Working face straightness evaluation method based on all-pose hyper-temporal-spatial transformation

Abstract

The invention discloses a working face straightness evaluation method based on all-pose hyper-temporal-spatial transformation, and relates to the technical field of coal mining control, and the method comprises the steps: obtaining working face equipment and coal seam information, including a hydraulic support point cloud, a coal mining machine pose and a scraper conveyor track; a three-machine virtual model is constructed by utilizing a digital twinning technology, and a coal seam datum plane is established by adopting a coal seam transparentizing and datum plane obtaining method. A three-point circle setting method is adopted to calculate the circle center of a circumcircle and a normal vector for attitude curve fitting, support point cloud information of the hydraulic support group is mapped to a coal seam datum plane through hyper-temporal-spatial transformation, and a space baseline of the hydraulic support group is calculated. And the spatial straightness of the hydraulic support and the scraper conveyor is evaluated, a working face overall spatial straightness evaluation model is established in combination with the floating connection error, the upward-sliding and downward-sliding error and the cutting track error, and the overall spatial straightness is obtained. According to the method, the working face straightness can be evaluated more accurately.

Description

Technical Field

[0001] This application relates to the technical field of coal mining control, and particularly to a method for evaluating the straightness of a working face based on full pose and super-time-space transformation. Background Art

[0002] In the management of fully mechanized mining faces, the principle of "three straights and one flat" is of crucial importance. This principle emphasizes that hydraulic supports, scraper conveyors, and coal walls should all be arranged in a straight line to ensure the overall flatness of the working face. To achieve this goal, the evaluation of straightness is extremely critical. As the core link of the straightening work, the accuracy of the straightness evaluation of the fully mechanized mining face not only affects the cutting efficiency and quality of the shearer, but also affects the support efficiency of the hydraulic supports and the advancing rate of the entire working face. Summary of the Invention

[0003] The purpose of this application is to provide a method for evaluating the straightness of a working face based on full pose and super-time-space transformation, which can more accurately evaluate the straightness of the working face.

[0004] To achieve the above purpose, this application provides the following solutions:

[0005] In the first aspect, this application provides a method for evaluating the straightness of a working face based on full pose and super-time-space transformation, including:

[0006] Obtain the equipment information and coal seam information at the working face; the equipment information includes the support point cloud information of the hydraulic support group in the shearer, the pose data of the shearer, and the actual trajectory of the scraper conveyor; the actual trajectory of the scraper conveyor is inversely obtained based on the pose data of the shearer and the spatial position relationship between the scraper conveyor and the shearer;

[0007] Based on the support point cloud information of the hydraulic support group, the pose data of the shearer, and the actual trajectory of the scraper conveyor, construct a three-machine virtual model based on digital twin technology; the three-machine equipment virtual model includes a hydraulic support virtual model, a scraper conveyor virtual model, and a shearer virtual model;

[0008] Based on the coal seam information and the three-machine virtual model, construct a coal seam reference plane based on the coal seam transparency modeling method, the segmented plane fitting method, and the reference plane acquisition method;

[0009] Based on the support point cloud information of the hydraulic support group, use the three-point circle determination method to calculate the circumcenter and normal vector for attitude curve fitting, and map the support point cloud information of the hydraulic support group to the coal seam reference plane through super-time-space transformation, and calculate the spatial baseline of the hydraulic support group;

[0010] Evaluate the spatial straightness of the hydraulic support according to the sum of the distances from the measurement points on the actual axis to the spatial baseline of the hydraulic support group;

[0011] Evaluate the spatial straightness of the scraper conveyor based on the projection of the characteristic points of the scraper conveyor and the radius of the serpentine cylinder; the serpentine cylinder is a cylinder that can envelope all the characteristic points of the scraper conveyor.

[0012] According to the evaluation results of the spatial straightness of the hydraulic support and the evaluation results of the spatial straightness of the scraper conveyor, add the floating connection mechanism error, the up and down error, and the cutting trajectory error to establish an evaluation model for the overall spatial straightness of the working face, and obtain the overall spatial straightness of the working face.

[0013] According to the specific embodiments provided by the present application, the present application discloses the following technical effects:

[0014] The present application provides a method for evaluating the straightness of a working face based on full pose and super spacetime transformation. First, by obtaining the equipment information and coal seam information at the working face, it provides a detailed data basis for subsequent evaluation, ensuring the comprehensiveness and accuracy of the evaluation. Then, based on digital twin technology, a virtual model of the three machines is constructed, which can truly reflect the operating state and spatial relationship of the working face equipment. The virtual model helps to intuitively understand the interaction between the equipment. Then, by constructing a coal seam reference plane, it provides a unified reference for evaluation, eliminates the influence of coal seam unevenness on the evaluation results, and improves the accuracy and reliability of the evaluation. By mapping the point cloud information of the support of the hydraulic support group to the coal seam reference plane through super spacetime transformation and calculating the spatial baseline of the hydraulic support group, it can accurately reflect the position and posture of the hydraulic support group in space and accurately evaluate the spatial straightness of the hydraulic support. Based on the sum of the distances from the measuring points on the actual axis to the spatial baseline of the hydraulic support group, the spatial straightness of the hydraulic support is evaluated, which can intuitively reflect the straightness of the hydraulic support group. For the evaluation of the spatial straightness of the scraper conveyor, it is calculated based on the projection of the characteristic points of the scraper conveyor and the radius of the serpentine cylinder, considering the overall shape and the distribution of the characteristic points of the scraper conveyor, thereby improving the accuracy of the evaluation. Finally, comprehensively considering the evaluation results of the spatial straightness of the hydraulic support, the evaluation results of the spatial straightness of the scraper conveyor, and factors such as the floating connection mechanism error, the up and down error, and the cutting trajectory error, an evaluation model for the overall spatial straightness of the working face is established. This comprehensive evaluation method can more accurately reflect the straightness of the working face and provide strong guidance for production. Description of the Drawings

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0016] Figure 1 Flow chart of a working face straightness evaluation method based on full pose super spacetime transformation provided by an embodiment of the present application;

[0017] Figure 2 Working principle diagram of the working face space straightness evaluation method provided by an embodiment of the present application;

[0018] Figure 3 Working principle diagram of the virtual scene and hyperplane construction model provided by an embodiment of the present application;

[0019] Figure 4 Working principle diagram of the hydraulic support group straightness evaluation model provided by an embodiment of the present application;

[0020] Figure 5 Working principle diagram of the error factor evaluation model provided by an embodiment of the present application;

[0021] Figure 6 Schematic diagram of factors in the hydraulic support group straightness evaluation model provided by an embodiment of the present application;

[0022] Figure 7 Spatial relationship diagram of key points of the hydraulic support group straightness evaluation model provided by an embodiment of the present application. Detailed implementation manners

[0023] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0024] To make the above objects, features, and advantages of the present application more obvious and understandable, the present application will be further described in detail below in conjunction with the accompanying drawings and specific implementation manners.

[0025] Embodiment 1

[0026] As Figure 1 shown, this embodiment provides a working face straightness evaluation method based on full pose super spacetime transformation, including:

[0027] Step 101: Obtain the equipment information and coal seam information at the working face; the equipment information includes the support point cloud information of the hydraulic support group in the shearer, the pose data of the shearer, and the actual trajectory of the scraper conveyor; the actual trajectory of the scraper conveyor is inversely obtained based on the pose data of the shearer and the spatial position relationship between the scraper conveyor and the shearer;

[0028] Step 102: Based on the bracket point cloud information of the hydraulic support group, the pose data of the shearer, and the actual trajectory of the scraper conveyor, construct a virtual model of the three machines using digital twin technology; the virtual model of the three machines includes a virtual model of the hydraulic support, a virtual model of the scraper conveyor, and a virtual model of the shearer;

[0029] Step 103: Based on the coal seam information and the virtual model of the three machines, construct a coal seam reference plane using the coal seam transparency modeling method, the segmented plane fitting method, and the reference plane acquisition method;

[0030] Step 104: Based on the bracket point cloud information of the hydraulic support group, calculate the circumcenter and normal vector of the circumscribed circle using the three-point circle method for attitude curve fitting, and map the bracket point cloud information of the hydraulic support group to the coal seam reference plane through super-time and space transformation to calculate the spatial baseline of the hydraulic support group;

[0031] Step 105: Evaluate the spatial straightness of the hydraulic support based on the sum of the distances from the measurement points on the actual axis to the spatial baseline of the hydraulic support group;

[0032] Step 106: Evaluate the spatial straightness of the scraper conveyor based on the projection of the characteristic points of the scraper conveyor and the radius of the snake-shaped cylinder; the snake-shaped cylinder is a cylinder that can envelope all the characteristic points of the scraper conveyor;

[0033] Step 107: According to the evaluation results of the spatial straightness of the hydraulic support and the evaluation results of the spatial straightness of the scraper conveyor, add the floating connection mechanism error, the up and down running error, and the cutting trajectory error to establish an evaluation model for the overall spatial straightness of the working face, and obtain the overall spatial straightness of the working face.

[0034] Among them, in some embodiments, when performing step 101, as Figure 3 shown, it can be specifically as follows:

[0035] Step 111: Install a three-dimensional lidar system at the middle position of the shearer body;

[0036] Step 112: During the traction of the shearer, scan the hydraulic support group based on the three-dimensional lidar system, eliminate the noise points during the scanning process using a filtering method, and segment the point clouds that have nothing to do with the hydraulic support group to obtain the first point cloud information of the hydraulic support group;

[0037] Step 113: Install two-dimensional radars at the column parts of each hydraulic support in the hydraulic support group;

[0038] Step 114: Based on the two-dimensional radars, scan each hydraulic support to obtain the second point cloud information of the hydraulic support group.

[0039] Specifically, a three-dimensional lidar system is installed at the middle position of the shearer body. During the traction process of the shearer, it scans the hydraulic support group in real time. The filtering method is used to eliminate noise points and segment the irrelevant point clouds to obtain partial point cloud information of the hydraulic support group. For the analysis of the point cloud of the support group, uniform sampling filtering and conditional filtering applicable to noise removal are selected. When reducing the point cloud density, the overall shape and characteristics of the point cloud are maintained, and the point clouds that meet the conditions are screened out, so as to realize the extraction of the point cloud information of the support column part. The two-dimensional radar is installed at the column part of the hydraulic support for scanning, so as to obtain the point cloud information of the top beam, base, shield beam, etc., and thus supplement the point cloud information obtained by the three-dimensional point cloud.

[0040] Among them, the method for obtaining the actual trajectory of the scraper conveyor is as follows:

[0041] Step 121: Use the extended Kalman filter algorithm to correct the pose data of the shearer; the pose data includes the position and direction of the shearer.

[0042] Step 122: Use the filtering algorithm to correct the position and direction of the shearer.

[0043] Step 123: Based on the three-dimensional lidar installed on the shearer body, obtain the spatial position relationship between the shearer and the hydraulic support group.

[0044] Step 124: Based on the position of the shearer, use the spatial position relationship between the scraper conveyor and the shearer to invert the actual trajectory of the scraper conveyor.

[0045] Specifically, a strapdown inertial navigation system (INS) is installed on the shearer to provide the pose data of the shearer in real time, including the changes in its position and direction. The extended Kalman filter (EKF) algorithm is used to correct the collected pose data to eliminate the cumulative error. By combining the sensor data and the environmental model, the filtering algorithm is used to accurately correct the actual position and attitude of the shearer to ensure the accuracy of subsequent data processing.

[0046] Since the three-dimensional lidar installed on the shearer body is consistent with the running trajectory of the shearer, the relative relationship between the shearer and the hydraulic support group can be obtained from it. Based on the position information of the shearer, using the known spatial position relationship between the scraper conveyor and the shearer, the actual trajectory of the scraper conveyor is inverted.

[0047] In some embodiments, when performing step 102, it can be specifically as follows:

[0048] Through digital twin technology, the point cloud data of the hydraulic support group is mapped into the virtual space. In Unity3D, based on the concept of complementing the real with the virtual and reflecting the real with the virtual, the missing pose information of the hydraulic support is supplemented by using the method of fusing virtual and real data, and a complete virtual model of the hydraulic support is constructed, so as to realize the accurate reconstruction of the hydraulic support group. At the same time, the virtual models of the scraper conveyor and the shearer are constructed in real time in Unity3D. Through virtual reality and augmented reality technologies, based on the spatial position information of the shearer and the scraper conveyor and the relative relationship between the shearer and the hydraulic support, the accurate reconstruction of the virtual models of the three machines, namely the hydraulic support, the scraper conveyor, and the shearer, is realized.

[0049] Among them, in some embodiments, when performing step 103, as Figure 2 and Figure 3 shown, it can be specifically as follows:

[0050] When constructing the coal seam reference plane, first perform coal seam transparency modeling:

[0051] Through three-dimensional seismic exploration technology, obtain the formation reflection wave field information carrying the underground rock strata and geological structure characteristics, and form the first floor information;

[0052] Based on the first floor information, weighted fuse the shearer drum cutting information to obtain the second floor information; the shearer drum cutting information is the vibration signal and cutting force information generated when the drum cuts the coal seam during the coal mining process;

[0053] According to the second floor information, construct the "equipment - coal seam floor" coupling relationship in Unity3D, and introduce the Bayesian data assimilation algorithm to obtain the third floor information, and complete the coal seam transparency.

[0054] Then perform coal seam segmentation and segmented plane fitting:

[0055] When segmenting the coal seam, according to the known coal seam information, use Matlab to calculate the fitting polynomial, adopt the stepwise regression method to determine the optimal order, and start iterating from the quadratic polynomial: z(x,y) = a0 + a1x + a2y + a3x 2 + a4xy + a5y 2 , gradually increase the order so that the fitting surface can be as close as possible to the actually measured data points; use the diff function in Matlab to calculate the first-order partial derivative and second-order partial derivative of this polynomial function, set the partial derivative to 0, and solve this non-linear equation system to find the critical points; use the second-order partial derivative and its determinant to determine whether these points are local maxima, local minima, or saddle points, and the saddle points need to be eliminated; segment the surface according to the extreme points.

[0056] When performing piecewise plane fitting, the discrete point information on each segment is obtained, and the least squares method is used to fit the plane. A target function (error function) is defined, and this target function measures the distance from each data point to the fitted plane. For each point (x i , y i , z i ), the distance to the plane is: The goal of the least squares method is to minimize the sum of the squares of the distances from all these points to the plane, that is: n is the number of points; to find the minimum of the error function, take the derivatives of A, B, C, and D, and set the derivatives to zero to find A, B, C, and D in the linear equation Ax + By + Cz + D = 0:

[0057]

[0058] The normal vector (A, B, C) of Ax + By + Cz + D = 0 represents the direction of the fitted plane and can represent the normal vector of the piecewise surface; project the piecewise surface along the normal vector onto the fitted plane to make the plane and the surface projection completely coincide, thereby determining the size of the fitted surface.

[0059] Finally, take the average value of the normal vectors of each piecewise plane as the normal vector of the reference plane, give a random reference point, set this point as the initial position of the reference plane, convert the coordinates of each piecewise plane to the coordinate system of the reference plane, and then translate each piecewise plane so that they are spliced in sequence to construct the coal seam reference plane.

[0060] In some embodiments, when performing step 104, as Figure 2 and Figure 4 shown, specifically it can be as follows:

[0061] Obtain the position information of six key points, namely the base-column pin point, column-roof beam pin point, and front link-cover beam pin point, based on the known hydraulic support data. And the key points of the hydraulic support are named according to A 11 , A 12 , B 11 , B 12 , C 11 , C 12 ... C i1 , C i2 . The first digit of the subscript is the hydraulic support serial number, and there are a total of i hydraulic supports. The second digit is the serial number of this point on a single hydraulic support; as Figure 6 and Figure 7 shown, obtain the center positions O i1 , O i2 of the circumcircles of the two triangles formed by the six key points according to three points determining a circle; take the base-rear link pin point as the coordinate origin, and obtain the coordinates of the center O as: Solve the normal vector based on the feature circular surface. There should be two feature normal vectors on each hydraulic support, denoted as Taking the first hydraulic support as an example, connect A 11 , O 11 The feature vectors of the circular surface are:

[0062]

[0063]

[0064] Among them, a is the length of BC, b is the length of AC, c is the length of AB, H is the height of the hydraulic support, γ is the inclination angle of the shield beam, θ is the inclination angle of the rear connecting rod, η is the angle between AC and triangle ABC, η' is the angle between BC and triangle ABC, is the inclination angle between the connecting line of the front connecting rod pin shaft and the rear connecting rod pin shaft and the base, ε is the angle between the column and the base, L1 is the length of the connecting line of the front and rear connecting rod pin shafts on the shield beam, L3 is the length of the rear connecting rod, L4 is the length of the connecting line of the front and rear connecting rod pin shafts on the base, L5 is the horizontal distance between the base-column pin shaft and the base-front connecting rod pin shaft; Each hydraulic support performs curve fitting based on the feature normal vector to obtain a curve that can represent the internal attitude of the hydraulic support.

[0065] In some embodiments, when performing step 105, it can be specifically as follows:

[0066] The hydraulic support group performs a super-space-time transformation following the fitting plane corresponding to the segmented coal seam where it is located and moves to the corresponding position on the reference plane; Based on the above curve representing the internal attitude of the hydraulic support, spline fitting is performed in Matlab to obtain the space baseline of the hydraulic support group; Assume that the direction vector of the space baseline on the space X, Y, Z is (l, m, n), and the baseline lp passes through the fixed point (x o , y o , z o ), then the space straight line equation of lp is:

[0067]

[0068] Among them, x o is the average value of the x coordinate of the central axis of the feature cylinder of the intermediate support, y o is the average value of the y coordinate of the central axis of the feature cylinder of the intermediate support, z o is the average value of the z coordinate of the central axis of the feature cylinder of the intermediate support, and the direction vector is the normal vector of the feature cylinder surface; Establish a formula as the standard for evaluating the space straightness, and represent the sum of the distances from the measurement points on the actual axis to the reference axis to evaluate the space straightness of the hydraulic support.

[0069]

[0070] where (x ij , y ij , z ij ) are discrete points on the base of each support, where i represents the support serial number, j represents the number of characteristic circles on the support, and the smaller the f value, the better the straightness of the fully mechanized coal face; conversely, the worse the straightness.

[0071] In some embodiments, when performing step 106, specifically, it can be as follows:

[0072] Select the center of the pin ear clearance of each middle trough of the scraper conveyor as the characteristic point, project the scraper conveyor onto the coal seam floor, and obtain the position information of the projection points of the characteristic points on the floor;

[0073] According to the position information of the projection points, calculate the distance between the projection points and the fitting plane along the segmented normal vector direction;

[0074] According to the distance, move each characteristic point along the normal vector direction to obtain the moved position information; the moved position information is the position information of the middle trough after eliminating the influence of the coal seam floor;

[0075] After performing a spatio-temporal transformation on the moved middle trough and the fitting plane, construct a snake-shaped cylinder that can envelope all the characteristic points;

[0076] Evaluate the spatial straightness of the scraper conveyor according to the radius of the snake-shaped cylinder.

[0077] Specifically, select the center of the pin ear clearance of each middle trough as the characteristic point, project the scraper conveyor onto the coal seam floor, obtain the position information of the projection points of the characteristic points on the floor, calculate the distance between the projection points and the fitting plane along the segmented normal vector direction, move all the characteristic points along the normal vector direction according to this distance, and the obtained position is the position information of the middle trough after eliminating the influence of the coal seam floor; the moved middle trough follows the fitting plane corresponding to the segmented coal seam where it is located for spatio-temporal transformation and moves to the corresponding position on the reference plane; construct a snake-shaped cylinder that can envelope all the characteristic points, and the radius r of any cross-section of the cylinder is the same. Evaluate the straightness of the scraper conveyor based on the radius of this cylinder. The smaller the radius, the better the straightness.

[0078] In some embodiments, when performing step 107, as Figure 5 shown, specifically, it can be as follows:

[0079] Among them, the error evaluation of the floating connection mechanism is specifically:

[0080] Set up a three-dimensional Cartesian coordinate system (X, Y, Z), where the advancing direction of the hydraulic support is the X-axis, the hauling direction of the shearer is the Y-axis, and the vertical direction is the Z-axis. Take the base-cylinder pin of the first hydraulic support as the coordinate origin; use the floating connection mechanism manipulator model to obtain the position information X of the connector pin in the X-axis direction with the hydraulic support as the reference point i , compare it with the position information of the corresponding mid-armor feature point to obtain the error ΔX of a single set of floating connection mechanisms i ; Combine all the errors to calculate the overall error evaluation of the floating connection mechanism, and calculate the average value of the errors as The standard deviation is The overall error is

[0081]

[0082] Among them, the evaluation of the up-and-down error is specifically as follows:

[0083] Obtain the position of the first mid-armor in the Y-axis, and its value is the overall up-and-down parameter S; obtain the position information Y of the connector pin in the Y-axis direction with the hydraulic support as the reference point i , compare it with the position information of the corresponding mid-armor feature point to obtain the up-and-down difference D of a single set i ; If it is lower than S, assign a negative value, equal to S, assign 0, and higher than S, assign a positive value. The assigned value is given a weighting value Q less than 1 according to the interval where D i is located i , and finally calculate the overall up-and-down error as Among them, μ S is the mean value of the scores, and σ S is the standard deviation of the scores

[0084] Among them, the evaluation of the cutting trajectory error is specifically as follows:

[0085] Extract the cutting information of the rear drum of the shearer and the pose information of the scraper conveyor; use the LSTM neural network to input the historical pushing parameters (pushing amount) of the scraper conveyor and the floor undulation data, and output the theoretical trajectory prediction of the scraper conveyor after the pushing is completed; convert the cutting trajectory of the rear drum of the shearer into the global coordinate system as the projection reference plane, project the scraper conveyor trajectory onto the cutting trajectory plane through quaternion transformation, and calculate the offset ΔY of each mid-armor along the hauling direction of the shearer i and the offset ΔX in the advancing direction of the hydraulic support i , set the weight coefficients of the two directions to be ω X and ω Y respectively, and calculate the overall weighted average deviation

[0086]

[0087] Predict the scraper conveyor during the process of pushing the scraper and the hydraulic support during the process of moving the support, and obtain the position information after completing the action; fuse the straightness evaluation model of the hydraulic support group, the straightness evaluation model of the scraper conveyor, and the error factor evaluation model to complete the comprehensive evaluation ε of the overall spatial straightness of the fully mechanized coal mining face T = τ1f + τ2r + τ3E + τ4P + τ5Δ J .

[0088] Among them, τ1, τ2, τ3, τ4, and τ5 are the weights of the error sources of the hydraulic support group and the scraper conveyor; τ1 is the weight of the spatial straightness evaluation index f of the hydraulic support in the evaluation of the overall spatial straightness of the working face; τ2 is the weight of the spatial straightness evaluation index r of the scraper conveyor in the evaluation of the overall spatial straightness of the working face; τ3 is the weight of the overall error E of the floating connection mechanism in the evaluation of the overall spatial straightness of the working face; τ4 is the weight of the up and down error P in the evaluation of the overall spatial straightness of the working face; τ5 is the overall weighted deviation Δ of the cutting trajectory J The weight in the evaluation of the overall spatial straightness of the working face.

[0089] Compared with the prior art, the present application has the following beneficial effects:

[0090] 1. The concept of straightness is extended to the four-dimensional space-time level: In the process of straightness evaluation, the present application defines straightness at the three-dimensional space level, and considers the changes in process factors for prediction processing, making the straightness evaluation more reasonable and real-time.

[0091] 2. The evaluation of the internal attitude is added in terms of the straightness of the hydraulic support: The attitude of the hydraulic support can be divided into internal attitude and external attitude. Due to the complexity of the external environment, the factors affecting the straightness of the hydraulic support are not only the relationship between the supports, but also the internal attitude of the hydraulic support affected by the roof and floor. Therefore, adding the internal attitude evaluation significantly breaks through the limitations of the traditional straightness evaluation of the hydraulic support.

[0092] 3. Evaluation is carried out under a new benchmark, improving the accuracy: The traditional straightness evaluation method directly evaluates on the coal seam floor, which is greatly affected by the undulation of the floor. Transferring all the equipment to the same benchmark condition can greatly improve the accuracy of the straightness evaluation.

[0093] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0094] In this article, specific examples are used to elaborate on the principles and implementation manners of this application. The descriptions of the above embodiments are only used to help understand the method and its core idea of this application. At the same time, for those of ordinary skill in the art, according to the idea of this application, there will be changes in the specific implementation manners and application scopes. To sum up, the content of this specification should not be construed as a limitation to this application.

Claims

1. A method for evaluating the straightness of a working face based on full pose super spacetime transformation, characterized in that, Including: Obtain the equipment information and coal seam information at the working face; the equipment information includes the support point cloud information of the hydraulic support group in the shearer, the pose data of the shearer, and the actual trajectory of the scraper conveyor; the actual trajectory of the scraper conveyor is inversely obtained based on the pose data of the shearer and the spatial position relationship between the scraper conveyor and the shearer; Based on the support point cloud information of the hydraulic support group, the pose data of the shearer, and the actual trajectory of the scraper conveyor, construct a virtual model of the three machines based on the digital twin technology; the virtual model of the three-machine equipment includes a virtual model of the hydraulic support, a virtual model of the scraper conveyor, and a virtual model of the shearer; Based on the coal seam information and the virtual model of the three machines, construct a coal seam reference plane based on the coal seam transparency modeling method, the segmented plane fitting method, and the reference plane acquisition method; Based on the support point cloud information of the hydraulic support group, calculate the circumcenter and normal vector of the circumscribed circle by the three-point circle method for attitude curve fitting, and map the support point cloud information of the hydraulic support group to the coal seam reference plane through super-space-time transformation, and calculate the spatial baseline of the hydraulic support group; Evaluate the spatial straightness of the hydraulic support according to the sum of the distances from the measuring points on the actual axis to the spatial baseline of the hydraulic support group; Evaluate the spatial straightness of the scraper conveyor based on the projection of the characteristic points of the scraper conveyor and the radius of the snake-shaped cylinder; the snake-shaped cylinder is a cylinder that can envelope all the characteristic points of the scraper conveyor; According to the evaluation results of the spatial straightness of the hydraulic support and the evaluation results of the spatial straightness of the scraper conveyor, add the floating connection mechanism error, the up-and-down error, and the cutting trajectory error to establish an evaluation model for the overall spatial straightness of the working face, and obtain the overall spatial straightness of the working face.

2. The method for evaluating the straightness of a working face based on full pose super spacetime transformation according to claim 1, wherein The method for obtaining the support point cloud information of the hydraulic support group in the shearer is as follows: Install a three-dimensional lidar system at the middle position of the shearer body; During the traction of the shearer, scan the hydraulic support group based on the three-dimensional lidar system, and use a filtering method to eliminate the noise points during the scanning process, and segment the point clouds irrelevant to the hydraulic support group to obtain the first point cloud information of the hydraulic support group; Install two-dimensional radars at the column parts of each hydraulic support in the hydraulic support group; Based on the two-dimensional radar, scan each hydraulic support to obtain the second point cloud information of the hydraulic support group.

3. The method for evaluating the straightness of a working face based on full pose super spacetime transformation according to claim 2, wherein The method for obtaining the actual trajectory of the scraper conveyor is as follows: Use the extended Kalman filter algorithm to correct the pose data of the shearer; the pose data includes the position and direction of the shearer; Use the filtering algorithm to correct the position and direction of the shearer; Based on the three-dimensional lidar installed on the shearer body, obtain the spatial position relationship between the shearer and the hydraulic support group; Based on the position of the shearer, inversely obtain the actual trajectory of the scraper conveyor using the spatial position relationship between the scraper conveyor and the shearer.

4. The method for evaluating the straightness of a working face based on full pose super spacetime transformation according to claim 3, wherein, The coal seam transparency modeling method specifically includes: Through three-dimensional seismic exploration technology, obtain the formation reflection wave field information carrying the underground rock strata and geological structure characteristics to form the first floor information; Based on the first floor information, the shearer drum cutting information is weighted and fused to obtain the second floor information; the shearer drum cutting information is the vibration signal and cutting force information generated during the cutting of the coal seam by the drum during the coal mining process. According to the second floor information, the "equipment - coal seam floor" coupling relationship constructed in Unity3D is introduced, and the Bayesian data assimilation algorithm is introduced to obtain the third floor information, completing the transparency of the coal seam.

5. The method for evaluating the straightness of a working face based on full pose super spacetime transformation according to claim 4, characterized in that, The specific steps of the piecewise plane fitting method are as follows: According to the coal seam information, use Matlab to calculate the fitting polynomial, and use the stepwise regression method to determine the optimal order. Gradually increase the order to make the fitting surface coincide with the actually measured data points. Use the diff function in Matlab to determine the critical points of the polynomial. Use the second-order partial derivative and its determinant to determine the extreme points of the polynomial among the critical points. According to the extreme points, perform piecewise processing on the fitting surface to obtain a piecewise surface. Obtain the discrete point information on each piecewise surface. According to the discrete point information, use the least squares method to fit a plane and determine the objective function; the objective function is used to measure the distance from each discrete point to the fitting plane. Project the piecewise surface along the normal vector onto the fitting plane to determine the size of the fitting surface.

6. The method for evaluating the straightness of a working face based on full pose super spacetime transformation according to claim 5, characterized in that, The formula expression of the objective function is: Among them, the normal vectors A, B, and C respectively represent the direction of the fitting plane; x i , y i , z i are the coordinate values of the discrete points; D is the distance from the fitting plane to the origin; distancei represents the distance from the i-th discrete point to the fitting plane.

7. The method for evaluating the straightness of a working face based on full pose super spacetime transformation according to claim 6, characterized in that, Evaluate the spatial straightness of the hydraulic support according to the sum of the distances from the measuring points on the actual axis to the spatial baseline of the hydraulic support group, specifically including: Evaluate the spatial straightness of the hydraulic support according to the formula ​ Among them, (x ij , y ij , z ij ) are discrete points on each support base, where i represents the support serial number, j represents the number of characteristic circles on the support, x o is the average value of the x coordinate of the axis, y o is the average value of the y coordinate of the axis, z o is the average value of the z coordinate of the axis, and (l, m, n) is the direction vector of the spatial baseline in space.

8. The method for evaluating the straightness of a working face based on full pose super-time-space transformation according to claim 7, characterized in that, Evaluate the spatial straightness of the scraper conveyor based on the projection of the characteristic points of the scraper conveyor and the radius of the snake-shaped cylinder, specifically including: Select the center of the pin ear clearance of each middle trough of the scraper conveyor as the characteristic point, project the scraper conveyor onto the coal seam floor, and obtain the position information of the projection points of the characteristic points on the floor. According to the projection point position information, calculate the distance between the projection point and the fitting plane along the direction of the piecewise normal vector. According to the distance, move each characteristic point along the normal vector direction to obtain the moved position information; the moved position information is the position information of the middle trough after eliminating the influence of the coal seam floor. After performing a spatio-temporal transformation on the moved middle trough and the fitting plane, construct a snake-shaped cylinder that can envelope all the characteristic points. Evaluate the spatial straightness of the scraper conveyor according to the radius of the snake-shaped cylinder.

9. The method for evaluating the straightness of a working face based on full pose super-time-space transformation according to claim 8, characterized in that The formula expression of the evaluation model for the overall spatial straightness of the working face is: ε T = τ1f + τ2r + τ3E + τ4P + τ5Δ J ; Among them, τ1, τ2, τ3, τ4, and τ5 are the weights of the error sources of the hydraulic support group and the scraper conveyor; τ1 is the weight of the evaluation index f of the spatial straightness of the hydraulic support in the evaluation of the overall spatial straightness of the working face; τ2 is the weight of the evaluation index r of the spatial straightness of the scraper conveyor in the evaluation of the overall spatial straightness of the working face; τ3 is the weight of the overall error E of the floating connection mechanism in the evaluation of the overall spatial straightness of the working face; τ4 is the weight of the up-and-down error P in the evaluation of the overall spatial straightness of the working face; τ5 is the overall weighted deviation Δ of the cutting trajectory J The weight in the evaluation of the overall spatial straightness of the working face.

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