A wireless microseismic positioning system and method for mines

Abstract

The present invention discloses a wireless microseismic positioning system and method for mining, wherein the system includes: a microseismic signal acquisition module for acquiring microseismic signals to be processed; a signal processing module for filtering the microseismic signals to be processed; a wireless transmission module for transmitting the filtered microseismic signals to the positioning analysis module; an analysis and positioning module for analyzing the microseismic signals to obtain the source position; and an error correction module for obtaining a more accurate source point according to the source position. The present invention implements filtering of microseismic signals through discrete wavelet transform, reduces data errors, and makes the source position analysis more accurate. At the same time, the source position is preliminarily obtained through an offset imaging method, and a more accurate source point is obtained by constructing a curve graph showing the offset value changing with position.

Description

Technical Field

[0001] The invention belongs to the technical field of microseismic monitoring, and in particular relates to a wireless microseismic positioning system and method for mines. Background Art

[0002] Microseismicity refers to the vibrations in the form of seismic waves generated when coal and rock break in a local area. Before the occurrence of underground coal mine disasters such as rock burst, roof fall, collapse, rock burst, coal and gas outburst, etc., some microseismic signals will be generated. If these microseismic signals can be monitored in real time and prevented in time, the losses caused by the disasters can be reduced to a great extent.

[0003] Microseismic monitoring technology is a geophysical technology based on acoustic emission and seismology. It monitors the impact of production activities and underground conditions by observing and analyzing small earthquake events generated during production activities. One of the main tasks of microseismic monitoring technology is to determine the location of the earthquake source, that is, microseismic positioning. Microseismic positioning generally refers to determining the longitude, latitude, depth and time of the microseismic source, and giving an appropriate evaluation of the positioning results.

[0004] However, in traditional microseismic monitoring technology, the application of many algorithms often makes it difficult to accurately calculate the specific location of the microseismic source. At the same time, existing technologies rarely have accurate solutions for optimizing the source location. Summary of the invention

[0005] The purpose of the present invention is to provide a wireless microseismic positioning system and method for mining to solve the problems existing in the above-mentioned prior art.

[0006] On the one hand, in order to achieve the above-mentioned purpose, the present invention provides a wireless microseismic positioning system for mining, comprising a microseismic signal acquisition module, a signal processing module, a wireless transmission module, an analysis and positioning module and an error correction module connected in sequence, wherein:

[0007] The microseismic signal acquisition module is used to acquire the microseismic signal to be processed;

[0008] The signal processing module is used to perform filtering processing on the microseismic signal to be processed;

[0009] The wireless transmission module is used to transmit the microseismic signal after filtering to the positioning analysis module;

[0010] The analysis and positioning module is used to analyze the microseismic signal after filtering to obtain the initial source position;

[0011] The error correction module is used to obtain the earthquake source position according to the initial earthquake source position.

[0012] Optionally, the microseismic signal acquisition module includes a plurality of geophones, which are arranged on the ground of the monitoring area and are used to receive microseismic signals in the form of direct waves.

[0013] Optionally, the signal processing module uses a sliding window and median filtering method to extract the noise signal in the microseismic signal, and performs discrete wavelet transform on the microseismic signal to remove the noise signal, and performs discrete wavelet transform again to obtain the microseismic signal with the noise removed.

[0014] Optionally, the analysis and positioning module obtains frequency domain signals of microseismic signals detected by several detectors in the microseismic signal acquisition module, performs cross-correlation operation on the frequency domain signals of the several detectors, obtains interference images and coherent data, offsets the coherent data, obtains interference results of the frequency domain signals of the several detectors in the time domain, calculates the offset value according to the interference result, and takes the detection position of the detector corresponding to the maximum offset value as the initial source position.

[0015] Optionally, after obtaining the initial source position, the error correction module divides the square area into square areas with a side length of 5 km with the detector corresponding to the maximum offset value as the center, obtains the source correction area, and divides the grids in the source correction area at intervals of 100 m, obtains the microseismic signals of all grids respectively, calculates the offset value according to the microseismic signals of all grids, constructs a curve graph according to the change of the offset value with distance, and takes the point with the largest offset value in the curve graph as the source position.

[0016] On the other hand, to achieve the above-mentioned purpose, the present invention provides a mine wireless microseismic positioning method, comprising the following steps:

[0017] Acquire a microseismic signal to be processed; the microseismic signal is a direct wave signal received by a plurality of geophones;

[0018] Performing filtering processing on the microseismic signal to be processed;

[0019] Transmitting and analyzing the filtered microseismic signal to obtain an initial earthquake source position;

[0020] The earthquake source position is obtained according to the initial earthquake source position.

[0021] Optionally, the process of filtering the microseismic signal to be processed includes:

[0022] The noise signal in the microseismic signal is extracted by using a sliding window and a median filter method, and the microseismic signal is subjected to a discrete wavelet transform to remove the noise signal, and the signal after the noise is removed is subjected to a discrete wavelet transform again to obtain a microseismic signal after the noise is removed.

[0023] Optionally, the process of analyzing the microseismic signal after filtering includes:

[0024] Acquire frequency domain signals of a plurality of the microseismic signals, and perform cross-correlation operations on the plurality of the frequency domain signals to acquire interference images and coherent data;

[0025] offsetting the coherent data to obtain interference results of frequency domain signals of a plurality of detectors in the time domain;

[0026] The offset value is calculated according to the interference result, and the position of the microseismic signal corresponding to the maximum offset value is used as the initial source position.

[0027] Optionally, the process of obtaining the earthquake source position according to the initial earthquake source position includes:

[0028] Taking the initial earthquake source position as the center and dividing the square area with a side length of 5 km, obtaining the earthquake source correction area, and dividing the grid in the earthquake source area with an interval of 100 m;

[0029] The microseismic signals of all grids are obtained respectively, and the offset values ​​are calculated according to the microseismic signals of all grids;

[0030] A curve graph is constructed according to the variation of the offset value with the distance, and the point with the largest offset value in the curve graph is taken as the earthquake source position.

[0031] The technical effects of the present invention are:

[0032] The present invention proposes a wireless microseismic positioning system and method for mining, which realizes filtering processing of microseismic signals through discrete wavelet transform, reduces data errors, makes the source position analysis more accurate, and at the same time preliminarily obtains the source position through the offset imaging method, and obtains a more accurate source point by constructing a curve graph of the offset value changing with the position. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0034] Figure 1 Schematic diagram of the structure of a wireless microseismic positioning system for mining in an embodiment of the present invention;

[0035] Figure 2 The figure is a flow chart of a mine wireless microseismic positioning method in an embodiment of the present invention. DETAILED DESCRIPTION

[0036] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0037] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0038] Embodiment 1

[0039] like Figure 1 As shown, in this embodiment, a wireless microseismic positioning system for mining is provided, comprising a microseismic signal acquisition module, a signal processing module, a wireless transmission module, an analysis and positioning module, and an error correction module connected in sequence, specifically:

[0040] The microseismic signal acquisition module is used to acquire the microseismic signals to be processed; the detector has good linear direct wave detection characteristics, and the requirements for the working voltage and current structure are relatively low, which can ensure the stability of the data. Therefore, the detector is selected in the microseismic signal acquisition module of this embodiment, and several detectors are set on the ground of the monitoring area to receive microseismic signals in the form of direct waves.

[0041] This embodiment uses a sampling sliding window and median filtering method to extract noise from microseismic signals. Median filtering sorts the grayscale values ​​of pixels in a sliding window and replaces the original grayscale value of the center pixel of the window with its median value. It is a nonlinear image smoothing method that has a good noise suppression effect and can effectively protect the edge from being blurred while suppressing random noise.

[0042] After acquiring the signal, the microseismic signal to be processed is transmitted to the signal conversion module for filtering processing. The noise signal in the microseismic signal is extracted by the sliding window and median filtering method, and then the microseismic signal is subjected to discrete wavelet transform to remove the noise signal. After performing discrete wavelet transform again, the microseismic signal with noise removed is obtained.

[0043] In traditional earthquake source detection technology, data transmission mostly relies on wired connections between sensors, which results in high engineering costs and is prone to unstable factors such as line failures. Therefore, this embodiment uses wireless transmission technology for data exchange. After the microseismic signal is de-noised, the signal is transmitted to the positioning analysis module for analysis through the wireless transmission module.

[0044] Seismic wave migration imaging technology mainly calculates the correlation between data sampling points without obtaining the initial position of the earthquake source. Therefore, there are not many requirements for the position setting of the detector. Its specific principle is: the analysis and positioning module obtains the frequency domain signals of the microseismic signals detected by several detectors in the microseismic signal acquisition module, and performs cross-correlation operation on the frequency domain signals of several detectors to obtain coherent data, offsets the coherent data, obtains the interference results of the frequency domain signals of several detectors in the time domain, calculates the offset value according to the interference result, and takes the position of the detector corresponding to the maximum offset value as the initial earthquake source position.

[0045] After obtaining the initial source position, the error correction module divides the square area into 5km-long squares with the initial source position as the center, obtains the source correction area, and divides the source area into grids at intervals of 100m. The microseismic signals in all grids are obtained respectively, and the offset value is calculated according to the microseismic signals of all grids. A curve graph is constructed according to the change of the offset value with distance. The change of the microseismic signal can be shown by the curve graph. At this time, the point with the largest offset value in the curve graph is the source point.

[0046] like Figure 2 As shown, this embodiment provides a mine wireless microseismic positioning method, including the following steps:

[0047] Acquire a microseismic signal to be processed; the microseismic signal is a direct wave signal received by a plurality of detectors; filter the microseismic signal to be processed; transmit and analyze the filtered microseismic signal to obtain an initial source position; and obtain the source position according to the initial source position.

[0048] As a preferred embodiment of the present invention, the process of filtering the microseismic signal to be processed includes: using a sliding window and a median filter method to extract a noise signal from the microseismic signal, performing a discrete wavelet transform on the microseismic signal to remove the noise signal, and performing a discrete wavelet transform on the signal after the noise is removed again to obtain a microseismic signal after the noise is removed.

[0049] As a preferred embodiment of the present invention, the process of analyzing the microseismic signal after filtering includes: obtaining frequency domain signals of several microseismic signals, and performing cross-correlation operations on the several frequency domain signals to obtain interference images and coherent data; offsetting the coherent data to obtain interference results of the frequency domain signals of several detectors in the time domain; calculating the offset value according to the interference result, and taking the position of the microseismic signal corresponding to the maximum offset value as the initial source position.

[0050] As a preferred embodiment of the present invention, the process of obtaining the epicenter position according to the initial epicenter position includes: taking the initial epicenter position as the center, dividing the square area with a side length of 5 km, obtaining the epicenter correction area, and dividing the epicenter area into grids at intervals of 100 m; respectively obtaining the microseismic signals of all grids, and calculating the offset value according to the microseismic signals of all grids; constructing a curve graph according to the change of the offset value with distance, and taking the point with the largest offset value in the curve graph as the epicenter position.

[0051] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the method disclosed in the embodiment, since it corresponds to the system disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the system part description.

[0052] The above is only a preferred specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A wireless microseismic positioning system for mines, characterized in that: It includes a microseismic signal acquisition module, a signal processing module, a wireless transmission module, an analysis and positioning module and an error correction module which are connected in sequence, wherein: The microseismic signal acquisition module is used to acquire the microseismic signal to be processed; The signal processing module is used to perform filtering processing on the microseismic signal to be processed; The wireless transmission module is used to transmit the microseismic signal after filtering to the analysis and positioning module; The analysis and positioning module is used to analyze the microseismic signal after filtering to obtain the initial source position; The error correction module is used to obtain the earthquake source position according to the initial earthquake source position; The analysis and positioning module obtains frequency domain signals of microseismic signals detected by several geophones in the microseismic signal acquisition module, performs cross-correlation operation on the frequency domain signals of the several geophones, obtains interference images and coherent data, offsets the coherent data, obtains interference results of the frequency domain signals of the several geophones in the time domain, calculates the offset value according to the interference result, and uses the detection position of the geophone corresponding to the maximum offset value as the initial source position; After obtaining the initial source position, the error correction module divides the square area into squares with a side length of 5 km and takes the detector corresponding to the maximum offset value as the center to obtain the source correction area, and divides the grids in the source correction area at intervals of 100 m, obtains the microseismic signals of all grids respectively, calculates the offset value according to the microseismic signals of all grids, constructs a curve graph according to the change of the offset value with distance, and takes the point with the largest offset value in the curve graph as the source position.

2. The mine wireless microseismic positioning system according to claim 1, characterized in that: The microseismic signal acquisition module includes a plurality of geophones, which are arranged on the ground of the monitoring area and are used to receive microseismic signals in the form of direct waves.

3. The mine wireless microseismic positioning system according to claim 1, characterized in that: The signal processing module uses a sliding window and median filtering method to extract the noise signal in the microseismic signal, and performs discrete wavelet transform on the microseismic signal to remove the noise signal, and after performing discrete wavelet transform again, obtains the microseismic signal with the noise removed.

4. A mine-based wireless microseismic positioning method, characterized in that: The following steps are involved: Acquire a microseismic signal to be processed; the microseismic signal is a direct wave signal received by a plurality of geophones; Performing filtering processing on the microseismic signal to be processed; Transmit and analyze the filtered microseismic signal to obtain the initial source position; Acquire the earthquake source position according to the initial earthquake source position; The process of analyzing the microseismic signal after filtering includes: Acquire frequency domain signals of a plurality of the microseismic signals, and perform cross-correlation operations on the plurality of the frequency domain signals to acquire interference images and coherent data; offsetting the coherent data to obtain interference results of frequency domain signals of a plurality of detectors in the time domain; Calculate the offset value according to the interference result, and take the position of the microseismic signal corresponding to the maximum offset value as the initial source position; The process of obtaining the earthquake source position according to the initial earthquake source position includes: Taking the initial earthquake source position as the center and dividing the square area with a side length of 5 km, obtaining the earthquake source correction area, and dividing the grid in the earthquake source area with an interval of 100 m; The microseismic signals of all grids are obtained respectively, and the offset values ​​are calculated according to the microseismic signals of all grids; A curve graph is constructed according to the variation of the offset value with the distance, and the point with the largest offset value in the curve graph is taken as the earthquake source position.

5. The mine wireless microseismic positioning method according to claim 4, characterized in that: The process of filtering the microseismic signal to be processed includes: The noise signal in the microseismic signal is extracted by using a sliding window and a median filter method, and the microseismic signal is subjected to a discrete wavelet transform to remove the noise signal, and the signal after the noise is removed is subjected to a discrete wavelet transform again to obtain a microseismic signal after the noise is removed.

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