A method and system for periodic pressure analysis of coal mine longwall faces

Abstract

This invention provides a method and system for analyzing periodic pressure inflows in coal mine longwall faces, relating to the field of intelligent coal mine prediction. It includes: collecting working resistance data of the face supports; extracting the end-cycle resistance using a minimum threshold method combined with a resistance change gradient method; using the sum of the time-weighted working resistance and the mean square error of the end-cycle resistance of the supports as the pressure inflow criterion; considering pressure inflow as occurring when both the working resistance and the end-cycle resistance curves simultaneously reach their respective pressure inflow criters, and recording the pressure inflow time and step distance; establishing a pressure inflow step distance prediction model to predict the pressure inflow step distance and duration for all supports; determining that adjacent supports with a pressure inflow prediction time difference less than a set threshold are considered to be experiencing the same pressure inflow, and simultaneously calculating the current pressure inflow prediction area and pressure inflow step distance; and analyzing the minimum periodic pressure inflow step distance, maximum pressure inflow duration, and maximum pressure inflow influence range based on historical pressure inflow prediction results. This invention can accurately calculate the periodic pressure inflow pattern of the longwall face.

Description

Technical Field

[0001] This invention relates to the field of intelligent prediction in coal mines, and in particular to a method and system for analyzing the periodic pressure of coal mine longwall faces. Background Technology

[0002] As coal mining depth and intensity gradually increase, mining conditions become more complex, and phenomena such as coal face spalling and support "crushing" occur more frequently, directly affecting the safe and efficient production of mines. Therefore, studying the characteristics of coal face stress manifestations and effectively predicting their patterns is of great significance for guiding safe production in coal mines.

[0003] Currently, most longwall mining faces have achieved massive and efficient monitoring of support column resistance data, but there are no effective means for in-depth mining and analysis. Traditional analysis methods still rely on manually exporting historical data, selecting a portion of supports for simple data analysis, and manually recording the resistance at the end of the cycle. This cannot guarantee data reliability, and the manual workload is enormous, resulting in poor data analysis results and failing to fully analyze and utilize the massive monitoring data.

[0004] As another approach to mine pressure analysis, mechanical research has yielded various theories over many years, including the pressure arch hypothesis, cantilever beams (slabs), and masonry beams. Mechanical research often uses the stress on rocks as the basis for analysis. However, field observations present safety risks, and the varying mechanical properties of overlying strata mean that the resulting mine pressure patterns are only applicable to nearby working faces or mining areas, with limited effectiveness in extending to other coal mine working faces. Summary of the Invention

[0005] In view of the above problems, the present invention proposes a method and system for periodic pressure analysis of coal mine longwall faces.

[0006] This invention provides a method for periodic pressure analysis of coal mine longwall faces, the method comprising:

[0007] The working resistance of the support structure at the data acquisition working face;

[0008] The end-cycle resistance of the support is extracted based on the working resistance of the support.

[0009] The pressure criterion is determined based on the working resistance of the support and the end-cycle resistance of the support.

[0010] Historical data is obtained based on the pressure criterion, and the historical data includes: the occurrence of periodic pressure, the pressure time, and the pressure step distance;

[0011] An inrush prediction model is established based on the historical data. The inrush prediction model is used to predict the inrush step distance and inrush duration of all stents.

[0012] The predicted area and step size for the next pressure event are obtained by using the pressure prediction model.

[0013] Optionally, the working resistance of the support at the working face is collected, including:

[0014] The pressure values ​​of individual struts of the support were collected;

[0015] The working resistance of the support is calculated based on the pressure value of the individual support column.

[0016] The formula for calculating the working resistance of the support is as follows:

[0017]

[0018] In the above formula, P represents the working resistance of the support, p1 represents the pressure value of the left support, p2 represents the pressure value of the right support, and d represents the inner diameter of the single support.

[0019] Optionally, the end-cycle resistance of the stent is extracted based on the working resistance of the stent, including:

[0020] The minimum threshold method and the resistance change gradient method are used to process the working resistance of the stent to extract the end-cycle resistance of the stent.

[0021] Optionally, the minimum threshold method is used to process the working resistance of the stent, combined with the resistance change gradient method, to extract the end-cycle resistance of the stent, including:

[0022] Set the minimum working resistance threshold after the support unloading and lowering stage;

[0023] Set the difference in working resistance of the support before and after the support unloading and lowering stage;

[0024] Select the previous working resistance that is less than the minimum working resistance threshold from all the working resistances of the stents, and the monitoring time corresponding to the previous working resistance is the previous monitoring time;

[0025] The average descent time of the support was calculated based on the sampling interval and the actual descent time of the support at the working face.

[0026] Calculate the subsequent working resistance corresponding to the subsequent monitoring time, wherein the subsequent monitoring time is the difference between the previous monitoring time and the average descent time of the support;

[0027] If the difference between the subsequent working resistance and the preceding working resistance is greater than the difference in the working resistance of the support, then the maximum supporting force provided by the support to the top plate before the support is unloaded and lowered is obtained, and this maximum supporting force is the end resistance of the support cycle.

[0028] Optionally, the pressure criterion is determined based on the working resistance of the support and the end-cycle resistance of the support, including:

[0029] The first pressure criterion is obtained by summing the time-weighted working resistance and the mean square error of the support working resistance.

[0030] The second pressure criterion is obtained by summing the time-weighted working resistance and the root mean square error of the support at the end of the cycle.

[0031] The pressure criterion is formed by combining the first pressure criterion and the second pressure criterion.

[0032] Optionally, the time-weighted working resistance of the support is calculated by the curve of the support working resistance and time. Its value is the area enclosed by the curve divided by the total time of force application. The area enclosed by the curve is divided into multiple small curved trapezoids to calculate the time-weighted working resistance of the support.

[0033] The time-weighted working resistance of the support at the end of the cycle is calculated by the curve of the support at the end of the cycle and time. Its value is the area enclosed by the curve divided by the total time of force application. The area enclosed by the curve is divided into multiple small curved trapezoids to calculate the time-weighted working resistance of the support at the end of the cycle.

[0034] The time-weighted working resistance of the support or the time-weighted working resistance at the end of the support cycle. The calculation formula is:

[0035]

[0036] In the above formula, t1, t2, t n These represent the durations corresponding to the small trapezoids on the curve representing the working resistance of the support, or the durations corresponding to the small trapezoids on the curve representing the resistance at the end of the support cycle, p0, p1, ... p n These represent the stent working resistance or stent cycle end resistance at different monitoring times;

[0037] The root mean square deviation σ of the working resistance of the support or the end-cycle resistance of the support p The calculation formula is:

[0038]

[0039] In the above formula, p0, p1, ... pn These represent the stent working resistance or stent cycle end resistance at different monitoring times;

[0040] The calculation formula for the first pressure criterion or the second pressure criterion is as follows:

[0041]

[0042] In the above formula, P represents the standard value of the first pressure criterion or the second pressure criterion, m represents the mean coefficient, and n represents the variance coefficient.

[0043] Optionally, historical data is obtained based on the aforementioned pressure criterion, including:

[0044] The working resistance curve and cycle end resistance curve of each support are statistically analyzed. When they simultaneously reach their respective pressure criteria, it is determined that the support has experienced periodic pressure. The historical statistical results of the pressure step distance of the top plate of the support are obtained. The historical statistical results include: pressure start time, pressure end time, and pressure step distance.

[0045] The historical data is derived from all historical statistical results.

[0046] Optionally, the next pressure prediction area range and pressure step distance are predicted using the pressure prediction model, including:

[0047] Using the aforementioned pressure prediction model, combined with the most recent cycle pressure step distance, pressure time, and working face advance information during the pressure period for each support, the start time and pressure step distance of the next pressure for each support can be predicted.

[0048] Calculate the start time and step distance of the next compression for all stents;

[0049] If the difference in the start time of the next pressure on adjacent supports is less than a preset value, it is determined that it is the same pressure, and the predicted area range of the next pressure is obtained based on the start time of the next pressure.

[0050] Based on the predicted area range of the next pressure, determine whether the next pressure will be a large-cycle pressure, a small-cycle pressure, a local pressure, or a pressure on the entire working face.

[0051] Based on the aforementioned pressure criteria, the historical pressure step distance for each stent is obtained. Statistical analysis is performed on the historical pressure step distance for each stent, and the pressure step distance with the highest weight is taken as the next pressure step distance for each stent.

[0052] Optionally, after obtaining historical data based on the aforementioned pressure criterion, the method further includes:

[0053] Using the aforementioned pressure prediction model and combining it with the historical data, the historical pressure start time and pressure step distance for each stent are obtained.

[0054] Statistically analyze the historical initiation time and next initiation step distance of all stents;

[0055] If the difference in the historical pressure start time between adjacent supports is less than a preset value, it is determined to be the same pressure event, and the influence range of the historical pressure event is obtained based on the historical pressure start time.

[0056] Based on the historical impact range, determine whether the historical pressure was a large-cycle pressure, a small-cycle pressure, a local pressure, or a pressure on the entire working face.

[0057] The historical compression step distance of each stent was statistically analyzed, and the region with the highest weight was taken as the historical compression step distance of each stent. The historical minimum cycle compression step distance, the historical maximum compression duration, and the historical maximum compression influence range were also statistically analyzed.

[0058] This invention provides a periodic pressure analysis system for coal mine longwall faces, the system comprising:

[0059] The data acquisition module is used to collect the working resistance of the support structure at the working face.

[0060] The extraction module is used to extract the end-cycle resistance of the support based on the working resistance of the support.

[0061] The pressure criterion module is used to determine the pressure criterion based on the working resistance of the support and the end-cycle resistance of the support.

[0062] The historical data module is used to obtain historical data based on the pressure criterion, and the historical data includes: the occurrence period of pressure, the pressure time, and the pressure step distance;

[0063] The pressure prediction model module is used to establish a pressure prediction model based on the historical data. The pressure prediction model is used to predict the pressure step distance and pressure duration of all stents.

[0064] The prediction module is used to predict the range of the next pressure prediction area and the pressure step distance using the pressure prediction model.

[0065] Optionally, the data acquisition module is specifically used for:

[0066] The pressure values ​​of individual struts of the support were collected;

[0067] The working resistance of the support is calculated based on the pressure value of the individual support column.

[0068] The formula for calculating the working resistance of the support is as follows:

[0069]

[0070] In the above formula, P represents the working resistance of the support, p1 represents the pressure value of the left support, p2 represents the pressure value of the right support, and d represents the inner diameter of the single support.

[0071] Optionally, the extraction module includes:

[0072] The extraction submodule is used to process the working resistance of the stent using the minimum threshold method and combined with the resistance change gradient method to extract the end-cycle resistance of the stent.

[0073] Optionally, the extraction submodule is specifically used for:

[0074] Set the minimum working resistance threshold after the support unloading and lowering stage;

[0075] Set the difference in working resistance of the support before and after the support unloading and lowering stage;

[0076] Select the previous working resistance that is less than the minimum working resistance threshold from all the working resistances of the stents, and the monitoring time corresponding to the previous working resistance is the previous monitoring time;

[0077] The average descent time of the support was calculated based on the sampling interval and the actual descent time of the support at the working face.

[0078] Calculate the subsequent working resistance corresponding to the subsequent monitoring time, wherein the subsequent monitoring time is the difference between the previous monitoring time and the average descent time of the support;

[0079] If the difference between the subsequent working resistance and the preceding working resistance is greater than the difference in the working resistance of the support, then the maximum supporting force provided by the support to the top plate before the support is unloaded and lowered is obtained, and this maximum supporting force is the end resistance of the support cycle.

[0080] Optionally, the pressure determination module is specifically used for:

[0081] The first pressure criterion is obtained by summing the time-weighted working resistance and the mean square error of the support working resistance.

[0082] The second pressure criterion is obtained by summing the time-weighted working resistance and the root mean square error of the support at the end of the cycle.

[0083] The pressure criterion is formed by combining the first pressure criterion and the second pressure criterion;

[0084] The time-weighted working resistance of the support is calculated by the curve of the support working resistance and time. Its value is the area enclosed by the curve divided by the total time of force application. The area enclosed by the curve is divided into multiple small curved trapezoids to calculate the time-weighted working resistance of the support.

[0085] The time-weighted working resistance of the support at the end of the cycle is calculated by the curve of the support at the end of the cycle and time. Its value is the area enclosed by the curve divided by the total time of force application. The area enclosed by the curve is divided into multiple small curved trapezoids to calculate the time-weighted working resistance of the support at the end of the cycle.

[0086] The time-weighted working resistance of the support or the time-weighted working resistance at the end of the support cycle. The calculation formula is:

[0087]

[0088] In the above formula, t1, t2, t n These represent the durations corresponding to the small trapezoids on the curve representing the working resistance of the support, or the durations corresponding to the small trapezoids on the curve representing the resistance at the end of the support cycle, p0, p1, ... p n These represent the stent working resistance or stent cycle end resistance at different monitoring times;

[0089] The root mean square deviation σ of the working resistance of the support or the end-cycle resistance of the support p The calculation formula is:

[0090]

[0091] In the above formula, p0, p1, ... p n These represent the stent working resistance or stent cycle end resistance at different monitoring times;

[0092] The calculation formula for the first pressure criterion or the second pressure criterion is as follows:

[0093]

[0094] In the above formula, P represents the standard value of the first pressure criterion or the second pressure criterion, m represents the mean coefficient, and n represents the variance coefficient.

[0095] Optionally, the historical data module is specifically used for:

[0096] The working resistance curve and cycle end resistance curve of each support are statistically analyzed. When they simultaneously reach their respective pressure criteria, it is determined that the support has experienced periodic pressure. The historical statistical results of the pressure step distance of the top plate of the support are obtained. The historical statistical results include: pressure start time, pressure end time, and pressure step distance.

[0097] The historical data is derived from all historical statistical results.

[0098] Optionally, the prediction module is specifically used for:

[0099] Using the aforementioned pressure prediction model, combined with the most recent cycle pressure step distance, pressure time, and working face advance information during the pressure period for each support, the start time and pressure step distance of the next pressure for each support can be predicted.

[0100] Calculate the start time and step distance of the next compression for all stents;

[0101] If the difference in the start time of the next pressure on adjacent supports is less than a preset value, it is determined that it is the same pressure, and the predicted area range of the next pressure is obtained based on the start time of the next pressure.

[0102] Based on the predicted area range of the next pressure, determine whether the next pressure will be a large-cycle pressure, a small-cycle pressure, a local pressure, or a pressure on the entire working face.

[0103] Based on the aforementioned pressure criteria, the historical pressure step distance for each stent is obtained. Statistical analysis is performed on the historical pressure step distance for each stent, and the pressure step distance with the highest weight is taken as the next pressure step distance for each stent.

[0104] Optionally, the coal mine longwall face periodic pressure analysis system further includes: a historical analysis module;

[0105] The historical analysis module is specifically used for:

[0106] Using the aforementioned pressure prediction model and combining it with the historical data, the historical pressure start time and pressure step distance for each stent are obtained.

[0107] Statistically analyze the historical initiation time and next initiation step distance of all stents;

[0108] If the difference in the historical pressure start time between adjacent supports is less than a preset value, it is determined to be the same pressure event, and the influence range of the historical pressure event is obtained based on the historical pressure start time.

[0109] Based on the historical impact range, determine whether the historical pressure was a large-cycle pressure, a small-cycle pressure, a local pressure, or a pressure on the entire working face.

[0110] The historical compression step distance of each stent was statistically analyzed, and the region with the highest weight was taken as the historical compression step distance of each stent. The historical minimum cycle compression step distance, the historical maximum compression duration, and the historical maximum compression influence range were also statistically analyzed.

[0111] The method for analyzing periodic pressure in coal mine longwall faces provided by this invention first collects the working resistance of the supports at the working face; then extracts the end-cycle resistance of the supports based on the working resistance; next, it determines the pressure inrush criterion based on the working resistance and the end-cycle resistance of the supports; then, it obtains historical data based on the pressure inrush criterion, which includes: the occurrence of periodic pressure, the time of pressure inrush, and the pressure inrush step distance; it establishes a pressure inrush prediction model based on the historical data, which is used to predict the pressure inrush step distance and duration of all supports; finally, it uses the pressure inrush prediction model to predict the prediction area and pressure inrush step distance of the next pressure inrush.

[0112] This invention creatively proposes an effective method for in-depth mining and analysis of support column resistance data. It can automatically extract the support's end-cycle resistance, calculate the support's pressure inrush criteria, and extract historical periodic pressure inrush characteristics such as pressure inrush step distance, pressure inrush start time, and pressure inrush duration in real time. This provides a data sample set for step distance prediction models, improving the identification rate of abnormal mine pressure manifestations during mining. It enables historical statistical analysis of periodic pressure inrushes, allowing for the identification of the minimum periodic pressure inrush step distance, maximum pressure inrush duration, and maximum pressure inrush impact range during the mining process. This provides decision support for daily production management of the working face, assisting in achieving less-manned or unmanned mining. The entire method only requires connection to the working face support resistance monitoring system to complete the analysis and early warning of periodic pressure inrushes. It has good applicability and scalability in other coal mines and is highly practical. Attached Figure Description

[0113] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0114] Figure 1 This is a flowchart of a method for periodic pressure analysis of coal mining faces based on video recognition, according to an embodiment of the present invention.

[0115] Figure 2 This is a superior control process for the periodic pressure analysis method of coal mine longwall face in the embodiments of the present invention;

[0116] Figure 3 This is a block diagram of a coal mine longwall face periodic pressure analysis system based on video recognition for coal mining machinery and scraper conveyors, according to an embodiment of the present invention. Detailed Implementation

[0117] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention, and are only some, not all, embodiments of the present invention, and are not intended to limit the present invention.

[0118] Reference Figure 1 The flowchart illustrates a method for periodic pressure analysis of a coal mine longwall face according to an embodiment of the present invention. This method includes:

[0119] Step 101: Collect the working resistance of the support at the working face.

[0120] First, it is necessary to collect the working resistance of the support structure at the working face. Ideally, the working resistance of the support structure should be expressed as the pressure of the entire support structure. However, the data collected by the actual monitoring system or equipment is usually the pressure value of a single support column. Therefore, the pressure value of a single support column can be collected first, and then the working resistance of the support structure can be calculated based on the pressure value of the single support column.

[0121] The formula for calculating the working resistance of the stent is as follows:

[0122]

[0123] In the above formula, P represents the working resistance of the support, in kN; p1 represents the pressure value of the left support column; p2 represents the pressure value of the right support column, both in MPa; and d represents the inner diameter of a single support column, in meters.

[0124] Step 102: Extract the end-cycle resistance of the stent based on the working resistance of the stent.

[0125] After obtaining the stent's working resistance, the stent's end-cycle resistance is then extracted based on this resistance. There are several methods for extracting the stent's end-cycle resistance, one of the preferred methods being:

[0126] The minimum threshold method, combined with the resistance change gradient method, was used to process the working resistance of the support system to extract the resistance at the end of the support cycle. The resistance at the end of the support cycle is the maximum supporting force provided by the support to the roof at the end of the load-bearing stage. Specifically:

[0127] Set the minimum working resistance threshold p after the support unloading and lowering stage. min Set the difference in working resistance ΔP between the support and the support before and after the unloading and lowering stage; select the support with working resistance less than the minimum working resistance threshold p from all the support working resistances. min The front working resistance p after The working resistance p afterThe corresponding monitoring time is the previous monitoring time t. after .

[0128] Based on the sampling interval and the actual support descent time at the working face, the average support descent time Δt was calculated; the monitoring time t after calculation was then adjusted. before The corresponding working resistance p before The so-called post-monitoring time refers to the pre-monitoring time t. after The difference between the support and the average descent time Δt (i.e., t) after -Δt=t before If the subsequent working resistance p before With the previous working resistance p after If the difference between the values ​​is greater than the difference in the working resistance of the support ΔP, then the maximum supporting force provided by the support to the top plate before the support is unloaded and lowered is obtained. This maximum supporting force is the resistance at the end of the support cycle.

[0129] Combination Figure 2 The diagram illustrates an exemplary support system's resistance at the end of a cycle. The horizontal axis represents time (t), and the vertical axis represents the support's working resistance (P). The system is divided into five stages: I. Initial pressurization stage; II. Stable bearing stage; III. Coal cutting impact stage; IV. Adjacent support relocation and resistance increase stage; and V. Unloading and lowering stage. The diagram also indicates the minimum working resistance threshold (p) after the unloading and lowering stage. min Front working resistance p after Front working resistance p after Corresponding pre-monitoring time t after Post-monitoring time t before and its corresponding rear support working resistance p before .

[0130] Step 103: Determine the pressure criterion based on the working resistance of the stent and the end-cycle resistance of the stent.

[0131] After obtaining the stent's working resistance and the stent's end-cycle resistance, the pressure criterion is determined based on these two resistances. A preferred method for determining the pressure criterion includes:

[0132] The first pressure criterion is obtained by calculating the sum of the time-weighted working resistance and the mean square error of the stent's working resistance; the second pressure criterion is obtained by calculating the sum of the time-weighted working resistance and the mean square error of the stent's end-cycle resistance; the pressure criterion is formed by combining the first and second pressure criters.

[0133] Since the time-weighted average resistance is the average working resistance of the support structure calculated using time as the weighting factor, the time-weighted working resistance of the support structure can be calculated using the Pt curve of the support structure's working resistance and time. Its value is the area enclosed by the Pt curve divided by the total time the force is applied. To facilitate calculation, the area enclosed by the Pt curve can be divided into multiple small curved trapezoids (theoretically, the more the better, but the greater the computational load; the specific number of small curved trapezoids can be determined based on actual needs), thereby calculating the time-weighted working resistance of the support structure.

[0134] Similar to the time-weighted working resistance of the stent, the time-weighted working resistance at the end of the stent cycle can be calculated using the curve of the stent's end-cycle resistance versus time. Its value is the area enclosed by the curve divided by the total time of force application. The area enclosed by the curve is divided into multiple small curved trapezoids to calculate the time-weighted working resistance at the end of the stent cycle.

[0135] Since the formulas for calculating the time-weighted working resistance of the stent and the time-weighted working resistance at the end of the stent cycle are exactly the same, they will not be repeated here. Simply calculate them separately using the formulas below. Time-weighted working resistance of stent or time-weighted working resistance at the end of the stent cycle The calculation formula is:

[0136]

[0137] In the above formula, t1, t2, t n These represent the durations corresponding to the small trapezoids on the curve representing the working resistance of the stent, or the durations corresponding to the small trapezoids on the curve representing the resistance at the end of the stent cycle, p0, p1, ... p n These represent the stent working resistance or stent cycle end resistance at different monitoring times.

[0138] The root mean square deviation σ of the stent's working resistance or the stent's end-cycle resistance p The calculation formula is:

[0139]

[0140] In the above formula, p0, p1, ... p n These represent the stent working resistance or stent cycle end resistance at different monitoring times;

[0141] The formulas for calculating the first or second pressure criterion are as follows:

[0142]

[0143] In the above formula, P represents the standard value of the first or second pressure criterion, m represents the mean coefficient (generally taken as 1), and n represents the variance coefficient (generally taken as 0.1 to 2).

[0144] Step 104: Obtain historical data based on the pressure criterion. The historical data includes: the occurrence period of pressure, the pressure time, and the pressure step distance.

[0145] After obtaining the incoming pressure criterion, historical data is derived based on it. This historical data includes: the occurrence period of incoming pressure, the time of incoming pressure, and the step distance of incoming pressure. A better approach is:

[0146] The working resistance curve and end-cycle resistance curve of each support can be statistically analyzed. When they simultaneously reach their respective pressure criteria, it is determined that the support has experienced periodic pressure. That is, if the working resistance curve of any support reaches the first pressure criterion and the end-cycle resistance curve of the support reaches the second pressure criterion, then the support has experienced periodic pressure. If either one is not met, it is considered that the support has not experienced periodic pressure.

[0147] Based on the above method, the historical statistical results of the top plate pressure step distance of the support can be obtained. These historical statistical results include: pressure start time, pressure end time, and pressure step distance. Finally, historical data is obtained based on all historical statistical results (i.e., the historical statistical results corresponding to all supports).

[0148] Step 105: Establish a pressure prediction model based on historical data. The pressure prediction model is used to predict the pressure step distance and pressure duration of all stents.

[0149] After obtaining historical data, a pressure prediction model can be built based on this data. This model is used to predict the pressure step distance and duration of all stents. There are various methods for building a pressure prediction model, such as using neural network models or AI. Naturally, it is understandable that building a pressure prediction model requires processes such as training, calibration, and iteration to ensure its accuracy.

[0150] Step 106: Use the pressure prediction model to predict the range of the next pressure prediction area and the pressure step distance.

[0151] Once the pressure prediction model is established, it can be used to predict the range of the next pressure event and the pressure step distance. Specifically:

[0152] Using the pressure prediction model, combined with the most recent cycle pressure step distance, pressure time, and working face advance information during the pressure period for each support, the start time and pressure step distance of the next pressure for each support are predicted; the start time and pressure step distance of the next pressure for all supports are statistically analyzed.

[0153] If the difference in the start time of the next pressure surge of adjacent supports is less than a preset value, it is determined to be the same pressure surge, rather than two separate pressure surges. Conversely, if the difference in the start time of the next pressure surge of adjacent supports is not less than the preset value, it is determined to be different pressure surges. The predicted area for the next pressure surge is also determined based on the start time of the next pressure surge.

[0154] After obtaining the predicted area range, it is possible to determine whether the next pressure will be a large-cycle pressure, a small-cycle pressure, a local pressure, or a pressure on the entire working face, based on the predicted area range of the next pressure. Furthermore, based on the pressure criteria, the historical pressure step distance of each support is obtained, and the historical pressure step distance of each support is statistically analyzed. The pressure step distance with the highest weight is taken as the next pressure step distance of each support.

[0155] The prediction of periodic pressure at the coal mine longwall face can be achieved through steps 101 to 106 described above. Furthermore, after obtaining historical data based on the pressure criterion, the analysis of this historical data is also included.

[0156] By using the pressure prediction model and combining historical data, the historical pressure start time and pressure step distance for each stent are obtained; the historical pressure start time and next pressure step distance for all stents are statistically analyzed.

[0157] If the difference in the historical pressure start time between adjacent supports is less than a preset value, it is determined to be the same pressure event, and the historical pressure influence range is obtained based on the historical pressure start time. Based on the historical pressure influence range, it is determined whether the historical pressure is a large-cycle pressure, a small-cycle pressure, a local pressure, or a pressure event affecting the entire working face. Furthermore, the historical pressure step distance for each support is calculated, and the area with the highest weight is taken as the historical pressure step distance for each support. The historical minimum cycle pressure step distance, the historical maximum pressure duration, and the historical maximum pressure influence range are also calculated. The analysis of historical data is beneficial for expanding the subsequent data sample set and further improving the accuracy of the pressure prediction model. At the same time, it provides information such as the minimum cycle pressure step distance, the maximum pressure duration, and the maximum pressure influence range during the mining process of the longwall face, and also provides decision support for the daily production management of the working face, assisting in the realization of unmanned or minimally manned mining.

[0158] In this embodiment of the invention, based on the above-mentioned method for periodic pressure analysis of coal mine longwall faces, a system for periodic pressure analysis of coal mine longwall faces is also proposed, referring to... Figure 3 The block diagram shown is of a periodic pressure analysis system for a coal mine longwall face, which includes:

[0159] Data acquisition module 310 is used to collect the working resistance of the support at the working face;

[0160] Extraction module 320 is used to extract the end-cycle resistance of the support based on the working resistance of the support;

[0161] The pressure criterion module 330 is used to determine the pressure criterion based on the working resistance of the support and the end-cycle resistance of the support.

[0162] Historical data module 340 is used to obtain historical data based on the pressure criterion, wherein the historical data includes: the occurrence periodic pressure, the pressure time, and the pressure step distance;

[0163] The pressure prediction model module 350 is used to establish a pressure prediction model based on the historical data. The pressure prediction model is used to predict the pressure step distance and pressure duration of all stents.

[0164] The prediction module 360 ​​is used to predict the range of the next pressure prediction area and the pressure step distance using the pressure prediction model.

[0165] Optionally, the data acquisition module 310 is specifically used for:

[0166] The pressure values ​​of individual struts of the support were collected;

[0167] The working resistance of the support is calculated based on the pressure value of the individual support column.

[0168] The formula for calculating the working resistance of the support is as follows:

[0169]

[0170] In the above formula, P represents the working resistance of the support, p1 represents the pressure value of the left support, p2 represents the pressure value of the right support, and d represents the inner diameter of the single support.

[0171] Optionally, the extraction module 320 includes:

[0172] The extraction submodule is used to process the working resistance of the stent using the minimum threshold method and combined with the resistance change gradient method to extract the end-cycle resistance of the stent.

[0173] Optionally, the extraction submodule is specifically used for:

[0174] Set the minimum working resistance threshold after the support unloading and lowering stage;

[0175] Set the difference in working resistance of the support before and after the support unloading and lowering stage;

[0176] Select the previous working resistance that is less than the minimum working resistance threshold from all the working resistances of the stents, and the monitoring time corresponding to the previous working resistance is the previous monitoring time;

[0177] The average descent time of the support was calculated based on the sampling interval and the actual descent time of the support at the working face.

[0178] Calculate the subsequent working resistance corresponding to the subsequent monitoring time, wherein the subsequent monitoring time is the difference between the previous monitoring time and the average descent time of the support;

[0179] If the difference between the subsequent working resistance and the preceding working resistance is greater than the difference in the working resistance of the support, then the maximum supporting force provided by the support to the top plate before the support is unloaded and lowered is obtained, and this maximum supporting force is the end resistance of the support cycle.

[0180] Optionally, the pressure determination module 330 is specifically used for:

[0181] The first pressure criterion is obtained by summing the time-weighted working resistance and the mean square error of the support working resistance.

[0182] The second pressure criterion is obtained by summing the time-weighted working resistance and the root mean square error of the support at the end of the cycle.

[0183] The pressure criterion is formed by combining the first pressure criterion and the second pressure criterion;

[0184] The time-weighted working resistance of the support is calculated by the curve of the support working resistance and time. Its value is the area enclosed by the curve divided by the total time of force application. The area enclosed by the curve is divided into multiple small curved trapezoids to calculate the time-weighted working resistance of the support.

[0185] The time-weighted working resistance of the support at the end of the cycle is calculated by the curve of the support at the end of the cycle and time. Its value is the area enclosed by the curve divided by the total time of force application. The area enclosed by the curve is divided into multiple small curved trapezoids to calculate the time-weighted working resistance of the support at the end of the cycle.

[0186] The time-weighted working resistance of the support or the time-weighted working resistance at the end of the support cycle. The calculation formula is:

[0187]

[0188] In the above formula, t1, t2, t n These represent the durations corresponding to the small trapezoids on the curve representing the working resistance of the support, or the durations corresponding to the small trapezoids on the curve representing the resistance at the end of the support cycle, p0, p1, ... p n These represent the stent working resistance or stent cycle end resistance at different monitoring times;

[0189] The root mean square deviation σ of the working resistance of the support or the end-cycle resistance of the support p The calculation formula is:

[0190]

[0191] In the above formula, p0, p1, ... p n These represent the stent working resistance or stent cycle end resistance at different monitoring times;

[0192] The calculation formula for the first pressure criterion or the second pressure criterion is as follows:

[0193]

[0194] In the above formula, P represents the standard value of the first pressure criterion or the second pressure criterion, m represents the mean coefficient, and n represents the variance coefficient.

[0195] Optionally, the historical data module 340 is specifically used for:

[0196] The working resistance curve and cycle end resistance curve of each support are statistically analyzed. When they simultaneously reach their respective pressure criteria, it is determined that the support has experienced periodic pressure. The historical statistical results of the pressure step distance of the top plate of the support are obtained. The historical statistical results include: pressure start time, pressure end time, and pressure step distance.

[0197] The historical data is derived from all historical statistical results.

[0198] Optionally, the prediction module 360 ​​is specifically used for:

[0199] Using the aforementioned pressure prediction model, combined with the most recent cycle pressure step distance, pressure time, and working face advance information during the pressure period for each support, the start time and pressure step distance of the next pressure for each support can be predicted.

[0200] Calculate the start time and step distance of the next compression for all stents;

[0201] If the difference in the start time of the next pressure on adjacent supports is less than a preset value, it is determined that it is the same pressure, and the predicted area range of the next pressure is obtained based on the start time of the next pressure.

[0202] Based on the predicted area range of the next pressure, determine whether the next pressure will be a large-cycle pressure, a small-cycle pressure, a local pressure, or a pressure on the entire working face.

[0203] Based on the aforementioned pressure criteria, the historical pressure step distance for each stent is obtained. Statistical analysis is performed on the historical pressure step distance for each stent, and the pressure step distance with the highest weight is taken as the next pressure step distance for each stent.

[0204] Optionally, the coal mine longwall face periodic pressure analysis system further includes: a historical analysis module;

[0205] The historical analysis module is specifically used for:

[0206] Using the aforementioned pressure prediction model and combining it with the historical data, the historical pressure start time and pressure step distance for each stent are obtained.

[0207] Statistically analyze the historical initiation time and next initiation step distance of all stents;

[0208] If the difference in the historical pressure start time between adjacent supports is less than a preset value, it is determined to be the same pressure event, and the influence range of the historical pressure event is obtained based on the historical pressure start time.

[0209] Based on the historical impact range, determine whether the historical pressure was a large-cycle pressure, a small-cycle pressure, a local pressure, or a pressure on the entire working face.

[0210] The historical compression step distance of each stent was statistically analyzed, and the region with the highest weight was taken as the historical compression step distance of each stent. The historical minimum cycle compression step distance, the historical maximum compression duration, and the historical maximum compression influence range were also statistically analyzed.

[0211] In summary, the coal mine longwall face periodic pressure analysis method provided by this invention first collects the working resistance of the supports at the working face; extracts the end-cycle resistance of the supports based on the working resistance; then determines the pressure criterion based on the working resistance and the end-cycle resistance; next, obtains historical data based on the pressure criterion, which includes: the occurrence of periodic pressure, the pressure time, and the pressure step distance; establishes a pressure prediction model based on the historical data, which is used to predict the pressure step distance and duration of all supports; finally, uses the pressure prediction model to predict the next pressure prediction area and pressure step distance.

[0212] This invention creatively proposes an effective method for in-depth mining and analysis of support column resistance data. It can automatically extract the support's end-cycle resistance, calculate the support's pressure inrush criteria, and extract historical periodic pressure inrush characteristics such as pressure inrush step distance, pressure inrush start time, and pressure inrush duration in real time. This provides a data sample set for step distance prediction models, improving the identification rate of abnormal mine pressure manifestations during mining. It enables historical statistical analysis of periodic pressure inrushes, allowing for the identification of the minimum periodic pressure inrush step distance, maximum pressure inrush duration, and maximum pressure inrush impact range during the mining process. This provides decision support for daily production management of the working face, assisting in achieving less-manned or unmanned mining. The entire method only requires connection to the working face support resistance monitoring system to complete the analysis and early warning of periodic pressure inrushes. It has good applicability and scalability in other coal mines and is highly practical.

[0213] Although preferred embodiments of the present invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the embodiments of the present invention.

[0214] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or terminal device. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or terminal device that includes said element.

[0215] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention 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 the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

Claims

1. A method for periodic pressure analysis of a coal mine longwall face, characterized in that, The method for periodic pressure analysis of coal mine longwall faces includes: The working resistance of the support structure at the data acquisition working surface; The minimum threshold method, combined with the resistance change gradient method, is used to process the working resistance of the support, extracting the support's cycle-end resistance. This includes: setting a minimum working resistance threshold after the support unloading and lowering stage; setting the difference in working resistance before and after the support unloading and lowering stage; selecting the working resistance less than the minimum working resistance threshold from all support working resistances, with the monitoring time corresponding to the previous working resistance being the previous monitoring time; calculating the average lowering time of the support based on the sampling interval and the actual support lowering time on the working face; calculating the subsequent working resistance corresponding to the subsequent monitoring time, where the subsequent monitoring time is the difference between the previous monitoring time and the average lowering time; if the difference between the subsequent working resistance and the previous working resistance is greater than the difference in support working resistance, then the maximum supporting force provided by the support to the top plate before unloading and lowering is obtained, and this maximum supporting force is the support's cycle-end resistance. The pressure criterion is determined based on the working resistance of the support and the end-cycle resistance of the support. Historical data is obtained based on the pressure criterion, and the historical data includes: the occurrence of periodic pressure, the pressure time, and the pressure step distance; An inrush prediction model is established based on the historical data. The inrush prediction model is used to predict the inrush step distance and inrush duration of all stents. The predicted pressure area and pressure step distance are obtained by using the pressure prediction model. The process of collecting the working resistance of the support structure at the working face includes: collecting the pressure value of a single support column; calculating the working resistance of the support structure based on the pressure value of the single support column; wherein the calculation formula for the working resistance of the support structure is: In the above formula, P This indicates the working resistance of the support. p 1 indicates the pressure value of the left support column. p 2 indicates the pressure value of the right support column. d This indicates the inner diameter of the individual support column.

2. The method for periodic pressure analysis of coal mine longwall faces according to claim 1, characterized in that, The pressure criterion is determined based on the working resistance of the support and the end-cycle resistance of the support, including: The first pressure criterion is obtained by summing the time-weighted working resistance and the mean square error of the support working resistance. The second pressure criterion is obtained by summing the time-weighted working resistance and the root mean square error of the support at the end of the cycle. The pressure criterion is formed by combining the first pressure criterion and the second pressure criterion.

3. The method for periodic pressure analysis of coal mine longwall faces according to claim 2, characterized in that, The time-weighted working resistance of the support is calculated by the curve of the support working resistance and time. Its value is the area enclosed by the curve divided by the total time of force application. The area enclosed by the curve is divided into multiple small curved trapezoids to calculate the time-weighted working resistance of the support. The time-weighted working resistance of the support at the end of the cycle is calculated by the curve of the support at the end of the cycle and time. Its value is the area enclosed by the curve divided by the total time of force application. The area enclosed by the curve is divided into multiple small curved trapezoids to calculate the time-weighted working resistance of the support at the end of the cycle. The time-weighted working resistance of the support or the time-weighted working resistance at the end of the support cycle. The calculation formula is: In the above formula, These represent the duration corresponding to each small trapezoid in the curve representing the working resistance of the support, or the duration corresponding to each small trapezoid in the curve representing the resistance at the end of the support cycle. These represent the stent working resistance or stent cycle end resistance at different monitoring times; The mean square deviation of the working resistance of the support or the end-cycle resistance of the support. The calculation formula is: In the above formula, These represent the stent working resistance or stent cycle end resistance at different monitoring times; The calculation formula for the first pressure criterion or the second pressure criterion is as follows: In the above formula, This represents the standard value of either the first pressure criterion or the second pressure criterion. Represents the mean coefficient. This represents the variance coefficient.

4. The method for periodic pressure analysis of coal mine longwall faces according to claim 1, characterized in that, Historical data obtained based on the aforementioned pressure criterion includes: The working resistance curve and cycle end resistance curve of each support are statistically analyzed. When they simultaneously reach their respective pressure criteria, it is determined that the support has experienced periodic pressure. The historical statistical results of the pressure step distance of the top plate of the support are obtained. The historical statistical results include: pressure start time, pressure end time, and pressure step distance. The historical data is derived from all historical statistical results.

5. The method for periodic pressure analysis of coal mine longwall faces according to claim 1, characterized in that, The predicted area and step size for the next pressure event are obtained using the pressure prediction model, including: Using the aforementioned pressure prediction model, combined with the most recent cycle pressure step distance, pressure time, and working face advance information during the pressure period for each support, the start time and pressure step distance of the next pressure for each support can be predicted. Calculate the start time and step distance of the next compression for all stents; If the difference in the start time of the next pressure on adjacent supports is less than a preset value, it is determined that it is the same pressure, and the predicted area range of the next pressure is obtained based on the start time of the next pressure. Based on the predicted area range of the next pressure, determine whether the next pressure will be a large-cycle pressure, a small-cycle pressure, a local pressure, or a pressure on the entire working face. Based on the aforementioned pressure criteria, the historical pressure step distance for each stent is obtained. Statistical analysis is performed on the historical pressure step distance for each stent, and the pressure step distance with the highest weight is taken as the next pressure step distance for each stent.

6. The method for periodic pressure analysis of coal mine longwall faces according to claim 1, characterized in that, After obtaining historical data based on the aforementioned pressure criterion, the following is also included: Using the aforementioned pressure prediction model and combining it with the historical data, the historical pressure start time and pressure step distance for each stent are obtained. Statistically analyze the historical initiation time and next initiation step distance of all stents; If the difference in the historical pressure start time between adjacent supports is less than a preset value, it is determined to be the same pressure event, and the influence range of the historical pressure event is obtained based on the historical pressure start time. Based on the historical impact range, determine whether the historical pressure was a large-cycle pressure, a small-cycle pressure, a local pressure, or a pressure on the entire working face. The historical compression step distance of each stent was statistically analyzed, and the region with the highest weight was taken as the historical compression step distance of each stent. The historical minimum cycle compression step distance, the historical maximum compression duration, and the historical maximum compression influence range were also statistically analyzed.

7. A periodic pressure analysis system for coal mine longwall faces, characterized in that, The coal mine longwall face periodic pressure analysis system includes: The data acquisition module is used to collect the working resistance of the support structure at the working face. The extraction module is used to process the working resistance of the support using a minimum threshold method combined with a resistance change gradient method to extract the final resistance of the support cycle. Specifically, it is used to: set a minimum working resistance threshold after the support unloading and lowering stage; set the difference in working resistance before and after the support unloading and lowering stage; select the working resistance that is less than the minimum working resistance threshold from all the working resistances of the support, and the monitoring time corresponding to the working resistance is the previous monitoring time; calculate the average lowering time of the support based on the sampling interval and the actual lowering time of the support on the working face; calculate the subsequent working resistance corresponding to the subsequent monitoring time, and the subsequent monitoring time is the difference between the previous monitoring time and the average lowering time of the support; if the difference between the subsequent working resistance and the previous working resistance is greater than the difference in working resistance of the support, then the maximum supporting force provided by the support to the top plate before the support unloading and lowering is obtained, and this maximum supporting force is the final resistance of the support cycle. The pressure criterion module is used to determine the pressure criterion based on the working resistance of the support and the end-cycle resistance of the support. The historical data module is used to obtain historical data based on the pressure criterion, and the historical data includes: the occurrence period of pressure, the pressure time, and the pressure step distance; The pressure prediction model module is used to establish a pressure prediction model based on the historical data. The pressure prediction model is used to predict the pressure step distance and pressure duration of all stents. The prediction module is used to predict the next pressure prediction area range and pressure step distance using the pressure prediction model. Specifically, the data acquisition module is used for: The pressure values ​​of individual struts of the support were collected; The working resistance of the support is calculated based on the pressure value of the individual support column. The formula for calculating the working resistance of the support is as follows: In the above formula, P This indicates the working resistance of the support. p 1 indicates the pressure value of the left support column. p 2 indicates the pressure value of the right support column. d This indicates the inner diameter of the individual support column.

Images