A dispersion-based unidirectional optical fiber communication and distributed sensing deep integration positioning method, system, terminal and storage medium

Abstract

The application belongs to the technical field of optical engineering, and discloses a one-way optical fiber communication and distributed sensing deep fusion positioning method and system based on dispersion, a terminal and a storage medium, which comprises the following steps: inputting optical signals of different wavelengths into corresponding modulators respectively, inputting the modulated optical signals into the same optical fiber by using a wavelength division multiplexer, and transmitting the optical signals to a receiving end in a one-way transmission mode; extracting the optical phase of the optical signals in the receiving end based on a self-correlation technology, and analyzing a distance resolution vibration signal, a vibration amplitude and a vibration frequency; calculating a time difference of the vibration signal according to the distance resolution vibration signal, the vibration amplitude and the vibration frequency, and calculating the position where the vibration occurs according to the time difference. By using forward transmission continuous wave light instead of weak backscattering light, the application realizes an ultralong sensing distance, and by adopting self-coherent demodulation, the application can realize vibration positioning without an ultranarrow laser linewidth, thereby reducing the cost and simplifying the positioning mode.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of optical engineering, and particularly relates to a one-way optical fiber communication and distributed sensing deep fusion positioning method, system, terminal and storage medium based on dispersion. BACKGROUND

[0002] Building a widely covered vibration real-time monitoring network can provide better support for disaster warning and decision-making. However, in actual operation, deploying a large-scale sensor array is not only extremely tedious, but also requires high cost.

[0003] Distributed optical fiber sensors provide a new way to solve the above problems due to their high sensitivity, wide dynamic range, strong reliability, spatial resolution information collection capability, and anti-electromagnetic interference. If specific technical means are used to enable the optical fibers in these communication cables to perceive various physical events while performing normal communication functions, achieving integration of sensing and communication, it is expected to quickly build a global information collection network at a lower cost, thereby promoting the development of the next generation of Internet of Things technology. In existing optical fiber sensors, optical frequency domain reflectometry (OFDR) is commonly used for short-distance measurement. Phase-sensitive optical time domain reflectometry (φ-OTDR, also known as distributed acoustic sensing, DAS) focuses on meeting the application scenarios of medium distance and medium spatial resolution, and its maximum sensing distance can reach tens of kilometers without the aid of optical amplifiers. In actual application, both technologies need to add additional hardware devices to effectively collect and process the backscattered light signals. Therefore, the key problems currently faced are concentrated in sensing distance, detection lower limit, and cost.

[0004] A remote sensing system with long sensing optical fibers can significantly reduce the resources, power consumption, and maintenance costs required to support the detection system. If it is organically integrated with existing optical communication systems, the overall cost can be further reduced, and the maintenance workflow can be simplified.

[0005] In existing long-distance distributed sensing technology, forward transmission sensing is a relatively new distributed sensing method, which is substantially different from the common optical backscattering measurement method. This is because the propagation direction of the light signal is similar to optical communication, and existing optical communication systems and light signals can be used without hardware modification. The location of vibration occurrence is calculated by using the characteristics of different wavelengths of light waves having different dispersion. The advantage of this type of technology is that it can be more simply 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 fibers, and lack a universal multi-point vibration positioning method.

[0006] Therefore, the prior art still needs to be improved. SUMMARY

[0007] The technical problem solved by the present application is to provide a one-way optical fiber communication and distributed sensing deep fusion positioning method, system, terminal and storage medium based on dispersion to solve the problems of high cost and complex positioning mode of existing long-distance distributed sensing technology.

[0008] The technical solution adopted by the present application to solve the technical problem is as follows:

[0009] In a first aspect, the present application provides a one-way optical fiber communication and distributed sensing deep fusion positioning method based on dispersion, comprising:

[0010] 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 to the receiving end in a one-way transmission mode;

[0011] Extracting the optical phase of the optical signal in the receiving end based on autocorrelation technology, and analyzing the distance resolution vibration signal, vibration amplitude and vibration frequency;

[0012] 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 where the vibration occurs according to the time difference.

[0013] In an implementation manner, the extracting the optical phase of the optical signal in the receiving end based on autocorrelation technology, and analyzing the distance resolution vibration signal, vibration amplitude and vibration frequency, comprises:

[0014] Separating the optical signals of different wavelengths through a demultiplexer, and inputting the separated optical signals into respective demodulation ends respectively;

[0015] Extracting the optical phase of the corresponding optical signal through the respective demodulation end, and analyzing the distance resolution 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.

[0016] In an implementation manner, the extracting the optical phase of the corresponding optical signal through the respective demodulation end comprises:

[0017] Obtaining the input voltage signal of the photoelectric balance detection module of the demodulation end:

[0018] ;

[0019] ;

[0020] Among them, 、 respectively represent two input voltage signals of the photoelectric balance detection module; , , , represents a constant coefficient; represents a phase of the vibration signal, represents a sum of various types of phase noises;

[0021] high-pass filter the input voltage signals to remove low-frequency direct current components:

[0022] ;

[0023] ;

[0024] perform signal division and arctangent processing according to the filtered voltage signals:

[0025] ;

[0026] calculate the optical phase according to the phase of the vibration signal obtained through the arctangent processing.

[0027] In an implementation manner, the calculating the optical phase according to the phase of the vibration signal obtained through the arctangent processing comprises:

[0028] obtain frequency drift information of the laser:

[0029] ;

[0030] wherein, represents a drift amount of the laser frequency, represents a fiber length, represents a speed of light in a fiber core material;

[0031] calculate the optical phase according to the phase of the vibration signal, the frequency drift information and a communication signal phase:

[0032] ;

[0033] wherein, represents the phase of the vibration signal; represents the communication signal phase; represents the frequency drift information.

[0034] In an implementation manner, the calculating the vibration signal time difference according to the distance resolution vibration signal, the vibration amplitude and the vibration frequency, and calculating the vibration occurrence position according to the vibration signal time difference comprises:

[0035] According to the distance-resolved vibration signal, the vibration amplitude and the vibration frequency, a time difference of the vibration signal is calculated by using a cross-correlation algorithm or a phase spectrum positioning method;

[0036] According to the time difference of the vibration signal, a position where the vibration signal occurs is calculated:

[0037] ;

[0038] wherein, denotes a dispersion coefficient of a preset waveband in a single-mode optical fiber; and respectively denote central wavelengths of two light waves; denotes a time difference between output light signals of different wavelengths caused by dispersion.

[0039] In an implementation manner, the calculating the time difference of the vibration signal according to the distance-resolved vibration signal, the vibration amplitude and the vibration frequency by using the cross-correlation algorithm or the phase spectrum positioning method comprises:

[0040] determining a cross-correlation function:

[0041] ;

[0042] wherein, and respectively denote phase signals demodulated from the light waves of two wavelengths;

[0043] The time difference of the vibration signal is calculated according to the cross-correlation function.

[0044] In an implementation manner, the calculating the time difference of the vibration signal according to the distance-resolved vibration signal, the vibration amplitude and the vibration frequency by using the cross-correlation algorithm or the phase spectrum positioning method further comprises:

[0045] performing Fourier transform on the cross-correlation function:

[0046] wherein, denotes a frequency-domain feature after the Fourier transform;

[0047] amplitude spectrum and phase spectrum of different frequencies are respectively calculated by using the frequency spectrum:

[0048] ;

[0049] ;

[0050] wherein, denotes the amplitude spectrum; denotes the phase spectrum;

[0051] The time delay between different frequencies is calculated according to the phase spectrum:

[0052] ;

[0053] wherein, represents the time difference; represents the vibration frequency.

[0054] In a second aspect, the present application provides a dispersion-based one-way optical fiber communication and distributed sensing deep fusion positioning system, comprising:

[0055] A one-way transmission module is configured to input optical signals of different wavelengths into corresponding modulators respectively, and utilize a wavelength division multiplexer to input the modulated optical signals into the same optical fiber, so as to transmit to a receiving end in a one-way transmission manner.

[0056] An optical signal analysis module is configured to extract optical phases of the optical signals in the receiving end based on an autocorrelation technique, and analyze a distance resolution vibration signal, a vibration amplitude and a vibration frequency.

[0057] A vibration position calculation module is configured to calculate a time difference of the vibration signal according to the distance resolution vibration signal, the vibration amplitude and the vibration frequency, and calculate a position where the vibration occurs according to the time difference.

[0058] In a third aspect, the present application provides a terminal, comprising a processor and a memory, wherein the memory stores a dispersion-based one-way optical fiber communication and distributed sensing deep fusion positioning program, and the dispersion-based one-way optical fiber communication and distributed sensing deep fusion positioning program is used to implement operations of the dispersion-based one-way optical fiber communication and distributed sensing deep fusion positioning method according to the first aspect when executed by the processor.

[0059] In a fourth aspect, the present application further provides a computer readable storage medium, wherein the computer readable storage medium stores a dispersion-based one-way optical fiber communication and distributed sensing deep fusion positioning program, and the dispersion-based one-way optical fiber communication and distributed sensing deep fusion positioning program is used to implement operations of the dispersion-based one-way optical fiber communication and distributed sensing deep fusion positioning method according to the first aspect when executed by a processor.

[0060] The technical solution of the present application has the following effects:

[0061] The application inputs light signals of different wavelengths into corresponding modulators respectively, and uses a wavelength division multiplexer to input the modulated light signals into the same optical fiber, and transmits to the receiving end in a one-way transmission mode; extracts the optical phase of the light signal in the receiving end based on the autocorrelation technology, and analyzes the distance resolution vibration signal, vibration amplitude and vibration frequency; calculates the time difference of the vibration signal according to the distance resolution vibration signal, vibration amplitude and vibration frequency, and calculates the position of vibration occurrence according to the time difference. The application uses forward transmission continuous wave light instead of weak backscattering light, realizes super-long sensing distance, and realizes vibration positioning without ultra-narrow laser linewidth by using self-coherent demodulation, reduces the cost, and simplifies the positioning mode. BRIEF DESCRIPTION OF DRAWINGS

[0062] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from the structures shown in the drawings without creative labor.

[0063] Figure 1 It is a flow chart of the positioning method of the present application based on dispersion of one-way optical fiber communication and distributed sensing.

[0064] Figure 2 It is a structure schematic diagram of the positioning system of the present application based on dispersion of one-way optical fiber communication and distributed sensing.

[0065] Figure 3 It is a functional principle diagram of the terminal in one implementation mode of the present application.

[0066] The purpose of the present application, functional characteristics and advantages will be further described with reference to the drawings. DETAILED DESCRIPTION

[0067] In order to make the purpose, technical scheme and advantages of the present application more clear and definite, the following will further describe the present application with reference to the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application, and are not used to limit the present application.

[0068] Exemplary method

[0069] 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.

[0070] 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.

[0071] 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:

[0072] 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;

[0073] 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.

[0074] 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.

[0075] In this embodiment, based on Figure 2The system shown in the figure, two different wavelengths of light waves are respectively modulated by QPSK (Quadrature Phase Shift Keying, a digital modulation method), and then the communication signals (for example, 1530.334 nm, 1560.606 nm) carried by the WDM (Wavelength Division Multiplexer) enter the same optical fiber, and are transmitted by the same optical fiber to the receiving end.

[0076] Specifically, in an implementation manner of the embodiment, step S200 includes the following steps:

[0077] Step S201, separate the optical signals of different wavelengths by the demultiplexer, and enter the separated optical signals into respective demodulation ends;

[0078] Step S202, extract the optical phase of the corresponding optical signal by the respective demodulation end, and analyze the distance resolution vibration signal, the vibration amplitude and the vibration frequency according to the optical phase to obtain the vibration signal information on the fiber path.

[0079] In the embodiment, the receiving end adopts a self-coherent structure for phase demodulation. At the receiving end, the two different wavelengths of light are separated by the demultiplexer DWDM (Dense Wavelength Division Multiplexing) and enter the respective demodulation ends. After the demodulation system and signal processing and analysis, the vibration signal on the fiber path is obtained to realize sensing.

[0080] In the demodulation end of the vibration signal, the signal light is divided into two paths by the coupler, one path directly enters the mixer, and the other path enters the mixer after being reflected by the Faraday rotator (FRM) and passing through the delay optical fiber, serving as the intrinsic light in the interference. The four signals output by the mixer are 0° signal, 90° signal, 180° signal and 270° signal. The 0° signal and the 180° signal are connected to a BPD module (i.e., a first optical balanced detection module), and the 90° signal and the 270° signal are connected to another BPD module (i.e., a second optical balanced detection module), so as to eliminate the influence of the direct current component. Finally, the vibration phase can be obtained by collecting the voltage signals output by the two BPD modules and using the phase demodulation method.

[0081] In the embodiment, after the optical phase of the corresponding optical signal is extracted by the respective demodulation end, the distance resolution vibration signal, the vibration amplitude and the vibration frequency can be analyzed according to the optical phase, so as to obtain the vibration signal information on the fiber path.

[0082] Different from the traditional double optical path structure, only one optical path for unidirectional transmission is used in the sensing structure of the embodiment, and different wavelengths of light are propagated in the same optical fiber by using wavelength division multiplexing technology. When a disturbance occurs on the optical fiber path, the phases of different wavelengths of light waves will change, but due to the dispersion effect, different wavelengths of light propagate at different speeds, and the time of arrival of the phase change caused by the disturbance at the receiving end is also different. The farther the vibration position is from the detector at the receiving end, the greater the time delay generated. For example, when two light waves with a wavelength difference of 30 nm are used, a disturbance occurs at a distance of 50 km from the detector, and then a high sampling rate oscilloscope is used to collect signals and further analyze the signals to obtain a time delay of 24 ns. If the disturbance occurs at a distance of 100 km, the time delay generated is 48 ns, and the position of the disturbance can be obtained by detecting the time delay.

[0083] Specifically, in an implementation manner of the embodiment, step S201 includes the following steps:

[0084] Step S201a, obtaining an input voltage signal of an optoelectronic balance detection module of the demodulation end;

[0085] Step S201b, high-pass filtering the input voltage signal to remove low-frequency direct current components;

[0086] Step S201c, performing signal division and arctangent processing according to the filtered voltage signal;

[0087] Step S201d, calculating the optical phase according to the phase of the vibration signal obtained by the arctangent processing.

[0088] In the embodiment, for the demodulation end of one wavelength, the input voltage signal of the corresponding BPD module can be represented as:

[0089] ;

[0090] ;

[0091] wherein, 、 are two input voltage signals of the optoelectronic balance detection module; , , , is a constant coefficient; is the phase of the vibration signal, is the sum of various phase noises.

[0092] In actual scenarios, , , , may be a coefficient determined by some low-frequency components, phase mismatch, responsivity of the photodiode, and 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 completely the same, b and d can be approximately considered equal.

[0093] After obtaining the input voltage signal of the BPD module, the signal is high-pass filtered to remove the low-frequency DC component:

[0094]

[0095]

[0096] Subsequently, the signal is divided and the arctangent processing is performed according to ,

[0097]

[0098] After that, the phase of the vibration signal obtained by the arctangent processing can be used to calculate the optical phase.

[0099] In this embodiment, the optical phase is calculated according to the phase of the vibration signal obtained by the arctangent processing, including the following steps: obtaining frequency drift information of the laser; calculating the optical phase according to the phase of the vibration signal, the frequency drift information, and the phase of the communication signal.

[0100] It is worth noting that when combined with an optical communication system, unlike expensive narrow-linewidth lasers, the laser used in this embodiment will often have a certain frequency drift, and the impact it brings will be directly reflected in the demodulated phase; therefore, the frequency drift information of the laser needs to be determined:

[0101]

[0102] wherein, represents the amount of drift of the laser frequency, represents the length of the optical fiber, represents the speed of light in the core material of the optical fiber.

[0103] Moreover, since the communication signal and the vibration signal are both transmitted by the phase of the light wave, the demodulated phase signal will often be affected by the communication signal, that is, the communication signal itself can be regarded as a kind of noise for the vibration signal. Therefore, the demodulated phase is actually the sum of the phase of the vibration signal, the phase of the communication signal, and the phase fluctuation caused by the frequency drift of the laser:

[0104] ;​​​​​

[0105] wherein, denotes the phase of the vibration signal; denotes the phase of the communication signal; denotes the frequency drift information.

[0106] The three signals are mutually independent and have obvious distinction in the frequency domain, so that the phase signal of the vibration can be extracted by band-pass filtering the frequency range where the vibration signal is expected to be located. Then, the time delay of the phases of the two light waves can be obtained by using a positioning method such as cross-correlation or phase spectrum.

[0107] In this embodiment, the phase demodulation for another wavelength also adopts the extraction scheme of the optical phase of the light signal as described above.

[0108] As Figure 1 shown, the embodiment of the present application provides a dispersion-based one-way optical fiber communication and distributed sensing deep integration positioning method, comprising the following steps:

[0109] Step S300, 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.

[0110] In this embodiment, the dispersion-based positioning method is used to calculate the time difference of the vibration signal, and the position where the vibration occurs is calculated according to the time difference.

[0111] Specifically, in one implementation manner of the embodiment, step S300 comprises the following steps:

[0112] Step S301, 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;

[0113] Step S302, calculating the position where the vibration signal occurs according to the time difference of the vibration signal.

[0114] In this embodiment, when light is transmitted in an optical fiber, not only will the light power be attenuated due to the loss of the optical fiber itself, but also the walk-off phenomenon between light waves of different wavelengths will occur due to the dispersion effect. Therefore, the dispersion-based positioning method is used to locate the position where the vibration occurs; wherein the dispersion is usually represented by the dispersion coefficient, with the unit of ps / (nm·km). For a single-mode optical fiber, there is no modal dispersion due to single-mode transmission. The main reason for causing the walk-off is material dispersion.

[0115] Specifically, the material dispersion is caused by the nonlinear change of the refractive index of the optical fiber material with the wavelength of the light wave. For a single-mode quartz optical fiber, it can be represented as:

[0116] ;

[0117] wherein, is the refractive index of the medium, is the wavelength of the light wave, is the speed of light in vacuum; the refractive index of quartz varies with the change of wavelength, which is essentially due to the interaction of light wave and quartz electronic vibration, resulting in different propagation speed of light of different wavelengths in the material. Vibration occurs along the long sensing optical fiber, and the time delay of the vibration signal from the vibration position to the two photodetectors is determined by the dispersion coefficient corresponding to the respective wavelength and the propagation distance. The time delay can be obtained by further analyzing the signal, and the disturbance position can be obtained.

[0118] In this embodiment, two continuous lasers with center wavelengths of 1530.334 nm (195.9 THz) and 1560.606 nm (192.1 THz) are used. When they propagate in the optical fiber, the propagation speed of the light signals of the two wavelengths will be different due to dispersion. On this basis, when a disturbance occurs on the optical fiber path, the phase change produced will also be different, and in addition to the time delay caused by fiber dispersion, the interference patterns detected by the two photodetectors of different wavelengths are almost the same. The walk-off effect between the output light signals of the two different wavelengths caused by dispersion can be expressed as wherein, represents the dispersion coefficient in the optical fiber, represents the length of the optical fiber.

[0119] At this time, the position of the disturbance can be calculated according to the time difference of the phase signals demodulated at the receiving end. The position of the vibration signal can be determined by the following formula:

[0120] ;

[0121] wherein, represents the dispersion coefficient of the preset wavelength band in the single-mode optical fiber, and the value is 16 ps / nm·km; and represent the center wavelengths of the two light waves, respectively; represents the time difference between the output light signals of different wavelengths caused by dispersion. In general, the core of vibration positioning is to detect the time delay of the two phase signals .

[0122] In the embodiment, after the phase signals corresponding to the two wavelengths are demodulated respectively at two demodulation ends, the time difference of the vibration signal is calculated by using a cross-correlation algorithm or a phase spectrum positioning method.

[0123] Specifically, in an implementation of the embodiment, step S301 includes the following steps.

[0124] Step S301a, determining a cross-correlation function.

[0125] Step S301b, calculating the time difference of the vibration signal according to the cross-correlation function.

[0126] In the embodiment, after the phase signals corresponding to the two wavelengths are demodulated respectively at two demodulation ends, the similarity between the two signals and the time offset relationship thereof are analyzed. The time delay can be obtained by using a cross-correlation algorithm or a phase spectrum algorithm.

[0127] The cross-correlation algorithm finds the time point corresponding to the peak value of the cross-correlation function by calculating the cross-correlation function of the two signals, and the time point represents the time delay between the two signals. The cross-correlation function is defined as:

[0128] ;

[0129] wherein, and respectively represent the phase signals demodulated from the light waves of the two wavelengths.

[0130] Since the two signals are completely consistent in waveform, when the time delay is the actual time delay of the signals, the function takes the maximum value. At this time, is the time delay of the two signals. In the case of single-point vibration, the cross-correlation algorithm can directly obtain the time delay of the signal.

[0131] Specifically, in an implementation of the embodiment, step S301 further includes the following steps.

[0132] Step S301c, performing Fourier transform on the cross-correlation function.

[0133] Step S301d, calculating the amplitude spectrum and the phase spectrum of different frequencies by using the frequency spectrum.

[0134] Step S301e, calculating the time delay between different frequencies according to the phase spectrum.

[0135] In the embodiment, the phase spectrum method is to perform Fourier transform on the cross-correlation function on the basis of the cross-correlation algorithm, and then analyze in the frequency domain.

[0136] Therefore, the cross-correlation function is first Fourier transformed:

[0137] wherein, represents the frequency domain feature after Fourier transform;

[0138] Then, the amplitude spectrum and the phase spectrum of different frequencies are calculated by the frequency spectrum respectively:

[0139]

[0140]

[0141] wherein, represents the amplitude spectrum; represents the phase spectrum;

[0142] Therefore, the time delay between different frequencies for the phase spectrum can be represented as:

[0143]

[0144] wherein, represents the time difference; represents the vibration frequency.

[0145] In the embodiment, the phase spectrum method can realize the time delay of different frequency components of the signal respectively, and when the vibration signals at different positions can be distinguished in frequency, the method can be used to realize the detection of multi-point vibration.

[0146] In the embodiment, the time difference of the vibration signal is calculated by the above two methods, and according to the time difference of the vibration signal, the formula can be used to calculate the position where the vibration signal occurs.

[0147] In the embodiment, a new type of optical fiber acoustic sensor or vibration sensor based on dispersion is applied, which can realize a sensing range of at least 150 kilometers without an optical amplifier. The optical phase is extracted by the autocorrelation technology, the distance resolution vibration signal and the vibration amplitude and frequency are analyzed, and then the position where the vibration occurs is calculated by the time difference. When analyzing the signal at the receiving end, the cross-correlation spectrum is used for FFT (Fourier) transform, so as to obtain the phase spectrum, and then estimate the vibration position source of each frequency component. The sensing mode in the embodiment has many advantages. Among them, including:

[0148] 1) Higher signal-to-noise ratio (optical power is several orders of magnitude higher than backscattered light), which is not affected by Rayleigh backscattering noise;

[0149] 2) Less nonlinear effect (continuous wave light); ​​​

[0150] 3) Longer sensing distance to avoid optical amplifiers (easier to install and maintain);

[0151] 4) Spatial resolution is not directly related to sensing range (allows separate optimization without trade-off);

[0152] 5) Unlike two-end OTDR (optical time domain reflectometry) systems, there is no weak SNR (signal-to-noise ratio) region in the middle of the sensing fiber.

[0153] 6) Can be directly integrated with fiber communication systems without using dark fibers or other additional hardware facilities.

[0154] 7) All demodulation devices are placed on one side, facilitating time synchronization.

[0155] As an alternative to the present embodiment, the detection frequency range of the distributed vibration fiber sensor of the present embodiment can be adaptively changed, the detection distance can be adaptively changed; the type of optical fiber can be changed, which can be replaced by a special fiber sensitive to vibration, or other types of optical fiber, such as multi-core optical fiber, polarization maintaining optical fiber, etc. The wavelength range of the laser can also be changed. In addition, different demodulation methods can be applied, such as heterodyne IQ demodulation (a signal processing technique), etc. In addition, other properties of light waves can also be used for sensing under the condition of sacrificing certain positioning accuracy, such as polarization state.

[0156] The technical effects achieved by the technical solutions of the present embodiment are as follows:

[0157] The present embodiment utilizes the dispersion effect of the optical fiber to realize the detection of the phase change along a single optical fiber and the positioning of the vibration, and is deeply combined with the optical communication system; and by using forward transmission continuous wave light instead of weak backscattered light, an ultra-long sensing distance is realized, and by using self-coherent demodulation, vibration positioning can be realized without ultra-narrow laser linewidth, thereby reducing the cost and simplifying the positioning method; the sensing system used in the present embodiment can be directly combined with the existing optical communication system without the need for additional dark fibers, and can be directly deployed on the existing optical communication system to realize communication and sensing integration.

[0158] Exemplary apparatus

[0159] Based on the above-mentioned embodiments, the present application further provides a one-way fiber communication and distributed sensing deep integration positioning system based on dispersion, comprising:

[0160] A one-way transmission module is used to input optical signals of different wavelengths into corresponding modulators respectively, and to input the modulated optical signals into the same optical fiber by using a wavelength division multiplexer, so as to be transmitted to a receiving end in a one-way transmission manner.

[0161] an optical signal analysis module configured to extract an optical phase of the optical signal in the receiving end based on a self-correlation technique, and analyze a distance-resolved vibration signal, a vibration amplitude, and a vibration frequency;

[0162] a vibration position calculation module configured to calculate a time difference of the vibration signal according to the distance-resolved vibration signal, the vibration amplitude, and the vibration frequency, and calculate a position where the vibration occurs according to the time difference.

[0163] The embodiment achieves the following technical effects through the above technical solutions:

[0164] The embodiment utilizes the dispersion effect of the optical fiber to realize detection of phase changes along a single optical fiber and positioning of vibration, and is deeply combined in an optical fiber communication system. Moreover, by using forward transmission continuous wave light instead of weak backscattering light, a super-long sensing distance is realized, and by using self-coherent demodulation, vibration positioning can be realized without a super-narrow laser line width, thereby reducing the cost and simplifying the positioning mode. The sensing system used in the embodiment can be directly combined with an existing optical communication system, without the need for additional reserved dark optical fibers, and can be directly deployed on the existing optical communication system to realize communication and sensing integration.

[0165] Based on the above embodiment, the application further provides a terminal, a principle block diagram of which can be as shown in Figure 3 .

[0166] The terminal includes a processor, a memory, an interface, a display screen, and a communication module connected through a system bus. The processor of the terminal is configured 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 running the operating system and the computer program in the computer readable storage medium. The interface is configured to connect external devices. The display screen is configured to display corresponding information. The communication module is configured to communicate with a cloud server or other devices.

[0167] The computer program is executed by the processor to implement the operation of the dispersion-based one-way optical fiber communication and distributed sensing deep integration positioning method.

[0168] Those skilled in the art can understand that, Figure 3 The principle block diagram shown in the above

[0169] In one embodiment, a terminal is provided, comprising: a processor and a memory, the memory storing a dispersion-based one-way optical fiber communication and distributed sensing deep fusion positioning program, the dispersion-based one-way optical fiber communication and distributed sensing deep fusion positioning program, when executed by the processor, being configured to implement the operations of the dispersion-based one-way optical fiber communication and distributed sensing deep fusion positioning method as described above.

[0170] In one embodiment, a computer readable storage medium is provided, wherein the computer readable storage medium stores a dispersion-based one-way optical fiber communication and distributed sensing deep fusion positioning program, the dispersion-based one-way optical fiber communication and distributed sensing deep fusion positioning program, when executed by a processor, being configured to implement the operations of the dispersion-based one-way optical fiber communication and distributed sensing deep fusion positioning method as described above.

[0171] It can be understood by those skilled in the art that all or part of the processes in the above-mentioned embodiments can be completed by a computer program instructing related hardware, and the computer program can be stored in a non-volatile storage medium. When the computer program is executed, it can include the processes of the above-mentioned embodiments. Any reference to memory, storage, database or other medium used in the embodiments provided by the present application can include non-volatile and volatile memory.

[0172] In summary, the present application provides a dispersion-based one-way optical fiber communication and distributed sensing deep fusion positioning method, system, terminal and storage medium, comprising: 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 to the receiving end in a one-way transmission manner; extracting the optical phase of the optical signal in the receiving end based on the autocorrelation technology, and analyzing the distance resolution vibration signal, vibration amplitude and vibration frequency; 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 where the vibration occurs according to the time difference. The present application uses forward transmission continuous wave light instead of weak backscattering light, realizes ultra-long sensing distance, and uses self-coherent demodulation, realizes vibration positioning without ultra-narrow laser linewidth, reduces cost and simplifies positioning method.

[0173] It should be understood that the application of the present application is not limited to the above examples, and those skilled in the art can make improvements or changes according to the above description, and all these improvements and changes shall belong to the protection scope of the appended claims of the present application.

Claims

1. A dispersion-based unidirectional fiber-optic communication and distributed sensing deep fusion positioning method, characterized in that, The application relates to a method for transmitting vibration signal information on a fiber path. The method comprises the following steps: The light signals of different wavelengths are input into corresponding modulators respectively, and the modulated light signals are input into the same optical fiber by using a wavelength division multiplexer, and are transmitted to a receiving end in a one-way transmission mode; The optical phase of the light signal in the receiving end is extracted based on a self-correlation technology, and vibration signal information on the fiber path is obtained by analyzing a distance resolution vibration signal, a vibration amplitude and a vibration frequency according to the optical phase; The light signals of different wavelengths are separated by using a wavelength division demultiplexer, and the separated light signals are respectively input into corresponding demodulation ends; ； ； wherein, , represent two input voltage signals of the optical balance detection module, respectively; , , , represents a constant coefficient; represents a phase of the vibration signal, represents a sum of various phase noises; The optical phase of the corresponding light signal is extracted by using the corresponding demodulation end, which comprises the following steps: ； ； An input voltage signal of a photoelectric balance detection module of the demodulation end is obtained; ； The input voltage signal is high-pass filtered to remove low-frequency direct current components; Signal division and arctangent processing are performed according to the filtered voltage signal; The optical phase is calculated according to the phase of the vibration signal obtained by the arctangent processing, which comprises the following steps: The frequency drift information of the laser is obtained, and the optical phase is calculated according to the phase of the vibration signal, the frequency drift information and a communication signal phase; ； wherein, represents the occurrence position of the vibration signal; represents the dispersion coefficient of a preset wavelength band in the single-mode optical fiber; and respectively represent the center wavelengths of the two light waves; represents the time difference between the output light signals of different wavelengths caused by dispersion.

2. The dispersion-based one-way fiber-optic communication and distributed sensing deep fusion positioning method according to claim 1, characterized in that, The time difference of the vibration signal is calculated according to the distance resolution vibration signal, the vibration amplitude and the vibration frequency, and the position of the vibration is calculated according to the time difference, which comprises the following steps: ； wherein, represents the amount of drift of the laser frequency, represents the length of the optical fiber, represents the speed of light in the core material of the optical fiber; After the phase signals corresponding to different wavelengths are demodulated respectively at the demodulation end according to the distance resolution vibration signal, the vibration amplitude and the vibration frequency, the time difference of the vibration signal is calculated by using a cross-correlation algorithm or a phase spectrum positioning method; the cross-correlation algorithm finds the time point corresponding to the peak value of the function by calculating the cross-correlation function of two signals, and the time point represents the time delay between the two signals; the phase spectrum positioning method is to perform Fourier transform on the cross-correlation function on the basis of the cross-correlation algorithm, and then calculate the time difference according to the phase spectrum in the frequency domain; ； wherein denotes a phase of the vibration signal; denotes a phase of the communication signal; denotes the frequency drift information.

3. The dispersion-based one-way fiber-optic communication and distributed sensing deeply integrated positioning method according to claim 1, characterized in that, The frequency drift information is as follows: The optical phase is as follows: ； wherein with respectively represent phase signals demodulated from light waves of two wavelengths; The time difference of the vibration signal is calculated according to the distance resolution vibration signal, the vibration amplitude and the vibration frequency by using the cross-correlation algorithm or the phase spectrum positioning method, which comprises the following steps:

4. The dispersion-based one-way fiber-optic communication and distributed sensing deeply integrated positioning method according to claim 3, characterized in that, The cross-correlation function is determined; The time difference of the vibration signal is calculated according to the cross-correlation function; the time difference is the cross-correlation function of the phase signals demodulated from the light waves of two wavelengths, and the time point corresponding to the peak value of the function is found, which represents the time delay between the phase signals demodulated from the light waves of two wavelengths. ; wherein, denotes the frequency domain feature after Fourier transform; The time difference of the vibration signal is calculated according to the distance resolution vibration signal, the vibration amplitude and the vibration frequency by using the cross-correlation algorithm or the phase spectrum positioning method, which further comprises the following steps: ； ； wherein represents the amplitude spectrum; represents the phase spectrum; The Fourier transform is performed on the cross-correlation function; ； wherein represents the time difference; represents the vibration frequency.

5. A dispersion-based one-way fiber-optic communication and distributed sensing deep fusion positioning system for implementing the dispersion-based one-way fiber-optic communication and distributed sensing deep fusion positioning method according to any one of claims 1-4, characterized in that, The amplitude spectrum and the phase spectrum of different frequencies are calculated respectively by using the frequency spectrum; The time delay between different frequencies is calculated according to the phase spectrum; The application relates to a method for transmitting vibration signal information on a fiber path. The one-way transmission module is used for inputting the light signals of different wavelengths into corresponding modulators respectively, and inputting the modulated light signals into the same optical fiber by using a wavelength division multiplexer, and transmitting the light signals to a receiving end in a one-way transmission mode. The optical signal analysis module is configured to extract the optical phase of the optical signal in the receiving end based on the autocorrelation technique, and analyze the distance-resolved vibration signal, the vibration amplitude, and the vibration frequency. The vibration position calculation module is configured 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.

6. A terminal, characterized by comprising: The method comprises the following steps: The processor and the memory, wherein the memory stores a dispersion-based one-way optical fiber communication and distributed sensing deep fusion positioning program, and the dispersion-based one-way optical fiber communication and distributed sensing deep fusion positioning program is used to implement the operations of the dispersion-based one-way optical fiber communication and distributed sensing deep fusion positioning method according to any one of claims 1-4 when executed by the processor.

7. A computer readable storage medium characterized in that, The computer readable storage medium stores a dispersion-based one-way optical fiber communication and distributed sensing deep fusion positioning program, and the dispersion-based one-way optical fiber communication and distributed sensing deep fusion positioning program is used to implement the operations of the dispersion-based one-way optical fiber communication and distributed sensing deep fusion positioning method according to any one of claims 1-4 when executed by the processor.

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