CN116698121A - Optical cable joint box state monitoring system based on grating sensing technology - Google Patents
Optical cable joint box state monitoring system based on grating sensing technology Download PDFInfo
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- G—PHYSICS
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- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
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- H—ELECTRICITY
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- H04B10/07—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems
- H04B10/071—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using a reflected signal, e.g. using optical time domain reflectometers [OTDR]
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/07—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems
- H04B10/075—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using an in-service signal
- H04B10/077—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using an in-service signal using a supervisory or additional signal
- H04B10/0771—Fault location on the transmission path
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Abstract
The application discloses an optical cable joint box state monitoring system based on a grating sensing technology, which relates to the technical field of optical communication and comprises the following components: the system comprises a grating sensing system host, communication optical cables, optical cable joint boxes and grating sensing modules, wherein a system host light outlet is connected with a reserved spare fiber core in the communication optical cables, each optical cable joint box is used for communicating a previous section of communication optical cable with a next section of communication optical cable to form a complete optical cable line, each grating sensing module is arranged in the corresponding optical cable joint box so as to meet the requirement of long-distance detection, tail fibers reserved by the grating sensing modules are welded into the optical cable line, and the system host is used for outputting an adjustable wavelength light source signal and demodulating the central wavelength offset of an optical signal reflected by each grating sensing module to obtain vibration information and temperature information of the optical cable joint box.
Description
Technical Field
The application relates to the technical field of optical communication, in particular to an optical cable connector box state monitoring system based on a grating sensing technology.
Background
The existing detection optical cable joint box is generally provided with an electronic sensor in the box, and monitors state information such as the posture, the internal temperature and the like of the joint box. According to the scheme, the solar cell panel needs to be deployed near the connector box, the hidden danger exists in the solar cell panel, the implementation is complex, and the solar cell panel is not easy to install and deploy on the optical cable iron tower; the temperature extreme condition inside the joint box can reach-40 ℃ to 70 ℃, and the working state and the service life of the electronic sensor are obviously influenced under the condition; in order to meet the long-time working requirement of the electronic sensor, a lithium battery needs to be deployed in the connector box, the working performance of the lithium battery is poor in a high-temperature environment, the ignition risk exists, and the safety of the optical cable is seriously affected; the optical cable splice box is located remotely, the electronic sensor signal back transmission needs wireless communication conditions, the current wireless communication conditions are difficult to meet the conditions of all scenes, particularly in the western and northern remote areas, and the optical cable splice box in the areas is the area most prone to accidental damage.
Therefore, it is necessary to redesign a cable splice box condition monitoring system that is suitable for long-distance, multi-splice box monitoring.
Disclosure of Invention
Aiming at the problems and the technical requirements, the inventor provides an optical cable joint box state monitoring system based on a grating sensing technology, which can meet the requirement of long-distance detection, and the technical scheme of the application is as follows:
an optical cable joint box-like condition monitoring system based on a grating sensing technology, comprising:
the optical grating sensing system host is arranged in the communication machine room and used for outputting an adjustable wavelength light source signal and demodulating the central wavelength offset of the optical signal reflected by each optical grating sensing module to obtain vibration information and temperature information of the optical cable joint box;
the optical fiber cable comprises a plurality of sections of communication optical cables, wherein a light outlet of a host computer of the grating sensing system is connected with a reserved spare fiber core in the communication optical cable;
the optical cable connector boxes are used for communicating the former section of communication optical cable with the latter section of communication optical cable to form a complete optical cable line;
each grating sensing module is installed in an optical cable joint box, and tail fibers reserved by the grating sensing modules are welded into an optical cable circuit.
The further technical scheme is that the grating sensing system host comprises:
the adjustable wavelength laser is used for emitting continuous light waves and adjusting the wavelength under the action of the controller;
the output light processing module is used for modulating the continuous light waves into pulse light signals suitable for long-distance transmission;
the circulator is used for sending the modulated pulse optical signals to an optical cable line and transmitting the reflected optical signals to the wavelength selective switch;
the wavelength selection switch is used for allowing the reflected light signal with the selected wavelength to pass through under the action of the controller;
the receiving light processing module is used for converting the reflected light signal with the selected wavelength into a corresponding electric signal;
the data processor is used for analyzing the characteristics of the electric signals, demodulating the central wavelength offset of the reflected light signals and outputting vibration information and temperature information of the optical cable joint box corresponding to the reflected light signals;
and the controller is used for controlling the light emitting wavelength of the laser, outputting pulse signal parameters of the light processing module, transmitting wavelength of the wavelength selective switch and synchronizing the clock of the data processor.
The further technical scheme is that the output light processing module comprises:
the acousto-optic modulator is used for modulating the continuous light waves into specific pulse light signals under the action of the controller;
and the optical amplifier is used for amplifying the specific pulse optical signal to obtain the pulse optical signal suitable for long-distance transmission.
The further technical scheme is that the received light processing module comprises:
a coupler for improving the quality of the reflected optical signal at the selected wavelength;
and the photoelectric detector is used for detecting the coupled reflected light signal with the selected wavelength and converting the reflected light signal into an electrical signal which can be processed.
The photoelectric detector is further used for acquiring the moment of detecting the reflected light signal through an internally integrated interferometer;
the optical signal transmission time tau calculated according to the time when the laser emits the optical signal and the time when the reflected optical signal is detected is substituted into the grating positioning formula to obtain the position information of the optical cable joint box corresponding to the reflected optical signal; the grating positioning formula is:
L＝ν·τ/2(IOR)；
wherein v is the transmission rate of the optical signal in the optical fiber, IOR is the refractive index of the optical fiber, L is the distance between the corresponding grating sensing module and the system host, and the optical cable joint box with the built-in grating sensing module is positioned to a specific geographic position by matching with the GIS map technology.
The grating sensing module comprises a frame, a first grating, a second grating, a gravity drop and two bare fiber fixing plates, wherein the first grating, the second grating, the gravity drop and the two bare fiber fixing plates are arranged in the frame; the optical fibers are wound on two opposite bare fiber fixing discs, parallel optical fiber lines are formed between the bare fiber fixing discs, the first optical grating and the second optical grating are respectively welded in any optical fiber in different optical fiber lines, the gravity drop is fixed on the first optical grating, and each bare fiber fixing disc is reserved with a bare fiber penetrating through the frame to serve as a tail fiber reserved by the optical grating sensing module; the first grating is used for detecting strain data, the second grating is used for detecting temperature data, and the gravity drop is used for converting vibration change of the optical cable joint box into stress change which can be sensed by the gratings.
The further technical scheme is that when the grating sensing system host processes the strain data returned by the first grating, the temperature data returned by the second grating is used as reference data to eliminate the interference of temperature change on the first grating, so that accurate vibration information is obtained.
In the same optical cable line, the interval wavelength between the grating sensing modules of two adjacent wave bands is not less than 4nm; in the same grating sensing module, the center wavelengths of the first grating and the second grating are separated by 8nm.
The further technical scheme is that the grating sensing module is installed in the optical cable joint box through a fixing frame.
The fixing frame comprises a base, an upper cover and a fiber coiling ring arranged on the base, wherein a positioning screw hole is reserved on the base so as to fix the base in an optical cable joint box, the fiber coiling ring is used for placing optical fibers after welding the grating sensing module and the communication optical cable, a fixing clamp is further arranged on the base, the grating sensing module is arranged in the fixing clamp, and the base is sealed with the upper cover so as to fasten the grating sensing module.
The beneficial technical effects of the application are as follows:
the application provides a passive optical cable joint box state monitoring system, which realizes grating sensing demodulation and fault distance positioning through the cooperation of a wavelength-adjustable laser and a wavelength-selective switch, and can effectively monitor the temperature and vibration conditions of a joint box; by arranging two gratings in the grating sensing module and adding a gravity drop on one grating optical fiber, vibration information can be converted into strain information which can be detected by the gratings, the influence of temperature change on the vibration detection of the gratings can be effectively eliminated, the vibration detection precision of the gratings is improved, and meanwhile, the temperature monitoring precision of the gratings is also improved; the obtained fault distance is combined with the GIS map technology, so that the monitoring object can be positioned to a specific geographic position, and the operation and maintenance efficiency is greatly improved.
Drawings
FIG. 1 is a schematic diagram of a box condition monitoring system for an optical cable connector provided by the present application.
Fig. 2 is a schematic diagram of a host of the grating sensing system provided by the application.
Fig. 3 is a schematic structural diagram of a grating sensor module provided by the present application.
Fig. 4 is a schematic view of a base structure of a fixing frame for mounting a grating sensing module according to the present application.
Detailed Description
The following describes the embodiments of the present application further with reference to the drawings.
As shown in fig. 1, the present embodiment provides a fiber cable joint box status monitoring system based on a grating sensing technology, which includes a grating sensing system host 1, a multi-section communication fiber cable 2, a plurality of fiber cable joint boxes 3 and a plurality of grating sensing modules 4. Wherein: the optical grating sensing system host 1 is arranged in a communication machine room, and an optical outlet of the optical grating sensing system host is connected with a reserved spare fiber core in the communication optical cable 2. Each cable junction box 3 communicates a preceding length of communication cable 2 with a subsequent length of communication cable 2 to form a complete cable circuit. Each grating sensing module 4 is arranged in one optical cable joint box 3, and tail fibers reserved by the grating sensing modules 4 are welded into an optical cable circuit, so that state monitoring of each optical cable joint box 3 is realized.
Optionally, the communication cable 2 is typically an aerial cable; in practical engineering, the optical cable distance between each connector box is about 3 km.
As shown in fig. 2, the grating sensing system host 1 includes a tunable wavelength laser, an output light processing module, a circulator, a wavelength selective switch, a receiving light processing module, a data processor, and a controller. Wherein:
1) The adjustable wavelength laser is used for emitting continuous highly relevant light waves, and wavelength adjustment is carried out under the action of the controller according to set parameters, such as continuous light wave range, power, interval duration and the like.
2) The output light processing module comprises an acousto-optic modulator and an optical amplifier, wherein the acousto-optic modulator is used for modulating continuous light waves into specific pulse light signals under the action of the controller. The optical amplifier adopts the erbium-doped optical fiber amplification technology and is used for amplifying specific pulse optical signals to obtain pulse optical signals suitable for long-distance transmission, thereby achieving the purpose of long-distance monitoring.
3) The characteristic of the circulator is that the optical signal can only be transmitted forward along the transmission channel designed by the circulator, the modulated pulse optical signal is sent to an optical cable line to be monitored through the circulator, when the pulse optical signal is transmitted to the corresponding grating sensing module 4, reflected light is generated and transmitted back through the optical cable, and the reflected light is transmitted to the wavelength selective switch after passing through the circulator.
4) The wavelength selective switch is used for allowing the reflected light signals with the selected wavelength to pass through under the action of the controller, and the sequence of the wavelength can be transmitted through the wavelength selective switch, so that the data processor can respectively process each reflected light signal, and the key of realizing long-distance multipoint monitoring through the grating sensing technology is realized.
5) The receiving light processing module comprises a coupler and a photoelectric detector, wherein the coupler is used for improving the quality of the reflected light signal with the selected wavelength, so that the detection sensitivity and the detection precision of the monitoring system are improved. The photoelectric detector is used for detecting the coupled reflected light signals with the selected wavelength and converting the reflected light signals into electric signals which can be processed; the photodetector is also used to acquire the moment when the reflected light signal is detected by an internally integrated interferometer.
6) The data processor is used for analyzing the characteristics of the electric signals, realizing the demodulation of the central wavelength offset of the reflected light signals and obtaining corresponding external change information. In the present embodiment, the external change information includes vibration information and temperature information of the cable joint box 3 corresponding to the reflected light signal.
7) The controller is used for controlling the light emitting wavelength of the laser, outputting pulse signal parameters of the light processing module, transmitting wavelength of the wavelength selective switch, and synchronizing the clock of the data processor.
The working principle of the grating sensing system host 1 is as follows: the light source signal with adjustable wavelength output by the light source in the system host enters the communication optical cable 2 after passing through the circulator, the grating sensing module 4 is welded in each optical cable joint box 3, when the light source signal output by the system host enters the sensing module, the light source signal with the same wavelength as the grating is reflected back by the grating and detected and demodulated after passing through the circulator, the light source signals with different grating wavelengths are continuously transmitted to the next grating sensing module 4 through the gratings, the central wavelength offset of the light signals reflected by each grating sensing module 4 is demodulated, and the vibration information, the temperature information and the position information of the optical cable joint box 3 can be obtained by matching with corresponding algorithms.
As shown in fig. 3, the grating sensing module 4 includes a frame 41, a first grating 42, a second grating 43, a weight 44, and two bare fiber fixing plates 45 disposed inside the frame 41. The connection mode is as follows: the optical fiber is wound on two opposite bare fiber fixing discs 45, and parallel optical fiber lines are formed between the bare fiber fixing discs 45; the first grating 42 and the second grating 43 are respectively welded in any optical fiber in different optical fiber lines (the optical fiber is wound between the fixed discs 45 for a plurality of circles, and the optical fiber without the grating is not shown in the figure for intuitively displaying the gratings); the gravity drop 44 passes through the first grating 42 and is fixed on the first grating, and each bare fiber fixing disc 45 reserves a certain length of bare fiber to pass through the frame 41 to serve as a tail fiber reserved by the grating sensing module 4. The first grating 42 is used for detecting strain data, the second grating 43 is used for detecting temperature data, the gravity weight 44 is used for converting vibration change of the optical cable joint box into stress change which can be sensed by the grating, and the vibration information is collected by matching with an algorithm. Optionally, the gravity drop 44 is preferably made of a material with a higher density.
Optionally, the first grating 42 and the second grating 43 are formed by optical fiber etching, the effective lengths of the grating areas of the first grating 42 and the second grating are 1cm, the corresponding wavelength selection ranges from 1500nm to 1650nm, and the optical fiber grating has various advantages of corrosion resistance, electromagnetic resistance, high temperature resistance, moisture resistance and the like, and the detection accuracy is not influenced by external environments.
Since the gratings are sensitive to strain and temperature variations, i.e. the first grating 42 is also affected by temperature variations while being affected by strain, the temperature variations will interfere with the vibration detection during the monitoring of the vibrations. The second grating 43 is not affected by vibration signals, only temperature change is collected, the collected temperature change information can be used for calculating temperature information of the connector box, and meanwhile, when the grating sensing system host 1 processes strain data returned by the first grating 42, the temperature data returned by the second grating 43 is used as reference data, so that interference of the temperature change on the first grating 42 is eliminated, and accurate vibration information is obtained.
It should be emphasized that, because the grating center wavelength variation range can reach ±2nm when the grating is affected by the conventional temperature and strain (e.g. within the range of-25 ℃ to 70 ℃), in order to avoid signal crosstalk between different grating sensing modules 4, in the same optical cable line, the interval wavelength between two used grating sensing modules of adjacent bands should be more than or equal to 4nm, for example, the grating with the center wavelength of 1550nm, and the grating center wavelengths of the adjacent bands are 1546nm and 1554nm, respectively. In addition, in the same grating sensing module 4, the center wavelength of the first grating 42 and the second grating 43 are recommended to be 8nm apart, i.e. the middle of the wavelengths of the two gratings in the same grating sensing module 4 is separated by a grating area wave band, so that the cross talk of grating signals in the same module can be effectively avoided, and meanwhile, the test error caused by overlarge wavelength difference between the first grating 42 and the second grating 43 is reduced.
The grating sensing module 4 designed in this embodiment adopts a mode of adding a gravity weight 44 on an optical fiber (preferably at the center of the grating) through the characteristic of sensitivity of the grating to temperature and strain, converts a vibration state into stress change through swinging of the gravity weight 44, and uses two gratings in a matched manner, wherein one grating is mainly used for testing strain, the other grating is only used for testing temperature, and the vibration and temperature information monitoring and the accurate temperature information monitoring of each optical cable joint box 3 are realized through data interaction between the two gratings. The installation mode of the grating sensing module 4 and the optical cable is as follows: and selecting reserved spare fiber cores for monitoring from the optical cable line, and welding tail fibers reserved by the grating sensing module 4 into the reserved fiber cores of the optical cable.
In this embodiment, the grating sensor module 4 is mounted in the cable joint box 3 by a fixing frame. As shown in fig. 4, the fixing frame includes a base 5, an upper cover (not shown in the drawing) and a fiber winding ring 51 disposed on the base 5, the base 5 is provided with positioning screw holes 52 symmetrical along the length direction so as to fix the base 5 in the optical cable connector box 3, the fiber winding ring 51 is used for placing the optical fibers after welding the grating sensing module 4 and the communication optical cable 2, and the welded optical fibers are wound on the fiber winding ring 51 to avoid winding fiber cores. The base 5 is also provided with a fixing clamp 53, and the grating sensing module 4 is arranged in the fixing clamp 53 to seal the base 5 with the upper cover so as to fasten the grating sensing module 4 and avoid loosening of the grating sensing module 4. Alternatively, the fixing clamp 53 may be implemented by a combination of a spring and a slot, or other implementations.
The principle of the grating sensing system host 1 matching with corresponding algorithm to obtain vibration information, temperature information and position information of the optical cable joint box 3 comprises the following contents:
the central wavelength of the grating reflected light is lambda B ＝2n eff Λ, the center wavelength lambda of the reflected light can be known B And the grating period lambda and the effective refractive index n of the fiber core eff Related to the following. When the external environment of the grating changes, the effective refractive index n of the fiber core eff And the grating period lambda can slightly change, when the external environment temperature and stress change act on the grating, the relative drift amount of the grating center wavelength can be described as:
in the formula (1), deltalambda B For the grating center wavelength shift, p e For effective elasto-optical coefficient, ε is the transverse strain of the fiber, α is the thermal expansion coefficient, ζ is the thermal-optical coefficient, and ΔT is the temperature variation. The drift caused by the external environment change of the central wavelengths of two different gratings along with time can be obtained by respectively recording the changes of the wavelengths corresponding to the two gratings reflected back to the data processor along with time, and the required temperature and strain change can be obtained by solving an equation set by substituting the drift into the equation (1).
The optical signal transmission time tau calculated by the optical grating sensing system host 1 according to the time when the laser emits the optical signal (direct reading) and the time when the reflected optical signal is detected is substituted into the optical grating positioning formula (2) so as to obtain the position information of the optical cable joint box 3 corresponding to the reflected optical signal.
L＝ν·τ/2(IOR) (2)
In the formula (2), v is the transmission rate of an optical signal in an optical fiber, IOR is the refractive index of the optical fiber, and L is the distance between the corresponding grating sensing module 4 and a system host, and the optical cable joint box 3 with the built-in grating sensing module 4 is positioned to a specific geographic position by matching with a GIS map technology.
Compared with a state monitoring system formed by an active electronic sensor, 1) the system does not need to provide a power supply in a monitoring optical cable line, is simple to implement, namely, is a passive optical cable joint box state monitoring system, realizes grating sensing demodulation and fault distance positioning by matching the wavelength-adjustable laser with the wavelength-selective switch, and can effectively monitor the temperature and vibration conditions of the joint box. If the temperature is monitored, a user can pertinently maintain the junction box with the hidden danger of icing in advance, so that the damage to the optical cable caused by icing is avoided. If to the control of vibration, can effectively monitor whether the splice box installation is firm, avoid the splice box not hard up, cause the splice box to drop, influence optical cable safety. 2) The grating used in the application is prepared by optical fiber etching, and the service life of the grating is longer than that of an active electronic sensor. 3) The monitored communication optical cable body can be used as a signal transmission channel, the monitoring information does not need an additional auxiliary means, and the detection signal can be transmitted to the system host in a long distance.
Compared with a state monitoring system formed by adopting a distributed optical fiber sensing technology, 1) the system has high test precision and can achieve centimeter-level distance resolution under the long-distance condition. 2) The test processing result is quick, and the whole line data volume processing can be completed within 5 seconds. 3) The test distance is long, the reflectivity of the grating to specific optical signals is high, and the reflected light can realize long-distance transmission. 4) The influence of temperature change on vibration test can be effectively reduced, and the vibration parameter test precision is improved. 5) The system can distinguish the position of the connector box under the condition of long-distance optical cables.
The optical cable joint box state monitoring system based on the grating sensing technology can be used for monitoring the box state of an optical cable joint box, and can also play an excellent role in other fields needing to monitor vibration, such as special application scenes where some active sensing equipment cannot work, and various application scenes such as geological exploration, perimeter protection, mechanical equipment running state monitoring and the like.
The above is only a preferred embodiment of the present application, and the present application is not limited to the above examples. It is to be understood that other modifications and variations which may be directly derived or contemplated by those skilled in the art without departing from the spirit and concepts of the present application are deemed to be included within the scope of the present application.
Claims (10)
1. The utility model provides a box state monitored control system of optical cable joint based on grating sensing technique which characterized in that includes:
the optical grating sensing system host is arranged in the communication machine room and used for outputting an adjustable wavelength light source signal and demodulating the central wavelength offset of the optical signal reflected by each optical grating sensing module to obtain vibration information and temperature information of the optical cable joint box;
the optical fiber cable comprises a plurality of sections of communication optical cables, wherein a light outlet of a host computer of the grating sensing system is connected with a reserved spare fiber core in the communication optical cable;
each optical cable joint box is used for communicating a front section of communication optical cable with a rear section of communication optical cable to form a complete optical cable line;
and the tail fibers reserved by the grating sensing modules are welded into the optical cable circuit.
2. The system for monitoring the box condition of a fiber optic cable joint based on the grating sensing technology of claim 1, wherein the host computer of the grating sensing system comprises:
the adjustable wavelength laser is used for emitting continuous light waves and adjusting the wavelength under the action of the controller;
the output light processing module is used for modulating the continuous light waves into pulse light signals suitable for long-distance transmission;
the circulator is used for sending the modulated pulse optical signals to the optical cable line and transmitting the reflected optical signals to the wavelength selective switch;
the wavelength selection switch is used for allowing the reflected light signal with the selected wavelength to pass through under the action of the controller;
the receiving light processing module is used for converting the reflected light signal with the selected wavelength into a corresponding electric signal;
the data processor is used for analyzing the characteristics of the electric signals, demodulating the central wavelength offset of the reflected light signals and outputting vibration information and temperature information of the optical cable joint box corresponding to the reflected light signals;
and the controller is used for controlling the light emitting wavelength of the laser, the pulse signal parameter of the output light processing module, the transparent transmission wavelength of the wavelength selection switch and synchronizing the clock of the data processor.
3. The system for monitoring the box condition of a fiber optic cable joint based on the grating sensing technology according to claim 2, wherein the output light processing module comprises:
the acousto-optic modulator is used for modulating the continuous light waves into specific pulse light signals under the action of the controller;
and the optical amplifier is used for amplifying the specific pulse optical signal to obtain a pulse optical signal suitable for long-distance transmission.
4. The system for monitoring the box condition of a fiber optic cable joint based on the grating sensing technology according to claim 2, wherein the received light processing module comprises:
a coupler for improving the quality of the reflected optical signal at the selected wavelength;
and the photoelectric detector is used for detecting the coupled reflected light signal with the selected wavelength and converting the reflected light signal into an electrical signal which can be processed.
5. The system for monitoring the box-like condition of a fiber optic cable joint based on the grating sensing technology according to claim 4, wherein the photoelectric detector is further used for acquiring the moment when the reflected light signal is detected through an internally integrated interferometer;
the main machine of the grating sensing system is also used for calculating the transmission time tau of the optical signal according to the time when the laser emits the optical signal and the time when the reflected optical signal is detected, and substituting the transmission time tau into a grating positioning formula to obtain the position information of the optical cable joint box corresponding to the reflected optical signal; the grating positioning formula is as follows:
L＝ν·τ/2(IOR)；
wherein v is the transmission rate of the optical signal in the optical fiber, IOR is the refractive index of the optical fiber, L is the distance between the corresponding grating sensing module and the system host, and the optical cable joint box with the built-in grating sensing module is positioned to a specific geographic position by matching with the GIS map technology.
6. The optical cable joint box-like condition monitoring system based on the grating sensing technology according to claim 1, wherein the grating sensing module comprises a frame, a first grating, a second grating, a gravity drop and two bare fiber fixing discs, wherein the first grating, the second grating, the gravity drop and the two bare fiber fixing discs are arranged in the frame; the optical fibers are wound on two opposite bare fiber fixing discs, parallel optical fiber lines are formed between the bare fiber fixing discs, the first optical grating and the second optical grating are respectively welded in any optical fiber in different optical fiber lines, the gravity drop is fixed on the first optical grating, and each bare fiber fixing disc reserves a bare fiber with a certain length to pass through the frame and serve as a tail fiber reserved by the grating sensing module; the first grating is used for detecting strain data, the second grating is used for detecting temperature data, and the gravity pendant is used for converting vibration change of the optical cable joint box into stress change which can be sensed by the grating.
7. The system for monitoring the box-like condition of an optical cable connector based on the grating sensing technology according to claim 6, wherein when the host computer of the grating sensing system processes the strain data returned by the first grating, the temperature data returned by the second grating is used as reference data to eliminate the interference of temperature change on the first grating, so that accurate vibration information is obtained.
8. The system for monitoring the box-like condition of an optical cable joint based on the grating sensing technology according to claim 6, wherein the wavelength of the interval between the grating sensing modules of two adjacent wave bands used in the same optical cable line is not less than 4nm; in the same grating sensing module, the central wavelengths of the first grating and the second grating are separated by 8nm.
9. The system for monitoring the box-like condition of a fiber optic cable joint based on the grating sensing technology according to claim 1, wherein the grating sensing module is installed in the fiber optic cable joint box through a fixing frame.
10. The optical cable joint box-like condition monitoring system based on the grating sensing technology according to claim 9, wherein the fixing frame comprises a base, an upper cover and a disc fiber ring arranged on the base, wherein a positioning screw hole is reserved on the base so as to fix the base in the optical cable joint box, the disc fiber ring is used for placing an optical fiber after the grating sensing module is welded with the communication optical cable, a fixing clamp is further arranged on the base, the grating sensing module is arranged in the fixing clamp, and the base is sealed with the upper cover so as to fasten the grating sensing module.
Priority Applications (1)
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