Adaptively adjusted distributed fiber optic vibration sensor method, system and apparatus

Abstract

The application provides a self-adaptive adjustment distributed optical fiber vibration sensor method, system and device, which is applied to the field of optical fiber sensing technology and comprises the following steps: receiving parameters of a DVS, selecting a monitoring mode applied by self-adaptive adjustment according to the received parameters of the DVS, the monitoring mode comprising a full-line measurement mode and a local measurement mode, calculating average light intensity and interference coefficient of a preset reference optical fiber section, judging whether the average light intensity is within a preset range, if yes, judging whether the interference coefficient is within a preset range, if yes, demodulating and calculating a vibration signal and positioning information, matching state information and early warning information according to a preset algorithm model, and displaying the output state information and early warning information. The application adopts the DVS to adaptively adjust line parameters after the optical fiber is connected to realize the best monitoring effect, and the DVS is changed from professional and complex to simple and easy to use without complex debugging by professional technicians.

Description

Technical Field

[0001] This invention relates to the field of fiber optic sensing technology, and in particular to a method, system, and apparatus for adaptively adjusting distributed fiber optic vibration sensors. Background Technology

[0002] There are various technical solutions for fiber optic vibration sensing. Among them, the Distributed Fiber Vibration System (DVS) based on phase-sensitive optical time-domain reflectometry (Φ-OTDR) technology has been increasingly used in intrusion detection, perimeter security and infrastructure security monitoring based on communication optical fibers due to its advantages such as single-end, distributed, and high-precision positioning that only requires connection to a single-core optical fiber.

[0003] Generally, with other hardware remaining constant, the narrower the linewidth of the light source, the more pronounced the interference effect of the scattered light, and the higher the sensitivity of the system in detecting vibration signals. For a DVS system, the actual detection effect will vary due to factors such as the length and loss quality of the connected external detection fiber, the output power of the system light source, the pulse width, and the amplification performance of the detector. Regarding the output power of the light source, if the output is too weak, the cumulative loss at a distance on a fiber will be significant, resulting in only very weak Rayleigh scattering light, insufficient to guarantee good detection. However, if the output is too strong, it may cause nonlinear effects in the fiber (such as Brillouin scattering), degrading the detection effect, or the scattered light may exceed the detector's maximum receiving light intensity, causing saturation and rendering measurement impossible. Furthermore, for long-distance DVS, excessive light source output power may lead to light saturation at the beginning of the line, while insufficient power may result in poor signal at the end. In such cases, the power needs to be adjusted to a balanced value that covers the detector's dynamic range and satisfies the overall detection effect.

[0004] In actual detection, the parameters of DVS generally need to be adjusted to a relatively suitable value by technicians after confirming the signal status and application scenario and based on experience. If the status of the equipment or external line changes, the parameters need to be manually adjusted again. In order to achieve a better line vibration detection effect, it is often necessary to adjust the parameters repeatedly, which is a complex and technically challenging task. Summary of the Invention

[0005] The present invention aims to solve the problem that the parameters of the above-mentioned DVS generally need to be adjusted to a relatively suitable value by technicians, and when the status of the equipment or external line changes, multiple manual adjustments are required, which is complicated and technically difficult. The invention provides an adaptive adjustment distributed fiber optic vibration sensor system and method.

[0006] The present invention employs the following technical means to solve the technical problem:

[0007] This invention provides an adaptive adjustment method for a distributed fiber optic vibration sensor, comprising the following steps:

[0008] Receive parameters from DVS, including but not limited to detection distance and partition parameters;

[0009] The monitoring mode to be applied is selected based on the parameters of the received DVS, including full-line measurement mode and local measurement mode;

[0010] Calculate the average light intensity and interference coefficient of the preset reference fiber segment;

[0011] Determine whether the average light intensity is within the preset range;

[0012] If so, determine whether the interference coefficient is within the preset range;

[0013] If so, then demodulate and calculate the vibration signal and positioning information;

[0014] The status information and warning information are matched according to the preset algorithm model;

[0015] The output status information and warning information will be displayed.

[0016] Furthermore, the step of adaptively adjusting the selected monitoring mode based on the received DVS parameters further includes:

[0017] Power is supplied by driving the current source and voltage source using the drive circuit according to the selected mode and the received parameters;

[0018] A narrow-linewidth pulsed light source is generated by modulating a laser, or the continuous optical signal output by the laser is modulated into the required optical pulse using an acousto-optic modulator or an electro-optic modulator, wherein the pulse width is 10~500ns.

[0019] The generated narrow-linewidth pulse light source is collected.

[0020] Furthermore: the step of calculating the average light intensity and interference coefficient of the preset reference fiber segment includes:

[0021] The coherence coefficient υ of the Rayleigh scattering signal corresponding to a certain segment of optical fiber is calculated using the following formula:

[0022] in, It is the light intensity at the brightest point of the interference fringes. It is the light intensity at the darkest point of the interference fringes. The light intensity is set to a range of 0-1. Then, when... =0 and When υ = 1, it means there is no light in the dark areas and the light intensity in the bright areas is at its maximum. Simultaneously, when υ = 1, the fringe clarity is highest, indicating "perfect coherence"; when... When υ = I, the fringes are not visible; at this time, υ = 0, which is "completely incoherent"; when < When 0 < υ < 1, it is "partially coherent".

[0023] Furthermore, the step of calculating the average light intensity and interference coefficient of the preset reference fiber segment also includes:

[0024] If the scattered light from the entire optical fiber is divided into segments for calculation, the formula for calculating the coherence coefficient of the i-th segment is:

[0025]

[0026] The average value of all light intensity peaks in the i-th segment is denoted as . The average of all light intensity valley values ​​is denoted as The average value of all peak light intensities in segment i is denoted as and the average value of all valley light intensities is denoted as . , Let be the average coherence coefficient of the scattered light in the i-th fiber segment, with a value ranging from 0 to 1. This coefficient serves as the primary evaluation criterion for the system's detection sensitivity at this fiber segment. When evaluating the overall detection performance of the system at the i-th fiber segment, it should simultaneously satisfy… and Only then can it be judged as having a good effect, among which, The minimum threshold for the coherence coefficient to achieve a satisfactory detection effect. The minimum threshold of average light intensity required to achieve satisfactory detection results. The maximum average light intensity required to achieve a satisfactory detection effect.

[0027] Furthermore, the step of determining whether the average light intensity is within a preset range also includes:

[0028] If not, the drive circuit is invoked and controlled according to the selected mode and parameters, and adjustments are made by driving the narrow linewidth pulse light source, EDFA, and adjustable amplifier circuit.

[0029] Furthermore, the step of determining whether the interference coefficient is within a preset range if so, further includes:

[0030] If not, the drive circuit is invoked and controlled according to the selected mode and parameters, and adjustments are made by driving the narrow linewidth pulse light source, EDFA, and adjustable amplifier circuit.

[0031] Furthermore: Before the step of demodulating and calculating the vibration signal and positioning information, the method further includes:

[0032] The optical signal data is transmitted to the photodetector through a three-terminal optical ring converter;

[0033] Optical signal data is converted into electrical analog signals using a photodetector;

[0034] The analog signal is amplified by an adjustable amplifier circuit;

[0035] Convert analog electrical signals into digital signals;

[0036] Vibration signals and positioning information are calculated based on digital signals.

[0037] Furthermore, the step of transmitting optical signal data to the photodetector via a three-terminal optical ring converter further includes:

[0038] The optical signal data is input from the first port through a three-terminal optical ring converter;

[0039] The input optical signal data is output from the second port;

[0040] Optical signal data is transmitted to the communication optical fiber via a reference optical fiber, and backscattered Rayleigh light is generated during the transmission.

[0041] Backscattered Rayleigh light is transmitted through communication fiber and reference fiber, and is input from the second port of the three-terminal optical circulator and output from the third port.

[0042] This invention also provides an adaptively adjustable distributed fiber optic vibration sensor system, comprising: a display screen, a driving circuit, a laser, an acousto-optic modulator, an electro-optic modulator, a high-speed data acquisition module, a computing core, a narrow-linewidth pulsed light source, an EDFA, an adjustable amplifier circuit, a three-terminal optical circulator, a communication optical fiber, and a reference optical fiber, wherein...

[0043] The display screen is electrically connected to the computer processing core.

[0044] The computer processing core is electrically connected to the drive circuit and the high-speed data acquisition module, respectively.

[0045] The narrow linewidth pulsed light source is electrically connected to the driving circuit and the EDFA, respectively.

[0046] The three-terminal optical ring type is electrically connected to the EDFA, the photodetector and the reference optical fiber, respectively;

[0047] The adjustable amplifier circuit is electrically connected to the high-speed data acquisition module;

[0048] The reference optical fiber is electrically connected to the communication optical fiber.

[0049] This invention also provides an adaptively adjustable distributed fiber optic vibration sensor device, comprising:

[0050] The receiving module is used to receive parameters from the DVS.

[0051] The selection module is used to select the adaptive adjustment of the applied monitoring mode based on the parameters of the received DVS, the monitoring mode including full-line measurement mode and local measurement mode;

[0052] The calculation module is used to calculate the average light intensity and interference coefficient of the preset reference fiber segment;

[0053] The first judgment module is used to determine whether the average light intensity is within a preset range;

[0054] The second judgment module is used to determine whether the interference coefficient is within a preset range;

[0055] The processing module is used to demodulate and calculate vibration signals and positioning information;

[0056] The matching module is used to match status information and warning information according to a preset algorithm model.

[0057] This invention provides an adaptive adjustment method, system, and device for distributed fiber optic vibration sensors, which have the following advantages:

[0058] (1) The DVS used in this invention can adaptively adjust the line parameters after connecting the optical fiber to achieve the best monitoring effect. It does not require professional technicians to perform complex debugging, making the DVS simple and easy to use instead of professional and complex.

[0059] (2) The present invention adopts a dual mode of full-line monitoring and local monitoring. By flexibly selecting, it can carry out full-line online early warning monitoring, or make local adjustments to specific areas to achieve the best detection effect.

[0060] (3) The present invention adopts a local monitoring mode, which can monitor the dynamic range simultaneously without taking into account the front and rear sections of the long-distance line signal, thereby improving the actual dynamic range of the specific local monitoring location and having a better detection effect.

[0061] (4) The present invention adopts an adaptive adjustment distributed optical fiber vibration sensor system, which can be used not only for online monitoring and early warning of the entire DVS line, but also for fault location, route calibration, short-term local detection and maintenance of optical fiber lines, etc., greatly expanding the application scenarios and usage boundaries of DVS and improving the convenience of the application process. Attached Figure Description

[0062] Figure 1 This is a schematic diagram of the steps of an adaptive adjustment distributed optical fiber vibration sensor method in one embodiment of the present invention;

[0063] Figure 2This is a block diagram of an adaptively adjustable distributed fiber optic vibration sensor system according to an embodiment of the present invention.

[0064] Figure 3 This is a block diagram of an adaptively adjustable distributed optical fiber vibration sensor device according to an embodiment of the present invention.

[0065] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0066] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0067] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0068] Reference Appendix Figure 1 The adaptive adjustment distributed fiber optic vibration sensor method according to one embodiment of the present invention includes:

[0069] S1, Receive parameters from DVS, including but not limited to detection distance and partition parameters;

[0070] S2, Select the applicable monitoring mode for adaptive adjustment based on the parameters of the received DVS, wherein the monitoring mode includes full-line measurement mode and local measurement mode;

[0071] S3, calculate the average light intensity and interference coefficient of the 7 segments of the preset reference fiber;

[0072] S4, determine whether the average light intensity is within the preset range;

[0073] S5, if yes, then determine whether the interference coefficient is within the preset range;

[0074] S6, if so, then demodulate and calculate the vibration signal and positioning information;

[0075] S7, matches status information and warning information according to the preset algorithm model;

[0076] S8 displays the output status and warning information.

[0077] In the above steps, the user first inputs the DVS parameters on the preset display screen 1 and receives the DVS parameters. These parameters include, but are not limited to, the detection distance, zone parameters, and alarm-related parameters. In one specific embodiment, the input parameter is the detection distance, such as 5 meters. Then, based on the received DVS parameters, the system selects the adaptive adjustment monitoring mode. The monitoring modes include a full-line measurement mode and a local measurement mode. In one specific embodiment, when the full-line measurement mode is selected, the system adaptively adjusts the parameters to ensure that any area along the entire line is in a good detection state and has good early warning capabilities. In another specific embodiment, when the local measurement mode is selected, the system adaptively adjusts the parameters to ensure that the selected fiber optic line segment has the best detection state and early warning capabilities. After selecting the mode, the system calculates the average light intensity and interference coefficient of the preset reference fiber optic segment 7. If the calculated average light intensity is within a preset range, the system then determines whether the interference coefficient is within a preset range. If the calculated average light intensity is not within a preset range, then... The computer processing core calls the control drive circuit 3 according to the set mode and parameters. The drive circuit 3 drives the narrow linewidth pulse light source 4, EDFA, and adjustable amplifier circuit 10 to work, thereby amplifying or adjusting the pulse width of the light source, the power of the EDFA, and the amplifier circuit level until the calculated average light intensity is within the preset range. If the calculated interference coefficient is within the preset range, the vibration signal and positioning information are demodulated and calculated, and the output status information and warning information are displayed. If the calculation result does not meet the preset range, the computer processing core calls the control drive circuit 3 according to the set mode and parameters. The drive circuit 3 drives the narrow linewidth pulse light source 4, EDFA, and adjustable amplifier circuit 10 to work, thereby amplifying or adjusting the pulse width of the light source, the power of the EDFA, and the amplifier circuit level until the calculated interference coefficient is within the preset range. Then, the vibration signal and positioning information are demodulated and calculated again. The calculated vibration signal and positioning information are matched with the preset algorithm model. Then, the display module outputs and displays the corresponding status information and alarm information.

[0078] In one embodiment, the monitoring mode to be adaptively adjusted is selected based on the parameters of the received DVS, the monitoring mode including a full-line measurement mode and a local measurement mode.

[0079] In practical implementation, for the full-line detection mode, it is necessary to ensure good detection performance along the entire connected fiber optic cable. However, the tail section of the line suffers greater loss, requiring increased light intensity to improve the signal-to-noise ratio. But if the light intensity is too high, it can cause saturation of the detector or acquisition circuit, or nonlinear effects that distort the signal. Among these, the signal saturation nonlinear effect of the acquisition circuit manifests in the evaluation parameters as the signal strength exceeding the upper limit. Or the coherence coefficient is less than the threshold Therefore, the main adjustment goal of the full-line detection is to maximize the signal strength of the front-end section without saturation. Since the reference fiber 7 is equivalent to the frontmost part of the fiber optic line and is not affected by external interfaces or loss anomalies, the average calculated parameters of this fiber optic section are directly used as evaluation parameters. When the parameters do not meet the calculation formula of the coherence coefficient of the i-th section, the output parameters of the hardware are changed to make its average light intensity as close as possible to the upper limit value, so that any area of ​​the entire line is in a good detection state and has a good early warning capability. For the local detection mode, since the detection area has been selected, it is only necessary to calculate its average light intensity and average coherence coefficient and adjust the hardware output parameters to meet the detection effect requirements, regardless of the signal-to-noise ratio, saturation, or nonlinear effects of the unselected section. Since the local measurement mode does not need to ensure that the signal in the front-end area is not too strong, leading to detector saturation, and the signal in the back section is not too weak, leading to a decrease in detection effect, as the full-line measurement mode does not, it is not limited by the dynamic range of signal detection, and the detection capability can achieve the optimal effect, so that the selected fiber optic line section has the best detection state and early warning capability.

[0080] In this embodiment, the step of adaptively adjusting the selected monitoring mode based on the received DVS parameters further includes:

[0081] Power is supplied by driving current source and voltage source using drive circuit 3 according to the selected mode and received parameters;

[0082] A narrow-linewidth pulsed light source 4 is generated by triggering a laser, or the continuous optical signal output by the laser is modulated into the required optical pulse using an acousto-optic modulator or an electro-optic modulator, wherein the pulse width is 10~500ns.

[0083] The generated narrow-linewidth pulse light source 4 is collected.

[0084] In specific implementation, the drive circuit 3 directly controls and drives the current source and voltage source according to the set mode to supply power to each optoelectronic module in the system. Then, the laser is directly modulated and triggered to generate a narrow linewidth pulse light source 4, or the continuous light signal output by the laser is modulated into the required light pulse using an acousto-optic modulator or an electro-optic modulator. The narrow linewidth pulse light source 4 is an optical fiber vibration sensing light source with a narrow frequency width, which can be selected between 1kHz and 500kHz linewidth according to different applications. In one specific embodiment, the narrow linewidth pulse light source 4 is generated by direct modulation and triggering of the laser. In another specific embodiment, the continuous light signal output by the laser is modulated into the required light pulse using an acousto-optic modulator or an electro-optic modulator. The pulse width can be adjusted within the range of 10 to 500ns as needed. Finally, the data acquisition module collects the generated narrow linewidth pulse light source 4.

[0085] In this embodiment, the steps of calculating the average light intensity and interference coefficient of the seven segments of the preset reference fiber include:

[0086] The coherence coefficient υ of the Rayleigh scattering signal corresponding to a certain segment of optical fiber is calculated using the following formula:

[0087] in, It is the light intensity at the brightest point of the interference fringes. It is the light intensity at the darkest point of the interference fringes. The light intensity is set to a range of 0-1. Then, when... =0 and When υ=1, it means there is no light in the dark areas and the light intensity in the bright areas is at its maximum. Simultaneously, when υ=1, the fringe clarity is highest, indicating "perfect coherence." When υ = I, the fringes are not visible; at this time, υ = 0, which is "completely incoherent"; when < When 0 < υ < 1, it is "partially coherent".

[0088] In practical implementation, because DVS uses a narrow linewidth light source, backscattered Rayleigh light is generated in the optical fiber. This Rayleigh scattered light forms alternating bright and dark fringes. As partially coherent light, the higher the degree of coherence, the higher the visibility of the fringes, indicating a more realistic demodulated phase information and a higher sensitivity of the entire vibration sensing system. Therefore, the coherence coefficient υ of the Rayleigh scattered signal corresponding to a certain segment of optical fiber is used to calculate the clarity. The coherence coefficient is also called the visibility of the interference fringes. =0 and When υ=1, it means there is no light in the dark areas, and the light intensity in the bright areas is at its maximum. At the same time, when υ=1, the fringe clarity is the highest, indicating "complete coherence." When =I, the fringes are invisible and υ=0, indicating "complete incoherence". < When υ is in the range of 0 < υ < 1, it is "partially coherent".

[0089] In this embodiment, the step of calculating the average light intensity and interference coefficient of the seven segments of the preset reference fiber further includes:

[0090] If the scattered light from the entire optical fiber is divided into segments for calculation, the formula for calculating the coherence coefficient of the i-th segment is:

[0091]

[0092] The average value of all light intensity peaks in the i-th segment is denoted as . The average of all light intensity valley values ​​is denoted as The average value of all peak light intensities in segment i is denoted as and the average value of all valley light intensities is denoted as . , Let be the average coherence coefficient of the scattered light in the i-th fiber segment, with a value ranging from 0 to 1. This coefficient serves as the primary evaluation criterion for the system's detection sensitivity at this fiber segment. When evaluating the overall detection performance of the system at the i-th fiber segment, it should simultaneously satisfy… and Only then can it be judged as having a good effect, among which, The minimum threshold for the coherence coefficient to achieve a satisfactory detection effect. The minimum threshold of average light intensity required to achieve satisfactory detection results. The maximum average light intensity required to achieve a satisfactory detection effect.

[0093] In practical implementation, since the scattered light signal acquired by DVS includes the signal intensity corresponding to the entire length of the connecting optical fiber, it is only necessary to calculate the coherence coefficient υ of the scattered light to evaluate the detection sensitivity of the vibration sensor represented by the scattered light signal. Let be the average coherence coefficient of the scattered light in the i-th fiber segment, ranging from 0 to 1. This coefficient serves as the primary evaluation criterion for the system's detection sensitivity at this segment. Since the optical signal gradually weakens and its intensity decreases with increasing propagation distance in the fiber, the signal-to-noise ratio of the signal acquired at greater distances deteriorates, resulting in a decline in the sensing performance. Therefore, the average light intensity of the i-th fiber segment is calculated by averaging the light intensity signals from all data points in this segment. When evaluating the overall detection performance of the system at the i-th fiber segment, the following conditions must be met simultaneously: and Only when the light intensity is too high can a better effect be achieved. However, if the light intensity is too high, it will exceed the maximum input range of the photodetector 9 or the data acquisition circuit, leading to signal saturation. Therefore, both upper and lower limits should be present.

[0094] In this embodiment, the step of determining whether the average light intensity is within a preset range further includes:

[0095] If not, the drive circuit 3 is invoked and controlled according to the selected mode and parameters, and adjustments are made by driving the narrow linewidth pulse light source 4, EDFA and adjustable amplifier circuit 10.

[0096] In practical implementation, when the calculated average light intensity value of the reference fiber segment 7 is within the preset range, the average light intensity value is output. When the calculated average light intensity value does not meet the preset range, the light source pulse width, EDFA power, and amplifier circuit level are adjusted or amplified until the average light intensity value reaches the set range. The light source pulse width range can be adjusted between 10 and 500 ns as needed. First, the pulse signal light output by the narrow linewidth pulse light source 4 is amplified and adjusted using a pulsed EDFA until the adjusted average light intensity value reaches the set range. The EDFA is an erbium-doped fiber amplifier 5 and a pulsed EDFA is used.

[0097] In this embodiment, if so, the step of determining whether the interference coefficient is within a preset range further includes:

[0098] If not, the drive circuit 3 is invoked and controlled according to the selected mode and parameters, and adjustments are made by driving the narrow linewidth pulse light source 4, EDFA and adjustable amplifier circuit 10.

[0099] In practical implementation, the interference coefficient of the preset reference fiber 7 segment is calculated. When the interference coefficient is within the preset value range, the interference coefficient value is output. When the calculated interference coefficient is not within the preset value range, the light source pulse width, EDFA power, and amplifier circuit level are adjusted until the average light intensity value reaches the set range. The light source pulse width range can be adjusted between 10 and 500 ns as needed. First, the power of the pulse signal light output by the narrow linewidth pulse light source 4 is amplified and adjusted using a pulsed EDFA until the adjusted average light intensity value reaches the set range. Here, the EDFA is an erbium-doped fiber amplifier 5.

[0100] In this embodiment, before the step of demodulating and calculating the vibration signal and positioning information, the following steps are also included:

[0101] The optical signal data is transmitted to the photodetector 9 via the three-terminal optical ring 6;

[0102] The optical signal data is converted into an electrical analog signal by the photodetector 9;

[0103] The analog signal is amplified by the adjustable amplifier circuit 10;

[0104] Convert analog electrical signals into digital signals;

[0105] Vibration signals and positioning information are calculated based on digital signals.

[0106] In practical implementation, the optical signal data is transmitted through the three-terminal optical ring 6 and then enters the photodetector 9. The photodetector 9 converts the optical signal data into an electrical analog signal. The adjustable amplifier circuit 10 amplifies the electrical analog signal and then enters the high-speed data acquisition module 11 to convert the electrical analog signal into a digital signal. Then, the processing module calculates the vibration signal and the positioning signal based on the digital signal.

[0107] In this embodiment, the step of transmitting optical signal data to photodetector 9 via three-terminal optical circulator 6 further includes:

[0108] The optical signal data is input from the first port through the three-terminal optical ring converter 6;

[0109] The input optical signal data is output from the second port;

[0110] The optical signal data is transmitted to the communication optical fiber 8 via the reference optical fiber 7, and backscattered Rayleigh light is generated during the transmission.

[0111] Backscattered Rayleigh light is transmitted through communication fiber 8 and reference fiber 7, and is input from the second port of the three-terminal optical circulator 6 and output from the third port.

[0112] In practice, the optical signal data enters through the first port and is output through the second port. After being output, it enters the communication optical fiber 8 through the reference optical fiber 7. During the transmission process, the optical signal data generates backscattered Rayleigh light in the communication optical fiber 8, and enters through the second port through the communication optical fiber 8 and the reference optical fiber 7 in sequence. Then it is output from the third port and enters the detector.

[0113] In summary: In specific implementation, the user first inputs the DVS parameters on the preset display screen 1 and receives the DVS parameters, which include, but are not limited to, detection distance, zone parameters, and alarm-related parameters. In one specific embodiment, the input parameter is the detection distance, such as 5 meters. Then, based on the received DVS parameters, the system adaptively adjusts and selects the applicable monitoring mode. The monitoring modes include full-line measurement mode and local measurement mode. In one specific embodiment, when the full-line measurement mode is selected, the system adaptively adjusts the parameters to ensure that any area along the entire line is in a good detection state and has good early warning capabilities. In another specific embodiment, when the local measurement mode is selected, the system adaptively adjusts the parameters to ensure that the selected fiber optic line segment has the best detection state and early warning capabilities. After the mode selection is completed, the average light intensity and interference coefficient of the preset reference fiber optic segment 7 are calculated. If the calculated average light intensity is within the preset range, then it is determined whether the interference coefficient is within the preset range. If the calculated average light intensity is not within the preset range... The computer processing core calls the control drive circuit 3 according to the set mode and parameters. The drive circuit 3 drives the narrow linewidth pulse light source 4, EDFA, and adjustable amplifier circuit 10 to work, thereby amplifying or adjusting the pulse width of the light source, the power of the EDFA, and the amplifier circuit level until the calculated average light intensity is within the preset range. If the calculated interference coefficient is within the preset range, the vibration signal and positioning information are demodulated and calculated, and the output status information and warning information are displayed. If the calculation result does not meet the preset range, the computer processing core calls the control drive circuit 3 according to the set mode and parameters. The drive circuit 3 drives the narrow linewidth pulse light source 4, EDFA, and adjustable amplifier circuit 10 to work, thereby amplifying or adjusting the pulse width of the light source, the power of the EDFA, and the amplifier circuit level until the calculated interference coefficient is within the preset range. Then, the vibration signal and positioning information are demodulated and calculated again. The calculated vibration signal and positioning information are matched with the preset algorithm model. Then, the display module outputs and displays the corresponding status information and alarm information.

[0114] Reference Appendix Figure 3 An adaptively adjustable distributed fiber optic vibration sensor device includes:

[0115] The receiving module is used to receive parameters from the DVS.

[0116] The selection module is used to select the adaptive adjustment of the applied monitoring mode based on the parameters of the received DVS, the monitoring mode including full-line measurement mode and local measurement mode;

[0117] The calculation module is used to calculate the average light intensity and interference coefficient of the seven segments of the preset reference fiber;

[0118] The first judgment module is used to determine whether the average light intensity is within a preset range;

[0119] The second judgment module is used to determine whether the interference coefficient is within a preset range;

[0120] The processing module is used to demodulate and calculate vibration signals and positioning information;

[0121] The matching module is used to match status information and warning information according to a preset algorithm model.

[0122] In specific implementation, the receiving module is used to receive the parameters of DVS, the selection module is used to select the monitoring mode applied for adaptive adjustment according to the received DVS parameters, the monitoring mode includes full-line measurement mode and local measurement mode, the calculation module is used to calculate the average light intensity and interference coefficient of the 7 segments of the preset reference fiber, the first judgment module is used to determine whether the average light intensity is within the preset range, the second judgment module is used to determine whether the interference coefficient is within the preset range, the processing module is used to demodulate and calculate the vibration signal and positioning information, and the pairing module is used to match the status information and early warning information according to the preset algorithm model.

[0123] In summary: In practical implementation, the receiving module first receives the DVS parameters, then the selection module selects the monitoring mode to be applied for adaptive adjustment based on the received DVS parameters. The monitoring modes include full-line measurement mode and local measurement mode. The calculation module calculates the average light intensity and interference coefficient of the 7 segments of the preset reference fiber. The first judgment module judges whether the average light intensity is within the preset range, and the second judgment module judges whether the interference coefficient is within the preset range. The processing module demodulates and calculates the vibration signal and positioning information, and the pairing module matches the status information and early warning information according to the preset algorithm model.

[0124] Reference Appendix Figure 2 An adaptive distributed fiber optic vibration sensor system includes: a display screen 1, a drive circuit 3, a laser, an acousto-optic modulator, an electro-optic modulator, a high-speed data acquisition module 11, a computing core 2, a narrow-linewidth pulse light source 4, an EDFA 5, an adjustable amplifier circuit 10, a three-terminal optical circulator 6, a communication optical fiber 8, and a reference optical fiber 7. The display screen 1 is electrically connected to the computer processing core 2, which is electrically connected to the drive circuit 3 and the high-speed data acquisition module 11. The narrow-linewidth pulse light source 4 is electrically connected to the drive circuit 3 and the EDFA 5. The three-terminal optical circulator 6 is electrically connected to the EDFA 5, the photodetector 9, and the reference optical fiber 7. The adjustable amplifier circuit 10 is electrically connected to the high-speed data acquisition module 11, and the reference optical fiber 7 is electrically connected to the communication optical fiber 8.

[0125] In practical implementation, the driving circuit 3 powers the current source and voltage source according to the selected mode and input parameters, and drives the narrow-linewidth pulse light source 4, EDFA, and adjustable amplifier circuit 10 to operate. The laser triggers the generation of the narrow-linewidth pulse light source 4. The erbium-doped fiber amplifier 5 amplifies and adjusts the narrow-linewidth pulse light source 4. The erbium-doped fiber amplifier 5 uses a pulsed EDFA. The adjustable amplifier circuit 10 amplifies the electrical analog signal. The adjustable amplifier circuit 10 includes circuits with multiple amplification factors and an analog switch for switching amplification levels. The three-terminal optical ring 6 transmits the optical signal data. The photodetector 9 converts the optical signal data into an electrical analog signal. The photodetector 9 can... The optical signal data is transmitted using a PIN (photodiode) detector or an APD (avalanche diode) detector, a reference fiber 7 and a communication fiber 8. The computing and processing core 2 is used to call and control the drive circuit 3 according to the mode and parameters. The reference fiber 7 is a built-in single-mode communication fiber 8 with a length ranging from 20 to 100 meters. The reference fiber 7 and the communication fiber 8 are connected by fusion splicing or quick-connect flanges. The communication fiber 8 includes, but is not limited to, the communication fiber 8 of the actual line and the fiber optic for laboratory testing. The high-speed data acquisition module 11 includes an FPGA and an AD chip, which is used to convert electrical signals into digital signals with a sampling rate of 100MHz-1GHz.

[0126] In summary, the adaptive adjustment distributed fiber optic vibration sensor method, system, and device provided in this embodiment of the invention first inputs and sets the DVS parameters on the display screen 1. These parameters include, but are not limited to, the detection distance, zone parameters, and alarm-related parameters. Next, the receiving module receives the DVS parameters, and the selection module selects the monitoring mode applied for adaptive adjustment based on the received DVS parameters. The monitoring modes include full-line measurement mode and local measurement mode. After selecting the mode, the calculation module calculates the average light intensity and interference coefficient of the preset reference fiber segment 7. The first judgment module judges whether the calculated average light intensity is within a preset range. If the calculated average light intensity is within the preset range, it then judges whether the interference coefficient is within the preset range. If the calculated average light intensity is not within the preset range, the computer processing core calls the control drive circuit 3 according to the set mode and parameters. The drive circuit 3 drives the narrow-linewidth pulse light source 4, the EDFA, and the adjustable amplifier circuit 10 to operate, thereby amplifying or adjusting the light source pulse width, EDFA power, and amplifier circuit level until the calculated average light intensity is reached. Within a preset range, the second judgment module judges whether the result of the interference coefficient is within the preset range. If the calculated interference coefficient is within the preset range, the vibration signal and positioning information are demodulated and calculated, and the output status information and warning information are displayed. If the calculation result does not meet the preset range, the control drive circuit 3 is called according to the set mode and parameters. The drive circuit 3 drives the narrow linewidth pulse light source 4, EDFA and adjustable amplifier circuit 10 to work, thereby adjusting the light source pulse width, EDFA power and amplifier circuit level until the calculated interference coefficient is within the preset range. Then the processing module demodulates the calculated vibration signal and positioning information, and the pairing module matches the calculated vibration signal and positioning information with the preset algorithm model. During this process, the steps of continuously collecting full-line optical signal data, calculating the average light intensity and interference coefficient of the preset reference fiber 7 segment, judging whether the average light intensity is within the preset range, judging whether the interference coefficient is within the preset range, demodulating and calculating the vibration signal and positioning information, and matching the status information and warning information according to the preset algorithm model are continuously cycled. Finally, the display screen 1 outputs and displays the corresponding status information and alarm information.

[0127] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, apparatus, article, or method that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, apparatus, article, or method. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, apparatus, article, or method that includes that element.

[0128] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An adaptive adjustment method for distributed fiber optic vibration sensors, characterized in that, Includes the following steps: Receive parameters from DVS, including but not limited to detection distance and partition parameters; The monitoring mode to be applied is selected based on the parameters of the received DVS, including full-line measurement mode and local measurement mode; Calculate the average light intensity and interference coefficient of the preset reference fiber segment; Determine whether the average light intensity is within the preset range; If not, the drive circuit is invoked and controlled according to the selected mode and parameters, and adjustments are made by driving the narrow linewidth pulse light source, EDFA and adjustable amplifier circuit; If so, determine whether the interference coefficient is within the preset range; If not, the drive circuit is invoked and controlled according to the selected mode and parameters, and adjustments are made by driving the narrow linewidth pulse light source, EDFA and adjustable amplifier circuit; If so, then demodulate and calculate the vibration signal and positioning information; The status information and warning information are matched according to the preset algorithm model; The output status information and warning information will be displayed.

2. The adaptive adjustment distributed fiber optic vibration sensor method according to claim 1, characterized in that, The step of adaptively adjusting the selection of the applied monitoring mode based on the parameters of the received DVS further includes: Power is supplied by driving the current source and voltage source using the drive circuit according to the selected mode and the received parameters; A narrow-linewidth pulsed light source is generated by triggering a laser, or the continuous optical signal output by the laser is modulated into the required optical pulse using an acousto-optic modulator or an electro-optic modulator, wherein the pulse width is 10~500ns. The generated narrow-linewidth pulse light source is collected.

3. The adaptive adjustment distributed fiber optic vibration sensor method according to claim 1, characterized in that, The steps of calculating the average light intensity and interference coefficient of the preset reference fiber segment include: The coherence coefficient υ of the Rayleigh scattering signal corresponding to a certain segment of optical fiber is calculated using the following formula: in, It is the light intensity at the brightest point of the interference fringes. It is the light intensity at the darkest point of the interference fringes. The light intensity is set to a range of 0-1. Then, when... =0 and When υ = 1, it means there is no light in the dark areas and the light intensity in the bright areas is at its maximum. Simultaneously, when υ = 1, the fringe clarity is highest, indicating "perfect coherence"; when... When υ = I, the fringes are not visible; at this time, υ = 0, which is "completely incoherent"; when < When 0 < υ < 1, it is "partially coherent".

4. The adaptive adjustment distributed fiber optic vibration sensor method according to claim 1, characterized in that, The steps of calculating the average light intensity and interference coefficient of the preset reference fiber segment also include: If the scattered light from the entire optical fiber is divided into segments for calculation, the formula for calculating the coherence coefficient of the i-th segment is: The average value of all light intensity peaks in the i-th segment is denoted as . The average of all light intensity valley values ​​is denoted as The average value of all peak light intensities in segment i is denoted as and the average value of all valley light intensities is denoted as . , Let be the average coherence coefficient of the scattered light in the i-th fiber segment, with a value ranging from 0 to 1. This coefficient serves as the primary evaluation criterion for the system's detection sensitivity at this fiber segment. When evaluating the overall detection performance of the system at the i-th fiber segment, it should simultaneously satisfy… and Only then can it be judged as having a good effect, among which, The minimum threshold for the coherence coefficient to achieve a satisfactory detection effect. The minimum threshold of average light intensity required to achieve satisfactory detection results. The maximum average light intensity required to achieve a satisfactory detection effect.

5. The adaptive adjustment distributed fiber optic vibration sensor method according to claim 1, characterized in that, The step of determining whether the average light intensity is within a preset range further includes: If not, the drive circuit is invoked and controlled according to the selected mode and parameters, and adjustments are made by driving the narrow linewidth pulse light source, EDFA, and adjustable amplifier circuit.

6. The adaptive adjustment method for a distributed fiber optic vibration sensor according to claim 1, characterized in that, If so, the step of determining whether the interference coefficient is within a preset range further includes: If not, the drive circuit is invoked and controlled according to the selected mode and parameters, and adjustments are made by driving the narrow linewidth pulse light source, EDFA, and adjustable amplifier circuit.

7. The adaptive adjustment distributed fiber optic vibration sensor method according to claim 1, characterized in that, Before the step of demodulating and calculating the vibration signal and positioning information, the method further includes: The optical signal data is transmitted to the photodetector through a three-terminal optical ring converter; Optical signal data is converted into electrical analog signals using a photodetector; The analog signal is amplified by an adjustable amplifier circuit; Convert analog electrical signals into digital signals; Vibration signals and positioning information are calculated based on digital signals.

8. The adaptive adjustment method for a distributed fiber optic vibration sensor according to claim 7, characterized in that, The step of transmitting optical signal data to the photodetector via a three-terminal optical ring converter further includes: The optical signal data is input from the first port through a three-terminal optical ring converter; The input optical signal data is output from the second port; Optical signal data is transmitted to the communication optical fiber via a reference optical fiber, and backscattered Rayleigh light is generated during the transmission. Backscattered Rayleigh light is transmitted through communication fiber and reference fiber, and is input from the second port of the three-terminal optical circulator and output from the third port.

9. An adaptively adjustable distributed fiber optic vibration sensor device, applied to the adaptively adjustable distributed fiber optic vibration sensor method according to any one of claims 1-8, characterized in that, include: The receiving module is used to receive parameters from the DVS. The selection module is used to select the adaptive adjustment of the applied monitoring mode based on the parameters of the received DVS, the monitoring mode including full-line measurement mode and local measurement mode; The calculation module is used to calculate the average light intensity and interference coefficient of the preset reference fiber segment; The first judgment module is used to determine whether the average light intensity is within a preset range; The second judgment module is used to determine whether the interference coefficient is within a preset range; The processing module is used to demodulate and calculate vibration signals and positioning information; The matching module is used to match status information and warning information according to a preset algorithm model.

10. An adaptively adjustable distributed fiber optic vibration sensor system, applied to the adaptively adjustable distributed fiber optic vibration sensor method according to any one of claims 1-8, characterized in that, include: Display screen, driver circuit, laser, acousto-optic modulator, electro-optic modulator, high-speed data acquisition module, computing core, narrow linewidth pulsed light source, EDFA, adjustable amplifier circuit, three-terminal optical circulator, communication optical fiber and reference optical fiber, among which, The display screen is electrically connected to the computer processing core. The computer processing core is electrically connected to the drive circuit and the high-speed data acquisition module, respectively. The narrow linewidth pulsed light source is electrically connected to the driving circuit and the EDFA, respectively. The three-terminal optical ring type is electrically connected to the EDFA, the photodetector and the reference optical fiber, respectively; The adjustable amplifier circuit is electrically connected to the high-speed data acquisition module; The reference optical fiber is electrically connected to the communication optical fiber.

Images