A kind of space straightness calculation method of fully mechanized coal face based on virtual-real data fusion

Abstract

The present application belongs to the field of virtual reality technology, and specifically relates to a kind of fully mechanized coal face space straightness calculation method based on virtual-real data fusion. Including the following steps, S100: according to coal seam detection data to establish virtual coal seam, then the virtual coal seam is segmented and divided, and discrete coal seam section is obtained;S200: according to the real-time running track of coal mining machine, the advance of virtual scraper conveyor is realized;S300: three-dimensional laser radar is carried on the hydraulic support, and the hydraulic support information sensing system is built, the pose reconstruction of virtual hydraulic support is realized, and the straightness key vector of virtual hydraulic support is calculated;S400: the key pose parameters of floating connecting mechanism in virtual system are extracted by using the hydraulic support information sensing system;S500: the space straightness error of scraper conveyor, the space straightness error of hydraulic support group, the space straightness error of fully mechanized coal face and the space straightness of fully mechanized coal face facing the whole coal seam are calculated.

Description

Technical Field

[0001] This invention belongs to the field of virtual reality technology, specifically a method for calculating the spatial straightness of a fully mechanized mining face based on the fusion of virtual and real data. Background Technology

[0002] The straightness of fully mechanized mining faces has a significant impact on the safety and efficiency of coal mine production. In the process of developing intelligent coal mining, automatic straightening of fully mechanized mining faces is one of the key technologies for achieving intelligent coal mining, which requires high precision in calculating straightness errors. However, the control of the straightness of fully mechanized mining faces currently relies mostly on direct measurement methods for straightness detection in China. This means that the calculation of straightness errors depends on measurement data, and the measurement and calculation errors directly affect the overall straightness error.

[0003] Application No. 202111399857.1 defines the spatial straightness of a hydraulic support group. It uses a three-dimensional lidar to acquire the point cloud of the hydraulic support, and uses point cloud processing algorithms to extract the key point set of the hydraulic support. It uses the least squares method to fit the spatial straight line and calculate the distance error to realize the measurement of the spatial straightness of the hydraulic support group.

[0004] Application No. 202011070660.9 discloses a hydraulic support straightness detection device and its working method. By installing an additional device, a linear slide rail and a pulley assembly, on the hydraulic support, and installing a displacement sensor on one side of the linear slide rail to detect the sliding position of the pulley on the linear slide rail, the straightness of the hydraulic support on the working surface can be detected by detecting the position of the pulley assembly on the hydraulic support through the displacement sensor.

[0005] Application No. 201710442811.0 discloses a method for measuring the pose and straightness of downhole hydraulic support groups based on multiple image sequences. Square positioning marks are placed on the hydraulic support. The target image of the hydraulic support is acquired by a camera, and the positioning marks are extracted from the preprocessed image. Edge straight line fitting is performed on each positioning mark, and the normal vector of each positioning mark is calculated. The pose of each hydraulic support is determined by the normal vector. Then, the straightness of the hydraulic support group is calculated by the relationship between the positioning mark and the scraper.

[0006] Application number CN202010674474.X provides a horizontal control system and method for a fully mechanized mining face. It adopts a flexible substrate, fiber optic grating strings, flanges, fiber optic jumpers, fiber optic grating demodulators, three-dimensional fiber optic grating curvature sensors, network cables, and computers. During the operation and production process of the fully mechanized mining face, it uses dual-frequency laser interferometers and ultrasonic positioning to achieve high-precision detection of the linear and angular displacements of the moving parts of the three fully mechanized mining machines.

[0007] The above studies have investigated the straightness error of fully mechanized mining faces, but the following problems still exist: 1) The impact of coal seam undulations on straightness error during the advancement of the fully mechanized mining face is not considered. The impact of coal seam undulations on the spatial straightness of the fully mechanized mining face is different in the direction of the coal mining machine's travel and the overall advancement direction of the fully mechanized mining face; 2) The study on straightness error only analyzes the straightness of a single equipment group, without analyzing the straightness of the entire fully mechanized mining face based on the relative relationship between combined equipment groups; 3) When analyzing the straightness error of fully mechanized mining faces, the analysis only focuses on two-dimensional space and does not establish a three-dimensional error analysis model; 4) Currently, when detecting the straightness of fully mechanized mining faces, the existence of detection and calculation errors results in low accuracy of the calculated straightness error of the fully mechanized mining face. Summary of the Invention

[0008] To address the aforementioned problems, this invention provides a method for calculating the spatial straightness of a fully mechanized mining face based on the fusion of virtual and real data.

[0009] This invention adopts the following technical solution: a method for calculating the spatial straightness of a fully mechanized mining face based on virtual and real data fusion, comprising the following steps: S100: establishing a virtual coal seam based on coal seam detection data, and then dividing the virtual coal seam into segments to obtain discrete coal seam segments; S200: converting the scraper conveyor trajectory obtained from the real-time running trajectory of the coal mining machine into factors that can drive the scraper conveyor in the virtual environment after data conversion, thereby realizing the propulsion of the virtual scraper conveyor; S300: mounting a three-dimensional laser radar on the hydraulic support and building a hydraulic support information sensing system to extract the key poses of the hydraulic support during the actual mining process, realizing the virtual hydraulic support pose reconstruction, and calculating the key vector of straightness of the virtual hydraulic support; S400: extracting the key pose parameters of the floating connection mechanism in the virtual system using the hydraulic support information sensing system; S500: calculating the spatial straightness error of the scraper conveyor, the spatial straightness error of the hydraulic support group, the spatial straightness error of the fully mechanized mining face, and the spatial straightness of the fully mechanized mining face facing the entire coal seam based on the parameters obtained in S200-S300.

[0010] The specific process of step S100 is as follows: S101: Obtain a three-dimensional coal seam data point set by interpolating the coal seam detection data points, and construct a virtual coal seam based on the three-dimensional coal seam data point set; S102: Establish a coordinate system at the diagonal point closest to the outermost edge of the roadway at the junction of the return airway and the fully mechanized mining face before mining, as the absolute reference coordinate system for the entire fully mechanized mining face. Perform piecewise polynomial fitting on the three-dimensional data point set of the coal seam: ; in, y The dependent variable represents the polynomial fitted to the coal seam. x,z As the independent variable, a n ( n=0,1,…,n )and b m ( m=0, 1,…,m ) represent the polynomial coefficients of the two sub-expressions, n and m It represents the highest power of a polynomial.

[0011] S103: Calculation y=f ( x Determining the extreme points of () x, y The locations where planar coal seams need to be segmented ( x i , y i ); through calculation y = g ( z Determining the extreme points of () z , y The locations where planar coal seams need to be segmented ( z j ,y j If there are no inflection points, it indicates that the overall undulation trend of the coal seam is relatively gentle; if there are extreme points, the three-dimensional data point set of the coal seam is segmented according to the coordinates of the inflection points, and the range of each coordinate point in each segment of the coal seam is as follows: x ( x i-1 , x i ), y(min( f ( x i ), g ( z j )), max( f ( x i ), g ( z j ))), z ( z j-1 , z j ).

[0012] The specific process of step S200 is as follows: S201: Obtain real-time operating information of the coal mining machine. Based on the spatial positional relationship between the coal mining machine and the scraper conveyor, perform trajectory inversion of the scraper conveyor under the absolute reference coordinate system to obtain the trajectory information of the scraper conveyor, including the attitude angle changes of each middle trough of the scraper conveyor and the coordinates of the center position points of the two end lines of the middle trough. S202: Mark the key points of the scraper conveyor in the virtual system. Key points include the midpoint of the junction between the upper surfaces of two adjacent middle trough plates. P i (1) and P i (2) And the key points near the sidewall where the upper surfaces of the two adjacent middle trough plates meet. D i (1) and D i (2) ; S203: Obtain the pose of the scraper conveyor in the virtual system based on the key points of the scraper conveyor; The position and orientation of the scraper conveyor include the unit vector along the advancing direction of the fully mechanized mining face at the center of the trough. P h i And the direction vector of the middle slot along the direction of the coal mining machine's travel. P v i , P h i = P i (2) - P i (1) , P v i = P i - S i ; S204: Convert the virtual driving factors for the scraper conveyor, and convert the actual scraper conveyor trajectory coordinates into information in the virtual system that can drive the scraper conveyor forward—relative deflection angle; S205: Calculate the relative deflection angle between the virtual central troughs in real time; transform the parent-child relationship of the scraper conveyor according to the coal cutting direction of the coal mining machine; rotate each central trough according to the calculated relative deflection angle of the central trough, and finally realize the advancement of the virtual scraper conveyor.

[0013] The specific process of step S300 is as follows: S301: Establish a hydraulic support information sensing system to collect the attitude information of the hydraulic supports; install a three-dimensional lidar above the coal mining machine to collect point cloud data of the hydraulic support group columns, and realize the positioning of the hydraulic support group based on the coal mining machine position information.

[0014] S302: Determine the detection posture information of the hydraulic support in the virtual system.

[0015] A virtual information sensing system and a virtual 3D lidar for hydraulic supports are established in a virtual environment. When the coal mining machine is moving, point cloud data of the hydraulic support group columns are collected to obtain the point cloud PCD file. The point cloud is then filtered, segmented, and registered.

[0016] Simultaneously, a virtual 3D LiDAR is used to scan a virtual hydraulic support group in a virtual environment to obtain a virtual point cloud pose library of the virtual hydraulic support group. The PCD file is read to complete the virtual-real point cloud matching, and the pose of the actual hydraulic support group is estimated using the pose of the virtual hydraulic support group.

[0017] In the time dimension, point cloud data is matched with the sensing information of hydraulic support to obtain the detection attitude information of hydraulic support. The virtual hydraulic support attitude and the detected hydraulic support attitude are fused at a ratio of 4:1 to obtain the actual attitude information of hydraulic support.

[0018] Based on the actual positioning information of the coal mining machine, the trajectory information of the coal mining machine is read in the virtual system to realize the virtual reconstruction of the coal mining machine's running trajectory. The relative position between the coal mining machine and the point cloud is obtained based on the actual point cloud information obtained by scanning, so as to realize the positioning of the hydraulic support in the absolute reference coordinate system {O}.

[0019] S303: Extract the key vector for the straightness of the hydraulic support.

[0020] The pitch angle of the base is obtained from the hydraulic support information sensing system. α m 'and roll angle β m Based on the point cloud of the pillar obtained from the 3D lidar scan, the yaw angle γ of the base is determined. m ’ By reverse calculation, the attitude angle of the base can be obtained. α m ', β m ',γ m ’ Based on the attitude angle of the base and the structural dimensions of the base, the direction vector of the hydraulic support in the advancing direction of the fully mechanized mining face is obtained. Q h m Direction vector along the direction of the coal mining machine's travel Qv m : ; .

[0021] The specific steps of step S400 are as follows: S401: A gyroscope is embedded in the hydraulic support push rod, and an infrared rangefinder installed on the hydraulic support base measures the relative position of the hydraulic support and the scraper conveyor. At the same time, the corresponding sensors are virtually installed in the virtual system.

[0022] S402: In the virtual system, the elongation of the hydraulic support piston rod is obtained through the gyroscope embedded in the virtual hydraulic support push rod. d i Mark virtual key points at the pin joint where the push rod and piston rod meet, and set the Euler angle values ​​of the key points ( i 1 (i) , 0 , i 3 (i) ) is used as the attitude value of the push rod, where i 1 (i) This indicates the pitch angle value of the push rod. i 2 (i) Indicates the yaw angle value of the push rod; marks the key point at the connecting pin between the connector and the push rod, and records the Euler angle value of the key point ( 0 , 0 , i 3 (i) This serves as the attitude value of the connector. i 3 (i) This indicates the yaw angle value of the connector.

[0023] In step S500, the calculation process for the spatial straightness error of the scraper conveyor is as follows: A: Establish the local reference coordinate system on each central slot { O i m} Convert to global propulsion coordinate system { O i 0 Coordinates under} R 0 m =( x m , y m , z m This yields the coordinate trajectories of each central trough relative to the overall propulsion coordinate system. R jThe least squares method is used to fit a straight line in space, and the fitted line is taken as { O i 0 The ideal fitted line under}.

[0024] B: Calculate the straightness error of the scraper conveyor along the longitudinal advancement direction of the fully mechanized mining face: In the overall propulsion coordinate system { O i 0} below, based on vector P v m Coordinates of the middle groove R 0 m Key points were marked near the sidewall at the junction of the upper and lower surfaces of the two adjacent middle sections of the trough. D m (1) and D m (2) The coordinates are respectively P Dm(1) and P Dm(2) ; Where a is the width of the central groove and c is the length of the central groove; calculate P Dm(1) and P Dm(2) The maximum and minimum distances to the ideal fitted line are max d m with min d m The spatial straightness error Δ of the scraper conveyor s p ; ; Obtain the straightness error density of the lateral advance space of the scraper conveyor r s , m = 1, 2, ..., n, where n is the number of central slots.

[0025] C: Calculate the straightness error of the scraper conveyor along the transverse advancing direction of the fully mechanized mining face; Along the transverse advance direction of the fully mechanized mining face, the dihedral angle corresponding to the middle slot of each section ( β m , γ mThe unit vector under the parameter is p m 0 =(sin β m cosγ m , sin β m sinγ m cos β m ); Will P h m Transform to the global propulsion coordinate system { O i 0 The vector representing the edge line of the middle plate of each middle slot along the advancing direction of the fully mechanized mining face. p h m ; Directional error model of scraper conveyor in the advancing direction of fully mechanized mining face ΔS d , ; Scraper conveyor longitudinal propulsion space straightness error density r d , .

[0026] In step S500, the calculation process for the spatial straightness of the hydraulic support group is as follows: A: Calculations show that each hydraulic support is positioned in the overall propulsion coordinate system { O iH 0 The coordinate trajectory information under} is used to fit a spatial straight line using the least squares method, and the fitted straight line is used as the overall coordinate system to advance { O iH 0 The ideal fitted line under}.

[0027] B: Calculate the straightness error of the hydraulic support group along the longitudinal advance direction of the fully mechanized mining face: In the overall propulsion coordinate system of the hydraulic support group O iH 0} below, based on vector Q v m coordinates of hydraulic support position R OH m The key points of the bases of two adjacent hydraulic supports near the goaf were obtained.D m H(1) and D m H(2) The coordinates are respectively P Dm H(1) and P Dm H (1) ; calculate D m H(1) and D m H(2) The maximum and minimum distances to the ideal fitted line are max d m H with min d m H Spatial straightness error of hydraulic support group Δs p H , ; Obtain the straightness error density of the lateral advance space of the hydraulic support group r s H , m = 1, 2, ..., n, where n is the number of central slots.

[0028] C: Calculate the straightness error of the hydraulic support along the transverse advancing direction of the fully mechanized mining face: Along the transverse advancing direction of the fully mechanized mining face, the dihedral angle corresponding to each hydraulic support section ( β m H ,γ m H The unit vector under the parameter is p m 0(H) =(sin β m H cosγ m H , sin β m H sinγ m Hcos β m H ); Will Q h m Transform to the overall propulsion coordinate system of the hydraulic support group O iH 0 The vector represented by the bottom edge of the hydraulic support base near the goaf side along the advancing direction of the fully mechanized mining face is... q h m ; Directional error model of hydraulic support group in the advancing direction of fully mechanized mining face Δs d H ; ; Longitudinal advancement space straightness error density of hydraulic support group r d H , .

[0029] In step S500, the evaluation process for the spatial straightness error of the fully mechanized mining face is as follows: While ensuring the straightness of the hydraulic support and scraper conveyor, the overall motion characteristics of the floating connection mechanism are utilized. d i , i 1 (i) , i 2 (i) , i 3 (i) Evaluation of the consistency index of the shifting posture of the scraper conveyor and the floating connection mechanism of the hydraulic support group. r F , The straightness error density of the propulsion space of the hydraulic support group and the scraper conveyor, as well as the consistency index of the pushing posture of the scraper conveyor and the floating connection mechanism of the hydraulic support group, were obtained. r F Then, calculate , , r F The values ​​of are used to determine whether the straightness requirement of the fully mechanized mining face is met. If the values ​​of the three are between (0.9,1), (0.9,1), and (0.95,1) respectively, then the straightness requirement is met.

[0030] In step S500, the spatial straightness analysis process for the fully mechanized mining face as a whole coal seam is as follows: If the spatial straightness requirement of the fully mechanized mining face facing the entire coal seam meets the following: The fully mechanized mining face facing the entire coal seam meets the spatial straightness requirements.

[0031] Compared with the prior art, the present invention has the following beneficial effects: (1) The influence of coal seam undulation on straightness error during the advancement of fully mechanized mining face was fully considered. The influence of coal seam undulation on the spatial straightness of fully mechanized mining face from the direction of coal mining machine travel and the overall advancement direction of fully mechanized mining face was analyzed. The error analysis was integrated at the transition of coal seam undulation to ensure the globality of the spatial straightness error analysis of fully mechanized mining face.

[0032] (2) The relative relationship between the joint equipment groups was analyzed for the straightness of the overall fully mechanized mining face. Following the idea of ​​moving from the single to the whole, a straightness error model from a single equipment group to the entire fully mechanized mining face was established in the virtual scene based on real-time sensor data, ensuring the comprehensiveness of the overall spatial straightness analysis of the fully mechanized mining face.

[0033] (3) When analyzing the straightness error of the fully mechanized mining face, the coal seam is divided into segments according to the overall undulation. Based on the establishment of the coordinate system of the fully mechanized mining face production system, a three-dimensional error analysis model is established according to the coordinate system of each level, realizing the transformation from two-dimensional space to three-dimensional space when analyzing the straightness error of the fully mechanized mining face.

[0034] (4) Considering the current detection and calculation errors in the detection of the straightness of the fully mechanized mining face, which result in low accuracy of the calculated straightness error of the fully mechanized mining face, the method of fusing real-time sensor data and virtual data is adopted to control the posture and movement of the fully mechanized mining face equipment in the virtual scene, and then to analyze the straightness error of the fully mechanized mining face, thereby improving the accuracy of the error analysis results. Attached Figure Description

[0035] Figure 1 Framework for analyzing spatial straightness error in fully mechanized mining faces; Figure 2 Flowchart of virtual coal seam segmentation method; Figure 3 Schematic diagram of key positions of scraper conveyor; Figure 4 Schematic diagram of key pose extraction for spatial straightness of hydraulic support; Figure 5 Schematic diagram of key positions of hydraulic support group; Figure 6 Schematic diagram of the calculation model for the spatial straightness error of a fully mechanized mining face; Figure 7 A schematic diagram of the spatial straightness analysis of the entire fully mechanized mining face of the coal seam. Detailed Implementation

[0036] The technical solution of the present invention will be described in further detail below with reference to specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort should fall within the scope of protection of the present invention.

[0037] like Figure 1 The diagram shows the framework for analyzing the spatial straightness error of a fully mechanized mining face. The virtual coal seam, established based on coal seam detection information, is segmented. By installing relevant sensors and virtual sensors on the equipment of the fully mechanized mining face, the spatial straightness error of the fully mechanized mining face is analyzed segmentally through the fusion of virtual and real data. Finally, the spatial straightness error of the entire fully mechanized mining face is analyzed in conjunction with the overall undulation of the coal seam.

[0038] The specific implementation steps are as follows: S100: A virtual coal seam is established based on the coal seam detection data, and then the virtual coal seam is divided into segments to obtain discrete coal seam segments.

[0039] like Figure 2 The diagram shows the flowchart of the virtual coal seam segmentation method. Coal seam detection data points are interpolated to obtain a three-dimensional data point set of the coal seam, which is then saved and retrieved in XML file format. Given the significant undulations in the coal seam and the long length of the fully mechanized mining face, the coal seam segmentation method divides the coal seam into discrete segments.

[0040] A coordinate system is established at the diagonal point closest to the outermost edge of the roadway at the junction of the return airway and the pre-mining longwall face, serving as the absolute reference coordinate system for the entire longwall face. A piecewise representation of the overall three-dimensional trajectory equation of the coal seam is obtained through piecewise polynomial fitting. The storage format of the three-dimensional point set of the coal seam relative to the absolute reference coordinate system is (dingbandian_xi, dingbandian_yi, dingbandian_zi), (dibandian_xi, dibandian_yi, dibandian_zi). This is achieved by fitting the coal seam points to... , .

[0041] Through calculation Determining the inflection point (x, y) of the location where the coal seam needs to be segmented. ; through calculation The inflection point is determined by the location of the (z,y) plane coal seam where segments need to be divided. If there is no inflection point, it indicates that the overall undulation trend of the coal seam is relatively gentle; if there is an inflection point, the three-dimensional data point set of the coal seam needs to be segmented according to the coordinates of the inflection point. The range of each coordinate point in the segmented coal seam is as follows: ; ; .

[0042] S200: Based on the real-time trajectory of the coal mining machine, data is converted to realize the propulsion of the virtual scraper conveyor.

[0043] like Figure 3 The diagram shown is a key pose diagram of the scraper conveyor. This step will focus on... Figure 3 The key pose extraction is achieved in the process of extracting the key pose of the scraper conveyor.

[0044] S201: The coordinate system for the scraper conveyor's propulsion process is as follows: Three-level system For absolute reference coordinate system, To advance the coordinate system as a whole, Using a local reference coordinate system, based on the real-time operating information of the coal mining machine and the spatial relationship between the coal mining machine and the scraper conveyor, the trajectory of the scraper conveyor is inverted in the absolute reference coordinate system to obtain the trajectory information of the scraper conveyor, including the attitude angle changes of each middle trough of the scraper conveyor and the coordinates of the center points at both ends of the middle trough.

[0045] In the virtual environment created in Unity3D, adjacent middle slots are connected by a Character Joint component. The angle of each middle slot around the y-axis of the Character Joint component, i.e. the relative yaw angle of the middle slot, is controlled by transform.Rotate to realize the bending propulsion of the scraper conveyor.

[0046] S202: Mark key points for the scraper conveyor in Unity3D. Key points include the midpoint of the junction between the upper surfaces of two adjacent central trough plates. P i (1) and P i (2) And the key points near the sidewall where the upper surfaces of the two adjacent middle trough plates meet. D i (1) and D i (2) ; S203: Obtain the pose of the scraper conveyor in the virtual system based on the key points of the scraper conveyor; the scraper conveyor pose includes the unit vector of the central trough along the advancing direction of the fully mechanized mining face. P h i And the direction vector of the middle slot along the direction of the coal mining machine's travel. P v i Through calculation P h i = P i (2) - P i (1) , P v i = P i - S i The unit vectors of the advance direction of the fully mechanized mining face and the travel direction of the coal mining machine are obtained for each central slot.

[0047] Based on the obtained scraper conveyor inversion trajectory, the obtained scraper conveyor trajectory is converted into position coordinates and attitude angles that can drive the virtual reconstruction of the scraper conveyor's pose. ,in Local reference coordinate system representing the central groove In absolute coordinate system The three-dimensional coordinates This represents the pitch, roll, and yaw angles of the central trough. Based on the implementation of data-driven scraper conveyor pose reconstruction, vectors are obtained using C# scripts. and value.

[0048] S204: Convert the virtual driving factors for the scraper conveyor propulsion, and convert the actual scraper conveyor trajectory coordinates into information in the virtual system that can drive the scraper conveyor propulsion—relative deflection angle.

[0049] Based on the operating trajectory information of the coal mining machine, the trajectory coordinates of the scraper conveyor are obtained by inversion.

[0050] (1) in The coordinates of the trajectory of the middle trough of the scraper conveyor. These are the trajectory coordinates of the coal mining machine. R Let be the relative rotation matrix between the coal mining machine and the corresponding central trough. This refers to the relative position of the positioning device of the coal mining machine to the centerline of the traveling wheel.

[0051] The Rodrigues parameter is used to convert the actual scraper conveyor trajectory coordinates into information that can drive the scraper conveyor forward in the Unity3D environment—relative deflection angle.

[0052] The middle groove Position coordinates using vectors This means that the relative deflection angle between two adjacent middle troughs is determined by calculating the angle between two adjacent vectors. Given the vectors representing the positions of each middle trough of the scraper conveyor, the y-axis of the Character Joint component is used as the rotation axis n, and the relative deflection angle between two adjacent middle troughs is... and The relative rotation between two vectors can be determined by the following formula: (2) Set a central trough Relative to the middle trough The Euler angle difference is: yaw angle Pitch angle Roll angle The relationship between Euler angles and Rodrigues parameters is as follows: (3) Obtain the middle trough Relative to the middle trough The Euler angle difference of the deflection is: (4) Implement the algorithm in Matlab to perform the above content, specifically for the middle slot. Relative to the middle trough The Euler angle difference of the deflection is calculated, and the result is sent to Unity3D via UDP protocol. An "RotAngle" interface is then established in Unity3D to represent the angle of relative deflection between the central slots. i ",in i =1, 2, 3, ..., n.

[0053] S205: The relative deflection angle between the virtual central troughs is calculated in real time; the scraper conveyor changes its parent-child relationship according to the coal cutting direction of the coal mining machine; each central trough rotates according to the calculated relative deflection angle of the central trough, ultimately realizing the advancement of the virtual scraper conveyor.

[0054] The parent-child relationship of the scraper conveyor is changed as follows: when the coal cutting direction of the coal mining machine is consistent with the direction of the scraper conveyor from head to tail, the overall parent-child relationship of the scraper conveyor is set in the hierarchy of "head → middle trough 1 → middle trough 2 ... middle trough n → tail"; when the coal cutting direction of the coal mining machine is opposite to the direction of the scraper conveyor from head to tail, the overall parent-child relationship of the scraper conveyor is set in the hierarchy of "tail → middle trough n → middle trough n-1 ... middle trough 1 → head".

[0055] S300: Equip the hydraulic support with a 3D lidar and build a hydraulic support information sensing system to extract the key poses of the hydraulic support during the actual mining process, construct a virtual hydraulic support, and calculate the key vector of the straightness of the virtual hydraulic support.

[0056] like Figure 4 The diagram shows the key pose extraction of the spatial straightness of the hydraulic support. By equipping a three-dimensional lidar and building a hydraulic support information sensing system, the key pose of the hydraulic support during the actual mining process can be extracted.

[0057] S301: Establish a hydraulic support information sensing system to collect the attitude information of the hydraulic supports; install a three-dimensional lidar above the coal mining machine to collect point cloud data of the hydraulic support group columns, and realize the positioning of the hydraulic support group based on the coal mining machine position information.

[0058] Establishment of a hydraulic support information sensing system: An information sensing system for the hydraulic support is constructed by installing tilt sensors on both sides of the hydraulic support base to obtain the posture of the hydraulic support on the coal seam floor, installing ultrasonic sensors on the base to obtain the support height of the hydraulic support, installing pressure sensors and tilt sensors on the top beam to obtain the pressure on the top plate and the tilt angle of the top beam, installing tilt sensors at the four-link of the hydraulic support, and combining the posture of the top beam and the posture of the base to obtain the overall support posture of the hydraulic support. A gyroscope is embedded in the push rod of the hydraulic support, and an infrared rangefinder installed on the base of the hydraulic support measures the relative position of the hydraulic support and the scraper conveyor.

[0059] S302: Determine the detection posture information of the hydraulic support in the virtual system.

[0060] Construction of a Hydraulic Virtual Information Sensing System: A virtual information sensing system for the hydraulic support is established in a virtual environment. Virtual tilt sensors are installed on both sides of the hydraulic support base to obtain the posture of the virtual hydraulic support on the coal seam floor. Virtual ultrasonic sensors are installed on the base to obtain the support height of the virtual hydraulic support. Virtual pressure sensors and virtual tilt sensors are installed on the virtual roof beam to obtain the roof pressure and roof beam tilt angle of the hydraulic support. Virtual tilt sensors are installed at the four-link of the hydraulic support. Combined with the posture of the virtual roof beam and the base, the overall support posture of the virtual hydraulic support can be obtained. A virtual infrared rangefinder on the hydraulic support base measures the relative position of the virtual hydraulic support and the virtual scraper conveyor.

[0061] Determination of hydraulic support pose information through fusion of sensor information and 3D point cloud: Under the condition of selecting discrete coal seam sections, a 3D LiDAR is installed above the coal mining machine. During the movement of the coal mining machine, point cloud data of the hydraulic support group columns is collected to obtain the PCD file of the point cloud. The point cloud is then filtered, segmented, and registered. Simultaneously, a virtual 3D LiDAR scans the hydraulic support group in a virtual environment to obtain a virtual point cloud pose library of the hydraulic support group. A C# script reads the PCD file to complete the virtual-real point cloud matching. The pose of the hydraulic support group in the virtual environment is used to determine the pose of the actual hydraulic support. The attitude of the hydraulic support group is estimated. Simultaneously, point cloud information is matched with hydraulic support sensing information in the time dimension to obtain the detected attitude information of the hydraulic support. The virtual hydraulic support attitude and the detected hydraulic support attitude are fused at a ratio of 4:1 to obtain the actual attitude information of the hydraulic support. Based on the actual positioning information of the coal mining machine, the trajectory information of the coal mining machine is read in Unity3D to realize the virtual reconstruction of the coal mining machine's running trajectory. Based on the actual point cloud information obtained by scanning, the relative position between the coal mining machine and the point cloud is obtained, realizing the positioning of the hydraulic support in the absolute reference coordinate system {O}.

[0062] S303: Extract the key vector for the straightness of the hydraulic support.

[0063] like Figure 5 The diagram shows the key poses of the hydraulic support group. The coordinate system for the propulsion process of the hydraulic support group is as follows: Three-level system For absolute coordinate system, For the overall propulsion coordinate system of the hydraulic support group, This is a local reference coordinate system.

[0064] In the established hydraulic support information sensing system, the straightness of the hydraulic support group is related to the sensor detection results on the base. The pitch angle of the base can be obtained from the tilt sensor installed on the hydraulic support base. and roll angle Based on the point cloud of the pillar obtained from 3D lidar scanning, the yaw angle of the base can be determined. By reverse calculation, the attitude angle of the base can be obtained. Based on the attitude angle of the base and the structural dimensions of the base, the direction vector of the hydraulic support in the advancing direction of the fully mechanized mining face is obtained. Q h m Direction vector along the direction of the coal mining machine's travel Q v m .

[0065] (5) (6) in l The length of the base b This refers to the width of the base.

[0066] S400: Extracts key positional parameters of the floating connection mechanism in the virtual system using the hydraulic support information sensing system.

[0067] A gyroscope is embedded in the hydraulic support push rod, and an infrared rangefinder installed on the hydraulic support base measures the relative position of the hydraulic support and the scraper conveyor. At the same time, the corresponding sensors are virtually installed in the virtual system.

[0068] In the virtual system, the elongation of the hydraulic support piston rod is obtained through a gyroscope embedded in the virtual hydraulic support push rod. d i Mark virtual key points at the pin where the push rod and piston rod meet, and use the Euler angle values ​​of the key points as the attitude values ​​of the push rod, where represents the pitch angle value of the push rod and represents the yaw angle value of the push rod; mark key points at the connecting pin between the connector and the push rod, and use the Euler angle values ​​of the key points as the attitude values ​​of the connector and represents the yaw angle value of the connector.

[0069] S500: Based on the parameters obtained from S200-S300, calculate the spatial straightness error of the scraper conveyor, the spatial straightness error of the hydraulic support group, the spatial straightness error of the fully mechanized mining face, and the spatial straightness of the fully mechanized mining face of the coal seam as a whole.

[0070] A: Calculations show that each central trough is positioned in the overall propulsion coordinate system { O iH 0 The coordinate trajectory information under} is used to fit a spatial straight line using the least squares method, and the fitted straight line is used as the overall coordinate system to advance { O iH 0 The ideal fitted line under}.

[0071] B: Calculate the straightness error of the hydraulic support group along the longitudinal advance direction of the fully mechanized mining face: In the overall propulsion coordinate system of the hydraulic support group O iH 0} below, based on vector Q v m coordinates of hydraulic support position R OH m The key points of the bases of two adjacent hydraulic supports near the goaf were obtained. D m H(1) and D m H(2) The coordinates are respectively P Dm H(1) and P Dm H (1) ; calculate D m H(1) and D m H(2) The maximum and minimum distances to the ideal fitted line are max d m H with min d m H Spatial straightness error of scraper conveyor Δs p H , ; Obtain the straightness error density of the lateral advance space of the hydraulic support group r s H , m = 1, 2, ..., n, where n is the number of central slots.

[0072] C: Calculate the straightness error of the hydraulic support along the transverse advancing direction of the fully mechanized mining face: Along the transverse advancing direction of the fully mechanized mining face, the dihedral angle corresponding to each hydraulic support section ( β m H ,γ mH The unit vector under the parameter is p m 0(H) =(sin β m H cosγ m H , sin β m H sinγ m H cos β m H ); Will Q h m Transform to the overall propulsion coordinate system of the hydraulic support group O iH 0 The vector represented by the bottom edge of the hydraulic support base near the goaf side along the advancing direction of the fully mechanized mining face. q h m ; Directional error model of hydraulic support group in the advancing direction of fully mechanized mining face Δs d H ; ; Longitudinal advancement space straightness error density of hydraulic support group r d H , .

[0073] The evaluation process for the spatial straightness error of the fully mechanized mining face is as follows: While ensuring the straightness of the hydraulic support and scraper conveyor, the overall motion characteristics of the floating connection mechanism are utilized. d i , i 1 (i) , i 2 (i) , i 3 (i) Evaluation of the consistency index of the shifting posture of the scraper conveyor and the floating connection mechanism of the hydraulic support group. r F , The straightness error density of the propulsion space of the hydraulic support group and the scraper conveyor, as well as the consistency index of the pushing posture of the scraper conveyor and the floating connection mechanism of the hydraulic support group, were obtained. r F Then, calculate , , r F The values ​​of are used to determine whether the straightness requirement of the fully mechanized mining face is met. If the values ​​of the three are between (0.9,1), (0.9,1), and (0.95,1) respectively, then the straightness requirement is met.

[0074] The process of analyzing the spatial straightness of the fully mechanized mining face for the entire coal seam is as follows: If the spatial straightness requirement of the fully mechanized mining face facing the entire coal seam meets the following: .

Claims

1. A method for calculating the spatial straightness of a fully mechanized mining face based on virtual-real data fusion, characterized in that: Includes the following steps, S100: A virtual coal seam is established based on the coal seam detection data, and then the virtual coal seam is divided into segments to obtain discrete coal seam segments; S200: The scraper conveyor trajectory obtained by inverting the real-time running trajectory of the coal mining machine is converted into factors that can drive the scraper conveyor in a virtual environment after data conversion, thereby realizing the propulsion of the virtual scraper conveyor; S300: A three-dimensional lidar is mounted on the hydraulic support and a hydraulic support information sensing system is built to extract the key poses of the hydraulic support during the actual mining process, realize the virtual hydraulic support pose reconstruction, and calculate the key vector of the straightness of the virtual hydraulic support. The specific process of step S300 is as follows: S301: Establish a hydraulic support information sensing system to collect the attitude information of the hydraulic support; A three-dimensional lidar is installed above the coal mining machine to collect point cloud data of the hydraulic support group columns, thereby enabling the positioning of the hydraulic support group based on the coal mining machine's location information. S302: Determine the detection posture information of the hydraulic support in the virtual system; S303: Extract the key vector for the straightness of the hydraulic support; The pitch angle of the base is obtained from the hydraulic support information sensing system. α m 'and roll angle β m Based on the point cloud of the pillar obtained from the 3D lidar scan, the yaw angle γ of the base is determined. m ’ By reverse calculation, the attitude angle of the base can be obtained. α m ', β m ',γ m ’ Based on the attitude angle of the base and the structural dimensions of the base, the direction vector of the hydraulic support in the advancing direction of the fully mechanized mining face is obtained. Q h m Direction vector along the direction of the coal mining machine's travel Q v m : ； ； in l The length of the base b This refers to the width of the base. S400: Extracts key pose parameters of the floating connection mechanism in the virtual system using the hydraulic support information sensing system; The specific steps of step S400 are as follows: S401: A gyroscope is embedded in the hydraulic support push rod, and an infrared rangefinder installed on the hydraulic support base measures the relative position of the hydraulic support and the scraper conveyor. At the same time, the corresponding sensors are virtually installed in the virtual system. S402: In the virtual system, the elongation of the hydraulic support piston rod is obtained through the gyroscope embedded in the virtual hydraulic support push rod. d i Mark virtual key points at the pin joint where the push rod and piston rod meet, and set the Euler angle values ​​of the key points ( θ 1 (i) , 0 , θ 3 (i) ) is used as the attitude value of the push rod, where θ 1 (i) This indicates the pitch angle value of the push rod. θ 2 (i) Indicates the yaw angle value of the push rod; marks the key point at the connecting pin between the connector and the push rod, and records the Euler angle value of the key point ( 0 , 0 , θ 3 (i) This serves as the attitude value of the connector. θ 3 (i) This indicates the yaw angle value of the connector; S5 00: Based on the parameters obtained from S300-S400, calculate the spatial straightness error of the scraper conveyor, the spatial straightness error of the hydraulic support group, the spatial straightness error of the fully mechanized mining face, and the spatial straightness of the fully mechanized mining face facing the coal seam as a whole. In step S500, the evaluation process for the spatial straightness error of the fully mechanized mining face is as follows: While ensuring the straightness of the hydraulic support and scraper conveyor, the overall motion characteristics of the floating connection mechanism are utilized. d i , θ 1 (i) , θ 2 (i) , θ 3 (i) Evaluation of the consistency index of the shifting posture of the scraper conveyor and the floating connection mechanism of the hydraulic support group. ρ F , The straightness error density of the propulsion space of the hydraulic support group and the scraper conveyor, as well as the consistency index of the pushing posture of the scraper conveyor and the floating connection mechanism of the hydraulic support group, were obtained. ρ F Then, calculate , , ρ F The values ​​of are used to determine whether the straightness requirement of the fully mechanized mining face is met. If the values ​​of the three are between (0.9,1), (0.9,1), and (0.95,1) respectively, then the straightness requirement is met. ρ s The density of straightness error in the lateral advance space of the scraper conveyor. ρ s H The density of straightness error in the lateral advancement space of the hydraulic support group. ρ d The density of straightness error in the longitudinal propulsion space of the scraper conveyor. ρ d H The density of straightness error in the longitudinal advancement space of the hydraulic support group; The process of analyzing the spatial straightness of the fully mechanized mining face for the entire coal seam is as follows: If the spatial straightness requirement of the fully mechanized mining face facing the entire coal seam meets the following: The fully mechanized mining face facing the entire coal seam meets the spatial straightness requirements.

2. The method for calculating the spatial straightness of a fully mechanized mining face based on virtual-real data fusion as described in claim 1, characterized in that: The specific process of step S100 is as follows: S101: Obtain a three-dimensional coal seam data point set by interpolating the coal seam detection data points, and construct a virtual coal seam based on the three-dimensional coal seam data point set; S102: Establish a coordinate system at the diagonal point closest to the outermost edge of the roadway at the junction of the return airway and the fully mechanized mining face before mining, as the absolute reference coordinate system for the entire fully mechanized mining face. Perform piecewise polynomial fitting on the three-dimensional data point set of the coal seam: ； in, y The dependent variable represents the polynomial fitted to the coal seam. x,z As the independent variable, a n ( n=0,1,…,n )and b m ( m=0,1,…, m ) represent the polynomial coefficients of the two sub-expressions, n and m Represents the highest power of a polynomial; S103: Calculation y=f ( x Determining the extreme points of () x, y The locations where planar coal seams need to be segmented ( x i , y i ); through calculation y = g ( z Determining the extreme points of () z , y The locations where planar coal seams need to be segmented ( z j ,y j If there are no inflection points, it indicates that the overall undulation trend of the coal seam is relatively gentle; if there are extreme points, the three-dimensional data point set of the coal seam is segmented according to the coordinates of the inflection points, and the range of each coordinate point in each segment of the coal seam is as follows: x ( x i-1 , x i ), y(min( f ( x i ), g ( z j )), max( f ( x i ), g ( z j ))), z ( z j-1 , z j ).

3. The method for calculating the spatial straightness of a fully mechanized mining face based on virtual-real data fusion as described in claim 2, characterized in that: The specific process of step S200 is as follows: S201: Obtain real-time operating information of the coal mining machine. Based on the spatial positional relationship between the coal mining machine and the scraper conveyor, perform trajectory inversion of the scraper conveyor under the absolute reference coordinate system to obtain the trajectory information of the scraper conveyor, including the attitude angle changes of each middle trough of the scraper conveyor and the coordinates of the center position points at both ends of the middle trough. S202: Mark the key points of the scraper conveyor in the virtual system. Key points include the midpoint of the junction between the upper surfaces of two adjacent middle trough plates. P i (1) and P i (2) And the key points near the sidewall where the upper surfaces of the two adjacent middle trough plates meet. D i (1) and D i (2) ; S203: Obtain the pose of the scraper conveyor in the virtual system based on the key points of the scraper conveyor; The position and orientation of the scraper conveyor include the unit vector along the advancing direction of the fully mechanized mining face at the center of the trough. P h i And the direction vector of the middle slot along the direction of the coal mining machine's travel. P v i , P h i = P i (2) - P i (1) , P v i = P i - S i ; S204: Convert the virtual driving factors for the scraper conveyor, and convert the actual scraper conveyor trajectory coordinates into information in the virtual system that can drive the scraper conveyor forward—relative deflection angle; S205: Real-time calculation of the relative deflection angle between the virtual central troughs; parent-child relationship transformation of the scraper conveyor according to the coal cutting direction of the coal mining machine; Each central trough rotates according to the calculated relative deflection angle of the central trough, ultimately realizing the advancement of the virtual scraper conveyor.

4. The method for calculating the spatial straightness of a fully mechanized mining face based on virtual-real data fusion according to claim 3, characterized in that: S302: Determine the detection posture information of the hydraulic support in the virtual system; A virtual information sensing system and a virtual 3D lidar for hydraulic supports are established in a virtual environment; when the coal mining machine is moving, point cloud data of the hydraulic support group columns are collected to obtain the PCD file of the point cloud, and the point cloud is filtered, segmented and registered. Simultaneously, a virtual 3D lidar is used to scan a virtual hydraulic support group in a virtual environment to obtain a virtual point cloud pose library of the virtual hydraulic support group. The PCD file is read to complete the virtual-real point cloud matching, and the pose of the actual hydraulic support group is estimated using the pose of the virtual hydraulic support group. Meanwhile, point cloud data is matched with hydraulic support sensing information in the time dimension to obtain the detection attitude information of hydraulic support. The virtual hydraulic support attitude and the detected hydraulic support attitude are fused at a ratio of 4:1 to obtain the actual attitude information of hydraulic support. Based on the actual positioning information of the coal mining machine, the trajectory information of the coal mining machine is read in the virtual system to realize the virtual reconstruction of the coal mining machine's running trajectory. The relative position between the coal mining machine and the point cloud is obtained based on the actual point cloud information obtained by scanning, so as to realize the positioning of the hydraulic support in the absolute reference coordinate system {O}.

5. The method for calculating the spatial straightness of a fully mechanized mining face based on virtual-real data fusion as described in claim 1, characterized in that: In step S500, the calculation process for the spatial straightness error of the scraper conveyor is as follows: A: The local reference coordinate system on each central slot { O i m } Convert to global propulsion coordinate system { O i 0 Coordinates under} R 0 m =( x m , y m , z m This yields the coordinate trajectories of each central trough relative to the overall propulsion coordinate system. R j The least squares method is used to fit a straight line in space, and the fitted line is taken as { O i 0 The ideal fitted line under}; B: Calculate the straightness error of the scraper conveyor along the longitudinal advancement direction of the fully mechanized mining face: In the overall propulsion coordinate system { O i 0 } below, based on vector P v m Coordinates of the middle groove R 0 m Key points were marked near the sidewall at the junction of the upper and lower surfaces of the two adjacent middle sections of the trough. D m (1) and D m (2) The coordinates are respectively P Dm(1) and P Dm(2) ; Where a is the width of the central groove and c is the length of the central groove; calculate P Dm(1) and P Dm(2) The maximum and minimum distances to the ideal fitted line are max d m with min d m The spatial straightness error Δ of the scraper conveyor s p ; ； Obtain the straightness error density of the lateral advance space of the scraper conveyor ρ s , m = 1, 2, ..., n, where n is the number of central slots; C: Calculate the straightness error of the scraper conveyor along the transverse advancing direction of the fully mechanized mining face; Along the transverse advance direction of the fully mechanized mining face, the dihedral angle corresponding to the middle slot of each section ( β m , γ m The unit vector under the parameter is p m 0 =(sin β m cosγ m , sin β m sinγ m cos β m ); Will P h m Transform to the global propulsion coordinate system { O i 0 The vector representing the edge line of the middle plate of each middle slot along the advancing direction of the fully mechanized mining face. p h m ; Directional error model of scraper conveyor in the advancing direction of fully mechanized mining face ΔS d , ； Scraper conveyor longitudinal propulsion space straightness error density ρ d , 。 6. The method for calculating the spatial straightness of a fully mechanized mining face based on virtual-real data fusion according to claim 5, characterized in that: In step S500, the calculation process for the spatial straightness error of the hydraulic support group is as follows: A: Calculations show that each hydraulic support is positioned in the overall propulsion coordinate system { O iH 0 The coordinate trajectory information under} is used to fit a spatial straight line using the least squares method, and the fitted straight line is used as the overall coordinate system to advance { O iH 0 The ideal fitted line under}; B: Calculate the straightness error of the hydraulic support group along the longitudinal advance direction of the fully mechanized mining face: In the overall propulsion coordinate system of the hydraulic support group O iH 0 } below, based on vector Q v m coordinates of hydraulic support position R OH m The key points of the bases of two adjacent hydraulic supports near the goaf were obtained. D m H(1) and D m H(2) The coordinates are respectively P Dm H(1) and P Dm H(1) ; calculate D m H(1) and D m H(2) The maximum and minimum distances to the ideal fitted line are max d m H with min d m H Spatial straightness error of hydraulic support group Δs p H , ； Obtain the straightness error density of the lateral advance space of the hydraulic support group ρ s H , m = 1, 2, ..., n, where n is the number of hydraulic supports. l The length of the base b This refers to the width of the base. C: Calculate the straightness error of the hydraulic support along the transverse advancing direction of the fully mechanized mining face: Along the transverse advancing direction of the fully mechanized mining face, the dihedral angle corresponding to each hydraulic support section ( β m H ,γ m H The unit vector under the parameter is p m 0(H) =(sin β m H cosγ m H , sin β m H sinγ m H cos β m H ); Will Q h m Transform to the overall propulsion coordinate system of the hydraulic support group O iH 0 The vector represented by the bottom edge of the hydraulic support base near the goaf side along the advancing direction of the fully mechanized mining face. q h m ; Directional error model of hydraulic support group in the advancing direction of fully mechanized mining face Δs d H ; ； Longitudinal advancement space straightness error density of hydraulic support group ρ d H , 。

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