Time division multiplexing type high signal-to-noise ratio pipeline anti-damage real-time monitoring method and device
Through time division multiplexing Michaelson interferometer sensor array and dual-wavelength technology, the problem of high construction difficulty and high cost in pipeline monitoring is solved, real-time monitoring of pipeline damage with high signal-to-noise ratio is achieved, and monitoring sensitivity and signal accuracy are improved.
Patent Information
- Application Number
- CN202510610944.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-13
- Publication Date
- 2025-08-12
AI Technical Summary
The existing distributed fiber optic sensing technology requires the laying of optical cables along the pipeline during pipeline monitoring. The construction is difficult and costly, and is not suitable for the monitoring needs of laid oil and gas pipelines.
The time division multiplexing high sensitivity Michaelson interferometer sensor array combines rectangular pulse binary phase modulation and dual-wavelength technology to achieve real-time monitoring of pipeline damage prevention with high signal-to-noise ratio, and restore phase signals through virtual synthesis wavelengths to avoid signal distortion.
Efficient monitoring along the pipeline is achieved, avoiding the problems of difficult and high cost of construction, and improving the sensitivity and signal-to-noise ratio of the sensing unit to ensure signal accuracy.
Smart Images
Figure CN120467604A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of optical fiber sensing, and in particular relates to a time-division multiplexing high signal-to-noise ratio pipeline anti-destruction real-time monitoring method and device. Background Art
[0002] Fiber-optic sensing technology uses optical fiber as a sensor to measure physical quantities such as pressure, temperature, vibration, and displacement. It has been widely used in military, defense, and civilian applications, safeguarding national security, stability, and economic development. Pipeline transportation is one of the five major modern transportation modes (road, rail, water, aviation, and pipeline). Compared to the other four modes, pipeline transportation offers unique advantages: it is a continuous and efficient method; pipelines are generally buried underground, unrestricted by external conditions; they are less likely to cause environmental and noise pollution; and transportation costs are low. As pipelines age, they inevitably experience wear and corrosion. This, combined with third-party sabotage, leads to frequent pipeline leakage accidents. Third-party sabotage has increasingly become a major cause. Therefore, research on pipeline anti-sabotage monitoring technology is of great significance.
[0003] In recent years, fiber optic sensors have gradually demonstrated unique advantages in detecting physical quantities such as vibration, pressure, and temperature. Optical fiber serves as both a sensing and transmission medium, greatly simplifying the structure of the sensing system and making it suitable for a variety of spatial environments. Various distributed fiber optic sensing technologies have been widely used in pipeline monitoring. However, these technologies require laying fiber optic cables along the pipeline as sensing units. While these technologies offer high positioning accuracy, the construction of excavating the ground along the pipeline and laying fiber optic cables along the pipeline is difficult and costly, making them unsuitable for some practical applications. Summary of the Invention
[0004] Purpose of the Invention: This invention aims to provide a time-division multiplexed, high-signal-to-noise ratio, real-time pipeline anti-vandalism monitoring method and apparatus. This method utilizes a time-division multiplexed, high-sensitivity, single-point interferometric fiber optic sensor array to achieve regional monitoring, thus covering the entire pipeline. Rectangular pulse binary phase modulation combined with dual-wavelength technology achieves high signal-to-noise ratio detection for highly sensitive sensing units, effectively preventing signal distortion.
[0005] Technical solution: A time-division multiplexing high signal-to-noise ratio pipeline anti-destruction real-time monitoring method of the present invention comprises the following steps:
[0006] Step 1: Turn on the first laser and the second laser. The lasers emitted by the first laser and the second laser are coupled through a first wavelength division multiplexer to form a dual-wavelength laser, i.e., the wavelength of the first laser and the wavelength of the second laser. The dual-wavelength laser then passes through an acousto-optic modulator, a phase modulator, and a circulator into the telemetry optical fiber. The data control and acquisition module drives the acousto-optic modulator through the voltage amplification module and simultaneously generates a phase modulation signal to act on the phase modulator.
[0007] Step 2: The phase-modulated dual-wavelength laser is split into N paths by a coupler through the telemetry fiber and then enters the time-division multiplexing Michelson interferometer array through the delay fiber. The interference signal reflected back by each sensor unit on the pipeline surface passes through the coupler. The optical signal carrying the sensor information from the telemetry fiber returns to the circulator and enters the second wavelength division multiplexer for separation by wavelength, and then enters the corresponding photodetector. The data control and acquisition module receives the electrical signals converted by each photodetector, extracts the light intensity signal, and transmits the phase-shifted interference signal to the host computer feedback software.
[0008] Step 3: The electrical signal of step 2 is subjected to the delay of the calibrated interference light intensity signal and the modulated pulse signal to obtain a three-step phase shift signal;
[0009] Step 4: Based on the three-step phase-shifted signal, the inverse tangent method is used to obtain the wrapped phases corresponding to the wavelength of the first laser and the wavelength of the second laser respectively. After unwrapping the wrapped phases, the real phase corresponding to the wavelength of the first laser is obtained, thereby obtaining the final real phase information.
[0010] Furthermore, in step 1, the wavelength λ1 of the first laser is smaller than the wavelength λ2 of the second laser, and the phase modulator makes the phase modulation amount generated by each pulse in a pulse sequence be [π / 2; -π / 2, 0] respectively.
[0011] Furthermore, in step 2, the light intensity signal is extracted as follows:
[0012] The interference light intensity of the nth sensing channel corresponding to different wavelengths at a certain vibration point on the telemetry optical fiber extracted by the data control acquisition module can be expressed as:
[0013]
[0014] Where A and B are proportional to the input light intensity, and B = κA, κ ≤ 1 is the visibility of the interference fringes; is the final phase modulation term, satisfying is the phase modulation amount produced by the phase modulator, and τ is the delay produced by the laser passing through the two arms of the interferometer; Specifically, it can be expressed as:
[0015]
[0016] Where k is an integer and T is the period of the modulation signal;
[0017] From formula (2), we can get Substituting into formula (1) we can get:
[0018]
[0019] Furthermore, step 3 is specifically as follows: the data control acquisition module collects the corresponding electrical signal, and obtains 2n groups of corresponding three-step phase shift signals by calibrating the delay of the interference light intensity signal and the modulated pulse signal, which can be specifically expressed as:
[0020]
[0021] Furthermore, step 4 is specifically as follows: the host computer feedback software receives the 2n groups of three-step phase shift signals extracted by the data control acquisition module, and the host computer feedback software uses the inverse tangent method to obtain the package phase θ corresponding to the wavelength λ1 of the first laser and the wavelength λ2 of the second laser respectively. n1wrap (t) and θ n2wrap (t), and the difference between the two is obtained, that is, the wrapping phase θ corresponding to the synthetic wavelength nwrap (t) = θ n1wrap (t)-θ n2wrap (t); for θ nwrap (t) is unwrapped to obtain θ n (t), and then multiply it by the coefficient λ2 / (λ2-λ1) to obtain the true phase corresponding to the wavelength λ1, thereby obtaining the final true phase information.
[0022] Furthermore, the 2n groups of three-step phase shift signals are I 1,n1 (t), I 1,n2 (t), I 1,n3 (t), I 2,n1 (t), I 2,n2 (t), I 2,n3 (t); The inverse tangent method obtains the corresponding 2n sets of wrapped phases as follows:
[0023]
[0024] The difference between the phase signals corresponding to the two wavelengths is obtained to obtain the wrapping phase θ of the equivalent wavelength. nwrap (t):
[0025] θ nwrap (t) = θ n1wrap (t)-θ n2wrap (t)(6)
[0026] The phase θ of the equivalent synthetic wavelength nwrap (t) is unwrapped to obtain the phase θn (t), and obtain the true phase information corresponding to wavelength λ1:
[0027] θ n1 (t) = θ n (t)·λ2 / λ2-λ1(7)
[0028] The present invention also discloses a device for a time-division multiplexing, high-signal-to-noise ratio, real-time pipeline anti-destruction monitoring method. The device comprises a first laser, a second laser, a first wavelength division multiplexer, an acousto-optic modulator, a phase modulator, a circulator, a telemetry fiber, a 1xN coupler, a Michelson interferometer array, a pipeline, a delayed transmission fiber, a second wavelength division multiplexer, a photodetector, a data control and acquisition module, a voltage amplifier module, and host computer feedback software. The first laser and the second laser are respectively connected to the first wavelength division multiplexer via optical fibers. The ports of the first wavelength division multiplexer, the acousto-optic modulator, the phase modulator, and the circulator are sequentially connected via optical fibers. The ports of the circulator are connected to the telemetry fiber via optical fibers. The telemetry fiber is connected to the 1xN coupler, the delayed transmission fiber, the Michelson interferometer array, and the pipeline via optical fibers. The ports of the circulator, the second wavelength division multiplexer, and the photodetector are connected via optical fibers. The data control and acquisition module is respectively connected to the photodetector, the voltage amplifier module, the phase modulator, and the host computer feedback software.
[0029] The laser light emitted by the first and second lasers sequentially passes through a first wavelength division multiplexer, an acousto-optic modulator, and a phase modulator. The data processing module generates pulse-modulated and phase-modulated signals, providing the pulse-modulated signal to the acousto-optic modulator through a voltage amplifier module while simultaneously providing phase modulation to the phase modulator, forming a phase-modulated pulse train. This phase-modulated pulse train passes through a circulator into a telemetry fiber. Then, through a 1xN coupler and a time-delay fiber, it enters a time-division multiplexed Michelson interferometer array equally spaced on the pipeline surface. The Michelson interferometers form highly sensitive vibration sensors and are equally spaced on the pipeline arms; the telemetry fiber and the time-delay fiber are located on the surface. The optical signal returning from the pipeline surface passes through the Michelson interferometer array, the time-delay fiber, the 1xN coupler, and the telemetry fiber into the circulator. It then passes through a second wavelength division multiplexer and enters the corresponding photodetector for photoelectric conversion. The data control and acquisition module collects the electrical signals, processes them, and transmits them to the host computer software. The upper computer software demodulates each group of three-step phase-shifted signals to obtain each group of wrapped phase signals. At the same time, it uses the wavelengths of the first laser and the second laser to construct an equivalent synthetic wavelength to obtain the final unwrapped phase, thereby achieving high signal-to-noise ratio detection of the high-sensitivity sensing unit and effectively avoiding signal distortion.
[0030] Furthermore, the first laser and the second laser are coupled via a first wavelength division multiplexer, and the interference light intensity signals corresponding to the wavelength λ1 and the wavelength λ2 are separated via a second wavelength division multiplexer.
[0031] Furthermore, the Michelson interferometer array constitutes a high-sensitivity vibration sensor, which is evenly spaced and affixed to the surface of the pipeline; the telemetry optical fiber and the delay optical fiber are located on the surface.
[0032] Furthermore, the data control acquisition module generates a modulation signal, provides a pulse modulation signal to the acousto-optic modulator through the voltage amplification module, and provides phase modulation to the phase modulator at the same time.
[0033] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages:
[0034] (1) The present invention constructs a time-division multiplexing high signal-to-noise ratio pipeline anti-destruction real-time monitoring method, which utilizes a time-division multiplexing high-sensitivity Michelson interferometer sensor array to achieve regional monitoring, thereby covering the entire pipeline line, and ultimately solving the problem of the difficulty and high cost of excavating the pipeline and laying optical fiber cables along the pipeline;
[0035] (2) The present invention constructs a time-division multiplexing high signal-to-noise ratio real-time monitoring device for pipeline anti-destruction, which uses rectangular pulse binary phase modulation combined with dual-wavelength technology to achieve high signal-to-noise ratio detection of high-sensitivity sensing units. The phase signal is restored by a virtual synthetic wavelength constructed by two sets of different wavelengths, and the real phase information can be obtained for feedback wavelength tuning control, effectively avoiding signal distortion. BRIEF DESCRIPTION OF THE DRAWINGS
[0036] Figure 1 The figure is a schematic diagram of the device structure of a time-division multiplexing high signal-to-noise ratio pipeline anti-destruction real-time monitoring method of the present invention.
[0037] Figure 2 This is a sensor placement diagram for a time-division multiplexing high signal-to-noise ratio pipeline anti-destruction real-time monitoring method and device of the present invention.
[0038] Figure 3 This is a signal extraction flow chart of a time-division multiplexing high signal-to-noise ratio pipeline anti-destruction real-time monitoring method of the present invention. DETAILED DESCRIPTION
[0039] The technical solution of the present invention will be further described below with reference to the accompanying drawings.
[0040] Combine Figure 1 A time-division multiplexing high signal-to-noise ratio pipeline anti-destruction real-time monitoring method and device, the method steps are as follows:
[0041] Step 1: Turn on the first and second lasers. The lasers emitted by the first and second lasers are coupled through the first wavelength division multiplexer to form a dual-wavelength laser. λ1 is the wavelength of the first laser, and λ2 is the wavelength of the second laser, satisfying λ1 < λ2. This dual-wavelength laser then passes through an acousto-optic modulator, a phase modulator, and a circulator into the telemetry fiber. The data control and acquisition module drives the acousto-optic modulator through the voltage amplifier module, simultaneously generating a phase modulation signal that acts on the phase modulator. The phase modulation amount is [0, π / 2].
[0042] Step 2: The phase-modulated dual-wavelength laser beam passes through the telemetry fiber, split into N paths by a 1xN coupler, and then enters a highly sensitive time-division multiplexed Michelson interferometer array via a time-delayed fiber. The interference signal reflected from each sensor unit on the pipeline surface passes through a 1xN coupler. The optical signal carrying the sensor information from the telemetry fiber returns to the circulator, enters a second wavelength division multiplexer, and is separated by wavelength before entering the corresponding photodetector. The data control and acquisition module receives the electrical signals converted by each photodetector, extracts the light intensity signal, and transmits the phase-shifted interference signal to the host computer feedback software.
[0043] The interference light intensity of the nth sensing channel corresponding to different wavelengths at a certain vibration point on the telemetry optical fiber extracted by the data control acquisition module can be expressed as:
[0044]
[0045] Where A and B are proportional to the input light intensity, and B = κA, κ ≤ 1 is the visibility of the interference fringes; is the final phase modulation term, satisfying is the phase modulation amount generated by the phase modulator, and τ is the delay generated when the laser passes through each sensor array; Specifically, it can be expressed as:
[0046]
[0047] Where k is an integer and T is the period of the modulation signal;
[0048] From formula (2), we can get Substituting into formula (1) we can get:
[0049]
[0050] Step 3: The data control acquisition module collects the corresponding electrical signals. By calibrating the delay between the interference light intensity signal and the modulated pulse signal, 2n groups of corresponding three-step phase shift signals are obtained from formula (3), which can be specifically expressed as:
[0051]
[0052] Step 4: The host computer feedback software receives the 2n groups of three-step phase shift signals extracted by the data control acquisition module, and uses the inverse tangent method to obtain the package phase θ corresponding to λ1 and λ2 respectively. n1wrap (t) and θ n2wrap (t), and the difference between the two is obtained, that is, the wrapping phase θ corresponding to the synthetic wavelength nwrap (t) = θ n1wrap (t)-θ n2wrap (t); for θ nwrap (t) is unwrapped to obtain θ n (t), and then multiply it by the coefficient λ2 / (λ2-λ1) to obtain the true phase corresponding to the wavelength λ1, thereby obtaining the final true phase information, as follows:
[0053] The host computer feedback software receives the data to control the acquisition module to extract the 2n groups of three-step phase-shift interference light intensity signals I 1,n1 (t), I 1,n2 (t), I 1,n3 (t), I 2,n1 (t), I 2,n2 (t), I 2,n3 (t); Using the inverse tangent method, the corresponding 2n groups of wrapped phases are obtained as follows:
[0054]
[0055] The difference between the phase signals corresponding to the two wavelengths can be obtained as the wrapping phase θ of the equivalent wavelength. nwrap (t):
[0056] θ nwrap (t) = θ n1wrap (t)-θ n2wrap (t) (20)
[0057] The phase θ of the equivalent synthetic wavelength nwrap (t) is unwrapped to obtain the phase θ n (t), we can further obtain the true phase information corresponding to the wavelength λ1:
[0058] θ n1 (t) = θ n (t)·λ2 / λ2-λ1 (21)
[0059] Combine Figure 1A time-division multiplexing (TDDM) high-signal-to-noise ratio (SNR) pipeline anti-destruction real-time monitoring method is described. The device comprises a first laser 1, a second laser 2, a first wavelength division multiplexer 3, an acousto-optic modulator 4, a phase modulator 5, a circulator 6, a telemetry fiber 7, a 1xN coupler 8, a Michelson interferometer array 9, a pipeline 11, a delayed transmission fiber 10, a second wavelength division multiplexer 12, a photodetector 13, a data control and acquisition module 14, a voltage amplifier module 16, and host computer feedback software 15. The first laser 1 and the second laser 2 are each connected to the first wavelength division multiplexer 3 via optical fibers. The first wavelength division multiplexer 3, the acousto-optic modulator 4, the phase modulator 5, and port 6-1 of the circulator 6 are sequentially connected via optical fibers. Port 6-2 of the circulator 6 is connected to the telemetry fiber 7 via optical fibers. The telemetry fiber 7 is also connected to the 1xN coupler 8, the delayed transmission fiber 10, the Michelson interferometer array 9, and the pipeline 11 via optical fibers. The port 6-3 of the circulator 6, the second wavelength division multiplexer 12 and the photodetector 13 are connected via optical fibers. The data control acquisition module 14 is connected to the photodetector 13, the voltage amplification module 16, the phase modulator 5 and the host computer feedback software 15 respectively.
[0060] The laser light emitted by the first laser 1 and the second laser 2 sequentially passes through the first wavelength division multiplexer 3, the acousto-optic modulator 4, and the phase modulator 5. The data processing module 14 generates pulse-modulated and phase-modulated signals, providing the pulse-modulated signal to the acousto-optic modulator 4 through the voltage amplifier module 16, while simultaneously providing phase modulation to the phase modulator 5, thereby forming a phase-modulated pulse train. The phase-modulated pulse train passes through the circulator 6 and enters the telemetry fiber 7. Then, through the 1xN coupler 8 and the delay fiber 10, it enters the time-division multiplexed Michelson interferometer array 9, which is evenly spaced and applied to the pipeline surface 11. The time-division multiplexed Michelson interferometer array 9 constitutes a highly sensitive vibration sensor. The optical signal returning from the pipeline surface 11 passes through the Michelson interferometer array 9, the delay fiber 10, the 1xN coupler 8, the telemetry fiber 7, and enters the circulator 6. Finally, it passes through the second wavelength division multiplexer 12 and enters the corresponding photodetector 13 for photoelectric conversion. The data control and acquisition module 14 collects and processes the electrical signal, then transmits it to the host computer software 15. The host computer software 15 demodulates each set of three-step phase-shifted signals to obtain each set of wrapped phase signals. It also constructs an equivalent synthetic wavelength using the wavelengths of the first laser 1 and the second laser 2 to obtain the final unwrapped phase. This enables real-time anti-tampering monitoring of pipelines with a high signal-to-noise ratio.
Claims
1. A time-division multiplexing high signal-to-noise ratio pipeline anti-destruction real-time monitoring method, characterized in that: The steps include: Step 1: Turn on the first laser and the second laser. The lasers emitted by the first laser and the second laser are coupled through a first wavelength division multiplexer to form a dual-wavelength laser, i.e., the wavelength of the first laser and the wavelength of the second laser. The dual-wavelength laser then passes through an acousto-optic modulator, a phase modulator, and a circulator into the telemetry optical fiber. The data control and acquisition module drives the acousto-optic modulator through the voltage amplification module and simultaneously generates a phase modulation signal to act on the phase modulator. Step 2: The phase-modulated dual-wavelength laser beam is split into N paths by a coupler through the telemetry fiber and then enters the time-division multiplexing Michelson interferometer array through the delay fiber. The interference signal reflected back by each sensor unit on the pipeline surface passes through the coupler. The optical signal carrying the sensor information from the telemetry fiber returns to the circulator and enters the second wavelength division multiplexer for separation by wavelength, and then enters the corresponding photodetector. The data control and acquisition module receives the electrical signals converted by the photoelectric detectors, extracts the light intensity signal and transmits the phase-shift interference signal to the host computer feedback software; Step 3: The electrical signal of step 2 is subjected to the delay of the calibration interference light intensity signal and the modulated pulse signal to obtain a three-step phase shift signal; Step 4: Based on the three-step phase-shifted signal, the inverse tangent method is used to obtain the wrapped phases corresponding to the wavelength of the first laser and the wavelength of the second laser respectively. After unwrapping the wrapped phases, the real phase corresponding to the wavelength of the first laser is obtained, thereby obtaining the final real phase information.
2. A time-division multiplexing high signal-to-noise ratio pipeline anti-destruction real-time monitoring method according to claim 1, characterized in that: In step 1, the wavelength λ1 of the first laser is smaller than the wavelength λ2 of the second laser, and the phase modulator makes the phase modulation amount generated by each pulse in a pulse sequence be [π / 2; -π / 2, 0] respectively.
3. The time-division multiplexing high signal-to-noise ratio pipeline anti-destruction real-time monitoring method according to claim 1 is characterized in that: In step 2, the light intensity signal is extracted as follows: The interference light intensity of the nth sensing channel corresponding to different wavelengths at a certain vibration point on the telemetry optical fiber extracted by the data control acquisition module can be expressed as: Where A and B are proportional to the input light intensity, and B = κA, κ ≤ 1 is the visibility of the interference fringes; is the final phase modulation term, satisfying is the phase modulation amount produced by the phase modulator, and τ is the delay produced by the laser passing through the two arms of the interferometer; Specifically, it can be expressed as: Where k is an integer and T is the period of the modulation signal; From formula (2), we can get Substituting into formula (1) we can get:
4. A time-division multiplexing high signal-to-noise ratio pipeline anti-destruction real-time monitoring method according to claim 3, characterized in that: Step 3 is as follows: the data control acquisition module collects the corresponding electrical signal, and obtains 2n groups of corresponding three-step phase-shift signals by calibrating the delay between the interference light intensity signal and the modulated pulse signal. Specifically, it can be expressed as:
5. A time-division multiplexing high signal-to-noise ratio pipeline anti-destruction real-time monitoring method according to claim 4, characterized in that: Step 4 is as follows: the host computer feedback software receives the 2n groups of three-step phase shift signals extracted by the data control acquisition module, and the host computer feedback software uses the inverse tangent method to obtain the package phase θ corresponding to the wavelength λ1 of the first laser and the wavelength λ2 of the second laser. n1wrap (t) and θ n2wrap (t), and the difference between the two is obtained, that is, the wrapping phase θ corresponding to the synthetic wavelength nwrap (t) = θ n1wrap (t)-θ n2wrap (t); for θ nwrap (t) is unwrapped to obtain θ n (t), and then multiply it by the coefficient λ2 / (λ2-λ1) to obtain the true phase corresponding to the wavelength λ1, thereby obtaining the final true phase information.
6. A time-division multiplexing high signal-to-noise ratio pipeline anti-destruction real-time monitoring method according to claim 5, characterized in that: The 2n groups of three-step phase shift signals are I 1,n1 (t), I 1,n2 (t), I 1,n3 (t), I 2,n1 (t), I 2,n2 (t), I 2,n3 (t); The inverse tangent method obtains the corresponding 2n groups of wrapped phases as follows: The difference between the phase signals corresponding to the two wavelengths is obtained to obtain the wrapping phase θ of the equivalent wavelength. nwrap (t): i nwrap (t)=θ n1wrap (t)-θ n2wrap (t) (6) The phase θ of the equivalent synthetic wavelength nwrap (t) is unwrapped to obtain the phase θ n (t), and obtain the true phase information corresponding to wavelength λ1: i n1 (t)=θ n (t)·λ2 / λ2-λ1 (7).
7. A time-division multiplexing high signal-to-noise ratio pipeline anti-destruction real-time monitoring device, characterized in that: The invention comprises a first laser (1), a second laser (2), a first wavelength division multiplexer (3), an acousto-optic modulator (4), a phase modulator (5), a circulator (6), a telemetry optical fiber (7), a 1xN coupler (8), a Michelson interferometer array (9), a pipeline (11), a delayed transmission optical fiber (10), a second wavelength division multiplexer (12), a photodetector (13), a data control acquisition module (14), a voltage amplification module (16) and a host computer feedback software (15); wherein the first laser (1) and the second laser (2) are respectively connected to the first wavelength division multiplexer (3) through optical fibers; the first wavelength division multiplexer (3), the acousto-optic modulator (4 ), the phase modulator (5) and the port (6-1) of the circulator (6) are sequentially connected through optical fibers; the port (6-2) of the circulator (6) is connected to the telemetry optical fiber (7) through optical fibers; the telemetry optical fiber (7) is connected to the 1xN coupler (8), the delayed transmission optical fiber (10), the Michelson interferometer array (9), and the pipeline (11) through optical fibers; the port (6-3) of the circulator (6), the second wavelength division multiplexer (12) and the photodetector (13) are connected through optical fibers; the data control acquisition module (14) is respectively connected to the photodetector (13), the voltage amplification module (16), the phase modulator (5), and the host computer feedback software (15); The lasers emitted by the first laser (1) and the second laser (2) pass through the first wavelength division multiplexer (3), the acousto-optic modulator (4), and the phase modulator (5) in sequence; the data processing module (14) generates a pulse modulation signal and a phase modulation signal, provides the pulse modulation signal to the acousto-optic modulator (4) through the voltage amplification module (16), and simultaneously provides phase modulation to the phase modulator (5), thereby forming a phase-modulated pulse sequence; The phase-modulated pulse sequence laser passes through a circulator (6) and enters a telemetry optical fiber (7), and then passes through a 1xN coupler (8) and a time-delay optical fiber (10) to enter a time-division multiplexing Michelson interferometer array (9) equally spaced and attached to a pipe surface (11); the Michelson interferometer array (9) constitutes a high-sensitivity vibration sensor; the optical signal returned from the pipe surface (11) passes through the Michelson interferometer array (9), the time-delay optical fiber (10), the 1xN coupler (8), and the telemetry optical fiber (7) and enters the circulator (6), and then passes through a second wavelength division multiplexer (12) and enters a corresponding photodetector (13) to realize photoelectric conversion; a data control acquisition module (14) collects the electrical signal and transmits it to a host computer software (15) after processing; the host computer software (15) demodulates each group of three-step phase shift signals to obtain each group of wrapped phase signals, and simultaneously uses the wavelengths of the first laser (1) and the second laser (2) to construct an equivalent synthetic wavelength to obtain a final unwrapped phase.
8. The time-division multiplexing high signal-to-noise ratio pipeline anti-destruction real-time monitoring device according to claim 7 is characterized in that: The first laser (1) and the second laser (2) are coupled via a first wavelength division multiplexer (3), and the interference light intensity signals corresponding to the wavelength λ1 and the wavelength λ2 are separated via a second wavelength division multiplexer (12).
9. The time-division multiplexing high signal-to-noise ratio pipeline anti-destruction real-time monitoring device according to claim 7, characterized in that: The Michelson interferometer array (9) constitutes a high-sensitivity vibration sensor and is applied to the pipeline surface (11) at equal intervals; the telemetry optical fiber (7) and the delay optical fiber (10) are located on the ground surface.
10. The time-division multiplexing high signal-to-noise ratio pipeline anti-destruction real-time monitoring device according to claim 7, characterized in that: The data control acquisition module (14) generates a modulation signal, provides a pulse modulation signal to the acousto-optic modulator (4) through the voltage amplification module (16), and simultaneously provides phase modulation to the phase modulator (5).