A single-knife material taking flow calculation method and system for a bucket wheel reclaimer

Abstract

The present invention provides a method and system for calculating the single-knife feeding flow rate of a bucket-wheel reclaimer. The present invention includes dividing the coal yard into grids; determining the coordinates of the laser scanner in the coal-yard coordinate system through the travel and attitude adjustment of the bucket-wheel machine; the bucket-wheel machine is equipped with a laser scanner to perform a full-field scan of the coal yard; triangulating the scan data after the full-field scan of the scanner with the preset points of the grid-divided coal yard, and assigning heights to all preset points in the triangulated coal yard; calculating the volume of the triangular prism to obtain the total volume of the coal-yard stockpile, and obtaining the coal storage information of the coal yard; obtaining the three-dimensional position coordinates of the characteristic points on the bucket wheel in the coal yard, and traversing whether the preset points in the coal yard are within the newly built triangular grid; after the single-knife feeding is completed, the coal-pile model is updated, and the volume difference between the new and old models is the total coal feeding amount generated by the single-knife feeding. By calculating the distance flow rate of the single stroke of the bucket wheel in real time through the bucket-wheel feeding trajectory, an effective technical means for precise coal blending is provided.

Description

Technical Field

[0001] The present invention relates to the technical field of safe operation in coal yards, and in particular to a method and system for calculating the flow rate of a single-blade reclaimer of a bucket wheel reclaimer. Background Art

[0002] As market coal prices reach historical highs year by year, there is a requirement for accurate coal blending in both thermal power production and port transportation. Accurate coal blending has become a technical means for companies to maximize profits.

[0003] Bucket wheel excavators are crucial equipment in thermal power plant fuel systems and port loading and unloading operations. Users often constantly monitor changes in the reclaimed material volume during the bucket wheel excavator's reclaiming process. This is because the fuel system's metering equipment is located remotely from the bucket wheel excavator's operating location, sometimes by several kilometers. Consequently, tens of tons of material can accumulate on the conveyor belt. Furthermore, due to the limited capacity of the raw coal bunkers in thermal power plants or the high limit of the ship's hold being reached during port loading, emergency stoppages of the conveyor belt or restarts under heavy loads can severely threaten the conveyor's service life and efficiency. Consequently, users struggle to accurately predict the reclaimed material volume for each coal type, making precise coal blending difficult. Summary of the Invention

[0004] In response to the above technical problems, a method and system for calculating the flow rate of a single-blade bucket wheel reclaimer is provided. The technical means adopted by the present invention are as follows:

[0005] A method for calculating the flow rate of a single-blade reclaimer of a bucket wheel reclaimer comprises the following steps:

[0006] Step 1: Grid the coal yard and unify the coal yard and bucket wheel excavator into a local coordinate system;

[0007] Step 2: Install a laser scanner on the bucket wheel machine, and determine the coordinates of the laser scanner in the coal yard coordinate system by adjusting the movement and posture of the bucket wheel machine;

[0008] Step 3: Initialize the vertical coordinate of the preset position in the coal yard to 0;

[0009] Step 4: The bucket wheel excavator is equipped with a laser scanner to perform a full-area scan of the coal yard;

[0010] Step 5: Triangulate the scanned data after the full-area scanning by the scanner and the preset points of the coal yard divided by gridding, and assign heights to all preset points in the triangulated coal yard;

[0011] Step 6: After the preset triangles in the coal yard are assigned heights, triangular prisms are formed. The volumes of all triangular prisms are calculated to obtain the total volume of the coal yard stockpile and the coal storage information of the coal yard is obtained.

[0012] Step 7: Obtain the three-dimensional position coordinates of the feature points on the bucket wheel in the coal yard, and traverse whether the preset points in the coal yard are within the newly built triangular mesh. If so, determine whether the height of the preset point is higher than the triangular surface. If it is higher, assign the average value of the heights of the three vertices; if it is lower, do not process.

[0013] Step 8: After single-knife coal fetching is completed, update the coal pile model, and the volume difference between the new and old models is the total coal feeding volume generated by single-knife coal fetching.

[0014] Further, the bucket wheel stacker-reclaimer is a cantilever type bucket wheel stacker-reclaimer, and there are two laser scanners, which are respectively installed on both sides of the end of the cantilever of the bucket wheel stacker-reclaimer. During the process of the cantilever type bucket wheel stacker-reclaimer performing travel scanning, the cantilever rotates to enable the two scanning heads to respectively obtain the scanning data of the inner and outer slopes. After moving to the travel limit, the scanning of the material pile at positions outside the limit is completed through the rotation action.

[0015] Further, after the overall laser scanner scans the original coal yard in step 2, the origin of the three-dimensional space coordinate is the projection of the 0 limit position of the bucket wheel stacker-reclaimer on the reference plane. The spatial coordinate position of the right coal yard inventory scanner in the coal yard is calculated through the following formula:

[0016]

[0017] Among them, L1 is the straight-line distance between the rotation center of the bucket wheel stacker-reclaimer and the pitching center point, L2 is the straight-line distance from the scanning head mounting bracket to the pitching center, L3 is the height of the scanning head fixed heightening bracket, L4 is the height between the cement surface of the travel mechanism track and the reference plane of the coal yard, L5 is the height between the pitching center point and the cement surface of the travel mechanism track, L6 and L7 are respectively the distances from the two laser scanner scanning heads to the center line of the cantilever, S is the travel data of the bucket wheel stacker-reclaimer, θ is the rotation angle, γ is the pitching angle, and m is the distance from the rotation center to the width boundary of the coal yard when the bucket wheel stacker-reclaimer is at the mechanical limit.

[0018] Further, in step 2, the single-cycle data set of the scanning data of the laser scanner is a plane polar coordinate array, and the point cloud data of the material pile is converted to the space rectangular coordinate system through the following formula:

[0019]

[0020] Among them, ρ is the scanned distance, α i is the scanning polar angle.

[0021] Further, in step 5, the point cloud data is converted according to formulas 1 and 2 in the rectangular coordinate system to obtain a set of rectangular coordinate arrays. Ignoring the height coordinate values of the converted point cloud, these point clouds are subjected to Delaunay triangulation and triangulation is carried out using the interpolation method.

[0022] Further, in step 7, feature points are selected, and the three-dimensional position coordinates of the feature points in the coal yard are calculated based on the following formula:

[0023]

[0024] where θ is the slewing angle of the boom of the bucket wheel stacker-reclaimer, γ is the pitching angle of the boom of the bucket wheel stacker-reclaimer, S is the traveling distance of the bucket wheel stacker-reclaimer, Δθ is the angle from the feature point to the center line of the boom, Δγ is the longitudinal angle between the spherical radii OA and OB and the upper plane of the boom, and l OA is the distance between the rotation center O of the bucket wheel and the feature point A.

[0025] Further, the bucket wheel stacker-reclaimer is a gantry bucket wheel stacker-reclaimer, and the spatial coordinates of the coal yard of the scanner are expressed as shown in Formula 2-1:

[0026]

[0027] In the formula: L is the horizontal distance from the scanner to the edge of the non-belt side track, H is the distance from the scanner to the initial height of the coal yard, a is the distance from the scanner to the center line of the top platform, m is the distance from the top center line to the mechanical limit of the rear wheel, and S is the traveling distance of the bucket wheel stacker-reclaimer.

[0028] Further, in step 2, the single-cycle data set of the scan data of the laser scanner is a plane polar coordinate array, and the point cloud data of the stockpile is converted to a spatial rectangular coordinate system through the following formula:

[0029]

[0030] where ρ is the scanned distance, and α i is the scan polar angle.

[0031] Further, in step 7, feature points are selected, and the three-dimensional position coordinates of the feature points in the coal yard are calculated based on the following formula:

[0032]

[0033]

[0034] R is the radius of the bucket wheel, h is the distance from the center of the bucket wheel to the horizontal line of the height measurement point of the movable beam, F is the height detection data of the movable beam, and E is the stroke distance of the bucket wheel.

[0035] A single-knife coal fetching flow calculation system for a bucket wheel reclaimer, comprising a bucket wheel stacker-reclaimer, a laser scanner, and a control system. The laser scanner is connected to the control system, the laser scanner is arranged on the bucket wheel stacker-reclaimer, and the bucket wheel stacker-reclaimer is connected to the control system.

[0036] The control system includes:

[0037] A coordinate system construction and grid division unit, which is used to obtain the spatial information of the coal yard and divide the coal yard coordinate system into a grid structure with preset coordinate points based on a preset side length;

[0038] A coordinate conversion unit, which is used to perform coordinate conversion on the scanning data of the laser scanner so that the point cloud data of the stockpile collected is converted to a spatial rectangular coordinate system;

[0039] An interpolation and mesh generation unit, which is used to perform Delaunay triangulation on the rectangular coordinate array of the laser scanner scanning data. After the triangulation is completed, the vertex indices of all triangles in this point cloud acquisition period are counted;

[0040] A bottom surface reconstruction unit, which is used to perform Delaunay triangulation on the set of characteristic point trajectory points during one stroke of the coal bucket wheel. After the triangulation is completed, it traverses whether the preset points in the coal yard are within the newly built triangular grid, and performs Delaunay sub-triangle processing based on the traversal results to reconstruct the working surface of the coal pile;

[0041] A volume calculation unit, which is used to assign heights to the triangles constructed by the interpolation and mesh generation unit and the bottom surface reconstruction unit, and obtain the total volume of the coal yard stockpile based on the volumes of all triangular prisms;

[0042] The bucket wheel includes a cantilever bucket wheel or a gantry bucket wheel.

[0043] The present invention uses a three-dimensional laser scanner to scan the coal stacks in the yard, and processes the scanned point cloud data including calculation, modeling and rendering to generate a three-dimensional model. Each point in the three-dimensional model has a coordinate value. A spatial three-dimensional coordinate system is established, and the positioning data of the stacker-reclaimer including traveling, lifting of the movable beam, and traveling of the bucket wheel are all incorporated into the spatial coordinate system. The cantilever bucket wheel includes traveling, cantilever rotation and pitching. The data is obtained from the plc system, and the distance flow of the bucket wheel single-stroke coal taking is calculated in real time through the bucket wheel coal taking trajectory, so that the user can accurately predict the single-knife coal taking amount of the coal type, providing an effective technical means for safe production and precise coal blending. Description of the Drawings

[0044] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0045] Figure 1 It is a schematic diagram of the grid division of the coal yard of the cantilever bucket wheel and the assignment of the coordinate heights of the preset points in Embodiment 1 of the present invention.

[0046] Figure 2 This is a simple installation diagram of the laser scanner at the end of the cantilever bucket wheel stacker-reclaimer in Embodiment 1 of the present invention.

[0047] Figure 3 This is a schematic diagram of the cantilever bucket wheel stacker-reclaimer carrying a laser scanner for full-field scanning of the coal yard in Embodiment 1 of the present invention.

[0048] Figure 4 This is a schematic diagram of coal yard height assignment in Embodiment 1 of the present invention.

[0049] Figure 5 This is a flowchart in Embodiment 1 of the present invention.

[0050] Figure 6 This is a schematic diagram of feature point selection on the bucket wheel in Embodiment 1 of the present invention.

[0051] Figure 7 This is a schematic diagram of the relative position relationship between the feature points on the bucket wheel and the cantilever of the bucket wheel stacker-reclaimer in Embodiment 1 of the present invention.

[0052] Figure 8 This is a schematic diagram of grid division of the coal yard and coordinate height assignment of preset points on the gantry bucket wheel stacker-reclaimer in Embodiment 2 of the present invention.

[0053] Figure 9 This is an installation diagram of the scanner on the gantry bucket wheel stacker-reclaimer in Embodiment 2 of the present invention.

[0054] Figure 10 This is a schematic diagram of the scanning process of the gantry bucket wheel stacker-reclaimer in Embodiment 2 of the present invention.

[0055] Figure 11 This is a schematic diagram of feature point selection on the gantry bucket wheel stacker-reclaimer in Embodiment 2 of the present invention. Detailed implementation manners

[0056] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0057] This embodiment discloses a single-knife coal fetching flow calculation method for a bucket wheel reclaimer, including the following steps:

[0058] Step 1: Divide the coal yard into grids and unify the coal yard and the bucket wheel stacker-reclaimer into a local coordinate system;

[0059] Step 2: Install a laser scanner on the bucket wheel stacker. Determine the coordinates of the laser scanner in the coal yard coordinate system by adjusting the travel and attitude of the bucket wheel stacker.

[0060] Step 3: Initialize the ordinate of the preset points in the coal yard to 0.

[0061] Step 4: The bucket wheel stacker equipped with a laser scanner performs a full-field scan of the coal yard.

[0062] Step 5: Triangulate the scan data after the full-field scan of the scanner with the preset points of the meshed coal yard, and assign heights to all preset points in the triangulated coal yard.

[0063] Step 6: After the preset triangles in the coal yard are assigned heights to form triangular prisms, calculate the volumes of all triangular prisms to obtain the total volume of the coal yard stockpile, and obtain the coal storage information of the coal yard.

[0064] Step 7: Obtain the three-dimensional position coordinates of the feature points on the bucket wheel in the coal yard. Traverse whether the preset points in the coal yard are within the newly created triangular mesh. If so, determine whether the height of the preset point is higher than the triangular surface. If it is higher, assign the average value of the heights of the three vertices; if it is lower, do not process.

[0065] Step 8: After single-knife coal taking is completed, update the coal pile model. The volume difference between the new and old models is the total coal feeding volume generated by single-knife coal taking.

[0066] Embodiment 1

[0067] As Figure 5 shown, in this embodiment, the bucket wheel stacker is a cantilever type bucket wheel stacker. Taking the cantilever type bucket wheel stacker as an example for coal yard meshing addressing, the x and y coordinate values of the coal yard are fixedly set, corresponding to a fixed area of the coal yard. In this way, the change of the coal yard is only the change of the height z value. Unify the coal yard and the bucket wheel stacker into a local coordinate system, and calculate the running track of the bucket wheel stacker and the coordinates of the bucket wheel stacker in real time, so as to accurately track the position of the bucket wheel stacker and calculate the spatial position relationship with the coal yard stockpile.

[0068] Taking a 60 * 300M strip coal yard as an example, set the side length of the grid to 0.25m and initialize the coal yard into 72,000 squares, 144,000 right triangles, and 289,441 preset coordinate points; as Figure 1 shown, establish a space rectangular coordinate system with the straight line parallel to the coal yard boundary where the projection point of the bucket wheel rotation center to the ground is located as the X axis and the east width line of the coal yard as the Y axis.

[0069] As Figure 2The figure shows the installation of a laser scanner on a cantilever bucket wheel excavator. To align the coal yard stockpile location data with the bucket wheel excavator's boom and bucket wheel positions within the same space and enable comprehensive, no-blind-angle scanning of the coal yard, two SICK-3601 scanner heads were mounted at the ends of the bucket wheel excavator's boom to provide a better field of view at high pitch. Furthermore, the height of the scanner head mounting bracket was raised to 4 meters. During the bucket wheel excavator's travel scanning process, the boom rotates 135°, allowing the two scanner heads to obtain data from the inner and outer slopes. After reaching the travel limit, the boom rotates to scan positions outside the limit. During the cantilever bucket wheel excavator's travel scanning process, the boom rotates, allowing the two scanner heads to obtain data from the inner and outer slopes. After reaching the travel limit, the boom rotates to scan positions outside the limit.

[0070] Step 2: After the laser scanner scans the raw coal yard, the origin of the three-dimensional spatial coordinate is the projection of the bucket wheel machine's zero limit on the reference plane. The spatial coordinate position of the right coal pan meter in the coal yard is calculated using the following formula:

[0071]

[0072] Among them, L1 is the straight-line distance between the bucket wheel excavator's rotation center and the pitch center point, L2 is the straight-line distance between the scanner head mounting bracket and the pitch center point, L3 is the height of the scanner head fixed raising bracket, L4 is the height between the cement surface of the traveling mechanism track and the coal yard reference plane, L5 is the height between the pitch center point and the cement surface of the traveling mechanism track, L6 and L7 are the distances from the two laser scanner heads to the cantilever center line, S is the bucket wheel excavator's running data, θ is the rotation angle, γ is the pitch angle, and m is the distance from the rotation center of the bucket wheel excavator to the coal yard width boundary when the bucket wheel excavator is at the mechanical limit.

[0073] The SICK-3601's single-cycle scan data dataset is a planar polar coordinate array with two dimensions: [scanning distance, scanning angle]. The cantilever extension direction is defined as the positive polar axis direction, and the data recovered from below the scanning head is used as the valid data acquisition interface. The minimum data unit for valid data is approximately 2°, so a single scan cycle collects approximately 90 valid data points within the 0-180° range. The laser scanner's single-cycle scan data dataset is a planar polar coordinate array. The following formula is used to convert the stockpile's point cloud data into a spatial rectangular coordinate system:

[0074]

[0075] Among them, ρ is the scanned distance, α i is the scanning polar angle, where And i≤90.

[0076] S01. Initialize the ordinate of the preset point in the coal yard to 0.

[0077] S02. The bucket wheel reclaimer travels to the 0-meter limit, rotates to the left limit of 5 degrees, and the pitch angle is raised to the maximum of 8.5 degrees.

[0078] S02-1. As Figure 3 shown, the bucket wheel reclaimer performs a scanning operation. First, the boom performs a rotation operation, rotating from 5 degrees to 135 degrees to complete the rotational scan; the bucket wheel reclaimer performs a traveling operation, traveling from 0 meters to 256 meters to complete the traveling scan process; after reaching the 256-meter limit, the boom rotation operation is performed, and the boom rotates from 135 degrees to 175 degrees to complete the rotational scan. By completing the above operations, it is ensured that the laser line scans the entire coal yard comprehensively and without dead angles once.

[0079] S02-2. As Figure 1 shown in the left local enlarged schematic diagram, the peripheral emission frequency of the SICK scanner is 25 Hz. The system sends an instruction once per second to obtain the scan data of the scanner, forms a point cloud array from two laser points, and converts the point cloud data into a rectangular coordinate array according to Formulas 1-1 and 1-2. Ignoring the height coordinate values of the point cloud after conversion, Delaunay triangulation is performed on these point clouds. Using the super triangle OAB in the figure as the initial triangle (this triangle contains all points within the coal yard area), triangulation is performed using the interpolation method. The specific method is as follows:

[0080] (1) Construct a super triangle OAB that contains the point array;

[0081] (2) Insert any point M in the array into the existing triangular mesh.

[0082] (3) Find the triangle where M is located, connect the vertices of the triangle to M, and generate three new triangles.

[0083] (4) Perform triangle reconstruction, update the triangle set, and write the vertex coordinates of the new triangle into the triangle set.

[0084] (5) Repeat steps (2), (3), and (4) until all points have been inserted.

[0085] (6) Remove the triangles whose vertices include the vertices of the super triangle among all vertices.

[0086] After triangulation is completed, count the vertex indices of all triangles within this point cloud acquisition period, and determine whether there is a preset point within any triangle of the constructed triangular mesh during this period. The judgment method is as follows:

[0087] (1) Select the rectangular area composed of the maximum and minimum values of the horizontal and vertical coordinates within the point cloud acquisition period, and extract all preset points within this area;

[0088] (2) Propose the triangle vertex coordinates A in the triangular mesh set i , B i , C i (i is the index of the triangle in the Delaunay triangular mesh),

[0089] (3) Sequentially extract all preset points P in the rectangular area within one network construction period j (j is the index of the preset point in the rectangular area), and calculate the cross product results of vectors respectively: m = A i P j ^B i P j n = A i P j ^C i P j h = C i P j ^B i P j ; if m, n, h have the same sign (both positive or both negative), then P j is inside this triangle, otherwise it is outside the triangle;

[0090] (4) When there is a preset point inside a certain triangle, assign the weighted average of the height coordinates of the three vertices of the triangle to the height coordinate of the preset point;

[0091] S02-3. After the overall scan is completed, all preset points in the coal yard will be assigned heights as Figure 4 shown.

[0092] As Figure 1 shown in the enlarged view on the right, after the preset triangles in the coal yard are assigned heights, they will form a triangular prism. Calculate the volumes of all triangular prisms to obtain the total volume of the coal yard stockpile, thereby obtaining the coal storage information of the coal yard.

[0093] S03. As Figure 6 shown, the positions of the characteristic points selected on the bucket wheel are as follows. In this embodiment, the two points on the lower sides of the bucket wheel and the two points on the bucket wheel at a 45° angle diagonally downward are selected as characteristic points, and their position coordinates are calculated as follows:

[0094] S04. As Figure 7 shown, the characteristic points A and B selected in the embodiment are spherical coordinates with the center of rotation O of the bucket wheel as the center of the sphere and OA and OB as the radii. According to on-site measurement and calculation, the horizontal distances between the characteristic points A and B and the central axis of the boom and the vertical distances to the upper plane of the boom can be obtained. From this, the angles Δθ between the characteristic points and the central axis of the boom and the longitudinal angles Δγ between the spherical radii OA and OB and the upper plane of the boom can be calculated. Taking point A as an example, its spherical coordinate expression is shown in formula (1-3)

[0095]

[0096] Among them, θ is the slewing angle of the boom of the bucket wheel stacker-reclaimer, γ is the pitching angle of the boom of the bucket wheel stacker-reclaimer, and S is the traveling distance of the bucket wheel stacker-reclaimer. Thus, the three-dimensional position coordinates of point A in the coal yard can be calculated.

[0097] S05. As Figure 6 shown, using the position coordinates of the four selected points, the real-time position data of the bucket wheel stacker-reclaimer is obtained through the OPC interface. With a slewing interval of 2°, the spatial position coordinates of the selected feature points are recorded. When the bucket wheel completes a slewing and feeding operation, all the feature points on the feeding trajectory are recorded and the Delaunay triangulation network is constructed. Then, it is traversed whether the preset points in the coal yard are within the newly built triangular grid. If so, it is judged whether the height of the preset point is higher than the triangular surface, and then it is judged whether the height coordinate of the current preset point is higher than the average height of the three vertices of the Delaunay sub-triangle where it is located. If it is higher, it is assigned the average height of the three vertices; if it is lower, no processing is done. In this embodiment, the four points refer to the feature points selected on the bucket wheel, and these feature points will change with the attitude of the bucket wheel stacker-reclaimer. After completing a slewing operation, a set of point sets can be obtained according to these four points. By performing Delaunay triangulation on these point sets, the height of the preset points within the triangular network can be determined. Since the bucket wheel movement trajectory of the gantry bucket wheel stacker-reclaimer in Embodiment 2 is relatively simple, only 2 points are selected to construct the network.

[0098] S08. After the single-knife feeding is completed, the coal pile model is rebuilt and updated according to the steps of S05, and the volume difference between the new and old models is the total coal feeding amount generated by the single-knife feeding.

[0099] Embodiment 2

[0100] In this embodiment, the bucket wheel stacker-reclaimer is a gantry bucket wheel stacker-reclaimer. Taking the gantry bucket wheel stacker-reclaimer as an example, the coal yard is grid-address coded. The x and y coordinate values of the coal yard are fixedly set corresponding to the fixed area of the coal yard, so the change of the coal yard is only the change of the height z value. The coal yard and the bucket wheel stacker-reclaimer are unified into a local coordinate system, and the running trajectory of the bucket wheel stacker-reclaimer and the coordinates of the bucket wheel are calculated in real time, so that the position of the bucket wheel can be accurately tracked and the spatial position relationship with the coal pile in the coal yard can be calculated.

[0101] Taking a 60 * 300M strip coal yard as an example, the side length of the grid is set to 0.25m, and the coal yard is initialized into 72,000 squares, 144,000 right triangles, and 289,441 preset coordinate points; as Figure 8 shown, with the retracting mechanical limit of the rear traveling wheel of the gantry bucket wheel stacker-reclaimer as the coordinate origin, the forward direction line of the non-belt side track as the X axis, and the north-south width line of the coal yard as the Y axis, a space rectangular coordinate system is established.

[0102] Calculating the coordinates of the laser scanner in the coal yard: As Figure 9 shown in the installation schematic diagram of the laser scanner on the gantry bucket wheel reclaimer. Taking the scanner on the left origin side as an example, the bucket wheel reclaimer is a gantry bucket wheel reclaimer, and two scanners are also selected, so that the coal yard can be scanned to the greatest extent whether the bucket wheel reclaimer moves forward or backward. The spatial coordinates of the scanner in the coal yard are expressed as shown in Formula 2-1:

[0103]

[0104] In the formula: L is the horizontal distance from the scanner to the edge of the non-belt side track, H is the distance from the scanner to the initial height of the coal yard, a is the distance from the scanner to the center line of the top platform, m is the distance from the top center line to the mechanical limit of the rear wheel, and S is the traveling distance of the bucket wheel reclaimer.

[0105] The single-cycle data set of the scanning data of SICK-3601 is a plane polar coordinate array with a dimension of 2: [scanning distance, scanning angle]. It is stipulated that the cantilever extension direction is the positive direction of the polar axis, and the data collected under the scanning head is the effective data acquisition interface. Allocate approximately 2° as the minimum data unit of an effective data. Then, about 90 pieces of effective data are collected in a single scanning cycle within the range of 0 to 180°. Because the bucket wheel diameter of the gantry bucket wheel reclaimer is relatively large and exceeds the width of the top platform, in order to make the laser emitted by the scanner avoid the bucket wheel during installation, the scanning head needs to be tilted forward by a certain angle γ. Therefore, the laser points emitted by the scanner are projected onto the coordinate system as a backward-tilted straight line. The laser point coordinates of a single scanning cycle are shown in

[0106] Formula 2-2:

[0107]

[0108] Among them, ρ is the scanning distance, and α i is the scanning polar angle, where and i ≤ 90.

[0109] S21. Initialize the ordinate of the preset point in the coal yard to 0.

[0110] S22-1. As Figure 10 shown, the bucket wheel reclaimer starts walking to the 0-meter limit and issues a forward command. The bucket wheel reclaimer walks from the 0-meter limit to the 275-meter limit to complete a comprehensive scan of the coal yard.

[0111] S22-2. As Figure 8The left - hand partial enlarged view shown. The peripheral emission frequency of the SICK scanner is 25 Hz. The system sends an instruction once per second to obtain the scan data of the scanner, forms a point cloud array from two sets of laser points, and converts the point cloud data into a rectangular coordinate system according to Formulas 2 - 1 and 2 - 2 to obtain a set of rectangular coordinate arrays.

[0112] Ignore the height coordinate values of the point cloud after conversion. Triangulate these point clouds using Delaunay triangulation. Use the super - triangle OAB in the figure as the initial triangle (this triangle contains all points within the coal yard area), and construct the network using the interpolation method. The specific method is as follows:

[0113] (1) Construct a super - triangle OAB that contains the point array;

[0114] (2) Insert any point M in the array into the existing triangular network.

[0115] (3) Find the triangle where M is located, connect the vertices of the triangle to M, and generate three new triangles.

[0116] (4) Perform triangle reconstruction, update the triangle set, and write the vertex coordinates of the new triangles into the triangle set.

[0117] (5) Repeat steps (2), (3), and (4) until all points have been inserted.

[0118] (6) Remove the triangles whose vertices include the vertices of the super - triangle from all vertices.

[0119] After the network construction is completed, count the vertex indices of all triangles within this point cloud acquisition period, and determine whether there is a preset point within any triangle of the constructed triangular network during this period. The determination method is as follows:

[0120] (1) Select the maximum and minimum values of the horizontal and vertical coordinates within the point cloud acquisition period to form a rectangular area, and extract all preset points within this area;

[0121] (2) Extract the triangle vertex coordinates A i , B i , C i (i is the index of the triangle in the Delaunay triangular network),

[0122] (3) Sequentially extract all preset points P j (j is the index of the preset point within the rectangular area) within the rectangular area in one network construction period, and calculate the vector cross - product results m = A i P j ^B i P j n = A i P j ^Ci P j h = C i P j ^B i P j ; If m, n, and h have the same sign (both positive or both negative), then P j is inside this triangle; otherwise, it is outside the triangle;

[0123] (4) When there is a preset point inside a certain triangle, assign the weighted average of the height coordinates of the three vertices of this triangle to the height coordinate of the preset point.

[0124] When there is a preset point inside a certain triangle, assign the weighted average of the height coordinates of the three vertices of this triangle to the height coordinate of the preset point.

[0125] S02 - 3. After the overall scan is completed, all preset points in the coal yard will be assigned the indicated height. As Figure 8 shown in the enlarged right - hand figure, after the preset triangles in the coal yard are assigned heights, they will form a triangular prism. Calculate the volumes of all the triangular prisms to obtain the total volume of the coal yard stockpile, thereby obtaining the coal storage information of the coal yard.

[0126] S03. As Figure 11 shown, in this embodiment, 2 feature point coordinates are selected on the bucket wheel, which are the lowest point on the inner side of the bucket wheel and the edge point on the inner side of the bucket wheel that slopes downward at 45° from the center of the circle. Let the radius of the bucket wheel be R, the distance from the center of the bucket wheel to the horizontal line of the height measurement point of the movable beam be h, the height detection data of the movable beam be F, and the travel distance of the bucket wheel be E. Then the spatial coordinates of feature points 1 and 2 are as shown in Formulas 2 - 3 and 2 - 4:

[0127]

[0128]

[0129] S04. Taking one travel of the bucket wheel at the coal - taking position as the basis, collect a set of points with a group of feature points every 0.5 meters, and perform Delaunay triangulation on this set of points.

[0130] S05. Using the triangular mesh obtained from the position coordinates of the two selected points in one travel, traverse whether the preset points in the coal yard are within the newly built triangular grid. If so, determine whether the height of the preset point is higher than the triangular surface, and then determine whether the current height coordinate of the preset point is higher than the average height of the three vertices of the Delaunay sub - triangle where it is located. If it is higher, assign it the average value of the three vertex heights; if it is lower, do not process it.

[0131] S08. After the single-pass coal fetching of the current position is completed, the coal pile model is re-modeled and updated according to the steps of S05, and the volume difference between the new and old models is the total coal feeding volume generated by the single-pass coal fetching.

[0132] A single-pass coal fetching flow calculation system for a bucket wheel reclaimer, comprising a bucket wheel reclaimer, a laser scanner and a control system. The laser scanner is connected to the control system, the laser scanner is arranged on the bucket wheel reclaimer, and the bucket wheel reclaimer is connected to the control system.

[0133] The control system includes:

[0134] A coordinate system construction and grid division unit, configured to obtain the spatial information of the coal yard and divide the coal yard coordinate system into a grid structure with preset coordinate points based on a preset side length;

[0135] A coordinate conversion unit, configured to perform coordinate conversion on the scanning data of the laser scanner, so that the point cloud data of the material pile collected is converted to a spatial rectangular coordinate system;

[0136] An interpolation and triangulation unit, configured to perform Delaunay triangulation on the rectangular coordinate array of the scanning data of the laser scanner. After the triangulation is completed, the vertex indices of all triangles within this point cloud acquisition period are counted;

[0137] A bottom surface reconstruction unit, configured to perform Delaunay triangulation on the characteristic point trajectory point set during one stroke of the coal fetching bucket wheel. After the triangulation is completed, it traverses whether the preset points in the coal yard are within the newly built triangular grid, and performs Delaunay sub-triangle processing based on the traversal result to reconstruct the coal pile working surface;

[0138] A volume calculation unit, configured to assign heights to the triangles constructed by the interpolation and triangulation unit and the bottom surface reconstruction unit, and obtain the total volume of the coal yard material pile based on the volumes of all triangular prisms.

[0139] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for calculating the single-blade material-taking flow rate of a bucket-wheel reclaimer, characterized in that, It includes the following steps: Step 1: Divide the coal yard into grids, and unify the coal yard and the bucket wheel reclaimer into a local coordinate system; Step 2: Set a laser scanner on the bucket wheel reclaimer. By adjusting the travel and attitude of the bucket wheel reclaimer, determine the coordinates of the laser scanner in the coal yard coordinate system; Step 3: Initialize the ordinate of the preset points in the coal yard to 0; Step 4: The bucket wheel reclaimer equipped with a laser scanner performs a full-field scan of the coal yard; Step 5: Perform Delaunay triangulation on the scan data after the full-field scan by the scanner and the preset points of the gridded coal yard, and assign heights to all preset points in the Delaunay triangulated coal yard; Step 6: After the preset triangles in the coal yard are assigned heights to form triangular prisms, calculate the volumes of all triangular prisms to obtain the total volume of the coal yard stockpile, and obtain the coal storage information of the coal yard; Step 7: Select the two points on both sides directly below the bucket wheel and the two points on both sides of the bucket wheel at a 45° angle diagonally below as feature points, obtain the three-dimensional position coordinates of the feature points on the bucket wheel in the coal yard, use the position coordinates of the four selected points, obtain the real-time position data of the bucket wheel reclaimer through the OPC interface, record the spatial position coordinates of the selected feature points at a 2° rotation interval, and when the bucket wheel completes a rotation and reclaimer operation, record all the feature points on the reclaimer trajectory and complete the construction of Delaunay triangulation, determine the height of the preset points within the Delaunay triangulation, traverse whether the preset points in the coal yard are within the newly built triangular grid, if so, judge whether the height of the preset points is higher than the triangular surface, if higher, assign the average value of the heights of the three vertices, and if lower, do not process; Step 8: After the single-knife reclaimer operation is completed, the coal pile model is updated, and the volume difference between the new and old models is the total amount of coal fed by the single-knife reclaimer operation; The bucket wheel reclaimer is a cantilever type bucket wheel reclaimer, and there are two laser scanners, which are respectively installed on both sides of the end of the bucket wheel reclaimer's boom. During the process of the cantilever type bucket wheel reclaimer performing travel scanning, the boom rotates so that the two scanning heads respectively obtain the scan data of the inner and outer slopes. After moving to the travel limit, complete the scan of the stockpile at positions outside the limit through the rotation action; After the overall laser scanner in Step 2 scans the original coal yard, the origin of the three-dimensional space coordinate is the projection of the 0 limit position of the bucket wheel reclaimer on the reference plane. The spatial coordinate position of the right coal yard inventory meter in the coal yard is calculated through the following formula: （1-1） Wherein, L1 is the straight-line distance between the slewing center of the bucket wheel stacker-reclaimer and the pitching center point, L2 is the straight-line distance from the mounting bracket of the scanning head to the pitching center, L3 is the height of the fixed heightening bracket of the scanning head, L4 is the height between the cement surface of the traveling mechanism track and the reference surface of the coal yard, L5 is the height between the pitching center point and the cement surface of the traveling mechanism track, L6 and L7 are the distances from the scanning heads of the two laser scanners to the center line of the boom respectively, and S is the traveling data of the bucket wheel stacker-reclaimer. is the slewing angle, is the pitching angle, and m is the distance from the slewing center to the width boundary of the coal yard when the bucket wheel stacker-reclaimer is at the mechanical limit. In Step 7, select feature points, and calculate the three-dimensional position coordinates of the feature points in the coal yard based on the following formula: Among them, θ is the slewing angle of the boom of the bucket wheel stacker, γ is the pitching angle of the boom of the bucket wheel stacker, S is the traveling distance of the bucket wheel stacker, ∆θ is the angle from the feature point to the center line of the boom, ∆γ is the longitudinal angle between the spherical radii OA and OB and the upper plane of the boom, and l OA is the distance between the rotation center O of the bucket wheel stacker and the feature point A.

2. The single-knife material taking flow calculation method of the bucket wheel reclaimer according to claim 1, characterized in that In Step 2, the single-cycle data set of the scan data of the laser scanner is a plane polar coordinate array. Convert the point cloud data of the stockpile to a spatial rectangular coordinate system through the following formula: （1-2） Among them, is the scanned distance, is the scanned polar angle.

3. The single-knife material taking flow calculation method of the bucket wheel reclaimer according to claim 2, characterized in that, In Step 5, convert the point cloud data according to Formulas 1-1 and 1-2 to obtain a set of rectangular coordinate arrays, ignore the height coordinate values of the point cloud after conversion, perform Delaunay triangulation on these point clouds, and use the interpolation method for triangulation.

4. A single-knife material taking flow calculation system for a bucket wheel reclaimer based on the calculation method described in claim 1, characterized in that, It includes a bucket wheel reclaimer, a laser scanner, and a control system. The laser scanner is connected to the control system. The laser scanner is set on the bucket wheel reclaimer, and the bucket wheel reclaimer is connected to the control system. The control system includes: Coordinate system construction and grid division unit, which is used to obtain the spatial information of the coal yard and divide the coal yard coordinate system into a grid structure with preset coordinate points based on a preset side length; Coordinate conversion unit, which is used to perform coordinate conversion on the scanning data of the laser scanner, so that the point cloud data of the stockpile collected is converted to a spatial rectangular coordinate system; Interpolation and mesh generation unit, which is used to perform Delaunay triangulation on the rectangular coordinate array of the laser scanner scanning data. After the mesh generation is completed, the vertex indices of all triangles in this point cloud acquisition period are counted; Bottom surface reconstruction unit, which is used to perform Delaunay triangulation on the characteristic point trajectory point set during a single trip of the coal bucket wheel. After the mesh generation is completed, it traverses whether the preset points in the coal yard are within the newly built triangular mesh, and performs Delaunay sub-triangle processing based on the traversal results to reconstruct the coal face; Volume calculation unit, which is used to assign heights to the triangles constructed by the interpolation and mesh generation unit and the bottom surface reconstruction unit, and obtain the total volume of the stockpile in the coal yard based on the volumes of all triangular prisms; and is used to calculate the volume difference between the old and new models after the single-blade coal taking is completed and the coal pile model is updated.

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