Steeply inclined coal seam working face equipment group cooperative intelligent control method

Abstract

The present application relates to the technical field of mechanized mining of steeply inclined coal seams, and discloses a kind of steeply inclined coal seam working face equipment group cooperative intelligent control method;The method comprises: calculating the gravitational potential energy power of the collected working condition data of coal mining machine and the sliding force and spatial gradient of hydraulic support, and solving the traction speed curve to control the operation of coal mining machine;Identify the sliding force accumulation point, and screen the main anchor support and the slave anchor support;Control the main anchor support to enter the anchoring state, and control the slave anchor support to execute the pressure shifting support in turn;During the pressure shifting support, when the cumulative displacement of the downward sliding exceeds the displacement threshold, a step-by-step pressure relief operation from bottom to top is performed;The present application realizes the dynamic cooperative control of coal mining machine and hydraulic support group under steeply inclined working condition, not only inhibits the speed oscillation and energy consumption of coal mining machine, but also enhances the ability of hydraulic support group to resist sliding force, thereby preventing the overall downward sliding and chain toppling accident of support, and improving the running stability and service life of equipment group.

Description

Technical Field

[0001] This invention relates to the field of mechanized mining technology for steeply inclined coal seams, specifically to a collaborative intelligent control method for equipment groups in a steeply inclined coal seam working face. Background Technology

[0002] Steeply inclined coal seams account for a significant share of coal resource reserves. Due to their unique spatial orientation, their mining operations face extremely complex working conditions that differ from those of gently inclined or near-horizontal coal seams.

[0003] In fully mechanized mining of steeply inclined coal seams, the three-machine equipment group consisting of the coal mining machine, scraper conveyor, and hydraulic support is the core carrier for integrated operations of coal breaking, coal transportation, and roof support. It needs to be precisely coordinated to complete continuous operations such as coal cutting, support shifting, and conveyor pushing. Due to the large dip angle of the coal seam, the three-machine equipment group is in an inclined posture as a whole. The tangential component of the equipment's own weight along the dip of the coal seam is significantly increased. It also needs to withstand multiple loads such as the self-weight of the roof strata, the stress of the surrounding rock, and mining disturbances, forming a complex dynamic coupling mechanical environment. This places extremely high demands on the coordinated control accuracy and operational stability of the three-machine equipment group. Its operating status directly determines the mining efficiency, operational safety, and equipment service life.

[0004] Currently, control systems for steeply inclined working faces mostly adopt the control strategy for gently inclined coal seams, that is, the coal mining machine adopts a constant speed operation mode or a simple PID speed regulation method based on the cutting current, and the hydraulic supports perform group support shifting or automatic support shifting operation in a fixed sequence. However, this type of control strategy has certain limitations when applied to steeply inclined working conditions: during the downward operation of the coal mining machine, the traction speed is prone to frequent oscillations or even overspeeding; during the upward operation, there will be problems such as a sharp increase in traction force, significant mechanical impact, and high energy consumption. Moreover, the above operating conditions will accelerate the fatigue damage of key components such as traveling wheels and chains, reducing the reliability of equipment operation. The load borne by the hydraulic support group is unevenly distributed along the coal seam dip and is dynamically adjusted in real time with the change of the coal mining machine's operating position. The fixed support strength and uniform support shifting sequence can easily lead to a continuous accumulation of load on some sections of the support, which can easily cause accidents such as the overall slippage of the support group, support seizure, or even support collapse under long-term action. In addition, there is a lack of effective coordination mechanism between the speed regulation behavior of the coal mining machine and the support shifting action of the hydraulic support, resulting in insufficient overall operational stability of the three-machine equipment group, which in turn significantly shortens the service life of the equipment and restricts the efficient and safe mining of steeply inclined working faces.

[0005] The information disclosed in this background section is intended only to enhance the understanding of the overall background of this application and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0006] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a collaborative intelligent control method for equipment groups in steeply inclined coal seam working faces, which solves the problems mentioned in the background technology to a certain extent, suppresses the speed oscillation and energy consumption of coal mining machines, enhances the ability of hydraulic support groups to resist slippage forces, and thus improves the operational stability and service life of the equipment group.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: This invention provides a collaborative intelligent control method for equipment groups in steeply inclined coal seam working faces, comprising the following steps: Real-time acquisition of working condition data of coal mining machine and hydraulic support, and calculation of the gravitational potential energy power of coal mining machine and the sliding force and spatial gradient along the dip of each hydraulic support based on the working condition data; Based on the gravitational potential power and spatial gradient, the traction speed curve of the coal mining machine along the working face is solved, and the operation of the coal mining machine is controlled by the traction speed curve. Based on the sliding force of each hydraulic support and its spatial gradient along the dip, the sliding force accumulation point is identified, and the main anchor support and the secondary anchor support are selected in combination with the preset screening rules. After the coal mining machine starts running, the upstream secondary anchor supports of the main anchor support are controlled to perform pressurized frame shifting in sequence; when the coal mining machine is at a preset distance from the main anchor support, the main anchor support is controlled to enter the anchoring state, and after the main anchor support enters the anchoring state, the downstream secondary anchor supports of the main anchor support are controlled to perform pressurized frame shifting in sequence. During the pressurized relocation process, the cumulative downward displacement of the hydraulic support group is monitored in real time. When the cumulative downward displacement exceeds the preset displacement threshold, a bottom-up depressurization operation is performed.

[0008] As a preferred embodiment of the collaborative intelligent control method for equipment groups in a steeply inclined coal seam working face as described in this application, the calculation methods for the sliding force of each hydraulic support and its spatial gradient along the dip direction are as follows: Establish the static equilibrium equation for any hydraulic support, and based on the column pressure, balancing jack pressure, support tilt angle and corresponding local tilt angle of the corresponding hydraulic support, solve the static equilibrium equation to obtain the sliding force of the corresponding hydraulic support. Along the dip of the working face, the sliding forces of each hydraulic support are arranged sequentially from the head to the tail of the machine according to their support numbers to obtain the sliding force sequence; By performing a differential operation on the sliding force sequence, the spatial gradient of the sliding force of each hydraulic support along the dip direction is obtained.

[0009] As a preferred embodiment of the collaborative intelligent control method for equipment groups in a steeply inclined coal seam working face described in this application, the traction speed curve is solved as follows: Based on the gravitational potential energy power of the coal mining machine, the sliding force growth rate of each hydraulic support behind the coal mining machine is calculated. Starting from the current position of the coal mining machine, along the direction of the coal mining machine's travel, the preset prediction window length in front is divided into N equally spaced discrete points; N is the number of discrete points. For any discrete point, determine the set of hydraulic supports within the effective working distance behind it, and calculate the maximum speed of each hydraulic support in the set of hydraulic supports at each discrete point based on the slip force growth rate. With the maximum speed as a constraint, and with the optimization objectives of minimizing the deviation between the traction speed and the rated speed of the coal mining machine and minimizing the fluctuation amplitude of gravitational potential power between adjacent discrete points, an objective function is constructed. The objective function is solved using numerical optimization methods to obtain the traction speed curve within the prediction window length.

[0010] As a preferred embodiment of the collaborative intelligent control method for equipment groups in a steeply inclined coal seam working face as described in this application, the sliding force growth rate is obtained by adding the natural term and the coal mining machine drive term; For each hydraulic support, the gravitational potential energy power of the coal mining machine as it passes the corresponding hydraulic support is collected in Q consecutive coal mining cycles, and the sliding force of the corresponding hydraulic support is continuously recorded; Q is a positive integer. The sliding force of the hydraulic support is numerically differentiated to obtain the sliding force growth rate sequence; the gravitational potential energy power of the coal mining machine when passing the corresponding hydraulic support is multiplied by the growth coefficient to obtain the coal mining machine drive term of the corresponding hydraulic support. The slip force growth rate sequence is used as the output, and the sum of the coal mining machine drive term and the natural term after propagation delay is used as the input. The natural term and growth coefficient are calculated by fitting.

[0011] As a preferred embodiment of the collaborative intelligent control method for equipment groups in a steeply inclined coal seam working face described in this application, the calculation steps for the maximum speed are as follows: For any discrete point, determine the growth rate threshold of each hydraulic support in the set of hydraulic supports corresponding to the discrete point, and calculate the difference between the growth rate threshold and the corresponding natural term; calculate the ratio of the difference to the corresponding growth coefficient to obtain the allowable gravitational potential energy power threshold of the corresponding hydraulic support. Extract the minimum value of the allowable gravitational potential energy power threshold of all hydraulic supports in the set of hydraulic supports corresponding to any discrete point, and obtain the maximum allowable gravitational potential energy power of the corresponding discrete point. Calculate the cumulative product of the coal mining machine's mass, gravitational acceleration, and local inclination angle at any discrete point, and calculate the ratio of the maximum allowable gravitational potential power at the corresponding discrete point to the cumulative product to obtain the maximum velocity at the corresponding discrete point.

[0012] As a preferred embodiment of the collaborative intelligent control method for equipment groups in steeply inclined coal seam working faces described in this application, the objective function is constructed as follows: Calculate the difference between the traction speed and the rated speed of the coal mining machine to obtain the first difference; calculate the gravitational potential power at each discrete point, and calculate the difference between the gravitational potential power between adjacent discrete points to obtain the second difference; Calculate the square of the ratio of the second difference to the interval of adjacent discrete points to obtain the first squared value, and calculate the square of the first difference to obtain the second squared value; perform a weighted summation of the first squared value and the second squared value to obtain the objective function.

[0013] As a preferred embodiment of the collaborative intelligent control method for equipment groups in a steeply inclined coal seam working face as described in this application, wherein: when the spatial gradient of the sliding force at any hydraulic support is greater than 0 and the absolute value is greater than a preset gradient threshold, the location of the corresponding hydraulic support is set as the sliding force accumulation point; The steps of selecting the main anchor support and the secondary anchor support based on preset screening rules specifically include: For each identified point of slip force accumulation, the first hydraulic support in its downstream direction is selected as the candidate main anchor support. If the distance between any two adjacent sliding force accumulation points is less than the preset spacing threshold, then the candidate main anchor support of the sliding force accumulation point further downstream of the corresponding two adjacent sliding force accumulation points will be taken as the main anchor support. If the distance between all adjacent slip force accumulation points is greater than or equal to the spacing threshold, then the candidate main anchor support for each slip force accumulation point is taken as the corresponding main anchor support. All hydraulic supports except the main anchor support are set as secondary anchor supports; the main anchor support is updated once every coal mining cycle.

[0014] As a preferred embodiment of the collaborative intelligent control method for equipment groups in a steeply inclined coal seam working face described in this application, the specific method of pressurized frame movement is as follows: For the secondary anchor support upstream of the main anchor support, when the coal mining machine passes over it, the corresponding secondary anchor support immediately performs a support shifting action, and during the shifting process, the column pressure is maintained within the corresponding pressure range; The pressure range is a preset proportion that is greater than or equal to the rated pressure of the corresponding hydraulic support column. After the coal mining machine passes the main anchor support and the main anchor support has entered the anchoring state, the movement of the downstream auxiliary anchor supports downstream of the main anchor support is performed in sequence. The movement sequence starts from the first auxiliary anchor support immediately downstream of the main anchor support and moves downstream one by one.

[0015] As a preferred embodiment of the collaborative intelligent control method for equipment groups in a steeply inclined coal seam working face as described in this application, the anchoring state refers to a working mode that the main anchor support enters to resist the sliding force. The anchoring state is set as follows: when the coal mining machine is at a preset distance from the main anchor support, the column pressure of the main anchor support is reduced to the fixed pressure range, and the thrust of the balance jack is adjusted to the maximum thrust value, so that the top beam tilts upward.

[0016] As a preferred embodiment of the collaborative intelligent control method for equipment groups in a steeply inclined coal seam working face as described in this application, the monitoring method for the overall sliding cumulative displacement of the hydraulic support group is as follows: taking the first hydraulic support at the top of the working face as a fixed reference point, the sum of the relative sliding displacements of all two adjacent hydraulic supports is calculated to obtain the overall sliding cumulative displacement of the hydraulic support group. The relative sliding displacement is composed of two superimposed parts: the displacement caused by the relative sliding between the hydraulic support base and the base plate, and the additional displacement caused by the change in the projection position of the top beam or base in the inclined direction due to the change in the support tilt angle of the hydraulic support.

[0017] As a preferred embodiment of the collaborative intelligent control method for equipment groups in a steeply inclined coal seam working face described in this application, the bottom-up stepwise depressurization operation is as follows: When the cumulative downward displacement of the hydraulic support group exceeds the preset displacement threshold, normal coal mining operations are suspended. Starting from the hydraulic support at the lowest point of the working face, the cycle of actively depressurizing the main anchor support, moving the downstream anchor support forward, and repressurizing the main anchor support is executed step by step upward along the dip.

[0018] As a preferred embodiment of the collaborative intelligent control method for equipment groups in a steeply inclined coal seam working face as described in this application, the cycle of active depressurization of the main anchor support, forward movement of the downstream secondary anchor support, and repressurization of the main anchor support is as follows: taking the hydraulic support at the lowest end of the working face as the starting stage, if the current hydraulic support is the main anchor support, then the following sub-steps are executed: Active pressure relief of main anchor support: Reduces the pressure on the main anchor support column to the preset pressure reduction range and reduces the thrust of the balance jack to zero; Downstream sub-anchor support forward movement: In the sub-anchor supports downstream of the main anchor support, starting from the first sub-anchor support immediately adjacent to the main anchor support, pressurized support movement is performed sequentially, with each support moving forward by a preset small stroke; Main anchor support repressurization: restore the column pressure of the main anchor support to the fixed pressure range of the anchored state, and readjust the thrust of the balance jack to the maximum thrust value, so that the top beam can be raised again; After completing the sub-step, move upward along the dip to the previous main anchor support and repeat the sub-step until all main anchor supports have completed the sub-step once in sequence.

[0019] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: Based on real-time collected operating data of the coal mining machine and hydraulic supports, the gravitational potential energy power of the coal mining machine and the sliding force of each hydraulic support, as well as their spatial gradient along the dip direction, are calculated. Based on the gravitational potential energy power and spatial gradient, the traction speed curve of the coal mining machine along the working face is solved to control the operation of the coal mining machine. This allows the traction speed of the coal mining machine to be adaptively adjusted according to the sliding force constraint of the preceding hydraulic supports, effectively suppressing gravity acceleration runaway during descent and overload impact during ascent, reducing energy consumption and mechanical wear of the traction system. Sliding force accumulation points are identified, and main anchor supports and secondary anchor supports are selected based on preset screening rules, achieving differentiation of the support group. During the operation of the coal mining machine... After initial operation, the coordinated timing of upstream auxiliary anchor support shifting in advance, main anchor support anchoring in advance, and downstream auxiliary anchor support shifting in an orderly manner under the protection of main anchor support ensures continuous support of the roof and utilizes the strong anchoring effect of main anchor support to block the transmission path of sliding force, significantly improving the overall anti-slip stability of the support group. During the pressurized shifting process, when the cumulative displacement exceeds the preset displacement threshold, a bottom-up depressurization operation is performed to controllably transfer and dissipate the accumulated sliding potential energy downwards, effectively preventing the overall sliding of the support group from going out of control and avoiding equipment damage caused by forced jacking, thus realizing the active management and safe release of sliding potential energy. Attached Figure Description

[0020] Figure 1 A flowchart of a collaborative intelligent control method for equipment groups in a steeply inclined coal seam working face provided in this application; Figure 2 A flowchart for calculating the traction speed curve provided in this application; Figure 3 A flowchart of the bottom-up, step-by-step depressurization operation provided for this application. Detailed Implementation

[0021] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments of the present invention and the specific features in the embodiments are detailed descriptions of the technical solution of the present invention, rather than limitations thereof.

[0022] like Figure 1 As shown in the figure, this embodiment introduces a collaborative intelligent control method for equipment groups in steeply inclined coal seam working faces, including the following steps: The system collects real-time operating data of the coal mining machine and hydraulic supports, and calculates the gravitational potential energy power of the coal mining machine and the sliding force and spatial gradient along the dip direction of each hydraulic support based on the operating data. The operating data of the coal mining machine includes: the real-time position of the coal mining machine along the dip direction of the working face, the traction speed of the coal mining machine, the cutting power and the local inclination angle. The operating data of the hydraulic supports includes: the column pressure of each hydraulic support, the pressure of the balancing jack, the displacement of the pushing jack, and the inclination angle of the support.

[0023] The data acquisition method for the coal mining machine is as follows: A shaft encoder or magnetic grating displacement sensor is installed on the traction unit or traveling wheel axle of the coal mining machine. By measuring the number of rotations and direction of the traveling wheels, and combining this with the initial calibration position of the coal mining machine at the working face end, the absolute position coordinates of the coal mining machine along the dip direction are calculated in real time, i.e., the real-time position. The traction motor speed fed back by the frequency converter is read, and the traction motor speed is converted into traction speed according to the transmission ratio. The three-phase current and voltage signals are collected in real time through the frequency converter of the coal mining machine's cutting motor, and the three-phase current and voltage signals are converted into active power to obtain the cutting power. The data is then collected along the working face. Based on the face dip direction, dual-axis tilt sensors are embedded in the top or bottom plate at preset intervals to obtain the local tilt angle at the corresponding position. Based on all local tilt angles, a tilt angle distribution curve is generated through linear interpolation. The local tilt angle of the coal mining machine is obtained in real time according to the real-time position of the coal mining machine and the tilt angle distribution curve. The preset interval is less than half of the minimum characteristic wavelength of the working face tilt angle along the dip direction and matches the arrangement spacing of the hydraulic supports. In this embodiment, it is taken between one-third and one-half of the minimum characteristic wavelength. For example, if the minimum characteristic wavelength is 30 meters, the preset interval is 10 meters to 15 meters.

[0024] The data acquisition method for the hydraulic support is as follows: An intrinsically safe pressure transmitter for mining is installed in the lower chamber oil circuit of each hydraulic support column, and the oil pressure signal is continuously acquired at a fixed sampling frequency to obtain the column pressure of each hydraulic support; pressure sensors are installed in the rod-side and rodless-side oil circuits of the balancing jack to acquire the pressure on the thrust and pull sides in real time to obtain the balancing jack pressure; the balancing jack pressure includes the rodless-side pressure and the rod-side pressure; a magnetostrictive displacement sensor or a wire-type displacement sensor is installed on the cylinder or piston rod of the pushing jack to measure the jack extension length in real time to obtain the pushing jack displacement; a single-axis or dual-axis tilt sensor is fixedly installed on the base or top beam of each hydraulic support to acquire the tilt angle of the support along the working surface and vertical directions in real time to obtain the support tilt angle.

[0025] The fixed sampling frequency is determined comprehensively based on the time scale of the dynamic response of the equipment group in the steeply inclined working face, the noise characteristics of the sensors, and the real-time requirements of the control system. In this embodiment, the fixed sampling frequency should be more than twice the main frequency components of the changes in the traction speed of the coal mining machine and the sliding force of the hydraulic support, in order to satisfy the Nyquist sampling theorem; the fixed sampling frequency should be able to capture the process in which the sliding force of the hydraulic support begins to increase significantly after the coal mining machine has passed, that is, the sampling interval should be less than one-tenth to one-fifth of the propagation delay; the fixed sampling frequency also needs to be matched with the control cycle of the control system, usually set as an integer multiple of the control cycle, to ensure data synchronization.

[0026] The gravitational potential energy power is the cumulative product of the coal mining machine's traction speed, mass, gravitational acceleration, and the sine of the local inclination angle, i.e. ;in, For the coal mining machine in position x The gravitational potential energy power at that location, m For the quality of the coal mining machine, g It is the acceleration due to gravity. For the coal mining machine in position x Local tilt angle at the location The sine value, For the coal mining machine in position x The traction speed at the point; for example, if the mass of the coal mining machine is 55,000 kg, and the acceleration due to gravity is 9.8 m / s². 2 Local tilt angle If the angle is 50° and the traction speed is 0.2 m / s, then the gravitational potential energy power is approximately 55000 × 9.8 × sin50° × 0.2 ≈ 82.58 kW. The calculation method for the sliding force of each hydraulic support is as follows: For any hydraulic support, it is calculated by solving the static equilibrium equation based on the column pressure, the balancing jack pressure, the support tilt angle, and the local tilt angle of the working surface where the hydraulic support is located. The local tilt angle of the working surface where the hydraulic support is located is calculated based on the position of the hydraulic support and in combination with the tilt angle distribution curve. For example, taking the top beam and base of the hydraulic support as the objects of force, a static equilibrium equation is established along the direction of the working surface; wherein, the force acting on the hydraulic support includes the supporting force provided by the column. F col The thrust or pull force provided by the balancing jack F bal Normal support force of the base plate on the base F N With tangential friction f N And the component of the support's own weight G in the tilting direction; among which, f N forF N coefficient of friction between the base and the bottom plate The product of the two. Obtain the piston area of ​​the column. A col and the pressure on the column P col With piston area A col Multiplying them together gives the supporting force provided by the column. F col ,Right now ; Obtain the rodless cavity area of ​​the balancing jack respectively A bal1 With rod cavity area A bal2 And calculate the rodless chamber pressure. P bal1 With rodless cavity area A bal1 The product of these products is used to obtain the first product; the pressure in the rod chamber is then calculated. P bal2 With rod cavity area A bal2 The product of the first and second products is used to obtain the second product; the difference between the first and second products is calculated, i.e., the first product minus the second product, to obtain the thrust or pull force provided by the balancing jack. F bal ,Right now Since the side where the piston rod does not extend is the rodless chamber, the balance jack extends and generates thrust when high-pressure oil is introduced, while the side where the piston rod is located is the rod chamber, the jack retracts and generates tension when high-pressure oil is introduced. Therefore, if the difference between the first product and the second product is positive, it indicates that the balance jack is in a thrusting state and tends to extend outward; if the difference is negative, it indicates that the balance jack is in a tension state and tends to contract inward. Based on the inclination angle of the support and the local inclination angle of the working surface, the supporting force provided by the column and the thrust or tension provided by the balance jack are decomposed into horizontal and vertical components along the dip direction of the working surface. Since the sum of the external forces on the hydraulic support is zero along the dip direction of the working surface, the static equilibrium equation of the hydraulic support in the horizontal direction is established as follows: The static equilibrium equation in the vertical direction is: ,in, i For local tilt angle, For slip force, F b To balance the angle between the jack's axis and the horizontal direction, F cLet be the angle between the column axis and the vertical direction; in the static equilibrium equation, the sliding force exerted by the top plate on the top beam is the only unknown; solve the static equilibrium equation to obtain the sliding force exerted by the top plate on the top beam; for example, the column pressure of a certain support. P col The pressure is 30 MPa, and the piston area is... A col It is 0.1256m 2 The supporting force provided by the column =30×10 3 ×0.1256=3768kN; Area of ​​the rodless cavity of the balancing jack A bal1 It is 0.00785m 2 Rod cavity area A bal2 It is 0.00503m 2 rodless chamber pressure P bal1 The pressure in the rod chamber is 20 MPa. P bal2 If it is 5MPa, then F bal =20×10 3 ×0.00785-5×10 3 ×0.00503=131.85kN; F b It is 5°. F c It is 3°. The value is 0.35, and G is 250kN. If the angle is 50°, then substituting it into the static equilibrium equation in the vertical direction yields the following result. F N ≈3890kN, substituting all known quantities into the static equilibrium equation in the horizontal direction, we obtain... F h ≈1224.5kN.

[0027] Along the dip of the working face, the sliding forces of each hydraulic support are arranged sequentially from the head to the tail of the machine according to their support numbers, resulting in a sliding force sequence. By performing a difference operation on the sliding force sequence, the spatial gradient of the sliding force of each hydraulic support along the dip is obtained. The spatial gradient reflects the degree of drastic change of the sliding force along the dip of the working face: a positive spatial gradient indicates that the sliding force increases with the increase of the dip position of the working face, and a negative spatial gradient indicates that the sliding force decreases with the increase of the dip position of the working face. The larger the absolute value of the spatial gradient, the more uneven the distribution of the sliding force, and the higher the potential risk of instability.

[0028] For example, if the first i The sliding force of the hydraulic support isF h ( i ), then the first i The sliding force of the hydraulic support has a spatial gradient along its dip direction. F h ( i +1) Subtract F h ( i The difference between ) and L The ratio of 1; where, F h ( i +1) is the first i Downstream of the hydraulic support and with the first i The sliding force of adjacent hydraulic supports of the hydraulic support. L 1 represents the distance between the two corresponding hydraulic supports; i The support number is for the hydraulic support that is inclined downwards.

[0029] Based on the gravitational potential energy power and spatial gradient, the traction speed curve of the coal mining machine along the working face is solved, and the operation of the coal mining machine is controlled by the traction speed curve. In a steeply inclined working face, the exposed area of ​​the roof increases after the coal mining machine cuts the coal, the load of the overlying strata is redistributed, and the new load will be transmitted downward along the dip, mainly acting on the rear of the coal mining machine, that is, several supports along the dip of the working face. The greater the gravitational potential energy power released by the coal mining machine at a certain position, the more intense the energy injection obtained by the roof at that position per unit time, thus making the growth rate of the dynamic sliding force on the hydraulic supports behind it higher.

[0030] like Figure 2 As shown, the traction speed curve is solved as follows: Based on the gravitational potential energy power of the coal mining machine, the growth rate of the sliding force of each hydraulic support behind the coal mining machine is calculated. For any hydraulic support behind the coal mining machine, the growth rate of its sliding force is obtained by adding the natural term and the coal mining machine drive term. The natural term refers to the slow increase of the sliding force caused by roof creep when there is no disturbance from the coal mining machine. The coal mining machine drive term is proportional to the gravitational potential energy power when the coal mining machine passes over the hydraulic support and has a time delay.

[0031] Because the coal mining machine has passed the first i When the hydraulic support is positioned above it, the gravitational potential energy released does not immediately cause a change in the sliding force of the hydraulic support; instead, it undergoes a propagation delay. t i It only begins to have an impact later, therefore at the current moment t The rate of increase of the sliding force of the hydraulic support is determined by the coal mining machine. t-t iThe power of gravitational potential energy when the coal mining machine passes the hydraulic support is determined by the power of gravitational potential energy at each moment. Therefore, the calculation method for the coal mining machine drive term is as follows: calculate the growth coefficient of any hydraulic support, and multiply the power of gravitational potential energy of the coal mining machine when passing the corresponding hydraulic support by the growth coefficient to obtain the coal mining machine drive term for the corresponding hydraulic support. The natural term, growth coefficient, and... t i All were identified online using the recursive least squares algorithm.

[0032] Specifically, for each hydraulic support i In Q consecutive mining cycles, the gravitational potential energy power of the coal mining machine when passing the hydraulic support is collected and the timing of its occurrence is recorded. Simultaneously, the sliding force of the hydraulic support is continuously recorded. Here, Q is a positive integer. The roof lithology and contact conditions between the support and surrounding rock in a steeply inclined working face change slowly with mining progress, but the rate of change is relatively slow, usually showing significant differences only after several mining cycles. Therefore, Q can not only track this change but also suppress random disturbances in a single cycle. For example, Q is set to 5. A mining cycle refers to a complete stroke of the coal mining machine from the head to the tail and back to the head. Within any mining cycle, the gravitational potential energy power of the coal mining machine when passing the first... i The moment when the hydraulic support is erected is recorded as t 0, and search for the moment when the slip force begins to increase significantly, denoted as . t 1; Calculation t 1 and t The difference of 0, i.e. t 1 minus t 0, get t i Estimate; taken from Q consecutive coal mining cycles t i The average of the estimated values ​​is obtained t i The significant increase refers to the slope of the slip force exceeding a preset slope threshold for M consecutive sampling points; where M is a positive integer, determined based on the noise fluctuation amplitude of the slip force when there is no disturbance from the coal mining machine, for example, M is 3 to 5; the slope threshold is determined by the horizontal resistance, for example, 0.5% / second of the horizontal resistance; the central difference method is used to measure the... i The sliding force of the hydraulic support is numerically differentiated to obtain the sliding force growth rate sequence; the specific formula of the central difference method is: ,in, t j For the first j Each sampling time, t j-1 For the first j -1 sampling time, t j+1 For the first j +1 sampling time,T s The sampling interval; For the first i Hydraulic supports at sampling time t j-1 The slip force, For the first i Hydraulic supports at sampling time t j+1 The slip force; For the first i Hydraulic supports at sampling time t j The slip force growth rate; with the slip force growth rate sequence as output, and the sum of the coal mining machine driving term and the natural term after propagation delay as input, the growth coefficients in the natural term and the coal mining machine driving term are obtained through least squares fitting.

[0033] For example, the specific method for obtaining the growth coefficients in the natural term and the coal mining machine driving term through least squares fitting is as follows: Define the least squares model. ,in, for t j The rate of increase of slip force at time intervals, for t j The input item for time, i.e., the time of the coal mining machine at an earlier time. t j - t i After the first i Gravitational potential energy power when erecting hydraulic supports , The growth coefficient, For natural terms; set the observation vector as and initialize the parameter vector as covariance matrix Forgetting factor ,in T It is the transpose symbol. I It is the identity matrix; for each sampling time... t j Calculate the gain vector , and prediction error The sampling time is obtained. t j parameter vector And update the covariance matrix. ;in, Sampling time t j The covariance matrix, Sampling time t j-1The covariance matrix, Sampling time t j-1 The estimated value of the parameter vector; Sampling time t j-1 The growth rate, Sampling time t j-1 The natural term; the final growth coefficient is the first term of the parameter vector, and the natural term is the second term of the parameter vector.

[0034] From the current position of the coal mining machine x 0 Starting from the direction of the coal mining machine's movement, divide the distance L2 meters ahead into N equally spaced discrete points. x k ;in, k =1,2,...,N; L2 is the preset prediction window length, which is determined based on the total length of the working face and the response time of the control system; N is the preset number of discrete points, which is determined by the resolution requirements of the traction speed curve and the sampling interval of the coal mining machine's operating data. For example, if the total length of the working face is in the range of hundreds of meters, the rated speed of the coal mining machine is in the range of several meters to tens of meters per minute, and the response time of the control system is in the range of seconds, then the prediction window length is set to the distance traveled by the coal mining machine in several seconds to tens of seconds, for example, five percent to ten percent of the total length of the working face; when the prediction window length is tens of meters, the number of discrete points is taken to a value that makes the distance between adjacent points in the range of decimeters to meters, for example, making the ratio of L2 to N between one point per meter and several points per meter, and ensuring that the distance between adjacent points matches the sampling distance of the dual-axis tilt sensor.

[0035] For any discrete point x k The following steps are taken: First, determine the set of hydraulic supports within the effective operating distance behind the support. Second, determine the growth rate threshold for each hydraulic support in the set. Third, based on the corresponding sliding force growth rate and the growth rate threshold, calculate the allowable gravitational potential energy power threshold for each hydraulic support in the set. Fourth, since there is an upper limit to the sliding force growth rate that a hydraulic support can safely withstand, i.e., the growth rate threshold, the sliding force growth rate of any hydraulic support in the set should be less than or equal to the corresponding growth rate threshold. The allowable gravitational potential energy power threshold is: the difference between the growth rate threshold corresponding to the hydraulic support and the corresponding natural term, i.e., the ratio of the growth rate threshold corresponding to the hydraulic support minus the corresponding natural term to the growth coefficient.

[0036] In this embodiment, the effective action distance refers to the maximum spatial range within which the gravitational potential energy released by the coal mining machine at a certain position can significantly affect the hydraulic support behind it. The effective action distance is determined based on the roof lithology or the arrangement spacing between hydraulic supports. After the coal mining machine cuts coal, the stress increment generated in the exposed area of ​​the roof is not transmitted indefinitely, but gradually decreases with the increase of distance from the coal mining machine. When the stress increment decreases to a negligible level, for example, below 5% of the rated sliding force of the hydraulic support, the distance between it and the coal mining machine is the effective action distance. "Behind" refers to the downward slope along the working face. The growth rate threshold is determined based on the rated horizontal bearing capacity of the corresponding hydraulic support. For example, when the hydraulic support leaves the factory, its structural design, such as the top beam, base, column, balance jack, connecting pin, etc., has a rated horizontal working resistance. This horizontal working resistance corresponds to the maximum static sliding force that the hydraulic support can safely withstand for a long time. The growth rate threshold is usually taken as 70% to 85% of the rated horizontal working resistance and divided by the allowable response time of the hydraulic support to ensure that dynamic impact does not cause structural plastic deformation or fatigue damage.

[0037] Extracting discrete points x k The minimum value of the allowable gravitational potential energy power threshold of all hydraulic supports in the corresponding set of hydraulic supports is used to obtain discrete points. x k Maximum permissible gravitational potential power at that location Based on the maximum permissible gravitational potential power and discrete points x k The local tilt angle at the point is used to calculate the discrete point. x k The maximum speed at the location; specifically, the maximum speed is calculated by calculating the mass of the coal mining machine, the acceleration due to gravity, and the discrete point. x k The cumulative product of the local tilt angles at the discrete points, and the discrete points x k The ratio of the maximum permissible gravitational potential power at a given point to the cumulative product is used as the discrete point. x k Maximum speed at ,Right now .

[0038] For example, It is 250kW. m It is 55,000 kg. If it is 50°, then The value is approximately 250000 / (55000×9.8×sin50°)≈0.607m / s.

[0039] Discrete points within the prediction window length x kAt this point, with the maximum speed as a constraint, and with the optimization objectives of minimizing the deviation between the traction speed and the rated speed of the coal mining machine and minimizing the fluctuation amplitude of gravitational potential power between adjacent discrete points, an objective function is constructed. Specifically, calculate the traction speed of the coal mining machine. With rated speed The difference, i.e., the traction speed minus the rated speed, is used to obtain the first difference; the gravitational potential power at each discrete point is calculated, and the difference in gravitational potential power between adjacent discrete points is also calculated, i.e., the difference in gravitational potential power between discrete points. x k gravitational potential power at the location Subtract discrete points x k-1 gravitational potential power at the location The second difference is obtained; the gravitational potential power at each discrete point is the cumulative product of the traction speed of the coal mining machine at the corresponding position, the mass of the coal mining machine, the gravitational acceleration, and the sine of the local inclination angle at the corresponding discrete point; the square of the ratio of the second difference to the interval of adjacent discrete points and the square of the first difference are weighted and summed to obtain the objective function, denoted as . ;in, The weighting coefficient is the ratio of the distance between adjacent discrete points, i.e., L2 to N, and the square of the ratio of the second difference to the distance between adjacent discrete points. The weighting coefficient of the square of the first difference To balance speed tracking accuracy and power stability, in this embodiment, Set to 0.6, Set it to 0.4.

[0040] The traction speed curve must simultaneously satisfy the following constraints: the traction speed at each discrete point is less than or equal to the maximum speed corresponding to that discrete point; the rate of change of speed between adjacent discrete points is less than or equal to the maximum allowable acceleration of the coal mining machine traction system; the gravitational potential energy power at each discrete point is less than or equal to the maximum allowable gravitational potential energy power corresponding to that discrete point; a numerical optimization method is used to solve for the traction speed sequence corresponding to minimizing the objective function under the premise of satisfying the above constraints; the traction speed sequence is smoothed to obtain the traction speed curve. Optionally, the numerical optimization method can be any one of dynamic programming, sequential quadratic programming, or gradient projection method, which will not be elaborated here.

[0041] Based on the sliding force of each hydraulic support and its spatial gradient along the dip direction, the sliding force accumulation point is identified, and the main anchor support and the secondary anchor support are selected in combination with the preset screening rules. The sliding force accumulation point refers to the point where the spatial gradient of the sliding force along the dip direction of the working surface is greater than 0 and the spatial gradient value exceeds the preset gradient threshold. Specifically, when the spatial gradient of the sliding force at any hydraulic support is greater than 0 and its absolute value is greater than the preset gradient threshold, it indicates that there is a significant trend of increasing sliding force in the downstream direction of the hydraulic support, and the location of the hydraulic support is the sliding force accumulation point. The sliding force accumulation point indicates that the point and its downstream area face a high risk of instability, and it is necessary to set up a main anchor support downstream of the point to block the continuous transmission of sliding force.

[0042] Optionally, the preset gradient threshold is determined based on the normal fluctuation range of the hydraulic support sliding force distribution along the dip and engineering safety requirements. Specifically, the gradient threshold should be 3 to 5 times greater than the noise fluctuation amplitude of the sliding force spatial gradient when there is no coal mining machine disturbance, to avoid false triggering caused by measurement noise or minor local undulations in the roof. The gradient threshold should also be less than the gradient value at the initial stage of sliding force accumulation, to ensure that accumulation points are identified before the sliding force reaches a dangerous level. For example, spatial gradient data without significant sliding force accumulation in multiple coal mining cycles are obtained, their standard deviation is calculated, and the gradient threshold is set to 3 to 5 times the standard deviation. The gradient threshold can be adjusted online according to the actual operating effect of the working face: if too many sliding force accumulation points are identified, resulting in excessively dense main anchor supports, the gradient threshold is increased; if missed detection leads to support instability events, the gradient threshold is decreased.

[0043] The selection rules for the main anchor support and the secondary anchor support are as follows: For each identified slip force accumulation point, the first hydraulic support in its downstream direction is selected as the candidate main anchor support; if the distance between any two adjacent slip force accumulation points is less than a preset spacing threshold, then the candidate main anchor support of the slip force accumulation point further downstream of the corresponding two adjacent slip force accumulation points is selected as the main anchor support; if the distance between all adjacent slip force accumulation points is greater than or equal to the spacing threshold, then the candidate main anchor support of each slip force accumulation point is selected as the corresponding main anchor support; all hydraulic supports other than the main anchor support are set as secondary anchor supports; the main anchor support is updated once every coal mining cycle to adapt to changes in the slip force field.

[0044] The spacing threshold is determined based on the arrangement spacing of the hydraulic supports on the working face and the spatial distribution characteristics of the sliding force accumulation points. Specifically, the spacing threshold should be 2 to 4 times greater than the center distance of the hydraulic supports to ensure that if two sliding force accumulation points are too close, they are merged to avoid the main anchor supports being set too densely. The spacing threshold should also consider the influence range of sliding force accumulation, that is, the effective anchoring effect of one main anchor support can usually cover the range of several downstream hydraulic supports. Therefore, if the distance between two sliding force accumulation points is less than this coverage range, the main anchor support is only set at the farthest downstream sliding force accumulation point. Optionally, the spacing threshold can be calibrated through field tests: the initial spacing threshold is set to 3 times the center distance, and the change in the sliding force field is observed after the main anchor supports are set. If new sliding force accumulation points still appear between the two main anchor supports, the spacing threshold is appropriately reduced. If the distance between the main anchor supports is too close, causing abnormal force on the supports, the spacing threshold is appropriately increased.

[0045] After the coal mining machine starts operating, the downstream auxiliary anchor supports upstream of the main anchor support are controlled to perform pressurized frame shifting in sequence. Pressurized frame shifting refers to the hydraulic support maintaining the column pressure within the corresponding pressurized range during the frame shifting process, while ensuring that the top beam remains in contact with the roof to maintain basic support for the roof and reduce the resistance of frame shifting. When the coal mining machine is at a preset distance from the main anchor support, the main anchor support is controlled to enter the anchoring state, and after the main anchor support enters the anchoring state, the downstream auxiliary anchor supports are controlled to perform pressurized frame shifting in sequence. The anchoring state refers to a special working mode that the main anchor support enters to resist sliding force. In this working mode, the column pressure of the main anchor support is actively reduced to a preset fixed pressure range to reduce the normal pressure on the roof, while the thrust of the balance jack is adjusted to the preset maximum thrust value so that the top beam tilts upward, thereby forming a wedge effect at the front end of the top beam to resist sliding force. Specifically, for the secondary anchor support upstream of the main anchor support, when the coal mining machine passes over it, the secondary anchor support immediately performs a shifting action, and maintains the column pressure within the corresponding pressurized range during the shifting process; the pressurized range is a preset proportion greater than or equal to the rated pressure of the corresponding hydraulic support column; when the coal mining machine is at a preset distance from the main anchor support, the column pressure of the main anchor support is reduced to the fixed pressure range, and the thrust of the balancing jack is adjusted to the maximum thrust value, so that the top beam tilts upward; after the coal mining machine passes the main anchor support and the main anchor support has entered the anchored state, the pressurized shifting operation of the secondary anchor supports downstream of the main anchor support is performed in sequence, and the shifting sequence starts from the first secondary anchor support immediately downstream of the main anchor support and proceeds downstream one by one; the pressurized shifting not only avoids the sudden increase in sliding force caused by the instantaneous suspension of the roof during the shifting process, but also maintains the stability of the hydraulic support by utilizing the continuous support of the roof.

[0046] In this embodiment, the preset ratio is set according to the requirements of continuous support for the roof and the need to suppress sliding force: to ensure that the roof does not momentarily become suspended or excessively subside during the relocation process, the column pressure must provide sufficient support to resist the self-weight of the roof rock strata and the transmitted load. If the lower limit of the pressure range is too low, the roof will lose contact with the roof beam, inducing roof delamination or local collapse; if the lower limit of the pressure range is too high, the relocation resistance will increase, and may even cause difficulty in pushing the support or damage to the base plate. Under steep inclination conditions, the sliding force of the roof on the support is closely related to the positive pressure provided by the column. Appropriately maintaining the column pressure can maintain the frictional anchoring effect between the base and the base plate during the relocation process, preventing the hydraulic support from sliding down at the moment of relocation. For example, the lower limit of the pressure range is taken as 30% of the rated pressure of the corresponding hydraulic support column, which can ensure effective support for the roof and control the relocation resistance within a reasonable range.

[0047] Optionally, the preset distance is determined based on the traction speed of the coal mining machine, the response time of the hydraulic support anchoring action, and the delay characteristics of the roof load transmission. The faster the traction speed of the coal mining machine, the shorter the time required to approach the main anchor support, and the larger the preset distance, so as to ensure that there is sufficient time to complete the anchoring action before the coal mining machine arrives. The response time refers to the total time required for the main anchor support to complete the anchoring action, and the preset distance should be greater than the distance traveled by the coal mining machine within that response time. After the coal mining machine cuts the coal, there is an inherent propagation delay in the transmission of the roof stress increment to the lower hydraulic support. In order to ensure that the anchoring action is completed before the slip force increases, the preset distance should also take into account the travel distance of the coal mining machine corresponding to this propagation delay.

[0048] Optionally, the pressure range refers to the target pressure range to which the column pressure needs to be actively reduced when the main anchor support is in the anchored state. If the column pressure is too high, it will press the top beam and the top plate together, making it impossible for the balance jack to overcome friction and lift the top beam. If the column pressure is too low, the top beam will lose support, and the top plate may sink or the support may become unstable. The pressure range must ensure that under the action of the maximum thrust of the balance jack, the top beam can rotate upstream around the hinge point, while the top plate does not sink significantly. For example, the pressure range is 60% to 80% of the corresponding rated pressure of the column, determined by on-site calibration: before the coal mining machine arrives, the column pressure is gradually reduced and the attitude of the top beam is observed. When the balance jack can reliably lift the top beam by 1° to 2° with the maximum thrust, the column pressure at this time is recorded as the upper limit of the pressure range, and then the pressure is reduced by 5% to 10% of the upper limit as the lower limit of the pressure range to reserve adjustment margin. The maximum thrust value refers to the maximum thrust that the balancing jack can output, that is, the thrust generated when the rodless chamber of the jack reaches the rated pressure of the hydraulic system.

[0049] During the pressurized relocation process, the cumulative downward displacement of the entire hydraulic support group is monitored in real time. When the cumulative downward displacement exceeds a preset displacement threshold, a bottom-up depressurization operation is performed. The monitoring method for the cumulative downward displacement of the entire hydraulic support group is as follows: taking the first hydraulic support at the top of the working surface as a fixed reference point, for two adjacent hydraulic supports... i and i -1, calculate the first i The hydraulic support frame relative to the first i The relative sliding displacement of one hydraulic support is calculated, and the relative sliding displacements of all adjacent hydraulic supports are summed to obtain the total cumulative sliding displacement of the hydraulic support group. The relative sliding displacement consists of two parts: the displacement caused by the relative sliding between the hydraulic support base and the base plate, and the additional displacement caused by the change in the projection position of the top beam or base in the inclined direction due to the change in the support inclination angle of the hydraulic support.

[0050] Specifically, the pushing jack is used to realize the moving action of the hydraulic support, and the change in its extension length reflects the change in position of the hydraulic support relative to the scraper conveyor; the displacement between adjacent hydraulic supports caused by the relative sliding between the hydraulic support base and the base plate is calculated as follows: obtain the displacement of the first hydraulic support, the second hydraulic support, the third hydraulic support, the fourth hydraulic support, the fifth hydraulic support, the sixth hydraulic support, the seventh hydraulic support, the eighth hydraulic support, the ninth hydraulic support, the tenth ... i Hydraulic support and the first i -1 The extension length of the pushing jacks of the hydraulic supports at their respective initial positions, and the lengths of the first hydraulic support at each position are obtained. i Hydraulic support and the first i -1. Calculate the extension length of the pushing jack of the hydraulic support at the current moment; i The extension length of the pushing jack of the hydraulic support in its initial position, and the first i The difference in the extension length of the hydraulic support's pushing jack at the current moment, i.e., the value of the first... i The extension length of the hydraulic support jack in its initial position minus the first... i The extension length of the hydraulic support jack at the current moment is used to obtain the third difference, and the second difference is calculated. i -1. The extension length of the pushing jack of the hydraulic support in its initial position, compared with the first... i -1 is the difference in the extension length of the pushing jack of the hydraulic support at the current moment, i.e., the value of the first... i -1. The extension length of the pushing jack of the hydraulic support in its initial position minus the length of the [missing information]. i-1. Calculate the extension length of the hydraulic support's jack at the current moment to obtain the fourth difference; calculate the difference between the third and fourth differences, i.e., subtract the fourth difference from the third difference, to obtain the displacement caused by the relative sliding between the hydraulic support base and the base plate. When the inclination angle of the support base changes, the projected position of the support in the inclined direction will change. The calculation method for the additional displacement caused by the change in the projected position of the top beam or base in the inclined direction due to the change in the hydraulic support's inclination angle is as follows: Calculate the... i The sine of the base tilt angle of the hydraulic support is related to the first... i The difference in the sine of the base tilt angle of the -1 hydraulic support, i.e., the th i The sine of the base tilt angle of the hydraulic support minus the first... i -1. Obtain the sine value of the base inclination angle of the hydraulic support and get the fifth difference value; obtain the base length of the hydraulic support and calculate the product of the base length and the fifth difference value to obtain the additional displacement caused by the change in the projection position of the top beam or base in the inclined direction due to the change in the support inclination angle of the hydraulic support.

[0051] For example, suppose the first i The initial extension length of the hydraulic support jack is The current extension length is The current base tilt angle is The base length is B, and the first i- The initial extension length of the jack of a hydraulic support is The current extension length is The current base tilt angle is Then the first i The hydraulic support frame relative to the first i The relative downward displacement of the -1 hydraulic support is Taking the first support frame at the top of the working face as a fixed reference point, set... S If 1(t) = 0, then the th n Absolute downward displacement of the support frame The absolute downward displacement of the last support at the lowest point of the working face is taken as the cumulative downward displacement of the entire hydraulic support group. Let... B =4m, =49° =48°, then ≈46.4mm, let =10mm, =3mm, then =7 + 46.4 = 53.4 mm; if If the sum of the relative downward displacements of the last support is 200mm, then the total cumulative downward displacement of the hydraulic support group is 200mm.

[0052] The displacement threshold is determined comprehensively based on the geological conditions of the working face, the structural parameters of the hydraulic support, and the requirements of the mining process. Specifically, the displacement threshold should be less than the smaller of the maximum compensation stroke of the hydraulic support's pushing jack and the maximum allowable slippage of the base anti-slip structure, so as to ensure that the hydraulic support can still be effectively reset after the pressure relief operation is triggered. The displacement threshold needs to take into account the periodic collapse step distance of the roof and the coupling deformation characteristics of the support and the surrounding rock, so as to avoid affecting normal production due to frequent triggering of pressure relief operations. For example, the displacement threshold is taken as one to three percent of the length of the hydraulic support base, or five to ten percent of the rated stroke of the pushing jack.

[0053] like Figure 3 As shown, the bottom-up, step-by-step depressurization operation refers to the following: when the cumulative downward displacement of the entire hydraulic support group exceeds a preset displacement threshold, normal coal mining operations are suspended. Starting from the hydraulic support at the bottom of the working face, the cycle of "active depressurization of the main anchor support, forward movement of the downstream sub-anchor support, and repressurization of the main anchor support" is executed step-by-step upwards along the dip direction, transferring the accumulated sliding potential energy downwards in the form of waves and ultimately dissipating it on the floor. Specifically, taking the hydraulic support at the bottom of the working face as the starting level, if the current hydraulic support is the main anchor support, it is marked as the depressurization target, and the following sub-steps are executed: Active pressure relief of main anchor support: Actively reduce the column pressure of the main anchor support to the preset pressure reduction range, and at the same time reduce the thrust of the balance jack to zero, so that the top beam and the top plate are no longer in close contact, and release the sliding force borne by the hydraulic support. Downstream from the anchor support forward movement: Among the downstream anchor supports of the main anchor support, starting from the first anchor support adjacent to the main anchor support, the pressurized support movement is performed sequentially, with each support moving forward by a preset small stroke, so that the entire hydraulic support group moves downstream as a whole. Main anchor support repressurization: The column pressure of the main anchor support is restored to the fixed pressure range of the anchored state, and the thrust of the balance jack is readjusted to the maximum thrust value, so that the top beam is raised again and the anchoring capacity is restored.

[0054] After completing the above sub-steps, move upwards along the dip to the previous main anchor support, and repeat the above sub-steps until all main anchor supports have completed the sub-steps of main anchor support active depressurization, downstream anchor support forward movement, and main anchor support repressurization in sequence.

[0055] Optionally, the purpose of reducing the pressure on the main anchor support is to release the sliding force borne by the main anchor support, so that the main anchor support no longer becomes a rigid obstacle to the transmission of upstream sliding force; therefore, the pressure of the column after pressure reduction should be low enough to significantly reduce the friction between the top beam and the top plate, allowing the top plate to slip slightly along the dip; in this embodiment, the upper limit of the pressure reduction range is 50% to 70% of the lower limit of the fixed pressure range, and the lower limit of the pressure reduction range is 20% to 30% of the rated pressure of the column, but not lower than the closing pressure of the column safety valve. For example, if the rated pressure of the column is 40MPa, and the lower limit of the fixed pressure range is 40×0.6=24MPa, then the upper limit of the pressure reduction range is 0.6×24=14.4MPa, and the lower limit of the pressure reduction range is 40×0.25=10MPa; if the closing pressure of the column safety valve is 11MPa, then the lower limit of the pressure reduction range is set to 11MPa; the micro-stroke refers to the distance that each anchor support moves forward in a single step during the downstream sequential movement of the anchor support; the micro-stroke determines the total displacement of the hydraulic support group moving downstream in each step-by-step depressurization operation; if the micro-stroke is too large, it will cause the sliding potential energy to be released too suddenly, causing the hydraulic support to slide uncontrollably or the top plate to collapse suddenly; if the micro-stroke is too small, the depressurization efficiency is low, and multiple cycles are required to eliminate the accumulated sliding displacement; in this embodiment, the micro-stroke is taken as 2% to 10% of the center distance of the hydraulic support, for example, 50 to 200 mm.

[0056] After completing the bottom-up step-by-step depressurization operation, the cumulative downward displacement of the entire hydraulic support group is remeasured. If the cumulative downward displacement still exceeds the displacement threshold, the bottom-up step-by-step depressurization operation is repeated; if the cumulative downward displacement is lower than the displacement threshold, the normal coal mining mode is restored.

[0057] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0058] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of protection of this application, and these forms are all within the protection scope of this application.

Claims

1. A collaborative intelligent control method for equipment groups in a steeply inclined coal seam working face, characterized in that, Includes the following steps: Real-time acquisition of working condition data of coal mining machine and hydraulic support, and calculation of the gravitational potential energy power of coal mining machine and the sliding force and spatial gradient along the dip of each hydraulic support based on the working condition data; Based on the gravitational potential power and spatial gradient, the traction speed curve of the coal mining machine along the working face is solved, and the operation of the coal mining machine is controlled by the traction speed curve. Based on the sliding force of each hydraulic support and its spatial gradient along the dip, the sliding force accumulation point is identified, and the main anchor support and the secondary anchor support are selected in combination with the preset screening rules. After the coal mining machine starts running, the upstream secondary anchor supports of the main anchor support are controlled to perform pressurized frame shifting in sequence; when the coal mining machine is at a preset distance from the main anchor support, the main anchor support is controlled to enter the anchoring state, and after the main anchor support enters the anchoring state, the downstream secondary anchor supports of the main anchor support are controlled to perform pressurized frame shifting in sequence. During the pressurized relocation process, the cumulative downward displacement of the hydraulic support group as a whole is monitored in real time. When the cumulative downward displacement exceeds the preset displacement threshold, a step-by-step depressurization operation is performed from bottom to top. The traction speed curve is solved as follows: Based on the gravitational potential energy power of the coal mining machine, the sliding force growth rate of each hydraulic support behind the coal mining machine is calculated. Starting from the current position of the coal mining machine, along the direction of the coal mining machine's travel, the preset prediction window length in front is divided into N equally spaced discrete points; N is the number of discrete points. For any discrete point, determine the set of hydraulic supports within the effective working distance behind it, and calculate the maximum speed of each hydraulic support in the set of hydraulic supports at each discrete point based on the slip force growth rate. With the maximum speed as a constraint, and with the optimization objectives of minimizing the deviation between the traction speed and the rated speed of the coal mining machine and minimizing the fluctuation amplitude of gravitational potential power between adjacent discrete points, an objective function is constructed. The objective function was solved using numerical optimization methods to obtain the traction speed curve within the prediction window. When the spatial gradient of the sliding force at any hydraulic support is greater than 0 and the absolute value is greater than the preset gradient threshold, the location of the corresponding hydraulic support is set as the sliding force accumulation point. The steps of selecting the main anchor support and the secondary anchor support based on preset screening rules specifically include: For each identified point of slip force accumulation, the first hydraulic support in its downstream direction is selected as the candidate main anchor support. If the distance between any two adjacent sliding force accumulation points is less than the preset spacing threshold, then the candidate main anchor support of the sliding force accumulation point further downstream of the corresponding two adjacent sliding force accumulation points will be taken as the main anchor support. If the distance between all adjacent slip force accumulation points is greater than or equal to the spacing threshold, then the candidate main anchor support for each slip force accumulation point is taken as the corresponding main anchor support. All hydraulic supports except the main anchor support are set as secondary anchor supports; the main anchor support is updated once every coal mining cycle.

2. The method for collaborative intelligent control of equipment groups in a steeply inclined coal seam working face as described in claim 1, characterized in that, The calculation methods for the sliding force of each hydraulic support and its spatial gradient along the dip direction are as follows: Establish the static equilibrium equation for any hydraulic support, and based on the column pressure, balancing jack pressure, support tilt angle and corresponding local tilt angle of the corresponding hydraulic support, solve the static equilibrium equation to obtain the sliding force of the corresponding hydraulic support. Along the dip of the working face, the sliding forces of each hydraulic support are arranged sequentially from the head to the tail of the machine according to their support numbers to obtain the sliding force sequence; By performing a differential operation on the sliding force sequence, the spatial gradient of the sliding force of each hydraulic support along the dip direction is obtained.

3. The method for collaborative intelligent control of equipment groups in a steeply inclined coal seam working face as described in claim 1, characterized in that, The growth rate of the slip force is obtained by adding the natural term to the coal mining machine drive term; For each hydraulic support, the gravitational potential energy power of the coal mining machine as it passes the corresponding hydraulic support is collected in Q consecutive coal mining cycles, and the sliding force of the corresponding hydraulic support is continuously recorded; Q is a positive integer. The sliding force of the hydraulic support is numerically differentiated to obtain the sliding force growth rate sequence; the gravitational potential energy power of the coal mining machine when passing the corresponding hydraulic support is multiplied by the growth coefficient to obtain the coal mining machine drive term of the corresponding hydraulic support. The slip force growth rate sequence is used as the output, and the sum of the coal mining machine drive term and the natural term after propagation delay is used as the input. The natural term and growth coefficient are calculated by fitting.

4. The method for collaborative intelligent control of equipment groups in a steeply inclined coal seam working face as described in claim 3, characterized in that, The calculation steps for the maximum speed are as follows: For any discrete point, determine the growth rate threshold of each hydraulic support in the set of hydraulic supports corresponding to the discrete point, and calculate the difference between the growth rate threshold and the corresponding natural term; Calculate the ratio of the difference to the corresponding growth coefficient to obtain the allowable gravitational potential energy power threshold of the corresponding hydraulic support; Extract the minimum value of the allowable gravitational potential energy power threshold of all hydraulic supports in the set of hydraulic supports corresponding to any discrete point, and obtain the maximum allowable gravitational potential energy power of the corresponding discrete point. Calculate the cumulative product of the coal mining machine's mass, gravitational acceleration, and local inclination angle at any discrete point, and calculate the ratio of the maximum allowable gravitational potential power at the corresponding discrete point to the cumulative product to obtain the maximum velocity at the corresponding discrete point.

5. The method for collaborative intelligent control of equipment groups in a steeply inclined coal seam working face as described in claim 1, characterized in that, The objective function is constructed as follows: Calculate the difference between the traction speed and the rated speed of the coal mining machine to obtain the first difference; calculate the gravitational potential power at each discrete point, and calculate the difference between the gravitational potential power between adjacent discrete points to obtain the second difference; Calculate the square of the ratio of the second difference to the interval of the adjacent discrete points to obtain the first squared value, and then calculate the square of the first difference to obtain the second squared value; The objective function is obtained by weighted summation of the first squared value and the second squared value.

6. The method for collaborative intelligent control of equipment groups in a steeply inclined coal seam working face as described in claim 1, characterized in that, The specific method of the pressurized frame transfer is as follows: For the secondary anchor support upstream of the main anchor support, when the coal mining machine passes over it, the corresponding secondary anchor support immediately performs a support shifting action, and during the shifting process, the column pressure is maintained within the corresponding pressure range; The pressure range is a preset proportion that is greater than or equal to the rated pressure of the corresponding hydraulic support column. After the coal mining machine passes the main anchor support and the main anchor support has entered the anchoring state, the movement of the downstream auxiliary anchor supports downstream of the main anchor support is performed in sequence. The movement sequence starts from the first auxiliary anchor support immediately downstream of the main anchor support and moves downstream one by one.

7. The method for collaborative intelligent control of equipment groups in a steeply inclined coal seam working face as described in claim 6, characterized in that, The anchoring state refers to a working mode that the main anchor support enters to resist slippage force; The anchoring state is set as follows: when the coal mining machine is at a preset distance from the main anchor support, the column pressure of the main anchor support is reduced to the fixed pressure range, and the thrust of the balance jack is adjusted to the maximum thrust value, so that the top beam tilts upward.

8. The method for collaborative intelligent control of equipment groups in a steeply inclined coal seam working face as described in claim 1, characterized in that, The method for monitoring the cumulative downward displacement of the hydraulic support group as a whole is as follows: taking the first hydraulic support at the top of the working face as a fixed reference point, calculate the sum of the relative downward displacements of all two adjacent hydraulic supports to obtain the cumulative downward displacement of the hydraulic support group as a whole. The relative sliding displacement is composed of two superimposed parts: the displacement caused by the relative sliding between the hydraulic support base and the base plate, and the additional displacement caused by the change in the projection position of the top beam or base in the inclined direction due to the change in the support tilt angle of the hydraulic support.

9. The method for collaborative intelligent control of equipment groups in a steeply inclined coal seam working face as described in claim 1, characterized in that, The bottom-up, step-by-step depressurization operation is as follows: When the cumulative downward displacement of the hydraulic support group exceeds the preset displacement threshold, normal coal mining operations are suspended. Starting from the hydraulic support at the lowest point of the working face, the cycle of actively depressurizing the main anchor support, moving the downstream anchor support forward, and repressurizing the main anchor support is executed step by step upward along the dip.

10. The method for collaborative intelligent control of equipment groups in a steeply inclined coal seam working face as described in claim 9, characterized in that, The cycle of active depressurization of the main anchor support, downstream movement from the anchor support, and repressurization of the main anchor support is as follows: taking the hydraulic support at the lowest end of the working face as the starting stage, if the current hydraulic support is the main anchor support, then the following sub-steps are executed: Active pressure relief of main anchor support: Reduces the pressure on the main anchor support column to the preset pressure reduction range and reduces the thrust of the balance jack to zero; Downstream sub-anchor support forward movement: In the sub-anchor supports downstream of the main anchor support, starting from the first sub-anchor support immediately adjacent to the main anchor support, pressurized support movement is performed sequentially, with each support moving forward by a preset small stroke; Main anchor support repressurization: restore the column pressure of the main anchor support to the fixed pressure range of the anchored state, and readjust the thrust of the balance jack to the maximum thrust value, so that the top beam can be raised again; After completing the sub-step, move upward along the dip to the previous main anchor support and repeat the sub-step until all main anchor supports have completed the sub-step once in sequence.

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