Coal quality point cloud boundary point data processing method for coal preparation plant silo and related components

Abstract

The application relates to a coal quality point cloud boundary point data processing method for a coal preparation plant and related components, and applies to the technical field of data processing of the coal preparation plant. The method comprises the following steps: obtaining an original point set; calculating the normal direction of each original point in the original point set; determining a first boundary point and a second boundary point based on the normal direction, the distance between each original point and a preset point spacing; fitting the xy plane coordinates of the first boundary point by using a linear least square method and a standard equation of a circle, and calculating the center coordinates of the circle; scaling the first boundary point based on the center coordinates of the circle to determine a projection point; determining an interpolation point based on the projection point, the first boundary point and the preset point spacing; correcting the z value of the projection point and the interpolation point based on the first boundary point and the second boundary point; and determining a target point set based on the original point set, the corrected projection point and the corrected interpolation point. The application has the effect of improving the comprehensiveness and accuracy of coal quality point cloud data.

Description

Technical Field

[0001] This application relates to the technical field of data processing in coal preparation plants, and in particular to a method and related components for processing boundary point data of coal quality point cloud in coal preparation plant silos. Background Technology

[0002] In the production and operation of coal preparation plants, accurate monitoring of coal quality within the silos is crucial. Accurate data acquisition helps coal preparation plants rationally plan production, precisely allocate resources, improve coal preparation efficiency and product quality, and reduce production costs. With continuous technological advancements, the demands for automation and data processing accuracy in coal preparation plants are constantly increasing, driving the continuous development of related data acquisition and processing technologies.

[0003] Radar level gauges are commonly used data acquisition devices in the initial data collection of coal preparation plant silos. However, because the reflectivity of the silo sidewall and the curved surface of coal is quite similar, it is difficult to distinguish between the two when using radar level gauges for detection. To address this, a common approach is to reduce the initial data acquisition range designed for the site, making the acquisition range smaller than the actual size of the silo, thereby avoiding the acquisition of data from the silo wall during the detection process.

[0004] However, this method has obvious drawbacks. Narrowing the collection area results in the inability to collect data on coal quality near the silo wall, creating blind spots in the collection area. Consequently, the collected data cannot fully and accurately reflect the true distribution of coal quality within the silo, which in turn adversely affects the subsequent production decisions and process flow arrangements of the coal preparation plant. Summary of the Invention

[0005] To reasonably compensate for blind spots caused by the collection range being smaller than the actual size of the silo, and to improve the comprehensiveness and accuracy of coal quality point cloud data, this application provides a method for processing boundary point data of coal quality point cloud in coal preparation plant silos and related components.

[0006] Firstly, this application provides a method for processing boundary point data of coal quality point cloud in coal preparation plant silos, employing the following technical solution:

[0007] A method for processing boundary point data of coal quality point cloud in a coal preparation plant silo, comprising:

[0008] Obtain the original point set, which is based on data collected by a 3D millimeter-wave radar level gauge;

[0009] Calculate the normal direction of each original point in the set of original points;

[0010] The first boundary point is determined based on the normal direction, the distance between each of the original points, and the preset point spacing.

[0011] The second boundary point is determined based on the normal direction of each original point in the first point set, the distance between each original point, and the preset point spacing. The first point set is the point set after removing the first boundary point from the original point set.

[0012] The xy-plane coordinates of the first boundary point are fitted using the linear least squares method and the standard equation of a circle, the standard equation parameter values ​​of the circle are calculated, and the center coordinates of the circle are calculated based on the standard equation parameter values.

[0013] Based on a preset method and the center coordinates of the circle, the first boundary point is projected and scaled to determine the projection point;

[0014] The interpolation point is determined based on the projection point, the first boundary point, and the preset point spacing.

[0015] Correct the z-values ​​of the projection point and the interpolation point based on the first boundary point and the second boundary point;

[0016] The target point set is determined based on the original point set, the corrected projection points, and the corrected interpolation points.

[0017] By adopting the above technical solution, the original point set can be collected using a 3D millimeter-wave radar level gauge, which can achieve high accuracy. Calculating the normal direction of the original points and determining the first and second boundary points based on the normal direction can define the boundary range of the original point set. By fitting the xy-plane coordinates of the first boundary point to calculate the center coordinates, and projecting and scaling the first boundary point based on the center coordinates, the projection point can be determined. Combining the projection point, the first boundary point, and the preset point spacing to determine the interpolation point can supplement the data in the boundary blind area. Correcting the z-value of the projection point and the interpolation point can make the data more accurate. Finally, combining the original point set, the corrected projection point, and the interpolation point to determine the target point set can achieve reasonable compensation and filling of the boundary point data blind area of ​​the coal quality point cloud in the coal preparation plant silo, improving the comprehensiveness and accuracy of the coal quality point cloud data.

[0018] Optionally, calculating the normal direction of each original point in the original point set includes:

[0019] Traverse each of the original points in the set of original points, and determine the normal direction of the first current original point in turn, wherein the first current original point is the original point being traversed.

[0020] Determining the normal direction of the first current origin point includes:

[0021] Calculate the first distance between the first current origin point and each of the origin points in the set of origin points;

[0022] The original points are sorted in ascending order according to the first distance, and the first preset number of original points in the sort are determined as neighboring points;

[0023] Calculate the covariance matrix based on the first current original point and the neighboring points;

[0024] The covariance matrix is ​​subjected to eigenvalue decomposition to determine multiple eigenvalues ​​and the eigenvector corresponding to each eigenvalue;

[0025] The direction of the eigenvector corresponding to the smallest eigenvalue is determined as the normal direction of the first current original point.

[0026] By adopting the above technical solution, for the original point set of coal quality point cloud in coal preparation plant silos, each original point is traversed. By calculating the distance between the first current original point and other original points, sorting to determine neighboring points, calculating the covariance matrix, and performing eigenvalue decomposition, the normal direction of each original point can be accurately determined. This provides a basis for subsequently determining the first and second boundary points based on the normal direction, which in turn helps to process the boundary point data of coal quality point cloud in coal preparation plant silos, reasonably compensate for the blind spots caused by the collection range being smaller than the actual size of the silo, and improve the comprehensiveness and accuracy of coal quality point cloud data.

[0027] Optionally, determining the first boundary point based on the normal direction, the distance between each of the original points, and the preset point spacing includes:

[0028] Traverse each of the original points in the set of original points, and determine in turn whether the second current original point is the first boundary point. The second current original point is the original point being traversed.

[0029] The step of determining whether the second current original point is the first boundary point includes:

[0030] Based on the preset point spacing and the second distance between the second current original point and each of the original points in the set of original points, the neighbor points of the second current original point are determined;

[0031] If the angle between the normal direction of a neighboring point and the normal direction of the second current origin point is greater than a first preset angle, then the second current origin point is determined to be the first boundary point;

[0032] If there is no neighboring point whose normal direction is greater than the angle between the normal direction of the second current origin point and the normal direction of the second current origin point, then the second current origin point and the neighboring point are projected onto the xy plane, and the direction vector between the second current origin point and each neighboring point on the xy plane is determined. The direction vector is a vector pointing from the second current origin point to the neighboring point.

[0033] If there exists an angle between adjacent direction vectors that is greater than a second preset angle, then the second current original point is determined to be the first boundary point.

[0034] By adopting the above technical solution, based on the normal direction of the original point set, the second distance between each original point, and the preset point spacing, the first boundary point in the original point set can be accurately determined. This provides a basis for subsequent processing of the boundary point data of coal quality point cloud in the coal preparation plant silo, reasonable compensation for the blind spots caused by the on-site design, and estimation and filling of boundary point data.

[0035] Optionally, the step of projecting and scaling the first boundary point based on a preset method and the center coordinates to determine the projection point includes:

[0036] Obtain the radius of the silo;

[0037] Traverse the first boundary point and determine the projection point corresponding to the current first boundary point in turn. The current first boundary point is the first boundary point traversed in the current iteration.

[0038] Determining the projection point corresponding to the current first boundary point includes:

[0039] Calculate the azimuth angle of the current first boundary point relative to the center coordinates based on the x and y coordinates of the current first boundary point;

[0040] The first projection point is calculated based on the azimuth angle and the radius of the silo, and the first projection point is a two-dimensional coordinate in the xy plane;

[0041] The scaling factor of the current first boundary point is calculated based on the silo radius, the Euclidean distance formula, the x-coordinate and y-coordinate of the current first boundary point.

[0042] The second projection point is calculated based on the scaling factor, the x-coordinate and y-coordinate of the current first boundary point, and the second projection point is a two-dimensional coordinate in the xy plane;

[0043] Calculate the first arithmetic sum of the squares of the x and y coordinates of the first projection point;

[0044] Calculate the second arithmetic sum of the squares of the x and y coordinates of the second projection point;

[0045] If the first arithmetic sum of squares is greater than or equal to the second arithmetic sum of squares, then the projection point is determined based on the second projection point and the z-coordinate of the current first boundary point;

[0046] If the first arithmetic sum of squares is less than the second arithmetic sum of squares, then the projection point is determined based on the first projection point and the z-coordinate of the current first boundary point.

[0047] By adopting the above technical solution, the radius of the silo is obtained and the first boundary point is traversed. Based on the coordinates of the current first boundary point, the azimuth angle and the first projection point are calculated. At the same time, the scaling factor and the second projection point are calculated. Then, the final projection point is determined based on the comparison results of the arithmetic sum of squares. The algorithm can be used to project and scale the first boundary point, and reasonably estimate and fill the blind spots of the boundary point data of the coal quality point cloud of the coal preparation plant silo.

[0048] Optionally, determining the interpolation point based on the projection point, the first boundary point, and the preset point spacing includes:

[0049] Calculate the third distance between the first boundary point and the corresponding projection point;

[0050] If the third distance is greater than the fourth distance, then an interpolation point is inserted on the line connecting the first boundary point and the corresponding projection point based on the preset point spacing, wherein the fourth distance is a preset multiple of the preset point spacing;

[0051] The step of inserting interpolation points on the line connecting the first boundary point and the corresponding projection point based on the preset point spacing includes:

[0052] Starting from the first boundary point on the connecting line, an interpolation point is generated at every preset point spacing until the distance between the newly generated interpolation point and the projection point is less than or equal to the preset point spacing.

[0053] By adopting the above technical solution and setting interpolation points between the first boundary point and the projection point, the spacing between each point can be made more stable, thereby reducing the difficulty of subsequent surface reconstruction.

[0054] Optionally, correcting the z-values ​​of the projection point and the interpolation point based on the first boundary point and the second boundary point includes:

[0055] Construct the z-value correction equation;

[0056] Substitute the three-dimensional coordinates of the first boundary point and the second boundary point into the z-value correction equation to calculate the z-values ​​of the projection point and the interpolation point.

[0057] By adopting the above technical solution and correcting the z-values ​​of the projection points and interpolation points, the projection points and interpolation points become more accurate, which can achieve reasonable compensation and filling of the data blind spots of the coal quality point cloud boundary points in the coal preparation plant silos.

[0058] Optionally, determining the target point set based on the original point set, the corrected projected points, and the corrected interpolated points includes:

[0059] The corrected projection points and the corrected interpolation points are added to the original point set to generate the target point set;

[0060] The first neighboring point corresponding to the corrected projection point is determined based on the distance between every two points in the target point set and the second preset number.

[0061] If the distance between the first neighboring point and the projected point is less than a preset distance and the first neighboring point is the corrected interpolation point, then the first neighboring point is removed from the target point set.

[0062] The second neighboring point corresponding to the second boundary point is determined based on the distance between every two points in the target point set and the third preset number.

[0063] If the distance between the second neighboring point and the second boundary point is less than a preset distance and the second neighboring point is the corrected interpolation point, then the second neighboring point is removed from the target point set.

[0064] By adopting the above technical solution, the corrected projection points and interpolation points are added to the original point set to generate the target point set, which can supplement the missing data in the original point set and solve the problem of blind spots in coal quality data collection in coal preparation plant silos. By determining the first neighbor point of the projection point and the second neighbor point of the second boundary point, and removing interpolation points that are too close, redundant data in the target point set can be removed, making the target point set more accurate and reasonable.

[0065] Secondly, this application provides a data processing device for boundary points of coal quality point clouds in coal preparation plant silos, which adopts the following technical solution:

[0066] A coal quality point cloud boundary point data processing device for a coal preparation plant silo includes:

[0067] The original point set acquisition module is used to acquire the original point set, which is based on the data collected by the 3D millimeter-wave radar level gauge.

[0068] The normal direction determination module is used to calculate the normal direction of each original point in the original point set.

[0069] The first boundary point determination module is used to determine the first boundary point based on the normal direction, the distance between each of the original points and the preset point spacing.

[0070] The second boundary point determination module is used to determine the second boundary point based on the normal direction of each original point in the first point set, the distance between each original point, and the preset point spacing. The first point set is the point set after removing the first boundary point from the original point set.

[0071] The circle center coordinate determination module is used to fit the xy plane coordinates of the first boundary point using the linear least squares method and the standard equation of the circle, calculate the standard equation parameter values ​​of the circle, and calculate the circle center coordinates based on the standard equation parameter values.

[0072] The projection point determination module is used to project and scale the first boundary point based on a preset method and the center coordinates of the circle to determine the projection point.

[0073] An interpolation point determination module is used to determine an interpolation point based on the projection point, the first boundary point, and the preset point spacing.

[0074] The z-value correction module is used to correct the z-values ​​of the projection point and the interpolation point based on the first boundary point and the second boundary point.

[0075] The target point set determination module is used to determine the target point set based on the original point set, the corrected projection points, and the corrected interpolation points.

[0076] By adopting the above technical solution, the original point set can be collected using a 3D millimeter-wave radar level gauge, which can achieve high accuracy. Calculating the normal direction of the original points and determining the first and second boundary points based on the normal direction can define the boundary range of the original point set. By fitting the xy-plane coordinates of the first boundary point to calculate the center coordinates, and projecting and scaling the first boundary point based on the center coordinates, the projection point can be determined. Combining the projection point, the first boundary point, and the preset point spacing to determine the interpolation point can supplement the data in the boundary blind area. Correcting the z-value of the projection point and the interpolation point can make the data more accurate. Finally, combining the original point set, the corrected projection point, and the interpolation point to determine the target point set can achieve reasonable compensation and filling of the boundary point data blind area of ​​the coal quality point cloud in the coal preparation plant silo, improving the comprehensiveness and accuracy of the coal quality point cloud data.

[0077] Thirdly, this application provides an electronic device that adopts the following technical solution:

[0078] An electronic device includes a processor coupled to a memory;

[0079] The memory stores a computer program that can be loaded by a processor and executed as described in any of the first aspects regarding the coal quality point cloud boundary point data processing method for coal preparation plant silos.

[0080] Fourthly, this application provides a computer-readable storage medium, which adopts the following technical solution:

[0081] A computer-readable storage medium storing a computer program capable of being loaded by a processor and executing the coal quality point cloud boundary point data processing method for coal preparation plant silos as described in any of the first aspects. Attached Figure Description

[0082] Figure 1 This is a flowchart illustrating a method for processing boundary point data of coal quality point cloud in a coal preparation plant silo, as provided in an embodiment of this application.

[0083] Figure 2 This is a structural block diagram of a coal quality point cloud boundary point data processing device for a coal preparation plant silo, provided in an embodiment of this application.

[0084] Figure 3 This is a structural block diagram of the electronic device provided in the embodiments of this application. Detailed Implementation

[0085] The present application will be further described in detail below with reference to the accompanying drawings.

[0086] This application provides a method for processing boundary point data of coal quality point cloud in a coal preparation plant. This method can be executed by an electronic device, which can be a server or a terminal device. The server can be a standalone physical server, a server cluster or distributed system composed of multiple physical servers, or a cloud server providing cloud computing services. The terminal device can be a smartphone, tablet, desktop computer, etc., but is not limited to these.

[0087] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0088] Furthermore, the term "and / or" in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article, unless otherwise specified, generally indicates that the preceding and following related objects have an "or" relationship.

[0089] like Figure 1As shown, a method for processing boundary point data of coal quality point cloud in coal preparation plant silos is described in the following main process flow (steps S101 to S109):

[0090] Step S101: Obtain the original point set.

[0091] 3D millimeter-wave radar level gauges are characterized by high precision and strong anti-interference capabilities. They can accurately collect point cloud data of coal quality in coal preparation plant silos. By collecting 3D point cloud data (i.e., original points) of coal quality in silos through 3D millimeter-wave radar level gauges, all original points are combined into an original point set.

[0092] Step S102: Calculate the normal direction of each original point in the original point set.

[0093] Specifically, calculating the normal direction of each original point in the original point set includes: traversing each original point in the original point set and sequentially determining the normal direction of the first current original point, where the first current original point is the currently traversed original point; determining the normal direction of the first current original point includes: calculating the first distance between the first current original point and each original point in the original point set; sorting each original point according to the first distance in ascending order, and determining the first preset number of original points in the sorted list as neighboring points; calculating the covariance matrix based on the first current original point and neighboring points; performing eigenvalue decomposition on the covariance matrix to determine multiple eigenvalues ​​and the eigenvector corresponding to each eigenvalue; and determining the direction of the eigenvector corresponding to the smallest eigenvalue as the normal direction of the first current original point.

[0094] In this embodiment, each original point in the original point set is traversed, and the normal direction of each original point is determined sequentially. When determining the normal direction of the first current original point, the neighboring points of the first current original point are determined sequentially from smallest to largest based on the first distance between the first current original point and each original point in the original point set (excluding the first current original point). The number of neighboring points is a first preset number (preset, for example: 20). Then, the center position of the first current original point and all neighboring points is calculated, and the covariance matrix of the first current original point is calculated based on the center position. Then, the covariance matrix is ​​eigenvalued to determine multiple eigenvalues ​​and the eigenvectors corresponding to each eigenvalue. Finally, the direction of the eigenvector corresponding to the smallest eigenvalue is determined as the normal direction of the first current original point. The calculation methods of the covariance matrix and eigenvalue decomposition are conventional methods in the art and will not be described in detail here.

[0095] Step S103: Determine the first boundary point based on the normal direction, the distance between each original point, and the preset point spacing.

[0096] It is worth noting that the distance between any two adjacent original points in the original point set is the same, and the preset point spacing is the distance between any two adjacent original points.

[0097] Specifically, determining the first boundary point based on the normal direction, the distance between each original point, and the preset point spacing includes: traversing each original point in the original point set, sequentially determining whether the second current original point is the first boundary point, where the second current original point is the currently traversed original point; determining whether the second current original point is the first boundary point includes: determining the neighbor points of the second current original point based on the preset point spacing and the second distance between the second current original point and each original point in the original point set; if there exists a neighbor point whose normal direction is greater than the normal direction of the second current original point, then the second current original point is determined to be the first boundary point; if there exists no neighbor point whose normal direction is greater than the normal direction of the second current original point, then the second current original point and its neighbor points are projected onto the xy plane, and the direction vector between the second current original point and each neighbor point on the xy plane is determined, where the direction vector is the vector pointing from the second current original point to the neighbor point; if there exists an adjacent direction vector whose angle is greater than the second preset angle, then the second current original point is determined to be the first boundary point.

[0098] In this embodiment, the neighboring points of the second current original point are first determined: the search distance is calculated based on the preset point spacing, the search distance = preset distance multiple (e.g., 3.5) × preset point spacing, and the original points whose second distance from the second current original point is less than the search distance are determined as the neighboring points of the second current original point. That is, the neighboring points of the second current original point are the original points within the range of the second current original point as the center and the search distance as the radius.

[0099] Then, iterate through all neighboring points of the second current origin point. If the angle between the normal direction of a neighboring point and the normal direction of the second current origin point is greater than a first preset angle (e.g., 120°), then the second current origin point is determined to be the first boundary point. If the angle between the normal direction of all neighboring points and the normal direction of the second current origin point is less than or equal to the first preset angle, then project the second current origin point and each neighboring point onto the xy plane. On the xy plane, a direction vector pointing to the neighboring point is formed between each neighboring point and the second current origin point. Iterate through the direction vectors corresponding to each neighboring point in a clockwise order. If the angle between adjacent direction vectors is greater than the second preset angle (e.g., 90°), then the second current origin point is determined to be the first boundary point. If the angle between the normal direction of all neighboring points and the normal direction of the second current origin point is less than or equal to the first preset angle, and the angle between adjacent direction vectors after projection onto the xy plane is less than or equal to the second preset angle, then the second current origin point is determined not to be the first boundary point.

[0100] Step S104: Determine the second boundary point based on the normal direction of each original point in the first point set, the distance between each original point, and the preset point spacing.

[0101] The first point set is the original point set minus the first boundary point.

[0102] The method for determining the second boundary point is the same as the method for determining the first boundary point (which will not be repeated here). The difference lies in the point set used. When determining the first boundary point, the original point set consisting of all the original points is used; when determining the second boundary point, the original point set excluding the first boundary point is used.

[0103] Step S105: Fit the xy plane coordinates of the first boundary point using the linear least squares method and the standard equation of the circle, calculate the standard equation parameter values ​​of the circle, and calculate the center coordinates of the circle based on the standard equation parameter values.

[0104] The standard equation of a circle is: x*x+y*y+D*x+E*y+F=0. Substituting the x and y coordinates of all the first boundary points into the standard equation of the circle, and fitting the equation using the linear least squares method, we can calculate the values ​​of parameters D, E, and F. The coordinates of the center of the circle are (cx, cy) = (−D / 2, −E / 2).

[0105] Step S106: Project and scale the first boundary point based on the preset method and the center coordinates to determine the projection point.

[0106] Specifically, the projection and scaling of the first boundary point based on a preset method and the center coordinates are used to determine the projection point, including: obtaining the silo radius; traversing the first boundary points and sequentially determining the projection point corresponding to the current first boundary point, where the current first boundary point is the first boundary point being traversed; determining the projection point corresponding to the current first boundary point includes: calculating the azimuth angle of the current first boundary point relative to the center coordinates based on the x and y coordinates of the current first boundary point; calculating the first projection point based on the azimuth angle and the silo radius, where the first projection point is a two-dimensional coordinate in the xy plane; and calculating the projection point based on the silo radius, the Euclidean distance formula, and the x-coordinate of the current first boundary point. The scaling factor of the current first boundary point is calculated using the x and y coordinates. Based on the scaling factor, the x and y coordinates of the current first boundary point, a second projection point is calculated, where the second projection point is a two-dimensional coordinate in the xy plane. A first arithmetic sum of squares of the x and y coordinates of the first projection point is calculated. A second arithmetic sum of squares of the x and y coordinates of the second projection point is calculated. If the first arithmetic sum of squares is greater than or equal to the second arithmetic sum of squares, the projection point is determined based on the z coordinate of the second projection point and the current first boundary point. If the first arithmetic sum of squares is less than the second arithmetic sum of squares, the projection point is determined based on the z coordinate of the first projection point and the current first boundary point.

[0107] In this embodiment, by projecting and scaling the first boundary point, the projection point at the junction of the coal surface and the silo wall is obtained, thereby supplementing the point cloud data of the blind area. Each first boundary point corresponds to a projection point.

[0108] The azimuth angle theta of the current first boundary point relative to the center coordinates (cx, cy) is theta = arctan2(y1-cy, x1-cx). The coordinates of the first projection point are (X1_scale, Y1_scale), X1_scale = R*cos(theta), Y1_scale = R*sin(theta), where R is the radius of the silo, x1 is the x-coordinate of the current first boundary point, and y1 is the y-coordinate of the current first boundary point.

[0109] The scaling factor corresponding to the current first boundary point is factor=R / sqrt((x1*x1)+(y1*y1)), and the coordinates of the second projection point are (X2_scale, Y2_scale), X2_scale=factor*x1, Y2_scale=factor*y1, where R is the radius of the silo, x1 is the x-coordinate of the current first boundary point, and y1 is the y-coordinate of the current first boundary point.

[0110] The first arithmetic sum of the x and y coordinates of the first projection point is equal to X1_scale * X1_scale + Y1_scale * Y1_scale, and the second arithmetic sum of the x and y coordinates of the second projection point is equal to X2_scale * X2_scale + Y2_scale * Y2_scale. If the first arithmetic sum of squares is greater than or equal to the second arithmetic sum of squares, the coordinates of the projection point are (X2_scale, Y2_scale, z1); if the first arithmetic sum of squares is less than the second arithmetic sum of squares, the coordinates of the projection point are (X1_scale, Y1_scale, z1), where z1 is the z-coordinate of the current first boundary point.

[0111] It is worth noting that the above method for determining the projection point is applicable to all silos with a circular cross-section.

[0112] Step S107: Determine the interpolation point based on the projection point, the first boundary point, and the preset point spacing.

[0113] Specifically, determining interpolation points based on projection points, first boundary points, and preset point spacing includes: calculating a third distance between the first boundary point and the corresponding projection point; if the third distance is greater than a fourth distance, inserting interpolation points on the line connecting the first boundary point and the corresponding projection point based on the preset point spacing, where the fourth distance is a preset point spacing multiple of the preset point spacing; inserting interpolation points on the line connecting the first boundary point and the corresponding projection point based on the preset point spacing includes: generating an interpolation point on the line starting from the first boundary point at every preset point spacing until the distance between the newly generated interpolation point and the projection point is less than or equal to the preset point spacing.

[0114] Since the distance between the projection point and the first boundary point is large, in order to reduce the difficulty of subsequent surface reconstruction based on the point cloud data, it is necessary to insert an interpolation point between the first boundary point and the projection point.

[0115] In this embodiment, it is first determined whether an interpolation point needs to be inserted between the first boundary point and the corresponding projection point based on the third distance between them. If the third distance is less than or equal to the fourth distance, no interpolation point needs to be inserted between the first boundary point and the corresponding projection point. If the third distance is greater than the fourth distance, an interpolation point needs to be inserted on the line connecting the first boundary point and the corresponding projection point. The fourth distance is a preset point spacing of a preset multiple (e.g., 1.5). The interpolation point is generated as follows: starting from the first boundary point, an interpolation point is generated every preset point spacing on the line connecting the first boundary point and the corresponding projection point until the distance between the newly generated interpolation point and the projection point is less than or equal to the preset point spacing.

[0116] Step S108: Correct the z-values ​​of the projection points and interpolation points based on the first boundary point and the second boundary point.

[0117] The z-values ​​of the interpolation points and projection points are the same as those of the corresponding first boundary points. In order to improve the accuracy of the interpolation points and projection points, it is necessary to correct and compensate the z-values ​​of the projection points and interpolation points.

[0118] Specifically, the z-values ​​of the projection points and interpolation points are corrected based on the first boundary point and the second boundary point, including: constructing a z-value correction equation; substituting the three-dimensional coordinates of the first boundary point and the second boundary point into the z-value correction equation to calculate the z-values ​​of the projection points and interpolation points.

[0119] In this embodiment, z-value correction adopts a group correction method. A first boundary point, the corresponding interpolation point and projection point, and the second boundary point closest to the first boundary point are defined as a combination. The z-values ​​of the interpolation point and projection point within the combination are corrected by the first and second boundary points within the combination. For a combination, assuming the three-dimensional coordinates of the first boundary point are (x1, y1, z1), the three-dimensional coordinates of the second boundary point are (x2, y2, z2), and the three-dimensional coordinates of the interpolation point or projection point are (x3, y3, z3), the z-value correction equation is constructed as follows: Substituting the three-dimensional coordinates of the first boundary point, the three-dimensional coordinates of the second boundary point, and the xy-plane coordinates of the interpolation point into the z-value correction equation, we obtain the z-value of the interpolation point. Substituting the three-dimensional coordinates of the first boundary point, the three-dimensional coordinates of the second boundary point, and the xy-plane coordinates of the projection point into the z-value correction equation, we obtain the z-value of the projection point.

[0120] Step S109: Determine the target point set based on the original point set, the corrected projection points, and the corrected interpolation points.

[0121] Specifically, determining the target point set based on the original point set, the corrected projected points, and the corrected interpolated points includes: adding the corrected projected points and the corrected interpolated points to the original point set to generate the target point set; determining the first neighboring point corresponding to the corrected projected point based on the distance between every two points in the target point set and a second preset number; if the distance between the first neighboring point and the projected point is less than a preset distance and the first neighboring point is a corrected interpolated point, then removing the first neighboring point from the target point set; determining the second neighboring point corresponding to the second boundary point based on the distance between every two points in the target point set and a third preset number; if the distance between the second neighboring point and the second boundary point is less than a preset distance and the second neighboring point is a corrected interpolated point, then removing the second neighboring point from the target point set.

[0122] In this embodiment, corrected projection points and corrected interpolation points are added to the original point set to generate a target point set. Since the distance between the newly generated interpolation points and the projection points or the second boundary points may be small, to maintain the stability of the spacing between points, it is necessary to remove interpolation points that are close to the projection points or the second boundary points: The points in the target point set closest to the corrected projection points (a second preset number, which can be 4) are determined as the first neighboring points corresponding to the corrected projection points. If the distance between the first neighboring point and the corrected projection point is less than a preset distance (which can be 0.1m) and the first neighboring point is a corrected interpolation point, then the first neighboring point is removed from the target point set. The points in the target point set closest to the second boundary points (a third preset number, which can be 5) are determined as the second neighboring points corresponding to the second boundary points. If the distance between the second neighboring point and the second boundary point is less than a preset distance and the second neighboring point is a corrected interpolation point, then the second neighboring point is removed from the target point set. After removing the interpolation points close to the corrected projection points and the second boundary points, the final target point set is obtained.

[0123] After determining the final target point set, in order to facilitate subsequent surface reconstruction, it is necessary to re-estimate the normal vector of each point. The method for determining the normal vector of each point is the same as step S102 above, and will not be repeated here.

[0124] Figure 2 This is a structural block diagram of a coal quality point cloud boundary point data processing device 200 provided in an embodiment of this application.

[0125] like Figure 2 As shown, the coal quality point cloud boundary point data processing device 200 in the coal preparation plant mainly includes:

[0126] The original point set acquisition module 201 is used to acquire the original point set, which is based on the data collected by the 3D millimeter-wave radar level gauge.

[0127] The normal direction determination module 202 is used to calculate the normal direction of each original point in the original point set.

[0128] The first boundary point determination module 203 is used to determine the first boundary point based on the normal direction, the distance between each original point and the preset point spacing.

[0129] The second boundary point determination module 204 is used to determine the second boundary point based on the normal direction of each original point in the first point set, the distance between each original point, and the preset point spacing. The first point set is the point set after removing the first boundary point from the original point set.

[0130] The circle center coordinate determination module 205 is used to fit the xy plane coordinates of the first boundary point using the linear least squares method and the standard equation of the circle, calculate the standard equation parameter values ​​of the circle, and calculate the circle center coordinates based on the standard equation parameter values.

[0131] The projection point determination module 206 is used to project and scale the first boundary point based on a preset method and the center coordinates of the circle to determine the projection point.

[0132] The interpolation point determination module 207 is used to determine the interpolation point based on the projection point, the first boundary point, and the preset point spacing.

[0133] z-value correction module 208 is used to correct the z-values ​​of the projection points and interpolation points based on the first boundary point and the second boundary point.

[0134] The target point set determination module 209 is used to determine the target point set based on the original point set, the corrected projection points, and the corrected interpolation points.

[0135] As an optional implementation of this embodiment, the normal direction determination module 202 is specifically used to calculate the normal direction of each original point in the original point set, including: traversing each original point in the original point set, and sequentially determining the normal direction of the first current original point, where the first current original point is the currently traversed original point; determining the normal direction of the first current original point includes: calculating the first distance between the first current original point and each original point in the original point set; sorting each original point according to the first distance from smallest to largest, and determining the first preset number of original points in the sort as neighboring points; calculating the covariance matrix based on the first current original point and neighboring points; performing eigenvalue decomposition on the covariance matrix to determine multiple eigenvalues ​​and the eigenvector corresponding to each eigenvalue; and determining the direction of the eigenvector corresponding to the smallest eigenvalue as the normal direction of the first current original point.

[0136] As an optional implementation of this embodiment, the first boundary point determination module 203 is specifically used to determine the first boundary point based on the normal direction, the distance between each original point, and the preset point spacing, including: traversing each original point in the original point set, and sequentially determining whether the second current original point is the first boundary point, wherein the second current original point is the currently traversed original point; determining whether the second current original point is the first boundary point includes: determining the neighbor points of the second current original point based on the preset point spacing and the second distance between the second current original point and each original point in the original point set; if there is a neighbor point whose normal direction is greater than the normal direction of the second current original point, the angle between the normal direction of the neighbor point and the normal direction of the second current original point is greater than the first preset angle, then determining the second current original point as the first boundary point; if there is no neighbor point whose normal direction is greater than the normal direction of the second current original point, the angle between the normal direction of the neighbor point and the normal direction of the second current original point is greater than the first preset angle, then projecting the second current original point and the neighbor points onto the xy plane, and determining the direction vector between the second current original point and each neighbor point on the xy plane, wherein the direction vector is the vector pointing from the second current original point to the neighbor point; if there is an adjacent direction vector whose angle is greater than the second preset angle, then determining the second current original point as the first boundary point.

[0137] As an optional implementation of this embodiment, the projection point determination module 206 is specifically used to project and scale the first boundary point based on a preset method and the center coordinates to determine the projection point, including: obtaining the silo radius; traversing the first boundary points and sequentially determining the projection point corresponding to the current first boundary point, wherein the current first boundary point is the currently traversed first boundary point; determining the projection point corresponding to the current first boundary point includes: calculating the azimuth angle of the current first boundary point relative to the center coordinates based on the x and y coordinates of the current first boundary point; calculating the first projection point based on the azimuth angle and the silo radius, wherein the first projection point is a two-dimensional coordinate in the xy plane; and calculating the first projection point based on the silo radius and Euclidean distance. The scaling factor of the current first boundary point is calculated using the formula, the x-coordinate, and the y-coordinate of the current first boundary point. Based on the scaling factor, the x-coordinate, and the y-coordinate of the current first boundary point, a second projection point is calculated, where the second projection point is a two-dimensional coordinate in the xy-plane. The first arithmetic sum of squares of the x-coordinate and y-coordinate of the first projection point is calculated. The second arithmetic sum of squares of the x-coordinate and y-coordinate of the second projection point is calculated. If the first arithmetic sum of squares is greater than or equal to the second arithmetic sum of squares, the projection point is determined based on the z-coordinate of the second projection point and the current first boundary point. If the first arithmetic sum of squares is less than the second arithmetic sum of squares, the projection point is determined based on the z-coordinate of the first projection point and the current first boundary point.

[0138] As an optional implementation of this embodiment, the interpolation point determination module 207 is specifically used to determine interpolation points based on the projection point, the first boundary point, and the preset point spacing, including: calculating the third distance between the first boundary point and the corresponding projection point; if the third distance is greater than the fourth distance, inserting an interpolation point on the line connecting the first boundary point and the corresponding projection point based on the preset point spacing, wherein the fourth distance is a preset point spacing multiple thereof; inserting an interpolation point on the line connecting the first boundary point and the corresponding projection point based on the preset point spacing includes: generating an interpolation point on the line starting from the first boundary point at every preset point spacing until the distance between the newly generated interpolation point and the projection point is less than or equal to the preset point spacing.

[0139] As an optional implementation of this embodiment, the z-value correction module 208 is specifically used to correct the z-values ​​of the projection point and the interpolation point based on the first boundary point and the second boundary point, including: constructing a z-value correction equation; substituting the three-dimensional coordinates of the first boundary point and the second boundary point into the z-value correction equation, and calculating the z-values ​​of the projection point and the interpolation point.

[0140] As an optional implementation of this embodiment, the target point set determination module 209 is specifically used to determine a target point set based on the original point set, the corrected projection points, and the corrected interpolation points, including: adding the corrected projection points and the corrected interpolation points to the original point set to generate a target point set; determining a first neighboring point corresponding to the corrected projection point based on the distance between every two points in the target point set and a second preset number; if the distance between the first neighboring point and the projection point is less than a preset distance and the first neighboring point is a corrected interpolation point, then removing the first neighboring point from the target point set; determining a second neighboring point corresponding to the second boundary point based on the distance between every two points in the target point set and a third preset number; if the distance between the second neighboring point and the second boundary point is less than a preset distance and the second neighboring point is a corrected interpolation point, then removing the second neighboring point from the target point set.

[0141] In one example, the module in any of the above devices may be one or more integrated circuits configured to implement the above methods, such as one or more application-specific integrated circuits (ASICs), or one or more digital signal processors (DSPs), or one or more field-programmable gate arrays (FPGAs), or a combination of at least two of these integrated circuit forms.

[0142] For example, when modules in a device can be implemented via a processing element scheduler, the processing element can be a general-purpose processor, such as a central processing unit (CPU) or other processor capable of calling programs. Alternatively, these modules can be integrated together to form a system-on-a-chip (SOC).

[0143] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the above-described device and module can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0144] Figure 3 This is a structural block diagram of an electronic device 300 provided in an embodiment of this application.

[0145] like Figure 3 As shown, the electronic device 300 includes a processor 301 and a memory 302, and may further include one or more of an information input / output (I / O) interface 303, a communication component 304, and a communication bus 305.

[0146] The processor 301 controls the overall operation of the electronic device 300 to complete all or part of the steps of the above-described method for processing boundary point data of coal quality point cloud in coal preparation plant silos. The memory 302 stores various types of data to support the operation of the electronic device 300. This data may include, for example, instructions for any application or method operating on the electronic device 300, as well as application-related data. The memory 302 can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as one or more of the following: Static Random Access Memory (SRAM), Electrically Erasable Programmable Read-Only Memory (EEPROM), Erasable Programmable Read-Only Memory (EPROM), Programmable Read-Only Memory (PROM), Read-Only Memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk.

[0147] I / O interface 303 provides an interface between processor 301 and other interface modules, such as keyboards, mice, and buttons. These buttons can be virtual or physical. Communication component 304 is used for wired or wireless communication between electronic device 300 and other devices. Wireless communication includes Wi-Fi, Bluetooth, Near Field Communication (NFC), 2G, 3G, or 4G, or a combination thereof. Therefore, the corresponding communication component 304 may include a Wi-Fi component, a Bluetooth component, and an NFC component.

[0148] The electronic device 300 can be implemented by one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), controllers, microcontrollers, microprocessors, or other electronic components to execute the coal quality point cloud boundary point data processing method for coal preparation plant silos given in the above embodiments.

[0149] The communication bus 305 may include a path for transmitting information between the aforementioned components. The communication bus 305 may be a PCI (Peripheral Component Interconnect) bus or an EISA (Extended Industry Standard Architecture) bus, etc. The communication bus 305 may be divided into an address bus, a data bus, a control bus, etc.

[0150] Electronic device 300 may include, but is not limited to, mobile terminals such as mobile phones, laptops, digital radio receivers, PDAs (personal digital assistants), PADs (tablet computers), PMPs (portable multimedia players), and in-vehicle terminals (such as in-vehicle navigation terminals), as well as fixed terminals such as digital TVs and desktop computers, and may also be servers.

[0151] This application also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the above-described method for processing boundary point data of coal quality point cloud in coal preparation plant silos.

[0152] The computer-readable storage medium may include various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0153] The terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0154] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the foregoing application concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions claimed in this application.

Claims

1. A coal quality point cloud boundary point data processing method for a coal preparation plant bunker, characterized in that, include: Obtain the original point set, which is based on data collected by a 3D millimeter-wave radar level gauge; Calculate the normal direction of each original point in the set of original points; The first boundary point is determined based on the normal direction, the distance between each of the original points, and the preset point spacing. The second boundary point is determined based on the normal direction of each original point in the first point set, the distance between each original point, and the preset point spacing. The first point set is the point set after removing the first boundary point from the original point set. The xy-plane coordinates of the first boundary point are fitted using the linear least squares method and the standard equation of a circle, the standard equation parameter values ​​of the circle are calculated, and the center coordinates of the circle are calculated based on the standard equation parameter values. Based on a preset method and the center coordinates of the circle, the first boundary point is projected and scaled to determine the projection point; The interpolation point is determined based on the projection point, the first boundary point, and the preset point spacing. Correct the z-values ​​of the projection point and the interpolation point based on the first boundary point and the second boundary point; The target point set is determined based on the original point set, the corrected projection points, and the corrected interpolation points.

2. The method according to claim 1, characterized in that, The calculation of the normal direction of each original point in the original point set includes: Traverse each of the original points in the set of original points, and determine the normal direction of the first current original point in turn, wherein the first current original point is the original point being traversed. Determining the normal direction of the first current origin point includes: Calculate the first distance between the first current origin point and each of the origin points in the set of origin points; The original points are sorted in ascending order according to the first distance, and the first preset number of original points in the sort are determined as neighboring points; Calculate the covariance matrix based on the first current original point and the neighboring points; The covariance matrix is ​​subjected to eigenvalue decomposition to determine multiple eigenvalues ​​and the eigenvector corresponding to each eigenvalue; The direction of the eigenvector corresponding to the smallest eigenvalue is determined as the normal direction of the first current original point.

3. The method according to claim 1, characterized in that, The determination of the first boundary point based on the normal direction, the distance between each of the original points, and the preset point spacing includes: Traverse each of the original points in the set of original points, and determine in turn whether the second current original point is the first boundary point. The second current original point is the original point being traversed. The step of determining whether the second current original point is the first boundary point includes: Based on the preset point spacing and the second distance between the second current original point and each of the original points in the set of original points, the neighbor points of the second current original point are determined; If the angle between the normal direction of a neighboring point and the normal direction of the second current origin point is greater than a first preset angle, then the second current origin point is determined to be the first boundary point; If there is no neighboring point whose normal direction is greater than the angle between the normal direction of the second current origin point and the normal direction of the second current origin point, then the second current origin point and the neighboring point are projected onto the xy plane, and the direction vector between the second current origin point and each neighboring point on the xy plane is determined. The direction vector is a vector pointing from the second current origin point to the neighboring point. If there exists an angle between adjacent direction vectors that is greater than a second preset angle, then the second current original point is determined to be the first boundary point.

4. The method according to claim 1, characterized in that, The step of projecting and scaling the first boundary point based on a preset method and the center coordinates of the circle to determine the projection point includes: Obtain the radius of the silo; Traverse the first boundary point and determine the projection point corresponding to the current first boundary point in turn. The current first boundary point is the first boundary point traversed in the current iteration. Determining the projection point corresponding to the current first boundary point includes: Calculate the azimuth angle of the current first boundary point relative to the center coordinates based on the x and y coordinates of the current first boundary point; The first projection point is calculated based on the azimuth angle and the radius of the silo, and the first projection point is a two-dimensional coordinate in the xy plane; The scaling factor of the current first boundary point is calculated based on the silo radius, the Euclidean distance formula, the x-coordinate and y-coordinate of the current first boundary point. The second projection point is calculated based on the scaling factor, the x-coordinate and y-coordinate of the current first boundary point, and the second projection point is a two-dimensional coordinate in the xy plane; Calculate the first arithmetic sum of the squares of the x and y coordinates of the first projection point; Calculate the second arithmetic sum of the squares of the x and y coordinates of the second projection point; If the first arithmetic sum of squares is greater than or equal to the second arithmetic sum of squares, then the projection point is determined based on the second projection point and the z-coordinate of the current first boundary point; If the first arithmetic sum of squares is less than the second arithmetic sum of squares, then the projection point is determined based on the first projection point and the z-coordinate of the current first boundary point.

5. The method according to claim 1, characterized in that, The step of determining the interpolation point based on the projection point, the first boundary point, and the preset point spacing includes: Calculate the third distance between the first boundary point and the corresponding projection point; If the third distance is greater than the fourth distance, then an interpolation point is inserted on the line connecting the first boundary point and the corresponding projection point based on the preset point spacing, wherein the fourth distance is a preset multiple of the preset point spacing; The step of inserting interpolation points on the line connecting the first boundary point and the corresponding projection point based on the preset point spacing includes: Starting from the first boundary point on the connecting line, an interpolation point is generated at every preset point spacing until the distance between the newly generated interpolation point and the projection point is less than or equal to the preset point spacing.

6. The method according to claim 1, characterized in that, The step of correcting the z-values ​​of the projection point and the interpolation point based on the first boundary point and the second boundary point includes: Construct the z-value correction equation; Substitute the three-dimensional coordinates of the first boundary point and the second boundary point into the z-value correction equation to calculate the z-values ​​of the projection point and the interpolation point.

7. The method according to claim 1, characterized in that, Determining the target point set based on the original point set, the corrected projected points, and the corrected interpolated points includes: The corrected projection points and the corrected interpolation points are added to the original point set to generate the target point set; The first neighboring point corresponding to the corrected projection point is determined based on the distance between every two points in the target point set and the second preset number. If the distance between the first neighboring point and the projected point is less than a preset distance and the first neighboring point is the corrected interpolation point, then the first neighboring point is removed from the target point set. The second neighboring point corresponding to the second boundary point is determined based on the distance between every two points in the target point set and the third preset number. If the distance between the second neighboring point and the second boundary point is less than a preset distance and the second neighboring point is the corrected interpolation point, then the second neighboring point is removed from the target point set.

8. A data processing device for boundary points of coal quality point cloud in a coal preparation plant silo, characterized in that, include: The original point set acquisition module is used to acquire the original point set, which is based on the data collected by the 3D millimeter-wave radar level gauge. The normal direction determination module is used to calculate the normal direction of each original point in the original point set. The first boundary point determination module is used to determine the first boundary point based on the normal direction, the distance between each of the original points and the preset point spacing. The second boundary point determination module is used to determine the second boundary point based on the normal direction of each original point in the first point set, the distance between each original point, and the preset point spacing. The first point set is the point set after removing the first boundary point from the original point set. The circle center coordinate determination module is used to fit the xy plane coordinates of the first boundary point using the linear least squares method and the standard equation of the circle, calculate the standard equation parameter values ​​of the circle, and calculate the circle center coordinates based on the standard equation parameter values. The projection point determination module is used to project and scale the first boundary point based on a preset method and the center coordinates of the circle to determine the projection point. An interpolation point determination module is used to determine an interpolation point based on the projection point, the first boundary point, and the preset point spacing. The z-value correction module is used to correct the z-values ​​of the projection point and the interpolation point based on the first boundary point and the second boundary point. The target point set determination module is used to determine the target point set based on the original point set, the corrected projection points, and the corrected interpolation points.

9. An electronic device, characterized in that, Includes a processor, which is coupled to a memory; The processor is configured to execute a computer program stored in the memory to cause the electronic device to perform the method as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, It includes a computer program or instructions that, when run on a computer, cause the computer to perform the method as described in any one of claims 1 to 7.

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