A new type of intelligent all-fiber perimeter alarm system with measurable distance

Abstract

The present invention relates to the field of perimeter protection technology, and provides a new type of intelligent all-fiber perimeter alarm system with measurable distance, including: a fiber optic intrusion detector, a first transmission fiber, a head-end data transmission module, a sensing fiber, a terminal data transmission module, a host computer, and a second transmission fiber; the fiber optic intrusion detector is connected to the head-end data transmission module through the first transmission fiber; the fiber optic intrusion detector includes: a narrow bandwidth laser, a first photodetector, a second photodetector, and an acquisition card installed together; the head-end data transmission module is connected to the terminal data transmission module through the sensing fiber; the head-end data transmission module includes: a beam splitter, a first fiber isolator, a second fiber isolator, a first coupler, and a second coupler; the beam splitter is arranged corresponding to the narrow bandwidth laser, the narrow bandwidth laser emits laser, and the beam splitter splits the laser into two laser beams. The present invention can realize long-distance monitoring and improve detection sensitivity and positioning accuracy.

Description

Technical Field

[0001] The invention relates to the technical field of perimeter protection, and in particular to a novel intelligent all-optical perimeter alarm system with measurable distance. Background Art

[0002] With the advancement of technology and the development of society, people's demand for security is increasing and their requirements are getting higher and higher, especially in the field of large-scale infrastructure.

[0003] Airports are places with concentrated passenger flow and high security requirements. In recent years, airport invasion incidents have frequently occurred. Pipeline transportation has the advantages of safety, economy, quality assurance, and pollution-free, and has been widely used at home and abroad. However, oil and gas pipelines have the characteristics of high temperature, high pressure, flammability and explosion. The activities of oil thieves and engineering vehicles on the pipelines will bring major safety hazards to their normal operations. Therefore, how to timely discover and accurately locate the above-mentioned destructive behaviors and send early warning signals to managers in a timely and accurate manner is an urgent problem to be solved in order to prevent pipeline leakage accidents.

[0004] Traditional security technologies such as video surveillance, manual patrols, electronic fences, infrared beams, etc. are greatly limited in application due to the defects of the technology itself. For example, video surveillance and manual patrols are heavily dependent on the quality of staff and weather conditions. If the light is very dim, they are almost useless. Technologies such as electronic fences and infrared beams require outdoor power supply, are greatly affected by the weather, and are not suitable for long-distance monitoring. Therefore, traditional sensors are difficult to meet the basic requirements of modern perimeter protection systems, such as wide monitoring range, low false alarm rate, strong anti-interference, low cost, and simple maintenance. The traditional pipeline monitoring method is to detect some physical or chemical phenomena after the leak occurs, but these methods cannot prevent the occurrence of leak accidents.

[0005] There are other fiber optic perimeter protection systems, such as distributed sensing systems based on Michelson interferometry technology, which require high interference signal demodulation technology and system stability, which is not conducive to achieving real-time positioning; distributed sensing systems based on backscattering OTDR technology have complex demodulation methods and cannot achieve real-time monitoring of continuous event disturbances. Summary of the invention

[0006] The present invention mainly solves the technical problems of limited monitoring range, high false alarm rate, poor anti-interference of traditional sensors, and the fact that the distributed sensing system of existing Michelson interferometry technology is not conducive to achieving real-time positioning. A new type of intelligent all-fiber perimeter alarm system with measurable distance is proposed. The system has a simple structure to achieve long-distance monitoring, improve detection sensitivity and positioning accuracy, and reduce costs.

[0007] The present invention provides a new type of distance-measurable intelligent all-fiber perimeter alarm system, comprising: an optical fiber intrusion detector, a first conductive optical fiber, a head-end data transmission module, a sensing optical fiber, a terminal data transmission module, a host computer, and a second conductive optical fiber;

[0008] The optical fiber intrusion detector is connected to the head-end data transmission module via a first transmission optical fiber;

[0009] The optical fiber intrusion detector comprises: a narrow bandwidth laser, a first photoelectric detector, a second photoelectric detector and an acquisition card installed together;

[0010] The head-end data transmission module is connected to the terminal data transmission module via a sensing optical fiber;

[0011] The head-end data transmission module comprises: a beam splitter, a first optical fiber isolator, a second optical fiber isolator, a first coupler and a second coupler;

[0012] The beam splitter is arranged corresponding to the narrow bandwidth laser, the narrow bandwidth laser emits laser light, and the beam splitter splits the laser light into two laser beams;

[0013] The first laser beam enters the first coupler through the first optical fiber isolator, and the first coupler is connected to the terminal data transmission module through the sensing optical fiber; the first coupler is also connected to the first photoelectric detector;

[0014] The second laser beam enters the second coupler through the second optical fiber isolator, and the second coupler is connected to the terminal data transmission module through the second transmission optical fiber; the second coupler is also connected to the second photoelectric detector;

[0015] The first photoelectric detector and the second photoelectric detector are connected to the acquisition card respectively; the acquisition card is connected to the host computer;

[0016] When an intrusion occurs, the sensing optical fiber undergoes a phase change due to the intrusion behavior, forming interference fringes in the first coupler and another interference fringes in the second coupler. The first coupler transmits the generated interference fringes to the first photodetector, and the second coupler transmits the generated interference fringes to the second photodetector. The first photodetector and the second photodetector convert the optical signal into an electrical signal and transmit it to the acquisition card. The host computer receives the signal from the acquisition card, determines the type and location of the intrusion, and issues an alarm.

[0017] Preferably, it also includes: a microwave array module connected to the host computer;

[0018] The microwave array module monitors the object. Before an intrusion occurs, when an object enters the monitoring range of the microwave array module, the microwave array module provides position feedback and issues a pre-alarm until an intrusion occurs.

[0019] Preferably, the terminal data transmission module includes: a third coupler.

[0020] Preferably, the intelligent all-fiber perimeter alarm system is arranged in the fence of the protective place, and a blade-type barbed wire is set above the fence of the protective place.

[0021] Preferably, the intelligent all-optical fiber perimeter alarm system is arranged above the oil pipeline.

[0022] The present invention provides a new type of distance-measurable intelligent all-fiber perimeter alarm system, which has a simple structure, high detection sensitivity, high positioning accuracy, simple demodulation method, and low cost. The all-fiber perimeter alarm system is built using Mach-Zehnder interference technology, which can achieve long-distance unmanned monitoring. At the same time, since the demodulation of optical interference fringes is relatively easy, the advantages of reducing technical requirements and reducing costs can be achieved. At the same time, a microwave array ranging module is set up to accurately measure the distance between the intruding object and the protection field. Through the combination of active and passive methods, the system of the present invention can also achieve accurate alarms in harsh environments such as strong winds. At the same time, the accuracy of the alarm can be greatly improved in other normal environments, thereby reducing the false alarm rate. The present invention can achieve the integrated function of active alarm and passive alarm by simultaneously linking the camera. The present invention has important application value in the field of perimeter security. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a connection diagram of a novel intelligent all-optical fiber perimeter alarm system with measurable distance provided by the present invention;

[0024] Figure 2 It is a schematic diagram of the configuration of the new intelligent all-optical fiber perimeter alarm system with measurable distance provided by the present invention in a protection field;

[0025] Figure 3 The present invention is a schematic diagram of the configuration of a novel intelligent all-optical fiber perimeter alarm system with measurable distance in a petroleum pipeline.

[0026] Figure numerals: 1. Fiber optic intrusion detector; 101. narrow bandwidth laser; 102. first photodetector; 103. second photodetector; 2. first transmission optical fiber; 3. head-end data transmission module; 301. beam splitter; 302. first optical fiber isolator; 303. second optical fiber isolator; 304. first coupler; 305. second coupler; 601. third coupler; 4. sensing optical fiber; 5. razor-blade barbed wire; 6. terminal data transmission module; 7. protective site fence; 8. microwave array module; 9. second transmission optical fiber; 10. oil pipeline. DETAILED DESCRIPTION

[0027] In order to make the technical problems solved by the present invention, the technical solutions adopted and the technical effects achieved clearer, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for the convenience of description, only the parts related to the present invention are shown in the accompanying drawings, rather than all the contents.

[0028] like Figure 1 As shown, the distance-measurable novel intelligent all-fiber perimeter alarm system provided by the embodiment of the present invention includes: a fiber optic intrusion detector 1, a first conductive optical fiber 2, a head-end data transmission module 3, a sensing optical fiber 4, a terminal data transmission module 6, a host computer and a second conductive optical fiber 9.

[0029] The optical fiber intrusion detector 1 is connected to the head-end data transmission module 3 via the first transmission optical fiber 2. The optical fiber intrusion detector 1 comprises: a narrow bandwidth laser 101, a first photoelectric detector 102, a second photoelectric detector 103 and a collection card installed together.

[0030] The narrow bandwidth laser 101 has the function of emitting a laser beam to provide a light source for the head-end data transmission module 3, causing the phase of the sensing optical fiber 4 to change to generate interference fringes; the photodetector in this embodiment has the function of receiving the interference fringes signal transmitted by the sensing optical fiber.

[0031] The head-end data transmission module 3 is connected to the end-end data transmission module 6 via the sensing optical fiber 4; the end-end data transmission module 6 comprises: a third coupler 601. The head-end data transmission module 3 comprises: a beam splitter 301, a first optical fiber isolator 302, a second optical fiber isolator 303, a first coupler 304 and a second coupler 305;

[0032] The beam splitter 301 is arranged corresponding to the narrow bandwidth laser 101. The narrow bandwidth laser 101 emits laser light, and the beam splitter 301 splits the laser light into two laser beams according to a certain splitting ratio.

[0033] The first laser beam enters the first coupler 304 through the first optical fiber isolator 302. The first coupler 304 is connected to the terminal data transmission module 6 through the sensing optical fiber 4. The first coupler 304 is also connected to the first photodetector 102.

[0034] The second laser beam enters the second coupler 305 through the second optical fiber isolator 303. The second coupler 305 is connected to the terminal data transmission module 6 through the second transmission optical fiber 9. The second coupler 305 is also connected to the second photodetector 103.

[0035] The first photoelectric detector 102 and the second photoelectric detector 103 are connected to the acquisition card respectively; the acquisition card is connected to the host computer. The host computer has functions such as a friendly interactive interface.

[0036] The first fiber isolator 302 and the second fiber isolator 303 have the function of preventing reflected light from entering the coupler. The sensing fiber 4 has the function of sensing the intrusion signal as a condition for generating interference. The sensing fiber 4 is distributed on the perimeter according to the needs. When the intrusion point occurs on the sensing fiber 4, the phase of the sensing fiber 4 changes. Interference occurs at the sensing fiber 4. The two light sources are obtained by splitting the light of the same narrow bandwidth laser 101. When interference occurs, the phase difference of the two paths is constant and the propagation direction is the same, so the generation of interference fringes is satisfied. The optical path connection of the two laser beams split by the beam splitter 301 satisfies the Mach-Zehnder interference technology and satisfies the forward and reverse interference.

[0037] On the basis of the above scheme, the distance measurable new intelligent all-fiber perimeter alarm system of this embodiment further includes: a microwave array module 8 connected to the host computer. The number of microwave array modules 8 can be multiple, and multiple microwave array modules 8 are arranged at equal intervals. The microwave array module 8 can play a role in real-time distance monitoring. The microwave array module 8 monitors the object. Before the intrusion occurs, when an object enters the monitoring range of the microwave array module 8, the microwave array module 8 continuously provides position feedback to the host computer and issues a pre-alarm until the intrusion occurs.

[0038] When an intrusion occurs, the sensing optical fiber 4 undergoes a phase change due to the intrusion behavior, forming interference fringes in the first coupler 304 and another interference fringes in the second coupler 305. The first coupler 304 transmits the generated interference fringes to the first photodetector 102, and the second coupler 305 transmits the generated interference fringes to the second photodetector 103. The first photodetector 102 and the second photodetector 103 convert the optical signal into an electrical signal and transmit it to the acquisition card. The host computer receives the signal from the acquisition card, determines the intrusion type and location, and issues an alarm. Specifically, the intrusion location is determined by cross-correlation and other algorithms, and the intrusion behavior is compared with the action library to determine the intrusion action type. This embodiment uses Mach-Zehnder interferometry technology, which can achieve long-distance monitoring and has high detection sensitivity.

[0039] The distance-measurable new intelligent all-fiber perimeter alarm system of this embodiment can be arranged in different application scenarios using different fiber optic laying methods. Figure 2 As shown, the intelligent all-fiber perimeter alarm system is arranged in the protective site fence 7, and a razor-shaped barbed wire 5 is arranged above the protective site fence 7. The razor-shaped barbed wire 5 and the protective site fence 7 constitute the supporting structure of the present intelligent all-fiber perimeter alarm system. Figure 3 As shown, the intelligent all-fiber perimeter alarm system is arranged above the oil pipeline 10.

[0040] The present invention uses Mach-Zehnder interferometer technology to build an all-fiber perimeter alarm system with a simple structure, high detection sensitivity, high positioning accuracy, and a simple demodulation method. It can realize long-distance unmanned monitoring. At the same time, since the demodulation of optical interference fringes is relatively easy, it can achieve the advantages of reducing technical requirements and reducing costs. In conjunction with the host computer, the location and type of intrusion can be determined with high accuracy. At the same time, a microwave array module is set up to accurately measure the distance between the intruding object and the protection field. Through the combination of active and passive methods, the system of the present invention can also achieve accurate alarms in harsh environments such as strong winds. At the same time, it can greatly improve the accuracy of the alarm under other normal environments, thereby reducing the false alarm rate.

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that modifying the technical solutions described in the aforementioned embodiments, or replacing some or all of the technical features therein by equivalents, does not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A new type of intelligent all-fiber perimeter alarm system with measurable distance, characterized in that: include: Optical fiber intrusion detector (1), a first transmission optical fiber (2), a head-end data transmission module (3), a sensing optical fiber (4), a terminal data transmission module (6), a host computer, and a second transmission optical fiber (9); The optical fiber intrusion detector (1) is connected to a head-end data transmission module (3) via a first transmission optical fiber (2); The optical fiber intrusion detector (1) comprises: a narrow bandwidth laser (101), a first photoelectric detector (102), a second photoelectric detector (103) and an acquisition card installed together; The head-end data transmission module (3) is connected to the end-end data transmission module (6) via a sensing optical fiber (4); The head-end data transmission module (3) comprises: a beam splitter (301), a first optical fiber isolator (302), a second optical fiber isolator (303), a first coupler (304) and a second coupler (305); The beam splitter (301) is arranged corresponding to the narrow bandwidth laser (101); the narrow bandwidth laser (101) emits laser light, and the beam splitter (301) splits the laser light into two beams of laser light; The first laser beam enters the first coupler (304) through the first optical fiber isolator (302); the first coupler (304) is connected to the terminal data transmission module (6) through the sensing optical fiber (4); the first coupler (304) is also connected to the first photoelectric detector (102); The second laser beam enters the second coupler (305) through the second optical fiber isolator (303); the second coupler (305) is connected to the terminal data transmission module (6) through the second transmission optical fiber (9); the second coupler (305) is also connected to the second photoelectric detector (103); The first photoelectric detector (102) and the second photoelectric detector (103) are respectively connected to an acquisition card; the acquisition card is connected to a host computer; When an intrusion occurs, the sensing optical fiber (4) undergoes a phase change due to the intrusion behavior, forming an interference fringe in the first coupler (304) and another interference fringe in the second coupler (305). The first coupler (304) transmits the generated interference fringe to the first photodetector (102), and the second coupler (305) transmits the generated interference fringe to the second photodetector (103). The first photodetector (102) and the second photodetector (103) convert the optical signal into an electrical signal and transmit it to the acquisition card. The host computer receives the signal from the acquisition card, determines the intrusion type and intrusion location, and issues an alarm. The novel distance-measurable intelligent all-fiber perimeter alarm system further comprises: a microwave array module (8) connected to a host computer; the microwave array module (8) monitors an object, and before an intrusion occurs, when an object enters the monitoring range of the microwave array module (8), the microwave array module (8) performs position feedback and issues a pre-alarm until an intrusion occurs; The terminal data transmission module (6) comprises: a third coupler (601); The intelligent all-fiber perimeter alarm system is arranged in a protective site fence (7), and a razor-shaped barbed wire (5) is arranged above the protective site fence (7); The intelligent all-optical fiber perimeter alarm system is arranged above the oil pipeline (10).

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