A method for controlling coal caving by coordinated feedback of pressure and vibration information in fully mechanized caving mining

Abstract

The present invention relates to the field of automatic control technology for top coal caving, and specifically to a method for controlling coal caving using pressure-vibration information coordinated feedback in fully mechanized caving. The method first acquires real-time pressure and vibration data, and then, based on the functional relationship between the bearing pressure of the support shield beam and the top coal discharge volume, and a relationship model between the gangue content of the top coal discharged from the caving port and the impact vibration response law of the support tail beam and rear scraper conveyor, obtains the real-time top coal discharge volume and the gangue content of the top coal discharged from the caving port, and calculates the mass proportion of gangue in the total discharged coal gangue body. When the mass proportion of gangue in the total discharged coal gangue body exceeds one-fifth, the caving port is automatically closed to stop coal caving. The present invention can solve the problems of low manual coal gangue identification accuracy caused by harsh environments such as high coal dust, poor lighting, and high noise in fully mechanized caving faces, as well as inaccurate caving port switch control due to excessive local instantaneous gangue content. It keeps workers away from the hydraulic support operating area, ensuring their production safety and reducing their labor intensity.

Description

Technical Field

[0001] The present invention relates to the technical field of automatic control of top coal caving, and in particular to a method for controlling coal caving through coordinated feedback of pressure and vibration information in fully-mechanized top coal caving. Background Art

[0002] Fully-mechanized top-coal caving (FCC) is one of the primary mining methods for thick coal seams. Gangue identification is a core technology in FCC mining and a key enabler for intelligent mining. In recent years, gangue identification technology has developed rapidly. Infrared and vibration technologies hold the greatest promise for gangue identification, with vibration technology being the most practical and feasible. However, the variety of vibration signals present in fully-mechanized top-coal caving faces, including those from mechanical noise and human activity, overlaps in their signal spectra, making it difficult for the resulting signal to directly reflect the gangue content. This significantly limits the accuracy of single vibration signal identification. Furthermore, the inability to determine the mass ratio of coal to gangue in the total top-coal discharge results in the caving port opening being partially dependent on the instantaneous gangue content, resulting in poor caving performance and low production efficiency. Therefore, a method for controlling coal caving in FCC mining using coordinated feedback from pressure and vibration information is proposed. This method is of great significance for improving the accuracy of gangue identification and advancing the intelligent development of top-coal caving, and represents an urgent challenge for those skilled in the art.

[0003] It should be noted that the information disclosed in the background technology section of the present invention is only intended to increase the understanding of the overall background of the present invention, and should not be regarded as an admission or any form of implication that the information constitutes prior art already known to those skilled in the art. Summary of the Invention

[0004] In view of the above-mentioned deficiencies in the prior art, the present invention provides a method for controlling coal caving by using pressure-vibration information coordinated feedback in fully-mechanized caving mining to achieve precise automatic control of the caving port switch, comprising the following steps:

[0005] S1: Install a pressure sensor on the support shield beam, a laser scanning device on the rear scraper conveyor, and a vibration sensor on the support tail beam and the rear scraper conveyor;

[0006] S2: using a pressure sensor to collect pressure signals to obtain bearing pressure data of the support shield beam, using a laser scanning device to obtain top coal caving amount data, and using a vibration sensor to obtain vibration signals to obtain vibration data; the top coal is a coal gangue body mixed with gangue;

[0007] S3: Establish the functional relationship between the bearing pressure of the support shield beam and the amount of top coal released;

[0008] S4: Establish a model for the relationship between the gangue content of the top coal discharged from the coal caving port and the impact vibration response of the support tail beam and rear scraper conveyor;

[0009] S5: Integrate the time series characteristics of the pressure and vibration signals to obtain the real-time mass ratio of gangue in the total discharged coal gangue, and realize automatic control of the coal discharge port switch based on the coal discharge closing conditions.

[0010] Preferably, in step S3, several sets of support shield beam bearing pressure data and corresponding top coal discharge amount data are recorded; and a function equation of the support shield beam bearing pressure and top coal discharge amount is obtained by software fitting.

[0011] Preferably, in step S4, a physical simulation method is used to obtain experimental data, and then a relationship model between the gangue content of the top coal discharged from the coal discharge port and the impact vibration response law of the support tail beam and the rear scraper conveyor is established based on a neural network.

[0012] Preferably, in step S5, real-time support shielding beam bearing pressure data is obtained based on the pressure sensor and the vibration sensor, and real-time vibration data is obtained by obtaining the vibration signal; based on the relationship model between the gangue content of the top coal discharged from the coal discharge port and the impact vibration response law of the support tail beam and the rear scraper conveyor, the real-time gangue content of the top coal discharged from the coal discharge port is predicted; the relationship between the support shielding beam bearing pressure data and time is substituted into the functional relationship between the support shielding beam bearing pressure and the top coal discharge amount to obtain the real-time top coal discharge amount; based on the real-time gangue content of the top coal discharged from the coal discharge port and the real-time top coal discharge amount, the mass proportion of gangue in the total discharged coal gangue body is calculated.

[0013] Preferably, in step S5, the closing condition of the coal discharge port is: the mass proportion of gangue in the total discharged coal gangue exceeds one-fifth.

[0014] Preferably, in steps S2 and S5, the obtained vibration signal is subjected to denoising processing to obtain vibration data.

[0015] From the technical solution of the above-mentioned method for coordinated feedback control of coal discharge by pressure-vibration information in fully mechanized top-coal caving mining, it can be seen that: the present invention proposes to monitor the bearing pressure of the support shield beam, the impact vibration of the support tail beam and the rear scraper conveyor during the coal discharge process, and establish a functional relationship between the bearing pressure of the support shield beam and the amount of top coal discharged, and a relationship model of the response law of the gangue content in the coal discharge port and the impact vibration of the support tail beam and the rear scraper, the mass proportion of gangue in the total discharge body at any time is obtained, and the opening and closing of the coal discharge port are automatically controlled according to the coal discharge port closing criteria.

[0016] The present invention can solve the problems of low accuracy in manual identification of coal gangue caused by harsh environments such as high coal dust, poor lighting, and high noise in the fully-mechanized caving face, and inaccurate control of the coal port switch due to excessive local instantaneous gangue content. It keeps workers away from the hydraulic support operation area, ensures workers' production safety, and reduces their labor intensity. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the following detailed description, they are used to explain the present invention but do not constitute a limitation of the present invention. In the accompanying drawings:

[0018] Figure 1 This is a flow chart of the method for controlling coal caving by coordinated feedback of pressure and vibration information in fully-mechanized caving mining according to the present invention;

[0019] Figure 2 This is a flow chart of the vibration signal denoising process described in the present invention. DETAILED DESCRIPTION

[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0021] like Figure 1 As shown, the present invention proposes a method for controlling coal caving by using pressure-vibration information coordinated feedback in fully-mechanized caving mining, comprising the following steps:

[0022] S101: Install a pressure sensor on the support shield beam, a laser scanning device on the rear scraper conveyor, and a vibration sensor on the support tail beam and the rear scraper conveyor;

[0023] The step S101 specifically includes:

[0024] S1011: Install the pressure sensor at the geometric center of the inner side of the support shield beam;

[0025] S1012: Install the laser scanning device on the upper part of the rear scraper conveyor;

[0026] S1013: Install vibration sensors on the inner side of the support tail beam and the inner side of the rear scraper conveyor. The vibration sensors are provided with metal protective shells to prevent damage caused by the impact of coal gangue flow during coal placement.

[0027] S102: using a pressure sensor to collect pressure signals to obtain bearing pressure data of the support shield beam, using a laser scanning device to obtain top coal caving amount data, and using a vibration sensor to obtain vibration signals and perform denoising processing to obtain vibration data; the top coal is coal gangue mixed with gangue;

[0028] like Figure 2 As shown, in step S102, the step of obtaining a vibration signal by using a vibration sensor and performing denoising processing to obtain vibration data specifically includes:

[0029] S1021: Obtain the initial vibration signal and perform denoising using the underdetermined denoising source separation method of quadratic variable differential mode (QVMD) and principal component analysis (PCA);

[0030] S1022: Input an initial vibration signal, set the hidden layer parameters to their maximum values, perform VMD decomposition on the initial vibration signal, derive two-dimensional intrinsic mode function components, use whether the layer number parameter is the initial value or the optimal value as a judgment criterion, feed the initial value back into the calculation, decompose the eigenvalues ​​by solving the autocorrelation coefficient, normalize and arrange the eigenroots and calculate the gradient, modify the layer number parameter to the optimal value, perform quadratic signal decomposition (QVMD), perform principal component source signal statistics on the optimal value that meets the conditions, separate the denoised vibration signal, and obtain denoised vibration data;

[0031] S103: establishing a functional relationship between the bearing pressure of the support shield beam and the amount of top coal released;

[0032] The step S103 specifically includes:

[0033] S1031: The bearing pressure data of the support shield beam is directly obtained by the pressure sensor, and the top coal discharge volume data is obtained by measuring the amount of coal piled on the scraper conveyor by the laser scanning device;

[0034] S1032: Recording the bearing pressure data and corresponding top coal discharge amount data of 50 groups of support shield beams within a coal caving step;

[0035] S1033: Use software fitting to obtain the function equation of the support shield beam bearing pressure and the top coal discharge amount, select different fitting function equation forms, and select the function equation that satisfies the correlation coefficient R. 2 The maximum correlation coefficient among the fitting function equations with a value greater than 0.95 is selected as the functional relationship between the support shield beam bearing pressure and the top coal discharge amount, f(x), where x is the support shield beam bearing pressure, in MPa, and f(x) is the top coal discharge amount, in t.

[0036] S104: Establish a model for the relationship between the gangue content of the top coal discharged from the coal caving port and the impact vibration response of the support tail beam and rear scraper conveyor;

[0037] The step S104 specifically includes:

[0038] S1041: Use the same metal plate as the support tail beam to build a support tail beam simulation platform with the same working inclination angle as the support tail beam, and use the same material as the rear scraper conveyor to build a rear scraper conveyor simulation platform;

[0039] S1042: Install vibration sensors on the bracket tail beam simulation platform and the rear scraper conveyor simulation platform;

[0040] S1043: Conduct impact vibration simulation using coal gangue with simulated gangue contents of 0%, 5%, 10%, 15%, 20%, 25%, and 30%. The calculation formula for the simulated gangue contents is as follows:

[0041]

[0042] Where: n simulation is the simulated gangue content, unit: %; m gangue is the mass of gangue in coal gangue, unit is kg, m coal is the mass of coal in the coal gangue, unit: kg;

[0043] S1044: extracting the characteristic vector of the vibration signal after denoising at different simulated gangue content rates; wherein, the denoising method of the vibration signal refers to steps S1021-S1022;

[0044] S1045: dividing the denoised vibration signal's feature vector and the simulated gangue content into a training data set and a test data set, and importing them into a neural network;

[0045] S1046: Define the number of training times, the number of nodes in each hidden layer, the number of hidden layers, the learning rate, set the type of activation function, and build a neural network for training and prediction;

[0046] S1047: Compare the errors between the true and predicted values ​​of the test data set. If the total error is less than 5%, the model is considered to be able to predict the gangue content. A neural network-based relationship model is obtained between the gangue content of the top coal discharged from the caving port and the impact vibration response of the support tail beam and rear scraper conveyor.

[0047] S105: Integrate the time series characteristics of the pressure and vibration signals to obtain the real-time mass ratio of gangue in the total discharged coal gangue, and realize automatic control of the coal discharge port switch based on the coal discharge closing conditions;

[0048] The step S105 specifically includes:

[0049] S1051: Acquire real-time support shield beam bearing pressure data and vibration signals based on the pressure sensor and vibration sensor, respectively, and perform denoising on the vibration signals to obtain vibration data; the denoising method is similar to steps S1021-S1022;

[0050] S1052: Based on the relationship model between the gangue content of the top coal discharged from the coal caving port and the impact vibration response law of the support tail beam and rear scraper conveyor, the real-time gangue content n of the top coal discharged from the coal caving port is predicted. real ;

[0051] Substitute the relationship between the support shield beam bearing pressure data and time g(t), that is, the support shield beam bearing pressure data corresponding to any time during the top coal discharge process, into the functional relationship between the support shield beam bearing pressure and the top coal discharge amount, and obtain the functional equation f(g(t)) between the top coal discharge amount and time, that is, the real-time top coal discharge amount;

[0052] S1053: Calculate the mass ratio of gangue in the total discharged coal gangue based on the real-time gangue content of the top coal discharged from the coal caving port and the real-time top coal discharged amount; the calculation formula for the mass ratio of gangue in the total discharged coal gangue is as follows:

[0053]

[0054] Where: t is time, unit is s; n totle is the mass proportion of gangue in the total discharged volume; n real is the gangue content of the coal gangue flow at the coal outlet, g(t) is the relationship between pressure and time;

[0055] S1054: The closing condition of the coal discharge port is: when the mass proportion of gangue in the total discharged coal gangue exceeds one-fifth, the coal discharge port is closed and coal discharge is stopped.

[0056] The present invention can realize the coordinated feedback control of pressure signal and vibration signal to control coal discharge, and at the same time avoid the problem of stopping coal discharge due to excessive instantaneous gangue content, which causes low coal discharge efficiency. The pressure signal data and vibration signal data at any time are obtained through sensors. Based on the functional relationship between the bearing pressure of the support shielding beam and the top coal discharge amount, and the relationship model between the gangue content of the top coal discharged from the coal discharge port and the impact vibration response law of the support tail beam and the rear scraper conveyor, the real-time top coal discharge amount and the gangue content of the top coal discharged from the coal discharge port are obtained. According to the real-time gangue content of the top coal discharged from the coal discharge port and the real-time top coal discharge amount, the mass proportion of gangue in the total discharged coal gangue body is calculated. When the mass proportion of gangue in the total discharged body exceeds one-fifth, the coal discharge port is automatically closed to stop coal discharge.

[0057] The above description of the disclosed embodiments is presented in an incremental manner to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is to be construed in the widest possible manner consistent with the principles and novel features disclosed herein.

Claims

1. A method for controlling coal caving by using pressure-vibration information coordinated feedback in fully mechanized caving mining, characterized in that: The following steps are involved: S1: Install a pressure sensor on the support shield beam, a laser scanning device on the rear scraper conveyor, and a vibration sensor on the support tail beam and the rear scraper conveyor; S2: Using a pressure sensor to collect pressure signals to obtain bearing pressure data of the support shield beam, using a laser scanning device to measure the amount of coal piled on the rear scraper conveyor to obtain top coal discharge data, and using a vibration sensor to obtain vibration signals to obtain vibration data; the top coal is coal gangue mixed with gangue; S3: Establish the functional relationship between the bearing pressure of the support shield beam and the amount of top coal released; S4: Use physical simulation methods to obtain experimental data, and then establish a relationship model between the gangue content of the top coal discharged from the coal caving port and the vibration signals of the support tail beam and rear scraper conveyor based on a neural network; S5: Integrate the time series characteristics of the pressure and vibration signals to obtain the real-time mass ratio of gangue in the total discharged coal gangue, and realize automatic control of the coal discharge port switch based on the coal discharge closing conditions; Real-time support shielding beam bearing pressure data and vibration signal are obtained based on pressure sensor and vibration sensor respectively; based on the relationship model between the gangue content of top coal discharged from the coal discharge port and the vibration signal of the support tail beam and rear scraper conveyor, the real-time gangue content of the top coal discharged from the coal discharge port is predicted; the relationship between the support shielding beam bearing pressure data and time is substituted into the functional relationship between the support shielding beam bearing pressure and the top coal discharge amount to obtain the real-time top coal discharge amount; based on the real-time gangue content of the top coal discharged from the coal discharge port and the real-time top coal discharge amount, the mass proportion of gangue in the total discharged coal gangue is calculated.

2. The method for controlling coal caving by using pressure-vibration information coordinated feedback in fully-mechanized caving mining according to claim 1 is characterized in that: In steps S2 and S5, the obtained vibration signal is subjected to denoising processing to obtain vibration data.

3. The method for controlling coal caving by using pressure-vibration information coordinated feedback in fully-mechanized caving mining according to claim 1 is characterized in that: In step S3, several sets of support shield beam bearing pressure data and corresponding top coal discharge amount data are recorded; and a function equation of the support shield beam bearing pressure and the top coal discharge amount is obtained by software fitting.

4. The method for controlling coal caving by using pressure-vibration information coordinated feedback in fully-mechanized caving mining according to claim 1 is characterized in that: In step S5, the closing condition of the coal discharge port is: the mass proportion of gangue in the total discharged coal gangue exceeds one-fifth.

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