in the next monitoring period to obtain the coordinates (x ihf , y ihf ) of each measurement point relative to the origin in this monitoring period, where h f is the height of the reference point measured in the f-th monitoring period, and translate the coordinates of each measurement point relative to the origin obtained in each monitoring period to the same coordinate system: x' i(0) =x ih0 , y' i(0) =y ih0 ; x' i(f) = x ihf + h f - h0, y' i(f) = y ihf ; Step 7. Based on the center line of the cross-section, divide all the measurement points into left and right regions, save the coordinate information of each measurement point in the two regions during each monitoring period respectively, use the spline interpolation method in matlab to perform interpolation calculations on the coordinates of each measurement point in the two regions obtained during each monitoring period respectively, obtain the coordinate values of the interpolation points around the roadway in the two regions during each monitoring period respectively, draw function curves in the matlab software based on the interpolation results, obtain the roadway cross-section contour graphics of the two regions during each monitoring period respectively, splice the cross-section contours of the two regions during the same monitoring period together, and present them in the same rectangular coordinate system at the same time to obtain the convergence deformation conditions of the entire cross-section of the roadway during multiple monitoring periods; The base plate (6) of the monitoring device is provided with a top plate (20) and a bottom plate (21). The center of the top surface of the top plate is provided with a threaded round hole (22). Taking the center of the disk surface of the top plate as the center of symmetry, three round holes (23) are evenly arranged perpendicular to the disk surface on the bottom surface of the top plate, and they are distributed in an equilateral triangle. Taking the center of the disk surface of the bottom plate as the center of symmetry, three cylindrical legs (24) are evenly arranged perpendicular to the disk surface on the top surface of the bottom plate, also distributed in an equilateral triangle. The legs correspond to the round holes (23) one by one up and down. The legs (24) are threadedly sleeved with matching leveling angle screw handwheels (25). The upper threaded end of the leveling angle screw handwheel (25) is a quick-insert male head, which is butt-connected to the three round holes (23) on the bottom surface of the top plate. A threaded round pipe (26) is provided at the center position of the bottom end surface of the bottom plate. The base (8) and the height calibration target (9) are detachably connected to the center of the top plate (20). The base (8) is rotationally connected to the laser rangefinder (7). When the base (8) is installed on the top plate (20), the laser rangefinder (7) can rotate in a plane perpendicular to the top plate (20). When the height calibration target (9) is installed on the top plate (20), the surface of the height calibration target (9) is perpendicular to the top plate (20). The distance from the center of the height calibration target (9) to the center of the top plate (20) is equal to the distance from the rotation axis of the laser rangefinder (7) and the base (8) to the center of the top plate (20). The light source point (17) is located at the intersection of the extension line of the rotation axis of the laser rangefinder (7) and the base (8) and the central axis of the monitoring device base plate (6).

2. The method according to claim 1, characterized in that, The coordinate information of each measurement point in the two regions during each monitoring period separately saved in step 7 is the polar coordinates (t i(f) , y' i(f) ) converted from (x' i(f) , r i(f) ) with the origin as the pole and the vertical line above the origin as the polar axis; In step 8, the spline interpolation method in matlab is used to perform interpolation calculations on the coordinates of each measurement point in the two regions obtained in each monitoring period, respectively obtaining the coordinate values of the interpolation points on the roadway perimeter in the two regions within each monitoring period. Based on the interpolation results, function curves are drawn in the matlab software, respectively obtaining the roadway cross-section contour graphics of these two regions in each monitoring period. The cross-section contours of the two regions in the same monitoring period are spliced together and presented simultaneously in the same rectangular coordinate system, including: X1. Store the polar coordinate values of the measurement points on the left half contour of the roadway section in the XYK matrix. The data in the first column are the coordinate values t of the polar angle component i(f) , and the data in the second column are the coordinate values r of the polar radius component i(f) ; X2. Assign the data in the first column and the second column of the matrix to the temporary arrays t0 and r0 respectively. X3. Set the number of interpolation points on the left half contour of the roadway cross-section and the interpolation range of the polar angle coordinates. X4. Calculate the polar radius coordinate components of the interpolation points on the left half contour of the roadway cross-section through cubic spline interpolation. X5. Convert the polar coordinates of the interpolation points into rectangular coordinates. X6. Draw the left half contour of the roadway cross-section according to the rectangular coordinates of the interpolation points. X7. Store the polar coordinate values of the measurement points on the right half contour of the roadway section in the XYL matrix. The data in the first column is the polar angle component coordinate t i(f) , and the data in the second column is the polar radius component coordinate r i(f) ; X8. Repeat steps X2~X6 to draw the right half contour of the roadway cross-section, thereby obtaining the complete roadway cross-section contour line.

3. A computer device, characterized in that, Including: A memory and a processor, which are communicatively connected to each other. The memory stores computer instructions. The processor executes the computer instructions to perform steps 3~7 of the laser-based full cross-section convergence deformation monitoring method for mine roadways described in claim 1 according to the monitoring data collected in each monitoring period, and obtains the roadway full cross-section convergence deformation conditions in multiple monitoring periods. The monitoring data includes: the distance L from the reference point on the left / right rib of the section to the reference point on the right / left rib of the section mn , the distances L from the reference points on the left and right ribs of the section to each measurement point on the section contour mi and L ni , the height h of the reference point f .

4. A computer-readable storage medium, characterized in that, Computer instructions are stored on the computer-readable storage medium, and the computer instructions are used to cause the computer to execute steps 3 to 7 of the laser-based full-section convergence deformation monitoring method for mine roadways described in claim 1 according to the monitoring data collected in each monitoring period, so as to obtain the full-section convergence deformation conditions of the roadway within multiple monitoring periods; the monitoring data includes: the distance L from the reference point on the left / right side of the section to the reference point on the right / left side of the section mn , the distances L from the reference points on the left and right sides of the section to each measurement point on the section contour mi and L ni , the height h of the reference point f .

Images