A relative position sensing and control system and method for a coal discharging mechanism and a rear conveyor

Abstract

The present invention relates to a relative position sensing and control system and method for a coal discharging mechanism and a rear conveyor. The system uses sensors to collect relevant data, and transmits the data to a host computer through a data acquisition card. The host computer analyzes and processes the data and directly issues a control command to the solenoid valve of the pulling jack to make the pulling jack operate. The method includes step (I) establishing a coal discharging position sensing model for the top coal caving support to solve the relative position relationship between the coal discharging mechanism and the rear conveyor; (II) judging whether the coal flow discharged by the coal discharging mechanism can accurately fall into the rear conveyor through the position sensing of the rear conveyor; (III) adjusting the relative position between the coal discharging mechanism and the rear conveyor to ensure that the coal flow on the coal discharging mechanism can fall into the rear conveyor to the greatest extent. The method can effectively adjust the position relationship between the coal discharging mechanism and the conveyor, make the top coal accurately fall into the rear conveyor, and maximize the loading efficiency and conveying efficiency.

Description

Technical Field

[0001] The present invention relates to a relative position sensing and control system and method for a coal discharging mechanism and a rear conveyor, and particularly to a sensing and control method for the relative position of a low-position coal caving support and a rear conveyor, belonging to the technical field of coal mining and transportation equipment. Background Art

[0002] The development of the top coal caving support has evolved from a high-position skylight single conveyor to a middle-position skylight double conveyor, and then to the currently mainly used low-position top coal caving support. The main equipment of the low-position top coal caving mining technology consists of a low-position top coal caving support and a double conveyor. The low-position top coal caving support generally includes a top beam, a shield beam, a tail beam, a tail beam flap, a base, a hydraulic column, a front connecting rod, and a rear connecting rod. When the low-position top coal caving support discharges coal, the tail beam swings downward to open the coal discharge port, and the top coal falls onto the rear conveyor through the coal discharge port. During the coal discharging process, it is easy for the coal discharge port to be misaligned with the rear conveyor, causing the top coal not to completely fall into the rear conveyor and scatter outside the conveyor, resulting in losses in top coal mining.

[0003] After retrieval, it is found that the Chinese patent document CN107605516A discloses a scraper conveyor behind a top coal caving hydraulic support with adjustable coal collecting function, belonging to the technical field of coal mining and transportation equipment, which consists of a scraper conveyor, a connecting base, a swing baffle, a swing adjusting hydraulic cylinder, a telescopic baffle, and a telescopic adjusting hydraulic cylinder. The connecting base is bolted to the scraper conveyor chute, the swing baffle is hinged to the upper end of the vertical plate of the connecting base, and the cylinder body and piston rod of the swing adjusting hydraulic cylinder are respectively hinged to the horizontal plate of the connecting base and the swing baffle. There are chute structures on both sides of the swing baffle, the telescopic baffle is installed in the chute, and the cylinder body and piston rod of the telescopic adjusting hydraulic cylinder are respectively hinged to the swing baffle and the telescopic baffle. By adjusting the angle of the swing baffle and the length of the telescopic baffle, the resistance during the forward movement of the scraper conveyor behind the support is reduced, effectively avoiding the scattering of falling coal behind the scraper conveyor behind the support, improving the coal recovery rate, and at the same time avoiding the occurrence of spontaneous combustion accidents caused by the scattering of falling coal left in the goaf. This technical solution adds a swing baffle and a telescopic baffle on one side of the rear conveyor, and through the action of the swing baffle and the telescopic baffle, it blocks the top coal from scattering outside the conveyor. Although this solution to a certain extent avoids the problem of top coal scattering outside, it does not fundamentally solve the problem of misalignment between the coal discharge port and the rear conveyor. In addition, the underground operation space is limited, and the additional swing baffle and telescopic baffle are not convenient to install.

[0004] Therefore, the key lies in starting from the relative position between the top coal caving support and the rear conveyor itself, and without adding additional large equipment, by adjusting the relative position between the coal discharge port of the top coal caving support itself and the rear conveyor, so that the coal discharge port always maintains a reasonable relative position with the rear conveyor, thereby ensuring that the top coal accurately falls into the rear conveyor. Summary of the Invention

[0005] To solve the problem that the coal discharge opening cannot be aligned with the conveyor during low-position coal discharge, the present invention proposes a method for perceiving and controlling the relative position between the coal discharge mechanism of a low-position top coal caving support and the rear conveyor. By real-time perceiving the spatial positions of the coal discharge mechanism of the low-position top coal caving support and the rear conveyor, it is judged whether the coal flow can accurately fall into the rear conveyor during top coal caving. If not, the position of the rear conveyor is adjusted by the telescopic movement of the pulling jack connecting the support base and the rear conveyor to ensure that the coal flow can accurately fall into the rear conveyor.

[0006] The present invention also provides a system for perceiving and controlling the relative position between the coal discharge mechanism and the rear conveyor.

[0007] The technical solution of the present invention is as follows:

[0008] A system for perceiving and controlling the relative position between the coal discharge mechanism and the rear conveyor includes a first inclination sensor, a second inclination sensor, a first displacement sensor, a second displacement sensor, a third displacement sensor, a data acquisition card, a host computer, a controller and a solenoid valve;

[0009] The first inclination sensor is arranged on the rear connecting rod, the second inclination sensor is arranged on the shield beam, the first displacement sensor is arranged on the tail beam jack, the second displacement sensor is arranged on the gob plate jack, and the third displacement sensor and the solenoid valve are arranged on the pulling jack;

[0010] The first inclination sensor, the second inclination sensor, the first displacement sensor, the second displacement sensor and the third displacement sensor are respectively connected to the host computer through the data acquisition card, and the host computer is connected to the solenoid valve through the controller.

[0011] A method for perceiving and controlling the relative position between the coal discharge mechanism and the rear conveyor, based on the above system, the method includes the following steps:

[0012] Ⅰ) Establish a perception model of the coal discharge position of the top coal caving support to solve the relative position relationship between the coal discharge mechanism and the rear conveyor;

[0013] Ⅱ) Judge whether the coal flow discharged by the coal discharge mechanism can accurately fall into the rear conveyor through the position perception of the rear conveyor;

[0014] Ⅲ) Adjust the relative position between the coal discharge mechanism and the rear conveyor to ensure that the coal flow on the coal discharge mechanism can fall into the rear conveyor to the greatest extent.

[0015] Preferably, the step Ⅰ) includes the following steps:

[0016] A. On the support base, taking the hinge point of the rear connecting rod and the base as the origin O of the coordinate system, the direction of the base length pointing to the rear conveyor as the X-axis, and the direction perpendicular to the base and pointing to the roof beam as the Y-axis, a spatial coordinate system O-XY is established and defined as the fixed coordinate system;

[0017] B. Define relevant parameters and establish a model: L1 is the height from the base to the lower hinge point of the rear connecting rod; L2 is the length of the rear connecting rod; L3 is the distance from the hinge point of the tail beam jack on the shield beam to the hinge point of the shield beam and the tail beam; L4 is the length of the tail beam jack; L5 is the length of the tail beam; L6 is the length of the plow jack; L7 is the length of the pulling jack; L8 is the width of the rear conveyor; θ1 is the angle between the rear connecting rod and the X-axis; θ2 is the angle between the shield beam and the X-axis; θ3 is the fixed angle between the top surface of the shield beam and the line connecting the hinge point of the tail beam jack on the shield beam and the hinge point of the shield beam and the tail beam; α is the angle between the line connecting the hinge point of the shield beam and the tail beam and the hinge point of the tail beam jack on the shield beam and the X-axis; β is the angle between the tail beam and the X-axis; γ is the angle between the line connecting the hinge points of the tail beam jack on the shield beam and the tail beam;

[0018] C. In the coordinate system O-XY, solve the real-time position coordinates of the end point Q of the tail beam plow;

[0019] (1) Solve the coordinates of the hinge point G of the shield beam and the tail beam in the coordinate system O-XY:

[0020] X G = L2cosθ1

[0021] Y G = L1 + L2sinθ1

[0022] Write the coordinates of point G in matrix form as:

[0023] G = [L2cosθ1 L1 + L2sinθ1] T (1)

[0024] (2) Establish a coordinate system O'-X'Y' at point G and define it as the moving coordinate system; among them, the X'-axis always points to the end of the tail beam along the length direction of the support tail beam; the Y'-axis always points perpendicular to the tail beam to the roof; solve the coordinates of the end point Q of the plow in this coordinate system, and the solution is as follows:

[0025] X' Q = L5 + L6

[0026] Y' Q = 0

[0027] Write the coordinates of point Q in matrix form as:

[0028] Q = [L5 + L6 0] T (2)

[0029] (3) Solve for the rotation matrix R and the translation vector T used when converting a point in the moving coordinate system O'-X'Y' to the fixed coordinate system O-XY, and the solution is as follows:

[0030] ∠FGN is the angle between a point F on the upper surface of the support shield beam and the hinge point N of the shield beam-tail beam jack at the hinge point G of the shield beam and the tail beam. Define the magnitude of ∠FGN as θ3; θ2 is the angle between the shield beam and the X-axis, then the angle between GN and the X-axis is:

[0031] α = θ3 - θ2 (3)

[0032] ∠FGN is the angle between the hinge point N of the shield beam-tail beam jack on the shield beam and a point P on the tail beam at the hinge point G of the shield beam and the tail beam. Define its magnitude as γ, and its magnitude changes with the length of the tail beam jack. According to the cosine theorem, γ can be obtained as:

[0033]

[0034] Then the angle β by which the moving coordinate system O'-X'Y' rotates around the rotation axis passing through point O and perpendicular to the plane of the fixed coordinate system O-XY can be obtained, and the solution is as follows:

[0035] β = π - γ - α (5)

[0036] The rotation matrix R of the moving coordinate system O'-X'Y' around the rotation axis passing through point O and perpendicular to the plane of the fixed coordinate system O-XY can be obtained as:

[0037]

[0038] At the same time, from the coordinates of point G in the fixed coordinate system O-XY and the coordinates of point G in the moving coordinate system O'-X'Y', the translation vector T for converting the moving coordinate system O'-X'Y' to the fixed coordinate system O-XY can be obtained as:

[0039]

[0040] (4) Solve for the coordinate value of point Q in the fixed coordinate system O-XY as:

[0041]

[0042] Substitute the rotation matrix R and the translation vector T obtained in step (3) to get:

[0043]

[0044] Then the X-axis coordinate of point Q in the fixed coordinate system O-XY can be obtained as:

[0045] XQ =(L5 + L6)cosβ + L2cosθ1 (10)

[0046] Y Q =(L5 + L6)sinβ + L1 + L2sinθ1 (11)

[0047] Substituting Eqs. (3), (4), and (5) into Eqs. (10) and (11) gives:

[0048]

[0049]

[0050] X Q 、Y Q are the coordinates of the end point Q of the tail beam flap in the fixed coordinate system O-XY.

[0051] Preferably, step (II) includes the following steps:

[0052] (1) Calculate the position coordinates of the rear conveyor. The same fixed coordinate system O-XY is used as that for calculating the position of the coal discharging mechanism, and the coordinate values of the two end points W and V of the rear conveyor in the symmetric plane of the low-position top coal caving support are solved;

[0053] The coordinates of points W and V are:

[0054] W = [L7 0] T (14)

[0055] V = [L7 + L8 0] T (15)

[0056] (2) Determine whether the coal flow can fall into the rear conveyor:

[0057] Assume that the height of the coal flow falling along the coal discharging mechanism is h. Assuming that the coal flow falls vertically due to the action of gravity when it reaches the end point of the flap, the coordinate range of the X-axis when the coal flow falls onto the rear conveyor is:

[0058] X min = X Q (16)

[0059]

[0060] To enable the coal flow falling from the coal discharging mechanism to accurately fall into the rear conveyor, the following geometric constraints need to be satisfied simultaneously:

[0061] X W < X min (18)

[0062] X max < XV (19)

[0063] Then, from equations (14) - (19), we can obtain:

[0064]

[0065] As can be seen from equation (20), whether the coal flow on the coal discharging mechanism can accurately fall into the rear conveyor is mainly related to the length L7 of the pulling jack; when the calculated X Q and L7 do not satisfy the above equation, it indicates that the coal flow cannot accurately fall into the rear conveyor. Then, it is necessary to adjust the length of the pulling jack L7 to make equation (20) hold, so that the coal flow on the coal discharging mechanism can accurately fall into the rear conveyor.

[0066] Preferably, step (III) includes the following steps:

[0067] From the above solution of the relative position between the coal discharging mechanism and the rear conveyor, it can be seen that when the X value of the W point coordinate on the rear conveyor is closer to the X value X of the Q point coordinate at the end of the tail beam insertion plate Q and L7 < X Q at the same time, the coal flow can fall into the rear conveyor to the greatest extent. Therefore, the control target is determined as: L7 = X Q ;

[0068] Select the PID control method to adjust the relative position between the coal discharging mechanism and the rear conveyor, specifically as follows:

[0069] According to the actual control requirements, define the input function of the PID controller as:

[0070] e(t) = X Q - L7 (21)

[0071] In the formula: e(t) is the input of the controller; u(t) is the output of the controller; y(t) is the output of the system;

[0072] Then, the output of the PID controller can be obtained as:

[0073]

[0074] In the formula: K P is the proportional coefficient, selected according to the type of the pulling jack; T i is the integral constant coefficient, selected according to the type of the pulling jack; T d is the differential constant coefficient, selected according to the type of the pulling jack.

[0075] The specific working process is: the controller obtains the X calculated by the upper computer QAfter the input e(t) formed by the difference between the value and the length L7 of the pulling jack measured by the displacement sensor, the corresponding control signal u(t) is output by the PID controller to the solenoid valve of the pulling jack to control the opening and closing and the position of the solenoid valve, and then control the hydraulic oil to enter the column cavity to make the pulling jack extend, or release the hydraulic oil in the column cavity to make the pulling jack shorten; the adjusted length L7 of the pulling jack can be measured in real time by the displacement sensor, and the difference between X Q and L7 is calculated. If it is not equal to 0, the control process is continued to be adjusted; thus, the relative position between the coal discharging mechanism and the rear conveyor is adjusted in real time, so that the coal flow on the coal discharging mechanism can fall into the rear conveyor to the greatest extent.

[0076] Preferably, it further includes step Ⅳ) correcting the position error of the coal discharge, and finely adjusting the relative position between the coal discharging mechanism and the rear conveyor through visual perception, including the following steps:

[0077] The camera of the first visual monitoring device takes pictures of the coal flow position accumulation and transmits the pictures to the image processing device. The image processing device processes the pictures and measures the distance between the first positioning mark point and the second positioning mark point, and compares it with the actual distance between the first positioning mark point and the second positioning mark point to obtain the picture scale; at the same time, the straight-line distance between the first positioning mark point in the picture and the midpoint of the bottom of the coal pile is measured and multiplied by the scale to obtain the actual distance between the first positioning mark point and the coal pile;

[0078] The distances between the first positioning mark point and the coal pile in two pictures transmitted by the camera at an interval of 1.5S are measured and calculated respectively and recorded as S1 and S2; it is judged whether the relative position between the first positioning mark point and the coal pile has changed. If S1 = S2, it indicates that the position of the coal pile has not changed relative to the first positioning mark point, which means that the coal discharge port and the rear conveyor are not aligned, that is, the coal pile fails to accurately fall on the rear conveyor, and the top coal discharged from the coal discharging mechanism falls outside the conveyor and cannot be safely transported by the rear conveyor, and the position between the coal discharging mechanism and the rear conveyor needs to be adjusted;

[0079] If S1≠S2, it indicates that the position of the coal pile has changed relative to the first positioning mark point. Further calculate the product of the translation speed of the rear conveyor scraper and the interval time and record it as S3. If S2 = S3, it indicates that the coal pile has completely and accurately fallen on the conveyor and is safely transported by the conveyor;

[0080] The second visual monitoring device installed on the rear connecting rod is used to judge whether the coal discharging speed is reasonable. By measuring the height of the coal flow accumulation on the conveyor, it can judge whether the coal discharging speed of the coal discharging mechanism is reasonable at this time; the camera takes pictures of the coal flow accumulation on the conveyor every 0.5S and transmits the pictures to the image processing device at the rear for processing. The image processing device sharpens the image, recognizes the image, measures the straight-line distance between the first positioning mark point and the second positioning mark point in the image, compares it with the actual distance between the two points, and obtains the scale in the image; at the same time, measures the height of each coal pile in the picture and takes the average value, converts the average height of the coal pile through the scale to obtain the actual average height of the coal pile, and compares whether the average height of the coal pile exceeds the conveying height range of the rear conveyor; if the average height of the coal pile exceeds the maximum height of the conveyor transportation, then increase the angle γ of the coal discharging mechanism to reduce the size of the coal discharging port, reduce the speed of the top coal falling, and reduce the height of the coal flow accumulation on the conveyor; if the average height of the coal pile is quite different from the maximum height of the conveyor transportation, then reduce the angle γ of the coal discharging mechanism, increase the size of the coal discharging port, increase the speed of the top coal falling, and increase the height of the coal flow accumulation on the conveyor; at the same time, when adjusting the angle of the coal discharging mechanism, calculate and analyze the relative position between the coal discharging port and the conveyor through the above steps I and II, and through the position adjustment in step III, make the top coal discharged from the coal discharging mechanism accurately fall into the conveyor, and the coal flow speed is appropriate.

[0081] Technical features and beneficial effects of the present invention:

[0082] 1. The present invention first proposes a method for perceiving and controlling the relative position between the coal discharging mechanism of the low-position top coal caving support and the rear conveyor. Using this method, the position relationship between the coal discharging mechanism and the conveyor can be effectively adjusted, so that the top coal caving can accurately fall into the rear conveyor, and the loading efficiency and conveying efficiency can be improved to the greatest extent.

[0083] 2. The present invention proposes a system for perceiving and controlling the relative position between the coal discharging mechanism of the low-position top coal caving support and the rear conveyor. Without the need to additionally increase too many physical devices, only relying on this system to adjust the position relationship between the coal discharging mechanism and the rear conveyor, reducing or even avoiding the occurrence of misalignment between the coal discharging port and the rear conveyor, and being more suitable for the narrow space of underground operations.

[0084] 3. The present invention first proposes a method for perceiving and controlling the relative position between the coal discharging mechanism of the low-position top coal caving support and the rear conveyor. There is a process of using sensors for position perception and control, and a process of using visual monitoring devices for error correction. The adjustment process is scientific, reasonable and has higher accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0085] Figure 1 It is a simplified model of the low-position top coal caving hydraulic support and the rear conveyor;

[0086] Figure 2 is the PID control flow chart;

[0087] Figure 3 is the schematic diagram of the installation positions of the first vision monitoring device and the second vision monitoring device;

[0088] Figure 4 is the flow chart of the position sensing and control method for the coal discharging mechanism and the rear conveyor;

[0089] In the figure: 1 is the tail beam jack; 2 is the coal discharging mechanism; 3 is the first vision monitoring device; 4 is the conveyor; 5 are the first positioning mark point and the second positioning mark point; 6 is the pulling jack; 7 is the second vision monitoring device; 8 is the rear connecting rod; 9 is the front connecting rod. Specific embodiments

[0090] The present invention will be further described below by way of examples in conjunction with the accompanying drawings, but is not limited thereto.

[0091] Example 1:

[0092] This embodiment provides a relative position sensing and control system for a coal discharging mechanism and a rear conveyor, including a first inclination sensor, a second inclination sensor, a first displacement sensor, a second displacement sensor, a third displacement sensor, a data acquisition card, a host computer, a controller and a solenoid valve;

[0093] The first inclination sensor is fixedly installed on the rear connecting rod 8, the second inclination sensor is fixedly installed on the shield beam, the first displacement sensor is fixedly installed on the tail beam jack 1, the second displacement sensor is fixedly installed on the scissor ram, and the third displacement sensor and the solenoid valve are fixedly installed on the pulling jack;

[0094] The first inclination sensor, the second inclination sensor, the first displacement sensor, the second displacement sensor and the third displacement sensor are respectively connected to the host computer through the data acquisition card, and the host computer is connected to the solenoid valve through the controller.

[0095] Among them, the inclination sensor and the displacement sensor can be selected from conventional commercially available products. The data acquisition card is selected as the Jiangsu Donghua Test DH8302 signal acquisition and analysis system, the host computer is selected as the Lenovo Qitian M43E-A013 desktop computer, and the solenoid valve is selected as the Delixi 4V210-08 AC220V two-position five-way solenoid valve.

[0096] The inclination sensor and the displacement sensor are used to collect various angles and displacement distances. For details, please refer to Figure 1 . The relevant data after collection is transmitted to the host computer through the data acquisition card. The host computer performs data analysis, processing and directly issues a control command to the solenoid valve of the pulling jack to make the pulling jack operate. The working principle of this system is asFigure 2 as shown

[0097] Embodiment 2:

[0098] This embodiment provides a method for perceiving and controlling the relative position between a coal discharging mechanism and a rear conveyor. Based on the system described in Embodiment 1, this method includes the following steps:

[0099] Ⅰ) Establish a perception model of the coal discharging position of the top coal caving support, and solve the relative position relationship between the coal discharging mechanism and the rear conveyor; the purpose of this step is to model and list the position relationship as a mathematical formula.

[0100] Ⅱ) By perceiving the position of the rear conveyor, determine whether the coal flow discharged by the coal discharging mechanism can accurately fall into the rear conveyor; the purpose of this step is to judge whether the coal flow can accurately fall into the rear conveyor.

[0101] Ⅲ) Adjust the relative position between the coal discharging mechanism and the rear conveyor to ensure that the coal flow on the coal discharging mechanism can fall into the rear conveyor to the greatest extent. The purpose of this step is to adjust the position relationship between the coal discharging mechanism and the rear conveyor to ensure that the coal flow falls into the rear conveyor to the greatest extent.

[0102] Specifically, the purpose of step Ⅰ) is to model and list the position relationship as a mathematical formula. Specifically, it further includes the following steps:

[0103] A. On the support base, take the hinge point of the rear connecting rod and the base as the origin O of the coordinate system, take the direction of the base length and pointing to the rear conveyor as the X-axis, and take the direction perpendicular to the base and pointing to the top beam as the Y-axis, so as to establish a space coordinate system O-XY and define it as a fixed coordinate system;

[0104] B. Define relevant parameters and establish a model: L1 is the height from the base to the lower hinge point of the rear connecting rod; L2 is the length of the rear connecting rod; L3 is the distance from the hinge point of the tail beam jack on the shield beam to the hinge point of the shield beam and the tail beam; L4 is the length of the tail beam jack; L5 is the length of the tail beam; L6 is the length of the chute jack; L7 is the length of the pulling jack; L8 is the width of the rear conveyor; θ1 is the angle between the rear connecting rod and the X-axis; θ2 is the angle between the shield beam and the X-axis; θ3 is the fixed angle between the top surface of the shield beam and the connecting line between the hinge point of the tail beam jack on the shield beam and the hinge point of the shield beam and the tail beam; α is the angle between the connecting line between the hinge point of the shield beam and the tail beam and the hinge point of the tail beam jack on the shield beam and the X-axis; β is the angle between the tail beam and the X-axis; γ is the angle between the connecting line of the hinge points of the tail beam jack on the shield beam and the tail beam;

[0105] C. In the coordinate system O-XY, solve the real-time position coordinates of the end point Q of the tail beam chute;

[0106] (1) Solve the coordinates of the hinge point G of the shield beam and the tail beam in the coordinate system O-XY:

[0107] X G = L2cosθ1

[0108] Y G = L1 + L2sinθ1

[0109] The coordinates of point G are written in matrix form as:

[0110] G = [L2cosθ1 L1 + L2sinθ1] T (1)

[0111] (2) Establish a coordinate system O'-X'Y' at point G and define it as the moving coordinate system; among them, the X'-axis always points to the end of the tail beam along the length direction of the support tail beam; the Y'-axis always points perpendicular to the tail beam to the roof; solve the coordinates of the end point Q of the insertion plate in this coordinate system, and the solution is as follows:

[0112] X' Q = L5 + L6

[0113] Y' Q = 0

[0114] The coordinates of point Q are written in matrix form as:

[0115] Q = [L5 + L6 0] T (2)

[0116] (3) Solve the rotation matrix R and translation vector T used when converting points in the moving coordinate system O'-X'Y' to the fixed coordinate system O-XY, and the solution is as follows:

[0117] ∠FGN is the angle between a point F on the upper surface of the support shield beam and the hinge point N of the shield beam-tail beam jack at the hinge point G of the shield beam and the tail beam, and the angle size is determined by the shield beam structure and does not change with the support condition of the support. Define the size of ∠FGN as θ3; θ2 is the angle between the shield beam and the X-axis, then the angle between GN and the X-axis is:

[0118] α = θ3 - θ2 (3)

[0119] ∠FGN is the angle between the hinge point N of the shield beam-tail beam jack and the point P on the tail beam at the hinge point G of the shield beam and the tail beam on the shield beam. Define its size as γ, and its size changes with the change of the length of the tail beam jack. By the cosine theorem, γ can be obtained as:

[0120]

[0121] Then the angle β of the rotation of the moving coordinate system O'-X'Y' around the rotation axis passing through point O and perpendicular to the plane of the fixed coordinate system O-XY can be obtained, and the solution is as follows:

[0122] β = π - γ - α (5)

[0123] The rotation matrix R of the moving coordinate system O'-X'Y' about the rotation axis passing through point O and perpendicular to the plane of the fixed coordinate system O-XY can be obtained as follows:

[0124]

[0125] At the same time, from the coordinates of point G in the fixed coordinate system O-XY and the coordinates of point G in the moving coordinate system O'-X'Y', the translation vector T for converting the moving coordinate system O'-X'Y' to the fixed coordinate system O-XY can be obtained as follows:

[0126]

[0127] (4) Solve for the coordinate values of point Q in the fixed coordinate system O-XY as:

[0128]

[0129] Substitute the rotation matrix R and translation vector T obtained in step (3) to get:

[0130]

[0131] Then the X-axis coordinate of point Q in the fixed coordinate system O-XY can be obtained as:

[0132] X Q = (L5 + L6)cosβ + L2cosθ1 (10)

[0133] Y Q = (L5 + L6)sinβ + L1 + L2sinθ1 (11)

[0134] Substitute equations (3), (4), and (5) into equations (10) and (11) to get:

[0135]

[0136]

[0137] X Q 、Y Q are the coordinates of the end point Q of the tail beam insertion plate in the fixed coordinate system O-XY.

[0138] Preferably, step (II) includes the following steps:

[0139] (1) Calculate the position coordinates of the rear conveyor. Use the same fixed coordinate system O-XY as that for calculating the position of the coal discharging mechanism, and solve for the coordinate values of the two end points W and V of the rear conveyor in the symmetric plane of the low-position top coal caving support;

[0140] The coordinates of point W and point V are:

[0141] W = [L70] T (14)

[0142] V = [L7 + L80] T (15)

[0143] (2) Determine whether the coal flow can fall into the rear conveyor:

[0144] Assume that the height of the coal flow falling along the coal discharging mechanism is h. Assuming that the coal flow falls vertically due to the action of gravity when it reaches the end point of the insertion plate, the coordinate range of the X-axis when the coal flow falls onto the rear conveyor is:

[0145] X min = X Q (16)

[0146]

[0147] To enable the coal flow falling from the coal discharging mechanism to accurately fall into the rear conveyor, the following geometric constraints need to be satisfied simultaneously:

[0148] X W < X min (18)

[0149] X max < X V (19)

[0150] Then, from equations (14) - (19), it can be obtained that:

[0151]

[0152] As can be seen from equation (20), whether the coal flow on the coal discharging mechanism can accurately fall into the rear conveyor is mainly related to the length L7 of the pulling jack; when the calculated X Q does not satisfy the above equation with L7, it indicates that the coal flow cannot accurately fall into the rear conveyor. Then, it is necessary to adjust the length of the pulling jack L7 to make equation (20) hold, so that the coal flow on the coal discharging mechanism can accurately fall into the rear conveyor.

[0153] Preferably, step (III) includes the following steps:

[0154] When the coal discharging mechanism and the rear conveyor satisfy equation (20), it can be ensured that the coal flow on the coal discharging mechanism can accurately fall into the rear conveyor. However, during the coal discharging process, the height h of the coal flow is not easy to measure. Therefore, when adjusting and controlling the relative position of the rear conveyor and the coal discharging mechanism, it should be combined with the actual situation, and after adjustment, the coal flow falling from the coal discharging mechanism can fall into the rear conveyor to the greatest extent to reduce coal waste;

[0155] From the relative positions of the coal discharging mechanism and the rear conveyor obtained above, it can be seen that when the magnitude of the X value L7 of the W point coordinate on the rear conveyor is closer to the X value X of the Q point coordinate at the end of the tail beam insertion plate and L7 < X Q and L7 < X Q at this time, the coal flow can fall into the rear conveyor to the greatest extent. Therefore, the control target is determined as: L7 = X Q .

[0156] The PID control method is selected to adjust the relative positions of the coal discharging mechanism and the rear conveyor, specifically as follows:

[0157] According to the actual control requirements, the input function of the PID controller is defined as:

[0158] e(t) = X Q -L7 (21)

[0159] In the formula: e(t) is the input of the controller; u(t) is the output of the controller; y(t) is the output of the system;

[0160] Then the output of the PID controller can be obtained as:

[0161]

[0162] In the formula: K P is the proportionality coefficient, selected according to the model of the pulling jack; T i is the integral constant coefficient, selected according to the model of the pulling jack; T d is the differential constant coefficient, selected according to the model of the pulling jack.

[0163] The specific working process is as follows: After the controller obtains the input e(t) formed by the difference between the X Q value calculated by the upper computer and the length L7 of the pulling jack measured by the displacement sensor, the corresponding control signal u(t) is output through the PID controller to the solenoid valve of the pulling jack to control the opening and closing and the position of the solenoid valve. Then, it controls the hydraulic oil to enter the column cavity to make the pulling jack extend, or releases the hydraulic oil in the column cavity to make the pulling jack shorten; the adjusted length L7 of the pulling jack can be measured in real time through the displacement sensor, and the difference between X Q and L7 is calculated. If it is not equal to 0, the control process continues to be adjusted; thus, the relative positions of the coal discharging mechanism and the rear conveyor are adjusted in real time, so that the coal flow on the coal discharging mechanism can fall into the rear conveyor to the greatest extent.

[0164] Example 3:

[0165] As Figure 3As shown in the figure, this embodiment provides a method for perceiving and controlling the relative position between a coal discharging mechanism and a rear conveyor. The method steps are as described in Embodiment 2, and the difference lies in that: it further includes step Ⅳ) correcting the position error of the coal flow dropping position, and finely adjusting the relative position between the coal discharging mechanism 2 and the rear conveyor 4 through visual perception; a first visual monitoring device 3 and a second visual monitoring device 7 are respectively installed on the coal discharging mechanism 2 and the rear connecting rod 8 in advance. The visual monitoring device is composed of a camera, an image processing device, a first positioning mark point, a second positioning mark point 5, an LED light source, etc. Both the first positioning mark point and the second positioning mark point are arranged on the side guard plate of the rear conveyor, and the two points are arranged at the same height and are 250 mm apart. Reflective plates are installed on both the first positioning mark point and the second positioning mark point. When the LED light source hits the reflective plate, the bright light reflected by the reflective plate can be captured by the camera. Even in the underground with poor lighting and harsh environment, the camera can still accurately identify and photograph the reflective plate to determine the positioning mark point.

[0166] Step Ⅳ) further includes the following steps:

[0167] The camera of the first visual monitoring device takes pictures of the coal flow position accumulation situation and transmits the pictures to the image processing device. The image processing device processes the pictures and measures the distance between the first positioning mark point and the second positioning mark point, and compares it with the actual distance between the first positioning mark point and the second positioning mark point to obtain the picture scale; at the same time, measure the straight-line distance between the first positioning mark point and the midpoint of the bottom of the coal pile in the picture, and multiply it by the scale to obtain the actual distance between the first positioning mark point and the coal pile;

[0168] By respectively measuring and calculating the distances between the first positioning mark point and the coal pile in two pictures transmitted by the camera at an interval of 1.5 s, denoted as S1 and S2; judge whether the relative position between the first positioning mark point and the coal pile has changed. If S1 = S2, it indicates that the position of the coal pile has not changed relative to the first positioning mark point, which means that the coal discharging port and the rear conveyor are not aligned, that is, the coal pile fails to accurately fall on the rear conveyor. The top coal discharged from the coal discharging mechanism falls outside the conveyor and cannot be safely transported by the rear conveyor. It is necessary to adjust the position between the coal discharging mechanism and the rear conveyor;

[0169] If S1 ≠ S2, it indicates that the position of the coal pile has changed relative to the first positioning mark point. Further calculate the product of the translation speed of the rear conveyor scraper and the interval time, denoted as S3. If S2 = S3, it indicates that the coal pile has completely and accurately fallen on the conveyor and is safely transported by the conveyor;

[0170] The second visual monitoring device installed on the rear connecting rod is used to judge whether the coal discharging speed is reasonable by measuring the height of the coal flow accumulation on the conveyor to determine whether the coal discharging speed of the coal discharging mechanism is reasonable at this time; the camera takes pictures of the coal flow accumulation on the conveyor every 0.5 seconds and transmits the pictures to the image processing device at the rear for processing. The image processing device sharpens the image, recognizes the image, and measures the straight-line distance between the first positioning mark point and the second positioning mark point in the image, and compares it with the actual distance between the two points (the actual distance between the first positioning mark point and the second positioning mark point is determined during installation) to obtain the scale in the image; at the same time, measure the height of each coal pile in the picture and take the average value, convert the average height of the coal pile through the scale to obtain the actual average height of the coal pile, and compare whether the average height of the coal pile exceeds the conveying height range of the rear conveyor; if the average height of the coal pile exceeds the maximum height of the conveyor transportation, increase the angle γ of the coal discharging mechanism to reduce the size of the coal discharging port, reduce the speed of the top coal falling, and reduce the height of the coal flow accumulation on the conveyor; if the difference between the average height of the coal pile and the maximum height of the conveyor transportation is large, reduce the angle γ of the coal discharging mechanism, increase the size of the coal discharging port, increase the speed of the top coal falling, and increase the height of the coal flow accumulation on the conveyor to make full use of the conveying capacity of the conveyor and save resources; at the same time, when adjusting the angle of the coal discharging mechanism, calculate and analyze the relative position between the coal discharging port and the conveyor through the above steps I and II, and through the position adjustment in step III, make the top coal discharged from the coal discharging mechanism accurately fall into the conveyor and the coal flow speed is appropriate.

[0171] The above is only the specific implementation manner of the present invention, and the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention.

Claims

1. A method for perceiving and controlling the relative position between a coal discharging mechanism and a rear conveyor, based on a system for perceiving and controlling the relative position between a coal discharging mechanism and a rear conveyor. The system includes a first inclination sensor, a second inclination sensor, a first displacement sensor, a second displacement sensor, a third displacement sensor, a data acquisition card, a host computer, a controller, and a solenoid valve; The first inclination sensor is arranged on the rear connecting rod, the second inclination sensor is arranged on the shield beam, the first displacement sensor is arranged on the tail beam jack, the second displacement sensor is arranged on the gob plate jack, and the third displacement sensor and the solenoid valve are arranged on the pulling jack; The first inclination sensor, the second inclination sensor, the first displacement sensor, the second displacement sensor, and the third displacement sensor are respectively connected to the host computer through the data acquisition card, and the host computer is connected to the solenoid valve through the controller; It is characterized in that This method includes the following steps: Ⅰ) Establish a perception model of the coal discharging position of the top coal caving support, and solve the relative position relationship between the coal discharging mechanism and the rear conveyor; Ⅱ) Through the position perception of the rear conveyor, judge whether the coal flow discharged by the coal discharging mechanism can accurately fall into the rear conveyor; Ⅲ) Adjust the relative position between the coal discharging mechanism and the rear conveyor to ensure that the coal flow on the coal discharging mechanism can fall into the rear conveyor to the greatest extent; Among them, the step Ⅰ) includes the following steps: A. On the support base, with the hinge point of the rear connecting rod and the base as the coordinate origin O, with the direction of the base length and pointing to the rear conveyor as the X-axis, and with the direction perpendicular to the base and pointing to the roof beam as the Y-axis, thus establishing a space coordinate system O-XY and defining it as a fixed coordinate system; B. Define relevant parameters and establish a model: L1 is the height from the base to the lower hinge point of the rear connecting rod; L2 is the length of the rear connecting rod; L3 is the distance from the hinge point of the tail beam jack on the shield beam to the hinge point of the shield beam and the tail beam; L4 is the length of the tail beam jack; L5 is the length of the tail beam; L6 is the length of the gob plate jack; L7 is the length of the pulling jack; L8 is the width of the rear conveyor; θ1 is the angle between the rear connecting rod and the X-axis; θ2 is the angle between the shield beam and the X-axis; θ3 is the fixed angle between the top surface of the shield beam and the connecting line between the hinge point of the tail beam jack on the shield beam and the hinge point of the shield beam and the tail beam; α is the angle between the connecting line between the hinge point of the shield beam and the tail beam and the hinge point of the tail beam jack on the shield beam and the X-axis; β is the angle between the tail beam and the X-axis; γ is the angle between the connecting line of the hinge points of the tail beam jack on the shield beam and the tail beam; C. In the coordinate system O-XY, solve the real-time position coordinates of the end point Q of the tail beam gob plate; (1) Solve the coordinates of the hinge point G of the shield beam and the tail beam in the coordinate system O-XY: X G = L2 cosθ1 Y G = L1 + L2 sinθ1 Write the coordinates of the G point in matrix form as: G = [L2cosθ1 L1 + L2sinθ1] T (1) (2) Establish a coordinate system O'-X'Y' at the G point and define it as a moving coordinate system; among them, the X'-axis always points to the end of the tail beam along the length direction of the support tail beam; the Y'-axis always points perpendicular to the tail beam to the roof; solve the coordinates of the end point Q of the gob plate in this coordinate system, and the solution is as follows: X' Q = L5 + L6 Y' Q ＝0 Write the coordinates of the Q point in matrix form as: Q = [L5 + L60] T (2) (3) Solve for the rotation matrix \(R\) and translation vector \(T\) used when converting a point in the moving coordinate system \(O'-X'Y'\) to the fixed coordinate system \(O-XY\) as follows: \(\angle FGN\) is the angle between point \(F\) on the upper surface of the support shield beam and the hinge point \(N\) of the shield beam-tail beam jack at the hinge point \(G\) of the shield beam and the tail beam. Define the magnitude of \(\angle FGN\) as \(\theta_3\); \(\theta_2\) is the angle between the shield beam and the \(X\)-axis. Then the angle between \(GN\) and the \(X\)-axis is: \(\alpha=\theta_3 - \theta_2\ (3)\) \(\angle FGN\) is the angle between the hinge point \(N\) of the shield beam-tail beam jack and point \(P\) on the tail beam at the hinge point \(G\) of the shield beam and the tail beam. Define its magnitude as \(\gamma\), and its magnitude changes with the length of the tail beam jack. \(\gamma\) can be obtained by the cosine theorem as: Then the angle \(\beta\) by which the moving coordinate system \(O'-X'Y'\) rotates about the rotation axis passing through point \(O\) and perpendicular to the plane of the fixed coordinate system \(O-XY\) can be solved as follows: \(\beta=\pi - \gamma - \alpha\ (5)\) Then the rotation matrix \(R\) of the moving coordinate system \(O'-X'Y'\) rotating about the rotation axis passing through point \(O\) and perpendicular to the plane of the fixed coordinate system \(O-XY\) can be obtained as: At the same time, from the coordinates of point \(G\) in the fixed coordinate system \(O-XY\) and the coordinates of point \(G\) in the moving coordinate system \(O'-X'Y'\), the translation vector \(T\) for converting the moving coordinate system \(O'-X'Y'\) to the fixed coordinate system \(O-XY\) can be obtained as: (4) Solve for the coordinate value of point \(Q\) in the fixed coordinate system \(O-XY\) as: Substitute the rotation matrix \(R\) and translation vector \(T\) obtained in step (3) to get: Then the \(X\)-axis coordinate of point \(Q\) in the fixed coordinate system \(O-XY\) can be obtained as: X Q = (L5 + L6) cosβ + L2 cosθ1 (10) Y Q = (L5 + L6)sinβ + L1 + L2 sinθ1 (11) Substitute equations (3), (4), and (5) into equations (10) and (11) to get: X Q 、Y Q are the coordinates of the end point Q of the tail beam insert plate in the fixed coordinate system O-XY.

2. The relative position sensing and control method of the coal discharging mechanism and the rear conveyor according to claim 1, characterized in that, The said step II) includes the following steps: (1) Calculate the position coordinates of the rear conveyor. Use the same fixed coordinate system \(O-XY\) as for calculating the position of the coal discharging mechanism, and solve for the coordinate values of the two end points \(W\) and \(V\) of the rear conveyor in the symmetry plane of the low-position top coal caving support; The coordinates of points \(W\) and \(V\) are: W = [L70] T (14) V = [L7 + L80] T (15) (2) Judge whether the coal flow can fall into the rear conveyor: Assume that the height of the coal flow falling along the coal discharging mechanism is \(h\). Assume that the coal flow falls vertically due to the action of gravity when it reaches the end point of the sluice gate. Then the \(X\)-axis coordinate range of the coal flow when it falls onto the rear conveyor is: X min = X Q (16) To enable the coal flow falling from the coal discharging mechanism to accurately fall into the rear conveyor, the following geometric constraints need to be satisfied simultaneously: X W <X min (18) X max <X V (19) Then from equations (14)-(19), we can get: As can be seen from Equation (20), whether the coal flow on the coal discharging mechanism can accurately fall into the rear conveyor is mainly related to the length L7 of the pulling jack; when the calculated X Q and L7 do not satisfy the above equation, it indicates that the coal flow cannot accurately fall into the rear conveyor. Then, it is necessary to adjust the length of the pulling jack L7 to make Equation (20) hold and enable the coal flow on the coal discharging mechanism to accurately fall into the rear conveyor.

3. The relative position sensing and control method of the coal discharging mechanism and the rear conveyor according to claim 1, characterized in that The said step III) includes the following steps: By solving the relative position between the coal discharging mechanism and the rear conveyor, it can be known that when the magnitude of the X value L7 of the W point coordinate on the rear conveyor is closer to the magnitude of the X value X of the Q point coordinate at the end of the tail beam insertion plate and L7 < X Q , the coal flow can fall into the rear conveyor to the greatest extent. Therefore, the control target is determined as: L7 = X Q ; Q ; Select the PID control method to adjust the relative position of the coal discharging mechanism and the rear conveyor as follows: According to the actual control requirements, define the input function of the PID controller as: e(t) = X Q -L7 (21) Where: \(e(t)\) is the input of the controller; \(u(t)\) is the output of the controller; \(y(t)\) is the output of the system; Then the output of the PID controller can be obtained as: Where: K P is the proportionality coefficient, selected according to the model of the pulling jack; T i is the integral constant coefficient, selected according to the model of the pulling jack; T d is the differential constant coefficient, selected according to the model of the pulling jack; The specific working process is as follows: After the controller obtains the input e(t) formed by the difference between the value of X calculated by the host computer and the length L7 of the pulling jack measured by the displacement sensor, it outputs the corresponding control signal u(t) to the solenoid valve of the pulling jack through the PID controller to control the opening and closing and the position of the solenoid valve, and then controls the hydraulic oil to enter the column cavity to make the pulling jack extend, or releases the hydraulic oil in the column cavity to make the pulling jack shorten; The adjusted length L7 of the pulling jack can be measured in real time through the displacement sensor, and the difference between X Q and L7 is calculated. If it is not equal to 0, the control process continues to be adjusted; thereby realizing the real-time adjustment of the relative position between the coal discharging mechanism and the rear conveyor, so that the coal flow on the coal discharging mechanism can fall into the rear conveyor to the greatest extent. Q ​ 4. The relative position sensing and control method of the coal discharging mechanism and the rear conveyor according to claim 1, characterized in that It also includes step IV) correcting the error of the coal discharging position. Through visual perception, finely adjust the relative position of the coal discharging mechanism and the rear conveyor, including the following steps: The camera of the first visual monitoring device takes pictures of the coal flow position accumulation and transmits the pictures to the image processing device. The image processing device processes the pictures, measures the distance between the first positioning mark point and the second positioning mark point, and compares it with the actual distance between the first positioning mark point and the second positioning mark point to obtain the picture scale. At the same time, measure the straight-line distance between the first positioning mark point in the picture and the midpoint of the bottom of the coal pile, and multiply it by the scale to obtain the actual distance between the first positioning mark point and the coal pile. By separately measuring and calculating the distances from the first positioning mark point to the coal pile in two pictures transmitted by the camera at an interval of 1.5 s, denoted as S1 and S2; judge whether the relative position of the first positioning mark point and the coal pile has changed. If S1 = S2, it indicates that the position of the coal pile has not changed relative to the first positioning mark point, which means that the coal discharge port and the rear conveyor are not aligned, that is, the coal pile fails to accurately fall on the rear conveyor. The top coal discharged from the coal discharge mechanism falls outside the conveyor and cannot be safely transported by the rear conveyor. Position adjustment between the coal discharge mechanism and the rear conveyor is required. If S1 ≠ S2, it indicates that the position of the coal pile has changed relative to the first positioning mark point. Further calculate the product of the translation speed of the rear conveyor scraper and the interval time, denoted as S3. If S2 = S3, it indicates that the coal pile has fallen completely and accurately on the conveyor and is safely transported by the conveyor. The second visual monitoring device installed on the rear connecting rod is used to judge whether the coal discharge speed is reasonable. By measuring the height of the coal flow accumulation on the conveyor to judge whether the coal discharge speed of the coal discharge mechanism is reasonable at this time; the camera takes pictures of the coal flow accumulation on the conveyor every 0.5 s and transmits the pictures to the image processing device at the rear for processing. The image processing device sharpens the image, performs image recognition, and measures the straight-line distance between the first positioning mark point and the second positioning mark point in the image, and compares it with the actual distance between the two points to obtain the scale in the image. At the same time, measure the height of each coal pile in the picture and take the average value. Convert the average height of the coal pile through the scale to obtain the actual average height of the coal pile, and compare whether the average height of the coal pile exceeds the conveying height range of the rear conveyor; if the average height of the coal pile exceeds the maximum height of the conveyor transportation, increase the angle γ of the coal discharge mechanism to reduce the size of the coal discharge port, reduce the speed of the top coal discharge, and reduce the height of the coal flow accumulation on the conveyor; if the difference between the average height of the coal pile and the maximum height of the conveyor transportation is large, reduce the angle γ of the coal discharge mechanism, increase the size of the coal discharge port, increase the speed of the top coal discharge, and increase the height of the coal flow accumulation on the conveyor; at the same time, when adjusting the angle of the coal discharge mechanism, calculate and analyze the relative position of the coal discharge port and the conveyor through the above steps I and II, and through the position adjustment in step III, make the top coal discharged from the coal discharge mechanism accurately fall into the conveyor, and the coal flow speed is appropriate.

Images