Dispersion-based unidirectional optical fiber communication and distributed sensing depth fusion positioning method and system, terminal and storage medium

Abstract

The invention belongs to the technical field of optical engineering, and discloses a dispersion-based one-way optical fiber communication and distributed sensing depth fusion positioning method and system, a terminal and a storage medium, and the method comprises the steps: inputting optical signals with different wavelengths into corresponding modulators, enabling the modulated optical signals to enter the same optical fiber through a wavelength division multiplexer, and enabling the optical signals to enter the same optical fiber; transmitting to a receiving end in a one-way transmission mode; extracting an optical phase of an optical signal in the receiving end based on an autocorrelation technology, and analyzing a range-resolved vibration signal, a vibration amplitude and a vibration frequency; and calculating the time difference of the vibration signal according to the distance resolution vibration signal, the vibration amplitude and the vibration frequency, and calculating the position of vibration according to the time difference. According to the invention, the forward transmission continuous wave light is used for replacing weak backward scattering light, so that an ultra-long sensing distance is realized, and vibration positioning can be realized without an ultra-narrow laser line width by adopting self-coherent demodulation, so that the cost is reduced, and the positioning mode is simplified.

Description

Technical Field

[0001] The present invention relates to the field of optical engineering technology, and in particular to a dispersion-based unidirectional optical fiber communication and distributed sensing deep fusion positioning method, system, terminal and storage medium. Background Art

[0002] Building a comprehensive real-time vibration monitoring network can provide better support for disaster warning and decision-making. However, in practice, deploying large-scale sensor arrays is not only extremely cumbersome but also costly.

[0003] Distributed fiber optic sensors, with their advantages of high sensitivity, wide dynamic range, strong reliability, spatially resolved information collection capabilities, and resistance to electromagnetic interference, offer a new approach to addressing these challenges. If specific technologies are employed to enable the optical fibers in these communication cables to not only perform normal communication functions but also sense various physical events, achieving integrated synaesthesia, a global information collection network could be rapidly and cost-effectively established, significantly driving the development of next-generation Internet of Things technologies. Among existing fiber optic sensors, optical frequency domain reflectometry (OFDR) is commonly used for short-distance measurements. Phase-sensitive optical time domain reflectometry (φ-OTDR, also known as distributed acoustic sensing, or DAS) focuses on medium-range and medium-spatial resolution applications. Without optical amplifiers, their maximum sensing distance can reach tens of kilometers. Both technologies require additional hardware to effectively collect and process backscattered light signals. Therefore, key challenges currently lie in sensing distance, detection limit, and cost.

[0004] Remote sensing systems with long sensing fibers can significantly reduce the resources, power consumption, and maintenance costs required to support detection systems. Integrating these systems with existing optical communication systems can further reduce overall costs and simplify maintenance workflows.

[0005] Among existing long-distance distributed sensing technologies, forward transmission sensing is a relatively new distributed sensing method that is substantially different from the common light backscattering measurement method. This is because the propagation direction of the optical signal is similar to that of optical communication, and the existing fiber-optic communication system and optical signal can be used without hardware modification. The characteristics of different wavelengths of light waves with different dispersions are used to calculate the location of the vibration. The advantage of this type of technology is that it can be more easily installed and maintained in long-distance and remote environments. The currently reported designs rely on expensive high-coherence laser sources or complex system layouts based on reference optical fibers, and lack a universal multi-point vibration positioning method.

[0006] Therefore, the existing technology needs to be improved. Summary of the Invention

[0007] The technical problem to be solved by the present invention is that, in response to the defects of the existing technology, the present invention provides a dispersion-based unidirectional optical fiber communication and distributed sensing deep fusion positioning method, system, terminal and storage medium to solve the problems of high cost and complex positioning methods of existing long-distance distributed sensing technology.

[0008] The technical solutions adopted by the present invention to solve the technical problems are as follows: In a first aspect, the present invention provides a method for deep fusion positioning of unidirectional optical fiber communication and distributed sensing based on dispersion, comprising: Optical signals of different wavelengths are input into corresponding modulators respectively, and the modulated optical signals are sent into the same optical fiber using a wavelength division multiplexer and transmitted to the receiving end in a unidirectional manner; Extracting the optical phase of the optical signal in the receiving end based on autocorrelation technology, and analyzing the distance-resolved vibration signal, vibration amplitude and vibration frequency; A time difference of the vibration signal is calculated according to the distance-resolved vibration signal, the vibration amplitude, and the vibration frequency, and a position where the vibration occurs is calculated according to the time difference.

[0009] In one implementation, extracting the optical phase of the optical signal in the receiving end based on the autocorrelation technology and analyzing the distance-resolved vibration signal, vibration amplitude, and vibration frequency includes: The optical signals of different wavelengths are separated by a wavelength division multiplexer, and the separated optical signals enter their respective demodulation ends; The optical phase of the corresponding optical signal is extracted through each demodulation end, and the distance-resolved vibration signal, the vibration amplitude and the vibration frequency are analyzed according to the optical phase to obtain the vibration signal information on the optical fiber path.

[0010] In one implementation, extracting the optical phase of the corresponding optical signal through the respective demodulation ends includes: Obtain the input voltage signal of the photoelectric balance detection module at the demodulation end: ; ; in, 、 Respectively represent the two input voltage signals of the photoelectric balance detection module; , , , represents a constant coefficient; represents the phase of the vibration signal, Represents the sum of all types of phase noise; Perform high-pass filtering on the input voltage signal to remove the low-frequency DC component: ; ; Perform signal division and inverse tangent processing based on the filtered voltage signal: ; The optical phase is calculated based on the phase of the vibration signal obtained through arc tangent processing.

[0011] In one implementation, calculating the optical phase based on the phase of the vibration signal obtained by arc tangent processing includes: Get the frequency drift information of the laser: ; in, Indicates the drift of the laser frequency, Indicates the length of the optical fiber, Indicates the speed of light in the core material of an optical fiber; Calculate the optical phase according to the phase of the vibration signal, the frequency drift information, and the communication signal phase: ; in, Indicates the phase of the vibration signal; Indicates the phase of the communication signal; Indicates the frequency drift information.

[0012] In one implementation, calculating the time difference of the vibration signal according to the distance-resolved vibration signal, the vibration amplitude, and the vibration frequency, and calculating the position where the vibration occurs according to the time difference, includes: Calculating the time difference of the vibration signal using a cross-correlation algorithm or a phase spectrum positioning method according to the distance-resolved vibration signal, the vibration amplitude, and the vibration frequency; Calculate the location where the vibration signal occurs based on the time difference of the vibration signal: ; in, Indicates the dispersion coefficient of a preset wavelength band in a single-mode optical fiber; and Represent the central wavelengths of the two light waves respectively; It indicates the time difference between output optical signals of different wavelengths caused by chromatic dispersion.

[0013] In one implementation, the calculating the time difference of the vibration signal using a cross-correlation algorithm or a phase spectrum positioning method according to the distance-resolved vibration signal, the vibration amplitude, and the vibration frequency includes: Determine the cross-correlation function: ; in, and Respectively represent the phase signals obtained by demodulating the two wavelengths of light waves; The time difference of the vibration signals is calculated according to the cross-correlation function.

[0014] In one implementation, the calculating the time difference of the vibration signal using a cross-correlation algorithm or a phase spectrum positioning method based on the distance-resolved vibration signal, the vibration amplitude, and the vibration frequency further includes: Perform Fourier transform on the cross-correlation function: ;in, Represents the frequency domain characteristics after Fourier transform; Calculate the amplitude spectrum and phase spectrum of different frequencies respectively through the spectrum: ; ; in, represents the amplitude spectrum; represents the phase spectrum; Calculate the time delay between different frequencies based on the phase spectrum: ; in, represents the time difference; represents the vibration frequency.

[0015] In a second aspect, the present invention provides a dispersion-based unidirectional optical fiber communication and distributed sensing deep fusion positioning system, comprising: The unidirectional transmission module is used to input optical signals of different wavelengths into corresponding modulators respectively, and use the wavelength division multiplexer to transmit the modulated optical signals into the same optical fiber and transmit them to the receiving end in a unidirectional transmission manner; an optical signal analysis module for extracting the optical phase of the optical signal in the receiving end based on autocorrelation technology, and analyzing the distance-resolved vibration signal, vibration amplitude, and vibration frequency; The vibration position calculation module is used to calculate the time difference of the vibration signal according to the distance-resolved vibration signal, the vibration amplitude and the vibration frequency, and calculate the position where the vibration occurs according to the time difference.

[0016] In a third aspect, the present invention provides a terminal comprising: a processor and a memory, wherein the memory stores a dispersion-based unidirectional optical fiber communication and distributed sensing deep fusion positioning program, and when the dispersion-based unidirectional optical fiber communication and distributed sensing deep fusion positioning program is executed by the processor, it is used to implement the operation of the dispersion-based unidirectional optical fiber communication and distributed sensing deep fusion positioning method as described in the first aspect.

[0017] In a fourth aspect, the present invention also provides a computer-readable storage medium, which stores a dispersion-based unidirectional optical fiber communication and distributed sensing deep fusion positioning program, and when the dispersion-based unidirectional optical fiber communication and distributed sensing deep fusion positioning program is executed by a processor, it is used to implement the operation of the dispersion-based unidirectional optical fiber communication and distributed sensing deep fusion positioning method as described in the first aspect.

[0018] The present invention adopts the above technical solution to achieve the following effects: The present invention inputs optical signals of different wavelengths into corresponding modulators, and uses a wavelength division multiplexer to transmit the modulated optical signals into the same optical fiber for unidirectional transmission to the receiving end. The optical phase of the optical signal at the receiving end is extracted based on autocorrelation technology, and the distance-resolved vibration signal, vibration amplitude, and vibration frequency are analyzed. The time difference of the vibration signal is calculated based on the distance-resolved vibration signal, vibration amplitude, and vibration frequency, and the location of the vibration is calculated based on the time difference. By using forward-transmitted continuous wave light instead of weak backscattered light, the present invention achieves an ultra-long sensing distance. Furthermore, by employing autocoherent demodulation, vibration positioning can be achieved without the need for an ultra-narrow laser linewidth, reducing costs and simplifying positioning methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0020] Figure 1 This is a flow chart of the dispersion-based unidirectional optical fiber communication and distributed sensing deep fusion positioning method in the present invention.

[0021] Figure 2 It is a structural diagram of the dispersion-based unidirectional optical fiber communication and distributed sensing deep fusion positioning system in the present invention.

[0022] Figure 3 It is a functional principle diagram of a terminal in one implementation of the present invention.

[0023] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solutions and advantages of the present invention more clear and distinct, the present invention is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0025] Exemplary Methods Among existing long-distance distributed sensing technologies, forward transmission sensing is a relatively new distributed sensing method that is substantially different from the common light backscattering measurement method. This is because the propagation direction of the optical signal is similar to that of optical communication, and the existing fiber-optic communication system and optical signal can be used without hardware modification. The characteristics of different wavelengths of light waves with different dispersions are used to calculate the location of the vibration. The advantage of this type of technology is that it can be more easily installed and maintained in long-distance and remote environments. The currently reported designs rely on expensive high-coherence laser sources or complex system layouts based on reference optical fibers, and lack a universal multi-point vibration positioning method.

[0026] In response to the above technical problems, an embodiment of the present invention provides a method for positioning by deep fusion of one-way fiber optic communication and distributed sensing based on dispersion, including: inputting optical signals of different wavelengths into corresponding modulators respectively, and using a wavelength division multiplexer to input the modulated optical signals into the same optical fiber, and transmitting them to the receiving end in a one-way transmission manner; extracting the optical phase of the optical signal in the receiving end based on autocorrelation technology, and analyzing the distance-resolved vibration signal, vibration amplitude and vibration frequency; calculating the time difference of the vibration signal based on the distance-resolved vibration signal, the vibration amplitude and the vibration frequency, and calculating the position where the vibration occurs based on the time difference. The present invention achieves an ultra-long sensing distance by using forward-transmitted continuous wave light instead of weak backscattered light, and by adopting self-coherent demodulation, vibration positioning can be achieved without the need for ultra-narrow laser linewidth, thereby reducing costs and simplifying the positioning method.

[0027] like Figure 1 As shown, an embodiment of the present invention provides a dispersion-based unidirectional optical fiber communication and distributed sensing deep fusion positioning method, comprising the following steps: Step S100: Inputting optical signals of different wavelengths into corresponding modulators respectively, and using a wavelength division multiplexer to transmit the modulated optical signals into the same optical fiber, and transmitting them to the receiving end in a unidirectional transmission manner; Step S200: extracting the optical phase of the optical signal in the receiving end based on the autocorrelation technology, and analyzing the distance-resolved vibration signal, vibration amplitude and vibration frequency.

[0028] In this embodiment, the dispersion-based unidirectional optical fiber communication and distributed sensing deep fusion positioning method is a method for vibration positioning based on forward transmission optical fiber sensing technology using dispersion effect. This method can be implemented by a dispersion-based unidirectional optical fiber communication and distributed sensing deep fusion positioning system. The structure of the system is as follows: Figure 2 shown.

[0029] In this embodiment, based on Figure 2 In the system shown in the figure, two light waves of different wavelengths are each passed through a QPSK (Quadrature Phase Shift Keying, a digital modulation method) modulator. Then, the two light waves carrying communication signals (for example, 1530.334nm and 1560.606nm) enter the same optical fiber through a WDM (Wavelength Division Multiplexing) and are transmitted unidirectionally through the same optical fiber to the receiving end.

[0030] Specifically, in one implementation of this embodiment, step S200 includes the following steps: Step S201, separating optical signals of different wavelengths by a wavelength division demultiplexer, and sending the separated optical signals to respective demodulation terminals; Step S202: extract the optical phase of the corresponding optical signal through the respective demodulation ends, and analyze the distance-resolved vibration signal, the vibration amplitude and the vibration frequency according to the optical phase to obtain the vibration signal information on the optical fiber path.

[0031] In this embodiment, the receiving end uses a self-coherent structure for phase demodulation. At the receiving end, the two different wavelengths of light are separated by the DWDM (Dense Wavelength Division Multiplexing) demultiplexer and enter their respective demodulation ends. After the demodulation system and signal processing and analysis, the vibration signal on the optical fiber path is obtained to achieve sensing.

[0032] At the demodulation end of the vibration signal, the signal light is split into two paths by a coupler. One path enters the mixer directly; the other path enters the delay fiber, is reflected by a Faraday rotator (FRM), and then enters the mixer, acting as the intrinsic light in the interference. The four output signals from the mixer are 0°, 90°, 180°, and 270°. By connecting the 0° and 180° signals to a BPD module (the first photoelectric balance detection module) and the 90° and 270° signals to another BPD module (the second photoelectric balance detection module), the influence of the DC component is eliminated. Finally, by sampling the output voltage signals of the two BPD modules, the vibration phase is determined using phase demodulation.

[0033] In this embodiment, after extracting the optical phase of the corresponding optical signal through each demodulation end, the distance-resolved vibration signal, the vibration amplitude and the vibration frequency can be analyzed according to the optical phase, thereby obtaining the vibration signal information on the optical fiber path.

[0034] Different from the traditional dual-optical path structure, the sensing structure of this embodiment only uses a single optical path for unidirectional transmission, and uses wavelength division multiplexing technology to allow light of different wavelengths to propagate on the same optical fiber. When a disturbance occurs on the optical fiber path, the phase of light waves of different wavelengths will change. However, due to the dispersion effect, the propagation speed of light of different wavelengths is different, and the time it takes for the phase change caused by the disturbance to reach the receiving end is also different. The farther the vibration position is from the detector at the receiving end, the greater the time delay. For example, when two light waves with a wavelength difference of 30nm are used, a disturbance occurs at a distance of 50km from the detector. At this time, a high-sampling-rate oscilloscope is used to collect the signal. Further analysis of the signal can determine a time delay of 24ns. If the disturbance occurs at a distance of 100km, the time delay generated is 48ns. The location of the disturbance can be determined by detecting the time delay.

[0035] Specifically, in one implementation of this embodiment, step S201 includes the following steps: Step S201a, obtaining an input voltage signal of the photoelectric balance detection module at the demodulation end; Step S201b, performing high-pass filtering on the input voltage signal to remove low-frequency DC components; Step S201c, performing signal division and arc tangent processing according to the filtered voltage signal; Step S201d: Calculate the optical phase based on the phase of the vibration signal obtained by arc tangent processing.

[0036] In this embodiment, for the demodulation end of one wavelength, the input voltage signal of the corresponding BPD module can be expressed as: ; ; in, 、 Respectively represent the two input voltage signals of the photoelectric balance detection module; , , , represents a constant coefficient; represents the phase of the vibration signal, Represents the sum of all types of phase noise.

[0037] In actual scenarios, , , , It can be a coefficient determined by a scaling factor related to some low-frequency components, phase mismatch, the responsivity of the photodiode, and the coupling coefficient of the coupler. Since the optical paths for receiving the two signals are completely symmetrical and the specifications of the devices used are exactly the same, b and d can be approximately considered equal.

[0038] After obtaining the input voltage signal of the BPD module, perform high-pass filtering on the signal to remove the low-frequency DC component: ; ; Subsequently, according to 、 Divide the signal and perform inverse tangent processing: ; Afterwards, the optical phase can be calculated based on the phase of the vibration signal obtained by arc tangent processing.

[0039] In this embodiment, the optical phase is calculated based on the phase of the vibration signal obtained by inverse tangent processing, including the following steps: obtaining the frequency drift information of the laser; and calculating the optical phase based on the phase of the vibration signal, the frequency drift information and the phase of the communication signal.

[0040] It is worth noting that when combined with an optical communication system, unlike expensive narrow-linewidth lasers, the lasers used in this embodiment often have a certain frequency drift, the impact of which is directly reflected in the demodulated phase; therefore, it is necessary to determine the laser's frequency drift information: ; in, Indicates the drift of the laser frequency, Indicates the length of the optical fiber, Indicates the speed of light in the core material of an optical fiber.

[0041] Moreover, since both the communication signal and the vibration signal are transmitted by the phase of the light wave, the demodulated phase signal is often affected by the communication signal. In other words, the communication signal itself can be regarded as a kind of noise for the vibration signal. It is actually the sum of the phase of the vibration signal, the phase of the communication signal, and the phase fluctuation caused by the laser frequency drift: ; in, Indicates the phase of the vibration signal; Indicates the phase of the communication signal; Indicates the frequency drift information.

[0042] These signals are uncorrelated and clearly distinguishable in the frequency domain. Bandpass filtering within the expected frequency range of the vibration signal can extract the vibration phase signal. Subsequently, using methods such as cross-correlation or phase spectrum localization, the time delay between the two lightwave phases can be determined.

[0043] In this embodiment, the phase demodulation of another wavelength also adopts the above-mentioned optical phase extraction solution of the optical signal.

[0044] like Figure 1 As shown, an embodiment of the present invention provides a dispersion-based unidirectional optical fiber communication and distributed sensing deep fusion positioning method, comprising the following steps: Step S300 , calculating a time difference of the vibration signal according to the distance-resolved vibration signal, the vibration amplitude, and the vibration frequency, and calculating a position where the vibration occurs according to the time difference.

[0045] In this embodiment, the time difference of the vibration signal is calculated based on the dispersion effect positioning method, and the position where the vibration occurs is calculated according to the time difference.

[0046] Specifically, in one implementation of this embodiment, step S300 includes the following steps: Step S301, calculating the time difference of the vibration signal using a cross-correlation algorithm or a phase spectrum positioning method according to the distance-resolved vibration signal, the vibration amplitude, and the vibration frequency; Step S302: Calculate the location where the vibration signal occurs based on the time difference of the vibration signal.

[0047] In this embodiment, when light propagates through an optical fiber, it not only experiences optical power attenuation due to inherent fiber losses but also walk-off between light waves of different wavelengths due to the dispersion effect. Therefore, a method based on the dispersion effect is used to locate the vibration location. Dispersion is typically expressed as the dispersion coefficient, measured in ps / (nm·km). For single-mode optical fiber, modal dispersion does not exist due to single-mode transmission. The primary cause of walk-off is material dispersion.

[0048] Specifically, material dispersion is caused by the nonlinear variation of the refractive index of the optical fiber material with the wavelength of the light wave. For single-mode silica fiber, it can be expressed as: ; in, is the refractive index of the medium, is the wavelength of light, is the speed of light in a vacuum; the refractive index of quartz varies with wavelength. This is essentially due to the interaction between light waves and the vibrations of quartz electrons, causing different wavelengths of light to propagate at different speeds through the material. When a vibration occurs along a long sensing fiber, the time delay between the vibration location and the two photodetectors is determined by the dispersion coefficient corresponding to the respective wavelengths and the propagation distance. Further analysis of the signal can determine the time delay and the location of the disturbance.

[0049] In this embodiment, two continuous lasers with central wavelengths of 1530.334nm (195.9THz) and 1560.606nm (192.1THz) are used. When they propagate in the optical fiber, the propagation speeds of the optical signals of these two wavelengths will be different due to dispersion. On this basis, when a disturbance occurs in the optical fiber path, the resulting phase change will also arrive at the receiving end at different times. Except for the time delay caused by fiber dispersion, the interference patterns detected by the two photodetectors with different wavelengths are almost the same. The walk-off effect between the two output optical signals of different wavelengths caused by dispersion can be expressed as ,in, represents the dispersion coefficient in the optical fiber, Indicates the length of the optical fiber.

[0050] At this point, the location where the disturbance occurred can be calculated based on the time difference of the phase signal demodulated by the receiving end. It can be determined by the following formula: ; in, Indicates the dispersion coefficient of a preset wavelength band in a single-mode optical fiber, which is 16 ps / nm·km; and Represent the central wavelengths of the two light waves respectively; Indicates the time difference between the output optical signals of different wavelengths caused by dispersion. In general, the core of vibration positioning is to detect the time delay of two phase signals. .

[0051] In this embodiment, after the two demodulation ends respectively demodulate to obtain the phase signals corresponding to the two wavelengths, the time difference of the vibration signal is calculated using a cross-correlation algorithm or a phase spectrum positioning method; wherein, the specific method of calculating using the cross-correlation algorithm is as follows.

[0052] Specifically, in one implementation of this embodiment, step S301 includes the following steps: Step S301a, determining a cross-correlation function; Step S301b: calculating the time difference of the vibration signal according to the cross-correlation function.

[0053] In this embodiment, after the two demodulation ends respectively demodulate and obtain the phase signals corresponding to the two wavelengths, the similarity between the two signals and their time offset relationship are analyzed. The time delay can be obtained by a cross-correlation algorithm or a phase spectrum algorithm.

[0054] The cross-correlation algorithm calculates the cross-correlation function of two signals and finds the time point corresponding to the function peak. This time point represents the time delay between the two signals. The cross-correlation function is defined as: ; in, and They represent the phase signals obtained by demodulating the two wavelengths of light waves.

[0055] Since the two signals are exactly the same in waveform, when the time delay is taken as the actual signal delay When , the function reaches its maximum value. This is the time delay between the two signals. In the case of a single point vibration, the cross-correlation algorithm can directly calculate the time delay of the signal.

[0056] Specifically, in one implementation of this embodiment, step S301 further includes the following steps: Step S301c, performing Fourier transform on the cross-correlation function; Step S301d, calculating the amplitude spectrum and phase spectrum of different frequencies respectively through the frequency spectrum; Step S301e: Calculate the time delay between different frequencies according to the phase spectrum.

[0057] In this embodiment, the phase spectrum method performs Fourier transform on the cross-correlation function based on the cross-correlation algorithm, and then analyzes it in the frequency domain.

[0058] Therefore, we first need to perform Fourier transform on the above cross-correlation function: ;in, Represents the frequency domain characteristics after Fourier transform; Then, the amplitude spectrum and phase spectrum of different frequencies are calculated respectively through the spectrum: ; ; in, represents the amplitude spectrum; represents the phase spectrum; Therefore, the time delay between different frequencies for phase spectrum calculation can be expressed as: ; in, represents the time difference; represents the vibration frequency.

[0059] In this embodiment, the phase spectrum method can realize the calculation of time delays for different frequency components of the signal. When vibration signals occurring at different locations can be distinguished in frequency, this method can be used to realize multi-point vibration detection.

[0060] In this embodiment, the time difference of the vibration signal is calculated by the above two methods, and the above formula is used according to the time difference of the vibration signal. The location where the vibration signal occurs can be calculated.

[0061] This embodiment utilizes a novel fiber-optic acoustic sensor or vibration sensor with a novel dispersion-based forward transmission, achieving a sensing range of at least 150 kilometers without the need for an optical amplifier. Autocorrelation technology is used to extract the optical phase, analyze the distance-resolved vibration signal, as well as the vibration amplitude and frequency, and then calculate the vibration location using the time difference. When analyzing the signal at the receiving end, the cross-correlation spectrum is used to perform an FFT (Fourier transform) to obtain the phase spectrum, thereby estimating the vibration location source of each frequency component. The sensing method of this embodiment has multiple advantages, including: 1) Higher signal-to-noise ratio (the optical power is several orders of magnitude higher than the backscattered light) and is not affected by Rayleigh backscattering noise; 2) Fewer nonlinear effects (continuous wave light); 3) Longer sensing distance to avoid optical amplifiers (easier to install and maintain); 4) Spatial resolution is not directly related to sensing range (allowing separate optimization without trade-offs); 5) Unlike a double-ended OTDR (Optical Time Domain Reflectometry) system, there is no weak SNR (Signal-to-Noise Ratio) region in the middle of the sensing fiber.

[0062] 6) It can be directly integrated with the optical fiber communication system without the need for dark fiber or other additional hardware facilities.

[0063] 7) All demodulation equipment is placed on one side to facilitate time synchronization.

[0064] As an alternative to this embodiment, the detection frequency range and detection distance of the distributed vibration fiber sensor implemented in this embodiment can be adaptively changed. The fiber type can be changed to include specialized vibration-sensitive fibers or other types of fibers, such as multi-core fibers and polarization-maintaining fibers. The laser wavelength range can also be changed. Furthermore, different demodulation methods can be applied, such as heterodyne IQ demodulation (a signal processing technique). Furthermore, other properties of light waves, such as polarization state, can be utilized for sensing, at the expense of a certain degree of positioning accuracy.

[0065] This embodiment achieves the following technical effects through the above technical solution: This embodiment utilizes the dispersion effect of optical fiber to detect phase changes and locate vibrations along a single optical fiber, and deeply integrates them into the optical fiber communication system. In addition, by using forward-transmitted continuous-wave light instead of weak backscattered light, an ultra-long sensing distance is achieved. By adopting self-coherent demodulation, vibration positioning can be achieved without the need for an ultra-narrow laser linewidth, thereby reducing costs and simplifying the positioning method. The sensing system used in this embodiment can be directly combined with the existing optical communication system without the need to reserve additional dark optical fiber, and can be directly deployed on the existing optical communication system to realize communication and sensing integration.

[0066] Exemplary devices Based on the above embodiments, the present invention further provides a dispersion-based unidirectional optical fiber communication and distributed sensing deep fusion positioning system, comprising: The unidirectional transmission module is used to input optical signals of different wavelengths into corresponding modulators respectively, and use the wavelength division multiplexer to transmit the modulated optical signals into the same optical fiber and transmit them to the receiving end in a unidirectional transmission manner; an optical signal analysis module for extracting the optical phase of the optical signal in the receiving end based on autocorrelation technology, and analyzing the distance-resolved vibration signal, vibration amplitude, and vibration frequency; The vibration position calculation module is used to calculate the time difference of the vibration signal according to the distance-resolved vibration signal, the vibration amplitude and the vibration frequency, and calculate the position where the vibration occurs according to the time difference.

[0067] This embodiment achieves the following technical effects through the above technical solution: This embodiment utilizes the dispersion effect of optical fiber to detect phase changes and locate vibrations along a single optical fiber, and deeply integrates them into the optical fiber communication system. In addition, by using forward-transmitted continuous-wave light instead of weak backscattered light, an ultra-long sensing distance is achieved. By adopting self-coherent demodulation, vibration positioning can be achieved without the need for an ultra-narrow laser linewidth, thereby reducing costs and simplifying the positioning method. The sensing system used in this embodiment can be directly combined with the existing optical communication system without the need to reserve additional dark optical fiber, and can be directly deployed on the existing optical communication system to realize communication and sensing integration.

[0068] Based on the above embodiment, the present invention further provides a terminal, whose principle block diagram can be shown as follows: Figure 3 shown.

[0069] The terminal includes: a processor, memory, interface, display screen and communication module connected via a system bus; wherein the processor of the terminal is used to provide computing and control capabilities; the memory of the terminal includes a computer-readable storage medium and an internal memory; the computer-readable storage medium stores an operating system and a computer program; the internal memory provides an environment for the operation of the operating system and computer program in the computer-readable storage medium; the interface is used to connect to external devices; the display screen is used to display corresponding information; and the communication module is used to communicate with a cloud server or other devices.

[0070] When the computer program is executed by a processor, it is used to implement the operation of a dispersion-based unidirectional optical fiber communication and distributed sensing deep fusion positioning method.

[0071] It will be understood by those skilled in the art that Figure 3 The principle block diagram shown in the figure is only a block diagram of a partial structure related to the solution of the present invention, and does not constitute a limitation on the terminal to which the solution of the present invention is applied. The specific terminal may include more or fewer components than shown in the figure, or combine certain components, or have a different component arrangement.

[0072] In one embodiment, a terminal is provided, which includes: a processor and a memory, the memory storing a dispersion-based unidirectional optical fiber communication and distributed sensing deep fusion positioning program, and the dispersion-based unidirectional optical fiber communication and distributed sensing deep fusion positioning program is used to implement the above-mentioned dispersion-based unidirectional optical fiber communication and distributed sensing deep fusion positioning method when executed by the processor.

[0073] In one embodiment, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores a dispersion-based unidirectional optical fiber communication and distributed sensing deep fusion positioning program, and when the dispersion-based unidirectional optical fiber communication and distributed sensing deep fusion positioning program is executed by a processor, it is used to implement the operation of the above-mentioned dispersion-based unidirectional optical fiber communication and distributed sensing deep fusion positioning method.

[0074] Those skilled in the art will appreciate that all or part of the processes in the above-described method embodiments can be implemented by instructing the relevant hardware through a computer program. The computer program can be stored in a non-volatile storage medium. When executed, the computer program can include the processes in the above-described method embodiments. Any reference to memory, storage, database, or other media used in the various embodiments provided herein may include both non-volatile and volatile memory.

[0075] In summary, the present invention provides a method, system, terminal and storage medium for positioning based on dispersion-based unidirectional optical fiber communication and distributed sensing deep fusion, including: inputting optical signals of different wavelengths into corresponding modulators respectively, and using a wavelength division multiplexer to input the modulated optical signals into the same optical fiber, and transmitting them to the receiving end in a unidirectional transmission manner; extracting the optical phase of the optical signal in the receiving end based on autocorrelation technology, and analyzing the distance-resolved vibration signal, vibration amplitude and vibration frequency; calculating the time difference of the vibration signal according to the distance-resolved vibration signal, the vibration amplitude and the vibration frequency, and calculating the position where the vibration occurs according to the time difference. The present invention achieves an ultra-long sensing distance by using forward-transmitted continuous wave light instead of weak backscattered light, and by adopting autocoherent demodulation, vibration positioning can be achieved without the need for an ultra-narrow laser linewidth, thereby reducing costs and simplifying the positioning method.

[0076] It should be understood that the application of the present invention is not limited to the above examples. For those skilled in the art, improvements or changes can be made based on the above description. All these improvements and changes should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A dispersion-based unidirectional optical fiber communication and distributed sensing deep fusion positioning method, characterized in that: include: Optical signals of different wavelengths are input into corresponding modulators respectively, and the modulated optical signals are sent into the same optical fiber using a wavelength division multiplexer and transmitted to the receiving end in a unidirectional manner; Extracting the optical phase of the optical signal in the receiving end based on autocorrelation technology, and analyzing the distance-resolved vibration signal, vibration amplitude and vibration frequency; A time difference of the vibration signal is calculated according to the distance-resolved vibration signal, the vibration amplitude, and the vibration frequency, and a position where the vibration occurs is calculated according to the time difference.

2. The method for deep fusion positioning of unidirectional optical fiber communication and distributed sensing based on dispersion according to claim 1 is characterized in that: The extracting of the optical phase of the optical signal in the receiving end based on the autocorrelation technology and analyzing the distance-resolved vibration signal, vibration amplitude and vibration frequency include: The optical signals of different wavelengths are separated by a wavelength division multiplexer, and the separated optical signals enter their respective demodulation ends; The optical phase of the corresponding optical signal is extracted through each demodulation end, and the distance-resolved vibration signal, the vibration amplitude and the vibration frequency are analyzed according to the optical phase to obtain the vibration signal information on the optical fiber path.

3. The method for deep fusion positioning of unidirectional optical fiber communication and distributed sensing based on dispersion according to claim 2 is characterized in that: The extracting the optical phase of the corresponding optical signal through the respective demodulation ends includes: Obtain the input voltage signal of the photoelectric balance detection module at the demodulation end: ； ； in, 、 Respectively represent the two input voltage signals of the photoelectric balance detection module; , , , represents a constant coefficient; represents the phase of the vibration signal, Represents the sum of all types of phase noise; Perform high-pass filtering on the input voltage signal to remove the low-frequency DC component: ； ； Perform signal division and inverse tangent processing based on the filtered voltage signal: ； The optical phase is calculated based on the phase of the vibration signal obtained through arc tangent processing.

4. The method for deep fusion positioning of unidirectional optical fiber communication and distributed sensing based on dispersion according to claim 3 is characterized in that: The optical phase is obtained by calculating the phase of the vibration signal obtained by arc tangent processing, comprising: Get the frequency drift information of the laser: ； in, Indicates the drift of the laser frequency, Indicates the length of the optical fiber, Indicates the speed of light in the core material of an optical fiber; Calculate the optical phase according to the phase of the vibration signal, the frequency drift information, and the communication signal phase: ； in, Indicates the phase of the vibration signal; Indicates the phase of the communication signal; Indicates the frequency drift information.

5. The method for deep fusion positioning of unidirectional optical fiber communication and distributed sensing based on dispersion according to claim 1 is characterized in that: The step of calculating a time difference of the vibration signal according to the distance-resolved vibration signal, the vibration amplitude, and the vibration frequency, and calculating a position where the vibration occurs according to the time difference, includes: Calculating the time difference of the vibration signal using a cross-correlation algorithm or a phase spectrum positioning method according to the distance-resolved vibration signal, the vibration amplitude, and the vibration frequency; Calculate the location where the vibration signal occurs based on the time difference of the vibration signal: ； in, Indicates the dispersion coefficient of a preset wavelength band in a single-mode optical fiber; and Represent the central wavelengths of the two light waves respectively; It indicates the time difference between output optical signals of different wavelengths caused by chromatic dispersion.

6. The method for deep fusion positioning of unidirectional optical fiber communication and distributed sensing based on dispersion according to claim 5, characterized in that: The calculating the time difference of the vibration signal by using a cross-correlation algorithm or a phase spectrum positioning method according to the distance-resolved vibration signal, the vibration amplitude, and the vibration frequency includes: Determine the cross-correlation function: ； in, and Respectively represent the phase signals obtained by demodulating the two wavelengths of light waves; The time difference of the vibration signals is calculated according to the cross-correlation function.

7. The method for deep fusion positioning of unidirectional optical fiber communication and distributed sensing based on dispersion according to claim 6 is characterized in that: The step of calculating the time difference of the vibration signal by using a cross-correlation algorithm or a phase spectrum positioning method according to the distance-resolved vibration signal, the vibration amplitude, and the vibration frequency further includes: Perform Fourier transform on the cross-correlation function: ;in, Represents the frequency domain characteristics after Fourier transform; Calculate the amplitude spectrum and phase spectrum of different frequencies respectively through the spectrum: ； ； in, represents the amplitude spectrum; represents the phase spectrum; Calculate the time delay between different frequencies based on the phase spectrum: ； in, represents the time difference; represents the vibration frequency.

8. A dispersion-based unidirectional optical fiber communication and distributed sensing deep fusion positioning system, characterized in that: include: The unidirectional transmission module is used to input optical signals of different wavelengths into corresponding modulators respectively, and use the wavelength division multiplexer to transmit the modulated optical signals into the same optical fiber and transmit them to the receiving end in a unidirectional transmission manner; an optical signal analysis module for extracting the optical phase of the optical signal in the receiving end based on autocorrelation technology, and analyzing the distance-resolved vibration signal, vibration amplitude, and vibration frequency; The vibration position calculation module is used to calculate the time difference of the vibration signal according to the distance-resolved vibration signal, the vibration amplitude and the vibration frequency, and calculate the position where the vibration occurs according to the time difference.

9. A terminal, characterized in that: include: A processor and a memory, wherein the memory stores a dispersion-based unidirectional optical fiber communication and distributed sensing deep fusion positioning program, and when the dispersion-based unidirectional optical fiber communication and distributed sensing deep fusion positioning program is executed by the processor, it is used to implement the operation of the dispersion-based unidirectional optical fiber communication and distributed sensing deep fusion positioning method as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a dispersion-based unidirectional optical fiber communication and distributed sensing deep fusion positioning program, which, when executed by a processor, is used to implement the operation of the dispersion-based unidirectional optical fiber communication and distributed sensing deep fusion positioning method as described in any one of claims 1 to 7.

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