A method and system for triggering microseismic monitoring signals in mines

Abstract

The present invention provides a method and system for triggering a microseismic monitoring signal for a mine, belonging to the field of signal processing technology. The method comprises: obtaining an original waveform signal time series of an original monitoring signal, obtaining an envelope function of the original waveform signal time series, extracting signal characteristics of the original monitoring signal based on the envelope function; calculating a reasonable noise range and a signal-to-noise ratio of the original monitoring signal based on the signal characteristics; judging whether the original monitoring signal meets a signal triggering condition based on the reasonable noise range and the signal-to-noise ratio to determine a trigger point; and correcting the trigger point to obtain the actual trigger time of the microseismic monitoring signal. The present invention can realize working condition-adaptive triggering of a mine microseismic monitoring signal without the need for manual adjustment of trigger parameters, making the monitoring of mine microseismic monitoring signals more flexible and adaptable to the variable background noise characteristic conditions between different mines.

Description

Technical Field

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

[0002] Mine microseismic monitoring signals have extensive application value in geotechnical engineering and safety monitoring projects such as mines, tunnels, and slope management. Accurately monitoring these signals requires obtaining the exact moment they occur. Traditional trigger detection methods for mine microseismic monitoring signals typically rely on fixed trigger parameters to determine whether a signal has occurred, targeting a specific environment. This approach is inflexible. 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 microseismic monitoring signals in mines to achieve flexible monitoring of microseismic monitoring signals in mines.

[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] Calculating a reasonable noise range and a signal-to-noise ratio of the original monitoring signal based on the signal characteristics, and determining whether the original monitoring signal meets a signal trigger condition based on the reasonable noise range and the signal-to-noise ratio to determine a 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 obtaining the signal characteristics of the original monitoring signal includes:

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

[0011]

[0012]

[0013]

[0014] in, To trigger the background noise characteristics, is the signal characteristic after triggering, To trigger the continuous signal feature, is the envelope function, m is the length of the background noise window before triggering, n is the length of the signal window after triggering, l is the length of the delayed signal window after triggering, d is the trigger duration.

[0015] In an optional embodiment, calculating the signal-to-noise ratio of the original monitoring signal according to the signal feature includes:

[0016] According to the signal characteristics, the instant trigger signal-to-noise ratio and the signal delayed trigger signal-to-noise ratio of the original monitoring signal are calculated respectively:

[0017]

[0018]

[0019] in, To instantly trigger the signal-to-noise ratio, Trigger signal-to-noise ratio for signal delay.

[0020] In another embodiment, the reasonable noise range is obtained by:

[0021] According to the envelope function, the calculation formula for determining the reasonable noise range is:

[0022]

[0023] is the reasonable noise range at time t, p is the signal noise window length, is the mean value of the signal envelope in the p-length window before time t, is the standard deviation of the signal envelope in the p-length window before time t, The weight of the signal noise range that can be allowed not to trigger.

[0024] In an optional embodiment, the signal trigger condition further includes an immediate trigger ratio threshold and a delayed trigger ratio threshold, and the immediate trigger ratio threshold and the delayed trigger ratio threshold are obtained in the following manner:

[0025] Acquire background noise data, and select a vibration signal with the lowest amplitude expected to be triggered based on the background noise data;

[0026] 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.

[0027] In an optional implementation, determining whether the original monitoring signal satisfies the signal triggering condition includes:

[0028] Determining whether the envelope function exceeds the reasonable noise range;

[0029] If exceeded, determining whether the instant trigger signal-to-noise ratio of the signal is greater than the instant trigger ratio threshold;

[0030] If it is greater than, determining whether the signal delay trigger signal-to-noise ratio is greater than the delay trigger ratio threshold;

[0031] If it is greater, it is determined that the original monitoring signal meets the signal trigger condition.

[0032] In an optional embodiment, the correcting the trigger point to obtain the actual trigger time of the microseismic monitoring signal includes:

[0033] The actual triggering time of the microseismic monitoring signal is calculated based on the derivative at the triggering point:

[0034]

[0035] Where t is the trigger point, is the actual trigger time, is the envelope function, is the derivative of the envelope function at the trigger point t;

[0036] The envelope function of the discrete vibration signal is calculated at the trigger point by Taylor expansion Derivative at time:

[0037]

[0038] in, is the sampling rate of microseismic monitoring signals.

[0039] In a second aspect, the present application provides a mine microseismic monitoring signal triggering system, comprising:

[0040] A signal preprocessing module, configured to obtain an original waveform signal time series of an original monitoring signal and obtain an envelope function of the original waveform signal time series;

[0041] A multi-window signal feature characterization module, configured to extract the signal features of the original monitoring signal according to the envelope function;

[0042] a trigger point determination module, configured to calculate a reasonable noise range and a signal-to-noise ratio of the original monitoring signal based on the signal characteristics, and determine whether the original monitoring signal satisfies a signal trigger condition based on the reasonable noise range and the signal-to-noise ratio to determine a trigger point;

[0043] The trigger point correction module is used to correct the trigger point to obtain the actual trigger time of the microseismic monitoring signal.

[0044] The embodiments of the present invention have the following beneficial effects:

[0045] The mine microseismic monitoring signal triggering method provided by the present invention dynamically obtains the envelope function and signal-to-noise ratio of the original monitoring signal and determines whether it meets the signal triggering conditions, thereby realizing working condition-adaptive mine microseismic monitoring signal triggering. There is no need to manually adjust the trigger parameters, making the monitoring of mine microseismic monitoring signals more flexible.

[0046] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0048] Figure 1 A flowchart of a method for triggering a microseismic monitoring signal in a mine provided in an embodiment of the present application;

[0049] Figure 2 A schematic diagram of a method for triggering a microseismic monitoring signal in a mine provided in an embodiment of the present application;

[0050] Figure 3 A flow chart of a signal trigger determination method provided in an embodiment of the present application;

[0051] Figure 4 A schematic diagram of a mine microseismic monitoring signal triggering example provided in an embodiment of the present application;

[0052] 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.

[0053] Description of main component symbols:

[0054] 500. Mine 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

[0055] The following describes embodiments of the present invention in detail. Examples of the embodiments 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 intended only to explain the present invention and are not to be construed as limiting the present invention.

[0056] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0057] Unless otherwise defined, all technical and scientific terms used herein have the same meanings as commonly understood by one skilled in the art to which this application belongs. The terms used in the template description herein are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0058] Example 1

[0059] See also Figure 1 , Figure 1 This is a flow chart of a method for triggering a mine microseismic monitoring signal provided in this embodiment. The method can be used to determine the triggering time of a mine microseismic monitoring signal. The method includes:

[0060] S101 : Acquire an original waveform signal time series of an original monitoring signal, and acquire an envelope function of the original waveform signal time series.

[0061] Continuously obtain the original waveform signal of the mine monitoring signal and convert it into the form of a time series. For example, for the original waveform time series of k length, it can be recorded as .

[0062] See also Figure 2 , Figure 2 This is a schematic diagram of the mine microseismic monitoring signal triggering method provided in this embodiment.

[0063] After obtaining the original waveform signal time series, take its envelope function , the envelope function is usually used to describe the changes in the local maximum of a signal.

[0064] S102: Extracting signal features of the original monitoring signal according to the envelope function.

[0065] 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:

[0066] According to the envelope function, the calculation formulas for the pre-trigger noise feature, the post-trigger signal feature, and the trigger-continuous signal feature are respectively determined:

[0067]

[0068]

[0069]

[0070] in, To trigger the background noise characteristics, is the signal characteristic after triggering, To trigger the continuous signal feature, m is the length of the background noise window before triggering, n is the length of the signal window after triggering, l is the length of the delayed signal window after triggering, d is the trigger duration.

[0071] S103. Calculate a reasonable noise range and a signal-to-noise ratio of the original monitoring signal based on the signal characteristics, and determine whether the original monitoring signal meets a signal trigger condition based on the reasonable noise range and the signal-to-noise ratio to determine a trigger point.

[0072] After obtaining the signal characteristics, the instant trigger signal-to-noise ratio and the signal delayed trigger signal-to-noise ratio of the original monitoring signal can be calculated according to the signal characteristics:

[0073]

[0074]

[0075] in, To instantly trigger the signal-to-noise ratio, Trigger signal-to-noise ratio for signal delay.

[0076] Since the envelope function is the change of the local maximum of the signal, the reasonable noise range of the original waveform signal time series at time t is It 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:

[0077] .

[0078] in, is the reasonable noise range at time t, p is the signal noise window length, is the mean value of the signal envelope in the p-length window before time t, is the standard deviation of the signal envelope in the p-length window before time t, The weight of the signal noise range that can be allowed not to trigger.

[0079] In one embodiment, after determining a reasonable noise range, background noise data can be selected from the original monitoring signal. The pre-trigger background noise window length m is determined based on the background noise frequency and background noise fluctuation of the background noise data. The signal-to-noise range weight α is determined based on the background noise variation amplitude. The window should be able to receive multiple complete peaks of the background noise signal.

[0080] Then, based on the background noise data, select the vibration signal waveform you want to trigger, and select the length of the signal window after triggering based on the main frequency range of the vibration signal and the sensor receiving frequency range. n and the length of the post-trigger delay signal window l , the window should be able to receive multiple complete peaks of the vibration signal.

[0081] Then, according to the vibration signal waveform expected to be triggered, select the vibration signal with the lowest amplitude expected to be triggered, and determine the instant trigger ratio threshold according to the vibration signal-to-noise ratio and delay trigger ratio threshold Furthermore, a vibration signal of minimum length expected to be triggered is selected, and a triggering duration d is determined according to the duration of the vibration signal.

[0082] See also Figure 3 , step S103 includes:

[0083] S1031: Determine whether the envelope function exceeds the reasonable noise range.

[0084] In order to achieve accurate monitoring of the microseismic monitoring signal, this embodiment sets three trigger conditions to determine whether the microseismic monitoring signal is triggered in sequence or simultaneously.

[0085] First, determine whether the envelope function exceeds the reasonable noise range, that is, determine whether the envelope function exceeds the reasonable noise range. Is it true?

[0086] S1032: If exceeded, determine whether the instant trigger signal-to-noise ratio of the signal is greater than the instant trigger ratio threshold.

[0087] if , then judge whether the instant trigger signal-to-noise ratio is greater than the instant trigger ratio threshold, that is, judge Is it true?

[0088] S1033: If it is greater than, determine whether the signal delay trigger signal-to-noise ratio is greater than the delay trigger ratio threshold.

[0089] if , and then determine whether the signal delay trigger signal-to-noise ratio is greater than the delay trigger ratio threshold, that is Is it true?

[0090] S1034: If it is greater than, determine that the original monitoring signal meets the signal triggering condition.

[0091] If the above three triggering conditions are all met, it is determined that the original monitoring signal meets the signal triggering condition, that is, it is determined that a microseismic monitoring signal is generated, or the monitoring condition of the microseismic monitoring signal is triggered.

[0092] S104: Correct the trigger point to obtain the actual trigger time of the microseismic monitoring signal.

[0093] 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.

[0094] 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:

[0095]

[0096] Where t is the trigger point, is the actual trigger time, is the envelope function, is the derivative of the envelope function at the trigger point t;

[0097] The envelope function of the discrete vibration signal is calculated at the trigger point by Taylor expansion Derivative at time:

[0098]

[0099] in, is the sampling rate of the microseismic monitoring signal. Through the above formula, the actual triggering time of the microseismic monitoring signal can be calculated according to the triggering point, thereby improving the accuracy of monitoring.

[0100] This embodiment realizes the triggering of mine microseismic monitoring signals that are adaptive to working conditions by dynamically calculating the noise range and trigger threshold, without the need to manually adjust the trigger parameters, making the monitoring of mine microseismic monitoring signals more flexible. Moreover, by increasing the post-trigger delay window setting, the trigger signal waveform is ensured to be a continuous vibration signal, avoiding frequent false triggering caused by short-term background noise interference in working conditions.

[0101] For an example of triggering a microseismic monitoring signal for a mine in this embodiment, please refer to Figure 4 The horizontal axis represents the number of signal sampling points, and the vertical axis represents the waveform and corresponding characteristic values. The vertical dotted line represents the trigger position of the traditional long- and short-time window method, the vertical dotted horizontal line represents the trigger position of the adaptive multi-window mine microseismic monitoring signal triggering method, and the vertical solid line represents the manually picked reference trigger position. It can be seen that the trigger arrival position calculated using this embodiment is substantially consistent with the manually picked reference position and can avoid the phenomenon of premature triggering caused by background noise in the traditional long- and short-time window method.

[0102] Example 2

[0103] Please refer to Figure 5 , Figure 5 The framework structure diagram of a mine microseismic monitoring signal triggering system 500 provided in this embodiment includes:

[0104] 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.

[0105] The multi-window signal feature characterization module 502 is configured to extract the signal features of the original monitoring signal according to the envelope function.

[0106] The trigger point determination module 503 is used to calculate the reasonable noise range and signal-to-noise ratio of the original monitoring signal based on the signal characteristics, and determine whether the original monitoring signal meets the signal trigger condition based on the reasonable noise range and the signal-to-noise ratio to determine the trigger point.

[0107] The correction module 504 is configured to correct the trigger point to obtain the actual trigger time of the microseismic monitoring signal.

[0108] 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.

[0109] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can also be implemented in other ways. The device embodiments described above are merely schematic. For example, the flowcharts and structure diagrams in the accompanying drawings show the possible architectures, functions and operations of the devices, methods and computer program products according to the 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 the code, and the module, program segment or a part of the code contains one or more executable instructions for implementing the specified logical functions. It should also be noted that in an alternative implementation, the functions marked in the box can also occur in an order different 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 flowchart, and the combination of boxes in the structure diagram and / or flowchart, can be implemented using a dedicated hardware-based system that performs the specified function or action, or can be implemented using a combination of dedicated hardware and computer instructions.

[0110] In addition, the functional modules or units in the various embodiments of the present application can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.

[0111] 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, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for enabling a computer device (which can be a smart phone, personal computer, server, or network device, etc.) to execute all or part of the steps of the various embodiments of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0112] The above is only a specific implementation method of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with this technical field can easily think of changes or replacements within the technical scope disclosed in this application, which should be covered by the protection scope of the present application.

[0113] In all examples shown and described herein, any specific values should be interpreted as merely exemplary and not limiting, and thus other examples of the exemplary embodiments may have different values.

[0114] 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, it does not need to be further defined or explained in subsequent drawings.

[0115] The above embodiments merely illustrate several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous modifications and improvements without departing from the spirit of the present invention, and these modifications and improvements fall within the scope of protection of the present invention.

Claims

1. A method for triggering microseismic monitoring signals in mines, 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; Calculating a reasonable noise range and a signal-to-noise ratio of the original monitoring signal based on the signal characteristics, and determining whether the original monitoring signal meets a signal trigger condition based on the reasonable noise range and the signal-to-noise ratio to determine a trigger point; Correcting the trigger point to obtain the actual trigger time of the microseismic monitoring signal; 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 for the pre-trigger noise feature, the post-trigger signal feature, and the trigger-continuous signal feature are respectively determined: in, To trigger the background noise characteristics, is the signal characteristic after triggering, To trigger the continuous signal feature, is the envelope function, m is the length of the background noise window before triggering, n is the length of the signal window after triggering, l is the length of the delayed signal window after triggering, d is the trigger duration.

2. The method for triggering microseismic monitoring signals in mines according to claim 1, characterized in that: Calculating the signal-to-noise ratio of the original monitoring signal according to the signal characteristics includes: According to the signal characteristics, the instant trigger signal-to-noise ratio and the signal delayed trigger signal-to-noise ratio of the original monitoring signal are calculated respectively: in, To instantly trigger the signal-to-noise ratio, Trigger signal-to-noise ratio for signal delay.

3. The method for triggering a mine microseismic monitoring signal according to claim 2, characterized in that: Methods for obtaining the reasonable noise range include: 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 p-length window before time t, is the reasonable noise range at time t, p is the signal noise window length, is the standard deviation of the signal envelope in the p-length window before time t, The weight of the signal noise range that can be allowed not to trigger.

4. The method for triggering a mine microseismic monitoring signal according to claim 3, characterized in that: 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: Acquire background noise data, and select a vibration signal with the lowest amplitude expected to be triggered based on 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.

5. The method for triggering microseismic monitoring signals in mines according to claim 4, 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 the 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.

6. The method for triggering microseismic monitoring signals in mines 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 triggering time of the microseismic monitoring signal is calculated based on the derivative at the triggering point: Where t is the trigger point, is the actual trigger time, is the envelope function, is the derivative of the envelope function at the trigger point t; The envelope function of the discrete vibration signal is calculated at the trigger point by Taylor expansion Derivative at: in, is the sampling rate of microseismic monitoring signals.

7. A mine microseismic monitoring signal triggering system, characterized in that: include: A signal preprocessing module, configured to obtain an original waveform signal time series of an original monitoring signal and obtain an envelope function of the original waveform signal time series; A multi-window signal feature characterization module, configured to extract the signal features of the original monitoring signal according to the envelope function; a trigger point determination module, configured to calculate a reasonable noise range and a signal-to-noise ratio of the original monitoring signal based on the signal characteristics, and determine whether the original monitoring signal satisfies a signal trigger condition based on the reasonable noise range and the signal-to-noise ratio to determine a trigger point; A trigger point correction module, used to correct the trigger point to obtain the actual trigger time of the microseismic monitoring signal; 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 for the pre-trigger noise feature, the post-trigger signal feature, and the trigger-continuous signal feature are respectively determined: in, To trigger the background noise characteristics, is the signal characteristic after triggering, To trigger the continuous signal feature, is the envelope function, m is the length of the background noise window before triggering, n is the length of the signal window after triggering, l is the length of the post-trigger delay signal window, d is the trigger duration.

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