WO2020098277A1 - Distributed optical fiber sensing system and control method and control device therefor, and storage medium - Google Patents

Abstract

Disclosed are a distributed optical fiber sensing system and control method and control device therefore, and a storage medium. The distributed optical fiber sensing system comprises: an optical generation module, an optical circulator, a filtering module, an optical detection module, and a data acquisition processing and system control module. The data acquisition processing and system control module determines the state of a sensing optical fiber, controls the distributed optical fiber sensing system to work in a working mode corresponding to the state of the sensing optical fiber, and determines target information according to an input electrical signal and the current working mode.

Description

Distributed optical fiber sensing system and its control method, control device and storage medium

This application requires the priority of a Chinese patent application filed with the Chinese Patent Office on November 14, 2018, with application number 201811353948.X. The entire content of this application is incorporated by reference in this application.

Technical field

Embodiments of the present invention relate to, but are not limited to, a distributed optical fiber sensing system and its control method, control device, and computer-readable storage medium.

Background technique

In the Internet of Everything today, fiber optic sensors have become an important device in the field of structural health monitoring. Compared with traditional electrical sensors, optical fiber-based sensors have a series of advantages such as high integration, easy networking and reuse, intrinsic safety, easy bending, and wide measurement parameters. Brillouin Optical Time Domain Analyzer (BOTDA) as the mainstream distributed optical fiber strain monitoring technology has the advantages of ultra-long sensing distance, high spatial resolution and high measurement accuracy, and is widely used in long distance Safety and health monitoring of large infrastructure.

The sensor link of the BOTDA sensor system must be a ring-shaped closed structure. The pump pulse light and continuous detection light are injected into the fiber from both ends of the sensor fiber respectively. The pump light and detection light transmitted towards each other will be at various positions of the fiber The stimulated Brillouin effect occurs, and the distributed temperature or strain can be measured by detecting the probe light subjected to the stimulated Brillouin scattering effect. However, when the sensing fiber breaks, BOTDA will not be able to measure temperature or strain normally.

Summary of the invention

At least one embodiment of the present application provides a distributed optical fiber sensing system, a control method thereof, a control device, and a computer-readable storage medium. After the sensing optical fiber breaks, the monitoring work can also be performed.

At least one embodiment of the present application provides a distributed optical fiber sensing system, including: an optical generation module, an optical circulator, a filter module, an optical detection module, a data acquisition processing, and a system control module, wherein the optical circulator includes a presence A first port, a second port, and a third port in a sequential relationship, the light generating module includes a first output port and a second output port, and the second output port of the light generating module is connected to the first port of the optical circulator One port, the third port of the optical circulator is connected to the input port of the filter module, the output port of the filter module is connected to the input port of the light detection module, and the output port of the light detection module is connected to The data acquisition processing and system control module, wherein:

The light generating module is configured to output a swept optical signal through a first output port of the light generating module and a second output port of the light generating module according to the data collection processing and control of the system control module Pulsed optical signal; or, output the pulsed optical signal only through the second output port;

The optical circulator is configured to output the input optical signal from the next port corresponding to the input port of the optical circulator;

The filtering module is configured to filter the input optical signal and output it to the optical detection module;

The optical detection module is configured to convert the input optical signal into an electrical signal and output the electrical signal to the data collection processing and system control module;

The data collection processing and system control module is configured to determine the state of the sensing optical fiber, control the distributed optical fiber sensing system to work in a working mode corresponding to the state of the sensing optical fiber, and, according to the input electrical signal And the current working mode determines the target information.

At least one embodiment of the present application provides a distributed optical fiber sensing system, including: a light generation module, an optical circulator, a first filter module, a second filter module, a light detection module, a data collection processing and system control module, and a second A coupler, a first optical switch module, and a second optical switch module, wherein the optical circulator includes a first port, a second port, and a third port in a sequential relationship, and the light generation module includes a first output port and A second output port, the second coupler includes an output port and two input ports, the first optical switch module includes an input port, a fifth output port and a sixth output port, and the second optical switch module includes an input Port, seventh output port and eighth output port, the first output port of the light generating module is connected to the input port of the first optical switch module, and the sixth output port of the first optical switch module is connected to all An input port of the second coupler, an output port of the second coupler is connected to the input port of the light detection module, and an output port of the light detection module is connected to the data acquisition processing and system control module; The second output port of the light generation module is connected to the first port of the optical circulator, the third port of the optical circulator is connected to the input port of the second optical switch module, and the second optical switch The seventh output port of the module is connected to one end of the first filter module, the other end of the first filter module is connected to the input port of the light detection module, and the eighth output port of the second optical switch module is connected To one end of the second filter module, the other end of the second filter module is connected to another input port of the second coupler, wherein:

The light generating module is configured to output a swept frequency optical signal through the first output port of the light generating module and a pulsed optical signal through the second output port of the light generating module;

The optical circulator is configured to output the input optical signal from the next port corresponding to the input port of the optical circulator;

The first filter module is configured to filter the input optical signal and output it to the light detection module;

The second filtering module is configured to filter the input optical signal and output it to the second coupler;

The first optical switch module is configured to output the input optical signal from the fifth output port of the first optical switch module according to the data collection processing and control of the system control module, or from the first The sixth output port of the optical switch module outputs;

The second optical switch module is configured to output the input optical signal from the seventh output port of the second optical switch module according to the data collection processing and the control of the system control module, or from the second The eighth output port of the optical switch module;

The second coupler is configured to coherently beat the optical signal input from one input port of the second coupler and the optical signal input from another input port of the second coupler to output to all The light detection module;

The optical detection module is configured to convert the input optical signal into an electrical signal and output the electrical signal to the data collection processing and system control module;

The data collection processing and system control module is configured to determine the state of the sensing optical fiber, control the distributed optical fiber sensing system to work in a working mode corresponding to the state of the sensing optical fiber, and, according to the input electrical signal And the current working mode determines the target information.

At least one embodiment of the present application provides a control method of a distributed optical fiber sensing system, including:

The state of the sensing optical fiber is determined, and the distributed optical fiber sensing system is controlled to work in a working mode corresponding to the state of the sensing optical fiber.

At least one embodiment of the present application provides a control device, including a memory and a processor, where the memory stores a program, and when the program is read and executed by the processor, the control method according to any one of the embodiments is implemented .

At least one embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores one or more programs, and the one or more programs may be executed by one or more processors to The control method described in any of the embodiments is implemented.

Other features and advantages of the present application will be explained in the subsequent description, and partly become obvious from the description, or be understood by implementing the present application. The objects and other advantages of the present application can be realized and obtained by the structures particularly pointed out in the description, claims and drawings.

Brief description of the drawings

The drawings are used to provide a further understanding of the technical solutions of the present application, and form a part of the specification. They are used to explain the technical solutions of the present application together with the embodiments of the present application, and do not constitute limitations on the technical solutions of the present application.

1 is a block diagram of a distributed optical fiber sensing system provided by an embodiment of this application;

2a to 2d are schematic diagrams of different implementations of the light generating module in the system shown in FIG. 1;

3a to 3c are block diagrams of a distributed optical fiber sensing system provided by an embodiment of the present invention;

4 is a flow chart of a control method provided by an embodiment of this application;

Figure 5 is a schematic diagram of the BOTDR mode of the system shown in Figure 2a;

6 is a flowchart of the system control method shown in FIG. 2a;

7 is a block diagram of a distributed optical fiber sensing system provided by another embodiment of this application;

8 is a schematic diagram of an embodiment of a light generating module in the system shown in FIG. 1;

9a to 9c are schematic diagrams of adding an amplification device to the system shown in FIG. 1;

10 is a block diagram of a distributed optical fiber sensing system provided by an embodiment of this application;

11a is a schematic diagram of the distributed optical fiber sensing system shown in FIG. 10 in the BOTDA mode;

11b is a schematic diagram of the distributed optical fiber sensing system shown in FIG. 10 in the BOTDR mode;

FIG. 12 is a flowchart of the system control method shown in FIG. 10;

13 is a block diagram of a control device provided by an embodiment of this application;

14 is a block diagram of a computer-readable storage medium provided by an embodiment of the present application.

detailed description

To make the objectives, technical solutions, and advantages of the present application clearer, the embodiments of the present application will be described in detail below with reference to the drawings. It should be noted that the embodiments in the present application and the features in the embodiments can be arbitrarily combined with each other without conflict.

The steps shown in the flowcharts of the figures can be performed in a computer system such as a set of computer-executable instructions. And, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be performed in an order different from here.

An embodiment of the present application provides a distributed optical fiber sensing system that combines BOTDA and Brillouin Optical Time-Domain Reflectometry (BOTDR) to continue working when the sensing fiber breaks.

As shown in FIG. 1, a distributed optical fiber sensing system provided by an embodiment of the present application includes: a light generation module 1, an optical circulator 2, a filtering module 3, a light detection module 4, a data acquisition processing and system control module 5, wherein , The optical circulator 2 includes a first port A1, a second port A2, and a third port A3 in a sequential relationship, and the light generating module 1 includes a first output port A4 and a second output port A5, the light generating The second output port A5 of the module 1 is connected to the first port A1 of the optical circulator 2, the third port A3 of the optical circulator 2 is connected to the input port A6 of the filtering module 3, and the filtering module 3 The output port A7 is connected to the input port A8 of the light detection module 4, the output port A9 of the light detection module 4 is connected to the port A10 of the data acquisition processing and system control module 5, and the sensing fiber F can be connected at Between the first output port A4 of the light generating module 1 and the second port A2 of the optical circulator 2, the sensing fiber F is, for example, a long-distance sensing fiber, where:

The light generating module 1 is configured to output a swept frequency optical signal through the first output port A4 and a pulsed optical signal through the second output port A5 according to the data collection processing and control of the system control module 5; Or, output the pulse optical signal only through the second output port A5;

The optical circulator 2 is configured to output the input optical signal from the next port corresponding to the input port; for example, the optical signal input from the port A1 is output from the port A2, and the optical signal input from the port A2 is from the port A3 Output; optical circulator is a multi-port non-reciprocal optical device. Its typical structure has N ordered ports. When light enters from one port, it outputs from the corresponding next port, and the remaining ports have no output. Among them, there is Two types of optical circulators, one is that the optical signal entering from the last port can be output from the first port, and the other is that the optical signal entering from the last port cannot be output from the first port. In this embodiment, from The optical signal input to port A3 does not limit whether it can be output from port A1. In addition, FIG. 1 only shows an optical circulator including three ports. The present application is not limited to this, and an optical circulator with more ports may be used.

The filtering module 3 is configured to filter the input optical signal and output it to the optical detection module;

The light detection module 4 is configured to convert the input optical signal into an electrical signal, and output the electrical signal to the data collection processing and system control module 5;

The data acquisition processing and system control module 5 is configured to determine the state of the sensing optical fiber, control the distributed optical fiber sensing system to work in a working mode corresponding to the state of the sensing optical fiber, and, according to the input power The signal and the current working mode determine the target information. Among them, the target information is information that the optical fiber sensing system needs to detect, such as strain information, temperature information, and so on.

Compared with the BOTDA in the related art, the monitoring work cannot be continued after the optical fiber is broken. The solution provided in this embodiment changes the working mode of the system according to the state of the sensing fiber, and changes the working mode of the system to corresponding when the sensing fiber is broken The working mode of the system enables the system to continue monitoring in the case of fiber breakage (monitoring from the signal light incident position to the breakpoint position area). The solution provided by this embodiment has a simple device structure, does not require additional introduction of other modules, is easy to implement, and has low cost.

The state of the sensing optical fiber includes a fiber-broken state and a non-fiber-broken state. In one embodiment, the data collection processing and system control module 5 controls the distributed fiber sensing system to work in a state with the sensor fiber The corresponding working modes include:

When the sensing optical fiber is not broken, the distributed optical fiber sensing system is controlled to operate in the first mode (BOTDA mode), and the light generating module 1 is controlled to output a swept optical signal and a pulsed optical signal; in this mode, the optical The generating module 1 generates two optical signals. One swept optical signal (probe light) is injected into the tail end of the sensing fiber, and one pulse optical signal (pump light) passes through the optical circulator 2 and then injected into the front end of the sensor fiber. Finally, the probe light The signal enters the filter module through the optical circulator 2 and is converted into an electrical signal by the optical detection module 4 and then collected and analyzed by the data collection processing and system control module 5 to obtain the monitoring result.

When the sensing optical fiber is broken, the distributed optical fiber sensing system is controlled to work in the second mode (BOTDR mode), and the light generating module 1 is controlled to output only pulsed optical signals. In this mode, the light generation module 1 generates an optical signal, and a pulsed optical signal (as detection light) passes through the optical circulator 2 and is injected into the front end of the sensing fiber. The backscattered light enters the filter module 3 through the optical circulator 2 and passes through After the light detection module 4 is converted into an electrical signal, the data collection and processing and the system control module 5 perform collection and analysis to obtain monitoring results.

It should be noted that when the sensing optical fiber is not broken, the distributed optical fiber sensing system can also be controlled to work in the second mode (BOTDR mode).

The signals collected in the two modes are different, and the corresponding processing and analysis methods are also different. Therefore, the processing method needs to be changed at the data collection processing and system control module 5 (corresponding to the working mode). In addition, the device parameters also need to be changed according to different working modes. For example, the parameters of related devices (such as lasers) and filter modules in the light generation module are changed accordingly.

In an embodiment, the data collection processing and system control module 5 is further configured to determine whether to cut the fiber according to the change of the electrical signal. For example, if the difference between the electrical signal at the current moment and the electrical signal collected at the previous moment is greater than or greater than or equal to the preset value, fiber breakage occurs. The electrical signal is, for example, a voltage amplitude value. The solution provided by this embodiment can realize automatic detection of fiber breakage. Of course, the electrical signal values at multiple times can also be taken to determine whether the fiber is broken, and so on. It should be noted that it is also possible to receive an external command to learn that a fiber break has occurred, and so on.

In an embodiment, the data collection processing and system control module 5 is further configured to determine the fiber breakage position of the sensing fiber according to the change of the electrical signal. The solution provided in this embodiment can determine the break point of the sensing fiber, that is, the fiber break position. The difference between the electrical signal strength when the optical fiber is normally connected and the electrical signal strength when the optical fiber is broken can be used to determine the location of the abnormal optical fiber connection.

In an embodiment, the data acquisition processing and system control module is further configured to adjust device parameters of the distributed optical fiber sensing system according to the fiber breakage position. The device parameters corresponding to different fiber breakage positions can be determined through testing in advance, a correspondence table between the fiber breakage positions and the device parameters can be established, and then the corresponding relationship table can be searched according to the fiber breakage positions to determine the device parameters. The device parameters include, but are not limited to: the pulse encoding mode of the optical signal pulse modulation module, the working mode of the photodetector, and the amplification parameters of the distributed optical amplification module.

In an embodiment, as shown in FIG. 2a, the light generating module 1 includes a laser 101, a first coupler 102, an optical signal sweep module 103, and an optical signal pulse modulation module 104, and the first coupler 102 includes an input Port A11 and two output ports A12 and A13, the laser 101 is connected to the input port A11 of the first coupler 102, and an output port A12 of the first coupler 102 is connected to the optical signal frequency sweep module 103, another output port A13 of the first coupler 102 is connected to the optical signal pulse modulation module 104, and the output port of the optical signal frequency sweep module 103 is the first output port A4 of the optical generation module The output port of the optical signal pulse modulation module 104 is the second output port A5 of the light generation module, where:

The laser 101 is configured to generate an optical signal to the first coupler 102;

The first coupler 102 is configured to divide the input optical signal into two channels, one channel output to the optical signal frequency sweep module 103, and one channel output to the optical signal pulse modulation module 104;

The optical signal frequency sweeping module 103 is configured to modulate the input optical signal into a frequency sweeping optical signal and output it through the first output port A4; for example, performing frequency shifting.

The optical signal pulse modulation module 104 is configured to convert the input optical signal into a pulsed optical signal and output it through the second output port A5.

The laser 101 generates an optical signal, which is input to the first coupler 102, and the first coupler 102 divides the input optical signal into two channels, which are input to the optical signal frequency sweep module 103 and the optical signal pulse modulation module 104, respectively. The frequency module 103 performs frequency shift on the input optical signal and outputs it; the optical signal pulse modulation module 104 modulates the input optical signal into a pulsed optical signal and outputs it.

In another embodiment, as shown in FIG. 2b, the light generating module 1 includes a laser 105, a laser 106, and an optical signal pulse modulation module 104, and the laser 106 is connected to the optical signal pulse modulation module 104, wherein the laser 105 is scannable. Frequency continuous laser source, the laser 106 is a continuous laser source, the output port of the laser 105 is the output port A4 of the light generating module 1, and the output port of the optical signal pulse modulation module 104 is the first port of the light generating module 1. Two output ports A5, wherein the laser 105 outputs a swept frequency optical signal; the laser 106 outputs an optical signal to the optical signal pulse modulation module 104, and the optical signal pulse modulation module 104 modulates the input optical signal into a pulsed optical signal and outputs it.

In another embodiment, as shown in FIG. 2c, the light generating module 1 includes a laser 107, a laser 108, and an optical signal frequency sweep module 103, and the laser 107 is connected to the optical signal frequency sweep module 103, and the optical signal frequency sweep module The output port of 103 is the output port A4 of the light generation module, and the output port of the laser 108 is the output port A5 of the light generation module, where the laser 107 is a continuous laser source, the laser 108 is a pulsed laser source, and the laser 108 outputs Pulsed optical signal; the laser 107 outputs the optical signal to the optical signal frequency sweep module 103, and the optical signal frequency sweep module 103 performs frequency shift on the input optical signal and outputs it.

In another embodiment, as shown in FIG. 2d, the light generating module 1 includes a laser 105 and a laser 108, the output port of the laser 105 is the output port A4 of the light generating module 1, and the output port of the laser 108 is the light The output port A5 of the generating module 1, the laser 105 is a sweepable continuous laser source, the laser 108 is a pulsed laser source, the laser 105 is set to output a swept optical signal through port A4, and the laser 108 is set to output a pulsed optical signal through port A5 .

The data acquisition and processing and system control module 5 can control the optical signal sweep module 103, including not limited to the size and rate of frequency shift, and the adjustment of the optical power of continuous optical signals; to control the optical signal pulse modulation module 104, Including not limited to the width and period of the electric pulse, the adjustment of the optical power of the pulsed optical signal; processing and analysis of the received optical signal.

In an embodiment, the distributed optical fiber sensing system further includes an amplification device, as shown in FIG. 3a, the amplification device includes a first wavelength division multiplexer 6, a distributed optical amplification module 7, and a second wavelength division Multiplexer 8, the first wavelength division multiplexer 6 includes a first input port A14 and a second input port A15, and an output port A16; the second wavelength division multiplexer 8 includes a third input port A19 and a fourth input port A20, and an output port A21, the distributed optical amplification module 7 includes a third output port A17 and a fourth output port A18, the first output port A4 of the light generating module 1 is connected to The first input port A14 of the first wavelength division multiplexer 6 and the third output port A17 of the distributed optical amplification module 7 are connected to the second input port A15 of the first wavelength division multiplexer. The fourth output port A18 of the distributed optical amplifier module 7 is connected to the fourth input port A20 of the second wavelength division multiplexer 8, and the second port A2 of the optical circulator 2 is connected to the second wave The third input port A19 of the division multiplexer 8; the first wavelength division multiplexer 6 and the second wavelength division multiplexer 8 are passive devices for coupling optical signals of different wavelengths or separating optical signals of different wavelengths. The distributed optical amplification module 7 is, for example, a Raman optical amplifier, which implements distributed amplification based on stimulated Raman scattering (Simulated Raman Scattering, SRS). The sensing fiber F is connected between the port A21 and the port A16.

The first wavelength division multiplexer 6 and the second wavelength division multiplexer 8 are typically 2 * 1 structures, that is, one com port output port and two input ports. If a high-order distributed Raman amplification scheme is adopted, it is N * 1 structure, and N is a natural number.

In the solution of this embodiment, a distributed amplification module is introduced, so that the output power of the distributed amplification module is intelligently adjusted according to different monitoring distances, and the performance of BOTDR / BOTDA in each sensing distance is further improved.

In an embodiment, the distributed optical fiber sensing system further includes an amplification device, as shown in FIG. 3b, the amplification device includes a first wavelength division multiplexer 6 and a distributed optical amplification module 7, the first The wavelength division multiplexer 6 includes a first input port A14 and a second input port A15, and an output port A16; the first output port A4 of the light generation module is connected to the first wavelength division multiplexer 6 The first input port A14, the output port A17 of the distributed optical amplifier module is connected to the second input port A15 of the first wavelength division multiplexer; the sensing fiber is connected between port A2 and port A16.

In an embodiment, the distributed optical fiber sensing system further includes an amplification device, as shown in FIG. 3c, the amplification device includes a distributed optical amplification module 7 and a second wavelength division multiplexer 8, the second The wavelength division multiplexer 8 includes a third input port A19 and a fourth input port A20, and an output port A21, and the output port A18 of the distributed optical amplifier module 7 is connected to the second wavelength division multiplexer 7 The fourth input port A20, the second port A2 of the optical circulator is connected to the third input port A19 of the second wavelength division multiplexer. The sensing fiber is connected between port A4 and port A21.

Wherein, the data collection processing and system control module 5 can control the distributed optical amplification module 7, including but not limited to the adjustment of the power level of the pump optical signal in distributed amplification.

It should be noted that the light generating module 1 of FIGS. 3a to 3c may be any one between FIGS. 2a to 2d, and details are not described here.

As shown in FIG. 4, an embodiment of the present application provides a method for controlling a distributed optical fiber sensing system, including: step 401 and step 402.

In step 401, the state of the sensing fiber is determined.

In step 402, the distributed optical fiber sensing system is controlled to operate in an operating mode corresponding to the state of the sensing optical fiber.

In an embodiment, determining the state of the sensing optical fiber in step 401 includes: judging whether the sensing optical fiber is broken according to changes in the electrical signals collected by the data collection process and the system control module.

In an embodiment, the determining whether the sensing optical fiber is broken according to the change of the collected electrical signal includes:

When the change of the collected electrical signal is greater than or greater than or equal to a preset value, it is determined that there is fiber breakage. The change of the electric signal is, for example, the change of the voltage amplitude of the electric signal at the current time and the electric signal at the previous time.

In an embodiment, the operation mode corresponding to the state of the sensing optical fiber for controlling the distributed optical fiber sensing system includes:

When the sensing optical fiber is not broken, the distributed optical fiber sensing system is controlled to work in the first mode, and the light generating module is controlled to output a swept optical signal and a pulsed optical signal;

When the sensing optical fiber is broken, the distributed optical fiber sensing system is controlled to work in the second mode, and the light generating module is controlled to output only pulsed optical signals.

In an embodiment, the method further includes: determining a fiber break position according to the change of the collected electrical signal.

In an embodiment, after determining the position of the fiber break according to the change of the electrical signal, the method further includes: adjusting device parameters of the distributed optical fiber sensing system according to the position of the fiber break.

The working process of distributed optical fiber sensing is further described below with the system shown in FIG. 2a.

The BOTDR in Figure 2a is a relatively simple direct detection BOTDR system. The optical signal frequency sweep module 103 and the optical signal pulse modulation module 104 are controlled by the data acquisition processing and system control module 5.

The default operating mode of the distributed optical fiber sensing system is the first mode (BOTDA mode). At this time, the data acquisition processing and system control module 5 controls the optical signal sweep module 104 to work normally, and the center wavelength of the filter module 3 and the laser 101 The output wavelength of the sensor is the same, the signal light received by the light detection module 4 is the continuous detection light injected into the tail end of the sensing fiber F; when a fiber breakage occurs somewhere in the sensor fiber F, the data acquisition processing and system control module 5 controls the light signal The frequency sweep module 103 is closed, as shown in FIG. 5, at this time, the signal light received by the photodetector module 4 is the self-released Brillouin generated by the self-released Brillouin action in the sensor fiber F by the pulse light injected into the front end of the sensor fiber F Backscattered light from the signal. The specific work process includes:

a) The signal light output by the laser 101 is divided into two channels by the first coupler 102. The two channels of light are used as the detection light (A12 port output) and the pumping light (A13 port output) in the BOTDA mode as the BOTDA mode. The light of the pump light at the same time is used as the detection signal light in the BOTDR mode (second mode);

b) The detection light is modulated by the optical signal sweep module 103, the original carrier is frequency shifted, and then injected into the sensing fiber F (the system works in BOTDA mode at this time), and data collection occurs when the sensing fiber F is broken The processing and system control module 5 turns off the optical signal sweep module 103 (at this time the system works in BOTDR mode);

c) The pump light is modulated into pulse light by the optical signal pulse modulation module 104, and enters the sensing fiber F through the circulator 2;

d) The self-published Brillouin signal light of forward-propagated detection light and back-scattered pump light is output through the port A3 of the circulator, input to the light detection module 4 through the filter module 3, and converted into point signals by the light detection module 4 , And finally received and analyzed by the data collection and processing and system control module 5.

As shown in FIG. 6, the following steps 601 to 610 are included.

In step 601, the system works in BOTDR mode and collects electrical signals.

In step 602, the voltage amplitude of the collected electrical signal is judged. When the voltage amplitude drops suddenly, step 603 is executed; otherwise, step 601 is executed.

During normal operation, the system is in BOTDA mode, and the optical detection module 4 receives continuous detection optical signals. If a fiber breakage occurs at a certain position of the sensing fiber link at a certain time, this will cause the continuous detection optical signals to fail to reach The light detection module 4, at this time, the light detection module 4 receives a very weak backscattered light signal of the pulsed light signal, resulting in a sudden voltage drop.

In step 603, analyze the voltage amplitude at the current moment (the moment of sag) and the previous moment, if it meets the fiber-cutting situation (the change value of the voltage amplitude is greater than or equal to the preset value, and the voltage amplitude at the current moment is not 0) Go to step 603, if it does not meet the fiber cut situation, go to step 610.

Among them, the non-fiber-breaking situation includes the failure of the system equipment, such as a certain module failure, for example, when the current voltage is 0, it is judged as a system failure. Of course, it is not necessary to judge whether the system is faulty here, not according to the voltage amplitude, and judge by other methods, such as directly monitoring the device.

In step 604, the sampled signals at the time of the sag and the time immediately before the sag are compared and analyzed to determine the distance between the broken fiber position and the incident end, and the distributed optical fiber sensing system is turned off.

In step 605, the working mode of the distributed optical fiber sensing system is switched from the BOTDA mode to the BOTDR mode.

The mode switching includes: adjusting the data collection and processing and the signal processing and analysis method of the system control module (adjusted to the analysis and processing method corresponding to the BOTDR mode).

In step 606, the working state of the device is adjusted (the device parameters are adjusted) according to the distance between the fiber break position and the incident end.

For example, the parameters of the laser 101 are adjusted. When there is a distributed optical amplification module, the parameters of the distributed optical amplification module are also adjusted. Adjusting the parameters according to the position of the fiber break can further improve the accuracy of the measurement results.

In step 607, the distributed optical fiber sensing system is restarted according to the new device parameter settings.

In step 608, perform validity analysis on the received signal in the BOTDR mode: if the signal is normal, go to step 609, if the signal is abnormal, go to step 610.

Among them, performing validity analysis refers to determining whether the signal is within the parameter range of the BOTDR mode.

In step 609, report the first information and end; for example, report "the fiber breakage position is at x, xxx km, and the system has switched to the BOTDR mode, and the 0 ~ x, xxx km sensor fiber will continue to be monitored."

In step 610, the system failure is reported and ends.

It should be noted that, in the above embodiment, only switching from BOTDA to BOTDR is described, and switching from BOTDR to BOTDA may also be performed. Similar to the above process, but the changes of the signals collected at this time are different. When the signal changes are consistent with the situation where the fiber is not broken, the corresponding can be switched to BOTDA mode.

In this embodiment, the default operating mode of the distributed optical fiber sensing system is the BOTDA state. When a fiber breakage is detected at any position of the sensor fiber, the distance between the fiber breakage position and the fiber entrance position will be automatically reported and recorded, and it will work The mode is switched to the BOTDR mode of single-ended detection, so that some fiber links can still be monitored normally. In addition, the power of the laser and distributed optical amplification module is adjusted according to the recorded distance to ensure that relatively good measurement results are achieved at different monitoring distances. The above solution combines the long-distance high-performance characteristics of BOTDA and the simplicity of single-end measurement of BOTDR, which improves the adaptability and engineering practicability of the distributed optical fiber sensing system, while having a relatively low overall system cost.

The combination of BOTDA and coherent detection type BOTDR makes the performance of the BOTDR system further improved. As shown in FIG. 7, another embodiment of the present application provides a distributed optical fiber sensing system, including: an optical generation module 1, an optical circulator 2, a data acquisition processing and system control module 5, a first optical switch module 9, A second optical switch module 10, a second coupler 11, a first filter module 12, a second filter module 13, and a light detection module 14, wherein the optical circulator 2 includes a first port A1 and a second port in a sequential relationship A2 and a third port A3, the light generating module 1 includes a first output port A4 and a second output port A5, the second coupler 11 includes two input ports A22, A23 and an output port A24, the first The optical switch module 9 includes an input port A25, a fifth output port A26, and a sixth output port A27. The second optical switch module 10 includes an input port A28, a seventh output port A29, and an eighth output port A30. The first output port A4 of the module 1 is connected to the input port A25 of the first optical switch module 9, and the sixth output port A27 of the first optical switch module 9 is connected to an input port of the second coupler 11 A22, the output port A24 of the second coupler is connected to the input port A31 of the light detection module 14, and the output port of the light detection module 14 is connected to the port A10 of the data acquisition processing and system control module 5; The second output port A5 of the light generating module 1 is connected to the first port A1 of the optical circulator 2, and the third port A3 of the optical circulator 2 is connected to the input port of the second optical switch module 10 A28, the seventh output port A29 of the second optical switch module 10 is connected to one end of the first filter module 12, that is, port A33, and the other end A34 of the first filter module is connected to the light detection module 14 Input port A32, the eighth output port A30 of the second optical switch module 10 is connected to one end A35 of the second filter module 13, and the other end A36 of the second filter module is connected to the second coupler 11 Another input port A23, where:

The light generating module 1 is configured to output a swept optical signal through the first output port A4 and a pulsed optical signal through the second output port A5;

The optical circulator 2 is configured to output the input optical signal from the next port corresponding to the input port;

The first filtering module 12 is configured to filter the input optical signal and output it to the optical detection module 14; in one embodiment, implement BOTDA detection signal light, BOTDR detection signal light, and distributed optical amplification pump Separation of residual light, etc., while ensuring that the optical signal-to-noise ratio of the BOTDA detection signal light is sufficiently large;

The second filter module 13 is configured to filter the input optical signal and output it to the second coupler 11; in one embodiment, implement BOTDR detection signal light, BOTDA detection signal light, and distributed optical amplification pump Separation of residual light, etc., while ensuring that the optical signal-to-noise ratio of the BOTDR detection signal light is sufficiently large;

The first optical switch module 9 is configured to output the input optical signal from the fifth output port A26 of the first optical switch module 9 according to the data collection processing and the control of the system control module 5, or, from The sixth output port A27 of the first optical switch module 9 outputs; wherein, in the BOTDA working mode, the output port A26 functions, at this time the first optical switch module 9 is connected to the input of the first wavelength division multiplexer 11 Port A14, the BOTDA detection signal light enters the sensing fiber 20; in the BOTDR working mode, the output port A27 functions, at this time the first optical switch module 9 is connected to the second coupler 11, the BOTDR intrinsic light enters the second coupler 11.

The second optical switch module 10 is configured to output the input optical signal from the seventh output port A29 of the second optical switch module 10 according to the data collection processing and the control of the system control module 5, or, from The eighth output port A30 of the second optical switch module 10 outputs; wherein, in the BOTDA working mode, the output port A29 of the second optical switch module 10 functions, and at this time the second optical switch module 10 is connected to the first filter Module 12, the BOTDA detection signal light enters the light detection module 14 through the second optical switch module 10 and the first filter module 12; in the BOTDR working mode, the output port A30 of the second optical switch module 10 functions, and the second light The switch module 10 is connected to the second filter module 13 and then to the second coupler 11. The BOTDR detection optical signal enters the second coupler 11 through the second optical switch module 13 and the second filter module 13 and then communicates with the BOTDR intrinsic light The signal is subjected to coherent beat frequency, and finally enters the light detection module 33.

The second coupler 11 is configured to output the optical signal input from one input port of the second coupler 11 and the optical signal input from the other input port of the second coupler after coherent beat frequency To the light detection module 14; the second coupler is typically a 3dB coupler.

The light detection module 14 is configured to convert the input optical signal into an electrical signal, and output the electrical signal to the data collection processing and system control module 5;

The data acquisition processing and system control module 5 is configured to determine the state of the sensing optical fiber, control the distributed optical fiber sensing system to work in a working mode corresponding to the state of the sensing optical fiber, and, according to the input power The signal and the current working mode determine the target information. Among them, the target information is information that the optical fiber sensing system needs to detect, such as strain information, temperature information, and so on.

The distributed optical fiber sensing system provided in this embodiment changes the operating mode of the system according to the state of the sensing optical fiber after the optical fiber is broken, and changes the operating mode of the system to the corresponding operating mode when the optical fiber is broken to achieve the optical fiber breakage In this case, the system continues to carry out monitoring work (monitoring from the signal light incident position to the breakpoint position area). The device has a simple structure, is easy to realize, and has low cost.

In an embodiment, the data collection processing and system control module 5 determining the state of the sensing optical fiber includes: determining whether the sensing optical fiber is broken according to the change of the electrical signal. For example, if the difference between the electrical signal at the current moment and the electrical signal collected at the previous moment is greater than or greater than or equal to the preset value, fiber breakage occurs. The electrical signal is, for example, a voltage amplitude value. The solution provided by this embodiment can realize automatic detection of fiber breakage. Of course, the electrical signal values at multiple times can also be taken to determine whether the fiber is broken, and so on. It should be noted that it is also possible to receive an external command to learn that a fiber cut has occurred, and so on.

In an embodiment, the data acquisition processing and system control module 5 controls the distributed optical fiber sensing system to work in a working mode corresponding to the state of the sensing optical fiber including:

When the sensing optical fiber is not broken, the distributed optical fiber sensing system is controlled to operate in a first mode, and the first optical switch module 9 is controlled to remove the input optical signal from the first optical switch module. Five output ports A26 output to control the second optical switch module to output the input optical signal from the seventh output port A29 of the second optical switch 10; in this mode, the detection optical signal arrives through the first optical switch module 9 The first wavelength division multiplexer 6 then enters the sensing fiber F, enters the optical circulator 2 through the second wavelength division multiplexer 8, from the optical circulator 2 to the second optical switch module 10, and then passes through the first filter module 12 arrives at the light detection module 14 and is converted into electrical signals by the light detection module 14 and then collected and processed by the data collection processing and system control module 5.

When the sensing optical fiber is broken, the distributed optical fiber sensing system is controlled to operate in a second mode, and the first optical switch module 9 is controlled to remove the input optical signal from the first optical switch module 9 The sixth output port A27 is output to control the second optical switch module 10 to output the input optical signal from the eighth output port A30 of the second optical switch module 10. In this mode, the intrinsic optical signal reaches the second coupler 11 through the first optical switch module 9, the detection optical signal enters the sensing fiber through the optical circulator 2 and the second wavelength division multiplexer 8, and its backward scattered light passes through The second wavelength division multiplexer 8 enters the optical circulator 2, from the optical circulator 2 to the second optical switch module 10, and then to the second coupler 11 through the second filter module 12, the second coupler 11 on the input The luminous signal and the backscattered light are subjected to coherent beat frequency and then output to the light detection module 14. After being converted into an electrical signal by the light detection module 14, the data collection and processing and the system control module 5 collect and process it.

The signals collected in the two modes are different, and the corresponding processing and analysis methods are also different. Therefore, the processing method needs to be changed at the data collection processing and system control module 5 (corresponding to the working mode). In addition, the device parameters also need to be changed according to different working modes, for example, parameters of related devices (such as lasers) in the light generating module 1 are changed accordingly.

In an embodiment, the data collection processing and system control module 5 is further configured to determine the fiber breakage position of the sensing optical fiber according to the change of the collected electrical signal.

In an embodiment, the data collection processing and system control module 5 is further configured to adjust device parameters of the distributed optical fiber sensing system according to the fiber breakage position. For example, the parameters of the laser in the light generation module 1 are adjusted, and the parameters of the distributed light amplification module 7 are adjusted. The device parameters at different fiber breakage positions can be determined through testing in advance, and a correspondence table between the fiber breakage positions and the device parameters can be established, and then the corresponding relationship table can be searched according to the fiber breakage positions to determine the device parameters.

In an embodiment, as shown in FIG. 8, the light generating module 1 includes a laser 101, a first coupler 102, an optical signal sweep module 103, and an optical signal pulse modulation module 104, and the first coupler 102 includes an input Port A11 and two output ports A12 and A13, the laser 101 is connected to the input port A11 of the first coupler 102, and an output port A12 of the first coupler 102 is connected to the optical signal frequency sweep module 103, another output port A13 of the first coupler 102 is connected to the optical signal pulse modulation module 104, and the output port of the optical signal frequency sweep module 103 is the first output port of the optical generation module 1 A4, the output port of the optical signal pulse modulation module 104 is the second output port A5 of the light generating module 1, wherein,

The laser 101 generates an optical signal, which is input to the first coupler 102, and the first coupler 102 divides the input optical signal into two channels, and inputs them to the optical signal sweep module 103 (as detection light in BOTDA mode or as Eigen light in BOTDR mode) and optical signal pulse modulation module 104 (as pump light in BOTDA mode or detection signal light in BOTDR mode); optical signal sweep module 103 modulates the input optical signal (to the original carrier Frequency shifting) and output; the optical signal pulse modulation module 104 modulates the input optical signal into a pulsed optical signal and outputs it.

The data acquisition and processing and system control module 5 can control the optical signal sweep module 103, including not limited to the size and rate of frequency shift, and the adjustment of the optical power of continuous optical signals; to control the optical signal pulse modulation module 104, Including not limited to the width and period of the electric pulse, the adjustment of the optical power of the pulsed optical signal; processing and analysis of the received optical signal.

It should be noted that the light generating module 1 may also have a structure as shown in FIG. 2b to FIG. 2d, which will not be repeated here.

In an embodiment, the distributed optical fiber sensing system further includes an amplification device, as shown in FIG. 9a, the amplification device includes a first wavelength division multiplexer 6, a distributed optical amplification module 7, and a second wavelength division Multiplexer 8, the first wavelength division multiplexer 6 includes a first input port A14 and a second input port A15, and an output port A16; the second wavelength division multiplexer 8 includes a third input port A19 and a fourth input port A20, and an output port A21, the distributed optical amplifier module 7 includes a third output port A17 and a fourth output port A18, and the output port A26 of the first optical switch module 9 is connected to The first input port A14 of the first wavelength division multiplexer 6 and the third output port A17 of the distributed optical amplification module 7 are connected to the second input port A15 of the first wavelength division multiplexer. The fourth output port A18 of the distributed optical amplifier module 7 is connected to the fourth input port A20 of the second wavelength division multiplexer 8, and the second port A2 of the optical circulator 2 is connected to the second wave The third input port A19 of the division multiplexer 8; the first wavelength division multiplexer 6 and the second wavelength division multiplexer 8 are passive devices for coupling optical signals of different wavelengths or separating optical signals of different wavelengths. The distributed optical amplification module 7 is, for example, a Raman optical amplifier, and implements distributed amplification based on stimulated Raman scattering (SRS). The sensing fiber F is connected between the port A21 and the port A16.

The first wavelength division multiplexer 6 and the second wavelength division multiplexer 8 are typically 2 * 1 structures, that is, one com port output port and two input ports. If a high-order distributed Raman amplification scheme is adopted, it is N * 1 structure, and N is a natural number.

The data collection processing and system control module 5 can control the distributed optical amplification module 7, including but not limited to the adjustment of the power level of the pump optical signal in distributed amplification.

In the solution of this embodiment, a distributed amplification module is introduced, so that the output power of the distributed amplification module is intelligently adjusted according to different monitoring distances, and the performance of BOTDR / BOTDA in each sensing distance is further improved.

In an embodiment, the distributed optical fiber sensing system further includes an amplification device, as shown in FIG. 9b, the amplification device includes a first wavelength division multiplexer 6 and a distributed optical amplification module 7, the first The wavelength division multiplexer 6 includes a first input port A14 and a second input port A15, and an output port A16; the output port A26 of the first optical switch module 9 is connected to the first wavelength division multiplexer 6 The first input port A14, the output port A17 of the distributed optical amplification module is connected to the second input port A15 of the first wavelength division multiplexer; the sensing fiber is connected between port A2 and port A16.

In an embodiment, the distributed optical fiber sensing system further includes an amplification device, as shown in FIG. 9c, the amplification device includes a distributed optical amplification module 7 and a second wavelength division multiplexer 8, the second The wavelength division multiplexer 8 includes a third input port A19 and a fourth input port A20, and an output port A21, and the output port A18 of the distributed optical amplifier module 7 is connected to the second wavelength division multiplexer 7 The fourth input port A20 of the optical circulator 2 is connected to the third input port A19 of the second wavelength division multiplexer. The sensing fiber is connected between port A26 and port A21.

It should be noted that the light generating module 1 of FIGS. 9a to 9c may be any one between FIGS. 2a to 2d, and details are not described here.

The above-mentioned sensing optical fiber F is, for example, a long-distance sensing optical fiber (> 50km). Of course, the present application is not limited thereto.

It should be noted that the control method shown in FIG. 4 can also be applied in the above embodiment. When applied in the above embodiment, the distributed optical fiber sensing system is controlled to work in a state corresponding to the state of the sensing fiber Working modes include:

When the sensing optical fiber is not broken, the distributed optical fiber sensing system is controlled to operate in a first mode, and the first optical switch module 9 is controlled to remove the input optical signal from the first optical switch module 9 The fifth output port A26 is output to control the second optical switch module 10 to output the input optical signal from the seventh output port A29 of the second optical switch;

When the sensing optical fiber is broken, the distributed optical fiber sensing system is controlled to operate in a second mode, and the first optical switch module 9 is controlled to remove the input optical signal from the first optical switch module 9 The sixth output port A27 is output to control the second optical switch module 10 to output the input optical signal from the eighth output port A30 of the second optical switch module.

The distributed optical fiber sensing system shown in FIG. 10 is taken as an example to explain the present application. The working process of the system shown in Figure 10 is as follows:

a) The signal light output by the laser 101 is divided into two paths by the first coupler 102: the two continuous lights obtained are respectively used as the detection signal light (A12 port output) and the pump light (A13 port output) in the BOTDA mode. Eigen light (A12 port output) and detection signal light (A13 port output) as BOTDR;

b) After the BOTDA pump light / BOTDR detection light passes through the optical signal pulse modulation module 104, the continuous light is modulated into a pulsed optical signal, and then enters the second wavelength division multiplexer 8 through the optical circulator 2 and enters the sensor Fiber Optic F.

c) The BOTDA detection light / BOTDR intrinsic light is moved to the original carrier frequency by the optical signal sweep module 103, and then enters the input port A25 of the first optical switch module 9.

d) The BOTDA detection optical signal / BOTDR detection optical signal carrying information at various positions of the sensing fiber (unlike the BOTDA detection optical signal, the BOTDR detection optical signal is a self-published Brillouin light backscattered by the fiber) via the optical circulator 2 Enter the second optical switch module 10.

When the system switches to the BOTDA mode, the output port A29 of the second optical switch module 10 functions and is connected to the input port A33 of the first filter module, and the BOTDA detection light enters the light detection module 14;

When the system switches to the BOTDR mode, the output port A30 of the second optical switch module 10 functions and is connected to the input port A35 of the second filter module. The BOTDR detection optical signal passes through the second optical switch module 10 and the second filter module 13 Enter the second coupler 11, then perform coherent beat frequency with the BOTDR intrinsic optical signal, and finally enter the optical detection module 14.

e) The optical detection module 14 converts the optical signal into an electrical signal, which is finally received and analyzed by the data acquisition processing and system control module 5.

The different modes are explained below. First, the working process in BOTDA mode is explained.

As shown in FIG. 11a, in the BOTDA mode, the output port A26 of the first optical switch module 9 functions. At this time, the first optical switch module 9 is connected to the input port A14 of the first wavelength division multiplexer 6, and BOTDA detects the signal light. Enter the sensing fiber 20; the output port A29 of the second optical switch module 10 functions, at this time the second optical switch module 10 is connected to the first filter module 12, the BOTDA detection signal light passes through the second optical switch module 10, the first filter The module 12 enters the light detection module 14;

As shown in FIG. 11a, the optical signal output by the laser 101 is divided into two channels by the first coupler 102, and the two channels of light are respectively used as the detection light (direction A12) and the pumping light (direction A13) of BOTDA. Input to the optical signal frequency sweep module 103; pump light is input to the optical signal pulse modulation module 104;

The detection light moves the frequency of the original carrier through the optical signal sweep module 103, and then enters the input port A25 of the first optical switch module 9. Enter the first wavelength division multiplexer 6 through the first optical switch module 9, and then enter the sensing fiber F;

The pump light passes through the optical signal pulse modulation module 104, the continuous light is modulated into a pulsed optical signal, and then enters the optical circulator 2 from the port A1, and outputs from the port A2 of the optical circulator 2 to the second wavelength division multiplexer 8, enters Sensor fiber 20.

The forward-propagating BOTDA detection light and the back-scattered pump light are output to the second optical switch module 10 through the port A3 of the circulator 2.

The port A29 of the second optical switch module 10 functions and is connected to the input port of the first filter module 12, and the BOTDA detection signal light enters the light detection module 14 through the first filter module 12;

The optical detection module 14 converts the optical signal into an electrical signal, and the electrical signal is finally received by the data collection processing and system control module 5 for processing and analysis.

Next, the working process in BOTDR mode will be explained.

As shown in FIG. 11b, in the BOTDR mode, the output port A27 of the first optical switch module 9 functions. At this time, the first optical switch module 9 is connected to the second coupler 11, and the BOTDR intrinsic light enters the second coupler 11. The output port A30 of the second optical switch module 10 functions. At this time, the second optical switch and the module 10 are connected to the second filter module 13 and then to the second coupler 11. The BOTDR detection optical signal passes through the second optical switch module 13 2. The second filter module 13 enters the second coupler 11, and then performs coherent beat frequency with the BOTDR intrinsic optical signal, and finally enters the light detection module 33.

The working process in BOTDR mode is described in detail below.

The optical signal output by the laser 101 is divided into two channels by the first coupler 102, one channel as the intrinsic light of the BOTDR and input to the optical signal frequency sweep module 103, and one channel as the detection light of the BOTDR and input to the optical signal pulse modulation module 104;

After the detection light of the BOTDR passes through the optical signal pulse modulation module 104, the continuous light is modulated into a pulsed optical signal, and then enters the second wavelength division multiplexer 8 through the optical circulator 2 and then enters the sensing optical fiber.

The eigen light of the BOTDR is moved to the frequency of the original carrier by the optical signal frequency sweep module 103, and then enters the first optical switch module 9. The output port A27 of the first optical switch module functions and is connected to the input port of the second coupler 11, and the BOTDR intrinsic light enters the second coupler 11.

The BOTDR detection light carrying information at various positions of the sensing fiber (unlike BOTDA, where the BOTDR detection light is a self-published Brillouin light backscattered by the fiber) enters the second optical switch module 10 via the optical circulator. The output port A30 of the second optical switch module functions and is connected to the input port of the second filter module 13, the BOTDR detection light enters the second coupler 11 through the second filter module 13, and then performs a coherent shot with the BOTDR intrinsic light Frequency, and finally enter the light detection module 14.

The optical detection module 14 converts the optical signal into an electrical signal, and is finally received and processed by the data collection processing and system control module 5 for analysis.

Among them, the switching between BOTDA mode and BOTDR mode is based on whether fiber breakage occurs. When the state of the sensing fiber is normal (no fiber breakage), the system works in BOTDA mode. When the sensor fiber breaks, the system works In BOTDR mode.

As shown in FIG. 12, the method for controlling the distributed optical fiber sensing system shown in FIG. 10 provided by an embodiment of the present application includes: steps 1201 to 1209.

In step 1201, the data collection processing and system control module 5 collects electrical signals converted from the light detection module 14 received at each moment.

In step 1202, when there is a large change in voltage amplitude (it should be pointed out that during normal operation, the system is in BOTDA mode, so that the optical detection module receives a continuous detection optical signal, if the optical fiber link is sensed at a certain time A fiber breakage occurs at a certain position, which will cause the continuous detection optical signal to fail to pass to the optical detection module. At this time, the optical detection module receives a very weak backscattered optical signal of the pulsed optical signal) Set value, go to step 1203, otherwise, go to step 1201.

In step 1203, it is judged that the sensor fiber link is broken at this time, and the sampled signals at the time of the sudden drop and the time before the sudden drop are compared and analyzed to determine the distance between the position of the broken fiber and the incident end, and the distributed optical fiber sensing system is closed. .

In step 1204, the working mode of the distributed optical fiber sensing system is switched from the BOTDA mode to the BOTDR mode.

Performing mode switching includes: turning off the optical signal frequency sweep module 103, and adjusting the data acquisition and processing and the signal analysis and processing method of the system control module (analysis and processing method corresponding to the BOTDR mode).

In step 1205, adjust the working state of the device (adjust the device parameters) according to the distance between the fiber break position and the incident end.

For example, the parameters of the laser 101 are adjusted. When there is a distributed optical amplification module, the parameters of the distributed optical amplification module are also adjusted. By adjusting the parameters according to the distance, the accuracy of the measurement results can be further improved.

In step 1206, the distributed optical fiber sensing system is restarted according to the new device parameter settings.

In step 1207, perform a validity analysis on the received signal in the BOTDR mode: if the signal is normal, go to step 1208, if the signal is abnormal, go to step 1209.

In step 1208, report the first information and end; for example, report "the fiber breakage position is at x, xxx km, and the system has switched to the BOTDR mode, and will continue to monitor the 0 ~ x, xxx km sensor fiber."

In step 1209, "system failure" is reported to end.

It should be noted that the control method shown in FIG. 6 can also be used.

As shown in FIG. 13, an embodiment of the present application provides a control device 130 including a memory 131 and a processor 132. The memory 131 stores a program, and the program is implemented when read and executed by the processor 132 The control method described in any embodiment.

As shown in FIG. 14, an embodiment of the present application provides a computer-readable storage medium 140. The computer-readable storage medium 140 stores one or more programs 141, and the one or more programs 141 may be used by one or Multiple processors execute to implement the control method described in any embodiment.

Those of ordinary skill in the art may understand that all or some of the steps, systems, and functional modules / units in the method disclosed above may be implemented as software, firmware, hardware, and appropriate combinations thereof. In a hardware implementation, the division between the functional modules / units mentioned in the above description does not necessarily correspond to the division of physical components; for example, one physical component may have multiple functions, or one function or step may be composed of several physical The components are executed in cooperation. Some or all components may be implemented as software executed by a processor, such as a digital signal processor or microprocessor, or as hardware, or as an integrated circuit, such as an application specific integrated circuit. Such software may be distributed on computer-readable media, which may include computer storage media (or non-transitory media) and communication media (or transitory media). As is well known to those of ordinary skill in the art, the term computer storage media includes both volatile and nonvolatile implemented in any method or technology for storing information such as computer readable instructions, data structures, program modules, or other data Sex, removable and non-removable media. Computer storage media include but are not limited to Random Access Memory (RAM), Read-Only Memory (ROM), Electrically Erasable Programmable Read-Only Memory (Electrically Erasable Programmable Read Only Memory, EEPROM) , Flash memory or other memory technology, CD-ROM (Compact Disc Read-Only Memory, CD-ROM), Digital Versatile Disc (DVD) or other disc storage, magnetic box, tape, disk storage or other magnetic storage A device, or any other medium that can be used to store desired information and can be accessed by a computer. In addition, it is well known to those of ordinary skill in the art that the communication medium generally contains computer readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transmission mechanism, and may include any information delivery medium .

Claims (21)

1. A distributed optical fiber sensing system includes: an optical generation module, an optical circulator, a filter module, an optical detection module, a data acquisition processing and a system control module, wherein the optical circulator includes a first port in a sequential relationship, The second port and the third port, the light generating module includes a first output port and a second output port, the second output port of the light generating module is connected to the first port of the optical circulator, the optical ring The third port of the filter is connected to the input port of the filter module, the output port of the filter module is connected to the input port of the light detection module, and the output port of the light detection module is connected to the data acquisition processing and system Control module, in which:

   The light generating module is configured to output a swept optical signal through a first output port of the light generating module and a second output port of the light generating module according to the data collection processing and control of the system control module Pulsed optical signal; or, output the pulsed optical signal only through the second output port of the light generating module;

   The optical circulator is configured to output the input optical signal from the next port corresponding to the input port of the optical circulator;

   The filtering module is configured to filter the input optical signal and output it to the optical detection module;

   The optical detection module is configured to convert the input optical signal into an electrical signal and output the electrical signal to the data collection processing and system control module;

   The data collection processing and system control module is configured to determine the state of the sensing optical fiber, control the distributed optical fiber sensing system to work in a working mode corresponding to the state of the sensing optical fiber, and, according to the input electrical signal And the current working mode determines the target information.
2. The system according to claim 1, wherein the data collection processing and system control module is configured to determine the state of the sensing fiber by: determining whether the sensing fiber is broken according to the change of the electrical signal.
3. The system according to claim 1, wherein the data collection processing and system control module is configured to control the distributed optical fiber sensing system to operate in a working mode corresponding to the state of the sensing optical fiber by:

   When the sensing optical fiber is not broken, control the distributed optical fiber sensing system to work in a first mode, and control the light generating module to output the swept optical signal and the pulsed optical signal;

   In the case where the sensing optical fiber is broken, the distributed optical fiber sensing system is controlled to work in the second mode, and the light generating module is controlled to output only the pulsed optical signal.
4. The system according to claim 1, wherein the data collection processing and system control module is further configured to determine the fiber breakage position of the sensing optical fiber according to the change of the electrical signal.
5. The system according to claim 4, wherein the data acquisition processing and system control module is further configured to adjust device parameters of the distributed optical fiber sensing system according to the fiber breakage position.
6. The system according to claim 1, wherein the light generating module includes a laser, a first coupler, an optical signal sweep module and an optical signal pulse modulation module, the first coupler includes an input port and two output ports, The laser is connected to an input port of the first coupler, an output port of the first coupler is connected to the optical signal frequency sweep module, and another output port of the first coupler is connected to the Optical signal pulse modulation module, the output port of the optical signal sweep module is the first output port of the light generation module, and the output port of the optical signal pulse modulation module is the second output of the light generation module Port, where,

   The laser is configured to generate an optical signal and output the optical signal to the first coupler;

   The first coupler is configured to divide the input optical signal into two channels, one channel is output to the optical signal frequency sweep module, and the other channel is output to the optical signal pulse modulation module;

   The optical signal frequency sweeping module is configured to modulate the input optical signal into a frequency sweeping optical signal and output it through the first output port;

   The optical signal pulse modulation module is configured to convert the input optical signal into a pulsed optical signal and output it through the second output port.
7. The system according to any one of claims 1 to 6, wherein the distributed optical fiber sensing system further includes an amplifying device, wherein:

   The amplification device includes a first wavelength division multiplexer, a distributed optical amplification module, and a second wavelength division multiplexer. The first wavelength division multiplexer includes a first input port and a second input port, and, one Output port; the second wavelength division multiplexer includes a third input port and a fourth input port, and, an output port, the distributed optical amplification module includes a third output port and a fourth output port, the optical The first output port of the generation module is connected to the first input port of the first wavelength division multiplexer, and the third output port of the distributed optical amplifier module is connected to the second output port of the first wavelength division multiplexer Input port, the fourth output port of the distributed optical amplifier module is connected to the fourth input port of the second wavelength division multiplexer, and the second port of the optical circulator is connected to the second wavelength division multiplexer The third input port of the user;

   Or, the amplification device includes a first wavelength division multiplexer and a distributed optical amplification module, the first wavelength division multiplexer includes a first input port and a second input port, and an output port; the optical The first output port of the generation module is connected to the first input port of the first wavelength division multiplexer, and the output port of the distributed optical amplification module is connected to the second input port of the first wavelength division multiplexer ;

   or,

   The amplification device includes a distributed optical amplification module and a second wavelength division multiplexer, the second wavelength division multiplexer includes a third input port and a fourth input port, and, an output port, the distributed optical The output port of the amplification module is connected to the fourth input port of the second wavelength division multiplexer, and the second port of the optical circulator is connected to the third input port of the second wavelength division multiplexer.
8. A distributed optical fiber sensing system includes: a light generation module, an optical circulator, a first filter module, a second filter module, a light detection module, a data acquisition processing and system control module, a second coupler, and a first optical switch Module, a second optical switch module, wherein the optical circulator includes a first port, a second port, and a third port in a sequential relationship, and the light generation module includes a first output port and a second output port, the The second coupler includes an output port and two input ports, the first optical switch module includes an input port, a fifth output port, and a sixth output port, and the second optical switch module includes an input port, a seventh output port, and An eighth output port, the first output port of the light generating module is connected to the input port of the first optical switch module, and the sixth output port of the first optical switch module is connected to a first of the second coupler The input port, the output port of the second coupler is connected to the input port of the light detection module, the output port of the light detection module is connected to the data acquisition processing and system control module; Two output ports are connected to the first port of the optical circulator, a third port of the optical circulator is connected to the input port of the second optical switch module, and a seventh output port of the second optical switch module is connected To one end of the first filter module, the other end of the first filter module is connected to the input port of the light detection module, and the eighth output port of the second optical switch module is connected to the second filter module One end of the second filter module is connected to the other input port of the second coupler, wherein:

   The light generating module is configured to output a swept frequency optical signal through the first output port of the light generating module and a pulsed optical signal through the second output port of the light generating module;

   The optical circulator is configured to output the input optical signal from the next port corresponding to the input port of the optical circulator;

   The first filter module is configured to filter the input optical signal and output it to the light detection module;

   The second filtering module is configured to filter the input optical signal and output it to the second coupler;

   The first optical switch module is configured to output the input optical signal from the fifth output port of the first optical switch module according to the data collection processing and control of the system control module, or from the first The sixth output port of the optical switch module outputs;

   The second optical switch module is configured to output the input optical signal from the seventh output port of the second optical switch module according to the data collection processing and the control of the system control module, or from the second The eighth output port of the optical switch module;

   The second coupler is configured to coherently beat the optical signal input from one input port of the second coupler and the optical signal input from another input port of the second coupler to output to all The light detection module;

   The optical detection module is configured to convert the input optical signal into an electrical signal and output the electrical signal to the data collection processing and system control module;

   The data collection processing and system control module is configured to determine the state of the sensing optical fiber, control the distributed optical fiber sensing system to work in a working mode corresponding to the state of the sensing optical fiber, and, according to the input electrical signal And the current working mode determines the target information.
9. The system according to claim 8, wherein the data collection processing and system control module is configured to determine the state of the sensing optical fiber by determining whether the sensing optical fiber is broken according to the change of the electrical signal.
10. The system according to claim 9, wherein the data collection processing and system is configured to control the distributed optical fiber sensing system to work in a working mode corresponding to the state of the sensing optical fiber through the following manner:

    When the sensing optical fiber is not broken, the distributed optical fiber sensing system is controlled to operate in a first mode, and the first optical switch module is controlled to input the optical signal from the fifth of the first optical switch module. Output port output, controlling the second optical switch module to output the input optical signal from the seventh output port of the second optical switch;

    When the sensing optical fiber is broken, control the distributed optical fiber sensing system to work in the second mode, and control the first optical switch module to input the optical signal from the sixth of the first optical switch module. The output port outputs, controlling the second optical switch module to output the input optical signal from the eighth output port of the second optical switch module.
11. The system according to claim 8, wherein the data collection processing and system control module is further configured to determine the fiber breakage position of the sensing optical fiber according to the change of the electrical signal.
12. The system according to claim 11, wherein the data collection processing and system control module is further configured to adjust device parameters of the distributed optical fiber sensing system according to the fiber cut position.
13. The system according to claim 8, wherein the light generating module includes a laser, a first coupler, an optical signal sweep module and an optical signal pulse modulation module, the laser is connected to an input port of the first coupler, An output port of the first coupler is connected to the optical signal frequency sweep module, another output port of the first coupler is connected to the optical signal pulse modulation module, the output of the optical signal frequency sweep module The port is the first output port of the light generation module, and the output port of the optical signal pulse modulation module is the second output port of the light generation module, wherein:

    The laser is configured to generate an optical signal and output the optical signal to the first coupler;

    The first coupler is configured to divide the input optical signal into two channels, one channel is output to the optical signal frequency sweep module, and the other channel is output to the optical signal pulse modulation module;

    The optical signal frequency sweeping module is configured to modulate the input optical signal into a frequency sweeping optical signal and output it through the first output port;

    The optical signal pulse modulation module is configured to convert the input optical signal into a pulsed optical signal and output it through the second output port.
14. The system according to any one of claims 8 to 13, wherein the distributed optical fiber sensing system further includes an amplifying device, wherein:

    The amplification device includes a first wavelength division multiplexer, a distributed optical amplification module, and a second wavelength division multiplexer. The first wavelength division multiplexer includes a first input port and a second input port, and, one Output port; the second wavelength division multiplexer includes a third input port and a fourth input port, and, an output port, the distributed optical amplifier module includes a third output port and a fourth output port, the first A fifth output port of an optical switch module is connected to the first input port of the first wavelength division multiplexer, and a second input port of the first wavelength division multiplexer is connected to the A third output port, the fourth output port of the distributed optical amplifier module is connected to the fourth input port of the second wavelength division multiplexer, and the second port of the optical circulator is connected to the second wave The third input port of the demultiplexer;

    Or, the amplification device includes a first wavelength division multiplexer and a distributed optical amplification module, the first wavelength division multiplexer includes a first input port and a second input port, and an output port; the first A fifth output port of an optical switch module is connected to the first input port of the first wavelength division multiplexer, and an output port of the distributed optical amplifier module is connected to a second of the first wavelength division multiplexer Input port

    or,

    The amplification device includes a distributed optical amplification module and a second wavelength division multiplexer, the second wavelength division multiplexer includes a third input port and a fourth input port, and, an output port, the distributed optical The output port of the amplification module is connected to the fourth input port of the second wavelength division multiplexer, and the second port of the optical circulator is connected to the third input port of the second wavelength division multiplexer.
15. A control method of a distributed optical fiber sensing system according to any one of claims 1 to 14, comprising:

    The state of the sensing optical fiber is determined, and the distributed optical fiber sensing system is controlled to work in a working mode corresponding to the state of the sensing optical fiber.
16. The method according to claim 15, wherein the determining the state of the sensing optical fiber comprises: judging whether the sensing optical fiber is broken according to a change in an electrical signal collected by a data collection process and a system control module.
17. The method according to claim 16, wherein the judging whether the sensing optical fiber is broken according to the change of the collected electrical signal comprises:

    When the change of the collected electrical signal is greater than or greater than or equal to a preset value, it is determined that there is fiber breakage.
18. The method according to claim 16, further comprising: determining a fiber break position according to the change of the collected electrical signal.
19. The method according to claim 18, after determining the fiber breakage position according to the change of the electrical signal, further comprising: adjusting device parameters of the distributed optical fiber sensing system according to the fiber breakage position.
20. A control device includes a memory and a processor. The memory stores a program, and when the program is read and executed by the processor, the control method according to any one of claims 15 to 19 is implemented.
21. A computer-readable storage medium, wherein the computer-readable storage medium stores at least one program, and the at least one program is executable by at least one processor to implement any one of claims 15 to 19. Control Method.

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