Method and system for analyzing periodic weighting of coal mine stope face

Abstract

The invention provides a method and a system for analyzing periodic weighting of a coal mine stope face, and relates to the field of coal mine intelligent prediction. The method includes: collecting working face support working resistance data; a minimum threshold method is combined with a resistance change gradient method to extract circulation end resistance; the sum of the time weighted working resistance and the mean square deviation value of the working resistance and the circulation end resistance of the support serves as a weighting criterion; when the working resistance curve and the circulating end resistance curve of the support simultaneously reach respective weighting criteria, weighting is considered to occur, and weighting time and step pitch are recorded; establishing a weighting step prediction model, and predicting weighting steps and weighting durations of all supports; if the weighting prediction time difference of the adjacent supports is smaller than a set threshold value, determining that weighting is the same time, and meanwhile, calculating a weighting prediction area range and a weighting step pitch of this time; the minimum period weighting step pitch, the maximum weighting duration and the maximum weighting influence range are analyzed according to the historical weighting prediction result. The method can accurately calculate the periodic weighting rule of the working face.

Description

Technical Field

[0001] The present invention relates to the field of intelligent prediction of coal mines, in particular to a method for analyzing periodic pressure on a coal mine working face and a system for analyzing periodic pressure on a coal mine working face. Background Art

[0002] Over the years, roof accidents and roof disasters in my country's coal mines have been at the forefront of various coal mine accidents due to their wide range of locations and difficulty in control. With the gradual increase in the depth and intensity of coal mining, mining conditions have become more complex, and the coal wall spalling and support "crushing" phenomena such as mine pressure on the working face have become more frequent, directly affecting the safe and efficient production of mines. Therefore, studying the characteristics of mine pressure on the working face and effectively predicting its laws are of great significance for guiding coal mine safety production.

[0003] At present, most domestic mining faces have achieved massive and efficient monitoring of support column resistance data, but there is no effective means to conduct in-depth mining and analysis. The traditional analysis method still remains in the manual export of historical data, selecting some supports for simple data analysis, and the determination of end-of-cycle resistance is also mostly done by manual recording, which cannot guarantee data reliability. At the same time, this method has a huge manual workload, poor data analysis results, and does not fully analyze and utilize the massive monitoring data.

[0004] Mechanical research is another approach to mine pressure analysis. After years of theoretical research, various theories such as pressure arch hypothesis, cantilever beam (plate) and masonry beam have been proposed. Mechanical research is mostly based on the force of rock. However, there are unsafe factors in on-site observations, and the different mechanical properties of the overlying rock strata result in the derived mine pressure law only applicable to adjacent working faces or mining areas, and the effect of promotion and application in other domestic coal mine working faces is poor. Summary of the invention

[0005] In view of the above problems, the present invention proposes a method for analyzing periodic pressure on a coal mine working face and a system for analyzing periodic pressure on a coal mine working face.

[0006] An embodiment of the present invention provides a method for analyzing periodic pressure on a coal mine working face, the method comprising:

[0007] Collect the support working resistance of the working surface;

[0008] Extracting the end-cycle resistance of the stent according to the stent working resistance;

[0009] Determine the pressure criterion according to the working resistance of the stent and the end-of-cycle resistance of the stent;

[0010] Based on the pressure judgment criterion, historical data is obtained, and the historical data includes: pressure occurrence cycle, pressure time and pressure step;

[0011] Establishing a pressure forecasting model according to the historical data, wherein the pressure forecasting model is used to predict the pressure step distance and pressure duration of all stents;

[0012] The pressure forecasting model is used to predict the next pressure forecasting area range and pressure step distance.

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

[0014] Collect and obtain the pressure value of a single pillar of the stent;

[0015] Obtaining the support working resistance according to the pressure value of the single support;

[0016] Wherein, the calculation formula of the support working resistance is:

[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, extracting the end-cycle resistance of the stent according to the stent working resistance includes:

[0020] The minimum threshold method is used for the working resistance of the stent, and the resistance change gradient method is combined to process the resistance at the end of the stent cycle is extracted.

[0021] Optionally, the stent working resistance is processed by using a minimum threshold method and combined with a resistance change gradient method to extract the stent end-cycle resistance, including:

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

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

[0024] Select a front working resistance that is less than the minimum working resistance threshold from all support working resistances, and the monitoring time corresponding to the front working resistance is the front monitoring time;

[0025] Based on the sampling interval and the actual support lowering time of the working face, the average support lowering time is calculated;

[0026] Calculate the rear working resistance corresponding to the rear monitoring time, wherein the rear monitoring time is the difference between the front monitoring time and the average lowering time of the support;

[0027] If the difference between the rear working resistance and the front working resistance is greater than the support working resistance difference, the maximum supporting force provided by the support to the top plate before the support is unloaded and lowered is obtained, and the maximum supporting force is the end-of-cycle resistance of the support.

[0028] Optionally, the pressure criterion is determined according to the stent working resistance and the stent end-cycle resistance, including:

[0029] Calculating the sum of the time-weighted working resistance and the mean square error of the support working resistance to obtain a first pressure sub-criterion;

[0030] Calculating the sum of the time-weighted working resistance and the mean square error of the end-cycle resistance of the stent to obtain the second pressure subcriterion;

[0031] The first incoming pressure sub-criterion and the second incoming pressure sub-criterion are combined to form the incoming pressure criterion.

[0032] Optionally, the time-weighted working resistance of the support working resistance is calculated by a curve of the support working resistance and time, and its value is the area enclosed under the curve divided by the total force-bearing time. The area enclosed by the curve is divided into a plurality of small curved-edge trapezoids, and the time-weighted working resistance of the support working resistance is calculated;

[0033] The time-weighted working resistance of the stent end-of-cycle resistance is calculated by a curve of the stent end-of-cycle resistance and time, and its value is the area enclosed by the curve divided by the total force-bearing time. The area enclosed by the curve is divided into a plurality of small curved-edge trapezoids, and the time-weighted working resistance of the stent end-of-cycle resistance is calculated;

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

[0035]

[0036] In the above formula, t1, t2, t n Respectively represent the duration of each small curved trapezoid in the curve corresponding to the working resistance of the stent, or represent the duration of each small curved trapezoid in the curve corresponding to the end-of-cycle resistance of the stent, p0, p1, ... p n They respectively represent the stent working resistance or stent end-cycle resistance corresponding to different monitoring moments;

[0037] The mean square error value σ of the stent working resistance or the stent end-cycle resistance p The calculation formula is:

[0038]

[0039] In the above formula, p0, p1, ... p n They respectively represent the stent working resistance or stent end-cycle resistance corresponding to different monitoring moments;

[0040] The calculation formula of the first pressure criterion or the second pressure criterion is:

[0041]

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

[0043] Optionally, obtaining historical data based on the pressure criterion includes:

[0044] The support working resistance curve and the end-of-cycle resistance curve corresponding to each support are counted. When they reach their respective pressure judgment criteria at the same time, it is determined that the support has cycle pressure, and the historical statistical results of the top plate pressure step distance of the support are obtained. The historical statistical results include: the start time of pressure, the end time of pressure, and the pressure step distance;

[0045] The historical data is obtained according to all historical statistical results.

[0046] Optionally, using the pressure forecasting model to predict the next pressure forecasting area range and pressure step distance includes:

[0047] The pressure forecasting model is used to combine the pressure step length, pressure time and working surface footage information of each support in the most recent period to predict the next pressure start time and pressure step length of each support;

[0048] Count the start time of the next press and the step distance of the next press for all brackets;

[0049] If the difference between the next pressure start time of adjacent brackets is less than a preset value, it is determined to be the same pressure, and the next pressure prediction area range is obtained according to the next pressure start time;

[0050] According to the predicted area range of the next pressure, determine whether the next pressure is a large-cycle pressure or a small-cycle pressure or a local pressure or a pressure on the entire working face;

[0051] The historical pressure step lengths of each bracket are obtained according to the pressure judgment criteria, and statistical analysis is performed on the historical pressure step lengths of each bracket, and the pressure step length with the highest weight is taken as the next pressure step length of each bracket.

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

[0053] Using the pressure forecasting model and combining it with the historical data, the historical pressure start time and pressure step distance of each bracket are obtained;

[0054] Count the historical start time of all brackets and the next step distance of the pressing;

[0055] If the difference between the historical pressure start times of adjacent brackets is less than a preset value, it is determined to be the same pressure, and the historical pressure influence range is obtained according to the historical pressure start time;

[0056] According to the influence range of the historical pressure, determine whether the historical pressure is a large-cycle pressure or a small-cycle pressure or a local pressure or an overall pressure on the working face;

[0057] The historical pressure step lengths of each bracket are counted, and the area with the highest weight is taken as the historical pressure step length of each bracket. The historical minimum cycle pressure step length, the historical maximum pressure duration, and the historical maximum pressure impact range are also counted.

[0058] The embodiment of the present invention provides a system for analyzing periodic pressure on a coal mine working face, and the system for analyzing periodic pressure on a coal mine working face comprises:

[0059] Data acquisition module, used to collect the support working resistance of the working surface;

[0060] An extraction module, used for extracting the end-of-cycle resistance of the stent according to the working resistance of the stent;

[0061] A pressure criterion module, used to determine a pressure criterion according to the working resistance of the support and the end-of-cycle resistance of the support;

[0062] A historical data module, used to obtain historical data based on the pressure judgment criterion, wherein the historical data includes: pressure occurrence cycle, pressure time and pressure step;

[0063] A pressure prediction model module is used to establish a pressure prediction model based on the historical data, and the pressure prediction model is used to predict the pressure step distance and pressure duration of all brackets;

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

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

[0066] Collect and obtain the pressure value of a single pillar of the stent;

[0067] Obtaining the support working resistance according to the pressure value of the single support;

[0068] Wherein, the calculation formula of the support working resistance is:

[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 the resistance change gradient method to extract the end-of-cycle resistance of the stent.

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

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

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

[0076] Select a front working resistance that is less than the minimum working resistance threshold from all support working resistances, and the monitoring time corresponding to the front working resistance is the front monitoring time;

[0077] Based on the sampling interval and the actual support lowering time of the working face, the average support lowering time is calculated;

[0078] Calculate the rear working resistance corresponding to the rear monitoring time, wherein the rear monitoring time is the difference between the front monitoring time and the average lowering time of the support;

[0079] If the difference between the rear working resistance and the front working resistance is greater than the support working resistance difference, the maximum supporting force provided by the support to the top plate before the support is unloaded and lowered is obtained, and the maximum supporting force is the end-of-cycle resistance of the support.

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

[0081] Calculating the sum of the time-weighted working resistance and the mean square error of the support working resistance to obtain a first pressure sub-criterion;

[0082] Calculating the sum of the time-weighted working resistance and the mean square error of the end-cycle resistance of the stent to obtain the second pressure subcriterion;

[0083] Combining the first pressure sub-criterion and the second pressure sub-criterion to form the pressure criterion;

[0084] The time-weighted working resistance of the support working resistance is calculated by a curve of the support working resistance and time, and its value is the area enclosed under the curve divided by the total force-bearing time. The area enclosed by the curve is divided into a plurality of small curved trapezoids, and the time-weighted working resistance of the support working resistance is calculated;

[0085] The time-weighted working resistance of the stent end-of-cycle resistance is calculated by a curve of the stent end-of-cycle resistance and time, and its value is the area enclosed by the curve divided by the total force-bearing time. The area enclosed by the curve is divided into a plurality of small curved-edge trapezoids, and the time-weighted working resistance of the stent end-of-cycle resistance is calculated;

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

[0087]

[0088] In the above formula, t1, t2, t n Respectively represent the duration of each small curved trapezoid in the curve corresponding to the working resistance of the stent, or represent the duration of each small curved trapezoid in the curve corresponding to the end-of-cycle resistance of the stent, p0, p1, ... p n They respectively represent the stent working resistance or stent end-cycle resistance corresponding to different monitoring moments;

[0089] The mean square error value σ of the stent working resistance or the stent end-cycle resistance p The calculation formula is:

[0090]

[0091] In the above formula, p0, p1, ... p n They respectively represent the stent working resistance or stent end-cycle resistance corresponding to different monitoring moments;

[0092] The calculation formula of the first pressure criterion or the second pressure criterion is:

[0093]

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

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

[0096] The support working resistance curve and the end-of-cycle resistance curve corresponding to each support are counted. When they reach their respective pressure judgment criteria at the same time, it is determined that the support has cycle pressure, and the historical statistical results of the top plate pressure step distance of the support are obtained. The historical statistical results include: the start time of pressure, the end time of pressure, and the pressure step distance;

[0097] The historical data is obtained according to all historical statistical results.

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

[0099] The pressure forecasting model is used to combine the pressure step length, pressure time and working surface footage information of each support in the most recent period to predict the next pressure start time and pressure step length of each support;

[0100] Count the start time of the next press and the step distance of the next press for all brackets;

[0101] If the difference between the next pressure start time of adjacent brackets is less than a preset value, it is determined to be the same pressure, and the next pressure prediction area range is obtained according to the next pressure start time;

[0102] According to the predicted area range of the next pressure, determine whether the next pressure is a large-cycle pressure or a small-cycle pressure or a local pressure or a pressure on the entire working face;

[0103] The historical pressure step lengths of each bracket are obtained according to the pressure judgment criteria, and statistical analysis is performed on the historical pressure step lengths of each bracket, and the pressure step length with the highest weight is taken as the next pressure step length of each bracket.

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

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

[0106] Using the pressure forecasting model and combining it with the historical data, the historical pressure start time and pressure step distance of each bracket are obtained;

[0107] Count the historical start time of all brackets and the next step distance of the pressing;

[0108] If the difference between the historical pressure start times of adjacent brackets is less than a preset value, it is determined to be the same pressure, and the historical pressure influence range is obtained according to the historical pressure start time;

[0109] According to the influence range of the historical pressure, determine whether the historical pressure is a large-cycle pressure or a small-cycle pressure or a local pressure or an overall pressure on the working face;

[0110] The historical pressure step lengths of each bracket are counted, and the area with the highest weight is taken as the historical pressure step length of each bracket. The historical minimum cycle pressure step length, the historical maximum pressure duration, and the historical maximum pressure impact range are also counted.

[0111] The method for analyzing periodic pressure on a coal mine working face provided by the present invention first collects the working resistance of the supports on the working face; extracts the support cycle end resistance based on the support working resistance; then determines the pressure criterion based on the support working resistance and the support cycle end resistance; then obtains historical data based on the pressure criterion, and the historical data includes: the occurrence of periodic pressure, the pressure time and the pressure step distance; establishes a pressure prediction model based on the historical data, and the pressure prediction model is used to predict the pressure step distances and pressure durations of all supports; finally, uses the pressure prediction model to predict the next pressure prediction area range and pressure step distance.

[0112] The present invention creatively proposes to use effective means to conduct in-depth mining and analysis of the support column resistance data, which can automatically extract the support cycle end resistance, calculate the support pressure judgment criteria, and extract historical periodic pressure feature information such as pressure step, pressure start time and pressure duration in real time, so as to provide a data sample set for the step prediction model and improve the recognition rate of abnormal mine pressure during the mining process of the working face. By realizing the historical statistical analysis of periodic pressure, the minimum periodic pressure step, maximum pressure duration and maximum pressure impact range of the mining process of the recovery working face can be grasped to provide decision support for the daily production management of the working face and assist in the realization of less-manned or unmanned mining of the working face. To realize the entire method, it is only necessary to connect to the working face support resistance monitoring system to complete the analysis and early warning of periodic pressure. It has good promotion and expansibility in other coal mines and has high practicality. BRIEF DESCRIPTION OF THE DRAWINGS

[0113] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0114] Figure 1 It is a flow chart of a method for analyzing periodic pressure of a coal mining face of a coal machine and a scraper conveyor based on video recognition according to an embodiment of the present invention;

[0115] Figure 2 This is a better control process of the periodic pressure analysis method of the coal mine working face in the embodiment of the present invention;

[0116] Figure 3 It is a block diagram of a periodic pressure analysis system for coal mining machine and scraper conveyor based on video recognition in an embodiment of the present invention. DETAILED DESCRIPTION

[0117] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, are only part of the embodiments of the present invention, not all of the embodiments, and are not used to limit the present invention.

[0118] Reference Figure 1 , shows a flow chart of a method for analyzing periodic pressure on a coal mine working face according to an embodiment of the present invention, the method for analyzing periodic pressure on a coal mine working face comprising:

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

[0120] First, the support working resistance of the working surface needs to be collected. Preferably, the support working resistance should generally be expressed as the pressure of the entire support, while the data collected by the actual monitoring system or equipment is generally the pressure value of a single support column of the support. Therefore, the pressure value of a single support column of the support can be collected first; then the support working resistance can be obtained by calculating the pressure value of the single support column.

[0121] Among them, the calculation formula of the support working resistance is:

[0122]

[0123] In the above formula, P represents the working resistance of the support, the unit is KN, p1 represents the pressure value of the left support, p2 represents the pressure value of the right support, both units are MPa, d represents the inner diameter of a single support, the unit is m.

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

[0125] After the stent working resistance is obtained, the stent end-cycle resistance is extracted based on the stent working resistance. There are many methods for extracting the stent end-cycle resistance, and one of the better methods includes:

[0126] The minimum threshold method is used for the support working resistance, and combined with the resistance change gradient method, the support cycle end resistance is extracted. The so-called support cycle end resistance is the maximum support force provided by the support to the top plate at the end of the load-bearing stage. Specifically:

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

[0128] Based on the sampling interval and the actual support lowering time of the working face, the average support lowering time Δt is calculated; the monitoring time t after calculation before Corresponding rear working resistance p before The so-called post-monitoring time refers to the pre-monitoring time t after The difference between the average bracket lowering time Δt (i.e. t after -Δt=t before ); if the subsequent working resistance p before With the front working resistance p after If the difference between them is greater than the support working resistance difference ΔP, 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 end-of-cycle resistance of the support.

[0129] Combination Figure 2 The figure shows an exemplary end-of-cycle resistance diagram of a support, with the horizontal axis representing time t and the vertical axis representing the support working resistance P, which is divided into five stages: I. initial pressurization stage, II. stable load-bearing stage, III. coal cutting impact stage, IV. adjacent support moving stage, and V. unloading and lowering stage. The figure indicates the minimum working resistance threshold p after the unloading and lowering stage of the support. min , front working resistance p after , front working resistance p after The 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 according to the stent working resistance and the stent end-cycle resistance.

[0131] After obtaining the stent working resistance and the stent end-cycle resistance, the pressure criterion is determined according to the stent working resistance and the stent end-cycle resistance. A preferred method for determining the pressure criterion includes:

[0132] The sum of the time-weighted working resistance and the mean square difference of the support working resistance is calculated to obtain the first pressure sub-criterion; the sum of the time-weighted working resistance and the mean square difference of the support end cycle resistance is calculated to obtain the second pressure sub-criterion; the first pressure sub-criterion and the second pressure sub-criterion are combined to form the pressure criterion.

[0133] Since the time-weighted average resistance is the average working resistance of the bracket calculated with time as the weighting factor, the time-weighted working resistance of the bracket working resistance can be calculated by the Pt curve of the bracket working resistance and time, and its value is the area enclosed under the Pt curve divided by the total force time. For the convenience of calculation, the area enclosed by the Pt curve can be divided into multiple small curved trapezoids (theoretically, the more the better, but the amount of calculation is greater, and the specific number of small curved trapezoids can be determined according to actual needs), so as to calculate the time-weighted working resistance of the bracket working resistance.

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

[0135] Since the calculation formulas for the stent working resistance and the time-weighted working resistance of the stent end-of-cycle resistance are exactly the same, the formulas are not shown repeatedly. You only need to calculate them according to the following formulas. The calculation formula is:

[0136]

[0137] In the above formula, t1, t2, t n They respectively represent the duration of each small curved trapezoid in the curve corresponding to the stent working resistance, or the duration of each small curved trapezoid in the curve corresponding to the stent end cycle resistance, p0, p1, ... p n They respectively represent the stent working resistance or stent end-cycle resistance corresponding to different monitoring moments.

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

[0139]

[0140] In the above formula, p0, p1, ... p n They respectively represent the stent working resistance or stent end-cycle resistance corresponding to different monitoring moments;

[0141] The calculation formula of the first pressure criterion or the second pressure criterion is:

[0142]

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

[0144] Step 104: obtaining historical data based on the pressure judgment criterion, the historical data including: pressure occurrence cycle, pressure time and pressure step.

[0145] After the pressure judgment criteria are obtained, historical data is obtained based on the pressure judgment criteria, and the historical data includes: the pressure occurrence cycle, the pressure time, and the pressure step distance.

[0146] The support working resistance curve and end-of-cycle resistance curve corresponding to each support can be counted. When they reach their respective pressure criteria at the same time, it is determined that the support has undergone periodic pressure. That is, if the support working resistance curve corresponding to any support reaches the first pressure sub-criterion, and the end-of-cycle resistance curve corresponding to the support reaches the second pressure sub-criterion, it is determined that the support has undergone periodic pressure; and as long as one of them is not satisfied, it is considered that the support has not undergone periodic pressure.

[0147] Based on the above method, the historical statistical results of the top plate pressure step distance of the bracket can be obtained, and the 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 (that is, historical statistical results corresponding to all brackets).

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

[0149] After obtaining the historical data, a pressure prediction model can be established based on the historical data. The pressure prediction model is used to predict the pressure step distance and pressure duration of all stents. There are many ways to establish a pressure prediction model, such as using a neural network model, using AI, etc. Naturally, it is understandable that the establishment of a pressure prediction model requires training, calibration, iteration and other processes to ensure the accuracy of the pressure prediction model.

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

[0151] After the pressure forecasting model is established, it can be used to predict the next pressure forecasting area and pressure step.

[0152] By using the pressure prediction model, combined with the pressure step size, pressure time and working face advancement information of each support in the most recent cycle, the next pressure start time and pressure step size of each support are predicted; the next pressure start time and next pressure step size of all supports are counted.

[0153] If the difference in the start time of the next pressure of adjacent brackets is less than the preset value, it is judged as the same pressure, and not as two pressures. Naturally, if the difference in the start time of the next pressure of adjacent brackets is not less than the preset value, it is judged as different pressures. At the same time, the next pressure prediction area range is obtained according to the start time of the next pressure.

[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 surface based on the predicted area range for the next pressure; and obtain the historical pressure step length of each support based on the pressure judgment criterion, and count the historical pressure step lengths of each support, and take the pressure step length with the highest weight as the next pressure step length of each support.

[0155] Through the above steps 101 to 106, the periodic pressure forecast of the coal mining working face can be realized. At the same time, after obtaining the historical data based on the pressure criterion, the historical data is also analyzed:

[0156] The pressure forecasting model is used in combination with historical data to obtain the historical pressure start time and pressure step distance of each bracket; the historical pressure start time and next pressure step distance of all brackets are counted.

[0157] If the difference in the start time of historical pressure of adjacent supports is less than the preset value, it is judged as the same pressure, and the historical pressure influence range is obtained according to the historical pressure start time; according to 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 the entire working face pressure; and the historical pressure step distance of each support is counted, and the area with the highest weight is taken as the historical pressure step distance of each support, and the historical minimum cycle pressure step distance, the historical maximum pressure duration, and the historical maximum pressure influence range are counted. The analysis of historical data is conducive to the expansion of subsequent data sample sets and further improving the accuracy of the pressure prediction model. At the same time, the minimum cycle pressure step distance, the maximum pressure duration, the maximum pressure influence range and other information of the mining process of the mining face are mastered, which also provides decision support for the daily production management of the working face and assists in the realization of less-managed and unmanned mining of the working face.

[0158] In the embodiment of the present invention, based on the above-mentioned coal mine working face periodic pressure analysis method, a coal mine working face periodic pressure analysis system is also proposed, referring to Figure 3 The block diagram of the periodic pressure analysis system of the coal mine recovery working face shown in FIG. 1 includes:

[0159] The data acquisition module 310 is used to collect the support working resistance of the working surface;

[0160] An extraction module 320 is used to extract the end-of-cycle resistance of the stent according to the stent working resistance;

[0161] A pressure criterion module 330, configured to determine a pressure criterion according to the stent working resistance and the stent end-cycle resistance;

[0162] A historical data module 340, for obtaining historical data based on the pressure judgment criterion, wherein the historical data includes: pressure occurrence cycle, pressure time and pressure step;

[0163] A pressure prediction model module 350 is used to establish a pressure prediction model based on the historical data, and the pressure prediction model is used to predict the pressure step distance and pressure duration of all brackets;

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

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

[0166] Collect and obtain the pressure value of a single pillar of the stent;

[0167] Obtaining the support working resistance according to the pressure value of the single support;

[0168] Wherein, the calculation formula of the support working resistance is:

[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 the resistance change gradient method to extract the end-of-cycle resistance of the stent.

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

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

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

[0176] Select a front working resistance that is less than the minimum working resistance threshold from all support working resistances, and the monitoring time corresponding to the front working resistance is the front monitoring time;

[0177] Based on the sampling interval and the actual support lowering time of the working face, the average support lowering time is calculated;

[0178] Calculate the rear working resistance corresponding to the rear monitoring time, wherein the rear monitoring time is the difference between the front monitoring time and the average lowering time of the support;

[0179] If the difference between the rear working resistance and the front working resistance is greater than the support working resistance difference, the maximum supporting force provided by the support to the top plate before the support is unloaded and lowered is obtained, and the maximum supporting force is the end-of-cycle resistance of the support.

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

[0181] Calculating the sum of the time-weighted working resistance and the mean square error of the support working resistance to obtain a first pressure sub-criterion;

[0182] Calculating the sum of the time-weighted working resistance and the mean square error of the end-cycle resistance of the stent to obtain the second pressure subcriterion;

[0183] Combining the first pressure sub-criterion and the second pressure sub-criterion to form the pressure criterion;

[0184] The time-weighted working resistance of the support working resistance is calculated by a curve of the support working resistance and time, and its value is the area enclosed under the curve divided by the total force-bearing time. The area enclosed by the curve is divided into a plurality of small curved trapezoids, and the time-weighted working resistance of the support working resistance is calculated;

[0185] The time-weighted working resistance of the stent end-of-cycle resistance is calculated by a curve of the stent end-of-cycle resistance and time, and its value is the area enclosed by the curve divided by the total force-bearing time. The area enclosed by the curve is divided into a plurality of small curved-edge trapezoids, and the time-weighted working resistance of the stent end-of-cycle resistance is calculated;

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

[0187]

[0188] In the above formula, t1, t2, t n Respectively represent the duration of each small curved trapezoid in the curve corresponding to the working resistance of the stent, or represent the duration of each small curved trapezoid in the curve corresponding to the end-of-cycle resistance of the stent, p0, p1, ... p n They respectively represent the stent working resistance or stent end-cycle resistance corresponding to different monitoring moments;

[0189] The mean square error value σ of the stent working resistance or the stent end-cycle resistance p The calculation formula is:

[0190]

[0191] In the above formula, p0, p1, ... p n They respectively represent the stent working resistance or stent end-cycle resistance corresponding to different monitoring moments;

[0192] The calculation formula of the first pressure criterion or the second pressure criterion is:

[0193]

[0194] In the above formula, P represents the standard value of the first pressure sub-criterion or the second pressure sub-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 support working resistance curve and the end-of-cycle resistance curve corresponding to each support are counted. When they reach their respective pressure judgment criteria at the same time, it is determined that the support has cycle pressure, and the historical statistical results of the top plate pressure step distance of the support are obtained. The historical statistical results include: the start time of pressure, the end time of pressure, and the pressure step distance;

[0197] The historical data is obtained according to all historical statistical results.

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

[0199] The pressure forecasting model is used to combine the pressure step length, pressure time and working surface footage information of each support in the most recent period to predict the next pressure start time and pressure step length of each support;

[0200] Count the start time of the next press and the step distance of the next press for all brackets;

[0201] If the difference between the next pressure start time of adjacent brackets is less than a preset value, it is determined to be the same pressure, and the next pressure prediction area range is obtained according to the next pressure start time;

[0202] According to the predicted area range of the next pressure, determine whether the next pressure is a large-cycle pressure or a small-cycle pressure or a local pressure or a pressure on the entire working face;

[0203] The historical pressure step lengths of each bracket are obtained according to the pressure judgment criteria, and statistical analysis is performed on the historical pressure step lengths of each bracket, and the pressure step length with the highest weight is taken as the next pressure step length of each bracket.

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

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

[0206] Using the pressure forecasting model and combining it with the historical data, the historical pressure start time and pressure step distance of each bracket are obtained;

[0207] Count the historical start time of all brackets and the next step distance of the pressing;

[0208] If the difference between the historical pressure start times of adjacent brackets is less than a preset value, it is determined to be the same pressure, and the historical pressure influence range is obtained according to the historical pressure start time;

[0209] According to the influence range of the historical pressure, determine whether the historical pressure is a large-cycle pressure or a small-cycle pressure or a local pressure or an overall pressure on the working face;

[0210] The historical pressure step lengths of each bracket are counted, and the area with the highest weight is taken as the historical pressure step length of each bracket. The historical minimum cycle pressure step length, the historical maximum pressure duration, and the historical maximum pressure impact range are also counted.

[0211] In summary, the method for analyzing periodic pressure on a coal mine working face provided by the present invention first collects the working resistance of the supports on the working face; extracts the support cycle end resistance based on the support working resistance; then determines the pressure criterion based on the support working resistance and the support cycle end resistance; then obtains historical data based on the pressure criterion, and the historical data includes: the occurrence of periodic pressure, the pressure time and the pressure step distance; establishes a pressure prediction model based on the historical data, and the pressure prediction model is used to predict the pressure step distances and pressure durations of all supports; finally, uses the pressure prediction model to predict the next pressure prediction area range and pressure step distance.

[0212] The present invention creatively proposes to use effective means to conduct in-depth mining and analysis of the support column resistance data, which can automatically extract the support cycle end resistance, calculate the support pressure judgment criteria, and extract historical periodic pressure feature information such as pressure step, pressure start time and pressure duration in real time, so as to provide a data sample set for the step prediction model and improve the recognition rate of abnormal mine pressure during the mining process of the working face. By realizing the historical statistical analysis of periodic pressure, the minimum periodic pressure step, maximum pressure duration and maximum pressure impact range of the mining process of the recovery working face can be grasped to provide decision support for the daily production management of the working face and assist in the realization of less-manned or unmanned mining of the working face. To realize the entire method, it is only necessary to connect to the working face support resistance monitoring system to complete the analysis and early warning of periodic pressure. It has good promotion and expansibility in other coal mines and has high practicality.

[0213] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the embodiments of the present invention.

[0214] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or terminal device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or terminal device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or terminal device including the elements.

[0215] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation modes, which are merely illustrative rather than restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are within the protection of the present invention.

Claims

1. A method for analyzing periodic pressure of a coal mine working face, characterized in that: The method for analyzing periodic pressure on a coal mine working face comprises: Collect the support working resistance of the working surface; Extracting the end-cycle resistance of the stent according to the stent working resistance; Determine the pressure criterion according to the working resistance of the stent and the end-of-cycle resistance of the stent; Based on the pressure judgment criterion, historical data is obtained, and the historical data includes: pressure occurrence cycle, pressure time and pressure step; Establishing a pressure forecasting model according to the historical data, wherein the pressure forecasting model is used to predict the pressure step distance and pressure duration of all stents; The pressure forecasting model is used to predict the next pressure forecasting area range and pressure step distance.

2. The method for analyzing periodic pressure of coal mine working face according to claim 1, characterized in that: Collect the support working resistance of the working surface, including: Collect and obtain the pressure value of a single pillar of the stent; Obtaining the support working resistance according to the pressure value of the single support; Wherein, the calculation formula of the support working resistance is: 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.

3. The method for analyzing periodic pressure of coal mine working face according to claim 1, characterized in that: Extracting the end-cycle resistance of the stent according to the stent working resistance includes: The minimum threshold method is used for the working resistance of the stent, and the resistance change gradient method is combined to process the resistance at the end of the stent cycle is extracted.

4. The method for analyzing periodic pressure of coal mine working face according to claim 3 is characterized in that: The stent working resistance is processed by using the minimum threshold method and combined with the resistance change gradient method to extract the stent end cycle resistance, including: Set the minimum working resistance threshold after the bracket unloading and lowering stage; Set the difference in support working resistance before and after the support unloading and lowering stage; Select a front working resistance that is less than the minimum working resistance threshold from all support working resistances, and the monitoring time corresponding to the front working resistance is the front monitoring time; Based on the sampling interval and the actual support lowering time of the working face, the average support lowering time is calculated; Calculate the rear working resistance corresponding to the rear monitoring time, wherein the rear monitoring time is the difference between the front monitoring time and the average lowering time of the support; If the difference between the rear working resistance and the front working resistance is greater than the support working resistance difference, the maximum supporting force provided by the support to the top plate before the support is unloaded and lowered is obtained, and the maximum supporting force is the end-of-cycle resistance of the support.

5. The method for analyzing periodic pressure of coal mine working face according to claim 1, characterized in that: The pressure criterion is determined according to the stent working resistance and the stent end cycle resistance, including: Calculating the sum of the time-weighted working resistance and the mean square error of the support working resistance to obtain a first pressure sub-criterion; Calculating the sum of the time-weighted working resistance and the mean square error of the end-cycle resistance of the stent to obtain the second pressure subcriterion; The first incoming pressure sub-criterion and the second incoming pressure sub-criterion are combined to form the incoming pressure criterion.

6. The method for analyzing periodic pressure of coal mine working face according to claim 5, characterized in that: The time-weighted working resistance of the support working resistance is calculated by a curve of the support working resistance and time, and its value is the area enclosed by the curve divided by the total force-bearing time. The area enclosed by the curve is divided into a plurality of small curved trapezoids, and the time-weighted working resistance of the support working resistance is calculated; The time-weighted working resistance of the stent end-of-cycle resistance is calculated by a curve of the stent end-of-cycle resistance and time, and its value is the area enclosed by the curve divided by the total force-bearing time. The area enclosed by the curve is divided into a plurality of small curved-edge trapezoids, and the time-weighted working resistance of the stent end-of-cycle resistance is calculated; The stent working resistance or the time-weighted working resistance of the stent end-of-cycle resistance The calculation formula is: In the above formula, t1, t2, t n Respectively represent the duration of each small curved trapezoid in the curve corresponding to the working resistance of the stent, or represent the duration of each small curved trapezoid in the curve corresponding to the end-of-cycle resistance of the stent, p0, p1, ... p n They respectively represent the stent working resistance or stent end-cycle resistance corresponding to different monitoring moments; The mean square error value σ of the stent working resistance or the stent end-cycle resistance p The calculation formula is: In the above formula, p0, p1, ... p n They respectively represent the stent working resistance or stent end-cycle resistance corresponding to different monitoring moments; The calculation formula of the first pressure criterion or the second pressure criterion is: In the above formula, P represents the standard value of the first pressure sub-criterion or the second pressure sub-criterion, m represents the mean coefficient, and n represents the variance coefficient.

7. The method for analyzing periodic pressure of coal mine working face according to claim 1, characterized in that: The historical data is obtained based on the pressure criterion, including: The support working resistance curve and the end-of-cycle resistance curve corresponding to each support are counted. When they reach their respective pressure judgment criteria at the same time, it is determined that the support has cycle pressure, and the historical statistical results of the top plate pressure step distance of the support are obtained. The historical statistical results include: the start time of pressure, the end time of pressure, and the pressure step distance; The historical data is obtained according to all historical statistical results.

8. The method for analyzing periodic pressure of coal mine working face according to claim 1, characterized in that: The pressure forecasting model is used to predict the next pressure forecasting area range and pressure step distance, including: The pressure forecasting model is used to combine the pressure step length, pressure time and working surface footage information of each support in the most recent period to predict the next pressure start time and pressure step length of each support; Count the start time of the next press and the step distance of the next press for all brackets; If the difference between the next pressure start time of adjacent brackets is less than a preset value, it is determined to be the same pressure, and the next pressure prediction area range is obtained according to the next pressure start time; According to the predicted area range of the next pressure, determine whether the next pressure is a large-cycle pressure or a small-cycle pressure or a local pressure or a pressure on the entire working face; The historical pressure step lengths of each bracket are obtained according to the pressure judgment criteria, and statistical analysis is performed on the historical pressure step lengths of each bracket, and the pressure step length with the highest weight is taken as the next pressure step length of each bracket.

9. The method for analyzing periodic pressure of coal mine working face according to claim 1, characterized in that: After obtaining the historical data based on the pressure judgment criterion, the method further includes: Using the pressure forecasting model and combining it with the historical data, the historical pressure start time and pressure step distance of each bracket are obtained; Count the historical start time of all brackets and the next step distance of the pressing; If the difference between the historical pressure start times of adjacent brackets is less than a preset value, it is determined to be the same pressure, and the historical pressure influence range is obtained according to the historical pressure start time; According to the influence range of the historical pressure, determine whether the historical pressure is a large-cycle pressure or a small-cycle pressure or a local pressure or an overall pressure on the working face; The historical pressure step lengths of each bracket are counted, and the area with the highest weight is taken as the historical pressure step length of each bracket. The historical minimum cycle pressure step length, the historical maximum pressure duration, and the historical maximum pressure impact range are also counted.

10. A coal mine working face periodic pressure analysis system, characterized in that: The coal mine working face periodic pressure analysis system comprises: Data acquisition module, used to collect the support working resistance of the working surface; An extraction module, used for extracting the end-of-cycle resistance of the stent according to the working resistance of the stent; A pressure criterion module, used to determine a pressure criterion according to the working resistance of the support and the end-of-cycle resistance of the support; A historical data module, used to obtain historical data based on the pressure judgment criterion, wherein the historical data includes: pressure occurrence cycle, pressure time and pressure step; A pressure prediction model module is used to establish a pressure prediction model based on the historical data, and the pressure prediction model is used to predict the pressure step distance and pressure duration of all brackets; The prediction module is used to use the pressure forecasting model to predict the next pressure forecasting area range and pressure step distance.

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