Real-time Precise Virtual Deduction Method for the Pose of the Floating Connection Mechanism of Fully Mechanized Mining Support and Transportation Equipment

Abstract

The present invention relates to a real-time precise virtual deduction method for the pose of a floating connection mechanism of fully-mechanized mining support and transportation equipment. Based on conformal geometry, the spatial combined motion of the floating connection mechanism is converted into the transformation relationship between points, lines and planes to obtain the motion law of the floating connection mechanism. By changing the rotation of each middle trough of the scraper conveyor, the change of the direction vector is realized, and then the update of the motion values of each structure of the floating connection mechanism is realized. Finally, the adaptive propulsion of the hydraulic support group and the scraper conveyor is realized. The scraper conveyor is discretely decomposed into several middle troughs, and driven based on the rotation of each middle trough to establish the pose reconstruction of the scraper conveyor based on coordinate information. The present invention gets rid of the influence of the motion sequence of different degrees of freedom of the floating connection mechanism, can directly solve the motion of each structure, and can reconstruct the motion of the floating connection mechanism relatively quickly after virtual application, and then can deduce the pose relationship between the hydraulic support and the scraper conveyor relatively quickly.

Description

Technical Field

[0001] The present invention relates to the technical field of fully mechanized coal mining face simulation technology. Specifically, it is a method for real-time accurate virtual deduction of the pose of a floating connection mechanism of fully mechanized coal mining support and transportation equipment. Background Technique

[0002] With the introduction of a series of major strategies on intelligent manufacturing in the country, the realization of the intelligent and unmanned fully mechanized coal mining face has become the primary task of current coal mine production. The establishment of a virtual fully mechanized coal mining face is the key to the digital twin fully mechanized coal mining face. However, in the current process of realizing the operation of the virtual fully mechanized coal mining face, the development of the coordination between the hydraulic support and the scraper conveyor is relatively slow. The reason is that the pushing mechanism connecting the hydraulic support and the scraper conveyor is a floating mechanism, and its movement is difficult to achieve in a virtual environment. As the key support and transportation equipment of the "three machines" in the fully mechanized coal mining face, the hydraulic support and the scraper conveyor determine the safety and efficiency of the entire fully mechanized coal mining face. Therefore, it is necessary to analyze the movement of the floating connection mechanism between the two.

[0003] In the existing technology, the invention patent application with the publication number CN110021224A discloses a simulation experiment device for the pushing process of a scraper conveyor under complex underground conditions. In the experimental device, the pushing mechanism is a key part connecting the scraper conveyor and the hydraulic support base. Through this pushing mechanism, the pushing of the scraper conveyor can be simulated for the pushing operation. However, when obtaining the pushing angles of each structure of the pushing mechanism, the pushing distance of the scraper conveyor, and the displacements at their connection points, it is necessary to install electronic components and electronic instruments such as shaft encoders, inclination sensors, infrared distance sensors, and cameras. The invention patent application with the publication number CN111287776A discloses a method for describing the attitude of a floating connection mechanism between a hydraulic support and a scraper conveyor. By simplifying the floating connection mechanism between the hydraulic support and the scraper conveyor into a manipulator model, the relational expressions of the motion parameters of the floating connection mechanism are determined based on the analytical method of industrial robot inverse kinematics; according to the step-by-step progressive screening method, the optimal solution is selected to determine the motion law of each structure of the floating connection mechanism; the motion law is programmed into the bottom layer of the simulation system, and when the virtual hydraulic support pushes the virtual scraper conveyor on the virtual floor, the precise motion of the virtual floating connection mechanism can be obtained. The invention patent application with the publication number CN111287776A discloses a method for obtaining the positions of a group of hydraulic supports based on an expert system. By establishing an expert system based on the motion parameters of the floating connection mechanism between the hydraulic support and the scraper conveyor, the relative positions between the hydraulic support and the scraper conveyor, and the position of the hydraulic support on the coal seam when the hydraulic support pushes the scraper conveyor on the coal seam; when the elongation length of the pushing cylinder and the inclination angle of the hydraulic support base on the coal seam are obtained underground in the coal mine, after querying and analyzing in the knowledge base, through the inference of the inference engine, the position of the hydraulic support corresponding to the virtual environment is obtained; after data processing of the obtained position of the hydraulic support, it is made to correspond to the position in the real underground coal mine, and finally the obtained position of the hydraulic support is output to the user interface. The master's degree thesis "Construction, Analysis and Application of the Spatial Motion Model of the Floating Connection Mechanism of Fully Mechanized Mining Support and Transportation Equipment in a VR Environment" analyzes and resolves the motion of the floating connection mechanism between the hydraulic support and the scraper conveyor. On this basis, the obtained motion law of the floating connection mechanism is applied to the virtual environment, and the construction of the virtual models of the coal seam and the equipment, and the construction of the virtual physical relationship are carried out, realizing the virtual floating connection between the hydraulic support and the scraper conveyor. In the master's degree thesis "Research on the Kinematics of Mechanisms Based on Conformal Geometric Algebra", conformal geometric algebra is applied to the kinematics of mechanisms, and the kinematic solutions of several typical series and parallel mechanisms and spatial link mechanisms are completed, exploring the application of conformal geometric algebra in the research of mechanism kinematics.The invention patent with the publication number CN106777486A discloses a formal analysis method and system for robotic arm motion planning based on conformal geometric algebra. Based on the conformal geometric algebra theory, geometric models corresponding to the basic components and motion planning constraints of the robot are constructed, and then the established geometric models are described in a high-order logic language to form a basic geometric logic model system of the robot. The geometric relation logic model of the specific robot motion process and the constraints or attributes of the motion process to be verified are combined into a logical proposition, and a logical reasoning engine is used to prove whether the logical proposition holds. The academic paper "Conformal Geometric Algebra Method for Displacement Analysis of Spatial Linkage Mechanisms" with the DOI number 10.3901 / JME.2021.09.039 introduces CGA into the displacement analysis of spatial linkage mechanisms, maps the joint feature points in the geometric model of the spatial linkage mechanism to a five-dimensional conformal space, establishes the CGA expression of the joint feature points, constructs several geometric bodies such as lines, planes or spheres based on the feature points, obtains the CGA-form expression equation of the joint intersection points to be calculated through the outer product calculation of the geometric bodies, and then directly obtains the cosine expression of the joint rotation angle or the input-output equation of the univariate high-degree displacement analysis without extraneous roots or missing roots of the spatial linkage mechanism by using the inner product or nilpotent property within the CGA theoretical framework, so as to obtain all symbolic form analytical methods for the displacement analysis of the spatial linkage mechanism.

[0004] The following problems exist in the current motion analysis process of the floating connection mechanism: (1) When analyzing the motion of the floating connection mechanism by designing relevant test devices, the assistance of sensors is indispensable, and the connection between the middle groove prototypes is not stable enough, resulting in a large deviation between the motion of each structural member of the floating connection mechanism and the actual situation; (2) The sequence of the yaw motion and the pitch motion of the push rod is random, and the designation of the action sequence will affect the analysis result when using spatial kinematics knowledge to analyze the motion of the floating connection mechanism, making the analysis result deviate from the actual motion to a certain extent. (3) Currently, the position of the connection point between the floating connection mechanism and the scraper conveyor is simply reduced to a fixed point, without considering the phenomenon that the position of the action point of the pushing mechanism will change with the undulation of the coal seam floor during the actual pushing process. Therefore, a more perfect analysis method needs to be proposed. As a common means in graphics, conformal geometric algebra has been well applied in the spatial kinematics of linkage mechanisms, especially in the kinematic analysis of robots, and certain progress has been made. However, the difference between underground research and ground research is that since only partial prior information can be obtained underground and the equipment operates in a spatial position, there is still a gap in the pose research of underground fully-mechanized mining equipment based on conformal geometric algebra. Therefore, the present invention combines conformal geometric algebra with the motion of the floating connection mechanism to realize the virtual reconstruction of the propulsion process of the hydraulic support group and the scraper conveyor. The present invention proposes a method for real-time and accurate virtual deduction of the pose of the floating connection mechanism of fully-mechanized mining support and transportation equipment. Summary of the Invention

[0005] The object of the present invention is to provide a real-time precise virtual deduction method for the pose of a floating connection mechanism of fully-mechanized mining support and transportation equipment. By analyzing the motion characteristics of each structure of the floating connection mechanism, the motion law under the condition of not considering the sequence of actions of each structure is obtained, and the conformal geometric algebra is combined with the motion of the floating connection mechanism to realize the virtual reconstruction of the propulsion process of the hydraulic support group and the scraper conveyor.

[0006] To solve the above technical problems, the technical solution adopted by the present invention is: a real-time precise virtual deduction method for the pose of a floating connection mechanism of fully-mechanized mining support and transportation equipment, including the following steps:

[0007] Step 1, analyze the motion of the floating connection mechanism of the hydraulic support and the scraper conveyor, establish a conformal geometric model, and based on conformal geometry, convert the spatial combined motion of the floating connection mechanism into the transformation relationship between points, lines and planes to obtain the motion law of the floating connection mechanism;

[0008] Step 2, based on the motion law of the floating connection mechanism, by changing the rotation of each middle trough of the scraper conveyor, realize the change of the direction vector, and then realize the update of the motion values of each structure of the floating connection mechanism. The hydraulic support is precisely pushed based on the obtained motion parameters of the pushing mechanism, and finally the adaptive propulsion of the hydraulic support group and the scraper conveyor is realized;

[0009] Step 3, discretely decompose the scraper conveyor into several middle troughs. The motion of the connection head of the floating connection mechanism depends on the change of the direction vector with the same deflection direction of the middle troughs. Based on the rotation of each middle trough for driving, establish the pose reconstruction of the scraper conveyor based on coordinate information.

[0010] Further, in step 1, analyze the motion of the floating connection mechanism based on conformal geometric algebra. The following is the analysis process:

[0011] Define the elongation of the pushing oil cylinder as the moving variable d 1 , the intersection point of the pushing oil cylinder body and the piston rod is point P 1 , the two rotational degrees of freedom of the pushing rod are defined as θ 2 、θ 3 , the rotational degree of freedom of the connection head is defined as θ 4 ; according to the characteristics of the pitching motion and yaw motion of the pushing rod, define that there are two points P 2 point and P 3 point on the connecting pin shaft between the pushing rod and the piston rod, and the length of the pushing rod is L 2 ; according to the characteristics of the yaw motion of the connection head, define that there is a P 4 point on the connecting pin shaft between the connection head and the pushing rod, and define the connection point between the connection head and the pushing ear seat of the scraper conveyor as P tPoint, the length of the connecting head is L 3 .

[0012] Given P t , n, π t , solve for the structural motion variables d 1 , θ 2 , θ 3 , θ 4 , the solution idea is: The position of P 4 can be obtained from P t and n. Let the moving variable d 1 be the unknown parameter, represent the position of P 2 through the outer product operation of the geometric body, and obtain the equation about d 2 and P 4 through the distance formula between P 1 . Finally, determine the joint angles through the inner product operation.

[0013] Furthermore, in the above solution method, first obtain the positions of each point:

[0014] Move P t along the -n direction by L3 to obtain P 4 ,

[0015]

[0016] where

[0017] Let the moving variable d 1 be the unknown, then the expression of the joint point P 2 is:

[0018]

[0019] where e 0 represents the origin, e ∞ represents the infinite point. Combining the following formula (3), the moving variable d 1 can be solved:

[0020]

[0021] Convert θ 2 into the included angle between the line l 12 * and l y * .

[0022]

[0023] where, l 12 * = p 1 ∧ p2 ∧e ∞ ,l y * = -e 12 I c , where e 12 is the unit vector of the straight line where points P 1 and P 2 are located, and I c is a pseudoscalar

[0024] θ 3 can be transformed into the included angle between the straight line l 34 * and l x * .

[0025]

[0026] where l 34 * represents the straight line where points P 3 and P 4 are located, and l x * represents the straight line where the x-axis is located.

[0027] θ 4 is transformed into the included angle between the plane π t * and the plane π 1 (xoz).

[0028]

[0029] Based on the above equations, the structural motion variables d 1 , θ 2 , θ 3 , θ 4 of the floating connection mechanism are obtained, where d 1 is the length of the piston rod, θ 2 is the angle change caused by the pitching motion of the push rod, θ 3 is the angle transformation caused by the yaw motion of the push rod, and θ 4 is the angle change caused by the yaw motion of the connector.

[0030] Furthermore, in step two, based on the obtained structural motion variables of the floating connection mechanism, first mark the key point as the theoretical position of P t at the middle trough of the virtual scraper conveyor, mark two key points at the edge of the middle trough as the direction vectors of the connector of the floating connection mechanism, and on the virtual hydraulic support push mechanism, for point P 1 , point P 2 , point P 3 and point P4 Mark the points, namely, mark at the junction of the virtual hydraulic cylinder and the virtual piston rod, at the pin shaft where the push rod is connected to the piston rod, and at the pin shaft where the connector is connected to the push rod. Convert each motion parameter in the obtained motion law in C#, and convert d 1 to Position, θ 2 to PitchAngle, θ 3 to YawAngle1, θ 4 to YawAngle2, program using the C# language, and by changing the rotation of each middle trough of the scraper conveyor, realize the change of the direction vector, and then realize the update of the motion values of each structure of the floating connection mechanism. The hydraulic support accurately pushes based on the obtained motion parameters of the pushing mechanism, and finally realizes the adaptive propulsion of the hydraulic support group and the scraper conveyor.

[0031] Furthermore, the virtual scraper conveyor refers to an equivalent model of the scraper conveyor established in a virtual environment created by Unity3D, which can realize the key functions of the actual scraper conveyor, including coal transportation, adaptive bending propulsion, and supporting the walking of the shearer.

[0032] Furthermore, the virtual hydraulic support refers to an equivalent model of the hydraulic support established in a virtual environment created by Unity3D, which realizes the key functions of the actual hydraulic support, including raising / lowering the column, pushing the scraper conveyor, moving the support, and extending / retracting the mutual assistance plate.

[0033] Furthermore, the virtual connection refers to using the motion laws of each structure of the floating connection mechanism obtained in a virtual environment created by Unity3D to enable the floating connection mechanism to adaptively act according to the relative positions of the virtual hydraulic support and the virtual scraper conveyor when the virtual hydraulic support pushes the virtual scraper conveyor, ensuring that the connection relationship between the two is always established.

[0034] After realizing the adaptive collaborative propulsion of the hydraulic support group and the scraper conveyor, the problems that may occur in the actual propulsion process can be converted into mathematical problems and then applied to the virtual environment for reliable analysis. For example, when the hydraulic support pushes, the position of the action point of the pushing mechanism is affected by the undulation of the coal seam, and the straightness problem of the scraper conveyor.

[0035] When virtually reconstructing the motion of the scraper conveyor, it is necessary to discretize the scraper conveyor into middle troughs and drive based on the rotation of each middle trough. During the actual mining process, the position coordinates of the scraper conveyor can be inversely obtained from the position of the shearer. Therefore, it is necessary to establish the attitude reconstruction of the scraper conveyor based on coordinate information, which is mainly divided into the following categories, where θ i is the relative deflection angle of the middle trough in the specified direction.

[0036] Furthermore, establish the attitude reconstruction of the scraper conveyor based on coordinate information. Without considering the undulation of the coal seam floor, that is, when the coal seam floor is a flat straight surface, the coordinate-attitude conversion of the scraper conveyor is as follows:

[0037] When the middle trough of the first section of the scraper conveyor solved does not deflect, the obtained formula is as follows:

[0038]

[0039] When the middle trough of the first section of the scraper conveyor solved deflects, the obtained formula is as follows:

[0040]

[0041] Furthermore, establish the attitude reconstruction of the scraper conveyor based on coordinate information. When considering the undulation of the coal seam floor, the coordinate-attitude conversion of the scraper conveyor is as follows:

[0042] Let ∠a be the roll angle of the middle trough, ∠b be the pitch angle of the middle trough, ∠c be the yaw angle of the middle trough, and three points' coordinates are collected for each middle trough;

[0043] In the yoz plane, l 1 = l·cosc, l i = l·cosc i , Δd is the clearance of the middle trough.

[0044] When the middle trough of the first section of the scraper conveyor solved does not deflect, the obtained formula is as follows:

[0045]

[0046] When the middle trough of the first section of the scraper conveyor solved deflects, the obtained formula is as follows:

[0047]

[0048] Secondly, in the xoz plane, when the middle trough of the first section of the scraper conveyor solved does not deflect, the obtained formula is as follows:

[0049]

[0050] When the middle trough of the first section of the scraper conveyor solved deflects, the obtained formula is as follows:

[0051]

[0052] After analyzing the movement of the floating connection mechanism and the laying posture of the scraper conveyor, the present invention proposes a real-time and accurate virtual deduction method for the posture of the floating connection mechanism of the comprehensive mining and support equipment, which gets rid of the influence of the movement order of different degrees of freedom of the floating connection mechanism and can directly solve the movement of each structure. After virtual application, the movement of the floating connection mechanism can be reconstructed more quickly, and then the posture relationship between the hydraulic support and the scraper conveyor can be deduced more quickly. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 It is the overall flow chart of the present invention;

[0054] Figure 2 is a conformal geometry model of the floating connection mechanism;

[0055] Figure 3 is the mobile variable d 1 Schematic diagram of the solution;

[0056] Figure 4 is the rotation variable θ 2 Schematic diagram of the solution;

[0057] Figure 5 is the rotation variable θ 3 Schematic diagram of the solution;

[0058] Figure 6 is the rotation variable θ 4 Schematic diagram of the solution;

[0059] Figure 7 The motion results of each structure obtained by applying the motion law of the floating connection mechanism;

[0060] Figure 8 It is a schematic diagram of the coordinate-attitude transformation of the scraper conveyor when the coal seam floor is a flat surface;

[0061] Figure 9 It is a schematic diagram of coordinate-posture conversion when the middle trough of the first section of the scraper conveyor does not deflect;

[0062] Figure 10 It is the local posture diagram of the middle trough when considering the undulation of the coal seam floor in the yoz plane;

[0063] Figure 11 It is a schematic diagram of coordinate-attitude transformation when the first middle trough of the scraper conveyor is not deflected in the xoz plane;

[0064] Figure 12 It is a comparison diagram of the deflection angle output of each middle slot in the virtual environment and the deflection angle of the middle slot obtained according to the coordinate-posture conversion. DETAILED DESCRIPTION

[0065] In the process of the coordinated advancement of a hydraulic support group and a scraper conveyor, there is a certain gap between the movement process of their connecting parts and the actual situation, resulting in a difference between the movement characteristics of the floating connection mechanism of the hydraulic support and the actual pushing accuracy of the hydraulic support. Therefore, it is necessary to analyze the movement characteristics of each structure of the floating connection mechanism to obtain the movement law under the condition of not considering the sequence of actions of each structure, realize the virtual reconstruction of the advancement process of the hydraulic support and the scraper conveyor, and lay a foundation for studying related problems in the advancement process.

[0066] Analyze the movement of the floating connection mechanism of the hydraulic support and the scraper conveyor. It has four degrees of freedom, including the translational movement of the pushing cylinder, the pitching movement and yaw movement of the pushing rod, and the yaw movement of the connecting head. According to the dimensions of the floating connection mechanism, establish a conformal geometric model for basic geometric elements such as its conversion points, lines, and surfaces, convert the spatial combined movement of the floating connection mechanism into the transformation relationship between points, lines, and surfaces, and obtain the movement law of the floating connection mechanism. When applying the movement law in a virtual environment, discretize and decompose the scraper conveyor into several intermediate troughs. The movement of the connecting head of the floating connection mechanism depends on the change of the direction vector consistent with the deflection direction of the intermediate trough, making the action position of the connecting head more flexible and closer to the actual situation, and making the research on related problems in the advancement process of the hydraulic support group and the scraper conveyor more reliable.

[0067] The hydraulic support described in the present invention is an important support device for the normal operation of the fully mechanized coal mining face. It is responsible for timely pushing the scraper conveyor to the coal wall and timely supporting the roof to avoid collapse.

[0068] The scraper conveyor described in the present invention is a transportation device for the normal operation of the fully mechanized coal mining face. When the shearer is operating, it will cut the coal wall with the scraper conveyor as the track, and the scraper conveyor will transport the cut coal blocks out.

[0069] The floating connection mechanism described in the present invention is a floating mechanism that connects fully mechanized mining and transportation equipment. Its main components include a hydraulic cylinder, a piston rod, a pushing rod, and a connecting head; its movement includes the elongation of the piston rod, the pitching movement and yaw movement of the pushing rod, and the yaw movement of the connecting head.

[0070] The present invention analyzes the movement of the floating connection mechanism based on conformal geometric algebra. The following is the analysis process.

[0071] Figure 1 This is the overall flowchart of the analysis method of the present invention. Figure 2 This is the conformal geometric model of the floating connection mechanism. As Figure 2 shown, define the elongation of the pushing cylinder as the moving variable d 1 , and the intersection point of the pushing cylinder body and the piston rod is point P 1 point, and the two rotational degrees of freedom of the pushing rod are defined as θ2 、θ 3 ; According to the characteristics of the pitching and yawing motions of the push rod, two points P 2 point and P 3 point are defined on the connecting pin shaft between the push rod and the piston rod, and the length of the push rod is L 2 ; According to the characteristics of the yawing motion of the connector, a P 4 point is defined on the connecting pin shaft between the connector and the push rod, and the connecting point between the connector and the push ear seat of the scraper conveyor is defined as P t point, and the length of the connector is L 3 ;

[0072] Given P t , n, π t , solve for the structural motion variables d 1 , θ 2 , θ 3 , θ 4 , P 4 's position is obtained from P t and n. Let the moving variable d 1 be an unknown parameter, represent the position of P 2 through the geometric outer product operation, obtain an equation about d 2 and P 4 using the distance formula between them, and finally determine the joint angles θ 1 , θ 2 , θ 3 , θ 4 .

[0073] First, obtain the positions of each point:

[0074] Figure 3 The schematic diagram for solving the moving variable d 1 is shown in the figure. Move P t along the -n direction by L3 to obtain P 4 ,

[0075]

[0076] Among them

[0077] Let the moving variable d 1 be the unknown, then the expression of the joint point P 2 is:

[0078]

[0079] where e 0 represents the origin, e ∞ represents the infinite point. Combining the following formula (3), the moving variable d1 :

[0080]

[0081] Determine the remaining variables:

[0082] Figure 4 The rotational variable θ is shown 2 in the schematic diagram for solving

[0083] θ 2 can be transformed into the angle between the straight line l 12 * and l y * as shown.

[0084]

[0085] where l 12 * = p 1 ∧ p 2 ∧ e ∞ and l y * = -e 12 I c where e 12 is the unit vector of the straight line where points P 1 and P 2 are located, and I c is a pseudoscalar

[0086] Figure 5 The rotational variable θ is shown 3 in the schematic diagram for solving. θ 3 can be transformed into the angle between the straight line l 34 * and l x * as shown.

[0087]

[0088] where l 34 * represents the straight line passing through points P 3 and P 4 , and l x * represents the x-axis.

[0089] Figure 6 The rotational variable θ is shown 4 in the schematic diagram for solving. θ 4 is transformed into the angle between the plane π t * and the plane π 1 (xoz).

[0090]

[0091] Based on the above equations, the kinematic variables d of the floating connection mechanism can be obtained. 1 , θ 2 , θ 3 , θ 4 , where d 1 is the length of the piston rod, θ 2 is the angle change caused by the pitching motion of the push rod, θ 3 is the angle transformation caused by the yaw motion of the push rod, and θ 4 is the angle change caused by the yaw motion of the connector.

[0092] Based on the kinematic variables of the floating connection mechanism, the motion of each structure can be applied in a virtual environment to realize the connection between the hydraulic support group and the scraper conveyor, ensuring reliable connection during the advancement process. First, mark the key points at the middle trough of the virtual scraper conveyor as the theoretical position of P t . Mark two key points at the edge of the middle trough as the direction vectors of the connector of the floating connection mechanism, and mark points P 1 , P 2 , P 3 and P 4 on the virtual hydraulic support pushing mechanism, that is, mark them at the junction of the virtual hydraulic cylinder and the virtual piston rod, the pin shaft where the push rod is connected to the piston rod, and the pin shaft where the connector is connected to the push rod respectively.

[0093] Convert each motion parameter in the obtained motion law into C# respectively. Convert d 1 to Position, θ 2 to PitchAngle, θ 3 to YawAngle1, θ 4 to YawAngle2. Program using the C# language. By changing the rotation of each middle trough of the scraper conveyor, the change of the direction vector is realized, and then the update of the motion values of each structure of the floating connection mechanism is realized. The hydraulic support is accurately pushed based on the obtained motion parameters of the pushing mechanism, and finally the adaptive advancement of the hydraulic support group and the scraper conveyor is realized. Make the scraper conveyor advance by one cutting depth to obtain the motion results of each structure of the pushing mechanism as shown in Figure 7 .

[0094] Among them, the virtual scraper conveyor refers to an equivalent model of the scraper conveyor established in a virtual environment created by Unity3D, which can realize all the key functions of the actual scraper conveyor, including coal transportation, adaptive bending advancement, and supporting the walking of the shearer.

[0095] Among them, the virtual hydraulic support refers to an equivalent model of the hydraulic support established in the virtual environment created by Unity3D, which can realize all the key functions of the actual hydraulic support, including raising / lowering the column, pushing the scraper conveyor, moving the support, extending / retracting the mutual assistance plate.

[0096] Among them, the virtual connection means that in the virtual environment created by Unity3D, by using the motion laws of each structure of the obtained floating connection mechanism, when the virtual hydraulic support pushes the virtual scraper conveyor, the floating connection mechanism can adaptively act according to the relative position between the virtual hydraulic support and the virtual scraper conveyor to ensure the establishment of the connection relationship between the two. As Figure 7 Shown are the motion parameter values of each structure of the floating connection mechanism after virtual connection.

[0097] Compare the parsing method of the floating connection mechanism in the present invention with the parsing method with the application number 202010102877.7. Under the control of the C# script, make the bending postures of the scraper conveyors under the two methods consistent, and compare the motion parameter values of each structure of the floating connection mechanism under the two methods. The comparison results are shown in the following table.

[0098] Serial number P1 PA1 YA11 YA12 P2 PA21 YA21 YA22 1 1.567 0.251 1.419 0.418 1.015 -1.446 1.539 0.334 2 1.581 0.232 1.359 0.360 1.490 -0.782 1.255 0.379 3 1.627 0.263 1.360 0.360 1.918 -0.380 0.997 0.372 4 1.621 0.250 1.355 0.355 1.309 -0.424 1.029 0.379 5 1.613 0.2521 1.283 0.283 1.257 -0.119 0.772 0.366 6 1.609 0.249 1.353 0.353 1.480 0.550 1.144 0.375 7 1.837 0.265 1.371 0.371 1.942 0.054 0.711 0.364 8 1.559 0.229 1.408 0.408 1.062 -0.329 0.965 0.364 9 1.594 0.199 1.416 0.416 1.902 -1.409 1.534 0.371 10 1.564 0.200 1.392 0.392 1.549 -1.411 1.550 0.368 11 1.544 0.186 1.399 0.399 1.269 -0.933 1.331 0.380

[0099] Among them, P1: elongation of the push rod, PA1: pitch angle of the push rod, YA11: yaw angle of the push rod, YA12: yaw angle of the connecting head, P2: elongation of the push rod, PA21: pitch angle of the push rod, YA21: yaw angle of the push rod, YA22: yaw angle of the connecting head. It can be seen that the motion values of each structure after applying the motion law of the floating connection mechanism obtained by the conformal geometric algebra method are more stable and more in line with the motion characteristics of the floating connection mechanism than those obtained by the spatial kinematics method. The position deviation values between the actual pushing point and the theoretical marking point on the middle trough after the hydraulic support is pushed in the virtual environment are shown in the following table, where D1 is the result after applying the motion law obtained by the conformal geometric algebra method, and D2 is the result after applying the motion law obtained by the spatial kinematics.

[0100]

[0101]

[0102] It can be seen from the above table that the result after applying the conformal geometric algebra fluctuates greatly, indicating that when the hydraulic support is pushed using this method, the position of the acting point of the pushing mechanism is irregular, and this phenomenon is closer to the actual situation.

[0103] In summary, the method for solving the motion law of the floating connection mechanism based on conformal geometric algebra proposed in the present invention is more reliable. Next, based on the motion law of the floating connection mechanism, the continuous advancement problem of the hydraulic support group and the scraper conveyor will be studied, and the coordinate-attitude conversion of the scraper conveyor will be used as an example for illustration.

[0104] (1) Coordinate-attitude conversion of the scraper conveyor when the undulation of the coal seam floor is not considered, that is, when the coal seam floor is a flat straight surface, as Figure 8 shown.

[0105] If the middle trough of the first section of the scraper conveyor being solved does not deflect as Figure 9 shown, the obtained formula is as follows:

[0106]

[0107] If the middle trough of the first section of the scraper conveyor being solved deflects, the obtained formula is as follows:

[0108]

[0109] (2) Coordinate-attitude conversion of the scraper conveyor when considering the undulation of the coal seam floor, such as the local attitude diagram of the middle trough shown in Figure 10 .

[0110] In Figure 10 , ∠a is the roll angle of the middle trough, ∠b is the pitch angle of the middle trough, ∠c is the yaw angle of the middle trough, and the coordinates of three points are collected for each middle trough, as shown by the points in Figure 10 .

[0111] In the yoz plane, l 1 = l·cos c, l i = l·cos c i , Δd is the middle trough clearance.

[0112] When the middle trough of the first section of the scraper conveyor being solved does not deflect, the obtained formula is as follows:

[0113]

[0114] If the middle trough of the first section of the scraper conveyor being solved deflects, the obtained formula is as follows:

[0115]

[0116] Secondly, in the xoz plane, if the middle trough of the first section of the scraper conveyor being solved does not deflect, the obtained formula is as follows:

[0117]

[0118] When the first middle trough of the scraper conveyor being solved deflects, the obtained formula is as follows:

[0119]

[0120] In Unity3D, mark two points on both sides of each middle trough of the scraper conveyor and mark 1 point at the center position, output the position coordinates of the three key points, and apply the above-mentioned attitude - coordinate conversion formula obtained to reconstruct the attitude of the scraper conveyor, output the deflection angles of each middle trough in the virtual environment, denoted as V - D in the table, and the deflection angles of the middle troughs obtained according to the coordinate - attitude conversion, denoted as C - D in the table, and obtain the results in the following table. The comparison results are as Figure 12 shown.

[0121] 1 2 3 4 5 6 7 8 9 10 11 V-D -1.746 -2.076 -2.341 -1.993 -1.464 -0.046 0.966 1.695 1.927 2.017 1.412 C-D -1.692 -2.068 -2.613 -1.532 -1.698 -0.002 0.182 1.109 2.103 1.807 1.803

[0122] From the above table and Figure 12 it can be seen that the deviation between the deflection angles of the middle troughs calculated according to the coordinates and the deflection angles of each middle trough in the virtual environment is small, and the deviation value is within 1°.

[0123] According to the real - time precise virtual deduction method of the pose of the floating connection mechanism based on conformal geometric algebra provided by the present invention, its advantages and outstanding innovation points are reflected in the following aspects:

[0124] 1. The present invention improves the analysis method of the motion law of the floating connection mechanism, improves the analysis accuracy. After applying the obtained motion law, a virtual mapping of the motion of the floating connection mechanism is established, realizing the high - precision virtual reconstruction of the coordinated advancement of the hydraulic support group and the scraper conveyor.

[0125] 2. The present invention can realize the virtual reconstruction of the motion of the scraper conveyor. Driven by the real - time data of the shearer, the coordinates of the middle troughs are obtained by inverting the trajectory of the scraper conveyor, and a coordinate - attitude conversion model of the scraper conveyor is established, realizing the virtual - real linkage of the advancement process of the hydraulic support group and the scraper conveyor during the mining process.

[0126] 3. During the process of pushing the hydraulic support, the role of the connecting head in the pin ear clearance during the pushing of the pushing mechanism is realized, making the pushing of the scraper conveyor by the hydraulic support more accurate and ensuring the reliability of the research on common engineering problems during the advancement process of the fully - mechanized coal mining face in the virtual environment.

[0127] 4. The present invention can quickly analyze the actions of the pushing mechanism according to the relative motion and position relationship between the hydraulic support and the scraper conveyor, making the actions of the virtual coal mining equipment more accurate and further improving the background analysis speed, and establishing a high - degree mapping of the advancement process of the hydraulic support group and the scraper conveyor.

[0128] 5. Considering the influence of complex geological conditions on the propulsion process, it can be compatible with various geological conditions, and can deeply explore the influence of coal seam undulation on mining. By combining the pose information of the scraper conveyor with the overall pose relationship of the hydraulic support group and the undulation of the coal seam floor, it provides decision-making support for the cutting process of the shearer.

Claims

1. A real-time precise virtual deduction method for the pose of the floating connection mechanism of fully-mechanized mining support and transportation equipment, characterized in that, it includes the following steps: Step 1, analyze the movement of the floating connection mechanism of the hydraulic support and the scraper conveyor, establish a conformal geometric model, convert the spatial combined movement of the floating connection mechanism into the transformation relationship between points, lines and planes, and obtain the movement law of the floating connection mechanism based on conformal geometric algebraic operations; Step 2, based on the movement law of the floating connection mechanism, by changing the rotation of each middle trough of the scraper conveyor, realize the change of the direction vector, and then realize the update of the movement values of each structure of the floating connection mechanism. The hydraulic support is precisely pushed based on the obtained movement parameters of the pushing mechanism, and finally realize the adaptive propulsion of the hydraulic support group and the scraper conveyor; Step 3, discretely decompose the scraper conveyor into several middle troughs. The movement of the connection head of the floating connection mechanism depends on the change of the direction vector with the same deflection direction of the middle trough. Drive based on the rotation angle of each middle trough, and establish the pose reconstruction of the scraper conveyor based on coordinate information.

2. The method according to claim 1, characterized in that: In step 1, analyze the movement of the floating connection mechanism based on conformal geometric algebra. The following is the analysis process: Define the elongation of the pushing cylinder as the moving variable d 1 , and the intersection point of the pushing cylinder body and the piston rod is point P 1 . Define the two rotational degrees of freedom of the pushing rod as θ 2 、θ 3 , and define the rotational degree of freedom of the connector as θ 4 ; According to the characteristics of the pitching and yawing motions of the pushing rod, define that there are two points P 2 and P 3 on the connecting pin shaft between the pushing rod and the piston rod. The length of the pushing rod is L 2 ; According to the characteristics of the yawing motion of the connector, define that there is a P 4 point on the connecting pin shaft between the connector and the pushing rod, and define the connecting point between the connector and the pushing lug of the scraper conveyor as point P t . The length of the connector is L 3 ; Known P t , n, π t , solve for the structural motion variables d 1 , θ 2 , θ 3 , θ 4 of the floating connection mechanism. The solution idea is as follows: The position of P 4 can be obtained from P t and n. Let the moving variable d 1 be an unknown parameter, represent the position of P 2 through the geometric outer product operation, and obtain an equation about d through the distance formula between P 2 and P 4 1 . Finally, determine the joint angles through the inner product operation.

3. The method according to claim 2, characterized in that: First obtain the positions of each point: Move P t along the -n direction by L3 to obtain P 4 , Among them Let the moving variable be d 1 be the unknown, then the expression of the joint point P 2 is: where e 0 represents the origin point, and e ∞ represents the infinite point. Combining the following formula (3), the moving variable d can be solved 1 : Let θ 2 can be transformed into the straight line l 12 * and the included angle with l y * of where l 12 * = p 1 ∧ p 2 ∧ e ∞ and l y * = -e 12 I c where e 12 is the unit vector of the straight line where points P 1 and P 2 are located, and I c is a pseudoscalar Let θ 3 be transformed into the straight line l 34 * and the included angle between l x * be where l 34 * represents the line 3 between P 4 and the two points P x * represents the line where the x-axis lies; Convert θ 4 into plane π t * and the angle between plane π 1 (xoz); Obtain the structural motion variables d 1 , θ 2 , θ 3 , θ 4 of the floating connection mechanism according to the above equations, where d 1 is the length of the piston rod, θ 2 is the angle change generated by the pitching motion of the push rod, θ 3 is the angle transformation generated by the yaw motion of the push rod, θ 4 is the angle change generated by the yaw motion of the connector.

4. The method according to claim 3, characterized in that: In Step 2, based on the obtained kinematic variables of each structure of the floating connection mechanism, first mark the key points at the middle trough of the virtual scraper conveyor as the theoretical positions of P t . Mark two key points at the edge of the middle trough as the direction vectors of the connection heads of the floating connection mechanism, and mark points P 1 , P 2 , P 3 and P 4 on the virtual hydraulic support pushing mechanism, that is, mark them at the junction of the virtual hydraulic cylinder and the virtual piston rod, the pin shaft where the pushing rod is connected to the piston rod, and the pin shaft where the connection head is connected to the pushing rod respectively; convert each motion parameter in the obtained motion law in C# respectively, convert d 1 to Position, θ 2 to PitchAngle, θ 3 to YawAngle1, θ 4 to YawAngle2, program using the C# language, realize the change of the direction vector by changing the rotation of each middle trough of the scraper conveyor, and then realize the update of the motion values of each structure of the floating connection mechanism. The hydraulic support makes precise pushing based on the obtained motion parameters of the pushing mechanism, and finally realizes the adaptive propulsion of the hydraulic support group and the scraper conveyor.

5. The method according to claim 4, characterized in that: The virtual scraper conveyor refers to an equivalent model of the scraper conveyor established in the virtual environment created by Unity3D, which can realize the key functions of the actual scraper conveyor, including coal transportation, adaptive bending propulsion, and supporting the walking of the shearer.

6. The method according to claim 4 or 5, characterized in that: The virtual hydraulic support refers to an equivalent model of the hydraulic support established in the virtual environment created by Unity3D, which realizes the key functions of the actual hydraulic support, including raising / lowering the column, pushing the scraper, moving the support, extending / retracting the mutual assistance plate.

7. The method according to claim 6, characterized in that: The virtual connection refers to using the movement laws of each structure of the floating connection mechanism obtained in the virtual environment created by Unity3D to realize that when the virtual hydraulic support pushes the virtual scraper conveyor, the floating connection mechanism can adaptively act according to the relative position of the virtual hydraulic support and the virtual scraper conveyor, ensuring that the connection relationship between the two is always established.

8. The method according to claim 4, characterized in that: In step 3, establish the pose reconstruction of the scraper conveyor based on coordinate information, without considering the undulation of the coal seam floor, that is, the coordinate-pose conversion of the scraper conveyor when the coal seam floor is a flat straight surface is as follows: If the first middle trough of the scraper conveyor being solved does not deflect, the obtained formula is as follows: If the first middle trough of the scraper conveyor being solved deflects, the obtained formula is as follows:

9. The method according to claim 8, characterized in that: In step 3, establish the pose reconstruction of the scraper conveyor based on coordinate information. The coordinate-pose conversion of the scraper conveyor considering the undulation of the coal seam floor is as follows: Let ∠a be the roll angle of the middle trough, ∠b be the pitch angle of the middle trough, and ∠c be the yaw angle of the middle trough. Three points' coordinates are collected for each section of the middle trough. In the yoz plane, l 1 = l·cosc, l i = l·cosc i , Δd is the middle trough clearance; when the first middle trough of the scraper conveyor does not deflect during calculation, the obtained formula is as follows: If the first section of the middle trough of the scraper conveyor being solved deflects, the obtained formula is as follows: Secondly, in the xoz plane, if the first section of the middle trough of the scraper conveyor being solved does not deflect, the obtained formula is as follows: If the first section of the middle trough of the scraper conveyor being solved deflects, the obtained formula is as follows:

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