Mining belt conveyor self-moving tail position and posture leveling control method

Abstract

The invention relates to the technical field of self-moving tail leveling, and discloses a mine belt conveyor self-moving tail position and posture leveling control method which comprises the following steps that the pitch angle in the length direction and the roll angle in the width direction of a self-moving tail are collected; with the supporting height of one hydraulic cylinder of the self-moving tail as a reference datum, the pitch angle and the distance between the two hydraulic cylinders in the length direction of the self-moving tail are used for calculating the pitch correction amount; the rolling correction amount is calculated according to the rolling angle and the distance between the two hydraulic cylinders in the width direction of the self-moving machine tail; calculating the total relative height deviation of each hydraulic cylinder supporting point relative to the reference point by adopting a linear superposition mode according to the pitching correction and the rolling correction; according to all the total relative height deviations, the height adjusting amount of all the hydraulic cylinders relative to the reference quantity is calculated; according to the method, the control algorithm is simplified, the calculation redundancy is reduced, the leveling response speed is increased, and the stability and safety of coal transportation are guaranteed.

Description

Technical Field

[0001] This invention relates to the field of self-moving tail leveling technology, and in particular to a method for controlling the position and attitude leveling of the self-moving tail of a mining belt conveyor based on displacement and dual-axis tilt sensors. Background Technology

[0002] In underground coal mining operations, belt conveyors are the core material conveying equipment. Self-moving tail sections, as key supporting devices, integrate functions such as self-movement, deviation adjustment, and height adjustment. They can adapt to the frequent position adjustment needs of the coal mining face and achieve coordinated operation with transfer machines. They are an important component of modern high-yield and high-efficiency fully mechanized mining faces.

[0003] However, the underground environment of coal mines is complex. Affected by factors such as undulating coal seams, uneven floors, and uneven loads, self-propelled conveyors are prone to longitudinal pitch, lateral offset, and compound torsion during tail-mounted propulsion. As a heavy-duty platform, its positional stability directly affects the coordinated operation of the belt conveyor and transfer conveyor. Deviations not only exacerbate belt misalignment and wear, reducing conveying efficiency, but may also cause safety hazards such as equipment jamming and material spillage, hindering the improvement of intelligent mining levels in coal mines.

[0004] Existing leveling technologies are mainly divided into two categories: position error control and angle error control. However, neither strategy alone can meet the complex operating conditions of a self-propelled tail section, resulting in problems such as insufficient leveling accuracy and response lag. Furthermore, traditional solutions cannot fully reflect the spatial distortion state; the control logic often employs step-by-step serial leveling, which is prone to coupling interference; and the control algorithms are mostly simple threshold feedback, lacking precise mathematical model support, leading to significant leveling errors.

[0005] In summary, existing technologies suffer from limitations such as incomplete monitoring, logical coupling, and insufficient accuracy, failing to meet the demands for rapid, accurate, and stable leveling of self-moving tail sections under complex underground working conditions. Developing a more adaptable leveling method is crucial for improving the level of intelligent coal mining. Summary of the Invention

[0006] This invention proposes a self-moving tail position and attitude leveling control method for mining belt conveyors to address the shortcomings of the prior art. This method simplifies the control algorithm, reduces computational redundancy, improves the leveling response speed, and solves the problems of poor adaptability and insufficient accuracy of existing leveling methods, thus ensuring the stability and safety of coal transportation.

[0007] The technical solution of this invention is: a method for controlling the self-moving tail position and posture of a mining belt conveyor, comprising the following steps: The pitch angle along the length of the moving tail and the roll angle along the width were collected. Using the support height of one of the hydraulic cylinders of the self-propelled tail as a reference, the pitch correction is calculated using the sine of the pitch angle and the distance between the two hydraulic cylinders in the length direction of the self-propelled tail; the roll correction is calculated using the sine of the roll angle and the distance between the two hydraulic cylinders in the width direction of the self-propelled tail. The total relative height deviation of each hydraulic cylinder support point relative to the reference point is calculated by linear superposition of the pitch correction and roll correction. Based on the total relative height deviation, calculate the height adjustment amount of each hydraulic cylinder relative to the reference reference. Adjust each hydraulic cylinder according to the height adjustment amount to achieve leveling of the self-moving tail.

[0008] In at least one embodiment of the present invention, when collecting the pitch angle and roll angle of the self-propelled tail, the data is collected by installing a dual-axis tilt sensor at one of the diagonal positions of the self-propelled tail.

[0009] In at least one embodiment of the present invention, a displacement sensor is installed on each of the hydraulic cylinders of the self-moving tail section. Each displacement sensor is used to monitor the displacement data of each hydraulic cylinder in real time to verify the execution accuracy of the system.

[0010] In at least one embodiment of the present invention, when selecting a reference reference, the hydraulic cylinder with the smallest support height is selected as the reference reference based on the total relative height deviation of each hydraulic cylinder.

[0011] In at least one embodiment of the present invention, the hydraulic cylinder serving as a reference during the leveling process does not participate in height adjustment.

[0012] In at least one embodiment of the present invention, during the leveling control execution, the four hydraulic cylinders are independently controlled by an integrated electro-hydraulic control valve group, wherein the integrated electro-hydraulic control valve group is an intrinsically safe valve group for mining.

[0013] In at least one embodiment of the present invention, the total relative height deviation of each hydraulic cylinder is a linear superposition of pitch correction and roll correction based on the position of the hydraulic cylinder, and the total relative height deviation of the reference hydraulic cylinder is 0.

[0014] In at least one embodiment of the present invention, a PLC controller is used for leveling control. The PLC controller is connected to an electro-hydraulic proportional pilot valve through a proportional amplifier. The electro-hydraulic proportional pilot valve controls the main directional valve to drive the hydraulic cylinder to extend and retract, forming a closed-loop control system of "sensing-computing-execution".

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. The bidirectional decoupled superposition leveling strategy proposed in this invention decomposes the overall tilt of the conveyor body into two independent components: longitudinal pitch and lateral roll. This avoids complex quadrant judgments and simplifies the control algorithm by linearly superimposing the height deviation, reducing computational redundancy and improving the leveling response speed. This method is applicable to various working conditions where the conveyor body has both longitudinal pitch and lateral roll tilts, exhibiting strong adaptability. It can be widely applied to the self-moving tail section of mining belt conveyors based on four supporting hydraulic cylinders, effectively solving the problems of poor adaptability and insufficient accuracy of existing leveling methods, and ensuring the stability and safety of coal transportation.

[0016] 2. This invention, based on the fusion monitoring of dual-axis tilt sensors and displacement sensors, can acquire real-time and accurate data on the tilt angle and hydraulic cylinder displacement, providing a reliable basis for height deviation calculation and adjustment determination, ensuring leveling accuracy. Simultaneously, the leveling process follows the principle of high-position contraction, achieving leveling solely through hydraulic cylinder contraction, avoiding the stability risks that may arise from extension operations, and minimizing the overall height of the machine body, fully adapting to the space requirements and safety regulations of downhole operations. Attached Figure Description

[0017] Figure 1 This is a flowchart of the method of the present invention; Figure 2 This is a schematic diagram of the sensor installation of the present invention; Figure 3 This is a schematic diagram of the overall structure of the mining belt conveyor of the present invention.

[0018] Explanation of reference numerals in the attached figures: 1. Hydraulic cylinder; 2. Dual-axis tilt sensor; 3. Displacement sensor; 4. Tail frame; Detailed Implementation

[0019] The accompanying drawings in this invention are not strictly drawn to scale, and the specific dimensions and quantity of each structure can be determined according to actual needs. The drawings described in this invention are merely structural schematic diagrams.

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the described embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0022] Existing leveling technologies are mainly divided into two categories: position error control and angle error control. However, neither strategy alone can meet the complex operating conditions of a self-propelled tailplane, resulting in problems such as insufficient leveling accuracy and response lag. Furthermore, traditional solutions often employ single-point sensor placement, failing to comprehensively reflect spatial distortion. Control logic frequently uses step-by-step serial leveling, which is prone to coupling interference. Altitude strategies based on initial altitude recovery may cause the fuselage's center of gravity to shift upwards. Control algorithms are often based on simple threshold feedback, lacking precise mathematical model support, leading to significant leveling errors.

[0023] In summary, existing technologies suffer from shortcomings such as limited monitoring, logical coupling, insufficient accuracy, and poor stability, failing to meet the demands for rapid, accurate, and stable leveling of self-moving tail sections under complex underground working conditions. Developing a more adaptable leveling method is crucial for improving the level of intelligent coal mining.

[0024] This invention addresses the pose deviation problem caused by low efficiency of manual control and lag of traditional control strategies in complex downhole working conditions. With the core objective of constructing a dynamic pose control model, it overcomes the limitations of existing methods that rely on high-precision sensors and offline simulation through a multi-sensor fusion monitoring scheme, aiming to achieve real-time and accurate adjustment of the pose of the self-moving tail.

[0025] Combination Figures 1 to 3 As shown, a method for self-moving tail position leveling control of a mining belt conveyor includes the following steps: Pitch angle collected along the length of the moving tail section and roll angle in the width direction ; Using the support height of one of the hydraulic cylinders of the self-propelled tail section as a reference (in this embodiment, hydraulic cylinder A is used as the physical reference), and considering the pitch angle α and the distance between the two hydraulic cylinders along the length of the self-propelled tail section... Calculate pitch correction ; with roll angle The distance between the two hydraulic cylinders in the width direction of the self-propelled machine tail section Calculate the roll correction amount Specifically, the calculation formula is as follows: Based on pitch correction and roll correction amount The total relative height deviation of each hydraulic cylinder support point relative to the reference point is calculated using a linear superposition method. This deviation is a linear superposition of the two components mentioned above, and the deviations of each hydraulic cylinder are shown below: Based on the total relative height deviation Calculate the height adjustment amount of each hydraulic cylinder relative to the reference reference. Based on the adjustment amount at each height Adjust each hydraulic cylinder to achieve leveling of the self-moving tail section. To minimize the machine's height, the system selects the maximum value from the four deviation values ​​mentioned above. Final contraction adjustment amount of each hydraulic cylinder The calculation is shown in the formula:

[0026] Under this logic If the value is 0, it remains stationary; if the value of the remaining hydraulic cylinders is 0, it remains stationary. All values ​​are negative, representing the distance the hydraulic cylinder needs to retract. As an alternative embodiment, when collecting the pitch and roll angles of the self-propelled tail section, dual-axis tilt sensors are installed at one of the diagonal points on the self-propelled tail section for data acquisition. A dual-axis tilt sensor is a sensor used to measure the tilt angle of an object on a horizontal plane. It can simultaneously measure the tilt angle of an object in both horizontal and vertical directions, and is therefore widely used in industrial automation, construction engineering, aerospace, and other fields. Figure 2 The dual-axis tilt sensor shown is installed diagonally at point AC.

[0027] As an alternative embodiment, displacement sensors are installed on each hydraulic cylinder of the self-propelled tail section. Each displacement sensor is used to monitor the displacement data of each hydraulic cylinder in real time to verify the system's execution accuracy. Specifically, each displacement sensor monitors the displacement data of each supporting hydraulic cylinder in real time, providing direct monitoring data for the machine's height status; through real-time calculation of spatial coordinate changes, the height difference of the machine under different coordinates is obtained, providing basic data support for leveling control and assisting in judging the machine's tilt status.

[0028] As an alternative embodiment, when selecting the reference reference, the hydraulic cylinder with the smallest support height is selected, and the hydraulic cylinder that serves as the reference reference does not participate in height adjustment during the leveling process; when the leveling control is executed, the four hydraulic cylinders are independently controlled through an integrated electro-hydraulic control valve group.

[0029] As an alternative embodiment, it is applicable to self-moving tail structures based on four hydraulic cylinders, and can adapt to various working conditions where the machine body has longitudinal pitch tilt and lateral roll tilt. It achieves precise leveling through unified deviation calculation and adjustment logic.

[0030] To verify the effectiveness of the leveling strategy under different working conditions, this invention designed three typical test conditions based on the real-time height distribution characteristics of the four supporting hydraulic cylinders (A, B, C, and D) of the self-moving tail section. The leveling strategy is shown in Table 1. Single-sided tilt condition: Simulating the effect of lateral unevenness of the tunnel floor, the machine body tilts along the X-axis (left-right direction). Height characteristics: Displacement sensor data shows that the extension length of the left support points (A, D) of the machine body is significantly greater than that of the right side (B, C), i.e., Δa≈Δd>Δb≈Δc. At this time, the machine body presents a "right-high, left-low" posture, and the left side sinks relatively.

[0031] Pitch and Tilt Condition: Simulating changes in the slope of the tunnel or single-end elevation of the machine head / tail, causing the machine body to tilt longitudinally along the Y-axis (forward and backward direction). Height Characteristics: Displacement sensor data shows that the height of the front support points (A, B) of the machine body is significantly higher than that of the rear support points (C, D), i.e., Δa≈Δb>Δc≈Δd. At this time, the machine body is in a tilted-up climbing posture.

[0032] Composite torsional condition: Simulates a multi-degree-of-freedom coupled condition downhole, where the machine body simultaneously pitches and rolls. Height characteristics: The heights at the four points are non-coplanar. For example, if the machine body tilts severely towards point D, the hydraulic cylinder height at point D will be the lowest, i.e., Δb>Δc>Δa>Δd.

[0033] Table 1. Typical Operating Condition Leveling Strategies The self-moving tail leveling control logic of this invention: The system uses dual-axis tilt sensors mounted on diagonal hydraulic cylinders. These sensors can capture real-time attitude deviation data such as pitch and roll angles of the platform relative to an ideal horizontal plane. By arranging them diagonally, the overall tilt state can be reflected more comprehensively.

[0034] The tilt angle data acquired in real time is then transmitted to the system's leveling algorithm module, which uses a mathematical model to calculate the ideal displacement that each hydraulic cylinder needs to adjust in order to eliminate the current attitude deviation, so that the entire platform can reach a level state.

[0035] Furthermore, the system is equipped with displacement sensors in each hydraulic cylinder to provide real-time feedback on the current extension and retraction length of the hydraulic cylinder, and the feedback data is compared with the target displacement calculated by the leveling algorithm.

[0036] Finally, the system transmits the deviation signal to the controller. The controller adjusts the flow and pressure of the hydraulic oil, controlling the extension and retraction of the hydraulic cylinders to restore the entire platform to the preset level state, thus completing the leveling task.

[0037] Hydraulic component execution process: For the precision control of the hydraulic cylinder adjustment required for leveling the tail of the self-propelled machine, the control process involves the PLC first outputting the target adjustment amount of the hydraulic cylinder determined by the leveling algorithm, and then amplifying the corresponding current signal through a proportional amplifier before transmitting it to the intrinsically safe switching valve for mining. Based on the linear mapping relationship between current and pressure, the PLC outputs a matching control hydraulic pressure to drive the main directional valve core to precisely reach the target opening position. Simultaneously, the valve core displacement feedback signal is sent back to the PLC to correct the control current in real time, ensuring a linear match between the high-pressure emulsion flow rate and the hydraulic cylinder's extension and retraction speed and stroke. Ultimately, this achieves precise execution of the hydraulic cylinder adjustment amount required for leveling (control error ≤ 0.5mm). The specific process is as follows: The PLC outputs a corresponding current signal based on the adjustment amount of the target hydraulic cylinder, which is then amplified by a proportional amplifier and transmitted to the intrinsically safe electro-hydraulic proportional pilot valve for mining. The switching valve, combined with valve core displacement feedback closed-loop control, moves the main directional valve core to the target opening. The main valve outputs high-pressure emulsion with a matching flow rate according to the opening size, and controls the hydraulic cylinder to complete the extension and retraction action according to the leveling requirements, so as to achieve precise implementation of the adjustment amount.

[0038] Analysis of the self-moving tail leveling effect: 1. Typical working condition leveling simulation experiment This invention uses a 3D model of a self-propelled tail section as a basis, reconstructing the length and width parameters of the fuselage and the assembly relationships of various components. Targeted simulation schemes are designed for typical complex downhole working conditions. By setting conditions such as unilateral tilt, pitch tilt, and combined torsion, the self-propelled tail section's attitude leveling method is simulated. During the simulation, extension and retraction displacement data of each hydraulic cylinder are collected, and the stability of the attitude leveling method under different working conditions is analyzed, providing data support and theoretical basis for subsequent laboratory tests and field applications.

[0039] (1) Single-sided tilting condition Horizontal offset (X direction) working condition description: The platform tilts along the X-axis (left and right direction), and the right side sinks. The displacements of the four hydraulic cylinders ABCD are 0mm, 105mm, 105mm, and 0mm, respectively.

[0040] Leveling logic: A positive angle on side AB indicates that point B is higher than point A; a negative angle on side CD (left side) indicates that point C is lower than point D. The reference point is selected as the lowest point (A or D), and the height of hydraulic cylinder BC is reduced to balance the height difference; the leveling results for the single-sided tilt condition are shown in Table 2.

[0041] Table 2 Leveling Results under Single-Sided Tilt Condition (2) Pitching and tilting conditions Horizontal offset (Y direction) working condition description: The platform tilts along the Y-axis (front and back direction) and rises on one side.

[0042] The displacements of the four hydraulic cylinders ABCD are 0mm, 0mm, 24.42mm, and 24.42mm, respectively.

[0043] Leveling logic: A negative angle for side AD (front end) indicates that point D is lower than point A; a positive angle for side BC (rear end) indicates that point C is higher than point B. The reference point is point A. The height of hydraulic cylinder CD is lowered to balance the height difference. The leveling results under pitch and tilt conditions are shown in Table 3.

[0044] Table 3 Leveling Results under Pitch and Tilt Conditions (3) Composite torsion condition Complex working conditions under multiple degrees of freedom deviation: The platform tilts towards point A, resulting in height differences between the four pillars. The displacements of the four hydraulic cylinders A, B, C, and D are 4.36 mm, 25.26 mm, 0 mm, and 9.61 mm, respectively.

[0045] Leveling logic: First, lower hydraulic cylinder D until it is level with point C. At this point, the tail section is approximately in a pitching / tilting state. Then, lower hydraulic cylinders A and B until they are level with C and D to complete the leveling. The leveling results under the compound torsion condition are shown in Table 4.

[0046] Table 4. Leveling Results under Composite Torsion Condition In summary, relevant tests have demonstrated that the technical solution of this invention is highly adaptable and can effectively cope with typical working conditions such as unilateral tilt, pitch tilt, and compound torsion. It has the advantages of fast response, high accuracy, and strong stability, and solves the defects of traditional leveling methods such as one-sided monitoring, logical coupling, and insufficient accuracy. It can be directly applied to heavy-load and complex working conditions in underground coal mines and has important engineering application value for improving the level of intelligent mining in coal mines.

[0047] The above embodiments are merely specific implementations of the present invention, used to illustrate the technical solutions of the present invention, and not to limit them. The protection scope of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the technical scope disclosed in the present invention, or make equivalent substitutions for some of the technical features; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions implemented in the present invention, and should all be covered within the protection scope of the present invention.

Claims

1. A method for controlling the self-moving tail position and leveling of a mining belt conveyor, characterized in that, Includes the following steps: The pitch angle along the length of the moving tail and the roll angle along the width were collected. Using the support height of one of the hydraulic cylinders of the self-propelled tail as a reference, the pitch correction is calculated using the sine of the pitch angle and the distance between the two hydraulic cylinders in the length direction of the self-propelled tail; the roll correction is calculated using the sine of the roll angle and the distance between the two hydraulic cylinders in the width direction of the self-propelled tail. The total relative height deviation of each hydraulic cylinder support point relative to the reference point is calculated by linear superposition of the pitch correction and roll correction. Based on the total relative height deviation, calculate the height adjustment amount of each hydraulic cylinder relative to the reference reference. Adjust each hydraulic cylinder according to the height adjustment amount to achieve leveling of the self-moving tail.

2. The method for self-moving tail position leveling control of a mining belt conveyor as described in claim 1, characterized in that, When collecting the pitch and roll angles of the self-moving tail, dual-axis tilt sensors are installed at one of the diagonal points of the self-moving tail for data acquisition.

3. The method for self-moving tail position leveling control of a mining belt conveyor as described in claim 1, characterized in that, Displacement sensors are installed on each of the hydraulic cylinders at the tail of the self-propelled machine, and each displacement sensor is used to monitor the displacement data of each hydraulic cylinder in real time.

4. The method for self-moving tail position and attitude leveling control of a mining belt conveyor as described in claim 1, characterized in that, When selecting the reference benchmark, the hydraulic cylinder with the smallest support height is selected as the reference benchmark based on the total relative height deviation of each hydraulic cylinder.

5. The method for self-moving tail position leveling control of a mining belt conveyor as described in claim 1, characterized in that, During the leveling process, the hydraulic cylinder that serves as the reference point does not participate in height adjustment.

6. The method for self-moving tail position leveling control of a mining belt conveyor as described in claim 1, characterized in that, During the leveling control execution, the four hydraulic cylinders are independently controlled by an integrated electro-hydraulic control valve group, which is an intrinsically safe valve group for mining.

7. The method for self-moving tail position leveling control of a mining belt conveyor as described in claim 1, characterized in that, The total relative height deviation of each hydraulic cylinder is a linear superposition of the pitch correction and roll correction based on the position of the hydraulic cylinder, and the total relative height deviation of the reference hydraulic cylinder is 0.

8. The method for self-moving tail position leveling control of a mining belt conveyor as described in claim 1, characterized in that, A PLC controller is used for leveling control. The PLC controller is connected to an electro-hydraulic proportional pilot valve through a proportional amplifier. The electro-hydraulic proportional pilot valve controls the main directional valve to drive the hydraulic cylinder to extend and retract.

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