Mine micro-seismic monitoring signal triggering method and system

Abstract

The invention provides a mine micro-seismic monitoring signal triggering method and system, and belongs to the technical field of signal processing, and the method comprises the steps: obtaining an original waveform signal time sequence of an original monitoring signal, obtaining an envelope function of the original waveform signal time sequence, and extracting the signal characteristics of the original monitoring signal according to the envelope function; according to the signal characteristics, calculating a reasonable noise range and a signal-to-noise ratio of the original monitoring signal, and according to the reasonable noise range and the signal-to-noise ratio, judging whether the original monitoring signal meets a signal triggering condition so as to determine a triggering point; and correcting the trigger point to obtain the actual trigger time of the micro-seismic monitoring signal. According to the invention, working condition self-adaptive mine micro-seismic monitoring signal triggering can be realized, manual adjustment of triggering parameters is not needed, the monitoring of the mine micro-seismic monitoring signal is more flexible, and the method adapts to variable ground noise characteristic conditions among different mines.

Description

Technical Field

[0001] The present invention relates to the technical field of signal processing, and in particular to a method and system for triggering a mine microseismic monitoring signal. Background Art

[0002] Mine microseismic monitoring signals have a wide range of application value in geotechnical engineering and safety monitoring engineering fields such as mines, tunnels, and slope management. In order to accurately monitor mine microseismic monitoring signals, it is usually necessary to obtain the occurrence time of mine microseismic monitoring signals. The traditional mine microseismic monitoring signal trigger detection method usually sets fixed trigger parameters for a fixed environment to determine whether a mine microseismic monitoring signal has been generated, and the monitoring method is not flexible enough. Summary of the invention

[0003] In view of this, the purpose of the present invention is to overcome the deficiencies in the prior art and provide a method and system for triggering a microseismic monitoring signal in a mine to achieve flexible monitoring of microseismic monitoring signals in a mine.

[0004] In a first aspect, the present application provides a method for triggering a microseismic monitoring signal in a mine, comprising:

[0005] Obtaining an original waveform signal time series of an original monitoring signal, and obtaining an envelope function of the original waveform signal time series;

[0006] Extracting the signal characteristics of the original monitoring signal according to the envelope function;

[0007] Calculate the reasonable noise range and signal-to-noise ratio of the original monitoring signal according to the signal characteristics, and determine whether the original monitoring signal meets the signal trigger condition according to the reasonable noise range and the signal-to-noise ratio to determine the trigger point;

[0008] The trigger point is corrected to obtain the actual trigger time of the microseismic monitoring signal.

[0009] In an optional embodiment, the signal characteristics further include a pre-trigger background noise characteristic, a post-trigger signal characteristic, and a trigger continuous signal characteristic, and the signal characteristics of the original monitoring signal are obtained, including:

[0010] According to the envelope function, the calculation formulas of the pre-trigger background noise feature, the post-trigger signal feature and the trigger continuous signal feature are determined respectively:

[0011]

[0012] in, is the noise floor feature before triggering, s2(t) is the signal feature after triggering, is the trigger continuous signal feature, u(t) is the envelope function, m is the length of the background noise window before the trigger, n is the length of the signal window after the trigger, l is the length of the delayed signal window after the trigger, and d is the trigger duration.

[0013] In an optional implementation, calculating the signal-to-noise ratio of the original monitoring signal according to the signal feature includes:

[0014] According to the signal characteristics, the instant trigger signal-to-noise ratio and the signal delay trigger signal-to-noise ratio of the original monitoring signal are calculated respectively:

[0015]

[0016] Among them, r1(t) is the immediate trigger signal-to-noise ratio, and r2(t) is the signal delay trigger signal-to-noise ratio.

[0017] In another embodiment, the reasonable noise range is obtained by:

[0018] According to the envelope function, the calculation formula for determining the reasonable noise range is:

[0019]

[0020] h1(t) is the reasonable noise range at time t, m is the signal noise window length, is the mean value of the signal envelope in the m-length window before time t, σ(u[tm:t]) is the standard deviation of the signal envelope in the m-length window before time t, and α is the weight of the signal noise range that can be allowed not to trigger.

[0021] In an optional implementation, the signal trigger condition further includes an immediate trigger ratio threshold and a delayed trigger ratio threshold, and the acquisition method of the immediate trigger ratio threshold and the delayed trigger ratio threshold includes:

[0022] Acquire background noise data, and select a vibration signal with the lowest amplitude expected to be triggered according to the background noise data;

[0023] The vibration signal signal-to-noise ratio is determined according to the vibration signal with the lowest amplitude, and the immediate trigger ratio threshold and the delayed trigger ratio threshold are determined according to the vibration signal signal-to-noise ratio.

[0024] In an optional implementation manner, the determining whether the original monitoring signal satisfies the signal triggering condition includes:

[0025] Determining whether the envelope function exceeds the reasonable noise range;

[0026] If it exceeds, determining whether the instant trigger signal-to-noise ratio of the signal is greater than the instant trigger ratio threshold;

[0027] If it is greater than, determining whether the signal delay trigger signal-to-noise ratio is greater than the delay trigger ratio threshold;

[0028] If it is greater, it is determined that the original monitoring signal meets the signal trigger condition.

[0029] In an optional implementation manner, the correcting the trigger point to obtain the actual trigger time of the microseismic monitoring signal includes:

[0030] The actual trigger time of the microseismic monitoring signal is calculated based on the derivative at the trigger point:

[0031]

[0032] Where t is the trigger point, t0 is the actual trigger time, u(t) is the envelope function, and u(t) ′ is the derivative of the envelope function at the trigger point t;

[0033] And the derivative of the discrete vibration signal envelope function at the trigger point t is calculated by Taylor expansion:

[0034]

[0035] Where, f is the sampling rate of microseismic monitoring signals.

[0036] In a second aspect, the present application provides a mine microseismic monitoring signal triggering system, comprising:

[0037] A signal preprocessing module, used to obtain an original waveform signal time series of an original monitoring signal and to obtain an envelope function of the original waveform signal time series;

[0038] A multi-window signal feature characterization module, used to extract the signal features of the original monitoring signal according to the envelope function;

[0039] A trigger point determination module, used to calculate a reasonable noise range and a signal-to-noise ratio of the original monitoring signal according to the signal characteristics, and determine whether the original monitoring signal meets a signal trigger condition according to the reasonable noise range and the signal-to-noise ratio to determine a trigger point;

[0040] The trigger point correction module is used to correct the trigger point to obtain the actual trigger time of the microseismic monitoring signal.

[0041] The embodiments of the present invention have the following beneficial effects:

[0042] The mine microseismic monitoring signal triggering method provided by the present invention realizes the triggering of mine microseismic monitoring signals adaptive to working conditions by dynamically acquiring the envelope function and signal-to-noise ratio of the original monitoring signal and judging whether it meets the signal triggering conditions. There is no need to manually adjust the trigger parameters, thus making the monitoring of mine microseismic monitoring signals more flexible.

[0043] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and understandable, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0045] Figure 1 A schematic diagram of a flow chart of a method for triggering a microseismic monitoring signal in a mine provided in an embodiment of the present application;

[0046] Figure 2 A schematic diagram of a method for triggering a mine microseismic monitoring signal provided in an embodiment of the present application;

[0047] Figure 3 A flow chart of a signal trigger determination method provided in an embodiment of the present application;

[0048] Figure 4 A schematic diagram of a mine microseismic monitoring signal triggering example provided in an embodiment of the present application;

[0049] Figure 5 A schematic diagram of the framework structure of a mine microseismic monitoring signal processing system provided in an embodiment of the present application.

[0050] Description of main component symbols:

[0051] 500. Mining microseismic monitoring signal triggering system; 501. Signal preprocessing module; 502. Multi-window signal feature characterization module; 503. Trigger point determination module; 504. Trigger point correction module. DETAILED DESCRIPTION

[0052] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0053] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0054] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of the template are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0055] Example 1

[0056] See also Figure 1 , Figure 1 A schematic flow chart of a method for triggering a mine microseismic monitoring signal provided in this embodiment, which can be used to determine the triggering time of a mine microseismic monitoring signal, includes:

[0057] S101, obtaining an original waveform signal time series of an original monitoring signal, and obtaining an envelope function of the original waveform signal time series.

[0058] The original waveform signal of the mine monitoring signal is continuously obtained and converted into a time series. For example, for the original waveform time series of length k, it can be recorded as w(t) = [w1, w2, ..., w k ].

[0059] See also Figure 2 , Figure 2 Schematic diagram of the mine microseismic monitoring signal triggering method provided in this embodiment.

[0060] After obtaining the original waveform signal time series, take its envelope function u(t)=U[w(t)]. The envelope function is usually used to describe the change of the local maximum value of the signal.

[0061] S102: Extracting signal features of the original monitoring signal according to the envelope function.

[0062] The signal characteristics include a pre-trigger background noise characteristic, a post-trigger signal characteristic, and a trigger-continuous signal characteristic. The signal characteristics of the original monitoring signal are obtained, including:

[0063] According to the envelope function, the calculation formulas of the pre-trigger background noise feature, the post-trigger signal feature and the trigger continuous signal feature are determined respectively:

[0064]

[0065] in, is the noise floor feature before triggering, s2(t) is the signal feature after triggering, is the trigger continuous signal feature, m is the length of the background noise window before the trigger, n is the length of the signal window after the trigger, l is the length of the delayed signal window after the trigger, and d is the trigger duration.

[0066] S103. Calculate a reasonable noise range and a signal-to-noise ratio of the original monitoring signal according to the signal characteristics, and determine whether the original monitoring signal satisfies a signal trigger condition according to the reasonable noise range and the signal-to-noise ratio to determine a trigger point.

[0067] After the signal characteristics are obtained, the instant trigger signal-to-noise ratio and the signal delay trigger signal-to-noise ratio of the original monitoring signal can be calculated according to the signal characteristics:

[0068]

[0069] Among them, r1(t) is the immediate trigger signal-to-noise ratio, and r2(t) is the signal delay trigger signal-to-noise ratio.

[0070] Since the envelope function is the change of the local maximum value of the signal, the reasonable noise range h1(t) of the original waveform signal time series at time t should be the weighted sum of the mean and standard deviation of the signal before time t (which can be calculated using the Welford method), that is:

[0071]

[0072] Among them, h1(t) is the reasonable noise range at time t, m is the signal noise window length, is the mean value of the signal envelope in the m-length window before time t, σ(u[tm:t]) is the standard deviation of the signal envelope in the m-length window before time t, and α is the weight of the signal noise range that can be allowed not to trigger.

[0073] In one embodiment, after determining a reasonable noise range, background noise data can be selected from the original monitoring signal, and the background noise window length m before triggering can be determined based on the background noise frequency and background noise fluctuation of the background noise data. The signal noise range weight α can be determined based on the background noise variation amplitude, and the window should be able to receive multiple complete peaks of the background noise signal.

[0074] Then, based on the background noise data, select the vibration signal waveform that is expected to be triggered, and select the post-trigger signal window length n and the post-trigger delay signal window length l according to the main frequency range of the vibration signal and the sensor receiving frequency range. The window should be able to receive multiple complete peaks of the vibration signal.

[0075] Then, according to the vibration signal waveform expected to be triggered, the vibration signal with the lowest amplitude expected to be triggered is selected, and the immediate trigger ratio threshold h2 and the delayed trigger ratio threshold h3 are determined according to the vibration signal noise ratio. In addition, the minimum length vibration signal expected to be triggered is selected, and the trigger duration d is determined according to the duration of the vibration signal.

[0076] See also Figure 3 , step S103 includes:

[0077] S1031. Determine whether the envelope function exceeds the reasonable noise range.

[0078] In order to achieve accurate monitoring of the microseismic monitoring signal, this embodiment sets three trigger conditions to determine in sequence or simultaneously whether the microseismic monitoring signal is triggered.

[0079] First, it is determined whether the envelope function exceeds the reasonable noise range, that is, whether u(t)>h1(t) holds.

[0080] S1032: If exceeded, determine whether the instant trigger signal-to-noise ratio of the signal is greater than the instant trigger ratio threshold.

[0081] If u(t)>h1(t), then determine whether the instant trigger signal-to-noise ratio of the signal is greater than the instant trigger ratio threshold, that is, determine whether r1(t)>h2 is true.

[0082] S1033: If it is greater than, determine whether the signal delay trigger signal-to-noise ratio is greater than the delay trigger ratio threshold.

[0083] If r1(t)>h2, then determine whether the signal delay trigger signal-to-noise ratio is greater than the delay trigger ratio threshold, that is, whether r2(t)>h3 is true.

[0084] S1034: If it is greater than, determine that the original monitoring signal meets the signal trigger condition.

[0085] If the above three trigger conditions are all met, it is determined that the original monitoring signal meets the signal trigger condition, that is, it is determined that a microseismic monitoring signal is generated, or the monitoring condition of the microseismic monitoring signal is triggered.

[0086] S104: Correct the trigger point to obtain the actual trigger time of the microseismic monitoring signal.

[0087] The judgment process of the above three trigger conditions can be performed sequentially to save judgment time, or the judgment order can be adjusted according to needs, or the judgment of the three conditions can be performed simultaneously.

[0088] After determining that a microseismic monitoring signal has been generated, the actual triggering time of the microseismic monitoring signal can be calculated based on the derivative at the triggering point:

[0089]

[0090] Where t is the trigger point, t0 is the actual trigger time, u(t) is the envelope function, and u(t) ′ is the derivative of the envelope function at the trigger point t;

[0091] And the derivative of the discrete vibration signal envelope function at the trigger point t is calculated by Taylor expansion:

[0092]

[0093] Among them, f is the sampling rate of the microseismic monitoring signal. Through the above formula, the actual trigger time of the microseismic monitoring signal can be calculated according to the trigger point, thereby improving the accuracy of monitoring.

[0094] This embodiment realizes the triggering of mine microseismic monitoring signals that are adaptive to working conditions by dynamically calculating the noise range and the trigger threshold, without the need to manually adjust the trigger parameters, thereby making the monitoring of mine microseismic monitoring signals more flexible. Moreover, by increasing the post-trigger delay window setting, it is ensured that the trigger signal waveform is a continuous vibration signal, thereby avoiding frequent false triggering caused by short-term background noise interference in working conditions.

[0095] For the triggering example of the mine microseismic monitoring signal in this embodiment, please refer to Figure 4 , the horizontal axis is the number of signal sampling points, and the vertical axis is the waveform and the characteristic value at the corresponding time. The vertical dotted line is the trigger position of the traditional long and short time window method, the vertical dotted horizontal line is the trigger position of the adaptive multi-window mine microseismic monitoring signal trigger method, and the vertical solid line is the manual picking reference trigger position. It can be seen that the trigger arrival position calculated by this embodiment is basically consistent with the manual picking, and the phenomenon of early triggering of the traditional long and short time window method due to background noise can be avoided.

[0096] Example 2

[0097] Please refer to Figure 5 , Figure 5 A schematic diagram of a framework structure of a mine microseismic monitoring signal triggering system 500 provided in this embodiment includes:

[0098] The signal preprocessing module 501 is used to obtain the original waveform signal time series of the original monitoring signal, and obtain the envelope function of the original waveform signal time series.

[0099] The multi-window signal feature characterization module 502 is used to extract the signal features of the original monitoring signal according to the envelope function.

[0100] The trigger point determination module 503 is used to calculate the reasonable noise range and signal-to-noise ratio of the original monitoring signal according to the signal characteristics, and determine whether the original monitoring signal meets the signal trigger condition according to the reasonable noise range and the signal-to-noise ratio to determine the trigger point.

[0101] The correction module 504 is used to correct the trigger point to obtain the actual trigger time of the microseismic monitoring signal.

[0102] It can be understood that the implementation method of the mine microseismic monitoring signal triggering method described in the above embodiment 1 is also applicable to this embodiment, so it will not be repeated here.

[0103] In several embodiments provided in the present application, it should be understood that the disclosed apparatus and method can also be implemented in other ways. The apparatus embodiments described above are merely schematic, for example, the flowcharts and structure diagrams in the accompanying drawings show the possible architecture, functions and operations of the apparatus, method and computer program product according to multiple embodiments of the present application. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of a code, and a module, a program segment or a part of a code contains one or more executable instructions for implementing a specified logical function. It should also be noted that in an alternative implementation, the functions marked in the box can also occur in a different order from that marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the structure diagram and / or the flow diagram, and the combination of boxes in the structure diagram and / or the flow diagram, can be implemented with a dedicated hardware-based system that performs a specified function or action, or can be implemented with a combination of dedicated hardware and computer instructions.

[0104] In addition, the functional modules or units in the various embodiments of the present application may be integrated together to form an independent part, or each module may exist separately, or two or more modules may be integrated to form an independent part.

[0105] If the function is implemented in the form of a software function module and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a smart phone, a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the various embodiments of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0106] The above are only specific implementation methods of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be covered by the protection scope of the present application.

[0107] In all examples shown and described herein, any specific values ​​should be interpreted as merely exemplary and not as limiting, and thus other examples of the exemplary embodiments may have different values.

[0108] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0109] The above embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present invention. It should be pointed out that, for those of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention.

Claims

1. A method for triggering a microseismic monitoring signal in a mine, characterized in that: include: Obtaining an original waveform signal time series of an original monitoring signal, and obtaining an envelope function of the original waveform signal time series; Extracting the signal characteristics of the original monitoring signal according to the envelope function; Calculate the reasonable noise range and signal-to-noise ratio of the original monitoring signal according to the signal characteristics, and determine whether the original monitoring signal meets the signal trigger condition according to the reasonable noise range and the signal-to-noise ratio to determine the trigger point; The trigger point is corrected to obtain the actual trigger time of the microseismic monitoring signal.

2. The method for triggering a microseismic monitoring signal in a mine according to claim 1, characterized in that: The signal characteristics include a pre-trigger background noise characteristic, a post-trigger signal characteristic, and a trigger-continuous signal characteristic. The signal characteristics of the original monitoring signal are obtained, including: According to the envelope function, the calculation formulas of the pre-trigger background noise feature, the post-trigger signal feature and the trigger continuous signal feature are determined respectively: in, is the noise floor feature before triggering, s2(t) is the signal feature after triggering, is the trigger continuous signal feature, u(t) is the envelope function, m is the length of the background noise window before the trigger, n is the length of the signal window after the trigger, l is the length of the delayed signal window after the trigger, and d is the trigger duration.

3. The method for triggering a microseismic monitoring signal in a mine according to claim 2, characterized in that: Calculating the signal-to-noise ratio of the original monitoring signal according to the signal feature includes: According to the signal characteristics, the instant trigger signal-to-noise ratio and the signal delay trigger signal-to-noise ratio of the original monitoring signal are calculated respectively: Among them, r1(t) is the immediate trigger signal-to-noise ratio, and r2(t) is the signal delay trigger signal-to-noise ratio.

4. The method for triggering a mine microseismic monitoring signal according to claim 3, characterized in that: The method for obtaining the reasonable noise range includes: According to the envelope function, the calculation formula for determining the reasonable noise range is: in, is the mean value of the signal envelope in the window of length m before time t, h1(t) is the reasonable noise range at time t, m is the length of the signal noise window, σ(u[tm:t]) is the standard deviation of the signal envelope in the window of length m before time t, and α is the weight of the signal noise range that can be allowed not to trigger.

5. The method for triggering a microseismic monitoring signal in a mine according to claim 4, characterized in that: The signal trigger condition also includes an immediate trigger ratio threshold and a delayed trigger ratio threshold. The acquisition method of the immediate trigger ratio threshold and the delayed trigger ratio threshold includes: Acquire background noise data, and select a vibration signal with the lowest amplitude expected to be triggered according to the background noise data; The vibration signal signal-to-noise ratio is determined according to the vibration signal with the lowest amplitude, and the immediate trigger ratio threshold and the delayed trigger ratio threshold are determined according to the vibration signal signal-to-noise ratio.

6. The method for triggering a microseismic monitoring signal in a mine according to claim 5, characterized in that: The determining whether the original monitoring signal satisfies the signal triggering condition includes: Determining whether the envelope function exceeds the reasonable noise range; If exceeded, determining whether the instant trigger signal-to-noise ratio of the signal is greater than an instant trigger ratio threshold; If it is greater than, determining whether the signal delay trigger signal-to-noise ratio is greater than the delay trigger ratio threshold; If it is greater, it is determined that the original monitoring signal meets the signal trigger condition.

7. The method for triggering a microseismic monitoring signal in a mine according to claim 1, characterized in that: The correcting the trigger point to obtain the actual trigger time of the microseismic monitoring signal includes: The actual trigger time of the microseismic monitoring signal is calculated based on the derivative at the trigger point: Where t is the trigger point, t0 is the actual trigger time, u(t) is the envelope function, and u(t) ′ is the derivative of the envelope function at the trigger point t; And the derivative of the discrete vibration signal envelope function at the trigger point t is calculated by Taylor expansion: Where, f is the sampling rate of microseismic monitoring signals.

8. A mine microseismic monitoring signal triggering system, characterized in that: include: A signal preprocessing module, used to obtain an original waveform signal time series of an original monitoring signal, and to obtain an envelope function of the original waveform signal time series; A multi-window signal feature characterization module, used to extract the signal features of the original monitoring signal according to the envelope function; A trigger point judgment module is used to calculate the reasonable noise range and signal-to-noise ratio of the original monitoring signal according to the signal characteristics, and judge whether the original monitoring signal meets the signal trigger condition to determine the trigger point according to the reasonable noise range and the signal-to-noise ratio; The trigger point correction module is used to correct the trigger point to obtain the actual trigger time of the microseismic monitoring signal.

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