Apparatus and method for detecting intrusion by using fiber Bragg grating sensor

Abstract

Disclosed are an apparatus and a method for detecting intrusion by using fiber Bragg grating (FBG) sensors. the apparatus includes a measurement system, an optical fiber for transmitting and detecting optical signals, and a plurality of FBG sensors installed in intrusion detection areas together with the optical fiber and representing reflective wavelengths different from each other. The method includes the steps of installing the optical fiber and the FBG sensors in predetermined intrusion areas, continuously measuring wavelength variation or wavelength intensity of the optical fiber by using the measurement system, and comparing the measured wavelength variation or measured wavelength intensity of the optical fiber with a reference value, thereby determining intrusion of an intruder. Since the apparatus includes the optical switch and the optical distributor, the system establishment cost is reduced, the intrusion detection area is enlarged, and plural independent intrusion detection areas are formed.

Description

technical field [0001] The present invention relates to apparatus and methods for detecting intrusions using Fiber Bragg Grating (FBG) sensors. More particularly, the present invention relates to such an apparatus and method for detecting intrusions using a Fiber Bragg Grating (FBG) sensor, wherein the FBG sensor or the FBG strain sensor and the FBG vibration sensor are attached to a fence such as barbed wire so that based on the applied Intrusion is detected by physical pressure on the barrier and disconnection of optical transmission lines. Background technique [0002] Typically, the intrinsic wavelength of a Fiber Bragg Grating (FBG) sensor changes according to the physical pressure applied to the FBG sensor. If the optical transmission path is shortened, the reflected wavelength intensity of the FBG sensor decreases. Therefore, it is possible to accurately detect an intruder and an intrusion position based on a physical pressure applied to the fence and a disconnectio...

AI Technical Summary

Problems solved by technology

However, since rigid parts are provided in addition to optical fibers, the weight and volume of the intrusion protection system increase, so that it frequently breaks down when the intrusion protection system is affected by rain, wind, and snow, and due to the Tares the intrusion protection system or falsely sounds an alarm when it is under the influence of an animal

[0005] In addition, the OTDR system is very complicated and expensive, and due to its unique measurement scheme, the OTDR system does not apply an optical splitter such as an optical coupler, so the OTDR system must use a strand of optical fiber to detect a fence with a length of 200m

Therefore, if the fiber breaks 20m from the front of the fence, the OTDR system cannot detect an intruder breaking through the rest of the fence (180m)

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