Statistical method for coal mining cycle based on pressure of hydraulic support column

Abstract

This invention discloses a statistical method for coal mining cycles based on hydraulic support column pressure, belonging to the field of mine pressure analysis and prediction in fully mechanized mining faces. It includes the following steps: S1, screening suspected initial support force and suspected final resistance; S2, determining the number of coal mining cycles; S3, determining the time period of the coal mining cycle; S4, screening coal mining cycles: matching the suspected initial support force and suspected final resistance from step S1 with the time period of the coal mining cycle and the number of coal mining cycles within each time period in step S3 to obtain the number of coal mining cycles for the corresponding production shift. This invention solves the problem of high workload and low accuracy in identifying coal mining cycles from massive amounts of raw mine pressure data in existing technologies. This invention can accurately analyze the initial support force and final resistance from a large amount of support pressure monitoring data, identify coal mining cycles by marking initial support force points and final resistance points, and thus accurately divide the coal mining cycles of the working face, making the analysis and prediction of periodic pressure more efficient and accurate.

Description

Technical Field

[0001] This invention relates to the field of mine pressure analysis and prediction in fully mechanized mining faces, and in particular to a statistical method for coal mining cycles based on the pressure of hydraulic support columns. Background Technology

[0002] During the longwall mining process in a coal mine, as mining operations continue, a large goaf will form behind it. After the roof above the goaf loses the support of the original coal body, the stress balance inside is broken, resulting in a series of complex mechanical behaviors and activities such as bending, subsidence, fracture, and even collapse. This entire process is collectively referred to as mine pressure manifestation.

[0003] Mine pressure manifestation is an objective natural phenomenon that accompanies underground coal mining. However, when the intensity of the mine pressure manifestation exceeds the rated support resistance of the hydraulic supports at the working face or the stability limit of the surrounding rock itself, it can easily induce catastrophic roof collapse accidents. Examples include: large-area roof pressure causing the supports to collapse, rockbursts caused by the sudden fracture of a hard roof, and localized roof falls at the working face, all of which seriously threaten the safety of underground personnel and the stable operation of the production system.

[0004] In recent years, with the continuous increase in coal mining depth and intensity, geological and mining conditions have become increasingly complex. Severe mine pressure manifestations, such as coal face spalling and support collapse, have become more frequent, becoming a key factor restricting safe and efficient mine production. Therefore, effectively predicting the characteristics and patterns of mine pressure manifestations at the working face is of paramount importance for roof disaster prevention and control, support parameter optimization, and production scheduling decisions.

[0005] One of the core prerequisites for achieving accurate mine pressure prediction is to accurately identify each basic coal mining process cycle from the massive amounts of continuously monitored mine pressure data. Currently, the industry generally relies on manual methods to interpret and calculate support pressure data to divide cycles and determine key parameters such as the initial support force and the resistance at the end of the cycle. This method is not only inefficient and labor-intensive, but also highly susceptible to subjective influence from human experience, making it difficult to guarantee consistency and accuracy in identification. It can no longer meet the needs of real-time and automated data processing in the context of intelligent mining.

[0006] Therefore, there is an urgent need to develop a technical method that can automatically and accurately identify the coal mining cycle from the hydraulic support column pressure data, in order to replace the traditional inefficient manual interpretation method and provide a reliable data foundation for coal mine roof safety control and intelligent production decision-making. Summary of the Invention

[0007] The present invention aims to provide a method for statistical analysis of coal mining cycles based on hydraulic support column pressure, which solves the problems of high workload and low accuracy in identifying coal mining cycles from massive amounts of raw mine pressure data in the prior art. It provides a method that can automatically, quickly and accurately identify coal mining cycles and statistically analyze key parameters based on hydraulic support column pressure time series data.

[0008] To achieve the above objectives, the present invention provides the following technical solution: a coal mining cycle statistical method based on hydraulic support column pressure, comprising the following steps: S1, Screening based on suspected initial support and suspected final resistance: Screen out the suspected initial support force and suspected final resistance in the original mine pressure data, and match the suspected initial support force and suspected final resistance one by one; S2. Determine the number of coal mining cycles: The total number of mining cycles experienced by the working face within a day is determined by the working face advance data and the cutting depth of the coal mining machine. S3. Determine the time period of the coal mining cycle: The time period of the production shift is obtained based on the actual production conditions of the working face, and the coal mining cycle of each production shift is calculated. Finally, the time period of the coal mining cycle and the corresponding coal mining cycle within the time period are determined. S4. Coal mining cycle screening: Match the suspected initial support force and suspected final resistance from step S1 with the time period of the coal mining cycle and the number of coal mining cycles in each time period in step S3 to obtain the number of coal mining cycles for the corresponding production shift.

[0009] Furthermore, the specific method for step S1 is as follows: S11. Calculate the slope of the mine pressure curve in chronological order; S12. Determine the suspected final resistance point based on the slope of the mine pressure curve in step S11. S13. Determine the suspected initial support point based on the suspected final resistance point in step S12.

[0010] Furthermore, the method for determining the suspected final resistance point Pm in step S12 is as follows: When the slope of the mine pressure curve Kn > 0, Pn+1 > Pn, that is, the working resistance increases, where P represents the hydraulic support column pressure value and K represents the slope of the curve plotted from the mine pressure data; continue calculating Kn+1, when Kn < 0, Pn+1 < Pn, that is, the working resistance decreases, then A = Pn, C = 1; continue calculating Kn+1, when Kn+1 < 0, and |Kn+1| > k1, that is, the working resistance continues to decrease sharply, where k1 is the judgment... The critical value at which the working resistance drops sharply is determined by the specific production equipment in the mine. Therefore, B = Pn+1, C = 2. Continue calculating Kn+2. When Kn+2 < 0 and |Kn+2| > k1, meaning the working resistance continues to drop sharply, then B = Pn+2, C = 3. When Kn+x > 0 or Kn+x < 0 and |Kn+x| < tan60°, then B = Pn+x-1, C = x+1. If B > 0.5A, then A is not considered Pm, and the calculation begins again. If B < 0.5A, then A is considered Pm.

[0011] Furthermore, the method for determining the suspected initial support point P0 in step S13 is as follows: The calculations in step S12 are continued sequentially according to the time order of the original mine pressure data. When Kn > 0, Pn+1 > Pn, meaning the working resistance increases, and Kn is recorded. Kn+1 is then calculated. When Kn+1 > 0, and |Kn+1| > k2, meaning the working resistance continues to rise, where k2 is the critical value for determining whether the working resistance continues to rise and is determined by the specific production design of the mine. Once a decision is made, record Kn+1; continue calculating Kn+2. When Kn+2 > 0 and |Kn+2| > k2, meaning the working resistance continues to rise, record Kn+2; continue calculating. When |Kn+x-Avg_k| > 0.5×Avg_k, where Avg_k is the average value from Kn to Kn+x-1, and the difference between Pn+x-1 and the initial support force is no more than 20%, Pn+x-1 is considered to be the suspected initial support force point P0.

[0012] Furthermore, the specific method for step S2 is as follows: S21. Determine the daily working face advance and coal mining machine cutting depth: Determine the daily working face advance data of the mine, that is, the coal mining machine advance from 0:00 to 24:00 on a certain day; determine the coal mining machine cutting depth of the working face, that is, the depth to which the coal mining machine drum advances into the coal wall during one cutting process. S22. Calculate the number of coal mining cycles in a day: Using the working face advance data and the cutting depth of the coal mining machine, calculate the total number of coal mining cycles experienced by the working face in a day using the coal mining cycle calculation formula.

[0013] Furthermore, the specific method for step S3 is as follows: S31. Division of production labor time periods at the work face: According to the labor organization at the work face, if it is a 3-8 system, the data of a day is divided into three time periods of 8 hours, namely 0:00-8:00, 8:00-16:00, and 16:00-24:00. If it is a 4-6 system, the data of a day is divided into four time periods of 6 hours, namely 0:00-6:00, 6:00-12:00, 12:00-18:00, and 18:00-24:00. S32. Calculate the time period of the coal mining cycle based on the number of production shifts: Use the working face production labor time period in step S31 to calculate the number of coal mining cycles in each time period.

[0014] Furthermore, the specific method for step S4 is as follows: S41. Considering the oblique cutting and triangular coal cutting process of the coal mining machine, the average coal cutting speed of the coal mining machine is calculated based on the production shift time and the actual operating distance of the coal mining machine as follows: ; In the above formula, It is the average speed of the coal cutting machine. It is the length of the working face. It is the feed distance. It is the number of cycles within the class. It's the production shift time; The formula for calculating the operating time of the coal mining machine during the oblique cutting and triangular coal cutting processes is as follows: ; In the above formula, This refers to the time for advancing the cutting tool and cutting the triangular coal. It is the feed distance. It is the average speed of coal cutting; S42, Mining pressure data from the start of the time period to... The timeframe represents the final resistance of the previous coal mining cycle, with no initial resistance. This means that within the production shift, the initial data for each support is the final resistance. The first initial support force identification point for each support is the time elapsed since the start of the time period. The interval time near the time after the time period The calculation formula is as follows: ; In the above formula, This refers to the work shift duration, where n is the support bracket number. It is the width of the bracket; Found in The initial support force near the specified time, serving as the initial support force for the first cycle of this production shift, corresponds to the final resistance position at... After time △ Near the location, the formula for calculating △T1 is as follows: ; The initial support force of the second cycle is the first initial support force thereafter, and the final resistance of the second cycle increases by Δ after its initial resistance time point. Search around the time, △ The calculation formula is as follows: .

[0015] Compared with existing technologies, the beneficial effects of this solution are: 1. This scheme is based on the slope change of the mine pressure curve. When a continuous and sharp drop in pressure is detected, and the cumulative drop exceeds a set threshold (e.g., 50%), the starting point of this pressure drop is determined as the final resistance point. During the stage where the pressure begins to rise steadily, when a significant change in the resistance slope is detected (e.g., a deviation of more than 50% from the previous average slope), and the current pressure value is close to the designed initial support force, this point is determined as the initial support force point. By using a rigorous slope algorithm and physical process-based criteria to identify feature points, the subjectivity and fatigue errors of manual interpretation are avoided.

[0016] 2. This scheme does not analyze the pressure curve in isolation, but introduces prior knowledge of coal mine production as a constraint. The number of mining cycles is calculated by dividing the daily advance of the working face by the cutting depth of the coal mining machine, providing a target value for the calculation results (i.e., a target value for the statistically derived number of mining cycles). Production shifts are divided according to the mine's labor organization (e.g., 3 / 8 or 4 / 6 system), limiting the search scope to the actual production period. The asymmetry in operating time caused by processes such as oblique cutting and triangular coal cutting by the coal mining machine is considered, and the theoretical time interval from the initial support point to the final resistance point is accurately calculated for different cutting directions. Each accurately defined mining cycle, along with its corresponding initial support force and final resistance values, is the core input data for analyzing the periodic pressure of the working face, studying the roof pressure patterns, and evaluating the working conditions of the hydraulic supports, providing a high-quality data foundation for identifying the initial support force point and final resistance point of the mining cycle.

[0017] 3. This solution enables the identification of coal mining cycles from massive, continuous mine pressure monitoring data, completely changing the inefficient model of relying on manual analysis, calculation, and interpretation of each data point, freeing technical personnel from heavy and repetitive labor. It is a key technological component in realizing an intelligent fully mechanized mining face online mine pressure analysis and prediction system. Its successful application promotes the digitalization and intelligentization of mine pressure management, providing strong technical support for safe, efficient, and intelligent coal mining. Attached Figure Description

[0018] Figure 1 A flowchart of a coal mining cycle statistical method based on hydraulic support column pressure provided by the present invention; Figure 2A flowchart of step S12 of a coal mining cycle statistical method based on hydraulic support column pressure provided by the present invention; Figure 3 A flowchart of step S13 of a coal mining cycle statistical method based on hydraulic support column pressure provided by the present invention; Figure 4 The flowchart of step S4 of the coal mining cycle statistical method based on hydraulic support column pressure provided by the present invention. Detailed Implementation

[0019] The present invention will be further described in detail below through specific embodiments: Related Explanation: This embodiment analyzes the working mine pressure data of a single hydraulic support from massive amounts of mine pressure data, and marks the coal mining cycle by extracting the initial support force and final resistance of the mining cycle. The mine pressure data obtained from underground monitoring comes from pressure sensors installed on designated hydraulic supports at the working face. The mine pressure data monitored by each sensor is relatively independent, while the data monitored by the same sensor changes continuously over time. To make the mine pressure data more comparable, it needs to be grouped according to the increasing or decreasing pattern of the hydraulic support numbers during processing. Since each group corresponds to basically the same equipment operating conditions, it is called a cycle.

[0020] A coal mining cycle refers to the period from the completion of the nth shift of all hydraulic supports to the completion of the (n+1)th shift, which constitutes one coal mining cycle for the working face. For a single hydraulic support, the period from the initial support force loading to the loading of the next initial support force is considered one cycle, called the working cycle of the hydraulic support. In the actual working conditions of the hydraulic support, after the coal mining machine cuts the coal in the current cycle, the hydraulic support undergoes unloading, forward movement, and reloading of the initial support force to start the next cycle. Therefore, for a single hydraulic support, a working cycle consists of the hydraulic support's depressurization, shifting, and loading of the initial support force for the next cycle. During the support operation, the support resistance of the hydraulic support gradually increases over time, reaching its maximum value before the next depressurization and shift. This maximum resistance is the final resistance. At this point, the hydraulic support is depressurized and shifted, and the working resistance decreases sharply. After the shift, once the hydraulic support is in place, an initial support force is first applied; this initial support force is the initial support force. By using the initial support force and the final resistance to determine the key points of the hydraulic support relocation process, the initial support force and the final resistance of the cycle can be accurately analyzed from a large amount of hydraulic support pressure monitoring data, thereby accurately dividing the hydraulic working cycle and the coal mining cycle of the working face.

[0021] like Figure 1 As shown, a statistical method for coal mining cycles based on hydraulic support column pressure includes the following steps: S1. Screening of Suspected Initial Support Force and Suspected Final Resistance: This involves screening out the suspected initial support force and suspected final resistance from the original mine pressure data, and then matching each suspected initial support force with a corresponding suspected final resistance to obtain several sets of suspected initial support forces and suspected final resistances. The specific method is as follows: S11. Calculate the slope Kn of the mine pressure curve in chronological order. Specifically, during the process of "pressure relief, frame shifting, and initial support loading", the mine pressure data obviously went through a process of rapid decline, brief maintenance, and stable rise. This is reflected in the slope of the mine pressure curve as a short-term stable large negative value followed by relative stability near 0.

[0022] The formula for calculating the slope Kn of the mine pressure curve is as follows: .

[0023] Where P represents the hydraulic support column pressure value, and t is the acquisition time corresponding to the mine pressure data point.

[0024] S12. Determine the suspected final resistance point based on the slope of the mine pressure curve in step S11. For example... Figure 2 As shown, the method for determining the suspected final resistance point Pm is as follows: When Kn > 0, Pn+1 > Pn, meaning the working resistance increases, where P represents the hydraulic support column pressure value and K represents the slope of the curve plotted from the mine pressure data; continue calculating Kn+1, when Kn < 0, Pn+1 < Pn, meaning the working resistance decreases, then A = Pn, C = 1; continue calculating Kn+1, when Kn+1 < 0, and |Kn+1| > k1, meaning the working resistance continues to decrease sharply, where k1 is the value used to determine the sharp decrease in working resistance. The critical value for the decrease is determined by the specific production equipment in the mine, so B = Pn+1, C = 2; continue calculating Kn+2. When Kn+2 < 0 and |Kn+2| > k1, that is, the working resistance continues to decrease sharply, then B = Pn+2, C = 3; when Kn+x > 0 or Kn+x < 0 and |Kn+x| < tan60°, then B = Pn+x-1, C = x+1; if B > 0.5A, then A is not considered Pm, and the calculation starts again; if B < 0.5A, then A is considered Pm. The above method completes the identification of the hydraulic support during the pressure relief and relocation process. In the method, whether the working resistance decreases continuously by more than 50% is used as the standard for judging the pressure relief and relocation. At the same time, the parameter k1 is the criterion for judging whether the working resistance of the hydraulic support is in a state of sharp decline. The specific value of k1 is adjusted according to the specific production equipment conditions of the specific mine.

[0025] S13. Determine the suspected initial support point based on the suspected final resistance point in step S12. For example... Figure 3As shown, the method for determining the suspected initial support point P0 is as follows: The calculation in step S12 is performed sequentially according to the time order of the original mine pressure data. When Kn > 0, Pn+1 > Pn, meaning the working resistance increases, and Kn is recorded. Kn+1 is then calculated. When Kn+1 > 0, and |Kn+1| > k2, meaning the working resistance continues to rise, where k2 is the critical value for determining whether the working resistance continues to rise and is determined by the specific production equipment in the mine. Kn+1 is recorded. The calculation continues... Calculate Kn+2. When Kn+2 > 0 and |Kn+2| > k2, the working resistance continues to rise, and Kn+2 is recorded. At this point, the mine pressure data shows a relatively stable upward phase. Calculations continue. When |Kn+x-Avg_k| > 0.5×Avg_k, where Avg_k is the average value from Kn to Kn+x-1, and Pn+x-1 differs from the designed initial support force by no more than 20%, then Pn+x-1 is considered the suspected initial support force point P0. The principle is as follows: Since the mine pressure data mainly increases from the initial support force loading stage, the slope of the resistance increase differs between the initial support force setting stage and the resistance increase stage under the influence of mine pressure. It is generally believed that the resistance increase slope is relatively stable during the initial support force resistance increase period, so this characteristic is used as the basis for judging the initial resistance P0. Specifically, when the slope of the increase in mine pressure data changes by 50% compared to the average of the previous increases, and the difference from the initial design support force is less than 20%, the initial resistance P is considered to have been reached. These two thresholds, 50% and 20%, are empirical standards developed through long-term practice, data accumulation, and theoretical analysis in the mining engineering field, and are widely used in the industry. As a universal criterion, they effectively balance the timeliness, safety, and reliability of detection. Meanwhile, parameter k2 is a criterion for judging whether the working resistance curve of the hydraulic support is in a relatively stable upward state; the specific value of k2 is adjusted according to the specific production equipment conditions of the specific mine.

[0026] S2. Determine the number of mining cycles: Based on the face advance data and the cutting depth of the coal mining machine, determine the total number of mining cycles experienced by the face within the day. The specific method is as follows: S21. Determine the daily working face advance and coal mining machine cutting depth: Determine the daily working face advance data for the mine, i.e., the depth of the coal mining machine advance from 0:00 to 24:00 on a given day. The working face advance depth is important data for determining the number of daily coal mining cycles. Determine the coal mining machine cutting depth, i.e., the depth to which the coal mining machine drum advances into the coal wall during one cutting operation. The coal mining machine cutting depth is a necessary parameter for calculating the number of daily coal mining cycles.

[0027] S22. Calculate the number of coal mining cycles per day: Using the face advance data and the cutting depth of the coal mining machine, calculate the total number of coal mining cycles experienced by the face within the day using the coal mining cycle calculation formula. This serves as the target value for the number of initial support force and final resistance identifications; that is, the subsequent number of initial support force and final resistance identifications must correspond to the number of coal mining cycles. The formula for calculating the number of coal mining cycles per day is as follows: ; The number of cycles per day is Daily progress is The cutting depth of the coal mining machine is If the number of coal mining cycles calculated in this step is not an integer, it is rounded up.

[0028] S3. Determine the time period of the coal mining cycle: Based on the actual production conditions of the working face, obtain the time period of the production shift and calculate the number of coal mining cycles for each production shift. Finally, determine the time periods in which coal mining cycles exist and the coal mining cycles within each time period. The specific method is as follows: S31. Division of working face production labor time periods: According to the working face labor organization, if it is a 3-8 system, the daily data is divided into three time periods of 8 hours, namely 0:00-8:00, 8:00-16:00, and 16:00-24:00; if it is a 4-6 system, the daily data is divided into four time periods of 6 hours, namely 0:00-6:00, 6:00-12:00, 12:00-18:00, and 18:00-24:00.

[0029] S32. Calculate the time period of the coal mining cycle based on the number of production shifts: Use the working face production labor time period from step S31 to calculate the number of coal mining cycles within each time period. A production shift refers to the shift responsible for operating the coal mining machine to cut coal during a day's coal mining work. The number of production shifts and their time periods vary from mine to mine. The division is based on the actual production shift time of different mines. Many mines do not strictly adhere to the cycle operation chart during actual production, but the coal cutting progress of each coal mining shift is relatively stable. In this case, it is necessary to obtain the time period of the production shift based on the actual production conditions of the working face. The formula for calculating the number of coal mining cycles in each time period is as follows: ; The number of coal mining cycles within the time period is: Number of production shifts .

[0030] S4. Screening of Coal Mining Cycles: Match the suspected initial support force and suspected final resistance from step S1 with the time period and number of coal mining cycles in step S3 to obtain the number of coal mining cycles for the corresponding production shift. The specific method is as follows: S41. Basic Parameter Calculation: During the screening process, it is necessary to calculate the time interval between the initial support force and the final resistance. Therefore, it is necessary to consider the oblique cutting advance of the coal mining machine and the process of cutting triangular coal. Based on the production shift time and the actual running distance of the coal mining machine, the average coal cutting speed of the coal mining machine is calculated as follows: ; In the above formula, It is the average speed of the coal cutting machine. It is the length of the working face. It is the feed distance. It is the number of cycles within the class. It's production shift time.

[0031] The formula for calculating the operating time of the coal mining machine during the oblique cutting and triangular coal cutting processes is as follows: ; In the above formula, This refers to the time for advancing the cutting tool and cutting the triangular coal. It is the feed distance. It is the average speed of coal cutting.

[0032] S42. Calculation of the interval between initial support force and final resistance: Due to the different coal cutting directions of the coal mining machine, the time span between the initial support force and the final resistance is also different, but there is a symmetrical relationship. The mine pressure data from the start of the time period to time T1 represents the final resistance of the previous coal mining cycle, with no initial resistance. That is, within the production shift, the initial data of the hydraulic support is the final resistance. The first initial support force identification point for each hydraulic support is near the time after the start of the time period T1. The formula for calculating the interval T1 is as follows: ; In the above formula, This refers to the work shift duration, where n is the support bracket number. It refers to the width of the bracket.

[0033] Following the method described above, find in The initial support force near the specified time is taken as the initial support force for the first cycle of this production shift. The corresponding final resistance position is then... After time △ Near the location, △ The calculation formula is as follows: ; The aforementioned final resistance is the final resistance of the first coal mining cycle in this production shift. The initial support force of the second cycle is the first initial support force thereafter. The final resistance of the second cycle increases by Δ after its initial resistance time point. Search around the time, △ The calculation formula is as follows: .

[0034] Using the above method, the initial support point and the final resistance point of the coal mining cycle can be found in the suspected initial support point and the suspected final resistance point.

[0035] The technical principle of this solution is as follows: First, valid data for a specific hydraulic support on the working face needs to be extracted. Valid data refers to the hydraulic support pressure data for a particular hydraulic support during a specific production shift on a specific day. The valid data includes suspected initial support force points and suspected final resistance points obtained through step S1. The valid data is then matched with the coal mining cycle for data processing. Coal mining cycle matching requires the number of coal mining cycles in the production shift; here, we assume the number of coal mining cycles in the production shift is X. The flowchart for coal mining cycle matching is as follows: Figure 4 As shown, the process begins by identifying the start time of a time period. The period from this start time to time T1 represents the final resistance of the previous coal mining cycle. Near the end of time T1 after the start time, the first initial support force identification point of the hydraulic support in this production shift can be obtained. The corresponding final resistance position is then found near the position ΔT1 after time T1. The found final resistance is the final resistance of the first coal mining cycle in this production shift. The initial support force of the second cycle is the first initial resistance thereafter. Therefore, the initial support force of the second cycle is found near the end of time T1 after the first coal mining cycle's final resistance point found above. The final resistance of the second cycle is found near the end of time ΔT2 after the initial resistance point. Thus, the final resistance point is found alternately in ΔT1 and ΔT2 cycles, while the initial support force point is found in T1, thereby obtaining the initial support force point and final resistance point of the coal mining cycle.

[0036] As described in steps S41-S42 above, the goal is to select the final initial support point and final resistance point by referring to the suspected initial support point and suspected final resistance point determined in S1 and the number of coal mining cycles determined in S3 for each time period. Then, the initial support point and final resistance point corresponding to the number of coal mining cycles in this production shift are arranged in chronological order in the original mine pressure data to identify each coal mining cycle of the production shift.

[0037] The above are merely embodiments of the present invention, and common knowledge such as specific structures and / or characteristics in the solutions are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the structure of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A coal mining cycle statistical method based on hydraulic support stand column pressure, characterized in that: Includes the following steps: S1, Screening based on suspected initial support and suspected final resistance: Screen out the suspected initial support force and suspected final resistance in the original mine pressure data, and match the suspected initial support force and suspected final resistance one by one; S2. Determine the number of coal mining cycles: The total number of mining cycles experienced by the working face within a day is determined by the working face advance data and the cutting depth of the coal mining machine. S3. Determine the time period of the coal mining cycle: The time period of the production shift is obtained based on the actual production conditions of the working face, and the coal mining cycle of each production shift is calculated. Finally, the time period of the coal mining cycle and the corresponding coal mining cycle within the time period are determined. S4. Coal mining cycle screening: Match the suspected initial support force and suspected final resistance from step S1 with the time period of the coal mining cycle and the number of coal mining cycles in each time period in step S3 to obtain the number of coal mining cycles for the corresponding production shift.

2. The coal mining cycle statistics method based on the pressure of hydraulic support columns according to claim 1, characterized in that, The specific method for step S1 is as follows: S11. Calculate the slope of the mine pressure curve in chronological order; S12. Determine the suspected final resistance point based on the slope of the mine pressure curve in step S11. S13. Determine the suspected initial support point based on the suspected final resistance point in step S12.

3. The coal mining cycle statistics method based on the hydraulic support column pressure according to claim 2, characterized in that, The method for determining the suspected final resistance point Pm in step S12 is as follows: When the slope of the mine pressure curve Kn > 0, Pn+1 > Pn, that is, the working resistance increases, where P represents the pressure value of the hydraulic support column and K represents the slope of the curve plotted from the mine pressure data; continue calculating Kn+1, when Kn < 0, Pn+1 < Pn, that is, the working resistance decreases, then A = Pn, C = 1; continue calculating Kn+1, when Kn+1 < 0, and |Kn+1| > k1, that is, the working resistance continues to decrease sharply, where k1 is the threshold for judging the working resistance. The critical value at which the resistance drops sharply is determined by the specific production equipment in the mine, so B = Pn+1, C = 2; continue calculating Kn+2. When Kn+2 < 0 and |Kn+2| > k1, that is, the working resistance continues to drop sharply, then B = Pn+2, C = 3; when Kn+x > 0 or Kn+x < 0 and |Kn+x| < tan60°, then B = Pn+x-1, C = x+1; if B > 0.5A, then A is not considered Pm, and the calculation starts again; if B < 0.5A, then A is considered Pm.

4. The coal mining cycle statistics method based on the pressure of hydraulic support columns according to claim 3, characterized in that, The method for determining the suspected initial support point P0 in step S13 is as follows: Continue the calculation from step S12 according to the time sequence of the original mine pressure data. When Kn > 0, Pn+1 > Pn, meaning the working resistance increases, and record Kn. Continue calculating Kn+1. When Kn+1 > 0, and |Kn+1| > k2, meaning the working resistance continues to rise, where k2 is the critical value for determining whether the working resistance continues to rise and is determined by the specific production equipment in the mine. Set Kn+1 and record it. Continue calculating Kn+2. When Kn+2 > 0 and |Kn+2| > k2, that is, the working resistance continues to rise, record Kn+2. Continue the calculation. When |Kn+x-Avg_k| > 0.5×Avg_k, where Avg_k is the average value from Kn to Kn+x-1, and the difference between Pn+x-1 and the design initial support force is not greater than 20%, Pn+x-1 is considered to be the suspected initial support force point P0.

5. The coal mining cycle statistics method based on the hydraulic support column pressure according to claim 1, characterized in that, The specific method for step S2 is as follows: S21. Determine the daily working face advance and coal mining machine cutting depth: Determine the daily working face advance data of the mine, that is, the coal mining machine advance from 0:00 to 24:00 on a certain day; determine the coal mining machine cutting depth of the working face, that is, the depth to which the coal mining machine drum advances into the coal wall during one cutting process. S22. Calculate the number of coal mining cycles in a day: Using the working face advance data and the cutting depth of the coal mining machine, calculate the total number of coal mining cycles experienced by the working face in a day using the coal mining cycle calculation formula.

6. The coal mining cycle statistics method based on the pressure of hydraulic support columns according to claim 1, characterized in that, The specific method for step S3 is as follows: S31. Division of production labor time periods at the work face: According to the labor organization at the work face, if it is a 3-8 system, the data of a day is divided into three time periods of 8 hours, namely 0:00-8:00, 8:00-16:00, and 16:00-24:

00. If it is a 4-6 system, the data of a day is divided into four time periods of 6 hours, namely 0:00-6:00, 6:00-12:00, 12:00-18:00, and 18:00-24:

00. S32. Calculate the time period of the coal mining cycle based on the number of production shifts: Use the working face production labor time period in step S31 to calculate the number of coal mining cycles in each time period.

7. The coal mining cycle statistics method based on the pressure of hydraulic support columns according to claim 6, characterized in that, The specific method for step S4 is as follows: S41. Considering the oblique cutting and triangular coal cutting process of the coal mining machine, the average coal cutting speed of the coal mining machine is calculated based on the production shift time and the actual operating distance of the coal mining machine as follows: ； in the above formula, is the average coal cutting speed of the coal cutter, is the length of the working face, is the feed distance, is the number of cycles within a shift, is the production shift time; The formula for calculating the operating time of the coal mining machine during the oblique cutting and triangular coal cutting processes is as follows: ； In the above formula, This refers to the time for advancing the cutting tool and cutting the triangular coal. It is the feed distance. It is the average speed of coal cutting; S42, Mining pressure data from the start of the time period to... The timeframe represents the final resistance of the previous coal mining cycle, with no initial resistance. This means that within the production shift, the initial data for each support is the final resistance. The first initial support force identification point for each support is the time elapsed since the start of the time period. The interval time near the time after the time period The calculation formula is as follows: ； In the above formula, This refers to the work shift duration, where n is the support bracket number. It is the width of the bracket; Found in The initial support force near the specified time is used as the initial support force for the first cycle of this production shift, and the corresponding final resistance position is at... After time △ Near the location, the formula for calculating △T1 is as follows: ； The initial support force of the second cycle is the first initial support force thereafter, and the final resistance of the second cycle increases by Δ after its initial resistance time point. Search around the time, △ The calculation formula is as follows: 。

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