A two-core precise positioning optical fiber sensing early warning alarm system

Abstract

The present invention discloses a two-core precise positioning optical fiber sensing early warning alarm system, wherein the laser transmitter is a square wave signal transmitter, which transmits a square wave signal to the forward input port of the annular optical module; the forward output port of the annular optical module is connected to the forward input port of the bidirectional splitter, the bidirectional splitter divides the square wave into two, and transmits the square wave to one end of the forward core of the two-core optical fiber through the forward output port, the output end of the light refraction module is connected to the input end of the reverse core of the two-core optical fiber, the reverse output port of the bidirectional splitter is connected to the reverse input port of the annular optical module, the reverse output port of the annular optical module is connected to the laser detector, and the laser detector is connected to the signal input port of the signal processing module. The present invention utilizes an optical fiber reflector, reduces one core optical fiber, and reduces the attenuation of the entire link by one half, thereby increasing the length of optical fiber detection from the original 110 kilometers to 180 kilometers.

Description

Technical Field

[0001] The invention relates to a precise positioning alarm system, in particular to a two-core precise positioning optical fiber induction early warning alarm system. Background Art

[0002] Existing fiber optic sensing (vibration) alarm systems are divided into fiber optic Bragg grating and optical interference technology in terms of technical principles, and are divided into point type and defense zone type in terms of function. Fiber optic Bragg grating technology uses a chromatographic grating as a detection point and is a point-type perimeter intrusion alarm technology. Mach-Zehnder (M-Z) interferometer technology uses optical modules to form a defense zone and uses a single-send and single-receive system to complete the anti-vibration alarm. The single-send and single-receive alarm system has high alarm sensitivity, but it cannot accurately locate the alarm position. The distance of fiber optic signal transmission is limited, and the maximum protection range can only be 32 kilometers. The commonly used fiber optic sensing early warning alarm system is described in patent ZL201410804833.3. The laser uses a constant current source signal, and the forward and reverse optical paths of the vibration signal are both realized using three-core optical fibers, one of which is used for standard phase comparison, with a short transmission distance and large loss. With the application of square wave laser generators in the field of fiber optic sensing, the technology of using single-core fiber optic sensing for early warning alarm is gradually being used. However, the single-core fiber optic early warning alarm technology uses the refraction principle of the optical fiber itself, which has very high requirements for the laser transmitter and a short transmission distance. Summary of the invention

[0003] Purpose of the invention: The purpose of the present invention is to address the deficiencies in the prior art and provide a two-core precise positioning optical fiber sensing early warning alarm system with long transmission distance and high positioning accuracy.

[0004] Technical solution: The present invention provides a two-core precise positioning optical fiber sensing early warning alarm system to solve the above-mentioned problem, including a laser transmitter and a laser detector, and also includes a ring optical module, a bidirectional splitter, a two-core optical fiber, a light refraction module and a signal processing module.

[0005] The laser transmitter is a square wave signal transmitter, which transmits a square wave signal to the forward input port of the annular optical module; the forward output port of the annular optical module is connected to the forward input port of the bidirectional splitter, and the bidirectional splitter splits the square wave into two, and transmits the square wave to one end of the forward core of the two-core optical fiber through the forward output port, and the other end of the forward optical fiber of the two-core optical fiber is connected to the light refraction module;

[0006] The output end of the light refraction module is connected to the input end of the reverse core of the two-core optical fiber, the reverse core of the two-core optical fiber is connected to the reverse input port of the bidirectional splitter, the reverse output port of the bidirectional splitter is connected to the reverse input port of the annular light module, the reverse output port of the annular light module is connected to the laser detector, and the laser detector is connected to the signal input port of the signal processing module.

[0007] The technical solution of the present invention is further defined as follows: the signal processing module includes a signal detector, a square wave separator, a random wave separator, a square wave amplifier, a random wave amplifier and a central processing unit; the signal input port of the signal detector receives the composite wave sent by the laser detector, and transmits the composite wave to the square wave separator and the random wave separator respectively;

[0008] The square wave separated by the square wave separator output is sent to the central processing unit through the square wave amplifier;

[0009] The random wave separated by the random wave separator output is sent to the central processing unit through the random wave amplifier.

[0010] Furthermore, the central processing unit analyzes and processes the received square wave and random wave respectively, the square wave is used to directly calculate the distance, and the random wave is used for effective alarm.

[0011] Beneficial effects: The two-core precise positioning optical fiber sensing early warning alarm system provided by the present invention utilizes optical fiber reflective devices, reduces one core of optical fiber, and reduces the attenuation of the entire link by one half, thereby increasing the length of optical fiber detection from the original 110 kilometers to 180 kilometers. The present invention adds a square wave technology to measure the optical fiber distance, which reduces one receiving circuit. Originally, two optical detectors were required, but only one detector is needed after the square wave is added, which also makes the calculated distance more accurate, reaching an accuracy of 5 meters. At the same time, the present invention uses ordinary single-mode communication optical cables as front-end sensors, does not require special optical cables, does not need to increase the number of optical cable cores in sections, and the front end is a passive optical device, which is not affected by radiation, electromagnetic, and lightning interference. The front end of this system uses optical cables, which are small in size, light in weight, and variable in shape. They are not affected by factors such as the type, shape, and environment of the perimeter medium. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 A schematic diagram of the framework of a two-core precise positioning optical fiber sensing early warning alarm system provided by the present invention;

[0013] Figure 2 A schematic diagram of a signal processing module of a two-core precise positioning optical fiber sensing early warning alarm system provided by the present invention. DETAILED DESCRIPTION

[0014] The technical solution of the present invention is described in detail below with reference to the accompanying drawings, but the protection scope of the present invention is not limited to the embodiments.

[0015] Embodiment 1: This embodiment provides a two-core precise positioning optical fiber sensing early warning alarm system, the framework diagram of which is shown in FIG. Figure 1 As shown, it includes a laser transmitter 1 and a laser detector 2, a ring light module 3, a bidirectional splitter 4, a two-core optical fiber 5, a light refraction module 6 and a signal processing module (7).

[0016] like Figure 1 As shown, the laser transmitter 1 is a square wave signal transmitter, which transmits a square wave signal to the forward input port of the annular light module 3; the forward output port of the annular light module 3 is connected to the forward input port of the bidirectional splitter 4, and the bidirectional splitter 4 divides the square wave into two, and transmits it to one end of the forward core of the two-core optical fiber 5 through the forward output port, and the other end of the forward optical fiber of the two-core optical fiber 5 is connected to the light refraction module 6.

[0017] The output end of the light refraction module 6 is connected to the input end of the reverse core of the two-core optical fiber 5, the reverse core of the two-core optical fiber 5 is connected to the reverse input port of the bidirectional splitter 4, the reverse output port of the bidirectional splitter 4 is connected to the reverse input port of the annular light module 3, the reverse output port of the annular light module 3 is connected to the laser detector 2, and the laser detector 2 is connected to the signal input port of the signal processing module 7.

[0018] The schematic diagram of the signal processing module 7 is as follows Figure 2 As shown, it includes a signal detector, a square wave separator, a random wave separator, a square wave amplifier, a random wave amplifier and a central processing unit. The signal input port of the signal detector receives the composite wave sent by the laser detector 2, and transmits the composite wave to the square wave separator and the random wave separator respectively. The square wave separated by the square wave separator output is sent to the central processing unit through the square wave amplifier; the random wave separated by the random wave separator output is sent to the central processing unit through the random wave amplifier. The central processing unit analyzes and processes the received square wave and random wave respectively. The square wave is used to directly calculate the distance, and the random wave is used for effective alarm.

[0019] This solution mainly realizes square wave optical signal collection through a special square wave sending hardware structure, using a laser detector, two vibrating walls and a square wave sending laser to realize single-channel unidirectional optical signal collection.

[0020] During the working process, two kinds of optical signals are collected: the laser light source passes through optical fiber 1 - optical module 3 - optical fiber 4 - optical module 5 - optical fiber 6, 7 (vibration wall) - optical modules 8, 9 - return to optical fiber 6, 7 - through optical module 5 - through optical fiber 4 - optical module 3 - to optical fiber 2 - optical signal detector - signal collection and processing circuit - signal separation - vibration signal and square wave signal - central processing unit;

[0021] The working principle of the present invention is: when there is external force vibration at vibration point No. 1, there will be multiple irregular vibration waveforms on the square wave at position No. 1. The optical fiber distance of this method is fixed on the square wave, which is relatively stable and will not have distance deviation. The optical signal detector receives the vibration signal and analyzes it to the signal acquisition and processing circuit.

[0022] As described above, although the present invention has been shown and described with reference to specific preferred embodiments, it should not be construed as limiting the present invention itself. Various changes in form and details may be made without departing from the spirit and scope of the present invention as defined in the appended claims.

Claims

1. A two-core precise positioning optical fiber sensing early warning alarm system, comprising a laser transmitter (1) and a laser detector (2), characterized in that: It also includes a ring optical module (3), a bidirectional splitter (4), a two-core optical fiber (5), a light refraction module (6) and a signal processing module (7). The laser transmitter (1) is a square wave signal transmitter, which transmits a square wave signal to the forward input port of the annular optical module (3); the forward output port of the annular optical module (3) is connected to the forward input port of the bidirectional splitter (4); the bidirectional splitter (4) splits the square wave into two, and transmits the square wave to one end of the forward core of the two-core optical fiber (5) through the forward output port; the other end of the forward optical fiber of the two-core optical fiber (5) is connected to the light refraction module (6); The output end of the light refraction module (6) is connected to the input end of the reverse core of the two-core optical fiber (5), the reverse core of the two-core optical fiber (5) is connected to the reverse input port of the bidirectional splitter (4), the reverse output port of the bidirectional splitter (4) is connected to the reverse input port of the annular light module (3), the reverse output port of the annular light module (3) is connected to the laser detector (2), and the laser detector (2) is connected to the signal input port of the signal processing module (7); The signal processing module (7) comprises a signal detector, a square wave separator, a random wave separator, a square wave amplifier, a random wave amplifier and a central processing unit. The signal input port of the signal detector receives the composite wave sent by the laser detector (2), and transmits the composite wave to the square wave separator and the random wave separator respectively. The square wave separated by the square wave separator output is sent to the central processing unit through the square wave amplifier; The random wave separated by the random wave separator output is sent to the central processor through the random wave amplifier; The central processor analyzes and processes the received square wave and random wave respectively, the square wave is used to directly calculate the distance, and the random wave is used for effective alarm.

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