Fiber bragg grating tunnel structure vibration monitoring system

Abstract

The utility model relates to a fiber bragg grating tunnel structure vibration monitoring system, which relates to the field of tunnel monitoring technology, and comprises a mounting net, a vibration fiber bragg grating detection chain, a demodulator, a signal processor and a vibration monitoring display, the mounting net is fixedly mounted on the surface of the inner wall of a to-be-monitored tunnel, and the vibration fiber grating detection chain is located between the inner wall of the tunnel and the mounting net; the output end of the vibration fiber grating detection chain is connected with the demodulator, the demodulator outputs vibration characteristic signals, the signal input end of the signal processor is in signal connection with the signal output end of the demodulator, and the signal processor receives the vibration characteristic signals and outputs abnormal vibration position signals when the vibration frequency is too high. The signal input end of the vibration monitoring displayer is in signal connection with the signal output end of the signal processor, and the vibration monitoring displayer receives and displays the vibration position signals. The technical effect of monitoring the vibration of the tunnel structure in real time can be achieved.

Description

Technical Field

[0001] The present application relates to the field of tunnel monitoring technologies, and particularly to an optical fiber grating tunnel structure vibration monitoring system. Background Art

[0002] In railway systems such as high-speed railways, intercity railways, urban rail transit, etc., affected by many factors such as terrain conditions and economic development in various regions, railways inevitably pass through long mountainous areas, urban underground areas, etc. The safety state of railway tunnel structures directly affects the smoothness and safety of train operations. Ensuring good operating conditions of railway tunnels is of great significance for guaranteeing railway operations.

[0003] The safety monitoring of railway tunnels involves many items. Items such as vibration and noise, misalignment between plates, rail breakage, and fastener ejection are all key concerns of operators. The above problems can all be used to achieve early warning through the inversion of monitored vibration data.

[0004] In the prior art, for the monitoring of railway tunnel structure vibrations, it mainly relies on manual regular inspections. This highly depends on manual monitoring, with low efficiency and high monitoring costs. At the same time, the method of manually regularly inspecting railway tunnel structures cannot accurately grasp the health state of railway tunnel structures and cannot achieve early warning, so there are areas for improvement. Utility Model Content

[0005] In order to achieve the technical effect of real-time monitoring of tunnel structure vibrations, the present application provides an optical fiber grating tunnel structure vibration monitoring system.

[0006] The optical fiber grating tunnel structure vibration monitoring system provided by the present application adopts the following technical solutions:

[0007] An optical fiber grating tunnel structure vibration monitoring system includes an installation network, a vibration optical fiber grating detection chain, a demodulator, a signal processor, and a vibration monitoring display. The vibration optical fiber grating detection chain is fixedly installed in an S shape on the installation network. The installation network is fixedly installed on the inner wall surface of the tunnel to be monitored, and the vibration optical fiber grating detection chain is located between the tunnel inner wall and the installation network;

[0008] The output end of the vibration optical fiber grating detection chain is connected to the demodulator. The demodulator outputs vibration characteristic signals. The signal input end of the signal processor is signal-connected to the signal output end of the demodulator. The signal processor receives the vibration characteristic signals and outputs abnormal vibration position signals when the vibration frequency is too high. The signal input end of the vibration monitoring display is signal-connected to the signal output end of the signal processor. The vibration monitoring display receives the vibration position signals and displays them;

[0009] A fiber optic splicing package is connected in series between the demodulator and the vibrating fiber Bragg grating detection chain, and the fiber optic splicing package is fixedly installed on the inner wall of the tunnel;

[0010] A detection chain tension adjusting mechanism is fixedly installed on the inner wall of the tunnel, and the detection chain tension adjusting mechanism is located between the installation net and the fiber optic splicing package.

[0011] By adopting the above technical solution, when the tunnel structure vibrates, the S-shaped vibrating fiber Bragg grating detection chain fixed on the inner wall of the tunnel by the installation net senses the vibration and is demodulated by the demodulator and outputs a vibration characteristic signal. The signal processor analyzes the amplitude and vibration frequency. When the amplitude is too large and the vibration frequency is too high, it is determined that the tunnel structure has abnormal vibration. The signal processor outputs an abnormal vibration position signal and displays it through the vibration monitoring display. The operator can master the abnormal vibration position through the vibration monitoring display, and the technical effects of real-time monitoring of the tunnel structure vibration and calibration of the abnormal vibration position can be achieved. In addition, since the vibrating fiber Bragg grating detection chain is arranged in an S shape on the installation net, and the installation net is fixedly installed on the inner wall of the tunnel, the sensing area of the vibrating fiber Bragg grating detection chain can be effectively increased, the vibration monitoring effect can be improved, and the installation net can stably fix the vibrating fiber Bragg grating detection chain, effectively ensuring the detection accuracy of the vibrating fiber Bragg grating detection chain. The fiber optic splicing package can realize the connection between the main optical fiber of the vibrating fiber Bragg grating detection chain and the demodulator. The tension adjusting mechanism can adjust the tension of the section of the vibrating fiber Bragg grating detection chain between the installation net and the fiber optic splicing package, reducing the situation that the vibrating fiber Bragg grating detection chain loosens and hangs on the inner wall of the tunnel and shakes on the inner wall of the tunnel, affecting the vibration monitoring of the vibrating fiber Bragg grating detection chain.

[0012] Preferably, the detection chain tension adjusting mechanism includes a mounting seat, an airbag is fixedly installed on the mounting seat, and the vibrating fiber Bragg grating detection chain is located on the surface of the airbag;

[0013] A tension sensing member is fixedly installed on the surface of the airbag. The tension sensing member detects the contact pressure between the vibrating fiber Bragg grating detection chain and the surface of the airbag and outputs an induction pressure signal;

[0014] The signal output end of the tension sensing member is signal-connected to a single-chip microcomputer. An air inlet valve is installed on the airbag. The signal output end of the single-chip microcomputer is signal-connected to the signal input end of the air inlet valve. The single-chip microcomputer controls the air inlet valve to inflate the airbag.

[0015] By adopting the above technical solution, when the vibrating fiber Bragg grating detection chain loosens, the contact pressure between the vibrating fiber Bragg grating detection chain and the surface of the airbag increases. The single-chip microcomputer can control the air inlet valve to inflate the airbag, making the airbag expand to support the vibrating fiber Bragg grating detection chain, reducing the situation that the loose vibrating fiber Bragg grating detection chain shakes and affects the vibration monitoring result.

[0016] Preferably, the mounting seat includes two fixing seats which are fixedly mounted on the inner wall of the tunnel;

[0017] An installation rod is fixedly connected between the two fixing seats. An installation hole is formed through the middle of the airbag, and the airbag is installed on the installation rod, and both sides of the airbag are respectively attached to the two fixing seats.

[0018] By adopting the above technical solution, the installation of the airbag can be realized through the installation rod, and the expansion direction of the airbag is restricted by the fixing seats on both sides, so that the vibrating fiber Bragg grating detection chain can be supported when it is loose.

[0019] Preferably, an arc-shaped plate is fixedly connected to the top of the airbag. Two limiting strips are integrally formed on the upper surface of the arc-shaped plate, and a placement groove is formed between the two limiting strips. The vibrating fiber Bragg grating detection chain is located in the placement groove;

[0020] The tension sensing member includes a thin film pressure sensor, and the thin film pressure sensor is located at the bottom of the placement groove.

[0021] By adopting the above technical solution, the placement groove on the arc-shaped plate can limit the position of the vibrating fiber Bragg grating detection chain, and the contact pressure between the vibrating fiber Bragg grating detection chain and the surface of the airbag can be detected through the thin film pressure sensor.

[0022] In summary, the fiber Bragg grating tunnel structure vibration monitoring system of the present application includes at least one of the following beneficial technical effects:

[0023] 1. When the tunnel structure vibrates, the S-shaped vibrating fiber Bragg grating detection chain fixed on the inner wall of the tunnel by the installation net senses the vibration and is demodulated by the demodulator and outputs the vibration characteristic signal. The signal processor analyzes the amplitude and vibration frequency. When the amplitude is too large and the vibration frequency is too high, it is determined that the tunnel structure has abnormal vibration. The signal processor outputs the abnormal vibration position signal and displays it through the vibration monitoring display. The operator can master the abnormal vibration position through the vibration monitoring display, and the technical effects of real-time monitoring of the tunnel structure vibration and calibration of the abnormal vibration position can be achieved;

[0024] 2. Since the vibrating fiber Bragg grating detection chain is arranged in an S shape on the installation net, and the installation net is fixedly installed on the inner wall of the tunnel, the sensing area of the vibrating fiber Bragg grating detection chain can be effectively increased, the vibration monitoring effect can be improved, and the installation net can stably fix the vibrating fiber Bragg grating detection chain, effectively ensuring the detection accuracy of the vibrating fiber Bragg grating detection chain. Description of the Drawings

[0025] Figure 1It is a schematic diagram for showing the overall structure of the vibration monitoring system in an embodiment of the present application.

[0026] Figure 2 It is a schematic diagram for showing the overall structure of the detection chain tension adjusting mechanism in an embodiment of the present application.

[0027] Explanation of reference numerals: 1, mounting net; 2, vibrating fiber Bragg grating detection chain; 3, tunnel to be monitored; 4, fiber optic splicing package; 5, tension adjusting mechanism; 51, mounting base; 511, fixing base; 512, mounting rod; 52, airbag; 521, inflation valve; 522, arc plate; 523, limiting strip; 524, placement groove; 6, thin film pressure sensor. Detailed implementation manners

[0028] The following will Figure 1-2 further elaborate on the present application in detail.

[0029] Embodiment

[0030] An embodiment of the present application discloses an optical fiber grating tunnel structure vibration monitoring system. Referring to Figure 1 and Figure 2 , it mainly includes a mounting net 1, a vibrating fiber Bragg grating detection chain 2, a demodulator, a signal processor, and a vibration monitoring display. The vibrating fiber Bragg grating detection chain 2 is fixedly installed on the mounting net 1 in an S shape. The mounting net 1 is fixedly installed on the inner wall surface of the tunnel 3 to be monitored, and the vibrating fiber Bragg grating detection chain 2 is located between the tunnel inner wall and the mounting net 1.

[0031] The output end of the vibrating fiber Bragg grating detection chain 2 is connected to the demodulator. The demodulator outputs vibration characteristic signals. The signal input end of the signal processor is signal-connected to the signal output end of the demodulator. The signal processor receives the vibration characteristic signals and outputs abnormal vibration position signals when the vibration occurrence frequency is too high. The signal input end of the vibration monitoring display is signal-connected to the signal output end of the signal processor. The vibration monitoring display receives the vibration position signals and displays them.

[0032] A fiber optic splicing package 4 is connected in series between the demodulator and the vibrating fiber Bragg grating detection chain 2. The fiber optic splicing package 4 is fixedly installed on the tunnel inner wall; a detection chain tension adjusting mechanism 5 is fixedly installed on the tunnel inner wall, and the detection chain tension adjusting mechanism 5 is located between the mounting net 1 and the fiber optic splicing package 4.

[0033] When the tunnel structure vibrates, the S-shaped vibrating fiber Bragg grating detection chain 2 fixed on the inner wall of the tunnel through the installation net 1 senses the vibration, demodulates it through a demodulator and outputs a vibration characteristic signal. The signal processor analyzes the amplitude and vibration frequency. When the amplitude is too large and the vibration frequency is too high, it determines that the tunnel structure has abnormal vibration. The signal processor outputs an abnormal vibration position signal and displays it through a vibration monitoring display. The operator can master the abnormal vibration position through the vibration monitoring display, and the technical effects of real-time monitoring of the tunnel structure vibration and calibration of the abnormal vibration position can be achieved.

[0034] In addition, since the vibrating fiber Bragg grating detection chain 2 is arranged in an S shape on the installation net 1, and the installation net 1 is fixedly installed on the inner wall of the tunnel, it can effectively increase the sensing area of the vibrating fiber Bragg grating detection chain 2 and improve the vibration monitoring effect. Moreover, the installation net 1 can stably fix the vibrating fiber Bragg grating detection chain 2, effectively ensuring the detection accuracy of the vibrating fiber Bragg grating detection chain 2. The optical fiber splicing package 4 can realize the connection between the main optical fiber of the vibrating fiber Bragg grating detection chain 2 and the demodulator. The tension adjusting mechanism 5 can adjust the tension of the section of the vibrating fiber Bragg grating detection chain 2 between the installation net 1 and the optical fiber splicing package 4, reducing the situation that the vibrating fiber Bragg grating detection chain 2 loosens and hangs on the inner wall of the tunnel and sways on the inner wall of the tunnel, affecting the vibration monitoring of the vibrating fiber Bragg grating detection chain 2.

[0035] It should be noted that in the embodiment of the present application, the end of the vibrating fiber Bragg grating detection chain 2 is connected to a pump light source fixedly installed on the inner wall of the tunnel in advance, which will not be elaborated here.

[0036] Among them, the installation net 1 is a metal net. The metal net is fixed on the surface of the inner wall of the tunnel through several expansion bolts, and the vibrating fiber Bragg grating detection chain 2 is fixed on the surface of the metal net through staples.

[0037] Refer to Figure 2 , the detection chain tension adjusting mechanism 5 includes a mounting seat 51. An airbag 52 is fixedly installed on the mounting seat 51, and the vibrating fiber Bragg grating detection chain 2 is located on the surface of the airbag 52; a tension sensing member is fixedly installed on the surface of the airbag 52. The tension sensing member detects the contact pressure between the vibrating fiber Bragg grating detection chain 2 and the surface of the airbag 52 and outputs an induced pressure signal; the signal output end of the tension sensing member is signal-connected to a single-chip microcomputer. An air inflation valve 521 is installed on the airbag 52, and the signal output end of the single-chip microcomputer is signal-connected to the signal input end of the air inflation valve 521. The single-chip microcomputer controls the air inflation valve 521 to inflate the airbag 52.

[0038] By adopting the above technical solution, when the vibrating fiber Bragg grating detection chain 2 becomes loose, the contact pressure between the vibrating fiber Bragg grating detection chain 2 and the surface of the airbag 52 increases. The single-chip microcomputer can control the inflation valve 521 to inflate the airbag 52, so that the airbag 52 expands to support the vibrating fiber Bragg grating detection chain 2, and the situation that the loose vibrating fiber Bragg grating detection chain 2 sways and affects the vibration monitoring result can be reduced.

[0039] Refer to Figure 2 , the mounting seat 51 includes two fixing seats 511, and the two fixing seats 511 are fixedly installed on the inner wall of the tunnel; an installation rod 512 is fixedly connected between the two fixing seats 511. An installation hole is formed through the middle of the airbag 52, and the airbag 52 is installed on the installation rod 512, and both sides of the airbag 52 are respectively attached to the two fixing seats 511.

[0040] The installation of the airbag 52 can be realized through the installation rod 512, and the expansion direction of the airbag 52 is restricted by the fixing seats 511 on both sides, so that the airbag 52 can support the vibrating fiber Bragg grating detection chain 2 when the vibrating fiber Bragg grating detection chain 2 becomes loose.

[0041] Refer to Figure 2 , an arc-shaped plate 522 is fixedly connected to the top of the airbag 52. Two limiting strips 523 are integrally formed on the upper surface of the arc-shaped plate 522, and a placement groove 524 is formed between the two limiting strips 523. The vibrating fiber Bragg grating detection chain 2 is located in the placement groove 524; the tension sensing member includes a thin film pressure sensor 6, and the thin film pressure sensor 6 is located at the bottom of the placement groove 524.

[0042] By adopting the above technical solution, the placement groove 524 on the arc-shaped plate 522 can limit the position of the vibrating fiber Bragg grating detection chain 2, and the contact pressure between the vibrating fiber Bragg grating detection chain 2 and the surface of the airbag 52 can be detected through the thin film pressure sensor 6.

[0043] The implementation principle of a fiber Bragg grating tunnel structure vibration monitoring system in an embodiment of the present application is as follows: when the tunnel structure vibrates, the S-shaped vibrating fiber Bragg grating detection chain 2 fixed on the inner wall of the tunnel through the installation net 1 senses the vibration and is demodulated by a demodulator and outputs a vibration characteristic signal. The signal processor analyzes the amplitude and vibration frequency. When the amplitude is too large and the vibration frequency is too high, it is determined that the tunnel structure has abnormal vibration. The signal processor outputs an abnormal vibration position signal and displays it through a vibration monitoring display. The operator can master the abnormal vibration position through the vibration monitoring display, and the technical effects of real-time monitoring of the tunnel structure vibration and calibration of the abnormal vibration position can be achieved.

[0044] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited accordingly. Therefore, all equivalent changes made according to the structure, shape, and principle of the present application should be covered within the protection scope of the present application.

Claims

1. A fiber Bragg grating tunnel structure vibration monitoring system, characterized in that: The invention comprises a mounting net (1), a vibration fiber Bragg grating detection chain (2), a demodulator, a signal processor and a vibration monitoring display, wherein the vibration fiber Bragg grating detection chain (2) is fixedly mounted on the mounting net (1) in an S shape, the mounting net (1) is fixedly mounted on the inner wall surface of a tunnel (3) to be monitored, and the vibration fiber Bragg grating detection chain (2) is located between the inner wall of the tunnel and the mounting net (1); The output end of the vibration fiber Bragg grating detection chain (2) is connected to the demodulator, the demodulator outputs a vibration characteristic signal, the signal input end of the signal processor is connected to the signal output end of the demodulator, the signal processor receives the vibration characteristic signal and outputs an abnormal vibration position signal when the vibration frequency is too high, the signal input end of the vibration monitoring display is connected to the signal output end of the signal processor, and the vibration monitoring display receives the vibration position signal and displays it; An optical fiber fusion splicing package (4) is connected in series between the demodulator and the vibrating optical fiber grating detection chain (2), and the optical fiber fusion splicing package (4) is fixedly installed on the inner wall of the tunnel; A detection chain tension adjustment mechanism (5) is fixedly installed on the inner wall of the tunnel, and the detection chain tension adjustment mechanism (5) is located between the installation net (1) and the optical fiber fusion package (4).

2. A fiber Bragg grating tunnel structure vibration monitoring system according to claim 1, characterized in that: The detection chain tension adjustment mechanism (5) comprises a mounting seat (51), an airbag (52) is fixedly mounted on the mounting seat (51), and the vibrating fiber grating detection chain (2) is located on the surface of the airbag (52); A tension sensing component is fixedly mounted on the surface of the airbag (52), and the tension sensing component detects the contact pressure between the vibrating fiber grating detection chain (2) and the surface of the airbag (52) and outputs a sensing pressure signal; The signal output end of the tension sensing element is signal-connected to a single-chip microcomputer, an inflation valve (521) is installed on the airbag (52), the signal output end of the single-chip microcomputer is signal-connected to the signal input end of the inflation valve (521), and the single-chip microcomputer controls the inflation valve (521) to inflate the airbag (52).

3. A fiber Bragg grating tunnel structure vibration monitoring system according to claim 2, characterized in that: The mounting seat (51) comprises two fixing seats (511), and the two fixing seats (511) are fixedly mounted on the inner wall of the tunnel; A mounting rod (512) is fixedly connected between the two fixing seats (511), a mounting hole is provided through the middle of the airbag (52), the airbag (52) is mounted on the mounting rod (512), and two sides of the airbag (52) are respectively in contact with the two fixing seats (511).

4. A fiber Bragg grating tunnel structure vibration monitoring system according to claim 3, characterized in that: The top of the airbag (52) is fixedly connected with an arc-shaped plate (522), the upper surface of the arc-shaped plate (522) is integrally formed with two limit strips (523), a placement groove (524) is formed between the two limit strips (523), and the vibrating fiber grating detection chain (2) is located in the placement groove (524); The tension sensing component comprises a thin film pressure sensor (6), and the thin film pressure sensor (6) is located at the bottom of the placement groove (524).

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