An optical cable routing census method and device based on optical fiber vibration sensing

Abstract

The present invention relates to the technical field of optical cable route census, and discloses an optical cable route census method and device based on fiber optic vibration sensing. The method includes: knocking at the optical cable stake points, and remotely controlling a pulsed light source to send optical pulses to the optical cable; collecting the vibration signals of the optical fiber, and dynamically adjusting the pulse width of the optical pulses; identifying the knocking events in the vibration signals, and intercepting the knocking vibration segments from the vibration signals; calculating the characteristic parameters of the knocking vibration segments, and performing knocking feedback based on the characteristic parameters; calculating the length of the optical cable at the optical cable stake points, and recording the longitude and latitude coordinates of the optical cable stake points; determining the optical cable direction at the optical cable stake points through knocking, and drawing the route map of the optical cable based on the longitude and latitude coordinates, optical cable length, and optical cable direction of the optical cable stake points. The present invention improves the census efficiency of the optical cable route, realizes the automatic drawing and intuitive display of the optical cable route, and facilitates the management and maintenance of the optical cable network.

Description

Technical Field

[0001] The present invention relates to the technical field of optical cable route census, and specifically relates to a method and device for optical cable route census based on fiber optic vibration sensing. Background Art

[0002] In traditional optical cable route census work, it mainly relies on manual on-site investigation and some simple testing equipment. Early methods usually involved construction workers conducting on-site visits along possible optical cable paths to check optical cable markings and related facilities. However, this method is extremely inefficient, especially in the case of long distances and complex terrains, which requires a large amount of human and time costs. In recent years, some testing equipment based on electrical principles has emerged, such as using a similar principle of a cable fault tester to detect optical cables. However, these devices have many limitations when applied to optical cables. On the one hand, the electrical testing method is easily affected by external electromagnetic interference, resulting in inaccurate test results. On the other hand, the electrical testing equipment has low detection sensitivity for some minor faults and potential problems of optical cables, and it is difficult to meet the requirements of high-precision detection of optical cables in modern communication.

[0003] In terms of optical cable route positioning, the existing technical means also have obvious deficiencies. When traditional methods determine the direction of an optical cable, they often lack precise positioning means. For example, in a complex underground pipe network environment where optical cables are intertwined with other pipelines, relying solely on manual experience and simple markings to judge the direction of the optical cable is prone to deviation. Moreover, when the burial depth of the optical cable is relatively deep or the surrounding environment changes (such as soil settlement, construction disturbance, etc.), it is difficult for traditional positioning methods to accurately determine the actual position of the optical cable, increasing the difficulty of optical cable maintenance and fault troubleshooting. In the field of optical cable vibration detection, although there are some studies and applications of fiber optic vibration sensors, there are still many problems in actual optical cable route census. Existing fiber optic vibration sensors have weak signal recognition ability in the face of complex environmental noise. For example, in environments such as strong winds and near busy roads, the noise generated by environmental vibrations will mask the vibration signal of the optical cable itself, making it difficult to effectively conduct optical cable route census based on vibration detection. In addition, the analysis and processing of vibration signals are not fine enough to accurately extract key characteristic parameters that can reflect the state and route information of the optical cable, resulting in inaccurate and unreliable judgment of the optical cable route.

[0004] In summary, the existing optical cable route census technologies have many defects in terms of efficiency, accuracy, anti-interference ability, and fineness, and it is difficult to meet the rapid development needs of the modern communication industry. New technological breakthroughs are needed to solve these problems.

[0005] A Chinese patent application with the publication number CN118890094A discloses an optical cable census instrument, an optical cable census method, and a system. The optical cable census instrument includes a vibration sensing module, a signal amplification circuit, a controllable switch module, a signal detection circuit, and an optical fiber interface connected to the sensing end of the vibration sensing module. The signal interfaces of the vibration sensing module are electrically connected to the signal detection circuit through the signal amplification circuit and the controllable switch module respectively. The signal detection circuit is used to determine the vibration state information of the optical cable to be surveyed at the target routing node based on the optoelectronic detection signal, and the controllable switch module is used to control the electrical connection between the signal amplification circuit and the signal detection circuit. By controlling the on-off of the controllable switch module, this application can not only ensure the accuracy of the optical cable census result, but also identify the optical cable connected to the optical cable census instrument from multiple optical cables to be surveyed, simplifying the identity confirmation process.

[0006] A Chinese patent application with the publication number CN117579138A discloses an intelligent optical cable routing census instrument, which includes a device host, a fiber to be measured, and a vibration motor; the device host is connected to the fiber to be measured, the fiber to be measured is laid dispersedly, and the vibration motor is placed on one side of the fiber to be measured after laying. The vibration motor is used to generate a vibration frequency that affects the transmission of the fiber to be measured. A laser is set in the device host, and the laser is connected to the fiber to be measured. The laser is used to transmit an optical signal 1 into the fiber to be measured. The optical signal 1 is transmitted in the fiber to be measured and is affected by the vibration frequency generated by the vibration motor to form an optical signal 2. An OTDR detection module and a vibration detection module are used to demodulate the optical signal 2 transmitted by the fiber to be measured and obtain data results, and the data results include the break point position and the direction of the fiber to be measured; the mobile terminal is used to receive and view the data results transmitted by the device host. This invention has the effects of determining the break point position and reducing human resources.

[0007] The above patent applications all have the problems raised in this background technology: when facing complex environmental noise, the signal recognition ability is weak.

[0008] The information disclosed in this background technology section is only intended to increase the understanding of the overall background of the present invention, and should not be regarded as an admission or any form of suggestion that this information constitutes the prior art already known to those of ordinary skill in the art. Summary of the Invention

[0009] The technical problem to be solved by the present invention is to overcome the defects of the prior art, and provide an optical cable routing census method and device based on fiber optic vibration sensing, which improve the census efficiency of the optical cable routing and realize the automatic drawing and intuitive display of the optical cable routing.

[0010] To solve the above technical problems, the present invention provides the following technical solutions:

[0011] On the one hand, the present invention provides a method for general survey of optical cable routes based on optical fiber vibration sensing, comprising the following steps:

[0012] S1: Knock at the optical cable pile points and remotely control a pulsed light source to send optical pulses to the optical cable;

[0013] S2: Collect the vibration signals of the optical fiber and dynamically adjust the pulse width of the optical pulses based on the vibration parameters of the vibration signals;

[0014] S3: Identify the knocking events in the vibration signals and intercept the knocking vibration segments from the vibration signals; the knocking vibration segments are the segments of the vibration signals corresponding to the knocking events;

[0015] S4: Calculate the characteristic parameters of the knocking vibration segments and perform knocking feedback based on the characteristic parameters;

[0016] S5: Calculate the optical cable length of the optical cable pile points based on the knocking vibration segments and record the longitude and latitude coordinates of the optical cable pile points;

[0017] S6: Determine the optical cable orientation of the optical cable pile points by knocking and draw a route map of the optical cable based on the longitude and latitude coordinates, optical cable length, and optical cable orientation of the optical cable pile points.

[0018] As a preferred solution of the method for general survey of optical cable routes based on optical fiber vibration sensing according to the present invention, wherein: the vibration signals of the optical fiber are backward Rayleigh scattering signals of the optical pulses;

[0019] The vibration parameters of the vibration signals include amplitude parameters and frequency parameters; the calculation method of the vibration parameters is as follows: filter and denoise the vibration signals; uniformly sample the vibration signals to obtain the amplitudes of N sampling points; calculate the mean value of the amplitudes of the N sampling points as the amplitude parameter; perform frequency domain transformation on the vibration signals and extract the peak frequency of the vibration signals as the frequency parameter.

[0020] As a preferred solution of the method for general survey of optical cable routes based on optical fiber vibration sensing according to the present invention, wherein: the method for dynamically adjusting the pulse width of the optical pulses is as follows:

[0021] Set the amplitude threshold and frequency threshold of the vibration signals; calculate the adjustment amount of the pulse width;

[0022] Set the maximum value of the pulse width, denoted as ; Set the minimum value of the pulse width, denoted as ; Adjust the pulse width, and the formula is as follows:

[0023] ;

[0024] Among them, w represents the pulse width after the optical pulse is adjusted; represents the initial value of the pulse width, represents the adjustment amount of the pulse width; if w is greater than , then the pulse width is set to ; if w is less than , then the pulse width is set to .

[0025] As a preferred solution of the optical cable routing census method based on optical fiber vibration sensing according to the present invention, wherein: the calculation formula of the adjustment amount of the pulse width is as follows:

[0026] ;

[0027] Among them, represents the adjustment amount of the pulse width; A represents the amplitude parameter; represents the amplitude threshold; f represents the frequency parameter; represents the frequency threshold; represents the first adjustment factor. When the amplitude parameter A is greater than the amplitude threshold , takes a value of 1. Otherwise, takes a value of 0; represents the second adjustment factor. When the frequency parameter f is greater than the frequency threshold , takes a value of 1. Otherwise, takes a value of 0; represents the weight coefficient of the amplitude parameter, represents the weight coefficient of the frequency parameter.

[0028] As a preferred solution of the optical cable routing census method based on optical fiber vibration sensing according to the present invention, wherein: the characteristic parameters of the knocking vibration segment include average amplitude, instability, and attenuation speed;

[0029] The average amplitude of the optical cable pile point is denoted as , which is the mean value of the amplitudes of the knocking vibration segment; the instability is denoted as , which is the standard deviation of the amplitudes of the knocking vibration segment; the attenuation speed is denoted as , and the calculation method is as follows:

[0030] Select two observation points on the same side of the optical cable pile point on the optical cable, denoted as P and Q respectively; among them, the distance between point P and the optical cable pile point is , and the distance between point Q and the optical cable pile point is , and is greater than ;

[0031] Locate points P and Q in the vibration signal, and record the amplitude at point P, denoted as ; record the amplitude at point Q, denoted as ;

[0032] Calculate the attenuation rate, and the formula is as follows:

[0033] .

[0034] As a preferred solution of the optical cable routing census method based on fiber optic vibration sensing according to the present invention, wherein: the tapping feedback includes tapping position feedback and tapping force feedback;

[0035] The tapping position feedback is specifically as follows:

[0036] Set the attenuation rate threshold, denoted as ; if the attenuation rate is greater than , then feedback a prompt to change the tapping position;

[0037] The tapping force feedback is specifically as follows:

[0038] Set the minimum threshold of the average amplitude, denoted as ; set the maximum threshold of the average amplitude, denoted as ; set the instability threshold, denoted as ;

[0039] If the average amplitude is less than , and the attenuation rate is not greater than , then feedback a prompt to increase the tapping force;

[0040] If the average amplitude is greater than , and the instability is greater than , then feedback a prompt to decrease the tapping force.

[0041] As a preferred solution of the optical cable routing census method based on fiber optic vibration sensing according to the present invention, wherein: the characteristic parameters of the tapping vibration segment further include the vibration frequency ratio; the vibration frequency ratio is denoted as , and the calculation method is as follows: perform spectral analysis on the tapping vibration segment to extract the peak frequency; the vibration frequency ratio is the ratio of the average amplitude to the peak frequency;

[0042] The tapping feedback further includes tapping frequency feedback, specifically as follows:

[0043] Set the minimum threshold of the vibration frequency ratio, denoted as ; Set the maximum threshold of the vibration frequency ratio, denoted as ; If the vibration frequency ratio is less than , then give a prompt to reduce the knocking frequency;

[0044] If the vibration frequency ratio is greater than , then give a prompt to increase the knocking frequency.

[0045] As a preferred solution of the optical cable route census method based on fiber optic vibration sensing described in the present invention, wherein: the method for determining the optical cable route by knocking at the optical cable pile points is as follows:

[0046] Taking the optical cable pile point as the center, select test points within a range with a radius of R;

[0047] Knock at each test point and extract the knocking vibration segment corresponding to each test point based on the vibration signal;

[0048] Calculate the average amplitude and frequency of the knocking vibration segment corresponding to each test point;

[0049] Calculate the deviation degree of each test point from the optical cable pile point; Mark the test point with the smallest deviation degree from the optical cable pile point as the route point; The calculation formula of the deviation degree is as follows:

[0050] ;

[0051] Wherein, g represents the deviation degree of any test point from the optical cable pile point; represents the average amplitude of any test point; represents the main frequency of any test point; represents the frequency of the optical cable pile point;

[0052] Calculate the optical cable length of the route point and record the longitude and latitude coordinates of the route point;

[0053] Determine the optical cable route of the optical cable pile point based on the optical cable length of the optical cable pile point and the optical cable length of the route point.

[0054] As a preferred solution of the optical cable route census method based on fiber optic vibration sensing described in the present invention, wherein: the longitude and latitude coordinates of the optical cable pile point are obtained through a mobile terminal held by the construction personnel and including a GPS positioning module; the optical cable length of the optical cable pile point is the length of the optical cable section between the optical cable pile point and the transmitting end; the transmitting end is the optical cable port where the pulsed light source sends optical pulses to the optical cable; the optical cable length of the route point is the length of the optical cable section between the route point and the transmitting end;

[0055] The method for determining the optical cable routing of the optical cable stake point based on the optical cable length of the optical cable stake point and the optical cable length of the routing point is as follows: If the optical cable length of the optical cable stake point is greater than the optical cable length of the routing point, the optical cable routing of the optical cable stake point is from the routing point to the optical cable stake point; if the optical cable length of the optical cable stake point is less than the optical cable length of the routing point, the optical cable routing of the optical cable stake point is from the optical cable stake point to the routing point.

[0056] In a second aspect, the present invention provides an optical cable routing census device based on fiber optic vibration sensing, including a pulsed light source, a fiber optic vibration sensor, a data processing module, a data storage module, and an intelligent mobile terminal; wherein:

[0057] The pulsed light source is used to send optical pulses to the optical cable; the pulsed light source adjusts the pulse width sent to the optical cable based on the adjustment instruction of the data processing module.

[0058] The fiber optic vibration sensor is used to collect the vibration signals of the optical fiber, identify the knocking events in the vibration signals, and intercept the knocking vibration segments.

[0059] The data processing module is used to calculate the adjustment amount of the pulse width and send an instruction to adjust the pulse width to the pulsed light source; the data processing module is also used to calculate the characteristic parameters of the knocking vibration segments and send corresponding prompts for knocking feedback to the mobile intelligent terminal.

[0060] The data storage module is used to store the relevant information of the optical cable stake points, including longitude and latitude coordinates, optical cable length, optical cable routing, optical cable number, stake point type, and stake point name.

[0061] The intelligent mobile terminal is used to remotely control the turning on of the pulsed light source and receive the corresponding prompts for knocking feedback; the intelligent mobile terminal is also used to obtain the longitude and latitude coordinates of the optical cable stake points; the intelligent mobile terminal also includes GIS software for drawing and displaying the optical cable routing map.

[0062] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0063] The present invention improves the census efficiency of the optical cable routing. Construction workers can use a portable mobile terminal to knock at the optical cable stake points and remotely control the pulsed light source to send optical pulses alone, and the optical cable routing census can be completed without the cooperation of multiple people, greatly saving labor and time costs. The pulse width of the optical pulse is dynamically adjusted based on the amplitude parameter and frequency parameter of the vibration signal, so as to collect more comprehensive and accurate vibration information, and at the same time avoid signal overlap and confusion.

[0064] Based on the characteristic parameters of the knocking vibration segments, the feedback of the knocking position, knocking force, and knocking frequency can be accurately given, which is convenient for construction personnel to adjust the knocking method in a timely manner to ensure the quality of the vibration signal. By determining the cable route and combining information such as longitude and latitude coordinates to draw the cable route map, the accuracy and integrity of the cable route census are improved. Store various detailed information of the cable stake points and import them into the geographic information system to achieve automatic drawing and intuitive display of the cable route, facilitating the management and maintenance of the cable network. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts. Among them:

[0066] Figure 1 It is a flowchart of a method for cable route census based on fiber optic vibration sensing provided by the present invention;

[0067] Figure 2 It is a flowchart of a method for determining the cable route of a cable stake point by knocking provided by the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0068] The technical solutions of the present invention will be described in detail below through the drawings and specific embodiments. It should be understood that the embodiments of the present invention and the specific features in the embodiments are detailed descriptions of the technical solutions of the present invention, rather than limitations on the technical solutions of the present invention. Without conflict, the technical features in the embodiments of the present invention and the embodiments can be combined with each other.

[0069] Embodiment 1

[0070] This embodiment introduces a method for cable route census based on fiber optic vibration sensing. Referring to Figure 1 , the method includes the following steps:

[0071] S1: Knock at the cable stake point and remotely control the pulsed light source to send optical pulses to the cable;

[0072] The construction personnel knock at the stake points where the target cable may exist, such as knocking on the manhole cover of the cable handhole. At the same time, remotely send instructions to turn on the pulsed light source, which can realize the vibration sensing test of the cable by a single person using a portable mobile terminal (such as a smart phone). Thus, the cable route census can be completed without the cooperation of multiple people, greatly improving the efficiency of the cable route census.

[0073] S2: Collect the vibration signal of the optical fiber and dynamically adjust the pulse width of the optical pulse based on the vibration parameters of the vibration signal;

[0074] The vibration signal of the optical fiber is the backward Rayleigh scattering signal of the optical pulse; an optical filter can be used to separate the backward Rayleigh scattering signal. For example, through a band-pass filter or a notch filter, according to the wavelength range of the Rayleigh scattering signal and the wavelengths of other possible interfering optical signals (such as Raman scattering optical signals, etc.), the Rayleigh scattering optical signal is screened out from the mixed optical signals. The central wavelength of the Rayleigh scattering signal is basically the same as the wavelength of the light pulse of the light source. By setting the filter bandwidth near this wavelength, the Rayleigh scattering optical signal can be selectively allowed to pass through while blocking the optical signals of other wavelengths.

[0075] The vibration parameters of the vibration signal include an amplitude parameter and a frequency parameter; the calculation method of the vibration parameters is as follows: filter and denoise the vibration signal; uniformly sample the vibration signal to obtain the amplitudes of N sampling points; calculate the mean value of the amplitudes of the N sampling points as the amplitude parameter; perform a frequency-domain transformation on the vibration signal and extract the peak frequency of the vibration signal as the frequency parameter.

[0076] The method for dynamically adjusting the pulse width of the optical pulse is as follows:

[0077] Set the amplitude threshold and frequency threshold of the vibration signal; calculate the adjustment amount of the pulse width, and the formula is as follows:

[0078] ;

[0079] Where, represents the adjustment amount of the pulse width; A represents the amplitude parameter; represents the amplitude threshold; f represents the frequency parameter; represents the frequency threshold; represents the first adjustment factor. When the amplitude parameter A is greater than the amplitude threshold , takes the value of 1. Otherwise, takes the value of 0; represents the second adjustment factor. When the frequency parameter f is greater than the frequency threshold , takes the value of 1. Otherwise, takes the value of 0; represents the weight coefficient of the amplitude parameter, represents the weight coefficient of the frequency parameter, both of which are set by those skilled in the art based on actual needs.

[0080] Set the maximum value of the pulse width, denoted as ; Set the minimum value of the pulse width, denoted as ; Adjust the pulse width, and the formula is as follows:

[0081] ;

[0082] Among them, w represents the pulse width after the optical pulse is adjusted; represents the initial value of the pulse width; if w is greater than , then set the pulse width to ; if w is less than , then set the pulse width to .

[0083] When the amplitude parameter of the vibration signal is greater than the amplitude threshold, it means that the optical fiber vibration is relatively intense. In this case, the pulse width can be appropriately increased. Because a larger vibration amplitude may cause the scattering and reflection of the optical signal in the optical fiber to be more complex. Increasing the pulse width can allow the optical pulse to have more time to interact with the vibration area in the optical fiber, so as to collect more comprehensive vibration information. For the vibration frequency, if the frequency parameter is higher than the frequency threshold, it means that the vibration changes rapidly. At this time, the pulse width can be appropriately reduced. High-frequency vibration will cause the optical signal to change multiple times in a short time. A narrower pulse width can capture these rapidly changing vibration signals more timely, avoiding signal overlap and confusion. At the same time, in order to avoid excessive adjustment, set the adjustment limit of the pulse width so that the adjustment of the pulse width is limited within a reasonable range.

[0084] S3: Identify the knocking event in the vibration signal and intercept the knocking vibration segment from the vibration signal; the knocking vibration segment is the segment of the vibration signal corresponding to the knocking event;

[0085] The vibration signal, that is, the backscattered Rayleigh signal, will gradually weaken with the increase of the optical fiber length under normal circumstances, showing a relatively smooth attenuation trend. When the optical fiber is not knocked, the vibration signal is relatively stable, and there may be some small fluctuations, which are mainly caused by factors such as environmental background noise and weak natural vibration of the optical fiber (such as micro-vibration of the optical fiber caused by temperature change and tiny air flow). When a knock occurs, an obvious fluctuation area will appear in the vibration signal. This fluctuation area corresponds to the knocking event, and its characteristic is that the signal amplitude will suddenly increase and then show complex changes within a period of time, including the fluctuation of the signal amplitude and possible frequency changes. By analyzing the area where the vibration signal deviates from the normal attenuation trend, the signal change range related to the knock can be determined. The time interval corresponding to this change range contains the information of the knocking point position.

[0086] S4: Calculate the characteristic parameters of the knocking vibration segment and perform knocking feedback based on the characteristic parameters;

[0087] The characteristic parameters of the tapping vibration segment include average amplitude, vibration frequency ratio, instability, and attenuation rate;

[0088] The average amplitude of the optical cable pile point is denoted as , which is the mean value of the amplitudes of the tapping vibration segment; The average amplitude shows whether the vibration signal is strong enough to ensure accurate perception and analysis. If the signal strength is too weak, it may not be possible to effectively extract characteristic information, affecting the calculation of the optical cable routing location and other parameters. The instability is denoted as , which is the standard deviation of the amplitudes of the tapping vibration segment; The instability can measure the fluctuation of the vibration signal. If the fluctuation is too large, it may indicate unstable tapping or other interferences. A stable vibration signal helps to improve the accuracy of data processing and analysis. The vibration frequency ratio is denoted as , and the calculation method is as follows: Perform spectral analysis on the tapping vibration segment to extract the peak frequency; The vibration frequency ratio is the ratio of the average amplitude to the peak frequency; The vibration frequency ratio can provide a comprehensive index for judging whether the current vibration state is within an optimal balance range. For example, if the amplitude is too large and the frequency is too low, it may cause excessive strain on the optical fiber, or if the frequency is too high and the amplitude is too small, the signal is difficult to detect.

[0089] The attenuation rate is denoted as , and the calculation method is as follows:

[0090] Select two observation points on the same side of the optical cable pile point on the optical cable, denoted as P and Q respectively; Among them, the distance between point P and the optical cable pile point is , and the distance between point Q and the optical cable pile point is , and is greater than ;

[0091] Locate points P and Q in the vibration signal and record the amplitude at point P, denoted as ; Record the amplitude at point Q, denoted as ;

[0092] Calculate the attenuation rate, and the formula is as follows:

[0093] .

[0094] When a tapping event occurs, an external force is applied to the optical fiber, causing the optical fiber to vibrate. After the tapping event ends, due to the elastic and damping characteristics of the optical fiber itself, the vibration will gradually decay, and the attenuation rate reflects the attenuation of the vibration signal during propagation in the optical cable. Excessive attenuation may affect the detectability and accuracy of the signal, especially in long-distance optical cable lines.

[0095] The tapping feedback includes tapping position feedback, tapping force feedback, and tapping frequency feedback;

[0096] The tapping position feedback is as follows:

[0097] Set the decay speed threshold, denoted as ; If the decay speed is greater than , then feedback a prompt to change the tapping position;

[0098] When the decay speed is too fast, it probably means that the tapping position is too far from the optical cable to effectively vibrate the optical cable, or there is an interference source near the tapping position, making the vibration signal unable to be transmitted normally. At this time, send a prompt to change the tapping position to the mobile terminal and provide suggestions for a more suitable tapping position, such as near the optical cable joint, etc.

[0099] The tapping force feedback is as follows:

[0100] Set the minimum threshold of the average amplitude, denoted as ; Set the maximum threshold of the average amplitude, denoted as ; Set the instability threshold, denoted as ;

[0101] If the average amplitude is less than , and the decay speed is not greater than , then feedback a prompt to increase the tapping force;

[0102] If the average amplitude is greater than , and the instability is greater than , then feedback a prompt to decrease the tapping force;

[0103] When signal strength analysis shows that the amplitude of the vibration signal is too low and the signal decay is normal, it may be caused by insufficient tapping force. For example, in a low-temperature environment, the elasticity of the optical fiber changes, and a greater tapping force is required to generate a strong enough vibration signal. If the signal strength is too high and unstable, it may be caused by too much tapping force. Excessive tapping force may generate too much noise interference and affect the accuracy of the signal.

[0104] The tapping frequency feedback is as follows:

[0105] Set the minimum threshold of the vibration frequency ratio, denoted as ; Set the maximum threshold of the vibration frequency ratio, denoted as ; If the vibration frequency ratio is less than , a prompt for reducing the tapping frequency is fed back; at this time, it may be due to too high a tapping frequency, resulting in insufficient time for the optical fiber to generate a large amplitude. At this time, reduce the tapping frequency to make the vibration frequency ratio approach the ideal range, thereby optimizing the signal quality.

[0106] If the vibration frequency ratio is greater than , a prompt for increasing the tapping frequency is fed back; at this time, it may be due to too low a tapping frequency, resulting in the inability to transfer the energy of the optical fiber vibration in time, causing the amplitude to accumulate to a large value. Increasing the tapping frequency can make the ratio of amplitude to frequency more reasonable.

[0107] Based on the feedback of the vibration signal, dynamically adjusting the tapping parameters can ensure that the vibration signal contains sufficient and accurate information. For example, in an environment with a low temperature, the elasticity of the optical fiber may change, and the tapping force should be appropriately increased to ensure the generation of sufficient vibration signals; for different optical cable models, due to their different internal structures and materials, different tapping frequencies may be required to better excite the vibration signal. Whether it is studying the basic vibration characteristics of optical fibers in the laboratory or in an actual optical fiber monitoring system (such as optical fiber communication line fault monitoring, optical fiber sensor applications, etc.), the vibration frequency ratio can be well applied. As long as the upper and lower limits of the vibration frequency ratio are reasonably set, the tapping frequency can be effectively adjusted to obtain a Rayleigh scattering signal with better quality.

[0108] S5: Calculate the optical cable length of the optical cable stake point based on the tapping vibration segment, and record the longitude and latitude coordinates of the optical cable stake point;

[0109] The longitude and latitude coordinates of the optical cable stake point are obtained through a mobile terminal held by the construction personnel and containing a GPS positioning module; the optical cable length of the optical cable stake point is the length of the optical cable segment between the optical cable stake point and the transmitting end; the transmitting end is the optical cable port where the pulsed light source sends optical pulses to the optical cable.

[0110] Record the time when the tapping vibration segment appears. Combining the propagation speed of the optical signal in the optical fiber, the propagation distance length of the optical signal can be obtained by multiplying the time by the speed, that is, the length of the optical cable segment between the optical cable stake point and the transmitting end.

[0111] S6: Determine the optical cable routing direction of the optical cable stake point through tapping, and draw a routing diagram of the optical cable based on the longitude and latitude coordinates, optical cable length, and optical cable routing direction of the optical cable stake point.

[0112] Refer to Figure 2 , the method for determining the optical cable routing direction of the optical cable stake point through tapping is as follows:

[0113] Taking the optical cable stake point as the center, select test points within a range with a radius of R; the spacing of the test points should not be too large, and can be set to 0.2 - 0.5 meters to ensure full coverage of the possible optical cable routing range.

[0114] Tap at each test point and extract the tapping vibration segment corresponding to each test point based on the vibration signal; at each test point, try to keep the force, frequency, and position of each tap the same as when tapping at the optical cable stake point to ensure the comparability of the generated vibration signals.

[0115] Calculate the average amplitude and frequency of the tapping vibration segment corresponding to each test point;

[0116] Calculate the deviation degree of each test point from the optical cable stake point; mark the test point with the smallest deviation degree from the optical cable stake point as the routing point; the calculation formula for the deviation degree is as follows:

[0117] ;

[0118] where, g represents the deviation degree of any test point from the optical cable stake point; represents the average amplitude of any test point; represents the main frequency of any test point; represents the frequency of the optical cable stake point;

[0119] Calculate the optical cable length of the routing point and record the longitude and latitude coordinates of the routing point; the optical cable length of the routing point is the length of the optical cable segment between the routing point and the transmitting end;

[0120] Determine the optical cable routing of the optical cable stake point based on the optical cable length of the optical cable stake point and the optical cable length of the routing point; specifically as follows: if the optical cable length of the optical cable stake point is greater than the optical cable length of the routing point, the optical cable routing of the optical cable stake point is from the routing point extending towards the optical cable stake point; if the optical cable length of the optical cable stake point is less than the optical cable length of the routing point, the optical cable routing of the optical cable stake point is from the optical cable stake point extending towards the routing point. Through the longitude and latitude coordinates of the optical cable stake point and the routing point, the approximate routing angle of the optical cable can be further calculated.

[0121] For each detailed information obtained for an optical cable stake point, the stake point can be created or updated in the routing map, adding or updating the optical cable number corresponding to the optical cable stake point, the longitude and latitude coordinates of the optical cable stake point, the optical cable length, the optical cable routing, the detailed address, the stake point type (such as station, well, utility pole, optical fiber distribution box, etc.), the stake point name, and a stake point note can be added, on-site photos and the waveform diagram of the corresponding vibration signal can be added, and the offset of the actual point position from the laid point position data can be calculated, etc. Implementing the above scheme for each optical cable stake point can obtain the above detailed information for all optical cable stake points; importing the above information into a Geographic Information System (GIS) can automatically draw a complete optical cable routing, accurately mark the optical cable routing, and visually display the distribution of the optical cable in the geographical space.

[0122] Embodiment 2

[0123] This embodiment is the second embodiment of the present invention; based on the same inventive concept as Embodiment 1, this embodiment introduces an optical cable routing census device based on fiber optic vibration sensing, including a pulsed light source, a fiber optic vibration sensor, a data processing module, a data storage module, and an intelligent mobile terminal; wherein:

[0124] The pulsed light source is used to send optical pulses to the optical cable; based on the adjustment instruction of the data processing module, the pulsed light source adjusts the pulse width sent to the optical cable; during the optical cable routing census process, during the tapping at the optical cable stake points by the construction personnel, the pulsed light source is remotely controlled to send optical pulses, so that the light propagates in the optical cable and generates a backward Rayleigh scattering signal for subsequent analysis.

[0125] The fiber optic vibration sensor is used to collect the vibration signals of the optical fiber and identify the tapping events in the vibration signals, and intercept the tapping vibration segments. By filtering, the vibration signals of the optical fiber are collected, that is, the backward Rayleigh scattering signals of the optical pulses, which can reflect the vibration conditions of the optical cable when subjected to external actions such as tapping.

[0126] The data processing module is used to calculate the adjustment amount of the pulse width and send an instruction to adjust the pulse width to the pulsed light source; the data processing module is also used to calculate the characteristic parameters of the tapping vibration segments and send corresponding prompts of tapping feedback to the mobile intelligent terminal;

[0127] The data storage module is used to store the relevant information of the optical cable stake points, including longitude and latitude coordinates, optical cable length, optical cable routing, optical cable number, stake point type, and stake point name; after obtaining the detailed information of each optical cable stake point, it is stored and updated, which is convenient for subsequent query and management, and also provides data support for drawing a complete optical cable routing map.

[0128] The intelligent mobile terminal is used to remotely control the turning on of the pulsed light source and receive the corresponding prompts of tapping feedback; the intelligent mobile terminal is also used to obtain the longitude and latitude coordinates of the optical cable stake points; the intelligent mobile terminal also includes GIS software for drawing and displaying the optical cable routing map. The intelligent mobile terminal facilitates the construction personnel to timely start the routing census and adjustment operations on site, improving the census efficiency.

[0129] For the specific function implementation of the above-mentioned modules, refer to the relevant content in the optical cable routing census method based on fiber optic vibration sensing described in Embodiment 1, which will not be elaborated here.

[0130] Those skilled in the art should understand that the embodiments of the present invention can be provided as a method, a system, or a computer program product. Therefore, the present invention can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk memory, CD-ROM, optical memory, etc.) that contain computer-usable program code.

[0131] The embodiments of the present invention have been described above in conjunction with the accompanying drawings. However, the present invention is not limited to the above specific embodiments. The above specific embodiments are merely illustrative and not restrictive. Under the inspiration of the present invention, those of ordinary skill in the art can also make many forms without departing from the spirit and scope of the present invention. All of these are within the protection scope of the present invention.

Claims

1. A method for general survey of optical cable routes based on optical fiber vibration sensing, characterized in that: It includes the following steps: S1: Strike at the optical cable stake point and remotely control the pulsed light source to send optical pulses to the optical cable; S2: Collect the vibration signals of the optical fiber and dynamically adjust the pulse width of the optical pulse based on the vibration parameters of the vibration signals; S3: Identify the knocking events in the vibration signals and intercept the knocking vibration segments from the vibration signals; the knocking vibration segments are the segments of the vibration signals corresponding to the knocking events; S4: Calculate the characteristic parameters of the knocking vibration segments and perform knocking feedback based on the characteristic parameters; The characteristic parameters of the knocking vibration segments include average amplitude, instability, and attenuation speed; The average amplitude of the optical cable pile points is denoted as , which is the mean value of the amplitudes of the percussion vibration segments; the instability is denoted as , which is the standard deviation of the amplitudes of the percussion vibration segments; the attenuation rate is denoted as , and the calculation method is as follows: Select two observation points on the same side of the optical cable pile on the optical cable, and denote them as P and Q respectively; among them, the distance between point P and the optical cable pile is , the distance between point Q and the optical cable pile is , and is greater than ; Locate points P and Q in the vibration signal and record the amplitude at point P, denoted as ; record the amplitude at point Q, denoted as ; Divide by the difference between and to obtain the attenuation rate; ​ The knocking feedback includes knocking position feedback and knocking force feedback; The specific method of the knocking position feedback is as follows: Set a decay rate threshold, denoted as ; If the decay rate is greater than , then give a prompt to change the tapping position; The specific method of the knocking force feedback is as follows: Set the minimum threshold of the average amplitude, denoted as ; Set the maximum threshold of the average amplitude, denoted as ; Set the instability threshold, denoted as ; If the average amplitude is less than , and the attenuation rate is not greater than , then a prompt for increasing the tapping force is given in feedback; If the average amplitude is greater than , and the instability is greater than , then give a prompt to reduce the tapping force in the feedback; The characteristic parameters of the tapping vibration segment further include a vibration frequency ratio; the vibration frequency ratio is denoted as , and the calculation method is as follows: perform spectral analysis on the tapping vibration segment to extract the peak frequency; the vibration frequency ratio is the average amplitude divided by the peak frequency; The knocking feedback further includes knocking frequency feedback, and the specific method is as follows: Set the minimum threshold of the vibration frequency ratio, denoted as ; Set the maximum threshold of the vibration frequency ratio, denoted as ; If the vibration frequency ratio is less than , then give a prompt to reduce the knocking frequency; If the vibration frequency ratio is greater than , then a prompt for increasing the knocking frequency is given. S5: Calculate the optical cable length of the optical cable stake point based on the knocking vibration segments and record the longitude and latitude coordinates of the optical cable stake point; S6: Determine the optical cable route of the optical cable stake point by knocking and draw the route map of the optical cable based on the longitude and latitude coordinates, optical cable length, and optical cable route of the optical cable stake point.

2. The method for general survey of optical cable routing based on optical fiber vibration sensing according to claim 1, wherein: The vibration signal of the optical fiber is the backward Rayleigh scattering signal of the optical pulse; The vibration parameters of the vibration signals include amplitude parameters and frequency parameters; the calculation method of the vibration parameters is as follows: filter and denoise the vibration signals; uniformly sample the vibration signals to obtain the amplitudes of N sampling points; calculate the mean value of the amplitudes of N sampling points as the amplitude parameter; perform frequency domain transformation on the vibration signals and extract the peak frequency of the vibration signals as the frequency parameter.

3. The method for general survey of optical cable routing based on optical fiber vibration sensing according to claim 2, wherein: The method for dynamically adjusting the pulse width of the optical pulse is as follows: Set the amplitude threshold and frequency threshold of the vibration signal; calculate the adjustment amount of the pulse width, denoted as ; Set the maximum value of the pulse width, denoted as ; Set the minimum value of the pulse width, denoted as ; Adjust the pulse width; Let the initial value of the pulse width be , and add to to obtain the adjusted pulse width of the optical pulse, denoted as w; If w is greater than , set the pulse width to ; if w is less than , set the pulse width to .

4. The optical cable routing census method based on fiber optic vibration sensing according to claim 3, wherein: The calculation method of the adjustment amount of the pulse width is as follows: Set the first adjustment amount and the second adjustment amount of the pulse width; If the amplitude parameter is greater than the amplitude threshold, assign a value based on the difference between the amplitude parameter and the amplitude threshold as the first adjustment amount; otherwise, the first adjustment amount is 0; If the frequency parameter is greater than the frequency threshold, assign a value based on the difference between the frequency parameter and the frequency threshold as the second adjustment amount; Otherwise, the second adjustment amount is 0; ​ 5. The optical cable routing census method based on optical fiber vibration sensing according to claim 4, characterized in that: ​ ​ ​ ​ ​ ​ ​ ​ 6. The method for general survey of optical cable routing based on optical fiber vibration sensing according to claim 5, characterized in that: The longitude and latitude coordinates of the optical cable stake points are obtained through a mobile terminal held by construction personnel and containing a GPS positioning module; the optical cable length of the optical cable stake points is the length of the optical cable section between the optical cable stake points and the transmitting end; the transmitting end is the optical cable port where a pulsed light source sends optical pulses to the optical cable; the optical cable length of the routing points is the length of the optical cable section between the routing points and the transmitting end; The method for determining the optical cable routing direction of the optical cable stake points based on the optical cable length of the optical cable stake points and the optical cable length of the routing points is as follows: If the optical cable length of the optical cable stake points is greater than the optical cable length of the routing points, the optical cable routing direction of the optical cable stake points is from the routing points extending towards the optical cable stake points; if the optical cable length of the optical cable stake points is less than the optical cable length of the routing points, the optical cable routing direction of the optical cable stake points is from the optical cable stake points extending towards the routing points.

7. An optical cable routing census device based on optical fiber vibration sensing, which is used to implement an optical cable routing census method based on optical fiber vibration sensing according to any one of claims 1-6, and is characterized in that: It includes a pulsed light source, an optical fiber vibration sensor, a data processing module, a data storage module, and an intelligent mobile terminal; among which: The pulsed light source is used to send optical pulses to the optical cable; the pulsed light source adjusts the pulse width sent to the optical cable based on the adjustment instruction of the data processing module; The optical fiber vibration sensor is used to collect the vibration signals of the optical fiber, identify the knocking events in the vibration signals, and intercept the knocking vibration segments; The data processing module is used to calculate the adjustment amount of the pulse width and send an instruction to adjust the pulse width to the pulsed light source; the data processing module is also used to calculate the characteristic parameters of the knocking vibration segments and send corresponding prompts for knocking feedback to the mobile intelligent terminal; The data storage module is used to store the relevant information of the optical cable stake points, including longitude and latitude coordinates, optical cable length, optical cable routing direction, optical cable number, stake point type, and stake point name; The intelligent mobile terminal is used to remotely control the turning on of the pulsed light source and receive the corresponding prompts for knocking feedback; the intelligent mobile terminal is also used to obtain the longitude and latitude coordinates of the optical cable stake points; the intelligent mobile terminal also includes GIS software for drawing and displaying the optical cable routing map.

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