A signal capture system and tunnel health detection system

Abstract

The present invention discloses a signal capture system, comprising: individual fiber grating (FBG) sensors or a distributed array thereof, and a fiber grating (FBG) demodulator, wherein the fiber grating (FBG) demodulator is connected to the fiber grating (FBG) sensors or the array thereof via a signal transmission optical fiber cable; wherein the individual sensors or the array are installed in a tunnel and / or on an artificial object set up in the tunnel, and the fiber grating sensors or the distributed array sense the environmental parameters of the tunnel and / or the state parameters of the artificial object set up in the tunnel, and transmit the sensing signal to the fiber grating demodulator via a signal transmission optical fiber cable. The above-mentioned system uses optical signals for transmission and has strong anti-interference ability. It is simple to deploy on site and is suitable for long-term and long-distance signal transmission. It is not necessary to set up control equipment on site, and it is not necessary to provide a dedicated power supply for the fiber grating sensor. The acquisition and transmission process is not affected by the complex electromagnetic environment in the tunnel. The present invention further discloses a tunnel health detection system.

Description

Technical Field

[0001] The present invention relates to the technical field of rail transit mid-section tunnel monitoring, and in particular to a signal capture system and a tunnel health detection system. Background Art

[0002] Rail transit systems include numerous tunnels. Tunnel safety and the efficient operation of tunnel equipment are crucial for the smooth operation of the entire system. Therefore, timely monitoring of the health of tunnels and the man-made structures within them is crucial to determine whether any safety hazards exist.

[0003] Taking tunnel fans as an example, existing online monitoring systems can monitor vibration and looseness of fans, brackets, bolts, and other components in real time, enabling fault analysis and early warning protection. Electrical measurement methods use strain gauge resistors, which have low accuracy, poor anti-interference capabilities, and a short lifespan. They also require on-site power and are difficult to transmit signals over long distances, making them unsuitable for long-term monitoring. This requires on-site control equipment for data collection and analysis, with the results uploaded to a control center via Ethernet. However, this control center lacks data analysis and processing capabilities.

[0004] In view of this, how to provide a signal capture system and tunnel health detection system with strong anti-interference ability, long life, quick and easy deployment and suitable for long-term long-distance centralized monitoring has become a technical problem that technical personnel in this field urgently need to solve. Summary of the Invention

[0005] The present invention provides a signal capture system with strong anti-interference capability, long service life, simple on-site deployment, and suitable for long-term remote centralized monitoring, as well as a tunnel health detection system that analyzes the captured signals to obtain tunnel health information.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] A signal capture system, comprising:

[0008] Fiber Bragg grating (FBG) sensors or distributed arrays thereof, and a fiber Bragg grating (FBG) interrogator, wherein the fiber Bragg grating (FBG) interrogator is connected to the fiber Bragg grating (FBG) sensors or the arrays thereof via signal transmission optical fiber cables;

[0009] The individual sensors or arrays are installed in the tunnel and / or on man-made objects in the tunnel, and the fiber grating sensors or the distributed arrays sense the environmental parameters of the tunnel and / or the state parameters of man-made objects in the tunnel, and transmit the sensing signals to the fiber grating demodulator via a signal transmission optical fiber cable.

[0010] Preferably, the fiber Bragg grating sensor is one or more of a fiber Bragg grating tension sensor, a fiber Bragg grating temperature sensor, a fiber Bragg grating displacement sensor, a fiber Bragg grating gap sensor, and a fiber Bragg grating vibration sensor, and the environmental parameters and / or state parameters correspond to tension parameters, temperature parameters, displacement parameters, gap parameters, and vibration state parameters.

[0011] Preferably, the fiber grating sensor is a coordinated two-dimensional fiber grating vibration pickup, which is arranged on a fan installed in a tunnel and on a supporting structure for installing the fan. The coordinated two-dimensional fiber grating vibration pickup includes a shell, in which two cantilever beams with single-dimensional vibration and equal strength are arranged. The vibration directions of the two cantilever beams with single-dimensional vibration are perpendicular to each other. Fiber gratings are arranged on both cantilever beams with single-dimensional vibration. When the cantilever beams are forced to vibrate, the fiber grating is strained, resulting in a change in the central wavelength of the reflected light of the fiber grating.

[0012] Preferably, the two cantilever beams are respectively arranged on two mutually perpendicular flat plates, the ends of the two flat plates are connected and fixed to each other, and any flat plate is composed of a vibration area and a shell connection area arranged on the side of the vibration area away from the other flat plate, and the shell connection area is fixedly connected to the shell; the vibration areas of the two flat plates are connected to each other, and a slit is provided on the vibration area, and the slit is arranged along the outer contour of the vibration area. The vibrating part formed by the slit on the vibration area constitutes the cantilever beam, and the vibration area is triangular or trapezoidal.

[0013] Preferably, the fiber Bragg grating sensor or the distributed array is connected to a plurality of branch optical paths, each branch optical path is connected to a main optical cable through an optical cable junction box, and the main optical cable connects each branch optical cable to a fiber Bragg grating demodulator.

[0014] Preferably, the fiber Bragg grating demodulator demodulates the laser reflected from the fiber Bragg grating sensor and obtains the wavelength signal of the reflected laser.

[0015] A tunnel health monitoring system, characterized by comprising the above-mentioned signal capture system; a signal processing system connected to the signal capture system; the signal processing system analyzing the safety status of the tunnel and / or the man-made objects installed in the tunnel based on the acquired environmental parameters of the tunnel and / or the status parameters of the man-made objects installed in the tunnel.

[0016] Preferably, when the state parameter is a vibration state parameter, a characteristic spectrum of the vibration of the artificial object is obtained based on the vibration state parameter, and the vibration spectrum is trended to obtain the current state of the artificial object and the remaining safe life.

[0017] Preferably, the signal capture system and the signal processing system are remotely connected via a wired or wireless manner.

[0018] The beneficial effects of the present invention are: it is applicable to various monitoring medium conditions of tunnels and various man-made objects in tunnels; it has excellent environmental adaptability and wavelength-temperature mutual compensation; the data acquisition network can adapt to various networking methods; it has scalability and compatibility, can be expanded according to the needs of detection data, can monitor the interval tunnel equipment and structural engineering in real time online, and can use big data to analyze structural health trends; it serves as an important part of the construction of smart stations. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural diagram of a signal capture system and a tunnel health detection system provided by an embodiment of the present invention;

[0020] Figure 2 This is a schematic structural diagram of a coordinated dual-dimensional fiber Bragg grating vibration pickup provided by an embodiment of the present invention, which is arranged on a fan and a support structure;

[0021] Figure 3 Schematic diagram of the structure of the cantilever beam in the coordinated dual-dimensional fiber Bragg grating vibration pickup provided by an embodiment of the present invention;

[0022] Figure 4 yes Figure 3 Schematic diagram of the structure of the middle cantilever beam.

[0023] Markings in the figure: 1 is the shell, 101 is the connecting groove, 102 is the connecting boss, 103 is the second bolt connecting hole, 2 is the vibration area, 201 is the cantilever beam, 202 is the slit, 203 is the packaging groove, 3 is the fiber Bragg grating, 4 is the shell connecting area, 401 is the first bolt connecting hole, 5 is the mass block connecting column, 6 is the mass block, 7 is the fan, 8 is the bearing platform, and 9 is the coordinated dual-dimensional fiber Bragg grating vibration pickup. DETAILED DESCRIPTION

[0024] The present invention will be described in detail below with reference to the accompanying drawings.

[0025] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0026] Example 1

[0027] See also Figures 1 to 4The embodiments of the present invention partially disclose a signal capture system, comprising: individual fiber Bragg grating sensors or a distributed array composed of the same, and a fiber Bragg grating demodulator, wherein the fiber Bragg grating demodulator is connected to the fiber Bragg grating sensors or the array composed of the same via a signal transmission optical fiber cable; wherein the individual sensors or the array are installed in a tunnel and / or on man-made objects set in the tunnel, the fiber Bragg grating sensors or the distributed array sense environmental parameters of the tunnel and / or state parameters of man-made objects set in the tunnel, and transmit the sensing signals to the fiber Bragg grating demodulator via the signal transmission optical fiber cable.

[0028] In this way, the above-mentioned device is mainly used in the field of rail transportation, and is mainly used in subway and light rail tunnels. It is deployed in the tunnel and on man-made objects in the tunnel based on usage requirements. Man-made objects in the tunnel include buildings, structures and electromechanical equipment. Environmental parameters and state parameters are determined separately based on safety monitoring needs, and can be combined according to actual usage requirements. Specifically, they may include temperature and humidity parameters, strain (displacement) parameters, vibration acceleration parameters, amplitude parameters, etc. The above-mentioned parameters can be collected by corresponding fiber grating sensors. In practice, the vibration parameters of man-made objects are generally collected, that is, the fiber grating vibration sensor is deployed on the man-made object to collect temperature and humidity parameters, strain (displacement) parameters, etc. of the tunnel.

[0029] The above-mentioned signal capture system uses optical signals for transmission, has strong anti-interference ability, long service life, simple on-site deployment and is suitable for long-term long-distance signal transmission. All collected data are directly transmitted to the station or control center equipment through the signal transmission optical fiber cable. There is no need to set up control equipment on site, and there is no need to provide a dedicated power supply for the fiber grating sensor. The collection and transmission process is not affected by the complex electromagnetic environment in the tunnel.

[0030] In this embodiment, the fiber Bragg grating sensor is one or more of a fiber Bragg grating tension sensor, a fiber Bragg grating temperature sensor, a fiber Bragg grating displacement sensor, a fiber Bragg grating gap sensor, and a fiber Bragg grating vibration sensor, and the environmental parameters and / or state parameters correspond to tension parameters, temperature parameters, displacement parameters, gap parameters, and vibration state parameters.

[0031] Thus, the above disclosure discloses the fiber grating sensors with a relatively high usage frequency and the corresponding collected parameters, which is convenient for users to select a combination.

[0032] In this embodiment, the fiber Bragg grating sensor is a coordinated two-dimensional fiber Bragg grating vibration pickup 9, which is arranged on a fan 7 set in a tunnel and on a supporting structure 8 on which the fan is installed. The coordinated two-dimensional fiber Bragg grating vibration pickup 9 senses the vibration parameters of the fan 7 and the supporting structure 8 on which the fan is installed; the coordinated two-dimensional fiber Bragg grating vibration pickup includes a shell, in which two cantilever beams with single-dimensional vibration and equal strength are arranged, and the vibration directions of the two cantilever beams with single-dimensional vibration are perpendicular to each other. Fiber Bragg gratings are arranged on both cantilever beams with single-dimensional vibration. When the cantilever beams are forced to vibrate, strain of the fiber Bragg grating is caused, resulting in a change in the central wavelength of the reflected light of the fiber Bragg grating.

[0033] In this way, the vibration pickup is adjusted so that the natural frequency of the cantilever beam is the same as that of the object being measured, thereby increasing the sensitivity of the vibration pickup by resonating with the object being measured. A fiber Bragg grating (FBG) is mounted on the surface of the cantilever beam. The vibration of the object being measured drives the cantilever beam to generate forced vibrations. After the cantilever beam is forced to vibrate, it is subjected to tension and compression with spectral characteristics, which in turn causes the central wavelength of the FBG to change. The FBG wavelength is demodulated into data packets based on time using a fiber Bragg grating demodulator and sent to the server software for data analysis. By interpreting the spectral characteristics of the FBG central wavelength changes, data such as the intensity and severity of the forced vibration of the monitored structure can be obtained. Through software algorithms, the state of the monitored object can be reflected, completing the monitoring of the object being measured. The two cantilever beams can receive vibration waves in two directions simultaneously, and have the function of demodulating the waves generated by the object being measured in two dimensions. The parameter information of the vibration waves in the two dimensions is then monitored separately and coordinated. The vibration of the object being measured is monitored in two dimensions simultaneously.

[0034] The above-mentioned vibration pickup has two-dimensional vibration sensitivity and tunability, which can reduce the cost of the monitoring system and the number of vibration pickups used. It transmits data through fiber optic Bragg gratings and has excellent adaptability to electromagnetic environments. The above-mentioned device can also be buried in concrete structures to adapt to the monitoring of concrete structures or installed on steel structures to complete the monitoring of steel structures; of course, the above-mentioned device can also be used in the field of vibration environment monitoring.

[0035] In this embodiment, the two cantilever beams are respectively arranged on two mutually perpendicular flat plates, and the ends of the two flat plates are connected and fixed to each other. Each flat plate is composed of a vibration area and a shell connection area arranged on the side of the vibration area away from the other flat plate, and the shell connection area is fixedly connected to the shell; the vibration areas of the two flat plates are connected to each other, and slits are provided on the vibration areas. The slits are arranged along the outer contour of the vibration areas. The vibrating parts formed by the slits on the vibration areas constitute the cantilever beams, and the vibration areas are triangular or trapezoidal.

[0036] Thus, it is disclosed how the two cantilever beams can be set to have equal strength through the structure and ensure that forced vibration in two dimensions can be achieved. The structure and materials of the two cantilever beams are exactly the same. The two cantilever beams can be set in an L-shape or a straight line in space. The two flat plates are connected and fixed to achieve the simultaneous forced vibration of the two cantilever beams, that is, they are excited by the same source at the same time. The above structure can better ensure the realization of forced vibration in a single dimensional direction, while effectively limiting vibration in the vertical vibration direction.

[0037] In this embodiment, a mass block 6 is provided on the end of the cantilever beam 201 .

[0038] In this way, the natural frequency of the cantilever beam is adjusted by the mass block 6. The mass block 6 is connected to and fixed on the mass block connecting column 5 provided at the end of the cantilever beam 201. By replacing the mass blocks of different specifications, it is possible to monitor objects of different natural frequencies.

[0039] In this embodiment, the fiber Bragg grating sensor or distributed array is connected to multiple branch optical paths, each branch optical path is connected to the main optical cable through an optical cable junction box, and the main optical cable connects each branch optical cable to the fiber Bragg grating demodulator.

[0040] In this way, it is convenient to arrange multiple fiber grating sensors to form an array, and it is convenient to arrange different types of fiber grating sensors to construct acquisition paths of different parameters.

[0041] In this embodiment, the fiber Bragg grating demodulator demodulates the laser light reflected from the fiber Bragg grating sensor and obtains a wavelength signal of the reflected laser light.

[0042] In this way, using light for signal transmission can effectively resist battery interference.

[0043] A tunnel health monitoring system includes the above-mentioned signal capture system; a signal processing system connected to the signal capture system; the signal processing system analyzes the safety status of the tunnel and / or the man-made objects installed in the tunnel based on the acquired environmental parameters of the tunnel and / or the status parameters of the man-made objects installed in the tunnel.

[0044] There are various methods for determining the installation status based on collected environmental and status parameters. These methods typically compare the collected status and environmental parameters against a preset threshold. If the collected status and environmental parameters exceed the threshold, the system is considered dangerous, and vice versa. Alternatively, all tunnel inspection data along the entire rail transit line is ranked by inspection value, with the top-ranked parameters periodically assigned to a fixed ratio as pending inspection, while the remaining parameters are assigned to the installed state.

[0045] In this embodiment, when the state parameter is a vibration state parameter, a characteristic spectrum of the artificial object's vibration is obtained based on the vibration state parameter, and the vibration spectrum is trended to obtain the current state of the artificial object and the remaining safe life.

[0046] In this way, the sensitivity of a dual-dimensional fiber Bragg grating (FBG) vibration pickup to the wind turbine's vibration frequency is used to determine the characteristic spectrum of the wind turbine's vibration. Trend analysis and data processing of this spectrum's characteristic information reveal the structural safety status. Trend analysis constructs a structural safety evolution model by collecting a large amount of sample data, which serves as a comparison standard. The existing characteristic spectrum is then input into the corresponding data, and the evolution model is used to extrapolate the existing test data to determine the current state of the wind turbine and its remaining lifespan.

[0047] In this embodiment, the signal capture system and the signal processing system are remotely connected via a wired or wireless method.

[0048] In this way, the separation of data collection and data processing is achieved, which better matches the actual adaptation needs and realizes detection networking.

Claims

1. A signal acquisition system, comprising: Fiber Bragg grating (FBG) sensors or distributed arrays thereof, and a fiber Bragg grating (FBG) interrogator, wherein the fiber Bragg grating (FBG) interrogator is connected to the fiber Bragg grating (FBG) sensors or the arrays thereof via signal transmission optical fiber cables; The individual sensors or the array sensors are installed in the tunnel and / or on man-made objects in the tunnel. The fiber Bragg grating sensors or the distributed array sensors sense environmental parameters of the tunnel and / or state parameters of man-made objects in the tunnel, and transmit the sensing signals to the fiber Bragg grating demodulator via the signal transmission optical fiber cable. The fiber Bragg grating sensor is a coordinated two-dimensional fiber Bragg grating vibration pickup, which includes a housing, in which two cantilever beams with single-dimensional vibration and equal strength are arranged; a mass block is arranged at the end of the cantilever beam, and the mass block is connected and fixed to a mass block connecting column arranged at the end of the cantilever beam; The two cantilever beams are respectively arranged on two mutually perpendicular flat plates, the ends of the two flat plates are connected and fixed to each other, each flat plate is composed of a vibration area and a shell connection area arranged on the side of the vibration area away from the other flat plate, and the shell connection area is fixedly connected to the shell; the vibration areas of the two flat plates are connected to each other, and the vibration areas are provided with slits, which are arranged along the outer contour of the vibration areas. The vibrating parts formed by the slits on the vibration areas constitute the cantilever beams, and the vibration areas are triangular or trapezoidal. The two cantilever beams are arranged in an L-shape or a straight line in space; the two flat plates are connected and fixed to realize that the two cantilever beams are simultaneously forced to vibrate, that is, they are excited at the same time by the same vibration source.

2. The signal acquisition system according to claim 1, wherein: The fiber Bragg grating sensor is one or more of a fiber Bragg grating tension sensor, a fiber Bragg grating temperature sensor, a fiber Bragg grating displacement sensor, a fiber Bragg grating gap sensor, and a fiber Bragg grating vibration sensor, and the environmental parameters and / or state parameters correspond to tension parameters, temperature parameters, displacement parameters, gap parameters, and vibration state parameters.

3. The signal acquisition system according to claim 1 or 2, wherein: The fiber Bragg grating sensor is a coordinated two-dimensional fiber Bragg grating vibration pickup, which is arranged on a fan installed in a tunnel and on a supporting structure for installing the fan. The coordinated two-dimensional fiber Bragg grating vibration pickup includes a shell, in which two cantilever beams with single-dimensional vibration and equal strength are arranged. The vibration directions of the two cantilever beams with single-dimensional vibration are perpendicular to each other. Fiber Bragg gratings are arranged on both cantilever beams with single-dimensional vibration. When the cantilever beams are forced to vibrate, the fiber Bragg grating is strained, resulting in a change in the central wavelength of the reflected light of the fiber Bragg grating.

4. The signal acquisition system according to claim 1, wherein: The fiber Bragg grating sensor or the distributed array is connected to a plurality of branch optical paths, each branch optical path is connected to the main optical cable through an optical cable junction box, and the main optical cable connects each branch optical cable to the fiber Bragg grating demodulator.

5. The signal capture system according to claim 1, wherein the fiber Bragg grating demodulator demodulates the laser light reflected from the fiber Bragg grating sensor and obtains a wavelength signal of the reflected laser light.

6. A tunnel health monitoring system, characterized in that: It comprises a signal capturing system as described in any one of claims 1 to 5; a signal processing system connected to the signal capturing system; the signal processing system analyzing the safety status of the tunnel and / or the man-made objects arranged in the tunnel based on the acquired environmental parameters of the tunnel and / or the status parameters of the man-made objects arranged in the tunnel.

7. The tunnel health monitoring system according to claim 6, characterized in that: When the state parameter is a vibration state parameter, a characteristic spectrum of the vibration of the artificial object is obtained based on the vibration state parameter, and the vibration spectrum is trended to obtain the current state of the artificial object and the remaining safe life.

8. The tunnel health monitoring system according to claim 7, characterized in that: The signal capturing system and the signal processing system are remotely connected via a wired or wireless method.

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